Showing 2018 · astro-ph.GAShow all

79 papers · 2 filters

astro-ph.GA2018★ 96 cited

The Spatial Relation between Young Star Clusters and Molecular Clouds in M 51 with LEGUS

K. Grasha, D. Calzetti, A. Adamo +21

We present a study correlating the spatial locations of young star clusters with those of molecular clouds in NGC~5194, in order to investigate the timescale over which clusters se…

astro-ph.GA2018★ 49 cited

Accretion Disk Size Measurement and Time Delays in the Lensed Quasar WFI 2033-4723

Christopher W. Morgan, Gregory E. Hyer, Vivien Bonvin +5

We present 13 seasons of -band photometry of the quadruply-lensed quasar WFI 2033-4723 from the 1.3m SMARTS telescope at CTIO and the 1.2m Euler Swiss Telescope at La Silla, in…

astro-ph.GA2018★ 34 cited

APOGEE [C/N] Abundances Across the Galaxy: Migration and Infall from Red Giant Ages

Sten Hasselquist, Jon A. Holtzman, Matthew Shetrone +14

We present [C/N]-[Fe/H] abundance trends from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey, Data Release 14 (DR14), for red giant branch stars…

astro-ph.GA2018★ 5 cited

LSST Cadence Optimization White Paper in Support of Observations of Unresolved Tidal Stellar Streams in Galaxies beyond the Local Group

Seppo Laine, David Martinez-Delgado, Ignacio Trujillo +11

Deep observations of faint surface brightness stellar tidal streams in external galaxies with LSST are addressed in this White Paper contribution. We propose using the Wide--Fast--…

astro-ph.GA2018★ 54 cited

Anomalously low metallicity regions in MaNGA star-forming galaxies: Accretion Caught in Action?

Hsiang-Chih Hwang, Jorge K. Barrera-Ballesteros, Timothy M. Heckman +14

We use data from 1222 late-type star-forming galaxies in the SDSS IV MaNGA survey to identify regions in which the gas-phase metallicity is anomalously-low compared to expectations…

astro-ph.GA2018★ 48 cited

Space Telescope and Optical Reverberation Mapping Project. X. Understanding the Absorption-Line Holiday in NGC 5548

M. Dehghanian, G. J. Ferland, G. A. Kriss +27

The flux variations in the emission lines in active galactic nuclei (AGNs) are driven by variations in the ionizing continuum flux --which are usually reflected in the observable U…

astro-ph.GA2018★ 59 cited

Chemical Abundance Analysis of Tucana III, the Second -process Enhanced Ultra-Faint Dwarf Galaxy

J. L. Marshall, T. Hansen, J. D. Simon +56

We present a chemical abundance analysis of four additional confirmed member stars of Tucana III, a Milky Way satellite galaxy candidate in the process of being tidally disrupted a…

astro-ph.GA2018★ 35 cited

The Origin of Interstellar Turbulence in M33

Dyas Utomo, Leo Blitz, Edith Falgarone

We utilize the multi-wavelength data of M33 to study the origin of turbulence in its interstellar medium. We find that the HI turbulent energy surface density inside 8 kpc is $\sim…

astro-ph.GA2018★ 19 cited

Candidate Massive Galaxies at in the Dark Energy Survey

Pierandrea Guarnieri, Claudia Maraston, Daniel Thomas +52

Using stellar population models, we predicted that the Dark Energy Survey (DES) - due to its special combination of area (5000 deg. sq.) and depth () - would be in the po…

astro-ph.GA2018★ 261 cited

Spatially resolved rotation of the broad-line region of a quasar at sub-parsec scale

GRAVITY Collaboration, E. Sturm, J. Dexter +32

The broadening of atomic emission lines by high-velocity motion of gas near accreting supermassive black holes is an observational hallmark of quasars. Observations of broad emissi…

astro-ph.GA2018★ 43 cited

Do Spectroscopic Dense Gas Fractions Track Molecular Cloud Surface Densities?

Molly J. Gallagher, Adam K. Leroy, Frank Bigiel +22

We use ALMA and IRAM 30-m telescope data to investigate the relationship between the spectroscopically-traced dense gas fraction and the cloud-scale (120 pc) molecular gas surface…

astro-ph.GA2018★ 73 cited

APOGEE DR14/DR15 Abundances in the Inner Milky Way

G. Zasowski, M. Schultheis, S. Hasselquist +14

We present an overview of the distributions of 11 elemental abundances in the Milky Way's inner regions, as traced by APOGEE stars released as part of SDSS Data Release 14/15 (DR14…

astro-ph.GA2018★ 18 cited

The z=0.54 LoBAL Quasar SDSS J085053.12+445122.5: II. The Nature of Partial Covering in the Broad-Absorption-Line Outflow

Karen M. Leighly, Donald M. Terndrup, Adrian B. Lucy +5

It has been known for 20 years that the absorbing gas in broad absorption line quasars does not completely cover the continuum emission region, and that partial covering must be ac…

astro-ph.GA2018★ 105 cited

Finding high-redshift strong lenses in DES using convolutional neural networks

C. Jacobs, T. Collett, K. Glazebrook +63

We search Dark Energy Survey (DES) Year 3 imaging data for galaxy-galaxy strong gravitational lenses using convolutional neural networks. We generate 250,000 simulated lenses at re…

astro-ph.GA2018★ 64 cited

Quasar Accretion Disk Sizes from Continuum Reverberation Mapping in the DES Standard Star Fields

Zhefu Yu, Paul Martini, T. M. Davis +72

Measurements of the physical properties of accretion disks in active galactic nuclei are important for better understanding the growth and evolution of supermassive black holes. We…

astro-ph.GA2018★ 143 cited

Chemical Cartography with APOGEE: Multi-element abundance ratios

David H. Weinberg, Jon A. Holtzman, Sten Hasselquist +25

We map the trends of elemental abundance ratios across the Galactic disk, spanning R = 3-15 kpc and midplane distance |Z|= 0-2 kpc, for 15 elements in a sample of 20,485 stars meas…

astro-ph.GA2018★ 30 cited

HST/COS observations of the newly discovered obscuring outflow in NGC 3783

G. A. Kriss, M. Mehdipour, J. S. Kaastra +24

To understand the nature of transient obscuring outflows in active galactic nuclei, we observed the Seyfert 1 galaxy NGC 3783 on two occasions in December 2016 triggered by Swift m…

astro-ph.GA2018★ 3 cited

Discovery of two quasars at from the OGLE Survey

Szymon Kozłowski, Eduardo Bañados, A. Udalski +16

We have used deep Optical Gravitational Lensing Experiment (OGLE-IV) images ( mag, mag at ) of the Magellanic System, encompassing an area of $\s…

astro-ph.GA2018★ 48 cited

The Changing-Look Quasar Mrk 590 is Awakening

S. Mathur, K. D. Denney, A. Gupta +9

Mrk 590 was originally classified as a Seyfert 1 galaxy, but then it underwent dramatic changes: the nuclear luminosity dropped by over two orders of magnitude and the broad emissi…

astro-ph.GA2018★ 16 cited

The Robustness of Cosmological Hydrodynamic Simulation Predictions to Changes in Numerics and Cooling Physics

Shuiyao Huang, Neal Katz, Romeel Davé +8

We test and improve the numerical schemes in our smoothed particle hydrodynamics (SPH) code for cosmological simulations, including the pressure-entropy formulation (PESPH), a time…

astro-ph.GA2018★ 31 cited

Evidence for massive warm-hot circumgalactic medium around NGC 3221

Sanskriti Das, Smita Mathur, Anjali Gupta +3

We report a 3.4 detection of the warm-hot, massive, extended circumgalactic medium (CGM) around an L star-forming spiral galaxy NGC 3221, using deep Suzaku observations.…

astro-ph.GA2018★ 152 cited

Rotation curve of the Milky Way from Classical Cepheids

P. Mroz, A. Udalski, D. M. Skowron +7

Flat rotation curves of spiral galaxies are considered as an evidence for dark matter, but the rotation curve of the Milky Way is difficult to measure. Various objects were used to…

astro-ph.GA2018★ 40 cited

The Relative Specific Type Ia Supernovae Rate From Three Years of ASAS-SN

J. S. Brown, K. Z. Stanek, T. W. -S. Holoien +10

We analyze the 476 SN Ia host galaxies from the All-Sky Automated Survey for Supernova (ASAS-SN) Bright Supernova Catalogs to determine the observed relative Type Ia supernova (SN)…

astro-ph.GA2018★ 45 cited

The Spatially Resolved Dust-to-Metals Ratio in M101

I-Da Chiang, Karin M. Sandstrom, Jérémy Chastenet +3

The dust-to-metals ratio describes the fraction of the heavy elements contained in dust grains, and its variation provides key insights into the life cycle of dust. We measure the…