Search Publications
Consistent Calibration of the Tip of the Red Giant Branch in the Large Magellanic Cloud on the Hubble Space Telescope Photometric System and a Redetermination of the Hubble Constant
Casertano, Stefano; Riess, Adam G.; Yuan, Wenlong +2 more
We present a calibration of the tip of the red giant branch (TRGB) in the Large Magellanic Cloud (LMC) on the Hubble Space Telescope (HST)/ACS F814W system. We use archival HST observations to derive blending corrections and photometric transformations for two ground-based wide-area imaging surveys of the Magellanic Clouds. We show that these surv…
The Lyman Continuum Escape Survey: Ionizing Radiation from [O III]-strong Sources at a Redshift of 3.1
Tang, Mengtao; Stark, Daniel P.; Ellis, Richard S. +4 more
We present results from the LymAn Continuum Escape Survey (LACES), a Hubble Space Telescope (HST) program designed to characterize the ionizing radiation emerging from a sample of Lyα-emitting galaxies at redshift z ≃ 3.1. As many show intense [O III] emission characteristic of z > 6.5 star-forming galaxies, they may represent valuable low-reds…
A Catalog of Newly Identified Star Clusters in Gaia DR2
Pang, Xiaoying; Liu, Lei
We present the Star cluster Hunting Pipeline (SHiP) that can identify star clusters in Gaia second data release (DR2) data and establish a star cluster catalog for the Galactic disk. A friend-of-friend-based cluster finder method is used to identify star clusters using five-dimensional stellar parameters, l,b,\varpi ,{µ }α \cos δ …
Evidence for an Intermediate-mass Milky Way from Gaia DR2 Halo Globular Cluster Motions
van der Marel, Roeland P.; Watkins, Laura L.; Evans, N. Wyn +1 more
We estimate the mass of the Milky Way (MW) within 21.1 kpc using the kinematics of halo globular clusters (GCs) determined by Gaia. The second Gaia data release (DR2) contained a catalog of absolute proper motions (PMs) for a set of Galactic GCs and satellite galaxies. We select from the catalog only halo GCs, identifying a total of 34 GCs spannin…
Characterizing the properties of nearby molecular filaments observed with Herschel
André, Ph.; Arzoumanian, D.; Könyves, V. +8 more
Context. Molecular filaments have received special attention recently thanks to new observational results on their properties. In particular, our early analysis of filament properties from Herschel imaging data in three nearby molecular clouds revealed a narrow distribution of median inner widths centered at a characteristic value of about 0.1 pc.…
Life in the fast lane: a direct view of the dynamics, formation, and evolution of the Milky Way's bar
Bovy, Jo; Mackereth, J. Ted; Hunt, Jason A. S. +3 more
Studies of the ages, abundances, and motions of individual stars in the Milky Way provide one of the best ways to study the evolution of disc galaxies over cosmic time. The formation of the Milky Way's barred inner region in particular is a crucial piece of the puzzle of disc galaxy evolution. Using data from APOGEE and Gaia, we present maps of th…
H2O abundances and cloud properties in ten hot giant exoplanets
Madhusudhan, Nikku; Gandhi, Siddharth; Pinhas, Arazi +1 more
Transmission spectroscopy of exoplanets has the potential to provide precise measurements of atmospheric chemical abundances, in particular of hot Jupiters whose large sizes and high temperatures make them conducive to such observations. To date, several transmission spectra of hot Jupiters have revealed low amplitude features of water vapour comp…
A Second Galaxy Missing Dark Matter in the NGC 1052 Group
van Dokkum, Pieter; Romanowsky, Aaron J.; Conroy, Charlie +2 more
The ultra-diffuse galaxy NGC1052-DF2 has a very low velocity dispersion, indicating that it has little or no dark matter. Here we report the discovery of a second galaxy in this class, residing in the same group. NGC1052-DF4 closely resembles NGC1052-DF2 in terms of its size, surface brightness, and morphology; has a similar distance of {D}sb…
A three-dimensional map of the Milky Way using classical Cepheid variable stars
Udalski, Andrzej; Mróz, Przemek; Szymański, Michał K. +9 more
The Milky Way is a barred spiral galaxy, with physical properties inferred from various tracers informed by the extrapolation of structures seen in other galaxies. However, the distances of these tracers are measured indirectly and are model-dependent. We constructed a map of the Milky Way in three dimensions, based on the positions and distances …
The hidden giant: discovery of an enormous Galactic dwarf satellite in Gaia DR2
Kuehn, K.; Li, T. S.; Evans, N. W. +8 more
We report the discovery of a Milky Way satellite in the constellation of Antlia. The Antlia 2 dwarf galaxy is located behind the Galactic disc at a latitude of b ∼ 11° and spans 1.26°, which corresponds to ∼2.9 kpc at its distance of 130 kpc. While similar in spatial extent to the Large Magellanic Cloud, Antlia 2 is orders of magnitude fainter at …