Search Publications
C/2014 UN271 (Bernardinelli-Bernstein): The Nearly Spherical Cow of Comets
Smith, M.; Allam, S.; Annis, J. +65 more
Comet C/2014 UN271 (Bernardinelli-Bernstein), incoming from the Oort cloud, is remarkable in having the brightest (and presumably largest) nucleus of any well-measured comet and having been discovered at the heliocentric distance rh ≈ 29 au, farther than any Oort cloud comet. In this work, we describe the discovery process an…
Identifying RR Lyrae Variable Stars in Six Years of the Dark Energy Survey
Bacon, D.; Bechtol, K.; Smith, M. +67 more
We present a search for RR Lyrae stars using the full six-year data set from the Dark Energy Survey covering ∼5000 deg2 of the southern sky. Using a multistage multivariate classification and light-curve template-fitting scheme, we identify RR Lyrae candidates with a median of 35 observations per candidate. We detect 6971 RR Lyrae candi…
The Astrophysical Distance Scale. III. Distance to the Local Group Galaxy WLM Using Multiwavelength Observations of the Tip of the Red Giant Branch, Cepheids, and JAGB Stars
Madore, Barry F.; Freedman, Wendy L.; Lee, Abigail J. +3 more
The local determination of the Hubble constant sits at a crossroad. Current estimates of the local expansion rate of the universe differ by about 1.7σ, derived from the Cepheid- and TRGB-based calibrations, applied to Type Ia supernovae. To help elucidate possible sources of systematic error causing the tension, we show in this study the recently …
RELICS: Properties of z ≥ 5.5 Galaxies Inferred from Spitzer and Hubble Imaging, Including A Candidate z ∼ 6.8 Strong [O III] emitter
Ouchi, Masami; Mahler, Guillaume; Frye, Brenda L. +26 more
We present constraints on the physical properties (including stellar mass, age, and star formation rate) of 207 6 ≲ z ≲ 8 galaxy candidates from the Reionization Lensing Cluster Survey (RELICS) and Spitzer-RELICS surveys. We measure photometry using T-PHOT and perform spectral energy distribution fitting using EAzY and BAGPIPES. Of the 207 candida…
The Detection of a Hot Molecular Core in the Extreme Outer Galaxy
Shimonishi, Takashi; Furuya, Kenji; Izumi, Natsuko +1 more
Interstellar chemistry in low-metallicity environments is crucial to understand chemical processes in the past metal-poor universe. Recent studies of interstellar molecules in nearby low-metallicity galaxies have suggested that metallicity has a significant effect on the chemistry of star-forming cores. Here we report the first detection of a hot …
Big Three Dragons: A [N II] 122 µm Constraint and New Dust-continuum Detection of a z = 7.15 Bright Lyman-break Galaxy with ALMA
Fujimoto, Seiji; Inoue, Akio K.; Hashimoto, Takuya +6 more
We present new Atacama Large Millimeter/submillimeter Array Band 7 observational results of a Lyman-break galaxy at z = 7.15, B14-65666 ("Big Three Dragons"), which is an object detected in [O III] 88 µm, [C II] 158 µm, and dust continuum emission during the epoch of reionization. Our targets are the [N II] 122 µm fine-structure …
Red Supergiants in M31 and M33. I. The Complete Sample
Yang, Ming; Ren, Yi; Jiang, Biwei +3 more
The aim of this paper is to establish a complete sample of red supergiants (RSGs) in M31 and M33. The member stars of the two galaxies are selected from the near-infrared (NIR) point sources after removing the foreground dwarfs from their obvious branch in the J - H/H - K diagram with the archival photometric data taken by the UKIRT/WFCAM. This se…
Planets Across Space and Time (PAST). I. Characterizing the Memberships of Galactic Components and Stellar Ages: Revisiting the Kinematic Methods and Applying to Planet Host Stars
Huang, Yang; Dong, Subo; Liu, Chao +7 more
Over 4000 exoplanets have been identified and thousands of candidates are to be confirmed. The relations between the characteristics of these planetary systems and the kinematics, Galactic components, and ages of their host stars have yet to be well explored. To address these questions, we conduct a research project, dubbed Planets Across Space an…
Most "Young" α-rich Stars Have High Masses but are Actually Old
Xiang, Maosheng; Huang, Yang; Ting, Yuan-Sen +8 more
Recent observations have revealed a population of α-element abundances, enhanced giant stars with unexpected high masses (≳1 M ⊙) from asteroseismic analysis and spectroscopy. Assuming single-star evolution, their masses imply young ages (τ < 6 Gyr) incompatible with the canonical Galactic chemical evolution scenario. Here we study t…
VVV CL001: Likely the Most Metal-poor Surviving Globular Cluster in the Inner Galaxy
Majewski, Steven R.; Beers, Timothy C.; Minniti, Dante +11 more
We present the first high-resolution abundance analysis of the globular cluster VVV CL001, which resides in a region dominated by high interstellar reddening toward the Galactic bulge. Using H-band spectra acquired by the Apache Point Observatory Galactic Evolution Experiment, we identified two potential members of the cluster, and estimated from …