Astrophysics - Astrophysics of Galaxies

Astro2020 Science White Paper: Are Supernovae the Dust Producer in the Early Universe?

Whether supernovae are a significant source of dust has been a long- standing debate. The large quantities of dust observed in high- redshift galaxies raise a fundamental question as to the origin of dust in the Universe since stars cannot have …

Mapping the Interstellar Reddening and Extinction toward Baadetextquoterights Window Using Minimum Light Colors of ab-type RR Lyrae Stars: Revelations from the De-reddened Color-Magnitude Diagrams

We have obtained repeated images of six fields toward the Galactic bulge in five passbands (u, g, r, i, z) with the DECam imager on the Blanco 4 m telescope at CTIO. From more than 1.6 billion individual photometric measurements in the field centered …

A Near-infrared Period-Luminosity Relation for Miras in NGC 4258, an Anchor for a New Distance Ladder

We present year-long, near-infrared (NIR) Hubble Space Telescope (HST) WFC3 observations of Mira variables in the water megamaser host galaxy NGC 4258. Miras are asymptotic giant branch variables that can be divided into oxygen- (O-) and carbon- (C-) …

Illuminating gravitational waves: A concordant picture of photons from a neutron star merger

Merging neutron stars offer an excellent laboratory for simultaneously studying strong-field gravity and matter in extreme environments. We establish the physical association of an electromagnetic counterpart (EM170817) with gravitational waves …

The host galaxies and explosion sites of long-duration gamma ray bursts: Hubble Space Telescope near-infrared imaging

We present the results of a Hubble Space Telescope WFC3/F160W Snapshot survey of the host galaxies of 39 long-duration gamma-ray bursts (LGRBs) at z < 3. We have non-detections of hosts at the locations of four bursts. Sufficient accuracy to …

The SAMI Galaxy Survey: the link between angular momentum and optical morphology

We investigate the relationship between stellar and gas specific angular momentum j, stellar mass M$_*$ and optical morphology for a sample of 488 galaxies extracted from the Sydney-AAO Multi- object Integral field Galaxy Survey. We find that j, …

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 …