Search Publications
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 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…
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 …
Accurate distances to Galactic globular clusters through a combination of Gaia EDR3, HST, and literature data
Baumgardt, H.; Vasiliev, E.
We have derived accurate distances to Galactic globular clusters by combining data from the Gaia Early Data Release 3 (EDR3) with distances based on Hubble Space Telescope (HST) data and literature-based distances. We determine distances either directly from the Gaia EDR3 parallaxes, or kinematically by combining line-of-sight velocity dispersion …
Refining the Transit-timing and Photometric Analysis of TRAPPIST-1: Masses, Radii, Densities, Dynamics, and Ephemerides
Triaud, Amaury H. M. J.; Foreman-Mackey, Daniel; Meadows, Victoria S. +32 more
We have collected transit times for the TRAPPIST-1 system with the Spitzer Space Telescope over four years. We add to these ground-based, HST, and K2 transit-time measurements, and revisit an N-body dynamical analysis of the seven-planet system using our complete set of times from which we refine the mass ratios of the planets to the star. We next…
The MOSDEF Survey: The Evolution of the Mass-Metallicity Relation from z = 0 to z 3.3
Barro, Guillermo; Siana, Brian; Shapley, Alice E. +15 more
We investigate the evolution of galaxy gas-phase metallicity (O/H) over the range z = 0-3.3 using samples of ~300 galaxies at z ~ 2.3 and ~150 galaxies at z ~ 3.3 from the MOSDEF survey. This analysis crucially utilizes different metallicity calibrations at z ~ 0 and z > 1 to account for evolving interstellar medium (ISM) conditions. We find si…
Distances to PHANGS galaxies: New tip of the red giant branch measurements and adopted distances
Van Dyk, Schuyler D.; Kruijssen, J. M. Diederik; Leroy, Adam K. +29 more
PHANGS-HST is an ultraviolet-optical imaging survey of 38 spiral galaxies within ~20 Mpc. Combined with the PHANGS-ALMA, PHANGS-MUSE surveys and other multiwavelength data, the data set will provide an unprecedented look into the connections between young stars, H II regions, and cold molecular gas in these nearby star-forming galaxies. Accurate d…
The [O III]+H β equivalent width distribution at z ≃ 7: implications for the contribution of galaxies to reionization
Charlot, Stéphane; Chevallard, Jacopo; Stark, Daniel P. +1 more
We quantify the distribution of [O III]+H β line strengths at z ≃ 7 using a sample of 20 bright ( $\mathrm{M}_{\mathrm{UV}}^{}$ ≲ -21) galaxies. We select these systems over wide-area fields (2.3 deg2 total) using a new colour-selection that precisely selects galaxies at z ≃ 6.63-6.83, a redshift range where blue Spitzer/IRAC [3.6]-[4.5…