Search Publications
The CHARA Array Interferometric Program on the Multiplicity of Classical Be Stars: New Detections and Orbits of Stripped Subdwarf Companions
Gies, Douglas R.; Klement, Robert; Rivinius, Thomas +8 more
Rapid rotation and nonradial pulsations enable Be stars to build decretion disks, where the characteristic line emission forms. A major but unconstrained fraction of Be stars owe their rapid rotation to mass and angular momentum transfer in a binary. The faint, stripped companions can be helium-burning subdwarf OB-type stars (sdOBs), white dwarfs …
Cold Dark Matter and Self-interacting Dark Matter Interpretations of the Strong Gravitational Lensing Object JWST-ER1
Kong, Demao; Yang, Daneng; Yu, Hai-Bo
van Dokkum et al. reported the discovery of JWST-ER1, a strong lensing object at redshift z ≈ 2, using data from the James Webb Space Telescope. The lens mass within the Einstein ring is 5.9 times higher than the expected stellar mass from a Chabrier initial mass function, indicating a high dark matter density. In this work, we show that a cold da…
TESS Stellar Rotation up to 80 Days in the Southern Continuous Viewing Zone
van Saders, Jennifer L.; Claytor, Zachary R.; Beaton, Rachael L. +3 more
The Transiting Exoplanet Survey Satellite (TESS) mission delivers time-series photometry for millions of stars across the sky, offering a probe into stellar astrophysics, including rotation, on a population scale. However, light-curve systematics related to the satellite's 13.7 day orbit have prevented stellar rotation searches for periods longer …
Carnegie Supernova Project I and II: Measurements of H 0 Using Cepheid, Tip of the Red Giant Branch, and Surface Brightness Fluctuation Distance Calibration to Type Ia Supernovae
Gall, Christa; Ryder, Stuart D.; Morrell, Nidia +44 more
We present an analysis of Type Ia supernovae (SNe Ia) from the Carnegie Supernova Project I and II and extend the Hubble diagram from optical to near-infrared wavelengths (uBgVriYJH). We calculate the Hubble constant, H 0, using various distance calibrators: Cepheids, the tip of the red giant branch (TRGB), and surface brightness fluctu…
Expanded Sample of Small Magellanic Cloud Ultraviolet Dust Extinction Curves: Correlations between the 2175 Å Bump, q PAH, Ultraviolet Extinction Shape, and N(H I)/A(V)
Murray, Claire E.; Gordon, Karl D.; Fitzpatrick, E. L. +7 more
The Small Magellanic Cloud (SMC) shows a large variation in ultraviolet (UV) dust extinction curves, ranging from Milky Way (MW) like to significantly steeper curves with no detectable 2175 Å bump. This result is based on a sample of only nine sight lines. From Hubble Space Telescope Space Telescope Imaging Spectrograph and IUE spectra of OB stars…
Black Hole Spin Measurements in LMC X-1 and Cyg X-1 Are Highly Model Dependent
Zdziarski, Andrzej A.; Szanecki, Michał; Dewangan, Gulab +4 more
The black hole spin parameter, a *, was measured to be close to its maximum value of 1 in many accreting X-ray binaries. In particular, a * ≳ 0.9 was found in a number of studies of LMC X-1. These measurements were claimed to take into account both statistical and systematic uncertainties. We perform new measurements using a …
SMILES: A Prototype JWST Multiband Mid-infrared Survey
Shivaei, Irene; Lyu, Jianwei; Alberts, Stacey +4 more
The Mid-Infrared Instrument (MIRI) for JWST is supplied with a suite of imaging band-pass filters optimized for full spectral coverage in eight intermediate-width bands from 5 to 26 µm and a narrower one at 11.3 µm. This contrasts with previous infrared space telescopes, which generally have provided only two broad bands, one near 10 &…
Molecular Outflow in the Reionization-epoch Quasar J2054-0005 Revealed by OH 119 µm Observations
Fujimoto, Seiji; Inoue, Akio K.; Hashimoto, Takuya +8 more
Molecular outflows are expected to play a key role in galaxy evolution at high redshift. To study the impact of outflows on star formation at the epoch of reionization, we performed sensitive Atacama Large Millimeter/submillimeter Array observations of OH 119 µm toward J2054-0005, a luminous quasar at z = 6.04. The OH line is detected and ex…
Detection of X-Ray Polarization from the Blazar 1ES 1959+650 with the Imaging X-Ray Polarimetry Explorer
Ingram, Adam; Kaaret, Philip; Wu, Kinwah +142 more
Observations of linear polarization in the 2–8 keV energy range with the Imaging X-ray Polarimetry Explorer (IXPE) explore the magnetic field geometry and dynamics of the regions generating nonthermal radiation in relativistic jets of blazars. These jets, particularly in blazars whose spectral energy distribution peaks at X-ray energies, emit X-ra…
A Comprehensive Investigation of Metals in the Circumgalactic Medium of Nearby Dwarf Galaxies
McQuinn, Kristen B. W.; Burchett, Joseph N.; Putman, Mary E. +7 more
Dwarf galaxies are found to have lost most of their metals via feedback processes; however, there still lacks consistent assessment on the retention rate of metals in their circumgalactic medium (CGM). Here we investigate the metal content in the CGM of 45 isolated dwarf galaxies with M * = 106.5-9.5 M ⊙ (M 20…