377 citations · 1.7k across the 20 of their papers we have counts for
20 papers
PSF Estimation in Crowded Astronomical Imagery as a Convolutional Dictionary Learning Problem
Brendt Wohlberg, Przemek Wozniak
We present a new algorithm for estimating the Point Spread Function (PSF) in wide-field astronomical images with extreme source crowding. Robust and accurate PSF estimation in crow…
A UV Resonance Line Echo from a Shell Around a Hydrogen-Poor Superluminous Supernova
R. Lunnan, C. Fransson, P. M. Vreeswijk +21
Hydrogen-poor superluminous supernovae (SLSN-I) are a class of rare and energetic explosions discovered in untargeted transient surveys in the past decade. The progenitor stars and…
Energetic eruptions leading to a peculiar hydrogen-rich explosion of a massive star
Iair Arcavi, D. Andrew Howell, Daniel Kasen +50
Every supernova hitherto observed has been considered to be the terminal explosion of a star. Moreover, all supernovae with absorption lines in their spectra show those lines decre…
iPTF16asu: A Luminous, Rapidly-Evolving, and High-Velocity Supernova
L. Whitesides, R. Lunnan, M. M. Kasliwal +23
Wide-field surveys are discovering a growing number of rare transients whose physical origin is not yet well understood. Here, we present optical and UV data and analysis of iPTF16…
Hydrogen-poor Superluminous Supernovae With Late-time H-alpha Emission: Three Events From the Intermediate Palomar Transient Factory
Lin Yan, R. Lunnan, D. Perley +20
We present observations of two new hydrogen-poor superluminous supernovae (SLSN-I), iPTF15esb and iPTF16bad, showing late-time H-alpha emission with line luminosities of (1-3)e+41…
Revisiting optical tidal disruption events with iPTF16axa
T. Hung, S. Gezari, N. Blagorodnova +12
We report the discovery by the intermediate Palomar Transient Factory (iPTF) of a candidate tidal disruption event (TDE) iPTF16axa at , and present its broadband photometr…
Confined Dense Circumstellar Material Surrounding a Regular Type II Supernova: The Unique Flash-Spectroscopy Event of SN 2013fs
O. Yaron, D. A. Perley, A. Gal-Yam +30
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.…
iPTF Discovery of the Rapid "Turn On" of a Luminous Quasar
S. Gezari, T. Hung, S. B. Cenko +13
We present a radio-quiet quasar at z=0.237 discovered "turning on" by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected by iPTF in the nucl…
Common Envelope ejection for a Luminous Red Nova in M101
N. Blagorodnova, R. Kotak, J. Polshaw +30
We present the results of optical, near-infrared, and mid-infrared observations of M101 OT2015-1 (PSN J14021678+5426205), a luminous red transient in the Pinwheel galaxy (M101), sp…
iPTF15dtg: a double-peaked Type Ic Supernova from a massive progenitor
F. Taddia, C. Fremling, J. Sollerman +9
Type Ic supernovae (SNe Ic) arise from the core-collapse of H (and He) poor stars, which could be either single WR stars or lower-mass stars stripped of their envelope by a compani…
Time-Varying Sodium Absorption in the Type Ia Supernova 2013gh
R. Ferretti, R. Amanullah, A. Goobar +18
Temporal variability of narrow absorption lines in high-resolution spectra of Type Ia supernovae (SNe Ia) is studied to search for circumstellar matter. Time series which resolve t…
Long-rising Type II supernovae from PTF and CCCP
F. Taddia, J. Sollerman, C. Fremling +17
Supernova (SN) 1987A was a peculiar H-rich event with a long-rising (LR) light curve (LC), stemming from a compact blue supergiant star (BSG). Only a few similar events have been p…
Integrating Temporal and Spectral Features of Astronomical Data Using Wavelet Analysis for Source Classification
T. N. Ukwatta, P. R. Wozniak
Temporal and spectral information extracted from a stream of photons received from astronomical sources is the foundation on which we build understanding of various objects and pro…
Flash Spectroscopy: Emission Lines from the Ionized Circumstellar Material around -Day-Old Type II Supernovae
D. Khazov, O. Yaron, A. Gal-Yam +24
Supernovae (SNe) embedded in dense circumstellar material (CSM) may show prominent emission lines in their early-time spectra ( days after the explosion), owing to recombi…
iPTF14yb: The First Discovery of a GRB Afterglow Independent of a High-Energy Trigger
S. Bradley Cenko, Alex L. Urban, Daniel A. Perley +34
We report here the discovery by the Intermediate Palomar Transient Factory (iPTF) of iPTF14yb, a luminous ( mag), cosmological (redshift 1.9733), rapidly fading…
GRB 081007 and GRB 090424: the surrounding medium, outflows and supernovae
Zhi-Ping Jin, Stefano Covino, Massimo Della Valle +34
We discuss the results of the analysis of multi-wavelength data for the afterglows of GRB 081007 and GRB 090424, two bursts detected by Swift. One of them, GRB 081007, also shows a…
On Estimating Non-uniform Density Distributions using N Nearest Neighbors
Przemek Wozniak, Andrzej Kruszewski
We consider density estimators based on the nearest neighbors method applied to discrete point distibutions in spaces of arbitrary dimensionality. If the density is constant, the v…
SkyDOT (Sky Database for Objects in the Time Domain): A Virtual Observatory for Variability Studies at LANL
P. Wozniak, K. Borozdin, M. Galassi +5
The mining of Virtual Observatories (VOs) is becoming a powerful new method for discovery in astronomy. Here we report on the development of SkyDOT (Sky Database for Objects in the…
Real-Time Detection of Optical Transients with RAPTOR
Konstantin Borozdin, Steven Brumby, Mark Galassi +6
Fast variability of optical objects is an interesting though poorly explored subject in modern astronomy. Real-time data processing and identification of transient celestial events…
The RAPTOR Experiment: A System for Monitoring the Optical Sky in Real Time
W. T. Vestrand, K. Borozdin, S. Brumby +10
The Rapid Telescopes for Optical Response (RAPTOR) experiment is a spatially distributed system of autonomous robotic telescopes that is designed to monitor the sky for optical tra…