K. Bechtol - The DES Collaboration

K. Bechtol
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K. Bechtol
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The DES Collaboration
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High Energy Astrophysical Phenomena (33)
 
Astrophysics of Galaxies (24)
 
Cosmology and Nongalactic Astrophysics (17)
 
Instrumentation and Methods for Astrophysics (6)
 
High Energy Physics - Experiment (5)
 
Solar and Stellar Astrophysics (3)
 
High Energy Physics - Phenomenology (3)
 
General Relativity and Quantum Cosmology (1)
 
Earth and Planetary Astrophysics (1)

Publications Authored By K. Bechtol

Recent discovery of many dwarf satellite galaxies in the direction of the Small and Large Magellanic Clouds (SMC and LMC) provokes questions of their origins, and what they can reveal about galaxy evolution theory. Here, we predict the satellite stellar mass function of Magellanic Cloud-mass host galaxies using abundance matching and reionization models applied to the Caterpillar simulations. Specifically focusing on the volume within 50 kpc of the LMC, we predict a mean of 4-8 satellites with stellar mass $M_* > 10^4 \, \mathrm{M_\odot}$, and 3-4 satellites with $80 < M_* \leq 3000 \, \mathrm{M_\odot}$. Read More

We characterize the ability of the Dark Energy Camera (DECam) to perform relative astrometry across its 500~Mpix, 3 deg^2 science field of view, and across 4 years of operation. This is done using internal comparisons of ~4x10^7 measurements of high-S/N stellar images obtained in repeat visits to fields of moderate stellar density, with the telescope dithered to move the sources around the array. An empirical astrometric model includes terms for: optical distortions; stray electric fields in the CCD detectors; chromatic terms in the instrumental and atmospheric optics; shifts in CCD relative positions of up to ~10 um when the DECam temperature cycles; and low-order distortions to each exposure from changes in atmospheric refraction and telescope alignment. Read More

Chemically peculiar stars in dwarf galaxies provide a window for exploring the birth environment of stars with varying chemical enrichment. We present a chemical abundance analysis of the brightest star in the newly discovered ultra-faint dwarf galaxy candidate Tucana III. Because it is particularly bright for a star in an ultra-faint Milky Way satellite, we are able to measure the abundance of 28 elements, including 13 neutron-capture species. Read More

We report the observation and physical characterization of the possible dwarf planet \UZ\ ("DeeDee"), a dynamically detached trans-Neptunian object discovered at 92 AU. This object is currently the second-most distant known trans-Neptunian object with reported orbital elements, surpassed in distance only by the dwarf planet Eris. The object was discovered with an $r$-band magnitude of 23. Read More

We report the discovery and spectroscopic confirmation of the quad-like lensed quasar system DES J0408-5354 found in the Dark Energy Survey (DES) Year 1 (Y1) data. This system was discovered during a search for DES Y1 strong lensing systems using a method that identified candidates as red galaxies with multiple blue neighbors. DES J0408-5354 consists of a central red galaxy surrounded by three bright (i < 20) blue objects and a fourth red object. Read More

Measurements of the galaxy stellar mass function are crucial to understand the formation of galaxies in the Universe. In a hierarchical clustering paradigm it is plausible that there is a connection between the properties of galaxies and their environments. Evidence for environmental trends has been established in the local Universe. Read More

We report the discovery of a stellar over-density 8$^{\circ}$ north of the center of the Small Magellanic Cloud (Small Magellanic Cloud Northern Over-Density; SMCNOD) using data from the first two years of the Dark Energy Survey (DES) and the first year of the MAGellanic SatelLITEs Survey (MagLiteS). The SMCNOD is indistinguishable in age, metallicity and distance from the nearby SMC stars, being primarly composed of intermediate-age stars (6 Gyr, Z=0.001), with a small fraction of young stars (1 Gyr, Z=0. Read More

The coalescence of a binary neutron star (BNS) pair is expected to produce gravitational waves (GW) and electromagnetic (EM) radiation, both of which may be detectable with currently available instruments. We describe a search for a theoretically predicted r-process optical transient from these mergers, dubbed the kilonova (KN), using griz broadband data from the Dark Energy Survey Supernova Program (DES-SN). Some models predict KNe to be redder, shorter-lived, and dimmer than supernovae (SNe), but at present the event rate of KNe is poorly constrained. Read More

We search for excess gamma-ray emission coincident with the positions of confirmed and candidate Milky Way satellite galaxies using 6 years of data from the Fermi Large Area Telescope (LAT). Our sample of 45 stellar systems includes 28 kinematically confirmed dark-matter-dominated dwarf spheroidal galaxies (dSphs) and 17 recently discovered systems that have photometric characteristics consistent with the population of known dSphs. For each of these targets, the relative predicted gamma-ray flux due to dark matter annihilation is taken from kinematic analysis if available, and estimated from a distance-based scaling relation otherwise, assuming that the stellar systems are dark-matter-dominated dSphs. Read More

We report a new ultra-faint stellar system found in Dark Energy Camera data from the first observing run of the Magellanic Satellites Survey (MagLiteS). MagLiteS J0644-5953 (Pictor II or Pic II) is a low surface brightness ({\mu} = 28.5 mag arcsec$^{-2}$ within its half-light radius) resolved overdensity of old and metal-poor stars located at a heliocentric distance of 45 kpc. Read More

We estimate the conventional astrophysical emission from dwarf spheroidal satellite galaxies (dSphs) of the Milky Way, focusing on millisecond pulsars (MSPs), and evaluate the potential for confusion with dark matter (DM) annihilation signatures at GeV energies. In low-density stellar environments, such as dSphs, the abundance of MSPs is expected to be proportional to stellar mass. Accordingly, we construct the $\gamma$-ray luminosity function of MSPs in the Milky Way disk, where $>90$ individual MSPs have been detected with the $\textit{Fermi}$ Large Area Telescope (LAT), and scale this luminosity function to the stellar masses of 30 dSphs to estimate the cumulative emission from their MSP populations. Read More

2016Jun

We report the results of a Dark Energy Camera (DECam) optical follow-up of the gravitational wave (GW) event GW151226, discovered by the Advanced LIGO detectors. Our observations cover 28.8 deg$^2$ of the localization region in the $i$ and $z$ bands (containing 3% of the BAYESTAR localization probability), starting 10 hours after the event was announced and spanning four epochs at $2-24$ days after the GW detection. Read More

A promising method for further measurements of high energy neutrinos at the PeV scale and above is through an in-ice radio interferometric phased array, designed to look for Askaryan emission from neutrinos interacting in large volumes of glacial ice. Such a detector would be sensitive to two populations of neutrinos: the PeV-scale astrophysical neutrino flux recently detected by IceCube, and the predicted cosmogenic ultra-high energy (UHE) flux ($E>10^{17}$ eV). Characterizing these high energy neutrino populations is an important step toward understanding the most energetic cosmic accelerators, and the discovery of UHE neutrinos would allow us to probe fundamental physics at energy scales that are not achievable on Earth. Read More

The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect search techniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of the $\gamma$-ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 MeV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. Read More

We present results from sensitive, multi-epoch NuSTAR observations of the late-type star-forming galaxy M83 (d=4.6 Mpc), which is the first investigation to spatially resolve the hard (E>10 keV) X-ray emission of this galaxy. The nuclear region and ~ 20 off-nuclear point sources, including a previously discovered ultraluminous X-ray (ULX) source, are detected in our NuSTAR observations. Read More

2016Jan
Authors: Dark Energy Survey Collaboration, T. Abbott, F. B. Abdalla, J. Aleksic, S. Allam, A. Amara, D. Bacon, E. Balbinot, M. Banerji, K. Bechtol, A. Benoit-Levy, G. M. Bernstein, E. Bertin, J. Blazek, C. Bonnett, S. Bridle, D. Brooks, R. J. Brunner, E. Buckley-Geer, D. L. Burke, G. B. Caminha, D. Capozzi, J. Carlsen, A. Carnero-Rosell, M. Carollo, M. Carrasco-Kind, J. Carretero, F. J. Castander, L. Clerkin, T. Collett, C. Conselice, M. Crocce, C. E. Cunha, C. B. D'Andrea, L. N. da Costa, T. M. Davis, S. Desai, H. T. Diehl, J. P. Dietrich, S. Dodelson, P. Doel, A. Drlica-Wagner, J. Estrada, J. Etherington, A. E. Evrard, J. Fabbri, D. A. Finley, B. Flaugher, R. J. Foley, P. Rosalba, J. Frieman, J. Garcia-Bellido, E. Gaztanaga, D. W. Gerdes, T. Giannantonio, D. A. Goldstein, D. Gruen, R. A. Gruendl, P. Guarnieri, G. Gutierrez, W. Hartley, K. Honscheid, B. Jain, D. J. James, T. Jeltema, S. Jouvel, R. Kessler, A. King, D. Kirk, R. Kron, K. Kuehn, N. Kuropatkin, O. Lahav, T. S. Li, M. Lima, H. Lin, M. A. G. Maia, M. Makler, M. Manera, C. Maraston, J. L. Marshall, P. Martini, R. G. McMahon, P. Melchior, A. Merson, C. J. Miller, R. Miquel, J. J. Mohr, X. Morice-Atkinson, K. Naidoo, E. Neilsen, R. C. Nichol, B. Nord, R. Ogando, F. Ostrovski, A. Palmese, A. Papadopoulos, H. Peiris, J. Peoples, W. J. Percival, A. A. Plazas, S. L. Reed, A. Refregier, A. K. Romer, A. Roodman, A. Ross, E. Rozo, E. S. Rykoff, I. Sadeh, M. Sako, C. Sanchez, E. Sanchez, B. Santiago, V. Scarpine, M. Schubnell, I. Sevilla-Noarbe, E. Sheldon, M. Smith, R. C. Smith, M. Soares-Santos, F. Sobreira, M. Soumagnac, E. Suchyta, M. Sullivan, M. Swanson, G. Tarle, J. Thaler, D. Thomas, R. C. Thomas, D. Tucker, J. D. Vieira, V. Vikram, A. R. Walker, R. H. Wechsler, J. Weller, W. Wester, L. Whiteway, H. Wilcox, B. Yanny, Y. Zhang, J. Zuntz

This overview article describes the legacy prospect and discovery potential of the Dark Energy Survey (DES) beyond cosmological studies, illustrating it with examples from the DES early data. DES is using a wide-field camera (DECam) on the 4m Blanco Telescope in Chile to image 5000 sq deg of the sky in five filters (grizY). By its completion the survey is expected to have generated a catalogue of 300 million galaxies with photometric redshifts and 100 million stars. Read More

The cumulative emission resulting from hadronic cosmic-ray interactions in star-forming galaxies (SFGs) has been proposed as the dominant contribution to the astrophysical neutrino flux at TeV to PeV energies reported by IceCube. The same particle interactions also inevitably create $\gamma$-ray emission that could be detectable as a component of the extragalactic $\gamma$-ray background (EGB), which is now measured with the Fermi-LAT in the energy range from 0.1 to 820 GeV. Read More

2015Sep
Authors: M. Ackermann1, M. Ajello2, A. Albert3, W. B. Atwood4, L. Baldini5, G. Barbiellini6, D. Bastieri7, K. Bechtol8, R. Bellazzini9, E. Bissaldi10, E. D. Bloom11, R. Bonino12, E. Bottacini13, T. J. Brandt14, J. Bregeon15, P. Bruel16, R. Buehler17, S. Buson18, G. A. Caliandro19, R. A. Cameron20, R. Caputo21, M. Caragiulo22, P. A. Caraveo23, J. M. Casandjian24, E. Cavazzuti25, C. Cecchi26, E. Charles27, A. Chekhtman28, G. Chiaro29, S. Ciprini30, J. Cohen-Tanugi31, J. Conrad32, S. Cutini33, F. D'Ammando34, A. de Angelis35, F. de Palma36, R. Desiante37, S. W. Digel38, L. Di Venere39, P. S. Drell40, C. Favuzzi41, S. J. Fegan42, W. B. Focke43, A. Franckowiak44, Y. Fukazawa45, S. Funk46, P. Fusco47, F. Gargano48, D. Gasparrini49, N. Giglietto50, F. Giordano51, M. Giroletti52, T. Glanzman53, G. Godfrey54, G. A. Gomez-Vargas55, I. A. Grenier56, S. Guiriec57, M. Gustafsson58, J. W. Hewitt59, A. B. Hill60, D. Horan61, T. E. Jeltema62, T. Jogler63, A. S. Johnson64, M. Kuss65, S. Larsson66, L. Latronico67, J. Li68, L. Li69, F. Longo70, F. Loparco71, M. N. Lovellette72, P. Lubrano73, S. Maldera74, D. Malyshev75, A. Manfreda76, M. Mayer77, M. N. Mazziotta78, P. F. Michelson79, T. Mizuno80, M. E. Monzani81, A. Morselli82, I. V. Moskalenko83, S. Murgia84, E. Nuss85, T. Ohsugi86, M. Orienti87, E. Orlando88, J. F. Ormes89, D. Paneque90, J. S. Perkins91, M. Pesce-Rollins92, V. Petrosian93, F. Piron94, G. Pivato95, T. A. Porter96, S. Rainò97, R. Rando98, M. Razzano99, A. Reimer100, O. Reimer101, M. Sánchez-Conde102, A. Schulz103, C. Sgró104, E. J. Siskind105, F. Spada106, G. Spandre107, P. Spinelli108, E. Storm109, H. Tajima110, H. Takahashi111, J. B. Thayer112, D. F. Torres113, G. Tosti114, E. Troja115, G. Vianello116, K. S. Wood117, M. Wood118, G. Zaharijas119, S. Zimmer120, A. Pinzke
Affiliations: 1The Fermi-LAT Collaboration, 2The Fermi-LAT Collaboration, 3The Fermi-LAT Collaboration, 4The Fermi-LAT Collaboration, 5The Fermi-LAT Collaboration, 6The Fermi-LAT Collaboration, 7The Fermi-LAT Collaboration, 8The Fermi-LAT Collaboration, 9The Fermi-LAT Collaboration, 10The Fermi-LAT Collaboration, 11The Fermi-LAT Collaboration, 12The Fermi-LAT Collaboration, 13The Fermi-LAT Collaboration, 14The Fermi-LAT Collaboration, 15The Fermi-LAT Collaboration, 16The Fermi-LAT Collaboration, 17The Fermi-LAT Collaboration, 18The Fermi-LAT Collaboration, 19The Fermi-LAT Collaboration, 20The Fermi-LAT Collaboration, 21The Fermi-LAT Collaboration, 22The Fermi-LAT Collaboration, 23The Fermi-LAT Collaboration, 24The Fermi-LAT Collaboration, 25The Fermi-LAT Collaboration, 26The Fermi-LAT Collaboration, 27The Fermi-LAT Collaboration, 28The Fermi-LAT Collaboration, 29The Fermi-LAT Collaboration, 30The Fermi-LAT Collaboration, 31The Fermi-LAT Collaboration, 32The Fermi-LAT Collaboration, 33The Fermi-LAT Collaboration, 34The Fermi-LAT Collaboration, 35The Fermi-LAT Collaboration, 36The Fermi-LAT Collaboration, 37The Fermi-LAT Collaboration, 38The Fermi-LAT Collaboration, 39The Fermi-LAT Collaboration, 40The Fermi-LAT Collaboration, 41The Fermi-LAT Collaboration, 42The Fermi-LAT Collaboration, 43The Fermi-LAT Collaboration, 44The Fermi-LAT Collaboration, 45The Fermi-LAT Collaboration, 46The Fermi-LAT Collaboration, 47The Fermi-LAT Collaboration, 48The Fermi-LAT Collaboration, 49The Fermi-LAT Collaboration, 50The Fermi-LAT Collaboration, 51The Fermi-LAT Collaboration, 52The Fermi-LAT Collaboration, 53The Fermi-LAT Collaboration, 54The Fermi-LAT Collaboration, 55The Fermi-LAT Collaboration, 56The Fermi-LAT Collaboration, 57The Fermi-LAT Collaboration, 58The Fermi-LAT Collaboration, 59The Fermi-LAT Collaboration, 60The Fermi-LAT Collaboration, 61The Fermi-LAT Collaboration, 62The Fermi-LAT Collaboration, 63The Fermi-LAT Collaboration, 64The Fermi-LAT Collaboration, 65The Fermi-LAT Collaboration, 66The Fermi-LAT Collaboration, 67The Fermi-LAT Collaboration, 68The Fermi-LAT Collaboration, 69The Fermi-LAT Collaboration, 70The Fermi-LAT Collaboration, 71The Fermi-LAT Collaboration, 72The Fermi-LAT Collaboration, 73The Fermi-LAT Collaboration, 74The Fermi-LAT Collaboration, 75The Fermi-LAT Collaboration, 76The Fermi-LAT Collaboration, 77The Fermi-LAT Collaboration, 78The Fermi-LAT Collaboration, 79The Fermi-LAT Collaboration, 80The Fermi-LAT Collaboration, 81The Fermi-LAT Collaboration, 82The Fermi-LAT Collaboration, 83The Fermi-LAT Collaboration, 84The Fermi-LAT Collaboration, 85The Fermi-LAT Collaboration, 86The Fermi-LAT Collaboration, 87The Fermi-LAT Collaboration, 88The Fermi-LAT Collaboration, 89The Fermi-LAT Collaboration, 90The Fermi-LAT Collaboration, 91The Fermi-LAT Collaboration, 92The Fermi-LAT Collaboration, 93The Fermi-LAT Collaboration, 94The Fermi-LAT Collaboration, 95The Fermi-LAT Collaboration, 96The Fermi-LAT Collaboration, 97The Fermi-LAT Collaboration, 98The Fermi-LAT Collaboration, 99The Fermi-LAT Collaboration, 100The Fermi-LAT Collaboration, 101The Fermi-LAT Collaboration, 102The Fermi-LAT Collaboration, 103The Fermi-LAT Collaboration, 104The Fermi-LAT Collaboration, 105The Fermi-LAT Collaboration, 106The Fermi-LAT Collaboration, 107The Fermi-LAT Collaboration, 108The Fermi-LAT Collaboration, 109The Fermi-LAT Collaboration, 110The Fermi-LAT Collaboration, 111The Fermi-LAT Collaboration, 112The Fermi-LAT Collaboration, 113The Fermi-LAT Collaboration, 114The Fermi-LAT Collaboration, 115The Fermi-LAT Collaboration, 116The Fermi-LAT Collaboration, 117The Fermi-LAT Collaboration, 118The Fermi-LAT Collaboration, 119The Fermi-LAT Collaboration, 120The Fermi-LAT Collaboration

Galaxy clusters are one of the prime sites to search for dark matter (DM) annihilation signals. Depending on the substructure of the DM halo of a galaxy cluster and the cross sections for DM annihilation channels, these signals might be detectable by the latest generation of $\gamma$-ray telescopes. Here we use three years of Fermi Large Area Telescope (LAT) data, which are the most suitable for searching for very extended emission in the vicinity of nearby Virgo galaxy cluster. Read More

We report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lower-confidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. Read More

The Dark Energy Survey (DES) is a 5000 sq. degree survey in the southern hemisphere, which is rapidly reducing the existing north-south asymmetry in the census of MW satellites and other stellar substructure. We use the first-year DES data down to previously unprobed photometric depths to search for stellar systems in the Galactic halo, therefore complementing the previous analysis of the same data carried out by our group earlier this year. Read More

For fifty years, cosmic-ray air showers have been detected by their radio emission. We present the first laboratory measurements that validate electrodynamics simulations used in air shower modeling. An experiment at SLAC provides a beam test of radio-frequency (RF) radiation from charged particle cascades in the presence of a magnetic field, a model system of a cosmic-ray air shower. Read More

The detection of high energy neutrinos ($10^{15}-10^{20}$ eV or $1-10^{5}$ PeV) is an important step toward understanding the most energetic cosmic accelerators and would enable tests of fundamental physics at energy scales that cannot easily be achieved on Earth. In this energy range, there are two expected populations of neutrinos: the astrophysical flux observed with IceCube at lower energies ($\sim1$ PeV) and the predicted cosmogenic flux at higher energies ($\sim10^{18}$ eV). Radio detector arrays such as RICE, ANITA, ARA, and ARIANNA exploit the Askaryan effect and the radio transparency of glacial ice, which together enable enormous volumes of ice to be monitored with sparse instrumentation. Read More

2015Apr
Affiliations: 1The DES Collaboration, 2The DES Collaboration, 3The DES Collaboration, 4The DES Collaboration, 5The DES Collaboration, 6The DES Collaboration, 7The DES Collaboration, 8The DES Collaboration, 9The DES Collaboration, 10The DES Collaboration, 11The DES Collaboration, 12The DES Collaboration, 13The DES Collaboration, 14The DES Collaboration, 15The DES Collaboration, 16The DES Collaboration, 17The DES Collaboration, 18The DES Collaboration, 19The DES Collaboration, 20The DES Collaboration, 21The DES Collaboration, 22The DES Collaboration, 23The DES Collaboration, 24The DES Collaboration, 25The DES Collaboration, 26The DES Collaboration, 27The DES Collaboration, 28The DES Collaboration, 29The DES Collaboration, 30The DES Collaboration, 31The DES Collaboration, 32The DES Collaboration, 33The DES Collaboration, 34The DES Collaboration, 35The DES Collaboration, 36The DES Collaboration, 37The DES Collaboration, 38The DES Collaboration, 39The DES Collaboration, 40The DES Collaboration, 41The DES Collaboration, 42The DES Collaboration, 43The DES Collaboration, 44The DES Collaboration, 45The DES Collaboration, 46The DES Collaboration, 47The DES Collaboration, 48The DES Collaboration, 49The DES Collaboration, 50The DES Collaboration, 51The DES Collaboration, 52The DES Collaboration, 53The DES Collaboration, 54The DES Collaboration, 55The DES Collaboration, 56The DES Collaboration, 57The DES Collaboration, 58The DES Collaboration, 59The DES Collaboration, 60The DES Collaboration, 61The DES Collaboration, 62The DES Collaboration, 63The DES Collaboration, 64The DES Collaboration, 65The DES Collaboration, 66The DES Collaboration, 67The DES Collaboration, 68The DES Collaboration, 69The DES Collaboration, 70The DES Collaboration, 71The DES Collaboration, 72The DES Collaboration

We present Magellan/M2FS, VLT/GIRAFFE, and Gemini South/GMOS spectroscopy of the newly discovered Milky Way satellite Reticulum II. Based on the spectra of 25 Ret II member stars selected from Dark Energy Survey imaging, we measure a mean heliocentric velocity of 62.8 +/- 0. Read More

We report the discovery of eight new Milky Way companions in ~1,800 deg^2 of optical imaging data collected during the first year of the Dark Energy Survey (DES). Each system is identified as a statistically significant over-density of individual stars consistent with the expected isochrone and luminosity function of an old and metal-poor stellar population. The objects span a wide range of absolute magnitudes (M_V from -2. Read More

2015Mar
Authors: The Fermi-LAT Collaboration, The DES Collaboration, :, A. Drlica-Wagner, A. Albert, K. Bechtol, M. Wood, L. Strigari, M. Sanchez-Conde, L. Baldini, R. Essig, J. Cohen-Tanugi, B. Anderson, R. Bellazzini, E. D. Bloom, R. Caputo, C. Cecchi, E. Charles, J. Chiang, A. de Angelis, S. Funk, P. Fusco, F. Gargano, N. Giglietto, F. Giordano, S. Guiriec, M. Gustafsson, M. Kuss, F. Loparco, P. Lubrano, N. Mirabal, T. Mizuno, A. Morselli, T. Ohsugi, E. Orlando, M. Persic, S. Raino, N. Sehgal, F. Spada, D. J. Suson, G. Zaharijas, S. Zimmer, T. Abbott, S. Allam, E. Balbinot, A. H. Bauer, A. Benoit-Levy, R. A. Bernstein, G. M. Bernstein, E. Bertin, D. Brooks, E. Buckley-Geer, D. L. Burke, A. Carnero Rosell, F. J. Castander, R. Covarrubias, C. B. D'Andrea, L. N. da Costa, D. L. DePoy, S. Desai, H. T. Diehl, C. E Cunha, T. F. Eifler, J. Estrada, A. E. Evrard, A. Fausti Neto, E. Fernandez, D. A. Finley, B. Flaugher, J. Frieman, E. Gaztanaga, D. Gerdes, D. Gruen, R. A. Gruendl, G. Gutierrez, K. Honscheid, B. Jain, D. James, T. Jeltema, S. Kent, R. Kron, K. Kuehn, N. Kuropatkin, O. Lahav, T. S. Li, E. Luque, M. A. G. Maia, M. Makler, M. March, J. Marshall, P. Martini, K. W. Merritt, C. Miller, R. Miquel, J. Mohr, E. Neilsen, B. Nord, R. Ogando, J. Peoples, D. Petravick, A. Pieres, A. A. Plazas, A. Queiroz, A. K. Romer, A. Roodman, E. S. Rykoff, M. Sako, E. Sanchez, B. Santiago, V. Scarpine, M. Schubnell, I. Sevilla, R. C. Smith, M. Soares-Santos, F. Sobreira, E. Suchyta, M. E. C. Swanson, G. Tarle, J. Thaler, D. Thomas, D. Tucker, A. Walker, R. H. Wechsler, W. Wester, P. Williams, B. Yanny, J. Zuntz

Due to their proximity, high dark-matter content, and apparent absence of non-thermal processes, Milky Way dwarf spheroidal satellite galaxies (dSphs) are excellent targets for the indirect detection of dark matter. Recently, eight new dSph candidates were discovered using the first year of data from the Dark Energy Survey (DES). We searched for gamma-ray emission coincident with the positions of these new objects in six years of Fermi Large Area Telescope data. Read More

2015Jan

We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~20 in canonical setups. Read More

The origin of the extragalactic $\gamma$-ray background (EGB) has been debated for some time. { The EGB comprises the $\gamma$-ray emission from resolved and unresolved extragalactic sources, such as blazars, star-forming galaxies and radio galaxies, as well as radiation from truly diffuse processes.} This letter focuses on the blazar source class, the most numerous detected population, and presents an updated luminosity function and spectral energy distribution model consistent with the blazar observations performed by the {\it Fermi} Large Area Telescope (LAT). Read More

We report on simultaneous observations of the local starburst system Arp 299 with NuSTAR and Chandra, which provides the first resolved images of this galaxy up to energies of ~ 45 keV. Fitting the 3-40 keV spectrum reveals a column density of $N_{\rm H}$ ~ 4 x10^{24} cm^{-2}, characteristic of a Compton-thick AGN, and a 10-30 keV luminosity of 1.2x 10^{43} ergs s^{-1}. Read More

2014Nov
Authors: The Fermi LAT Collaboration, A. A. Abdo, M. Ackermann, M. Ajello, A. Allafort, M. A. Amin, L. Baldini, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, R. D. Blandford, E. Bonamente, A. W. Borgland, J. Bregeon, M. Brigida, R. Buehler, D. Bulmash, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, E. Cavazzuti, C. Cecchi, E. Charles, C. C. Cheung, J. Chiang, G. Chiaro, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, R. H. D. Corbet, S. Cutini, F. D'Ammando, A. de Angelis, F. de Palma, C. D. Dermer, P. S. Drell, A. Drlica-Wagner, C. Favuzzi, J. Finke, W. B. Focke, Y. Fukazawa, P. Fusco, F. Gargano, D. Gasparrini, N. Gehrels, N. Giglietto, F. Giordano, M. Giroletti, T. Glanzman, I. A. Grenier, J. E. Grove, S. Guiriec, D. Hadasch, M. Hayashida, E. Hays, R. E. Hughes, Y. Inoue, M. S. Jackson, T. Jogler, G. Jòhannesson, A. S. Johnson, T. Kamae, J. Knödlseder, M. Kuss, J. Lande, S. Larsson, L. Latronico, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, G. M. Madejski, M. N. Mazziotta, J. Mehault, P. F. Michelson, T. Mizuno, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, R. Nemmen, E. Nuss, M. Ohno, T. Ohsugi, D. Paneque, J. S. Perkins, M. Pesce-Rollins, F. Piron, G. Pivato, T. A. Porter, S. Rainò, R. Rando, M. Razzano, A. Reimer, O. Reimer, L. C. Reyes, S. Ritz, C. Romoli, M. Roth, P. M. Saz Parkinson, C. Sgrò, E. J. Siskind, G. Spandre, P. Spinelli, H. Takahashi, Y. Takeuchi, T. Tanaka, J. G. Thayer, J. B. Thayer, D. J. Thompson, L. Tibaldo, M. Tinivella, D. F. Torres, G. Tosti, E. Troja, V. Tronconi, T. L. Usher, J. Vandenbroucke, V. Vasileiou, G. Vianello, V. Vitale, A. P. Waite, M. Werner, B. L. Winer, K. S. Wood

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope routinely detects the highly dust-absorbed, reddened, and MeV-peaked flat spectrum radio quasar PKS 1830-211 (z=2.507). Its apparent isotropic gamma-ray luminosity (E>100 MeV) averaged over $\sim$ 3 years of observations and peaking on 2010 October 14/15 at 2. Read More

Prior to the launch of NuSTAR, it was not feasible to spatially resolve the hard (E > 10 keV) emission from galaxies beyond the Local Group. The combined NuSTAR dataset, comprised of three ~165 ks observations, allows spatial characterization of the hard X-ray emission in the galaxy NGC 253 for the first time. As a follow up to our initial study of its nuclear region, we present the first results concerning the full galaxy from simultaneous NuSTAR, Chandra, and VLBA monitoring of the local starburst galaxy NGC 253. Read More

2014Oct
Authors: The Fermi LAT collaboration, M. Ackermann, M. Ajello, A. Albert, W. B. Atwood, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, E. Bissaldi, R. D. Blandford, E. D. Bloom, E. Bottacini, T. J. Brandt, J. Bregeon, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, M. Caragiulo, P. A. Caraveo, E. Cavazzuti, C. Cecchi, E. Charles, A. Chekhtman, J. Chiang, G. Chiaro, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, A. Cuoco, S. Cutini, F. D'Ammando, A. de Angelis, F. de Palma, C. D. Dermer, S. W. Digel, E. do Couto e Silva, P. S. Drell, C. Favuzzi, E. C. Ferrara, W. B. Focke, A. Franckowiak, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, D. Gasparrini, S. Germani, N. Giglietto, P. Giommi, F. Giordano, M. Giroletti, G. Godfrey, G. A. Gomez-Vargas, I. A. Grenier, S. Guiriec, M. Gustafsson, D. Hadasch, K. Hayashi, E. Hays, J. W. Hewitt, P. Ippoliti, T. Jogler, G. Jóhannesson, A. S. Johnson, W. N. Johnson, T. Kamae, J. Kataoka, J. Knödlseder, M. Kuss, S. Larsson, L. Latronico, J. Li, L. Li, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, G. M. Madejski, A. Manfreda, F. Massaro, M. Mayer, M. N. Mazziotta, J. E. McEnery, P. F. Michelson, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, R. Nemmen, E. Nuss, T. Ohsugi, N. Omodei, E. Orlando, J. F. Ormes, D. Paneque, J. H. Panetta, J. S. Perkins, M. Pesce-Rollins, F. Piron, G. Pivato, T. A. Porter, S. Rainò, R. Rando, M. Razzano, S. Razzaque, A. Reimer, O. Reimer, T. Reposeur, S. Ritz, R. W. Romani, M. Sánchez-Conde, M. Schaal, A. Schulz, C. Sgrò, E. J. Siskind, G. Spandre, P. Spinelli, A. W. Strong, D. J. Suson, H. Takahashi, J. G. Thayer, J. B. Thayer, L. Tibaldo, M. Tinivella, D. F. Torres, G. Tosti, E. Troja, Y. Uchiyama, G. Vianello, M. Werner, B. L. Winer, K. S. Wood, M. Wood, G. Zaharijas, S. Zimmer

The {\gamma}-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky emission component commonly called the isotropic diffuse {\gamma}-ray background (IGRB). The IGRB comprises all extragalactic emissions too faint or too diffuse to be resolved in a given survey, as well as any residual Galactic foregrounds that are approximately isotropic. The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV. Read More

We measure the weak-lensing masses and galaxy distributions of four massive galaxy clusters observed during the Science Verification phase of the Dark Energy Survey. This pathfinder study is meant to 1) validate the DECam imager for the task of measuring weak-lensing shapes, and 2) utilize DECam's large field of view to map out the clusters and their environments over 90 arcmin. We conduct a series of rigorous tests on astrometry, photometry, image quality, PSF modeling, and shear measurement accuracy to single out flaws in the data and also to identify the optimal data processing steps and parameters. Read More

2014Mar
Authors: Fermi-LAT Collaboration, :, M. Ackermann, M. Ajello, A. Albert, A. Allafort, L. Baldini, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, R. D. Blandford, E. D. Bloom, E. Bonamente, E. Bottacini, A. Bouvier, T. J. Brandt, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, C. Cecchi, E. Charles, R. C. G. Chaves, A. Chekhtman, J. Chiang, G. Chiaro, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, S. Cutini, M. Dalton, F. D'Ammando, A. de Angelis, F. de Palma, C. D. Dermer, S. W. Digel, L. Di Venere, E. do Couto e Silva, P. S. Drell, A. Drlica-Wagner, C. Favuzzi, S. J. Fegan, E. C. Ferrara, W. B. Focke, A. Franckowiak, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, D. Gasparrini, S. Germani, N. Giglietto, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, G. A. Gomez-Vargas, I. A. Grenier, J. E. Grove, S. Guiriec, M. Gustafsson, D. Hadasch, Y. Hanabata, A. K. Harding, M. Hayashida, K. Hayashi, J. W. Hewitt, D. Horan, X. Hou, R. E. Hughes, Y. Inoue, M. S. Jackson, T. Jogler, G. Jóhannesson, A. S. Johnson, T. Kamae, T. Kawano, J. Knödlseder, M. Kuss, J. Lande, S. Larsson, L. Latronico, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, M. Mayer, M. N. Mazziotta, J. E. McEnery, J. Mehault, P. F. Michelson, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, R. Nemmen, E. Nuss, T. Ohsugi, A. Okumura, M. Orienti, E. Orlando, J. F. Ormes, D. Paneque, J. H. Panetta, J. S. Perkins, M. Pesce-Rollins, F. Piron, G. Pivato, T. A. Porter, S. Rainò, R. Rando, M. Razzano, S. Razzaque, A. Reimer, O. Reimer, S. Ritz, M. Roth, M. Schaal, A. Schulz, C. Sgrò, E. J. Siskind, G. Spandre, P. Spinelli, A. W. Strong, H. Takahashi, Y. Takeuchi, J. G. Thayer, J. B. Thayer, D. J. Thompson, L. Tibaldo, M. Tinivella, D. F. Torres, G. Tosti, E. Troja, V. Tronconi, T. L. Usher, J. Vandenbroucke, V. Vasileiou, G. Vianello, V. Vitale, M. Werner, B. L. Winer, K. S. Wood, M. Wood, Z. Yang

Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly-discovered features may offer a clue to the origin of high-energy CRs. We use the ${\it Fermi}$ Large Area Telescope observations of the $\gamma$-ray emission from the Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range $\sim 90~$GeV-$6~$TeV (derived from a photon energy range $15~$GeV-$1~$TeV). Read More

We report the discovery of gamma-ray emission from the Circinus galaxy using the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope. Circinus is a nearby (~4 Mpc) starburst with a heavily obscured Seyfert-type active nucleus, bipolar radio lobes perpendicular to the spiral disk, and kpc-scale jet-like structures. Our analysis of 0. Read More

2013Oct
Authors: The Fermi-LAT Collaboration, :, M. Ackermann, A. Albert, B. Anderson, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, E. Bissaldi, E. D. Bloom, E. Bonamente, A. Bouvier, T. J. Brandt, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, M. Caragiulo, P. A. Caraveo, C. Cecchi, E. Charles, A. Chekhtman, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, F. D'Ammando, A. de Angelis, C. D. Dermer, S. W. Digel, E. do Couto e Silva, P. S. Drell, A. Drlica-Wagner, R. Essig, C. Favuzzi, E. C. Ferrara, A. Franckowiak, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, D. Gasparrini, N. Giglietto, M. Giroletti, G. Godfrey, G. A. Gomez-Vargas, I. A. Grenier, S. Guiriec, M. Gustafsson, M. Hayashida, E. Hays, J. Hewitt, R. E. Hughes, T. Jogler, T. Kamae, J. Knödlseder, D. Kocevski, M. Kuss, . Larsson, L. Latronico, M. Llena Garde, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, G. Martinez, M. Mayer, M. N. Mazziotta, P. F. Michelson, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, R. Nemmen, E. Nuss, T. Ohsugi, E. Orlando, J. F. Ormes, J. S. Perkins, F. Piron, G. Pivato, T. A. Porter, S. Rainò, R. Rando, M. Razzano, S. Razzaque, A. Reimer, O. Reimer, S. Ritz, M. Sànchez-Conde, N. Sehgal, C. Sgrò, E. J. Siskind, P. Spinelli, L. Strigari, D. J. Suson, H. Tajima, H. Takahashi, J. B. Thayer, L. Tibaldo, M. Tinivella, D. F. Torres, Y. Uchiyama, T. L. Usher, J. Vandenbroucke, G. Vianello, V. Vitale, M. Werner, B. L. Winer, K. S. Wood, M. Wood, G. Zaharijas, S. Zimmer

The dwarf spheroidal satellite galaxies of the Milky Way are some of the most dark-matter-dominated objects known. Due to their proximity, high dark matter content, and lack of astrophysical backgrounds, dwarf spheroidal galaxies are widely considered to be among the most promising targets for the indirect detection of dark matter via gamma rays. Here we report on gamma-ray observations of 25 Milky Way dwarf spheroidal satellite galaxies based on 4 years of Fermi Large Area Telescope (LAT) data. Read More

Among the most stringent constraints on the dark matter annihilation cross section are those derived from observations of dwarf galaxies by the Fermi Gamma-Ray Space Telescope. As current (e.g. Read More

2013Aug
Authors: M. Ackermann1, M. Ajello2, A. Albert3, A. Allafort4, W. B. Atwood5, L. Baldini6, J. Ballet7, G. Barbiellini8, D. Bastieri9, K. Bechtol10, R. Bellazzini11, E. D. Bloom12, E. Bonamente13, E. Bottacini14, T. J. Brandt15, J. Bregeon16, M. Brigida17, P. Bruel18, R. Buehler19, S. Buson20, G. A. Caliandro21, R. A. Cameron22, P. A. Caraveo23, E. Cavazzuti24, R. C. G. Chaves25, J. Chiang26, G. Chiaro27, S. Ciprini28, R. Claus29, J. Cohen-Tanugi30, J. Conrad31, F. D'Ammando32, A. de Angelis33, F. de Palma34, C. D. Dermer35, S. W. Digel36, P. S. Drell37, A. Drlica-Wagner38, C. Favuzzi39, A. Franckowiak40, S. Funk41, P. Fusco42, F. Gargano43, D. Gasparrini44, S. Germani45, N. Giglietto46, F. Giordano47, M. Giroletti48, G. Godfrey49, G. A. Gomez-Vargas50, I. A. Grenier51, S. Guiriec52, M. Gustafsson53, D. Hadasch54, M. Hayashida55, J. Hewitt56, R. E. Hughes57, T. E. Jeltema58, G. Jóhannesson59, A. S. Johnson60, T. Kamae61, J. Kataoka62, J. Knödlseder63, M. Kuss64, J. Lande65, S. Larsson66, L. Latronico67, M. Llena Garde68, F. Longo69, F. Loparco70, M. N. Lovellette71, P. Lubrano72, M. Mayer73, M. N. Mazziotta74, J. E. McEnery75, P. F. Michelson76, W. Mitthumsiri77, T. Mizuno78, M. E. Monzani79, A. Morselli80, I. V. Moskalenko81, S. Murgia82, R. Nemmen83, E. Nuss84, T. Ohsugi85, M. Orienti86, E. Orlando87, J. F. Ormes88, J. S. Perkins89, M. Pesce-Rollins90, F. Piron91, G. Pivato92, S. Rainò93, R. Rando94, M. Razzano95, S. Razzaque96, A. Reimer97, O. Reimer98, J. Ruan99, M. Sánchez-Conde100, A. Schulz101, C. Sgrò102, E. J. Siskind103, G. Spandre104, P. Spinelli105, E. Storm106, A. W. Strong107, D. J. Suson108, H. Takahashi109, J. G. Thayer110, J. B. Thayer111, D. J. Thompson112, L. Tibaldo113, M. Tinivella114, D. F. Torres115, E. Troja116, Y. Uchiyama117, T. L. Usher118, J. Vandenbroucke119, G. Vianello120, V. Vitale121, B. L. Winer122, K. S. Wood123, S. Zimmer124, C. Pfrommer, A. Pinzke
Affiliations: 1Fermi-LAT Collaboration, 2Fermi-LAT Collaboration, 3Fermi-LAT Collaboration, 4Fermi-LAT Collaboration, 5Fermi-LAT Collaboration, 6Fermi-LAT Collaboration, 7Fermi-LAT Collaboration, 8Fermi-LAT Collaboration, 9Fermi-LAT Collaboration, 10Fermi-LAT Collaboration, 11Fermi-LAT Collaboration, 12Fermi-LAT Collaboration, 13Fermi-LAT Collaboration, 14Fermi-LAT Collaboration, 15Fermi-LAT Collaboration, 16Fermi-LAT Collaboration, 17Fermi-LAT Collaboration, 18Fermi-LAT Collaboration, 19Fermi-LAT Collaboration, 20Fermi-LAT Collaboration, 21Fermi-LAT Collaboration, 22Fermi-LAT Collaboration, 23Fermi-LAT Collaboration, 24Fermi-LAT Collaboration, 25Fermi-LAT Collaboration, 26Fermi-LAT Collaboration, 27Fermi-LAT Collaboration, 28Fermi-LAT Collaboration, 29Fermi-LAT Collaboration, 30Fermi-LAT Collaboration, 31Fermi-LAT Collaboration, 32Fermi-LAT Collaboration, 33Fermi-LAT Collaboration, 34Fermi-LAT Collaboration, 35Fermi-LAT Collaboration, 36Fermi-LAT Collaboration, 37Fermi-LAT Collaboration, 38Fermi-LAT Collaboration, 39Fermi-LAT Collaboration, 40Fermi-LAT Collaboration, 41Fermi-LAT Collaboration, 42Fermi-LAT Collaboration, 43Fermi-LAT Collaboration, 44Fermi-LAT Collaboration, 45Fermi-LAT Collaboration, 46Fermi-LAT Collaboration, 47Fermi-LAT Collaboration, 48Fermi-LAT Collaboration, 49Fermi-LAT Collaboration, 50Fermi-LAT Collaboration, 51Fermi-LAT Collaboration, 52Fermi-LAT Collaboration, 53Fermi-LAT Collaboration, 54Fermi-LAT Collaboration, 55Fermi-LAT Collaboration, 56Fermi-LAT Collaboration, 57Fermi-LAT Collaboration, 58Fermi-LAT Collaboration, 59Fermi-LAT Collaboration, 60Fermi-LAT Collaboration, 61Fermi-LAT Collaboration, 62Fermi-LAT Collaboration, 63Fermi-LAT Collaboration, 64Fermi-LAT Collaboration, 65Fermi-LAT Collaboration, 66Fermi-LAT Collaboration, 67Fermi-LAT Collaboration, 68Fermi-LAT Collaboration, 69Fermi-LAT Collaboration, 70Fermi-LAT Collaboration, 71Fermi-LAT Collaboration, 72Fermi-LAT Collaboration, 73Fermi-LAT Collaboration, 74Fermi-LAT Collaboration, 75Fermi-LAT Collaboration, 76Fermi-LAT Collaboration, 77Fermi-LAT Collaboration, 78Fermi-LAT Collaboration, 79Fermi-LAT Collaboration, 80Fermi-LAT Collaboration, 81Fermi-LAT Collaboration, 82Fermi-LAT Collaboration, 83Fermi-LAT Collaboration, 84Fermi-LAT Collaboration, 85Fermi-LAT Collaboration, 86Fermi-LAT Collaboration, 87Fermi-LAT Collaboration, 88Fermi-LAT Collaboration, 89Fermi-LAT Collaboration, 90Fermi-LAT Collaboration, 91Fermi-LAT Collaboration, 92Fermi-LAT Collaboration, 93Fermi-LAT Collaboration, 94Fermi-LAT Collaboration, 95Fermi-LAT Collaboration, 96Fermi-LAT Collaboration, 97Fermi-LAT Collaboration, 98Fermi-LAT Collaboration, 99Fermi-LAT Collaboration, 100Fermi-LAT Collaboration, 101Fermi-LAT Collaboration, 102Fermi-LAT Collaboration, 103Fermi-LAT Collaboration, 104Fermi-LAT Collaboration, 105Fermi-LAT Collaboration, 106Fermi-LAT Collaboration, 107Fermi-LAT Collaboration, 108Fermi-LAT Collaboration, 109Fermi-LAT Collaboration, 110Fermi-LAT Collaboration, 111Fermi-LAT Collaboration, 112Fermi-LAT Collaboration, 113Fermi-LAT Collaboration, 114Fermi-LAT Collaboration, 115Fermi-LAT Collaboration, 116Fermi-LAT Collaboration, 117Fermi-LAT Collaboration, 118Fermi-LAT Collaboration, 119Fermi-LAT Collaboration, 120Fermi-LAT Collaboration, 121Fermi-LAT Collaboration, 122Fermi-LAT Collaboration, 123Fermi-LAT Collaboration, 124Fermi-LAT Collaboration

Current theories predict relativistic hadronic particle populations in clusters of galaxies in addition to the already observed relativistic leptons. In these scenarios hadronic interactions give rise to neutral pions which decay into $\gamma$ rays, that are potentially observable with the Large Area Telescope (LAT) on board the Fermi space telescope. We present a joint likelihood analysis searching for spatially extended $\gamma$-ray emission at the locations of 50 galaxy clusters in 4 years of Fermi-LAT data under the assumption of the universal cosmic-ray model proposed by Pinzke & Pfrommer (2010). Read More

2013Jul
Authors: The CTA Consortium, :, O. Abril, B. S. Acharya, M. Actis, G. Agnetta, J. A. Aguilar, F. Aharonian, M. Ajello, A. Akhperjanian, M. Alcubierre, J. Aleksic, R. Alfaro, E. Aliu, A. J. Allafort, D. Allan, I. Allekotte, R. Aloisio, E. Amato, G. Ambrosi, M. Ambrosio, J. Anderson, E. O. Angüner, L. A. Antonelli, V. Antonuccio, M. Antonucci, P. Antoranz, A. Aravantinos, A. Argan, T. Arlen, C. Aramo, T. Armstrong, H. Arnaldi, L. Arrabito, K. Asano, T. Ashton, H. G. Asorey, T. Aune, Y. Awane, H. Baba, A. Babic, N. Baby, J. Bähr, A. Bais, C. Baixeras, S. Bajtlik, M. Balbo, D. Balis, C. Balkowski, J. Ballet, A. Bamba, R. Bandiera, A. Barber, C. Barbier, M. Barceló, A. Barnacka, J. Barnstedt, U. Barres de Almeida, J. A. Barrio, A. Basili, S. Basso, D. Bastieri, C. Bauer, A. Baushev, U. Becciani, J. Becerra, J. Becerra, Y. Becherini, K. C. Bechtol, J. Becker Tjus, V. Beckmann, W. Bednarek, B. Behera, M. Belluso, W. Benbow, J. Berdugo, D. Berge, K. Berger, F. Bernard, T. Bernardino, K. Bernlöhr, B. Bertucci, N. Bhat, S. Bhattacharyya, B. Biasuzzi, C. Bigongiari, A. Biland, S. Billotta, T. Bird, E. Birsin, E. Bissaldi, J. Biteau, M. Bitossi, S. Blake, O. Blanch Bigas, P. Blasi, A. Bobkov, V. Boccone, M. Böttcher, L. Bogacz, J. Bogart, M. Bogdan, C. Boisson, J. Boix Gargallo, J. Bolmont, G. Bonanno, A. Bonardi, T. Bonev, P. Bonifacio, G. Bonnoli, P. Bordas, A. Borgland, J. Borkowski, R. Bose, O. Botner, A. Bottani, L. Bouchet, M. Bourgeat, C. Boutonnet, A. Bouvier, S. Brau-Nogué, I. Braun, T. Bretz, M. Briggs, M. Brigida, T. Bringmann, R. Britto, P. Brook, P. Brun, L. Brunetti, P. Bruno, N. Bucciantini, T. Buanes, J. Buckley, R. Bühler, V. Bugaev, A. Bulgarelli, T. Bulik, G. Busetto, S. Buson, K. Byrum, M. Cailles, R. Cameron, J. Camprecios, R. Canestrari, S. Cantu, M. Capalbi, P. Caraveo, E. Carmona, A. Carosi, R. Carosi, J. Carr, J. Carter, P. -H. Carton, R. Caruso, S. Casanova, E. Cascone, M. Casiraghi, A. Castellina, O. Catalano, S. Cavazzani, S. Cazaux, P. Cerchiara, M. Cerruti, E. Chabanne, P. Chadwick, C. Champion, R. Chaves, P. Cheimets, A. Chen, J. Chiang, L. Chiappetti, M. Chikawa, V. R. Chitnis, F. Chollet, A. Christof, J. Chudoba, M. Cieślar, A. Cillis, M. Cilmo, A. Codino, J. Cohen-Tanugi, S. Colafrancesco, P. Colin, J. Colome, S. Colonges, M. Compin, P. Conconi, V. Conforti, V. Connaughton, J. Conrad, J. L. Contreras, P. Coppi, J. Coridian, P. Corona, D. Corti, J. Cortina, L. Cossio, A. Costa, H. Costantini, G. Cotter, B. Courty, S. Couturier, S. Covino, G. Crimi, S. J. Criswell, J. Croston, G. Cusumano, M. Dafonseca, O. Dale, M. Daniel, J. Darling, I. Davids, F. Dazzi, A. de Angelis, V. De Caprio, F. De Frondat, E. M. de Gouveia Dal Pino, I. de la Calle, G. A. De La Vega, R. de los Reyes Lopez, B. de Lotto, A. De Luca, M. de Naurois, Y. de Oliveira, E. de Oña Wilhelmi, F. de Palma, V. de Souza, G. Decerprit, G. Decock, C. Deil, E. Delagnes, G. Deleglise, C. Delgado, D. della Volpe, P. Demange, G. Depaola, A. Dettlaff, T. Di Girolamo, C. Di Giulio, A. Di Paola, F. Di Pierro, G. di Sciascio, C. Díaz, J. Dick, R. Dickherber, H. Dickinson, V. Diez-Blanco, S. Digel, D. Dimitrov, G. Disset, A. Djannati-Ataï, M. Doert, M. Dohmke, W. Domainko, D. Dominis Prester, A. Donat, D. Dorner, M. Doro, J. -L. Dournaux, G. Drake, D. Dravins, L. Drury, F. Dubois, R. Dubois, G. Dubus, C. Dufour, D. Dumas, J. Dumm, D. Durand, V. Dwarkadas, J. Dyks, M. Dyrda, J. Ebr, E. Edy, K. Egberts, P. Eger, S. Einecke, C. Eleftheriadis, S. Elles, D. Emmanoulopoulos, D. Engelhaupt, R. Enomoto, J. -P. Ernenwein, M. Errando, A. Etchegoyen, P. A. Evans, A. Falcone, A. Faltenbacher, D. Fantinel, K. Farakos, C. Farnier, E. Farrell, G. Fasola, B. W. Favill, E. Fede, S. Federici, S. Fegan, F. Feinstein, D. Ferenc, P. Ferrando, M. Fesquet, P. Fetfatzis, A. Fiasson, E. Fillin-Martino, D. Fink, C. Finley, J. P. Finley, M. Fiorini, R. Firpo Curcoll, E. Flandrini, H. Fleischhack, H. Flores, D. Florin, W. Focke, C. Föhr, E. Fokitis, L. Font, G. Fontaine, M. Fornasa, A. Förster, L. Fortson, N. Fouque, A. Franckowiak, F. J. Franco, A. Frankowski, C. Fransson, G. W. Fraser, R. Frei, L. Fresnillo, C. Fruck, D. Fugazza, Y. Fujita, Y. Fukazawa, Y. Fukui, S. Funk, W. Gäbele, S. Gabici, R. Gabriele, A. Gadola, N. Galante, D. Gall, Y. Gallant, J. Gámez-García, M. Garczarczyk, B. García, R. Garcia López, D. Gardiol, F. Gargano, D. Garrido, L. Garrido, D. Gascon, M. Gaug, J. Gaweda, L. Gebremedhin, N. Geffroy, L. Gerard, A. Ghedina, M. Ghigo, P. Ghislain, E. Giannakaki, F. Gianotti, S. Giarrusso, G. Giavitto, B. Giebels, N. Giglietto, V. Gika, M. Giomi, P. Giommi, F. Giordano, N. Girard, E. Giro, A. Giuliani, T. Glanzman, J. -F. Glicenstein, N. Godinovic, V. Golev, M. Gomez Berisso, J. Gómez-Ortega, M. M. Gonzalez, A. González, F. González, A. González Muñoz, K. S. Gothe, T. Grabarczyk, M. Gougerot, R. Graciani, P. Grandi, F. Grañena, J. Granot, G. Grasseau, R. Gredig, A. Green, T. Greenshaw, T. Grégoire, A. Grillo, O. Grimm, M. -H. Grondin, J. Grube, M. Grudzinska, V. Gruev, S. Grünewald, J. Grygorczuk, V. Guarino, S. Gunji, G. Gyuk, D. Hadasch, A. Hagedorn, R. Hagiwara, J. Hahn, N. Hakansson, A. Hallgren, N. Hamer Heras, S. Hara, M. J. Hardcastle, D. Harezlak, J. Harris, T. Hassan, K. Hatanaka, T. Haubold, A. Haupt, T. Hayakawa, M. Hayashida, R. Heller, F. Henault, G. Henri, G. Hermann, R. Hermel, A. Herrero, O. Hervet, N. Hidaka, J. A. Hinton, K. Hirotani, D. Hoffmann, W. Hofmann, P. Hofverberg, J. Holder, J. R. Hörandel, D. Horns, D. Horville, J. Houles, M. Hrabovsky, D. Hrupec, H. Huan, B. Huber, J. -M. Huet, G. Hughes, T. B. Humensky, J. Huovelin, J. -F. Huppert, A. Ibarra, D. Ikawa, J. M. Illa, D. Impiombato, S. Incorvaia, S. Inoue, Y. Inoue, F. Iocco, K. Ioka, G. L. Israel, C. Jablonski, A. Jacholkowska, J. Jacquemier, M. Jamrozy, M. Janiak, P. Jean, C. Jeanney, J. J. Jimenez, T. Jogler, C. Johnson, T. Johnson, L. Journet, C. Juffroy, I. Jung, P. Kaaret, S. Kabuki, M. Kagaya, J. Kakuwa, C. Kalkuhl, R. Kankanyan, A. Karastergiou, K. Kärcher, M. Karczewski, S. Karkar, J. Kasperek, D. Kastana, H. Katagiri, J. Kataoka, K. Katarzyński, U. Katz, N. Kawanaka, D. Kazanas, N. Kelley-Hoskins, B. Kellner-Leidel, H. Kelly, E. Kendziorra, B. Khélifi, D. B. Kieda, T. Kifune, T. Kihm, T. Kishimoto, K. Kitamoto, W. Kluźniak, C. Knapic, J. Knapp, J. Knödlseder, F. Köck, J. Kocot, K. Kodani, J. -H. Köhne, K. Kohri, K. Kokkotas, D. Kolitzus, N. Komin, I. Kominis, Y. Konno, H. Köppel, P. Korohoda, K. Kosack, G. Koss, R. Kossakowski, R. Koul, G. Kowal, S. Koyama, J. Kozioł, T. Krähenbühl, J. Krause, H. Krawzcynski, F. Krennrich, A. Krepps, A. Kretzschmann, R. Krobot, P. Krueger, H. Kubo, V. A. Kudryavtsev, J. Kushida, A. Kuznetsov, A. La Barbera, N. La Palombara, V. La Parola, G. La Rosa, K. Lacombe, G. Lamanna, J. Lande, D. Languignon, J. S. Lapington, P. Laporte, B. Laurent, C. Lavalley, T. Le Flour, A. Le Padellec, S. -H. Lee, W. H. Lee, J. -P. Lefèvre, H. Leich, M. A. Leigui de Oliveira, D. Lelas, J. -P. Lenain, R. Leoni, D. J. Leopold, T. Lerch, L. Lessio, G. Leto, B. Lieunard, S. Lieunard, R. Lindemann, E. Lindfors, A. Liolios, A. Lipniacka, H. Lockart, T. Lohse, S. Lombardi, F. Longo, A. Lopatin, M. Lopez, R. López-Coto, A. López-Oramas, A. Lorca, E. Lorenz, F. Louis, P. Lubinski, F. Lucarelli, H. Lüdecke, J. Ludwin, P. L. Luque-Escamilla, W. Lustermann, O. Luz, E. Lyard, M. C. Maccarone, T. J. Maccarone, G. M. Madejski, A. Madhavan, M. Mahabir, G. Maier, P. Majumdar, G. Malaguti, G. Malaspina, S. Maltezos, A. Manalaysay, A. Mancilla, D. Mandat, G. Maneva, A. Mangano, P. Manigot, K. Mannheim, I. Manthos, N. Maragos, A. Marcowith, M. Mariotti, M. Marisaldi, S. Markoff, A. Marszałek, C. Martens, J. Martí, J. -M. Martin, P. Martin, G. Martínez, F. Martínez, M. Martínez, F. Massaro, A. Masserot, A. Mastichiadis, A. Mathieu, H. Matsumoto, F. Mattana, S. Mattiazzo, A. Maurer, G. Maurin, S. Maxfield, J. Maya, D. Mazin, L. Mc Comb, A. McCann, N. McCubbin, I. McHardy, R. McKay, K. Meagher, C. Medina, C. Melioli, D. Melkumyan, D. Melo, S. Mereghetti, P. Mertsch, M. Meucci, M. Meyer, J. Michałowski, P. Micolon, A. Mihailidis, T. Mineo, M. Minuti, N. Mirabal, F. Mirabel, J. M. Miranda, R. Mirzoyan, A. Mistò, T. Mizuno, B. Moal, R. Moderski, I. Mognet, E. Molinari, M. Molinaro, T. Montaruli, C. Monte, I. Monteiro, P. Moore, A. Moralejo Olaizola, M. Mordalska, C. Morello, K. Mori, G. Morlino, A. Morselli, F. Mottez, Y. Moudden, E. Moulin, I. Mrusek, R. Mukherjee, P. Munar-Adrover, H. Muraishi, K. Murase, A. StJ. Murphy, S. Nagataki, T. Naito, D. Nakajima, T. Nakamori, K. Nakayama, C. Naumann, D. Naumann, M. Naumann-Godo, P. Nayman, D. Nedbal, D. Neise, L. Nellen, A. Neronov, V. Neustroev, N. Neyroud, L. Nicastro, J. Nicolau-Kukliński, A. Niedźwiecki, J. Niemiec, D. Nieto, A. Nikolaidis, K. Nishijima, K. -I. Nishikawa, K. Noda, S. Nolan, R. Northrop, D. Nosek, N. Nowak, A. Nozato, L. Oakes, P. T. O'Brien, Y. Ohira, M. Ohishi, S. Ohm, H. Ohoka, T. Okuda, A. Okumura, J. -F. Olive, R. A. Ong, R. Orito, M. Orr, J. P. Osborne, M. Ostrowski, L. A. Otero, N. Otte, E. Ovcharov, I. Oya, A. Ozieblo, L. Padilla, I. Pagano, S. Paiano, D. Paillot, A. Paizis, S. Palanque, M. Palatka, J. Pallota, M. Palatiello, K. Panagiotidis, J. -L. Panazol, D. Paneque, M. Panter, M. R. Panzera, R. Paoletti, A. Papayannis, G. Papyan, J. M. Paredes, G. Pareschi, J. -M. Parraud, D. Parsons, G. Pauletta, M. Paz Arribas, M. Pech, G. Pedaletti, V. Pelassa, D. Pelat, M. d. C. Perez, M. Persic, P. -O. Petrucci, B. Peyaud, A. Pichel, D. Pieloth, E. Pierre, S. Pita, G. Pivato, F. Pizzolato, M. Platino, Ł. Platos, R. Platzer, S. Podkladkin, L. Pogosyan, M. Pohl, G. Pojmanski, J. D. Ponz, W. Potter, J. Poutanen, E. Prandini, J. Prast, R. Preece, F. Profeti, H. Prokoph, M. Prouza, M. Proyetti, I. Puerto-Giménez, G. Pühlhofer, I. Puljak, M. Punch, R. Pyzioł, E. J. Quel, J. Quesada, J. Quinn, A. Quirrenbach, E. Racero, S. Rainò, P. J. Rajda, M. Rameez, P. Ramon, R. Rando, R. C. Rannot, M. Rataj, M. Raue, D. Ravignani, P. Reardon, O. Reimann, A. Reimer, O. Reimer, K. Reitberger, M. Renaud, S. Renner, B. Reville, W. Rhode, M. Ribó, M. Ribordy, G. Richards, M. G. Richer, J. Rico, J. Ridky, F. Rieger, P. Ringegni, J. Ripken, P. R. Ristori, A. Rivière, S. Rivoire, L. Rob, G. Rodeghiero, U. Roeser, R. Rohlfs, G. Rojas, P. Romano, W. Romaszkan, G. E. Romero, S. R. Rosen, S. Rosier Lees, D. Ross, G. Rouaix, J. Rousselle, S. Rousselle, A. C. Rovero, F. Roy, S. Royer, B. Rudak, C. Rulten, M. Rupiński, F. Russo, F. Ryde, O. Saavedra, B. Sacco, E. O. Saemann, A. Saggion, V. Sahakian, K. Saito, T. Saito, Y. Saito, N. Sakaki, R. Sakonaka, A. Salini, F. Sanchez, M. Sanchez-Conde, A. Sandoval, H. Sandaker, E. Sant'Ambrogio, A. Santangelo, E. M. Santos, A. Sanuy, L. Sapozhnikov, S. Sarkar, N. Sartore, H. Sasaki, K. Satalecka, M. Sawada, V. Scalzotto, V. Scapin, M. Scarcioffolo, J. Schafer, T. Schanz, S. Schlenstedt, R. Schlickeiser, T. Schmidt, J. Schmoll, P. Schovanek, M. Schroedter, A. Schubert, C. Schultz, J. Schultze, A. Schulz, K. Schure, F. Schussler, T. Schwab, U. Schwanke, J. Schwarz, S. Schwarzburg, T. Schweizer, S. Schwemmer, U. Schwendicke, C. Schwerdt, A. Segreto, J. -H. Seiradakis, G. H. Sembroski, M. Servillat, K. Seweryn, M. Sharma, M. Shayduk, R. C. Shellard, J. Shi, T. Shibata, A. Shibuya, S. Shore, E. Shum, E. Sideras-Haddad, L. Sidoli, M. Sidz, J. Sieiro, M. Sikora, J. Silk, A. Sillanpää, B. B. Singh, G. Sironi, J. Sitarek, C. Skole, R. Smareglia, A. Smith, D. Smith, J. Smith, N. Smith, D. Sobczyńska, H. Sol, G. Sottile, M. Sowiński, F. Spanier, D. Spiga, S. Spyrou, V. Stamatescu, A. Stamerra, R. L. C. Starling, Ł. Stawarz, R. Steenkamp, C. Stegmann, S. Steiner, C. Stella, N. Stergioulas, R. Sternberger, M. Sterzel, F. Stinzing, M. Stodulski, Th. Stolarczyk, U. Straumann, E. Strazzeri, L. Stringhetti, A. Suarez, M. Suchenek, R. Sugawara, K. -H. Sulanke, S. Sun, A. D. Supanitsky, T. Suric, P. Sutcliffe, J. M. Sykes, M. Szanecki, T. Szepieniec, A. Szostek, G. Tagliaferri, H. Tajima, H. Takahashi, K. Takahashi, L. Takalo, H. Takami, G. Talbot, J. Tammi, M. Tanaka, S. Tanaka, J. Tasan, M. Tavani, J. -P. Tavernet, L. A. Tejedor, I. Telezhinsky, P. Temnikov, C. Tenzer, Y. Terada, R. Terrier, M. Teshima, V. Testa, D. Tezier, J. Thayer, D. Thuermann, L. Tibaldo, L. Tibaldo, O. Tibolla, A. Tiengo, M. C. Timpanaro, M. Tluczykont, C. J. Todero Peixoto, F. Tokanai, M. Tokarz, K. Toma, A. Tonachini, K. Torii, M. Tornikoski, D. F. Torres, M. Torres, S. Toscano, G. Toso, G. Tosti, T. Totani, F. Toussenel, G. Tovmassian, P. Travnicek, A. Treves, M. Trifoglio, I. Troyano, K. Tsinganos, H. Ueno, G. Umana, K. Umehara, S. S. Upadhya, T. Usher, M. Uslenghi, F. Vagnetti, J. F. Valdes-Galicia, P. Vallania, G. Vallejo, W. van Driel, C. van Eldik, J. Vandenbrouke, J. Vanderwalt, H. Vankov, G. Vasileiadis, V. Vassiliev, D. Veberic, I. Vegas, S. Vercellone, S. Vergani, V. Verzi, G. P. Vettolani, C. Veyssière, J. P. Vialle, A. Viana, M. Videla, C. Vigorito, P. Vincent, S. Vincent, J. Vink, N. Vlahakis, L. Vlahos, P. Vogler, V. Voisin, A. Vollhardt, H. -P. von Gunten, S. Vorobiov, C. Vuerli, V. Waegebaert, R. Wagner, R. G. Wagner, S. Wagner, S. P. Wakely, R. Walter, T. Walther, K. Warda, R. S. Warwick, P. Wawer, R. Wawrzaszek, N. Webb, P. Wegner, A. Weinstein, Q. Weitzel, R. Welsing, M. Werner, H. Wetteskind, R. J. White, A. Wierzcholska, S. Wiesand, A. Wilhelm, M. I. Wilkinson, D. A. Williams, R. Willingale, M. Winde, K. Winiarski, R. Wischnewski, Ł. Wiśniewski, P. Wojcik, M. Wood, A. Wörnlein, Q. Xiong, K. K. Yadav, H. Yamamoto, T. Yamamoto, R. Yamazaki, S. Yanagita, J. M. Yebras, D. Yelos, A. Yoshida, T. Yoshida, T. Yoshikoshi, P. Yu, V. Zabalza, M. Zacharias, A. Zajczyk, L. Zampieri, R. Zanin, A. Zdziarski, A. Zech, A. Zhao, X. Zhou, K. Zietara, J. Ziolkowski, P. Ziółkowski, V. Zitelli, C. Zurbach, P. Zychowski

Compilation of CTA contributions to the proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), which took place in 2-9 July, 2013, in Rio de Janeiro, Brazil Read More

2013Jun
Authors: F. Acero, M. Ackermann, M. Ajello, A. Allafort, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, R. D. Blandford, E. D. Bloom, E. Bonamente, E. Bottacini, T. J. Brandt, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, C. Cecchi, E. Charles, R. C. G. Chaves, A. Chekhtman, J. Chiang, G. Chiaro, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, S. Cutini, M. Dalton, F. D'Ammando, F. de Palma, C. D. Dermer, L. Di Venere, E. do Couto e Silva, P. S. Drell, A. Drlica-Wagner, L. Falletti, C. Favuzzi, S. J. Fegan, E. C. Ferrara, W. B. Focke, A. Franckowiak, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, D. Gasparrini, N. Giglietto, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, T. Grégoire, I. A. Grenier, M. -H. Grondin, J. E. Grove, S. Guiriec, D. Hadasch, Y. Hanabata, A. K. Harding, M. Hayashida, K. Hayashi, E. Hays, J. Hewitt, A. B. Hill, D. Horan, X. Hou, R. E. Hughes, Y. Inoue, M. S. Jackson, T. Jogler, G. Jóhannesson, A. S. Johnson, T. Kamae, T. Kawano, M. Kerr, J. Knödlseder, M. Kuss, J. Lande, S. Larsson, L. Latronico, M. Lemoine-Goumard, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, M. Marelli, F. Massaro, M. Mayer, M. N. Mazziotta, J. E. McEnery, J. Mehault, P. F. Michelson, W. Mitthumsiri, T. Mizuno, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, T. Nakamori, R. Nemmen, E. Nuss, T. Ohsugi, A. Okumura, M. Orienti, E. Orlando, J. F. Ormes, D. Paneque, J. H. Panetta, J. S. Perkins, M. Pesce-Rollins, F. Piron, G. Pivato, T. A. Porter, S. Rainò, R. Rando, M. Razzano, A. Reimer, O. Reimer, T. Reposeur, S. Ritz, M. Roth, R. Rousseau, P. M. Saz Parkinson, A. Schulz, C. Sgrò, E. J. Siskind, D. A. Smith, G. Spandre, P. Spinelli, D. J. Suson, H. Takahashi, Y. Takeuchi, J. G. Thayer, J. B. Thayer, D. J. Thompson, L. Tibaldo, O. Tibolla, M. Tinivella, D. F. Torres, G. Tosti, E. Troja, Y. Uchiyama, J. Vandenbroucke, V. Vasileiou, G. Vianello, V. Vitale, M. Werner, B. L. Winer, K. S. Wood, Z. Yang

Pulsar wind nebulae (PWNe) have been established as the most populous class of TeV gamma-ray emitters. Since launch, the Fermi Large Area Telescope (LAT)identified five high-energy (100MeV Read More

We present results from three nearly simultaneous NuSTAR and Chandra monitoring observations between 2012 Sep 2 and 2012 Nov 16 of local star-forming galaxy NGC 253. The 3-40 keV NuSTAR intensity of the inner 20 arcsec (~400 pc) nuclear region varied by a factor of ~2 across the three monitoring observations. The Chandra data reveal that the nuclear region contains three bright X-ray sources, including a luminous (L2-10 keV ~ few x 10^39 erg/s) point source ~1 arcsec from the dynamical center of the galaxy (within the 3sigma positional uncertainty of the dynamical center); this source drives the overall variability of the nuclear region at energies >3 keV. Read More

2013Feb
Authors: The Fermi-LAT collaboration, :, M. Ackermann, M. Ajello, A. Allafort, L. Baldini, J. Ballet, G. Barbiellini, M. G. Baring, D. Bastieri, K. Bechtol, R. Bellazzini, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, E. Bottacini, T. J. Brandt, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, G. Busetto, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, J. M. Casandjian, C. Cecchi, Ö. Çelik, E. Charles, S. Chaty, R. C. G. Chaves, A. Chekhtman, C. C. Cheung, J. Chiang, G. Chiaro, A. N. Cillis, S. Ciprini, R. Claus, J. Cohen-Tanugi, L. R. Cominsky, J. Conrad, S. Corbel, S. Cutini, F. D'Ammando, A. de Angelis, F. de Palma, C. D. Dermer, E. do Couto e Silva, P. S. Drell, A. Drlica-Wagner, L. Falletti, C. Favuzzi, E. C. Ferrara, A. Franckowiak, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, S. Germani, N. Giglietto, P. Giommi, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, I. A. Grenier, M. -H. Grondin, J. E. Grove, S. Guiriec, D. Hadasch, Y. Hanabata, A. K. Harding, M. Hayashida, K. Hayashi, E. Hays, J. Hewitt, A. B. Hill, R. E. Hughes, M. S. Jackson, T. Jogler, G. Jóhannesson, A. S. Johnson, T. Kamae, J. Kataoka, J. Katsuta, J. Knödlseder, M. Kuss, J. Lande, S. Larsson, L. Latronico, M. Lemoine-Goumard, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, G. M. Madejski, F. Massaro, M. Mayer, M. N. Mazziotta, J. E. McEnery, J. Mehault, P. F. Michelson, R. P. Mignani, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, T. Nakamori, R. Nemmen, E. Nuss, M. Ohno, T. Ohsugi, N. Omodei, M. Orienti, E. Orlando, J. F. Ormes, D. Paneque, J. S. Perkins, M. Pesce-Rollins, F. Piron, G. Pivato, S. Rainò, R. Rando, M. Razzano, S. Razzaque, A. Reimer, O. Reimer, S. Ritz, C. Romoli, M. Sánchez-Conde, A. Schulz, C. Sgrò, P. E. Simeon, E. J. Siskind, D. A. Smith, G. Spandre, P. Spinelli, F. W. Stecker, A. W. Strong, D. J. Suson, H. Tajima, H. Takahashi, T. Takahashi, T. Tanaka, J. G. Thayer, J. B. Thayer, D. J. Thompson, S. E. Thorsett, L. Tibaldo, O. Tibolla, M. Tinivella, E. Troja, Y. Uchiyama, T. L. Usher, J. Vandenbroucke, V. Vasileiou, G. Vianello, V. Vitale, A. P. Waite, M. Werner, B. L. Winer, K. S. Wood, M. Wood, R. Yamazaki, Z. Yang, S. Zimmer

Cosmic rays are particles (mostly protons) accelerated to relativistic speeds. Despite wide agreement that supernova remnants (SNRs) are the sources of galactic cosmic rays, unequivocal evidence for the acceleration of protons in these objects is still lacking. When accelerated protons encounter interstellar material, they produce neutral pions, which in turn decay into gamma rays. Read More

2012Nov
Authors: H. J. Pletsch, L. Guillemot, H. Fehrmann, B. Allen, M. Kramer, C. Aulbert, M. Ackermann, M. Ajello, A. de Angelis, W. B. Atwood, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, A. W. Borgland, E. Bottacini, T. J. Brandt, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, J. M. Casandjian, C. Cecchi, Ö. Celik, E. Charles, R. C. G. Chaves, C. C. Cheung, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, S. Cutini, F. D'Ammando, C. D. Dermer, S. W. Digel, P. S. Drell, A. Drlica-Wagner, R. Dubois, D. Dumora, C. Favuzzi, E. C. Ferrara, A. Franckowiak, Y. Fukazawa, P. Fusco, F. Gargano, N. Gehrels, S. Germani, N. Giglietto, F. Giordano, M. Giroletti, G. Godfrey, I. A. Grenier, M. -H. Grondin, J. E. Grove, S. Guiriec, D. Hadasch, Y. Hanabata, A. K. Harding, P. R. den Hartog, M. Hayashida, E. Hays, A. B. Hill, X. Hou, R. E. Hughes, G. Johannesson, M. S. Jackson, T. Jogler, A. S. Johnson, W. N. Johnson, J. Kataoka, M. Kerr, J. Knödlseder, M. Kuss, J. Lande, S. Larsson, L. Latronico, M. Lemoine-Goumard, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, F. Massaro, M. Mayer, M. N. Mazziotta, J. E. McEnery, J. Mehault, P. F. Michelson, W. Mitthumsiri, T. Mizuno, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, T. Nakamori, R. Nemmen, E. Nuss, M. Ohno, T. Ohsugi, N. Omodei, M. Orienti, E. Orlando, F. de Palma, D. Paneque, J. S. Perkins, F. Piron, G. Pivato, T. A. Porter, S. Raino, R. Rando, P. S. Ray, M. Razzano, A. Reimer, O. Reimer, T. Reposeur, S. Ritz, R. W. Romani, C. Romoli, D. A. Sanchez, P. M. Saz Parkinson, A. Schulz, C. Sgro, E. do Couto e Silva, E. J. Siskind, D. A. Smith, G. Spandre, P. Spinelli, D. J. Suson, H. Takahashi, T. Tanaka, J. B. Thayer, J. G. Thayer, D. J. Thompson, L. Tibaldo, M. Tinivella, E. Troja, T. L. Usher, J. Vandenbroucke, V. Vasileiou, G. Vianello, V. Vitale, A. P. Waite, B. L. Winer, K. S. Wood, M. Wood, Z. Yang, S. Zimmer

Millisecond pulsars, old neutron stars spun-up by accreting matter from a companion star, can reach high rotation rates of hundreds of revolutions per second. Until now, all such "recycled" rotation-powered pulsars have been detected by their spin-modulated radio emission. In a computing-intensive blind search of gamma-ray data from the Fermi Large Area Telescope (with partial constraints from optical data), we detected a 2. Read More

2012Jul
Authors: M. Ackermann, M. Ajello, A. Allafort, E. Antolini, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, B. Berenji, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, E. Bottacini, T. J. Brandt, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, C. Cecchi, A. Chekhtman, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, F. D'Ammando, A. de Angelis, F. de Palma, C. D. Dermer, E. do Couto e Silva, P. S. Drell, A. Drlica-Wagner, T. Enoto, L. Falletti, C. Favuzzi, S. J. Fegan, E. C. Ferrara, W. B. Focke, Y. Fukazawa, Y. Fukui, P. Fusco, F. Gargano, D. Gasparrini, S. Germani, N. Giglietto, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, S. Guiriec, D. Hadasch, Y. Hanabata, A. K. Harding, M. Hayashida, K. Hayashi, D. Horan, X. Hou, R. E. Hughes, M. S. Jackson, G. Jóhannesson, A. S. Johnson, T. Kamae, H. Katagiri, J. Kataoka, M. Kerr, J. Knödlseder, M. Kuss, J. Lande, S. Larsson, S. -H. Lee, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, K. Makishima, M. N. Mazziotta, J. Mehault, W. Mitthumsiri, A. A. Moiseev, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, T. Nakamori, M. Naumann-Godo, S. Nishino, J. P. Norris, E. Nuss, M. Ohno, T. Ohsugi, A. Okumura, M. Orienti, E. Orlando, J. F. Ormes, M. Ozaki, D. Paneque, J. H. Panetta, D. Parent, V. Pelassa, M. Pesce-Rollins, M. Pierbattista, F. Piron, G. Pivato, T. A. Porter, S. Rainò, M. Razzano, A. Reimer, O. Reimer, M. Roth, H. F. -W. Sadrozinski, C. Sgrò, E. J. Siskind, G. Spandre, P. Spinelli, A. W. Strong, H. Takahashi, T. Takahashi, T. Tanaka, J. G. Thayer, J. B. Thayer, O. Tibolla, M. Tinivella, D. F. Torres, A. Tramacere, E. Troja, Y. Uchiyama, T. L. Usher, J. Vandenbroucke, V. Vasileiou, G. Vianello, V. Vitale, A. P. Waite, P. Wang, B. L. Winer, K. S. Wood, Z. Yang, S. Zimmer

We report on the gamma-ray observations of giant molecular clouds Orion A and B with the Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope. The gamma-ray emission in the energy band between \sim100 MeV and \sim100 GeV is predicted to trace the gas mass distribution in the clouds through nuclear interactions between the Galactic cosmic rays (CRs) and interstellar gas. The gamma-ray production cross-section for the nuclear interaction is known to \sim10% precision which makes the LAT a powerful tool to measure the gas mass column density distribution of molecular clouds for a known CR intensity. Read More

Spatial extension is an important characteristic for correctly associating gamma-ray-emitting sources with their counterparts at other wavelengths and for obtaining an unbiased model of their spectra. We present a new method for quantifying the spatial extension of sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi). We perform a series of Monte Carlo simulations to validate this tool and calculate the LAT threshold for detecting the spatial extension of sources. Read More

2012Jun
Authors: Fermi LAT Collaboration, M. Ackermann, M. Ajello, A. Allafort, L. Baldini, J. Ballet, D. Bastieri, K. Bechtol, R. Bellazzini, B. Berenji, E. D. Bloom, E. Bonamente, A. W. Borgland, A. Bouvier, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, J. M. Casandjian, C. Cecchi, E. Charles, A. Chekhtman, C. C. Cheung, J. Chiang, A. N. Cillis, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, S. Cutini, F. De Palma, C. D. Dermer, S. W. Digel, E. Do Couto e Silva, P. S. Drell, A. Drlica-Wagner, C. Favuzzi, S. J. Fegan, P. Fortin, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, D. Gasparrini, S. Germani, N. Giglietto, F. Giordano, T. Glanzman, G. Godfrey, I. A. Grenier, S. Guiriec, M. Gustafsson, D. Hadasch, M. Hayashida, E. Hays, R. E. Hughes, G. Jóhannesson, A. S. Johnson, T. Kamae, H. Katagiri, J. Kataoka, J. Knödlseder, M. Kuss, J. Lande, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, G. M. Madejski, P. Martin, M. N. Mazziotta, J. E. McEnery, P. F. Michelson, T. Mizuno, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, S. Nishino, J. P. Norris, E. Nuss, M. Ohno, T. Ohsugi, A. Okumura, N. Omodei, E. Orlando, M. Ozaki, D. Parent, M. Persic, M. Pesce-Rollins, V. Petrosian, M. Pierbattista, F. Piron, G. Pivato, T. A. Porter, S. Rainò, R. Rando, M. Razzano, A. Reimer, O. Reimer, S. Ritz, M. Roth, C. Sbarra, C. Sgrò, E. J. Siskind, G. Spandre, P. Spinelli, \{L}ukasz Stawarz, A. W. Strong, H. Takahashi, T. Tanaka, J. B. Thayer, L. Tibaldo, M. Tinivella, D. F. Torres, G. Tosti, E. Troja, Y. Uchiyama, J. Vandenbroucke, G. Vianello, V. Vitale, A. P. Waite, M. Wood, Z. Yang

Recent detections of the starburst galaxies M82 and NGC 253 by gamma-ray telescopes suggest that galaxies rapidly forming massive stars are more luminous at gamma-ray energies compared to their quiescent relatives. Building upon those results, we examine a sample of 69 dwarf, spiral, and luminous and ultraluminous infrared galaxies at photon energies 0.1-100 GeV using 3 years of data collected by the Large Area Telescope (LAT) on the \textit{Fermi Gamma-ray Space Telescope} (\textit{Fermi}). Read More

2012May
Authors: The Fermi-LAT collaboration, :, M. Ackermann, M. Ajello, W. B. Atwood, L. Baldini, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, R. D. Blandford, E. D. Bloom, E. Bonamente, A. W. Borgland, E. Bottacini, T. J. Brandt, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, J. M. Casandjian, C. Cecchi, E. Charles, A. Chekhtman, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, A. Cuoco, S. Cutini, F. D'Ammando, A. de Angelis, F. de Palma, C. D. Dermer, E. do Couto e Silva, P. S. Drell, A. Drlica-Wagner, L. Falletti, C. Favuzzi, S. J. Fegan, W. B. Focke, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, D. Gasparrini, S. Germani, N. Giglietto, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, I. A. Grenier, S. Guiriec, M. Gustafsson, D. Hadasch, M. Hayashida, D. Horan, R. E. Hughes, M. S. Jackson, T. Jogler, G. Jóhannesson, A. S. Johnson, T. Kamae, J. Knödlseder, M. Kuss, J. Lande, L. Latronico, A. M. Lionetto, M. Llena Garde, F. Longo, F. Loparco, B. Lott, M. N. Lovellette, P. Lubrano, M. N. Mazziotta, J. E. McEnery, J. Mehault, P. F. Michelson, W. Mitthumsiri, T. Mizuno, A. A. Moiseev, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, M. Naumann-Godo, J. P. Norris, E. Nuss, T. Ohsugi, M. Orienti, E. Orlando, J. F. Ormes, D. Paneque, J. H. Panetta, M. Pesce-Rollins, M. Pierbattista, F. Piron, G. Pivato, H. Poon, S. Rainò, R. Rando, M. Razzano, S. Razzaque, A. Reimer, O. Reimer, C. Romoli, C. Sbarra, J. D. Scargle, C. Sgrò, E. J. Siskind, G. Spandre, P. Spinelli, Łukasz Stawarz, A. W. Strong, D. J. Suson, H. Tajima, H. Takahashi, T. Tanaka, J. G. Thayer, J. B. Thayer, L. Tibaldo, M. Tinivella, G. Tosti, E. Troja, T. L. Usher, J. Vandenbroucke, V. Vasileiou, G. Vianello, V. Vitale, A. P. Waite, E. Wallace, K. S. Wood, M. Wood, Z. Yang, G. Zaharijas, S. Zimmer

We have performed an analysis of the diffuse gamma-ray emission with the Fermi Large Area Telescope in the Milky Way Halo region searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal, constraints are presented. We consider both gamma rays produced directly in the dark matter annihilation/decay and produced by inverse Compton scattering of the e+e- produced in the annihilation/decay. Read More