Search Publications
Revisiting the Integrated Star Formation Law. II. Starbursts and the Combined Global Schmidt Law
Kennicutt, Robert C., Jr.; De Los Reyes, Mithi A. C.
We compile observations of molecular gas contents and infrared-based star formation rates (SFRs) for 112 circumnuclear star-forming regions, in order to reinvestigate the form of the disk-averaged Schmidt surface density star-formation law in starbursts. We then combine these results with total gas and SFR surface densities for 153 nearby nonstarb…
ASASSN-14ko is a Periodic Nuclear Transient in ESO 253-G003
Holoien, Thomas W. -S.; Vallely, Patrick J.; Auchettl, Katie +24 more
We present the discovery that ASASSN-14ko is a periodically flaring active galactic nucleus at the center of the galaxy ESO 253-G003. At the time of its discovery by the All-Sky Automated Survey for Supernovae (ASAS-SN), it was classified as a supernova close to the nucleus. The subsequent 6 yr of V- and g-band ASAS-SN observations revealed that A…
The 60 pc Environment of FRB 20180916B
Kaspi, Victoria M.; Tendulkar, Shriharsh P.; Gil de Paz, Armando +18 more
Fast radio burst FRB 20180916B in its host galaxy SDSS J015800.28+654253.0 at 149 Mpc is by far the closest-known FRB with a robust host galaxy association. The source also exhibits a 16.35 day period in its bursting. Here we present optical and infrared imaging as well as integral field spectroscopy observations of FRB 20180916B with the WFC3 cam…
Observational Constraints on the Physical Properties of Interstellar Dust in the Post-Planck Era
Draine, B. T.; Hensley, Brandon S.
We present a synthesis of the astronomical observations constraining the wavelength-dependent extinction, emission, and polarization from interstellar dust from UV to microwave wavelengths on diffuse Galactic sight lines. Representative solid-phase abundances for those sight lines are also derived. Given the sensitive new observations of polarized…
New Observational Constraints on the Winds of M dwarf Stars
Redfield, Seth; Drake, Jeremy J.; Youngblood, Allison +8 more
High-resolution UV spectra of stellar H I Lyα lines from the Hubble Space Telescope (HST) provide observational constraints on the winds of coronal main-sequence stars, thanks to an astrospheric absorption signature created by the interaction between the stellar winds and the interstellar medium. We report the results of a new HST survey of M dwar…
Radiation Hydrodynamics of Turbulent H II Regions in Molecular Clouds: A Physical Origin of LyC Leakage and the Associated Lyα Spectra
Kakiichi, Koki; Gronke, Max
We examine Lyman continuum (LyC) leakage through H II regions regulated by turbulence and radiative feedback in a giant molecular cloud in the context of fully coupled radiation hydrodynamics (RHD). The physical relations of the LyC escape with H I covering fraction, kinematics, ionizing photon production efficiency, and emergent Lyα line profiles…
Possible X-Ray Quasi-periodic Eruptions in a Tidal Disruption Event Candidate
Miniutti, Giovanni; Kara, Erin; Giustini, Margherita +3 more
X-ray quasi-periodic eruptions (QPEs) are a recently discovered phenomenon associated with supermassive black holes at the centers of galaxies. They are high-amplitude soft X-ray flares that recur on timescales of hours, but what causes these flares remains uncertain. In the two years since their original discovery, four known QPE-hosting galaxies…
I Spy Transits and Pulsations: Empirical Variability in White Dwarfs Using Gaia and the Zwicky Transient Facility
Hermes, J. J.; Bell, Keaton J.; Montgomery, M. H. +13 more
We present a novel method to detect variable astrophysical objects and transient phenomena using anomalous excess scatter in repeated measurements from public catalogs of Gaia DR2 and Zwicky Transient Facility (ZTF) DR3 photometry. We first provide a generalized, all-sky proxy for variability using only Gaia DR2 photometry, calibrated to white dwa…
AGN STORM 2. I. First results: A Change in the Weather of Mrk 817
Gorjian, Varoujan; Treu, Tommaso; Kaspi, Shai +71 more
We present the first results from the ongoing, intensive, multiwavelength monitoring program of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part, selected for its historically unobscured nature, we discovered that the X-ray spectrum is highly absorbed, and there are new blueshifted, broad, and narrow UV absorp…
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) Survey Design, Reductions, and Detections
Ono, Yoshiaki; Ouchi, Masami; Papovich, Casey +60 more
We describe the survey design, calibration, commissioning, and emission-line detection algorithms for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The goal of HETDEX is to measure the redshifts of over a million Lyα emitting galaxies between 1.88 < z < 3.52, in a 540 deg2 area encompassing a comoving volume of 10.9 …