Search Publications
Galactic Winds in Low-mass Galaxies
Skillman, Evan D.; van Zee, Liese; McQuinn, Kristen. B. W.
Stellar-feedback-driven outflows are predicted to play a fundamental role in the baryon cycle of low-mass galaxies. However, observational constraints of winds in nearby dwarf galaxies are limited, as outflows are transient, intrinsically low surface brightness features and thus difficult to detect. Using deep Hα observations, we search for winds …
The Cumulative Mass Profile of the Milky Way as Determined by Globular Cluster Kinematics from Gaia DR2
Eadie, Gwendolyn; Jurić, Mario
We present new mass estimates and cumulative mass profiles (CMPs) with Bayesian credible regions for the Milky Way (MW) Galaxy, given the kinematic data of globular clusters (GCs) as provided by (1) the Gaia DR2 collaboration and the HSTPROMO team, and (2) the new catalog in Vasiliev (2019). We use GCs beyond 15 kpc to estimate the CMP of the MW, …
The M101 Satellite Luminosity Function and the Halo-Halo Scatter among Local Volume Hosts
Zaritsky, D.; Crnojević, D.; Mutlu-Pakdil, B. +4 more
We have obtained deep Hubble Space Telescope (HST) imaging of 19 dwarf galaxy candidates in the vicinity of M101. Advanced Camera for Surveys HST photometry for two of these objects showed resolved stellar populations and tip of the red giant branch derived distances (D ∼ 7 Mpc) consistent with M101 group membership. The remaining 17 were found to…
The Discovery of a Gravitationally Lensed Quasar at z = 6.51
Hennawi, Joseph F.; Fan, Xiaohui; McGreer, Ian D. +17 more
Strong gravitational lensing provides a powerful probe of the physical properties of quasars and their host galaxies. A high fraction of the most luminous high-redshift quasars was predicted to be lensed due to magnification bias. However, no multiple imaged quasar was found at z > 5 in previous surveys. We report the discovery of J043947.08+16…
No Clear, Direct Evidence for Multiple Protoplanets Orbiting LkCa 15: LkCa 15 bcd are Likely Inner Disk Signals
Henning, Thomas; Currie, Thayne; Dong, Ruobing +30 more
Two studies utilizing sparse aperture-masking (SAM) interferometry and H α differential imaging have reported multiple Jovian companions around the young solar-mass star, LkCa 15 (LkCa 15 bcd): the first claimed direct detection of infant, newly formed planets (“protoplanets”). We present new near-infrared direct imaging/spectroscopy f…
Resolved UV and [C II] Structures of Luminous Galaxies within the Epoch of Reionization
Schaerer, D.; Mobasher, B.; Ferrara, A. +7 more
We present new deep ALMA and Hubble Space Telescope (HST)/WFC3 observations of MASOSA and VR7, two luminous Lyα emitters (LAEs) at z = 6.5, for which the UV continuum levels differ by a factor of four. No IR dust continuum emission is detected in either, indicating little amounts of obscured star formation and/or high dust temperatures. MASOSA, wi…
Tidal Interactions between Binary Stars Can Drive Lithium Production in Low-mass Red Giants
Hogg, David W.; Casey, Andrew R.; Rix, Hans-Walter +10 more
Theoretical models of stellar evolution predict that most of the lithium inside a star is destroyed as the star becomes a red giant. However, observations reveal that about 1% of red giants are peculiarly rich in lithium, often exceeding the amount in the interstellar medium or predicted from the big bang. With only about 150 lithium-rich giants d…
A Mass-dependent Slope of the Galaxy Size-Mass Relation out to z ∼ 3: Further Evidence for a Direct Relation between Median Galaxy Size and Median Halo Mass
Mowla, Lamiya; van Dokkum, Pieter; van der Wel, Arjen +1 more
We reassess the galaxy size-mass relation out to z ∼ 3 using a new definition of size and a sample of >29,000 galaxies from the 3D-HST, CANDELS, and COSMOS-DASH surveys. Instead of the half-light radius r 50 we use r 80, the radius containing 80% of the stellar light. We find that the r 80-M * relatio…
High Angular Resolution ALMA Images of Dust and Molecules in the SN 1987A Ejecta
Bouchet, P.; Wheeler, J. C.; Matsuura, Mikako +23 more
We present high angular resolution (∼80 mas) ALMA continuum images of the SN 1987A system, together with CO J = 2 \to 1, J = 6 \to 5, and SiO J = 5 \to 4 to J = 7 \to 6 images, which clearly resolve the ejecta (dust continuum and molecules) and ring (synchrotron continuum) components. Dust in the ejecta is asymmetric and clumpy, and overall the du…
Element Abundances: A New Diagnostic for the Solar Wind
Vourlidas, Angelos; Cranmer, Steven R.; Wood, Brian E. +11 more
We examine the different element abundances exhibited by the closed loop solar corona and the slow speed solar wind. Both are subject to the first ionization potential (FIP) effect, the enhancement in coronal abundance of elements with FIP below 10 eV (e.g., Mg, Si, Fe) with respect to high-FIP elements (e.g., O, Ne, Ar), but with subtle differenc…