Search Publications
Helium Variation in Four Small Magellanic Cloud Globular Clusters
Milone, Antonino P.; Dotter, Aaron; Lagioia, Edoardo P. +1 more
The multiple stellar populations (MPs) of the ∼11-13 Gyr old globular clusters (GCs) in our Galaxy are characterized by the different content of several light elements. These elements describe well-defined patterns like the C-N and the Na-O anticorrelations and the He-N and Na-N correlations. The discovery of MPs in Magellanic Cloud GCs opened up …
Rapid Rotation in the Kepler Field: Not a Single Star Phenomenon
Simonian, Gregory V. A.; Pinsonneault, Marc H.; Terndrup, Donald M.
Tens of thousands of rotation periods have been measured in the Kepler fields, including a substantial fraction of rapid rotators. We use Gaia parallaxes to distinguish photometric binaries (PBs; from single stars on the unevolved lower main sequence, and compare their distribution of rotation properties to those of single stars both with and with…
A Super-Earth and Sub-Neptune Transiting the Late-type M Dwarf LP 791-18
Mikal-Evans, Thomas; Latham, David W.; Tamura, Motohide +57 more
Planets occur most frequently around cool dwarfs, but only a handful of specific examples are known to orbit the latest-type M stars. Using TESS photometry, we report the discovery of two planets transiting the low-mass star called LP 791-18 (identified by TESS as TOI 736). This star has spectral type M6V, effective temperature 2960 K, and radius …
The MOSDEF Survey: Broad Emission Lines at z = 1.4-3.8
Siana, Brian; Shapley, Alice E.; Azadi, Mojegan +12 more
We present results from the MOSFIRE Deep Evolution Field survey on broad flux from the nebular emission lines Hα, [N II], [O III], Hβ, and [S II]. The sample consists of 127 star-forming galaxies at 1.37 < z < 2.61 and 84 galaxies at 2.95 < z < 3.80. We decompose the emission lines using narrow and broad Gaussian components that we def…
The Distribution of Ultra-diffuse and Ultra-compact Galaxies in the Frontier Fields
Forbes, Duncan A.; Romanowsky, Aaron J.; Abraham, Roberto +2 more
Large low-surface-brightness galaxies have recently been found to be abundant in nearby galaxy clusters. In this paper, we investigate these ultra-diffuse galaxies (UDGs) in the six Hubble Frontier Fields galaxy clusters: A2744, MACS J0416.1-2403, MACS J0717.5+3745, MACS J1149.5+2223, AS1063, and A370. These are the most massive (1-3 × 1015
Millimeter Mapping at z ∼ 1: Dust-obscured Bulge Building and Disk Growth
Übler, Hannah; Price, Sedona H.; Belli, Sirio +16 more
A randomly chosen star in today’s universe is most likely to live in a galaxy with stellar mass between the Milky Way and Andromeda. It remains uncertain, however, how the structural evolution of these bulge-disk systems proceeded. Most of the unobscured star formation we observe by building Andromeda progenitor s at 0.7 < z < 1.5 occurs in …
Testing Systematics of Gaia DR2 Parallaxes with Empirical Surface Brightness: Color Relations Applied to Eclipsing Binaries
Breuval, Louise; Gieren, Wolfgang; Pietrzyński, Grzegorz +18 more
Using a sample of 81 galactic, detached eclipsing binary stars we investigated the global zero-point shift of their parallaxes with the Gaia Data Release 2 (DR2) parallaxes. The stars in the sample lay in a distance range of 0.04-2 kpc from the Sun. The photometric parallaxes ϖ Phot of the eclipsing binaries were determined by applying …
Anatomy of a Cooling Flow: The Feedback Response to Pure Cooling in the Core of the Phoenix Cluster
Sharon, K.; Gladders, M. D.; Gaspari, M. +17 more
We present new, deep observations of the Phoenix cluster from Chandra, the Hubble Space Telescope, and the Karl Jansky Very Large Array. These data provide an order-of-magnitude improvement in depth and/or angular resolution over previous observations at X-ray, optical, and radio wavelengths. We find that the one-dimensional temperature and entrop…
The Ultracool SpeXtroscopic Survey. I. Volume-limited Spectroscopic Sample and Luminosity Function of M7-L5 Ultracool Dwarfs
Burgasser, Adam J.; Faherty, Jacqueline K.; Gagné, Jonathan +9 more
We present a volume-limited, spectroscopically verified sample of M7-L5 ultracool dwarfs (UCDs) within 25 pc. The sample contains 410 sources, of which 93% have trigonometric distance measurements (80% from Gaia DR2) and 81% have low-resolution (R ∼ 120), near-infrared (NIR) spectroscopy. We also present an additional list of 60 sources that may b…
Radial Variations in Grain Sizes and Dust Scale Heights in the Protoplanetary Disk around HD 163296 Revealed by ALMA Polarization Observations
Kataoka, Akimasa; Ohashi, Satoshi
The disk of HD 163296 shows ring and gap substructures in observations with the Atacama Large Millimeter/submillimeter Array. In addition, this is the only disk where the rings and gaps are spatially resolved in millimeter-wave polarization measurements. In this paper, we conduct radiative transfer modeling that includes self-scattering polarizati…