Search Publications
Molecules with ALMA at Planet-forming Scales (MAPS). XIX. Spiral Arms, a Tail, and Diffuse Structures Traced by CO around the GM Aur Disk
Zhang, Ke; Kalas, Paul; Wilner, David J. +28 more
The concentric gaps and rings commonly observed in protoplanetary disks in millimeter continuum emission have lent the impression that planet formation generally proceeds within orderly, isolated systems. While deep observations of spatially resolved molecular emission have been comparatively limited, they are increasingly suggesting that some dis…
Molecules with ALMA at Planet-forming Scales (MAPS). XII. Inferring the C/O and S/H Ratios in Protoplanetary Disks with Sulfur Molecules
Zhang, Ke; Wilner, David J.; Ménard, François +24 more
Sulfur-bearing molecules play an important role in prebiotic chemistry and planet habitability. They are also proposed probes of chemical ages, elemental C/O ratio, and grain chemistry processing. Commonly detected in diverse astrophysical objects, including the solar system, their distribution and chemistry remain, however, largely unknown in pla…
Superflares, Chromospheric Activities, and Photometric Variabilities of Solar-type Stars from the Second-year Observation of TESS and Spectra of LAMOST
Wang, H. -F.; Yang, Ming; Tu, Zuo-Lin +1 more
In this work, 1272 superflares on 311 stars are collected from 22,539 solar-type stars from the second-year observation of the Transiting Exoplanet Survey Satellite (TESS), which almost covered the northern hemisphere of the sky. Three superflare stars contain hot Jupiter candidates or ultrashort-period planet candidates. We obtain γ = -1.76 ± 0.1…
Introducing piXedfit: A Spectral Energy Distribution Fitting Code Designed for Resolved Sources
Wu, Po-Feng; Lin, Yen-Ting; Abdurro'uf +1 more
We present piXedfit, pixelized spectral energy distribution (SED) fitting, a Python package that provides tools for analyzing spatially resolved properties of galaxies using multiband imaging data alone or in combination with integral field spectroscopy (IFS) data. It has six modules that can handle all tasks in the spatially resolved SED fitting.…
The Brown Dwarf Kinematics Project (BDKP). V. Radial and Rotational Velocities of T Dwarfs from Keck/NIRSPEC High-resolution Spectroscopy
Gelino, Christopher R.; Burgasser, Adam J.; Faherty, Jacqueline K. +7 more
We report multiepoch radial velocities, rotational velocities, and atmospheric parameters for 37 T-type brown dwarfs observed with Keck/NIRSPEC. Using a Markov Chain Monte Carlo forward-modeling method, we achieve median precisions of 0.5 and 0.9 km s-1 for radial and rotational velocities, respectively. All of the T dwarfs in our sampl…
TESS Observations of Cepheid Stars: First Light Results
Smolec, R.; Szabados, L.; Christensen-Dalsgaard, J. +33 more
We present the first analysis of Cepheid stars observed by the TESS space mission in Sectors 1-5. Our sample consists of 25 pulsators: ten fundamental mode, three overtone and two double-mode classical Cepheids, plus three type II and seven anomalous Cepheids. The targets were chosen from fields with different stellar densities, both from the Gala…
Stellar Metallicities from SkyMapper Photometry. II. Precise Photometric Metallicities of ∼280,000 Giant Stars with [Fe/H] < -0.75 in the Milky Way
Frebel, Anna; Mardini, Mohammad K.; Chiti, Anirudh +3 more
The Milky Way's metal-poor stars are nearby ancient objects that are used to study early chemical evolution and the assembly and structure of the Milky Way. Here we present reliable metallicities of ∼280,000 stars with -3.75 ≲ [Fe/H] ≲ -0.75 down to g = 17 derived using metallicity-sensitive photometry from the second data release of the SkyMapper…
The Magellan-TESS Survey. I. Survey Description and Midsurvey Results
Butler, R. Paul; Vanderburg, Andrew; Latham, David W. +67 more
Kepler revealed that roughly one-third of Sunlike stars host planets orbiting within 100 days and between the size of Earth and Neptune. How do these planets form, what are they made of, and do they represent a continuous population or multiple populations? To help address these questions, we began the Magellan-TESS Survey (MTS), which uses Magell…
Infrared Surface Brightness Fluctuation Distances for MASSIVE and Type Ia Supernova Host Galaxies
Ma, Chung-Pei; Greene, Jenny E.; Garnavich, Peter M. +9 more
We measured high-quality surface brightness fluctuation (SBF) distances for a sample of 63 massive early-type galaxies using the WFC3/IR camera on the Hubble Space Telescope. The median uncertainty on the SBF distance measurements is 0.085 mag, or 3.9% in distance. Achieving this precision at distances of 50-100 Mpc required significant improvemen…
591 High-velocity Stars in the Galactic Halo Selected from LAMOST DR7 and Gaia DR2
Zhao, Gang; Xiang, Maosheng; Ting, Yuan-Sen +14 more
In this paper, we report 591 high-velocity star candidates (HiVelSCs) selected from over 10 million spectra of Data Release 7 (DR7) of the Large Sky Area Multi-object Fiber Spectroscopic Telescope and the second Gaia data release, with three-dimensional velocities in the Galactic rest frame larger than 445 km s-1. We show that at least …