Search Publications

On the Stellar Populations of Galaxies at z = 9-11: The Growth of Metals and Stellar Mass at Early Times
DOI: 10.3847/1538-4357/ac4cad Bibcode: 2022ApJ...927..170T

Papovich, Casey; Finkelstein, Steven L.; Dickinson, Mark +18 more

We present a detailed stellar population analysis of 11 bright (H < 26.6) galaxies at z = 9-11 (three spectroscopically confirmed) to constrain the chemical enrichment and growth of stellar mass of early galaxies. We use the flexible Bayesian spectral energy distribution (SED) fitting code Prospector with a range of star formation histories (SF…

2022 The Astrophysical Journal
eHST 165
A time-resolved picture of our Milky Way's early formation history
DOI: 10.1038/s41586-022-04496-5 Bibcode: 2022Natur.603..599X

Xiang, Maosheng; Rix, Hans-Walter

The formation of our Milky Way can be split up qualitatively into different phases that resulted in its structurally different stellar populations: the halo and the disk components1-3. Revealing a quantitative overall picture of our Galaxy's assembly requires a large sample of stars with very precise ages. Here we report an analysis of …

2022 Nature
Gaia 163
An Isolated Stellar-mass Black Hole Detected through Astrometric Microlensing
DOI: 10.3847/1538-4357/ac739e Bibcode: 2022ApJ...933...83S

Ferguson, Henry C.; Brown, Thomas M.; Casertano, Stefano +91 more

We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). We used the Hubble Space Telescope (HST) to carry out precise astrometry of the source star of the long-duration (t E ≃ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462 (hereafter designated as …

2022 The Astrophysical Journal
Gaia eHST 158
First look with JWST spectroscopy: Resemblance among z ∼ 8 galaxies and local analogs
DOI: 10.1051/0004-6361/202244556 Bibcode: 2022A&A...665L...4S

Schaerer, D.; Marques-Chaves, R.; Brammer, G. +5 more

Deep images and near-IR spectra of galaxies in the field of the lensing cluster SMACS J0723.3−7327 were recently taken as part of the Early Release Observations (EROs) program of the James Webb Space Telescope (JWST). Among these, two NIRSpec spectra of galaxies, at z = 7.7 and at z = 8.5, were obtained, revealing, for the first time, the rest-fra…

2022 Astronomy and Astrophysics
JWST 157
The Low-redshift Lyman Continuum Survey. I. New, Diverse Local Lyman Continuum Emitters
DOI: 10.3847/1538-4365/ac5331 Bibcode: 2022ApJS..260....1F

Papovich, Casey; Finkelstein, Steven L.; Santini, Paola +44 more

The origins of Lyman continuum (LyC) photons responsible for the reionization of the universe are as of yet unknown and highly contested. Detecting LyC photons from the Epoch of Reionization is not possible due to absorption by the intergalactic medium, which has prompted the development of several indirect diagnostics to infer the rate at which g…

2022 The Astrophysical Journal Supplement Series
eHST 151
Star formation near the Sun is driven by expansion of the Local Bubble
DOI: 10.1038/s41586-021-04286-5 Bibcode: 2022Natur.601..334Z

Alves, João; Speagle, Joshua S.; Zucker, Catherine +8 more

For decades we have known that the Sun lies within the Local Bubble, a cavity of low-density, high-temperature plasma surrounded by a shell of cold, neutral gas and dust1-3. However, the precise shape and extent of this shell4,5, the impetus and timescale for its formation6,7, and its relationship to nearby star fo…

2022 Nature
Gaia 150
Fast, Slow, Early, Late: Quenching Massive Galaxies at z ∼ 0.8
DOI: 10.3847/1538-4357/ac449b Bibcode: 2022ApJ...926..134T

Barro, Guillermo; van Dokkum, Pieter; Conroy, Charlie +14 more

We investigate the stellar populations for a sample of 161 massive, mainly quiescent galaxies at <z obs> = 0.8 with deep Keck/DEIMOS rest-frame optical spectroscopy (HALO7D survey). With the fully Bayesian framework Prospector, we simultaneously fit the spectroscopic and photometric data with an advanced physical model (including …

2022 The Astrophysical Journal
eHST 141
The Global Dynamical Atlas of the Milky Way Mergers: Constraints from Gaia EDR3-based Orbits of Globular Clusters, Stellar Streams, and Satellite Galaxies
DOI: 10.3847/1538-4357/ac4d2a Bibcode: 2022ApJ...926..107M

Sharma, Sanjib; Malhan, Khyati; Ibata, Rodrigo A. +7 more

The Milky Way halo was predominantly formed by the merging of numerous progenitor galaxies. However, our knowledge of this process is still incomplete, especially in regard to the total number of mergers, their global dynamical properties and their contribution to the stellar population of the Galactic halo. Here, we uncover the Milky Way mergers …

2022 The Astrophysical Journal
Gaia 136
TESS Eclipsing Binary Stars. I. Short-cadence Observations of 4584 Eclipsing Binaries in Sectors 1-26
DOI: 10.3847/1538-4365/ac324a Bibcode: 2022ApJS..258...16P

Powell, Brian P.; Gagliano, Robert; Kristiansen, Martti H. +44 more

In this paper we present a catalog of 4584 eclipsing binaries observed during the first two years (26 sectors) of the TESS survey. We discuss selection criteria for eclipsing binary candidates, detection of hitherto unknown eclipsing systems, determination of the ephemerides, the validation and triage process, and the derivation of heuristic estim…

2022 The Astrophysical Journal Supplement Series
Gaia 136
The Low-redshift Lyman Continuum Survey. II. New Insights into LyC Diagnostics
DOI: 10.3847/1538-4357/ac61e4 Bibcode: 2022ApJ...930..126F

Papovich, Casey; Finkelstein, Steven L.; Santini, Paola +43 more

The Lyman continuum (LyC) cannot be observed at the epoch of reionization (z ≳ 6) owing to intergalactic H I absorption. To identify LyC emitters (LCEs) and infer the fraction of escaping LyC, astronomers have developed various indirect diagnostics of LyC escape. Using measurements of the LyC from the Low-redshift Lyman Continuum Survey (LzLCS), w…

2022 The Astrophysical Journal
eHST 135