Search Publications
A Test of the Cosmological Principle with Quasars
Secrest, Nathan J.; Sarkar, Subir; Mohayaee, Roya +3 more
We study the large-scale anisotropy of the universe by measuring the dipole in the angular distribution of a flux-limited, all-sky sample of 1.36 million quasars observed by the Wide-field Infrared Survey Explorer (WISE). This sample is derived from the new CatWISE2020 catalog, which contains deep photometric measurements at 3.4 and 4.6 µm f…
The Hipparcos-Gaia Catalog of Accelerations: Gaia EDR3 Edition
Brandt, Timothy D.
We present a cross-calibration of Hipparcos and Gaia EDR3 intended to identify astrometrically accelerating stars and to fit orbits to stars with faint, massive companions. The resulting catalog, the EDR3 edition of the Hipparcos-Gaia Catalog of Accelerations (HGCA), provides three proper motions with calibrated uncertainties on the EDR3 reference…
Parallax Systematics and Photocenter Motions of Benchmark Eclipsing Binaries in Gaia EDR3
Torres, Guillermo; Stassun, Keivan G.
Previous analyses of various standard candles observed by the Gaia satellite have reported statistically significant systematics in the parallaxes that have improved from ∼250 µas in the first data release (DR1) to 50-80 µas in the second data release (DR2). Here we examine the parallaxes newly reported in the Gaia early third data rel…
Compact steep-spectrum and peaked-spectrum radio sources
O'Dea, Christopher P.; Saikia, D. J.
Compact steep-spectrum (CSS) and peaked-spectrum (PS) radio sources are compact, powerful radio sources. The multi-frequency observational properties and current theories are reviewed with emphasis on developments since the earlier review of O'Dea (PASP 110:493-532, https://doi.org/10.1086/316162, 1998). There are three main hypotheses for the nat…
The California Legacy Survey. I. A Catalog of 178 Planets from Precision Radial Velocity Monitoring of 719 Nearby Stars over Three Decades
Henry, Gregory W.; Knutson, Heather A.; Kane, Stephen R. +20 more
We present a high-precision radial velocity (RV) survey of 719 FGKM stars, which host 164 known exoplanets and 14 newly discovered or revised exoplanets and substellar companions. This catalog updated the orbital parameters of known exoplanets and long-period candidates, some of which have decades-longer observational baselines than they did upon …
The CatWISE2020 Catalog
Teplitz, Harry I.; Schlegel, David J.; Mobasher, Bahram +20 more
The CatWISE2020 Catalog consists of 1,890,715,640 sources over the entire sky selected from Wide-field Infrared Survey Explorer (WISE) and NEOWISE survey data at 3.4 and 4.6 µm (W1 and W2) collected from 2010 January 7 to 2018 December 13. This data set adds two years to that used for the CatWISE Preliminary Catalog, bringing the total to si…
Observational Constraints on Black Hole Spin
Reynolds, Christopher S.
The spin of a black hole is an important quantity to study, providing a window into the processes by which a black hole was born and grew. Furthermore, spin can be a potent energy source for powering relativistic jets and energetic particle acceleration. In this review, I describe the techniques currently used to detect and measure the spins of bl…
The CHEOPS mission
Guterman, P.; Alonso, R.; Deleuil, M. +107 more
The CHaracterising ExOPlanet Satellite (CHEOPS) was selected on October 19, 2012, as the first small mission (S-mission) in the ESA Science Programme and successfully launched on December 18, 2019, as a secondary passenger on a Soyuz-Fregat rocket from Kourou, French Guiana. CHEOPS is a partnership between ESA and Switzerland with important contri…
Tango for three: Sagittarius, LMC, and the Milky Way
Erkal, Denis; Vasiliev, Eugene; Belokurov, Vasily
We assemble a catalogue of candidate Sagittarius stream members with 5D and 6D phase-space information, using astrometric data from Gaia DR2, distances estimated from RR Lyrae stars, and line-of-sight velocities from various spectroscopic surveys. We find a clear misalignment between the stream track and the direction of the reflex-corrected prope…
Cygnus X-1 contains a 21-solar mass black hole—Implications for massive star winds
Gou, Lijun; Byun, Do-Young; Bahramian, Arash +23 more
The evolution of massive stars is influenced by the mass lost to stellar winds over their lifetimes. These winds limit the masses of the stellar remnants (such as black holes) that the stars ultimately produce. We used radio astrometry to refine the distance to the black hole x-ray binary Cygnus X-1, which we found to be 2.22-0.17+…