Astrophysics of Galaxies Publications (50)

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Astrophysics of Galaxies Publications

To shed light on the time evolution of local star formation episodes in M33, we study the association between 566 Giant Molecular Clouds (GMCs), identified through the CO (J=2-1) IRAM-all-disk survey, and 630 Young Stellar Cluster Candidates (YSCCs), selected via Spitzer-24~$\mu$m emission. The spatial correlation between YSCCs and GMCs is extremely strong, with a typical separation of 17~pc, less than half the CO(2--1) beamsize, illustrating the remarkable physical link between the two populations. GMCs and YSCCs follow the HI filaments, except in the outermost regions where the survey finds fewer GMCs than YSCCs, likely due to undetected, low CO-luminosity clouds. Read More


We introduce and present results from the COCOA (Cluster simulatiOn Comparison with ObservAtions) code that has been developed to create idealized mock photometric observations using results from numerical simulations of star cluster evolution. COCOA is able to present the output of realistic numerical simulations of star clusters carried out using Monte Carlo or N-body codes in a way that is useful for direct comparison with photometric observations. In this paper, we describe the COCOA code and demonstrate its different applications by utilizing globular cluster (GC) models simulated with the MOCCA code. Read More


We use the Sloan Digital Sky Survey Data Release 12, which is the largest available white dwarf catalog to date, to study the evolution of the kinematical properties of the population of white dwarfs in the Galactic disc. We derive masses, ages, photometric distances and radial velocities for all white dwarfs with hydrogen-rich atmospheres. For those stars for which proper motions from the USNO-B1 catalog are available the true three-dimensional components of the stellar space velocity are obtained. Read More


We investigate the formation of circumstellar disks and outflows subsequent to the collapse of molecular cloud cores with the magnetic field and turbulence. Numerical simulations are performed by using an adaptive mesh refinement to follow the evolution up to $\sim 1000$~yr after the formation of a protostar. In the simulations, circumstellar disks are formed around the protostars; those in magnetized models are considerably smaller than those in nonmagnetized models, but their size increases with time. Read More


We analyze theoretically the Schrodinger-Poisson equation in two transverse dimensions in the presence of a Kerr term. The model describes the nonlinear propagation of optical beams in thermooptical media and can be regarded as an analogue system for a self-gravitating self-interacting wave. We compute numerically the family of radially symmetric ground state bright stationary solutions for focusing and defocusing local nonlinearity, keeping in both cases a focusing nonlocal nonlinearity. Read More


The Mid-Infrared Instrument (MIRI) for the {\em James Webb Space Telescope} (JWST) will revolutionize our understanding of infrared stellar populations in the Local Volume. Using the rich {\em Spitzer}-IRS spectroscopic data-set and spectral classifications from the Surveying the Agents of Galaxy Evolution (SAGE)-Spectroscopic survey of over a thousand objects in the Magellanic Clouds, the Grid of Red supergiant and Asymptotic giant branch star ModelS ({\sc grams}), and the grid of YSO models by Robitaille et al. (2006), we calculate the expected flux-densities and colors in the MIRI broadband filters for prominent infrared stellar populations. Read More


We analyze a sample of $z$-dropout galaxies in the CANDELS GOODS South and UDS fields that have been targeted by a dedicated spectroscopic campaign aimed at detecting their Ly$\alpha$ line. Deep IRAC observations at 3.6 and 4. Read More


We aim at characterizing the large-scale distribution of H2O in G327.3-0.6, a massive star-forming region made of individual objects in different evolutionary phases. Read More


We search type 1 AGNs among emission-line galaxies, that are typically classified as type 2 AGNs based on emission line flux ratios if a broad component in the H$\alpha$ line profile is not properly investigated. Using ~24,000 type 2 AGNs at z $<$0.1 initially selected from Sloan Digital Sky Survey Data Release 7 by Bae, et al. Read More


Follow-up observations at high-angular resolution of submillimeter galaxies showed that the single-dish sources are comprised of a blend of several galaxies. Consequently, number counts derived from low and high angular resolution observations are in disagreement. This demonstrates the importance of resolution effects and the need to have realistic simulations to explore them. Read More


Turbulence models attempt to account for unresolved dynamics and diffusion in hydrodynamical simulations. We develop a common framework for two-equation Reynolds-Averaged Navier-Stokes (RANS) turbulence models, and we implement six models in the Athena code. We verify each implementation with the standard subsonic mixing layer, although the level of agreement depends on the definition of the mixing layer width. Read More


We study the intra-cluster magnetic field in the poor galaxy cluster Abell 194 by complementing radio data, at different frequencies, with data in the optical and X-ray bands. We analyze new total intensity and polarization observations of Abell 194 obtained with the Sardinia Radio Telescope (SRT). We use the SRT data in combination with archival Very Large Array observations to derive both the spectral aging and Rotation Measure (RM) images of the radio galaxies 3C40A and 3C40B embedded in Abell 194. Read More


The latest measurements of CMB electron scattering optical depth reported by Planck significantly reduces the allowed space of HI reionization models, pointing towards a later ending and/or less extended phase transition than previously believed. Reionization impulsively heats the intergalactic medium (IGM) to $\sim10^4$ K, and owing to long cooling and dynamical times in the diffuse gas, comparable to the Hubble time, memory of reionization heating is retained. Therefore, a late ending reionization has significant implications for the structure of the $z\sim5-6$ Lyman-$\alpha$ (ly$\alpha$) forest. Read More


HOCO$^+$ is a polar molecule that represents a useful proxy for its parent molecule CO$_2$, which is not directly observable in the cold interstellar medium. This cation has been detected towards several lines of sight, including massive star forming regions, protostars, and cold cores. Despite the obvious astrochemical relevance, protonated CO$_2$ and its deuterated variant, DOCO$^+$, still lack an accurate spectroscopic characterisation. Read More


We explore the effects of the expected higher cosmic ray (CR) ionization rates $\zeta_{\rm CR}$ on the abundances of carbon monoxide (CO), atomic carbon (C), and ionized carbon (C$^+$) in the H$_2$ clouds of star-forming galaxies. The study of Bisbas et al. (2015) is expanded by: a) using realistic inhomogeneous Giant Molecular Cloud (GMC) structures, b) a detailed chemical analysis behind the CR-induced destruction of CO, and c) exploring the thermal state of CR-irradiated molecular gas. Read More


Recent observations have revealed massive galactic molecular outflows that may have physical conditions (high gas densities) required to form stars. Indeed, several recent models predict that such massive galactic outflows may ignite star formation within the outflow itself. This star-formation mode, in which stars form with high radial velocities, could contribute to the morphological evolution of galaxies, to the evolution in size and velocity dispersion of the spheroidal component of galaxies, and would contribute to the population of high-velocity stars, which could even escape the galaxy. Read More


We analyze the environmental properties of 370 present-day early-type galaxies in the MASSIVE and ATLAS3D surveys, two complementary volume-limited integral-field spectroscopic (IFS) galaxy surveys spanning absolute $K$-band magnitude $-21.5 > M_K > -26.6$, or stellar mass $6\ times 10^{9} < M_* < 2 \times 10^{12} M_\odot$. Read More


Could there be intermediate mass black holes in essentially all old dwarf galaxies? I argue that current observations of Active Galactic Nuclei in dwarfs allow such a radical hypothesis which provides early feedback and potentially provides a unifying explanation for many if not all of the apparent dwarf galaxy anomalies, such as the abundance, core-cusp, "too big to fail", ultra-faint and baryon-fraction issues. I describe the supporting arguments, which are largely circumstantial in nature, and discuss a number of tests. There is no strong motivation for modifying the nature of cold dark matter in order to explain any of the dwarf galaxy "problems". Read More


We study the formation of runaway stars due to binary-binary (2+2) interactions in young star-forming clusters and/or associations. This is done using a combination of analytic methods and numerical simulations of 2+2 scattering interactions, both in isolation and in a homogeneous background potential. We focus on interactions that produce two single stars and a binary, and study the outcomes as a function of the depth of the background potential, within a range typical of cluster cores. Read More


Galaxy clusters are known to induce gas loss in infalling galaxies due to the ram pressure exerted by the intracluster medium over their gas content. In this paper, we investigate this process through a set of simulations of Milky Way like galaxies falling inside idealised clusters of 10$^{14}$ M$_\odot$ and 10$^{15}$ M$_\odot$, containing a cool-core or not, using the adaptive mesh refinement code RAMSES. We use these simulations to constrain how much of the initial mass contained in the gaseous disk of the galaxy will be converted into stars and how much of it will be lost, after a single crossing of the entire cluster. Read More


We study the effect of density fluctuations induced by turbulence on the HI/H$_2$ structure in photodissociation regions (PDRs) both analytically and numerically. We perform magnetohydrodynamic numerical simulations for both subsonic and supersonic turbulent gas and chemical HI/H$_2$ balance calculations. We derive atomic-to-molecular density profiles and the HI column density probability density function (PDF). Read More


We present analyses of the spatial distributions of stars in the young (1 - 3 Myr) star-forming regions IC348 and NGC1333 in the Perseus Giant Molecular Cloud. We quantify the spatial structure using the $\mathcal{Q}$-parameter and find that both IC348 and NGC1333 are smooth and centrally concentrated with $\mathcal{Q}$-parameters of 0.98 and 0. Read More


The $\sigma$ Orionis cluster is important for studying protoplanetary disk evolution, as its intermediate age ($\sim$3-5 Myr) is comparable to the median disk lifetime. We use ALMA to conduct a high-sensitivity survey of dust and gas in 92 protoplanetary disks around $\sigma$ Orionis members with $M_{\ast}\gtrsim0.1 M_{\odot}$. Read More


In this paper, we study the 3-body products (two single stars and a binary) of binary-binary (2+2) scattering interactions. This is done using a combination of analytic methods and numerical simulations of 2+2 scattering interactions, both in isolation and in a homogeneous background potential. We derive analytically a simple formula relating the angle between the velocity vectors of the two ejected single stars and the orbital separation of the remaining binary. Read More


2017Mar
Affiliations: 1Max-Planck-Institut für Radioastronomie, 2Max-Planck-Institut für Radioastronomie, 3Max-Planck-Institut für Radioastronomie, 4School of Physical Sciences, University of Kent, 5Max-Planck-Institut für Radioastronomie, 6Max-Planck-Institut für Radioastronomie, 7Max-Planck-Institut für Radioastronomie, 8Max-Planck-Institut für Radioastronomie

(Abridged) Aims: We aim to use the progressive heating of the gas caused by the feedback of high-mass young stellar objects (YSOs) to prove the statistical validity of the most common schemes used to define an evolutionary sequence for high-mass clumps, and characterise the sensitivity of different tracers to this process. Methods: From the spectroscopic follow-ups of the ATLASGAL TOP100 sample, we selected several multiplets of CH3CN, CH3CCH, and CH3OH emission lines to derive and compare the physical properties of the gas in the clumps along the evolutionary sequence. Our findings are compared with results obtained from CO isotopologues, dust, and NH3 from previous studies on the same sample. Read More


The archival data of 3C 345, a type 1 quasar at $z = 0.5928$, obtained with Suzaku and Swift/BAT are analysed. Though previous studies of this source applied only a simple broken power law model, a heavily obscuring material is found to be required by considering Akaike information criteria. Read More


A conclusive model for the formation of dwarf spheroidal (dSph) galaxies still remains elusive. Owing to their proximity to the massive spirals Milky Way (MW) and M31, various environmental processes have been invoked to explain their origin. In this context, the tidal stirring model postulates that interactions with MW-sized hosts can transform rotationally supported dwarfs, resembling present-day dwarf irregular (dIrr) galaxies, into systems with the kinematic and structural properties of dSphs. Read More


We calculated the polarization degree of hydrogen Balmer broad emission lines from a number of active galactic nuclei (AGNs) with determined virial factors. The objects were selected from the sample presented by Decarli et al.(2008). Read More


We propose an innovative method for measuring the neutral hydrogen (HI) content of an optically-selected spectroscopic sample of galaxies through cross-correlation with HI intensity mapping measurements. We show that the HI-galaxy cross-power spectrum contains an additive shot noise term which scales with the average HI brightness temperature of the optically-selected galaxies, allowing constraints to be placed on the average HI mass per galaxy. This approach can estimate the HI content of populations too faint to directly observe through their 21cm emission over a wide range of redshifts. Read More


2017Mar
Affiliations: 1Heidelberg University, 2Dublin City University, 3Heidelberg University, 4Dublin City University, 5Uppsala University

A near pristine atomic cooling halo close to a star forming galaxy offers a natural pathway for forming massive direct collapse black hole (DCBH) seeds which could be the progenitors of the $z>6$ redshift quasars. The close proximity of the haloes enables a sufficient Lyman-Werner flux to effectively dissociate H$_2$ in the core of the atomic cooling halo. A mild background may also be required to delay star formation in the atomic cooling halo, often attributed to distant background galaxies. Read More


We present a hierarchical probabilistic model for improving geometric stellar distance estimates using color--magnitude information. This is achieved with a data driven model of the color--magnitude diagram, not relying on stellar models but instead on the relative abundances of stars in color--magnitude cells, which are inferred from very noisy magnitudes and parallaxes. While the resulting noise-deconvolved color--magnitude diagram can be useful for a range of applications, we focus on deriving improved stellar distance estimates relying on both parallax and photometric information. Read More


In this work we study the mass distribution of two irregular galaxies, UGC 6446 and UGC 7524, by means of HI rotation curves derived from high resolution HI velocity fields obtained through the Westerbork Synthesis Radio Telescope data archive. We constrain the stellar and gas content of both galaxies with stellar population synthesis models and by deriving the HI+He+metals rotation curves from the total HI surface density maps, respectively. The discrepancy between the circular velocity maxima of the stellar plus the HI+He+metals rotation curves and the observed HI rotation curves of both galaxies requires the inclusion of a substantial amount of dark matter. Read More


As part of the Fornax Deep Survey with the ESO VLT Survey Telescope, we present new $g$ and $r$ bands mosaics of the SW group of the Fornax cluster. It covers an area of $3 \times 2$ square degrees around the central galaxy NGC1316. The deep photometry, the high spatial resolution of OmegaCam and the large covered area allow us to study the galaxy structure, to trace stellar halo formation and look at the galaxy environment. Read More


2017Mar
Affiliations: 1Astro Space Center of Lebedev Physical Institute, Moscow, Russia, 2Astro Space Center of Lebedev Physical Institute, Moscow, Russia, 3Max-Planck-Institut für Radioastronomie, Bonn, Germany, 4Aalto University Metsähovi Radio Observatory, Kylmälä, Finland, 5Astro Space Center of Lebedev Physical Institute, Moscow, Russia

We present a comprehensive 5-43 GHz VLBA study of the blazar 3C 273 initiated after an onset of a strong $\gamma$-ray flare in this source. We have analyzed the kinematics of new-born components, light curves, and position of the apparent core to pinpoint the location of the $\gamma$-ray emission. Estimated location of the $\gamma$-ray emission zone is close to the jet apex, 2 pc to 7 pc upstream from the observed 7 mm core. Read More


We have resolved for the first time the radial and vertical structure of the almost edge-on envelope/disk system of the low-mass Class 0 protostar L1527. For that, we have used ALMA observations with a spatial resolution of 0.25$^{\prime\prime}$$\times$0. Read More


Spin patterns of spiral galaxies can be broadly separated into galaxies with clockwise patterns and galaxies with counterclockwise spin patterns. While the differences between these patterns are visually noticeable, they are a matter of the perspective of the observer, and therefore in a sufficiently large universe no other differences are expected between galaxies with clockwise and counterclockwise spin patterns. Here large datasets of spiral galaxies separated by their spin patterns are used to show that spiral galaxies with clockwise spin patterns are photometrically different from spiral galaxies with counterclockwise patterns. Read More


We carried out multiwavelength (0.7-5 cm), multiepoch (1994-2015) Very Large Array (VLA) observations toward the region enclosing the bright far-IR sources FIR 3 (HOPS 370) and FIR 4 (HOPS 108) in OMC-2. We report the detection of 10 radio sources, seven of them identified as young stellar objects. Read More


We propose a new method for generating equilibrium models of spherical systems of collisionless particles that are finite in extent, but whose central regions resemble dark matter halos from cosmological simulations. This method involves iteratively removing unbound particles from a Navarro-Frenk-White profile truncated sharply at some radius. The resulting models are extremely stable, and thus provide a good starting point for N-body simulations of isolated halos. Read More


We address the physical nature of subdwarf A-type (sdA) stars and their possible link to extremely low mass (ELM) white dwarfs (WDs). The two classes of objects are confused in low-resolution spectroscopy. However, colors and proper motions indicate that sdA stars are cooler and more luminous, and thus larger in radius, than published ELM WDs. Read More


Gas surrounding high redshift galaxies has been studied through observations of absorption line systems toward background quasars for decades. However, it has proven difficult to identify and characterize the galaxies associated with these absorbers due to the intrinsic faintness of the galaxies compared to the quasars at optical wavelengths. Utilizing the Atacama Large Millimeter/Submillimeter Array, we report on detections of [CII] 158 micron line and dust continuum emission from two galaxies associated with two such absorbers at a redshift of z~4. Read More


2017Mar
Affiliations: 1University of Southampton, 2Kyoto Sangyo University

This letter presents a revised radiative transfer model for the infrared (IR) emission of active galactic nuclei (AGN). While current models assume that the IR is emitted from a dusty torus in the equatorial plane of the AGN, spatially resolved observations indicate that the majority of the IR emission from 100 pc in many AGN originates from the polar region, contradicting classical torus models. The new model CAT3D-WIND builds upon the suggestion that the dusty gas around the AGN consists of an inflowing disk and an outflowing wind. Read More


2017Mar
Authors: M. L. Ahnen1, S. Ansoldi2, L. A. Antonelli3, C. Arcaro4, A. Babić5, B. Banerjee6, P. Bangale7, U. Barres de Almeida8, J. A. Barrio9, J. Becerra González10, W. Bednarek11, E. Bernardini12, A. Berti13, B. Biasuzzi14, A. Biland15, O. Blanch16, S. Bonnefoy17, G. Bonnoli18, F. Borracci19, T. Bretz20, R. Carosi21, A. Carosi22, A. Chatterjee23, P. Colin24, E. Colombo25, J. L. Contreras26, J. Cortina27, S. Covino28, P. Cumani29, P. Da Vela30, F. Dazzi31, A. De Angelis32, B. De Lotto33, E. de Oña Wilhelmi34, F. Di Pierro35, M. Doert36, A. Domínguez37, D. Dominis Prester38, D. Dorner39, M. Doro40, S. Einecke41, D. Eisenacher Glawion42, D. Elsaesser43, M. Engelkemeier44, V. Fallah Ramazani45, A. Fernández-Barral46, D. Fidalgo47, M. V. Fonseca48, L. Font49, C. Fruck50, D. Galindo51, R. J. García López52, M. Garczarczyk53, M. Gaug54, P. Giammaria55, N. Godinović56, D. Gora57, D. Guberman58, D. Hadasch59, A. Hahn60, T. Hassan61, M. Hayashida62, J. Herrera63, J. Hose64, D. Hrupec65, G. Hughes66, W. Idec67, K. Ishio68, K. Kodani69, Y. Konno70, H. Kubo71, J. Kushida72, D. Lelas73, E. Lindfors74, S. Lombardi75, F. Longo76, M. López77, P. Majumdar78, M. Makariev79, K. Mallot80, G. Maneva81, M. Manganaro82, K. Mannheim83, L. Maraschi84, M. Mariotti85, M. Martínez86, D. Mazin87, U. Menzel88, R. Mirzoyan89, A. Moralejo90, E. Moretti91, D. Nakajima92, V. Neustroev93, A. Niedzwiecki94, M. Nievas Rosillo95, K. Nilsson96, K. Nishijima97, K. Noda98, L. Nogués99, M. Nöthe100, S. Paiano101, J. Palacio102, D. Paneque103, R. Paoletti104, J. M. Paredes105, X. Paredes-Fortuny106, G. Pedaletti107, M. Peresano108, L. Perri109, M. Persic110, J. Poutanen111, P. G. Prada Moroni112, E. Prandini113, I. Puljak114, J. R. Garcia115, I. Reichardt116, W. Rhode117, M. Ribó118, J. Rico119, T. Saito120, K. Satalecka121, S. Schroeder122, T. Schweizer123, S. N. Shore124, A. Sillanpää125, J. Sitarek126, I. Šnidarić127, D. Sobczynska128, A. Stamerra129, M. Strzys130, T. Surić131, L. Takalo132, F. Tavecchio133, P. Temnikov134, T. Terzić135, D. Tescaro136, M. Teshima137, D. F. Torres138, N. Torres-Albà139, T. Toyama140, A. Treves141, G. Vanzo142, M. Vazquez Acosta143, I. Vovk144, J. E. Ward145, M. Will146, M. H. Wu147, F. Krauß148, R. Schulz149, M. Kadler150, J. Wilms151, E. Ros152, U. Bach153, T. Beuchert154, M. Langejahn155, C. Wendel156, N. Gehrels157, W. H. Baumgartner158, C. B. Markwardt159, C. Müller160, V. Grinberg161, T. Hovatta162, J. Magill163
Affiliations: 1ETH Zurich, Institute for Particle Physics, Zurich, Switzerland, 2Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 3INAF - National Institute for Astrophysics, Roma, Italy, 4Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 5Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 6Saha Institute of Nuclear Physics, HBNI, Kolkata, India, 7Max-Planck-Institut für Physik, München, Germany, 8Max-Planck-Institut für Physik, München, Germany, 9Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 10Instituto de Astrofisica de Canarias, La Laguna, 11Division of Astrophysics, University of Lodz, Lodz, Poland, 12Deutsches Elektronen-Synchrotron, 13Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 14Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 15ETH Zurich, Institute for Particle Physics, Zurich, Switzerland, 16Institut de Fisica d'Altes Energies, 17Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 18Dipartimento di Fisica, Università di Siena and INFN sez. di Pisa, Siena, Italy, 19Max-Planck-Institut für Physik, München, Germany, 20Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 21Dipartimento di Fisica, Università di Siena and INFN sez. di Pisa, Siena, Italy, 22INAF - National Institute for Astrophysics, Roma, Italy, 23Saha Institute of Nuclear Physics, HBNI, Kolkata, India, 24Max-Planck-Institut für Physik, München, Germany, 25Instituto de Astrofisica de Canarias, La Laguna, 26Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 27Institut de Fisica d'Altes Energies, 28INAF - National Institute for Astrophysics, Roma, Italy, 29Institut de Fisica d'Altes Energies, 30Dipartimento di Fisica, Università di Siena and INFN sez. di Pisa, Siena, Italy, 31Max-Planck-Institut für Physik, München, Germany, 32Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 33Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 34Institut de Ciencies de l'Espai, 35INAF - National Institute for Astrophysics, Roma, Italy, 36Technische Universität Dortmund, Dortmund, Germany, 37Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 38Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 39Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 40Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 41Technische Universität Dortmund, Dortmund, Germany, 42Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 43Technische Universität Dortmund, Dortmund, Germany, 44Technische Universität Dortmund, Dortmund, Germany, 45Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 46Institut de Fisica d'Altes Energies, 47Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 48Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 49Universitat Autònoma de Barcelona, Barcelona, Spain, 50Max-Planck-Institut für Physik, München, Germany, 51Universitat de Barcelona, Barcelona, Spain, 52Instituto de Astrofisica de Canarias, La Laguna, 53Deutsches Elektronen-Synchrotron, 54Universitat Autònoma de Barcelona, Barcelona, Spain, 55INAF - National Institute for Astrophysics, Roma, Italy, 56Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 57Deutsches Elektronen-Synchrotron, 58Institut de Fisica d'Altes Energies, 59Japanese MAGIC Consortium, Kyoto, Japan, 60Max-Planck-Institut für Physik, München, Germany, 61Institut de Fisica d'Altes Energies, 62Japanese MAGIC Consortium, Kyoto, Japan, 63Instituto de Astrofisica de Canarias, La Laguna, 64Max-Planck-Institut für Physik, München, Germany, 65Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 66ETH Zurich, Institute for Particle Physics, Zurich, Switzerland, 67Division of Astrophysics, University of Lodz, Lodz, Poland, 68Max-Planck-Institut für Physik, München, Germany, 69Japanese MAGIC Consortium, Kyoto, Japan, 70Japanese MAGIC Consortium, Kyoto, Japan, 71Japanese MAGIC Consortium, Kyoto, Japan, 72Japanese MAGIC Consortium, Kyoto, Japan, 73Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 74Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 75INAF - National Institute for Astrophysics, Roma, Italy, 76Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 77Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 78Saha Institute of Nuclear Physics, HBNI, Kolkata, India, 79Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria, 80Deutsches Elektronen-Synchrotron, 81Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria, 82Instituto de Astrofisica de Canarias, La Laguna, 83Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 84INAF - National Institute for Astrophysics, Roma, Italy, 85Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 86Institut de Fisica d'Altes Energies, 87Max-Planck-Institut für Physik, München, Germany, 88Max-Planck-Institut für Physik, München, Germany, 89Max-Planck-Institut für Physik, München, Germany, 90Institut de Fisica d'Altes Energies, 91Max-Planck-Institut für Physik, München, Germany, 92Japanese MAGIC Consortium, Kyoto, Japan, 93Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 94Division of Astrophysics, University of Lodz, Lodz, Poland, 95Grupo de Altas Energias, Universidad Complutense, Madrid, Madrid, Spain, 96Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 97Japanese MAGIC Consortium, Kyoto, Japan, 98Max-Planck-Institut für Physik, München, Germany, 99Institut de Fisica d'Altes Energies, 100Technische Universität Dortmund, Dortmund, Germany, 101Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 102Institut de Fisica d'Altes Energies, 103Max-Planck-Institut für Physik, München, Germany, 104Dipartimento di Fisica, Università di Siena and INFN sez. di Pisa, Siena, Italy, 105Universitat de Barcelona, Barcelona, Spain, 106Universitat de Barcelona, Barcelona, Spain, 107Deutsches Elektronen-Synchrotron, 108Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 109INAF - National Institute for Astrophysics, Roma, Italy, 110Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 111Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 112Universita di Pisa, and INFN Pisa, Pisa, Italy, 113Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 114Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 115Max-Planck-Institut für Physik, München, Germany, 116Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 117Technische Universität Dortmund, Dortmund, Germany, 118Universitat de Barcelona, Barcelona, Spain, 119Institut de Fisica d'Altes Energies, 120Japanese MAGIC Consortium, Kyoto, Japan, 121Deutsches Elektronen-Synchrotron, 122Technische Universität Dortmund, Dortmund, Germany, 123Max-Planck-Institut für Physik, München, Germany, 124Universita di Pisa, and INFN Pisa, Pisa, Italy, 125Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 126Division of Astrophysics, University of Lodz, Lodz, Poland, 127Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 128Division of Astrophysics, University of Lodz, Lodz, Poland, 129INAF - National Institute for Astrophysics, Roma, Italy, 130Max-Planck-Institut für Physik, München, Germany, 131Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 132Finnish MAGIC Consortium, Tuorla Observatory, University of Turku and Astronomy Division, University of Oulu, Finland, Piikkiö, Finland, 133INAF - National Institute for Astrophysics, Roma, Italy, 134Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria, 135Croatian MAGIC Consortium: Rudjer Boskovic Institute, University of Rijeka, University of Split - FESB, University of Zagreb-FER, University of Osijek, Split, Croatia, 136Dipartimento di Fisica ed Astronomia, Università di Padova and INFN sez. di Padova, Padova, Italy, 137Max-Planck-Institut für Physik, München, Germany, 138ICREA and Institut de Ciencies de l'Espai, 139Universitat de Barcelona, Barcelona, Spain, 140Max-Planck-Institut für Physik, München, Germany, 141Università di Udine and INFN, sezione di Trieste, Italy, Udine, Italy, 142Instituto de Astrofisica de Canarias, La Laguna, 143Instituto de Astrofisica de Canarias, La Laguna, 144Max-Planck-Institut für Physik, München, Germany, 145Institut de Fisica d'Altes Energies, 146Instituto de Astrofisica de Canarias, La Laguna, 147Institut de Ciencies de l'Espai, 148GRAPPA and Anton Pannekoek Institute for Astronomy, University of Amsterdam, The Netherlands, 149ASTRON, the Netherlands Institute for Radio Astronomy, Dwingeloo, Netherlands, 150Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 151Dr. Remeis Sternwarte and ECAP, Universität Erlangen-Nürnberg, Bamberg, Germany, 152Max-Planck-Institut für Radioastronomie, Bonn, Germany, 153Max-Planck-Institut für Radioastronomie, Bonn, Germany, 154Dr. Remeis Sternwarte and ECAP, Universität Erlangen-Nürnberg, Bamberg, Germany, 155Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 156Institut für Theoretische Physik und Astrophysik - Fakultät für Physik und Astronomie - Universität Würzburg, Würzburg, Germany, 157NASA, Goddard Space Flight Center, Greenbelt, USA, 158NASA, Goddard Space Flight Center, Greenbelt, USA, 159NASA, Goddard Space Flight Center, Greenbelt, USA, 160Department of Astrophysics/IMAPP, Radboud University Nijmegen, Nijmegen, the Netherlands, 161Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, Cambridge, USA, 162Aalto University Metsähovi Radio Observatory, Kylmälä, Finland, 163Department of Physics and Department of Astronomy, University of Maryland, College Park, USA)

The extragalactic VHE gamma-ray sky is rich in blazars. These are jetted active galactic nuclei viewed at a small angle to the line-of-sight. Only a handful of objects viewed at a larger angle are known so far to emit above 100 GeV. Read More


This work employs a Gaussian mixture model (GMM) to jointly analyse two traditional emission-line classification schemes of galaxy ionization sources: the Baldwin-Phillips-Terlevich (BPT) and W$_{H\alpha}$ vs. [NII]/H$\alpha$ (WHAN) diagrams, using spectroscopic data from the Sloan Digital Sky Survey Data Release 7 and SEAGal/STARLIGHT datasets. We apply a GMM to empirically define classes of galaxies in a three-dimensional space spanned by the log [OIII]/H\beta, log [NII]/H\alpha, and log EW(H{\alpha}) optical parameters. Read More


We present MUSE observations of galaxy NGC 7469 from its Science Verification to show how powerful is the combination of high-resolution wide-field integral field spectroscopy with both photometric and spectroscopic observations of supernova (SN) explosions. Using STARLIGHT and HIIexplorer, we selected all Hii regions of the galaxy and produced 2- dimensional maps of the H{\alpha} equivalent width, average luminosity-weighted stellar age, and oxygen abundance. We measured deprojected galactocentric distances for all Hii regions, and radial gradients for all above-mentioned parameters. Read More


We present Canada-France-Hawaii Telescope (CFHT) MegaCam observations of a galaxy-quasar strong gravitational lens system, SDSS J1640+1932. This system, located at z=0.195 (foreground elliptical galaxy) and z=0. Read More