Search Publications
Disappearance of the Progenitor of Supernova iPTF13bvn
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Foley, Ryan J. +13 more
Supernova (SN) iPTF13bvn in NGC 5806 was the first Type Ib SN to have been tentatively associated with a progenitor in pre-explosion images. We performed deep ultraviolet (UV) and optical Hubble Space Telescope observations of the SN site ∼740 days after explosion. We detect an object in the optical bands that is fainter than the pre-explosion obj…
An Enhanced Rate of Tidal Disruptions in the Centrally Overdense E+A Galaxy NGC 3156
Stone, Nicholas C.; van Velzen, Sjoert
Time domain optical surveys have discovered roughly a dozen candidate stellar tidal disruption flares in the last five years, and future surveys like the Large Synoptic Survey Telescope will likely find hundreds to thousands more. These tidal disruption events (TDEs) present an interesting puzzle: a majority of the current TDE sample is hosted by …
The Relation between Solar Eruption Topologies and Observed Flare Features. II. Dynamical Evolution
Pariat, E.; DeLuca, E. E.; McKillop, S. +4 more
A long-established goal of solar physics is to build understanding of solar eruptions and develop flare and coronal mass ejection (CME) forecasting models. In this paper, we continue our investigation of nonlinear forces free field (NLFFF) models by comparing topological properties of the solutions to the evolution of the flare ribbons. In particu…
The Very Massive Star Content of the Nuclear Star Clusters in NGC 5253
Crowther, P. A.; Calzetti, D.; Smith, L. J. +1 more
The blue compact dwarf galaxy NGC 5253 hosts a very young starburst containing twin nuclear star clusters, separated by a projected distance of 5 pc. One cluster (#5) coincides with the peak of the Hα emission and the other (#11) with a massive ultracompact H II region. A recent analysis of these clusters shows that they have a photometric age of …
Discovery of a Substellar Companion to the Nearby Debris Disk Host HR 2562
Matthews, Brenda C.; Duchêne, Gaspard; Esposito, Thomas M. +54 more
We present the discovery of a brown dwarf companion to the debris disk host star HR 2562. This object, discovered with the Gemini Planet Imager (GPI), has a projected separation of 20.3 ± 0.3 au (0\buildrel{\prime\prime}\over{.} 618+/- 0\buildrel{\prime\prime}\over{.} 004) from the star. With the high astrometric precision afforded by GPI, we have…
Measurements of Water Surface Snow Lines in Classical Protoplanetary Disks
Zhang, Ke; Banzatti, Andrea; Najita, Joan R. +5 more
We present deep Herschel-PACS spectroscopy of far-infrared water lines from a sample of four protoplanetary disks around solar-mass stars, selected to have strong water emission at mid-infrared wavelengths. By combining the new Herschel spectra with archival Spitzer-IRS spectroscopy, we retrieve a parameterized radial surface water vapor distribut…
The MOSDEF Survey: Detection of [O III]λ4363 and the Direct-method Oxygen Abundance of a Star-forming Galaxy at z = 3.08
Siana, Brian; Shapley, Alice E.; Reddy, Naveen A. +8 more
We present measurements of the electron-temperature-based oxygen abundance for a highly star-forming galaxy at z = 3.08, COSMOS-1908. This is the highest redshift at which [O III]λ4363 has been detected and the first time that this line has been measured at z\gt 2. We estimate an oxygen abundance of 12+{log}({{O}}/{{H}})={8.00}-0.14
Bright Galaxies at Hubble’s Redshift Detection Frontier: Preliminary Results and Design from the Redshift z ~ 9-10 BoRG Pure-Parallel HST Survey
Shull, J. M.; Brammer, G.; Treu, T. +14 more
We present the first results and design from the redshift z ∼ 9-10 Brightest of the Reionizing Galaxies Hubble Space Telescope survey BoRG[z9-10], aimed at searching for intrinsically luminous unlensed galaxies during the first 700 Myr after the Big Bang. BoRG[z9-10] is the continuation of a multi-year pure-parallel near-IR and optical imaging cam…
Measurements of Non-thermal Line Widths in Solar Active Regions
Warren, Harry P.; Brooks, David H.
Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal heating. Here we present a survey of non-thermal velocities measured in the high temperature loops (1-4 MK) o…
Late-time Photometry of Type Ia Supernova SN 2012cg Reveals the Radioactive Decay of 57 Co
Rest, Armin; Riess, Adam G.; Graur, Or +3 more
Seitenzahl et al. have predicted that roughly three years after its explosion, the light we receive from a Type Ia supernova (SN Ia) will come mostly from reprocessing of electrons and X-rays emitted by the radioactive decay chain 57Co → 57Fe, instead of positrons from the decay chain 56Co → 56Fe that do…