Search Publications
Mapping the Stellar Halo with the H3 Spectroscopic Survey
Conroy, Charlie; Johnson, Benjamin D.; Berlind, Perry +12 more
Modern theories of galaxy formation predict that the Galactic stellar halo was hierarchically assembled from the accretion and disruption of smaller systems. This hierarchical assembly is expected to produce a high degree of structure in the combined phase and chemistry space; this structure should provide a relatively direct probe of the accretio…
Half-mass Radii for ∼7000 Galaxies at 1.0 ≤ z ≤ 2.5: Most of the Evolution in the Mass-Size Relation Is Due to Color Gradients
Barro, Guillermo; Kriek, Mariska; Price, Sedona H. +1 more
Radial mass-to-light ratio gradients cause the half-mass and half-light radii of galaxies to differ, potentially biasing studies that use half-light radii. Here we present the largest catalog to date of galaxy half-mass radii at z > 1: 7006 galaxies in the CANDELS fields at 1.0 ≤ z ≤ 2.5. The sample includes both star-forming and quiescent gala…
The Chemical Evolution of Carbon, Nitrogen, and Oxygen in Metal-poor Dwarf Galaxies
McQuinn, Kristen B. W.; Skillman, Evan D.; Erb, Dawn K. +2 more
Ultraviolet nebular emission lines are important for understanding the time evolution and nucleosynthetic origins of their associated elements, but the underlying trends of their relative abundances are unclear. We present UV spectroscopy of 20 nearby low-metallicity, high-ionization dwarf galaxies obtained using the Hubble Space Telescope. Buildi…
First Identification of 10 kpc [C II] 158 µm Halos around Star-forming Galaxies at z = 5-7
Ouchi, Masami; Ivison, R. J.; Fujimoto, Seiji +7 more
We report the discovery of 10 kpc [C II] 158 µm halos surrounding star-forming galaxies in the early universe. We choose deep Atacama Large Millimeter/submillimeter Array data for 18 galaxies, each with a star formation rate of ≃10-70 M ⊙ with no signature of an active galactic nucleus whose [C II] lines are individually detected …
Constraining the Metallicities, Ages, Star Formation Histories, and Ionizing Continua of Extragalactic Massive Star Populations
Dahle, H.; Rigby, J. R.; Sharon, K. +4 more
We infer the properties of massive star populations using the far-ultraviolet stellar continua of 61 star-forming galaxies: 42 at low redshift observed with the Hubble Space Telescope and 19 at z ∼ 2 from the MEGaSaURA sample. We fit each stellar continuum with a linear combination of up to 50 single-age and single-metallicity STARBURST99 models. …
Rotation Curve of the Milky Way from Classical Cepheids
Udalski, Andrzej; Mróz, Przemek; Szymański, Michał K. +7 more
Flat rotation curves of spiral galaxies are considered as an evidence for dark matter, but the rotation curve of the Milky Way is difficult to measure. Various objects were used to track the rotation curve in the outer parts of the Galaxy, but most studies rely on incomplete kinematical information and inaccurate distances. Here, we use a sample o…
Late-time UV Observations of Tidal Disruption Flares Reveal Unobscured, Compact Accretion Disks
Brown, Thomas M.; Fruchter, Andrew S.; Stone, Nicholas C. +3 more
The origin of thermal optical and UV emission from stellar tidal disruption flares (TDFs) remains an open question. We present Hubble Space Telescope far-UV (FUV) observations of eight optical/UV-selected TDFs 5-10 yr post-peak. Six sources are cleanly detected, showing point-like FUV emission ({10}41.5{--42.5} {erg} {{{s}}}-1
The Next Generation Virgo Cluster Survey. XXIII. Fundamentals of Nuclear Star Clusters over Seven Decades in Galaxy Mass
Emsellem, Eric; Liu, Chengze; Cuillandre, Jean-Charles +25 more
Using deep, high-resolution optical imaging from the Next Generation Virgo Cluster Survey, we study the properties of nuclear star clusters (NSCs) in a sample of nearly 400 quiescent galaxies in the core of Virgo with stellar masses 105 ≲ {\text{}}{M}* /{\text{}}{M}⊙ ≲ 1012. The nucleation fraction reac…
The Atmospheric Circulation of Ultra-hot Jupiters
Tan, Xianyu; Komacek, Thaddeus D.
Recent observations of ultra-hot Jupiters with dayside temperatures in excess of 2500 K have found evidence for new physical processes at play in their atmospheres. In this work, we investigate the effects of the dissociation of molecular hydrogen and recombination of atomic hydrogen on the atmospheric circulation of ultra-hot Jupiters. To do so, …
Inferred Evidence for Dark Matter Kinematic Substructure with SDSS-Gaia
Belokurov, Vasily; Lisanti, Mariangela; Necib, Lina
We use the distribution of accreted stars in Sloan Digital Sky Survey-Gaia DR2 to demonstrate that a nontrivial fraction of the dark matter halo within galactocentric radii of 7.5-10 kpc and | z| > 2.5 {kpc} is in substructure and thus may not be in equilibrium. Using a mixture likelihood analysis, we separate the contributions of an old, isotr…