Search Publications
A Large Fraction of Hydrogen-rich Supernova Progenitors Experience Elevated Mass Loss Shortly Prior to Explosion
Cenko, S. Bradley; Duev, Dmitry A.; Riddle, Reed +45 more
Spectroscopic detection of narrow emission lines traces the presence of circumstellar mass distributions around massive stars exploding as core-collapse supernovae. Transient emission lines disappearing shortly after the supernova explosion suggest that the material spatial extent is compact and implies an increased mass loss shortly prior to expl…
The Parallax of ω Centauri Measured from Gaia EDR3 and a Direct, Geometric Calibration of the Tip of the Red Giant Branch and the Hubble Constant
Casertano, Stefano; Riess, Adam G.; Soltis, John
We use data from the ESA Gaia mission Early Data Release 3 (EDR3) to measure the trigonometric parallax of ω Cen, the first high-precision parallax measurement for the most massive globular cluster in the Milky Way. We use a combination of positional and high-quality proper motion data from EDR3 to identify over 100,000 cluster members, of which 6…
APOGEE Chemical Abundance Patterns of the Massive Milky Way Satellites
Cohen, Roger E.; Bizyaev, Dmitry; Brownstein, Joel R. +42 more
The SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey has obtained high-resolution spectra for thousands of red giant stars distributed among the massive satellite galaxies of the Milky Way (MW): the Large and Small Magellanic Clouds (LMC/SMC), the Sagittarius Dwarf Galaxy (Sgr), Fornax (Fnx), and the now fully disrupt…
The Gas Content and Stripping of Local Group Dwarf Galaxies
Price-Whelan, Adrian M.; Peek, Joshua E. G.; Putman, Mary E. +4 more
The gas content of the complete compilation of Local Group dwarf galaxies (119 within 2 Mpc) is presented using H I survey data. Within the virial radius of the Milky Way (224 kpc here), 53 of 55 dwarf galaxies are devoid of gas to limits of MH I < 104 M⊙. Within the virial radius of M31 (266 kpc), 27 of 30 dwar…
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…