Search Publications
Mass, Spin, and Ultralight Boson Constraints from the Intermediate-mass Black Hole in the Tidal Disruption Event 3XMM J215022.4-055108
Wen, Sixiang; Jonker, Peter G.; Stone, Nicholas C. +1 more
We simultaneously and successfully fit the multiepoch X-ray spectra of the tidal disruption event (TDE) 3XMM J215022.4-055108 using a modified version of our relativistic slim disk model that now accounts for angular momentum losses from radiation. We explore the effects of different disk properties and of uncertainties in the spectral hardening f…
How robustly can we constrain the low-mass end of the z ∼ 6-7 stellar mass function? The limits of lensing models and stellar population assumptions in the Hubble Frontier Fields
Charlot, Stéphane; Chevallard, Jacopo; Lehnert, Matthew D. +2 more
We present new measurements of the very low mass end of the galaxy stellar mass function (GSMF) at z ~ 6-7 computed from a rest-frame ultraviolet selected sample of dropout galaxies. These galaxies lie behind the six Hubble Frontier Field clusters and are all gravitationally magnified. Using deep Spitzer/IRAC and Hubble Space Telescope imaging, we…
The Brown Dwarf Kinematics Project (BDKP). V. Radial and Rotational Velocities of T Dwarfs from Keck/NIRSPEC High-resolution Spectroscopy
Gelino, Christopher R.; Burgasser, Adam J.; Faherty, Jacqueline K. +7 more
We report multiepoch radial velocities, rotational velocities, and atmospheric parameters for 37 T-type brown dwarfs observed with Keck/NIRSPEC. Using a Markov Chain Monte Carlo forward-modeling method, we achieve median precisions of 0.5 and 0.9 km s-1 for radial and rotational velocities, respectively. All of the T dwarfs in our sampl…
A Catalog of Potential Post-Common Envelope Binaries
Kobayashi, Chiaki; Di Stefano, Rosanne; Gao, Yan +2 more
We present a catalog containing 839 candidate post-common envelope systems. Common envelope evolution is very important in stellar astrophysics, particularly in the context of very compact and short-period binaries, including cataclysmic variables, as progenitors of, e.g., supernovae Type Ia or mergers of black holes and/or neutron stars. At the s…
Recurring Planetary Debris Transits and Circumstellar Gas around White Dwarf ZTF J0328-1219
Vanderburg, Andrew; Hermes, J. J.; Weinberger, Alycia J. +14 more
We present follow-up photometry and spectroscopy of ZTF J0328-1219, strengthening its status as a white dwarf exhibiting transiting planetary debris. Using TESS and Zwicky Transient Facility photometry, along with follow-up high-speed photometry from various observatories, we find evidence for two significant periods of variability at 9.937 and 11…
A survey of the linear polarization of directly imaged exoplanets and brown dwarf companions with SPHERE-IRDIS. First polarimetric detections revealing disks around DH Tau B and GSC 6214-210 B
Ménard, F.; Schmidt, T. O. B.; Ginski, C. +22 more
Context. Young giant planets and brown dwarf companions emit near-infrared radiation that can be linearly polarized up to several percent. This polarization can reveal the presence of an (unresolved) circumsubstellar accretion disk, rotation-induced oblateness of the atmosphere, or an inhomogeneous distribution of atmospheric dust clouds.
Aim…
Microarcsecond Astrometry: Science Highlights from Gaia
Brown, Anthony G. A.
Access to microarcsecond astrometry is now routine in the radio, infrared (IR), and optical domains. In particular, the publication of the second data release (Gaia DR2) from the Gaia mission made it possible for every astronomer to work with easily accessible, high-precision astrometry for 1.7 billion sources to twenty-first magnitude over the fu…
The first ALMA survey of protoplanetary discs at 3 mm: demographics of grain growth in the Lupus region
Guidi, G.; Testi, L.; Tazzari, M. +9 more
We present the first ALMA survey of protoplanetary discs at 3 mm, targeting 36 young stellar objects in the Lupus star-forming region with deep observations (sensitivity 20-50 $\mu$Jy beam-1) at ~0.35 arcsec resolution (~50 au). Building on previous ALMA surveys at 0.89 and 1.3 mm that observed the complete sample of Class II discs in L…
Gaia Early Data Release 3. Updated radial velocities from Gaia DR2
Smith, M.; Gosset, E.; Allende Prieto, C. +40 more
Context. Gaia's Early Third Data Release (EDR3) does not contain new radial velocities because these will be published in Gaia's full third data release (DR3), expected in the first half of 2022. To maximise the usefulness of EDR3, Gaia's second data release (DR2) sources (with radial velocities) are matched to EDR3 sources to allow their DR2 radi…
Speckle Observations of TESS Exoplanet Host Stars: Understanding the Binary Exoplanet Host Star Orbital Period Distribution
Howell, Steve B.; Winn, Joshua N.; Ciardi, David R. +5 more
We present high-resolution speckle interferometric imaging observations of TESS exoplanet host stars using the NN-EXPLORE Exoplanet and Stellar Speckle Imager instrument at the 3.5 m WIYN telescope. Eight TESS objects of interest that were originally discovered by Kepler were previously observed using the Differential Speckle Survey Instrument. Sp…