Astrophysics - Astrophysics of Galaxies

The SAMI Galaxy Survey: Toward a Unified Dynamical Scaling Relation for Galaxies of All Types

We take advantage of the first data from the Sydney-AAO Multi-object Integral field Galaxy Survey to investigate the relation between the kinematics of gas and stars, and stellar mass in a comprehensive sample of nearby galaxies. We find that all 235 …

A Continuum of H- to He-rich Tidal Disruption Candidates With a Preference for E+A Galaxies

We present the results of a Palomar Transient Factory (PTF) archival search for blue transients that lie in the magnitude range between ``normal'' core-collapse and superluminous supernovae (i.e., with -21 <= M $_ R (peak)$ <= - 19). Of the six …

The host of the SN-less GRB 060505 in high resolution

The spiral host galaxy of the Swift GRB 060505 at z = 0.089 was the site of a puzzling long duration burst without an accompanying supernova. Studies of the burst environment by Thöne et al. suggested that this Gamma-ray Burst (GRB) came from the …

Probing the distance and morphology of the Large Magellanic Cloud with RR Lyrae stars

We present a Bayesian analysis of the distances to 15,040 Large Magellanic Cloud (LMC) RR Lyrae stars using $V$- and $I$-band light curves from the Optical Gravitational Lensing Experiment, in combination with new $z$-band observations from the Dark …

The Rise of SN 2014J in the Nearby Galaxy M82

We report on the discovery of SN 2014J in the nearby galaxy M82. Given its proximity, it offers the best opportunity to date to study a thermonuclear supernova (SN) over a wide range of the electromagnetic spectrum. Optical, near-IR, and mid-IR …

SN 2011ht: confirming a class of interacting supernovae with plateau light curves (Type IIn-P)

We present photometry and spectroscopy of the Type IIn supernova (SN) 2011ht, identified previously as a possible SN impostor. The light curve exhibits an abrupt transition from a well-defined ̃120 d plateau to a steep bolometric decline, plummeting …

A Study of the Diverse T Dwarf Population Revealed by WISE

We report the discovery of 87 new T dwarfs uncovered with the Wide-field Infrared Survey Explorer (WISE) and 3 brown dwarfs with extremely red near-infrared colors that exhibit characteristics of both L and T dwarfs. Two of the new T dwarfs are …

Automating Discovery and Classification of Transients and Variable Stars in the Synoptic Survey Era

The rate of image acquisition in modern synoptic imaging surveys has already begun to outpace the feasibility of keeping astronomers in the real-time discovery and classification loop. Here we present the inner workings of a framework, based on …

The Frequency of Debris Disks at White Dwarfs

We present near- and mid-infrared photometry and spectroscopy from PAIRITEL, IRTF, and Spitzer of a metallicity-unbiased sample of 117 cool, hydrogen-atmosphere white dwarfs (WDs) from the Palomar-Green survey and find five with excess radiation in …

An empirical relation between sodium absorption and dust extinction

Dust extinction and reddening are ubiquitous in astronomical observations and are often a major source of systematic uncertainty. We present here a study of the correlation between extinction in the Milky Way and the equivalent width of the Na I D …