Search Publications
Primordial black holes as a dark matter candidate
Kavanagh, Bradley J.; Green, Anne M.
The detection of gravitational waves from mergers of tens of Solar mass black hole binaries has led to a surge in interest in primordial black holes (PBHs) as a dark matter candidate. We aim to provide a (relatively) concise overview of the status of PBHs as a dark matter candidate, circa Summer 2020. First we review the formation of PBHs in the e…
The GALAH+ survey: Third data release
Lewis, Geraint F.; Ting, Yuan-Sen; Casey, Andrew R. +44 more
The ensemble of chemical element abundance measurements for stars, along with precision distances and orbit properties, provides high-dimensional data to study the evolution of the Milky Way. With this third data release of the Galactic Archaeology with HERMES (GALAH) survey, we publish 678 423 spectra for 588 571 mostly nearby stars (81.2 per cen…
Measurements of the Hubble Constant: Tensions in Perspective
Freedman, Wendy L.
Measurement of the distances to nearby galaxies has improved rapidly in recent decades. The ever-present challenge is to reduce systematic effects, especially as greater distances are probed and the uncertainties become larger. In this paper, we combine several recent calibrations of the tip of the red giant branch (TRGB) method. These calibration…
Gaia EDR3 view on galactic globular clusters
Vasiliev, Eugene; Baumgardt, Holger
We use the data from Gaia Early Data Release 3 (EDR3) to study the kinematic properties of Milky Way globular clusters. We measure the mean parallaxes and proper motions (PM) for 170 clusters, determine the PM dispersion profiles for more than 100 clusters, uncover rotation signatures in more than 20 objects, and find evidence for radial or tangen…
A million binaries from Gaia eDR3: sample selection and validation of Gaia parallax uncertainties
Rix, Hans-Walter; El-Badry, Kareem; Heintz, Tyler M.
We construct from Gaia eDR3 an extensive catalogue of spatially resolved binary stars within ≈1 kpc of the Sun, with projected separations ranging from a few au to 1 pc. We estimate the probability that each pair is a chance alignment empirically, using the Gaia catalogue itself to calculate the rate of chance alignments as a function of observabl…
Gaia Early Data Release 3. Catalogue validation
Jordi, C.; Luri, X.; Cantat-Gaudin, T. +33 more
Context. The third Gaia data release is published in two stages. The early part, Gaia EDR3, gives very precise astrometric and photometric properties for nearly two billion sources together with seven million radial velocities from Gaia DR2. The full release, Gaia DR3, will add radial velocities, spectra, light curves, and astrophysical parameters…
New Determinations of the UV Luminosity Functions from z 9 to 2 Show a Remarkable Consistency with Halo Growth and a Constant Star Formation Efficiency
Oesch, P. A.; Bouwens, R. J.; Reddy, N. +9 more
Here we provide the most comprehensive determinations of the rest-frame UV luminosity function (LF) available to date with the Hubble Space Telescope (HST) at z ~ 2-9. Essentially all of the noncluster extragalactic legacy fields are utilized, including the Hubble Ultra Deep Field, the Hubble Frontier Fields parallel fields, and all five CANDELS f…
Seventeen Tidal Disruption Events from the First Half of ZTF Survey Observations: Entering a New Era of Population Studies
Kilpatrick, Charles D.; Foley, Ryan J.; Cenko, S. Bradley +37 more
While tidal disruption events (TDEs) have long been heralded as laboratories for the study of quiescent black holes, the small number of known TDEs and uncertainties in their emission mechanism have hindered progress toward this promise. Here we present 17 new TDEs that have been detected recently by the Zwicky Transient Facility along with Swift …
PHANGS-ALMA: Arcsecond CO(2-1) Imaging of Nearby Star-forming Galaxies
Sandstrom, Karin M.; Bolatto, Alberto D.; Henshaw, Jonathan D. +69 more
We present PHANGS-ALMA, the first survey to map CO J = 2 → 1 line emission at ~1″ ~100 pc spatial resolution from a representative sample of 90 nearby (d ≲ 20 Mpc) galaxies that lie on or near the z = 0 "main sequence" of star-forming galaxies. CO line emission traces the bulk distribution of molecular gas, which is the cold, star-forming phase of…
Tidal Disruption Events
Gezari, Suvi
The concept of stars being tidally ripped apart and consumed by a massive black hole (MBH) lurking in the center of a galaxy first captivated theorists in the late 1970s. The observational evidence for these rare but illuminating phenomena for probing otherwise dormant MBHs first emerged in archival searches of the soft X-ray ROSAT All-Sky Survey …