M. Sullivan - School of Physics and Astronomy, University of Southampton

M. Sullivan
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M. Sullivan
School of Physics and Astronomy, University of Southampton
United Kingdom

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High Energy Astrophysical Phenomena (29)
Solar and Stellar Astrophysics (20)
Cosmology and Nongalactic Astrophysics (19)
Astrophysics of Galaxies (6)
Instrumentation and Methods for Astrophysics (4)
Mathematics - Symplectic Geometry (4)
High Energy Physics - Phenomenology (3)
High Energy Physics - Experiment (3)
Mathematical Physics (1)
Mathematics - Mathematical Physics (1)
Mathematics - Quantum Algebra (1)
Mathematics - Geometric Topology (1)
Mathematics - Representation Theory (1)
Nuclear Experiment (1)
Physics - Accelerator Physics (1)

Publications Authored By M. Sullivan

The requirements-driven OSIRIS-REx Camera Suite (OCAMS) acquires images essential to collecting a sample from the surface of Bennu. During proximity operations, these images document the presence of satellites and plumes, record spin state, enable an accurate digital terrain model of the shape of the asteroid and identify any surface hazards. They confirm the presence of sampleable regolith on the surface, observe the sampling event itself, and image the sample head in order to verify its readiness to be stowed. Read More

We present the transient source detection efficiencies of the Palomar Transient Factory (PTF), parameterizing the number of transients that PTF found, versus the number of similar transients that occurred over the same period in the survey search area but that were missed. PTF was an optical sky survey carried out with the Palomar 48-inch telescope over 2009-2012, observing more than 8000 square degrees of sky with cadences of between 1 and 5 days, locating around 50,000 non-moving transient sources, and spectroscopically confirming around 1900 supernovae. We assess the effectiveness with which PTF detected transient sources, by inserting ~7 million artificial point sources into real PTF data. Read More

Type Ibn supernovae (SNe Ibn) are thought to be the core-collapse explosions of massive stars whose ejecta interact with He-rich circumstellar material (CSM). We report the discovery of a SN Ibn, with the longest rise-time ever observed, OGLE-2014-SN-131. We discuss the potential powering mechanisms and the progenitor nature of this peculiar stripped-envelope (SE), circumstellar-interacting SN. Read More

We study augmentations of a Legendrian surface $L$ in the $1$-jet space, $J^1M$, of a surface $M$. We introduce two types of algebraic/combinatorial structures related to the front projection of $L$ that we call chain homotopy diagrams (CHDs) and Morse complex $2$-families (MC2Fs), and show that the existence of either a $\rho$-graded CHD or MC2F is equivalent to the existence of a $\rho$-graded augmentation of the Legendrian contact homology DGA to $\mathbb{Z}/2$. A CHD is an assignment of chain complexes, chain maps, and homotopy operators to the $0$-, $1$-, and $2$-cells of a compatible polygonal decomposition of the base projection of $L$ with restrictions arising from the front projection of $L$. Read More

The simplest extension of the Standard Model is to add a gauge singlet scalar, $S$: the singlet extended Standard Model. In the absence of a $Z_2$ symmetry $S\rightarrow -S$ and if the new scalar is sufficiently heavy, this model can lead to resonant double Higgs production, significantly increasing the production rate over the Standard Model prediction. While searches for this signal are being performed, it is important to have benchmark points and models with which to compare the experimental results. Read More

We present late-time optical $R$-band imaging data from the Palomar Transient Factory (PTF) for the nearby type Ia supernova SN 2011fe. The stacked PTF light curve provides densely sampled coverage down to $R\simeq22$ mag over 200 to 620 days past explosion. Combining with literature data, we estimate the pseudo-bolometric light curve for this event from 200 to 1600 days after explosion, and constrain the likely near-infrared contribution. Read More

With the advent of new wide-field, high-cadence optical transient surveys, our understanding of the diversity of core-collapse supernovae has grown tremendously in the last decade. However, the pre-supernova evolution of massive stars, that sets the physical backdrop to these violent events, is theoretically not well understood and difficult to probe observationally. Here we report the discovery of the supernova iPTF13dqy = SN 2013fs, a mere ~3 hr after explosion. Read More

We consider inhomogeneous supersymmetric bilinear forms, i.e., forms that are neither even nor odd. Read More

The coming era of large photometric wide-field surveys will increase the detection rate of supernovae by orders of magnitude. Such numbers will restrict spectroscopic follow-up in the vast majority of cases, and hence new methods based solely on photometric data must be developed. Here, we construct a complete Hubble diagram of Type II supernovae combining data from three different samples: the Carnegie Supernova Project-I, the Sloan Digital Sky Survey-II SN, and the Supernova Legacy Survey. Read More

We present and analyse an extensive dataset of the superluminous supernova (SLSN) LSQ14mo (z = 0.256), consisting of a multi-colour lightcurve from -30 d to +70 d in the rest-frame and a series of 6 spectra from PESSTO covering -7 d to +50 d. This is among the densest spectroscopic coverage, and best-constrained rising lightcurve, for a fast-declining hydrogen-poor SLSN. Read More

We report initial observations and analysis on the Type IIb SN~2016gkg in the nearby galaxy NGC~613. SN~2016gkg exhibited a clear double-peaked light curve during its early evolution, as evidenced by our intensive photometric follow-up campaign. SN~2016gkg shows strong similarities with other Type IIb SNe, in particular with respect to the \he~emission features observed in both the optical and near infrared. Read More

We report the discovery of a multiply-imaged gravitationally lensed Type Ia supernova, iPTF16geu (SN 2016geu), at redshift $z=0.409$. This phenomenon could be identified because the light from the stellar explosion was magnified more than fifty times by the curvature of space around matter in an intervening galaxy. Read More

A beam optics scheme has been designed for the Future Circular Collider-e+e- (FCC-ee). The main characteristics of the design are: beam energy 45 to 175 GeV, 100 km circumference with two interaction points (IPs) per ring, horizontal crossing angle of 30 mrad at the IP and the crab-waist scheme [1] with local chromaticity correction. The crab-waist scheme is implemented within the local chromaticity correction system without additional sextupoles, by reducing the strength of one of the two sextupoles for vertical chromatic correction at each side of the IP. Read More

Affiliations: 1University of Southampton, 2Dark Cosmology Centre, 3Kyoto Sangyo University, 4University of Southampton, 5University of Leicester, 6SUPA University of St Andrews, 7University of Cambridge, 8Kavli Institute for Cosmology, 9University of Southampton, 10University of Oxford, 11University of Southampton, 12University of Southampton

The time lag between optical and near-infrared continuum emission in active galactic nuclei (AGN) shows a tight correlation with luminosity and has been proposed as a standardisable candle for cosmology. In this paper, we explore the use of these AGN hot-dust time lags for cosmological model fitting under the constraints of the new VISTA Extragalactic Infrared Legacy Survey VEILS. This new survey will target a 9 deg^2 field observed in J- and Ks-band with a 14-day cadence and will run for three years. Read More

We present the light curves of the hydrogen-poor superluminous supernovae (SLSNe-I) PTF12dam and iPTF13dcc, discovered by the (intermediate) Palomar Transient Factory. Both show excess emission at early times and a slowly declining light curve at late times. The early bump in PTF12dam is very similar in duration (~10 days) and brightness relative to the main peak (2-3 mag fainter) compared to those observed in other SLSNe-I. Read More

We present photometry and time-series spectroscopy of the nearby type Ia supernova (SN Ia) SN 2015F over $-16$ days to $+80$ days relative to maximum light, obtained as part of the Public ESO Spectroscopic Survey of Transient Objects (PESSTO). SN 2015F is a slightly sub-luminous SN Ia with a decline rate of $\Delta m15(B)=1.35 \pm 0. Read More

When a star passes within the tidal radius of a supermassive black hole, it will be torn apart. For a star with the mass of the Sun ($M_\odot$) and a non-spinning black hole with a mass $<10^8 M_\odot$, the tidal radius lies outside the black hole event horizon and the disruption results in a luminous flare. Here we report observations over a period of 10 months of a transient, hitherto interpreted as a superluminous supernova. Read More

Authors: Jim Alexander, Marco Battaglieri, Bertrand Echenard, Rouven Essig, Matthew Graham, Eder Izaguirre, John Jaros, Gordan Krnjaic, Jeremy Mardon, David Morrissey, Tim Nelson, Maxim Perelstein, Matt Pyle, Adam Ritz, Philip Schuster, Brian Shuve, Natalia Toro, Richard G Van De Water, Daniel Akerib, Haipeng An, Konrad Aniol, Isaac J. Arnquist, David M. Asner, Henning O. Back, Keith Baker, Nathan Baltzell, Dipanwita Banerjee, Brian Batell, Daniel Bauer, James Beacham, Jay Benesch, James Bjorken, Nikita Blinov, Celine Boehm, Mariangela Bondí, Walter Bonivento, Fabio Bossi, Stanley J. Brodsky, Ran Budnik, Stephen Bueltmann, Masroor H. Bukhari, Raymond Bunker, Massimo Carpinelli, Concetta Cartaro, David Cassel, Gianluca Cavoto, Andrea Celentano, Animesh Chaterjee, Saptarshi Chaudhuri, Gabriele Chiodini, Hsiao-Mei Sherry Cho, Eric D. Church, D. A. Cooke, Jodi Cooley, Robert Cooper, Ross Corliss, Paolo Crivelli, Francesca Curciarello, Annalisa D'Angelo, Hooman Davoudiasl, Marzio De Napoli, Raffaella De Vita, Achim Denig, Patrick deNiverville, Abhay Deshpande, Ranjan Dharmapalan, Bogdan Dobrescu, Sergey Donskov, Raphael Dupre, Juan Estrada, Stuart Fegan, Torben Ferber, Clive Field, Enectali Figueroa-Feliciano, Alessandra Filippi, Bartosz Fornal, Arne Freyberger, Alexander Friedland, Iftach Galon, Susan Gardner, Francois-Xavier Girod, Sergei Gninenko, Andrey Golutvin, Stefania Gori, Christoph Grab, Enrico Graziani, Keith Griffioen, Andrew Haas, Keisuke Harigaya, Christopher Hearty, Scott Hertel, JoAnne Hewett, Andrew Hime, David Hitlin, Yonit Hochberg, Roy J. Holt, Maurik Holtrop, Eric W. Hoppe, Todd W. Hossbach, Lauren Hsu, Phil Ilten, Joe Incandela, Gianluca Inguglia, Kent Irwin, Igal Jaegle, Robert P. Johnson, Yonatan Kahn, Grzegorz Kalicy, Zhong-Bo Kang, Vardan Khachatryan, Venelin Kozhuharov, N. V. Krasnikov, Valery Kubarovsky, Eric Kuflik, Noah Kurinsky, Ranjan Laha, Gaia Lanfranchi, Dale Li, Tongyan Lin, Mariangela Lisanti, Kun Liu, Ming Liu, Ben Loer, Dinesh Loomba, Valery E. Lyubovitskij, Aaron Manalaysay, Giuseppe Mandaglio, Jeremiah Mans, W. J. Marciano, Thomas Markiewicz, Luca Marsicano, Takashi Maruyama, Victor A. Matveev, David McKeen, Bryan McKinnon, Dan McKinsey, Harald Merkel, Jeremy Mock, Maria Elena Monzani, Omar Moreno, Corina Nantais, Sebouh Paul, Michael Peskin, Vladimir Poliakov, Antonio D Polosa, Maxim Pospelov, Igor Rachek, Balint Radics, Mauro Raggi, Nunzio Randazzo, Blair Ratcliff, Alessandro Rizzo, Thomas Rizzo, Alan Robinson, Andre Rubbia, David Rubin, Dylan Rueter, Tarek Saab, Elena Santopinto, Richard Schnee, Jessie Shelton, Gabriele Simi, Ani Simonyan, Valeria Sipala, Oren Slone, Elton Smith, Daniel Snowden-Ifft, Matthew Solt, Peter Sorensen, Yotam Soreq, Stefania Spagnolo, James Spencer, Stepan Stepanyan, Jan Strube, Michael Sullivan, Arun S. Tadepalli, Tim Tait, Mauro Taiuti, Philip Tanedo, Rex Tayloe, Jesse Thaler, Nhan V. Tran, Sean Tulin, Christopher G. Tully, Sho Uemura, Maurizio Ungaro, Paolo Valente, Holly Vance, Jerry Vavra, Tomer Volansky, Belina von Krosigk, Andrew Whitbeck, Mike Williams, Peter Wittich, Bogdan Wojtsekhowski, Wei Xue, Jong Min Yoon, Hai-Bo Yu, Jaehoon Yu, Tien-Tien Yu, Yue Zhang, Yue Zhao, Yiming Zhong, Kathryn Zurek

This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years. Read More

We prove that the number of Reeb chords between a Legendrian submanifold and its contact Hamiltonian push-off is at least the sum of the $\mathbb{Z}_2$-Betti numbers of the submanifold, provided that the contact isotopy is sufficiently small when compared to the smallest Reeb chord on the Legendrian. Moreover, the established invariance enables us to use two different contact forms: one for the count of Reeb chords and another for the measure of the smallest length, under the assumption that there is a suitable symplectic cobordism from the latter to the former. The size of the contact isotopy is measured in terms of the oscillation of the contact Hamiltonian, together with the maximal factor by which the contact form is shrunk during the isotopy. Read More

We give a computation of the Legendrian contact homology (LCH) DGA for an arbitrary generic Legendrian surface $L$ in the $1$-jet space of a surface. As input we require a suitable cellular decomposition of the base projection of $L$. A collection of generators is associated to each cell, and the differential is given by explicit matrix formulas. Read More

Nebular-phase observations and spectral models of Type Ic superluminous supernovae are presented. LSQ14an and SN 2015bn both display late-time spectra similar to galaxy-subtracted spectra of SN 2007bi, and the class shows strong similarity with broad-lined Type Ic SNe such as SN 1998bw. Near-infrared observations of SN 2015bn show a strong Ca II triplet, O I 9263, O I 1. Read More

This article is a continuation of [15]. For Legendrian surfaces in $1$-jet spaces, we prove that the Cellular DGA defined in [15] is stable tame isomorphic to the Legendrian contact homology DGA. Read More

Type Ibn supernovae (SNe) are a small yet intriguing class of explosions whose spectra are characterized by low-velocity helium emission lines with little to no evidence for hydrogen. The prevailing theory has been that these are the core-collapse explosions of very massive stars embedded in helium-rich circumstellar material (CSM). We report optical observations of six new SNe Ibn: PTF11rfh, PTF12ldy, iPTF14aki, iPTF15ul, SN 2015G, and iPTF15akq. Read More

We present optical and near-infrared photometric and spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 days after the explosion. SN 2013ej is a hydrogen-rich supernova, classified as a Type IIL due to its relatively fast decline following the initial peak. It has a relatively high peak luminosity (absolute magnitude M$_\rm{V}$ = -17. Read More

We present a measurement of the volumetric rate of superluminous supernovae (SLSNe) at z~1, measured using archival data from the first four years of the Canada-France-Hawaii Telescope Supernova Legacy Survey (SNLS). We develop a method for the photometric classification of SLSNe to construct our sample. Our sample includes two previously spectroscopically-identified objects, and a further new candidate selected using our classification technique. Read More

The progenitors of some supernovae (SNe) exhibit outbursts with super-Eddington luminosities prior to their final explosions. This behavior is common among Type IIn SNe, but the driving mechanisms of these precursors are not yet well understood. SNHunt 275 was announced as a possible new SN during May 2015. Read More

Host galaxy identification is a crucial step for modern supernova (SN) surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST), which will discover SNe by the thousands. Spectroscopic resources are limited, so in the absence of real-time SN spectra these surveys must rely on host galaxy spectra to obtain accurate redshifts for the Hubble diagram and to improve photometric classification of SNe. In addition, SN luminosities are known to correlate with host-galaxy properties. Read More

Given a non-semisimple automorphism $\varphi$ of a vertex algebra $V$, the fields in a $\varphi$-twisted $V$-module involve the logarithm of the formal variable, and the action of the Virasoro operator $L_0$ on such module is not semisimple. We construct examples of such modules and realize them explicitly as Fock spaces when $V$ is generated by free fields. Specifically, we consider the cases of symplectic fermions (odd superbosons), free fermions, and $\beta\gamma$-system (even superfermions). Read More

We report photometric and spectroscopic observations of the optical transient LSQ13zm. Historical data reveal the presence of an eruptive episode (that we label as `2013a') followed by a much brighter outburst (`2013b') three weeks later, that we argue to be the genuine supernova explosion. This sequence of events closely resemble those observed for SN2010mc and (in 2012) SN2009ip. Read More

High-quality collections of Type II supernova (SN) light curves are scarce because they evolve for hundreds of days, making follow-up observations time consuming and often extending over multiple observing seasons. In light of these difficulties, the diversity of SNe II is not fully understood. Here we present ultraviolet and optical photometry of 12 SNe II monitored by the Las Cumbres Observatory Global Telescope Network (LCOGT) during 2013-2014, and compare them with previously studied SNe having well-sampled light curves. Read More

The LaSilla/QUEST Variability Survey (LSQ) and the Carnegie Supernova Project (CSP II) are collaborating to discover and obtain photometric light curves for a large sample of low redshift (z < 0.1) Type Ia supernovae. The supernovae are discovered in the LSQ survey using the 1 m ESO Schmidt telescope at the La Silla Observatory with the 10 square degree QUEST camera. Read More

Affiliations: 1Queen's University Belfast, 2Queen's University Belfast, 3Queen's University Belfast, 4Stockholm University, 5Yale University, 6Queen's University Belfast, 7Yale University, 8University of Cambridge, 9MPE Garching, 10Universität Würzburg, 11Weizmann Institute of Science, 12Millennium Institute, Santiago, 13MPA Garching, 14Queen's University Belfast, 15Queen's University Belfast, 16UPMC Paris, 17University of Warwick, 18Queen's University Belfast, 19Heidelberger Institut for Theoretische Studien, 20Heidelberger Institut for Theoretische Studien, 21Australian National University, 22Australian National University, 23University of Southampton, 24University of California, 25Queen's University Belfast

We present results based on observations of SN 2015H which belongs to the small group of objects similar to SN 2002cx, otherwise known as type Iax supernovae. The availability of deep pre-explosion imaging allowed us to place tight constraints on the explosion epoch. Our observational campaign began approximately one day post-explosion, and extended over a period of about 150 days post maximum light, making it one of the best observed objects of this class to date. Read More

The near-maximum spectra of most superluminous supernovae that are not dominated by interaction with a H-rich CSM (SLSN-I) are characterised by a blue spectral peak and a series of absorption lines which have been identified as OII. SN2011kl, associated with the ultra-long gamma-ray burst GRB111209A, also had a blue peak but a featureless optical/UV spectrum. Radiation transport methods are used to show that the spectra (not including SN2007bi, which has a redder spectrum at peak, like ordinary SNe Ic) can be explained by a rather steep density distribution of the ejecta, whose composition appears to be typical of carbon-oxygen cores of massive stars which can have low metal content. Read More

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 direct detection of a stellar system that explodes as a Type Ia supernova (SN Ia) has not yet been successful. Various indirect methods have been used to investigate SN Ia progenitor systems but none have produced conclusive results. A prediction of single-degenerate models is that H- (or He-) rich material from the envelope of the companion star should be swept up by the SN ejecta in the explosion. Read More

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, 73the DES Collaboration, 74the DES Collaboration, 75the DES Collaboration, 76the DES Collaboration, 77the DES Collaboration, 78the DES Collaboration, 79the DES Collaboration, 80the DES Collaboration, 81the DES Collaboration, 82the DES Collaboration, 83the DES Collaboration, 84the DES Collaboration

We present DES14X3taz, a new hydrogen-poor super luminous supernova (SLSN-I) discovered by the Dark Energy Survey (DES) supernova program, with additional photometric data provided by the Survey Using DECam for Superluminous Supernovae (SUDSS). Spectra obtained using OSIRIS on the Gran Telescopio CANARIAS (GTC) show DES14X3taz is a SLSN-I at z=0.608. Read More

Long duration gamma-ray bursts are a rare subclass of stripped-envelope core-collapse supernovae that launch collimated relativistic outflows (jets). All gamma-ray-burst-associated supernovae are spectroscopically of Type Ic with broad lines, but the fraction of broad-lined Type Ic supernovae harboring low-luminosity gamma-ray-burst remains largely unconstrained. Some supernovae should be accompanied by off-axis $\gamma$-ray burst jets that remain invisible initially, but then emerge as strong radio sources (as the jets decelerate). Read More

Supernovae (SNe) embedded in dense circumstellar material (CSM) may show prominent emission lines in their early-time spectra ($\leq 10$ days after the explosion), owing to recombination of the CSM ionized by the shock-breakout flash. From such spectra ("flash spectroscopy"), we can measure various physical properties of the CSM, as well as the mass-loss rate of the progenitor during the year prior to its explosion. Searching through the Palomar Transient Factory (PTF and iPTF) SN spectroscopy databases from 2009 through 2014, we found 12 Type II SNe showing flash-ionized (FI) signatures in their first spectra. Read More

During the first few days after explosion, Type II supernovae (SNe) are dominated by relatively simple physics. Theoretical predictions regarding early-time SN light curves in the ultraviolet (UV) and optical bands are thus quite robust. We present, for the first time, a sample of $57$ $R$-band Type II SN light curves that are well monitored during their rise, having $>5$ detections during the first 10 days after discovery, and a well-constrained time of explosion to within $1-3$ days. Read More

Affiliations: 1ICG Portsmouth, 2ICG Portsmouth, 3ICG Portsmouth, 4University of Southampton, 5University of Southampton

We predict cosmological constraints for forthcoming surveys using Superluminous Supernovae (SLSNe) as standardisable candles. Due to their high peak luminosity, these events can be observed to high redshift (z~3), opening up new possibilities to probe the Universe in the deceleration epoch. We describe our methodology for creating mock Hubble diagrams for the Dark Energy Survey (DES), the "Search Using DECam for Superluminous Supernovae" (SUDSS) and a sample of SLSNe possible from the Large Synoptic Survey Telescope (LSST), exploring a range of standardisation values for SLSNe. Read More

A model for composite elementary Standard Model (SM) particles based upon magnetically bound vorton pairs, briefly introduced here, predicts the existence of a complete family of magnetically charged particles, as well as their neutral isotopic partners (all counterparts to the SM elementary particles), in which the lowest mass (charged) particle would be an electrically neutral stable lepton, but which carries a magnetic charge equivalent to 1e. This new particle, which we call a magneticon (a counterpart to the electron) would be pair produced at all e+e- colliders at an Ecm above twice its mass. In addition, PP and PPbar colliders should also be able to produce these new particles through the Drell-Yan process. Read More

Affiliations: 1Queen's University Belfast, 2Queen's University Belfast, 3Universite Cote d'Azur, 4University of Cambridge, 5Weizmann Institute of Science, 6Queen's University Belfast, 7Queen's University Belfast, 8Queen's University Belfast, 9Stockholm University, 10Yale University, 11Yale University, 12INAF-Padova, 13INAF-Napoli, 14University of Cambridge, 15MPE Garching, 16Millennium Institute, Santiago, 17Yale University, 18Queen's University Belfast, 19Queen's University Belfast, 20University of Southampton, 21Millennium Institute, Santiago, 22University of California Davis, 23Queen's University Belfast

We present optical imaging and spectroscopy of supernova (SN) LSQ13fn, a type II supernova with several hitherto-unseen properties. Although it initially showed strong symmetric spectral emission features attributable to \ion{He}{ii}, \ion{N}{iii}, and \ion{C}{iii}, reminiscent of some interacting SNe, it transitioned into an object that would fall more naturally under a type II-Plateau (IIP) classification. However, its spectral evolution revealed several unusual properties: metal lines appeared later than expected, were weak, and some species were conspicuous by their absence. Read More

We present observations of four rapidly rising (t_{rise}~10d) transients with peak luminosities between those of supernovae (SNe) and superluminous SNe (M_{peak}~-20) - one discovered and followed by the Palomar Transient Factory (PTF) and three by the Supernova Legacy Survey (SNLS). The light curves resemble those of SN 2011kl, recently shown to be associated with an ultra-long-duration gamma ray burst (GRB), though no GRB was seen to accompany our SNe. The rapid rise to a luminous peak places these events in a unique part of SN phase space, challenging standard SN emission mechanisms. Read More

We present the complete set of ultra-violet, optical and near-infrared photometry and spectroscopy for SN 2012ca, covering the period from 6~days prior to maximum light, until 531 days after maximum. The spectroscopic time series for SN 2012ca is essentially unchanged over 1.5 years, and appear to be dominated at all epochs by signatures of interaction with a dense circumstellar medium rather than the underlying supernova (SN). Read More

We present photometric and spectroscopic observations of SN 2013fc, a bright type II supernova (SN) in a circumnuclear star-forming ring in the luminous infrared galaxy ESO 154-G010, observed as part of the Public ESO Spectroscopic Survey of Transient Objects (PESSTO). SN 2013fc is both photometrically and spectroscopically similar to the well-studied type IIn SN 1998S and to the bright type II-L SN 1979C. It exhibits an initial linear decline, followed by a short plateau phase and a tail phase with a decline too fast for $^{56}$Co decay with full gamma-ray trapping. Read More

We use observed UV through near IR spectra to examine whether SN 2011fe can be understood in the framework of Branch-normal SNe Ia and to examine its individual peculiarities. As a benchmark, we use a delayed-detonation model with a progenitor metallicity of Z_solar/20. We study the sensitivity of features to variations in progenitor metallicity, the outer density profile, and the distribution of radioactive nickel. Read More

The progenitor stars of several Type IIb supernovae (SNe) show indications for extended hydrogen envelopes. These envelopes might be the outcome of luminous energetic pre-explosion events, so-called precursor eruptions. We use the Palomar Transient Factory (PTF) pre-explosion observations of a sample of 27 nearby Type IIb SNe to look for such precursors during the final years prior to the SN explosion. Read More

We describe the difference imaging pipeline (DiffImg) used to detect transients in deep images from the Dark Energy Survey Supernova program (DES-SN) in its first observing season from Aug 2013 through Feb 2014. DES-SN is a search for transients in which ten 3-deg^2 fields are repeatedly observed in the g,r,i,z passbands with a cadence of about 1 week. The observing strategy has been optimized to measure high-quality light curves and redshifts for thousands of Type Ia supernova (SN Ia) with the goal of measuring dark energy parameters. Read More

The light curves of Type Ia supernovae (SNe Ia) are powered by the radioactive decay of $^{56}$Ni to $^{56}$Co at early times, and the decay of $^{56}$Co to $^{56}$Fe from ~60 days after explosion. We examine the evolution of the [Co III] 5892 A emission complex during the nebular phase for SNe Ia with multiple nebular spectra and show that the line flux follows the square of the mass of $^{56}$Co as a function of time. This result indicates both efficient local energy deposition from positrons produced in $^{56}$Co decay, and long-term stability of the ionization state of the nebula. Read More