Search Publications
Gas-rich, Field Ultra-diffuse Galaxies Host Few Globular Clusters
Janowiecki, Steven; Sand, David J.; Leisman, Lukas +7 more
We present Hubble Space Telescope imaging of 14 gas-rich, low-surface-brightness galaxies in the field at distances of 25-36 Mpc, with mean effective radii and g-band central surface brightnesses of 1.9 kpc and 24.2 mag arcsec-2. Nine meet the standard criteria to be considered ultra-diffuse galaxies (UDGs). An inspection of point-like …
Mapping Protoplanetary Disk Vertical Structure with CO Isotopologue Line Emission
Wilner, David J.; Andrews, Sean M.; Bae, Jaehan +21 more
High-spatial-resolution observations of CO isotopologue line emission in protoplanetary disks at mid-inclinations (≈30°–75°) allow us to characterize the gas structure in detail, including radial and vertical substructures, emission surface heights and their dependencies on source characteristics, and disk temperature profiles. By combining observ…
Application of the Disk Instability Model to All Quasiperiodic Eruptions
Li, Shuang-Liang; Cao, Xinwu; Pan, Xin
After the first quasiperiodic eruption (QPE; GSN 069) was reported in 2019, four other sources have been identified as a QPE or a candidate. However, the physics behind QPEs is still unclear, although several models have been proposed. Pan et al. proposed an instability model for an accretion disk with magnetically driven outflows in the first QPE…
Minor Merger Growth in Action: JWST Detects Faint Blue Companions around Massive Quiescent Galaxies at 0.5 ≤ z ≤ 3.0
Carniani, Stefano; Übler, Hannah; D'Eugenio, Francesco +17 more
Minor mergers are thought to drive the structural evolution of massive quiescent galaxies; however, existing Hubble Space Telescope (HST) imaging is primarily sensitive to stellar mass ratios ≳1:10. Here, we report the discovery of a large population of low-mass companions within 35 kpc of known $\mathrm{log}{M}_{* }/{M}_{\odot }\gtrsim 10.5$ quie…
The Hubble Space Telescope Survey of M31 Satellite Galaxies. II. The Star Formation Histories of Ultrafaint Dwarf Galaxies
Lewis, Geraint F.; Cooper, M. C.; Brown, Thomas M. +34 more
We present the lifetime star formation histories (SFHs) for six ultrafaint dwarf (UFD; M V > - 7.0, $4.9\lt {\mathrm{log}}_{10}({M}_{* }(z=0)/{M}_{\odot })\lt 5.5$ ) satellite galaxies of M31 based on deep color-magnitude diagrams constructed from Hubble Space Telescope imaging. These are the first SFHs obtained from the oldest mai…
The Quest for the Missing Dust. II. Two Orders of Magnitude of Evolution in the Dust-to-gas Ratio Resolved within Local Group Galaxies
Gordon, Karl D.; Bot, Caroline; Clark, Christopher J. R. +3 more
We explore evolution in the dust-to-gas ratio with density within four well-resolved Local Group galaxies-the LMC, SMC, M31, and M33. We do this using new Herschel maps, which restore extended emission that was missed by previous Herschel reductions. Combining this sensitivity to diffuse dust emission with excellent physical resolution allows us t…
AGN STORM 2. IV. Swift X-Ray and Ultraviolet/Optical Monitoring of Mrk 817
Kaspi, Shai; Filippenko, Alexei V.; Hall, Patrick B. +48 more
The AGN STORM 2 campaign is a large, multiwavelength reverberation mapping project designed to trace out the structure of Mrk 817 from the inner accretion disk to the broad emission line region and out to the dusty torus. As part of this campaign, Swift performed daily monitoring of Mrk 817 for approximately 15 months, obtaining observations in X-…
ALMA Reveals a Stable Rotating Gas Disk in a Paradoxical Low-mass, Ultradusty Galaxy at z = 4.274
Murphy, Eric; Brammer, Gabriel; Marchesini, Danilo +13 more
We report ALMA detections of [C II] and a dust continuum in Az9, a multiply imaged galaxy behind the Frontier Field cluster MACS J0717.5+3745. The bright [C II] emission line provides a spectroscopic redshift of z = 4.274. This strongly lensed (µ = 7 ± 1) galaxy has an intrinsic stellar mass of only 2 × 109 M ⊙ and a to…
The Low-redshift Lyman Continuum Survey: Optically Thin and Thick Mg II Lines as Probes of Lyman Continuum Escape
Henry, Alaina; Hayes, Matthew; Chisholm, John +14 more
The Mg II λλ2796, 2803 doublet has been suggested as a useful indirect indicator for the escape of Lyα and Lyman continuum (LyC) photons in local star-forming galaxies. However, studies to date have focused on small samples of galaxies with strong Mg II or strong LyC emission. Here, we present the first study of Mg II to probe a large dynamic rang…
JWST and ALMA Imaging of Dust-obscured, Massive Substructures in a Typical z ∼ 3 Star-forming Disk Galaxy
Giavalisco, Mauro; Schramm, Malte; Daddi, Emanuele +8 more
We present an identification of dust-attenuated star-forming galactic-disk substructures in a typical star-forming galaxy (SFG), UDF2, at z = 2.696. To date, substructures containing significant buildup of stellar mass and actively forming stars have yet to be found in typical (i.e., main-sequence) SFGs at z > 2. This is due to the strong dust …