Search Publications
Weak Mass Loss from the Red Supergiant Progenitor of the Type II SN 2021yja
Kilpatrick, Charles D.; Foley, Ryan J.; Pan, Yen-Chen +56 more
We present high-cadence optical, ultraviolet (UV), and near-infrared data of the nearby (D ≈ 23 Mpc) Type II supernova (SN) 2021yja. Many Type II SNe show signs of interaction with circumstellar material (CSM) during the first few days after explosion, implying that their red supergiant (RSG) progenitors experience episodic or eruptive mass loss. …
Constraining Black Hole Natal Kicks with Astrometric Microlensing
Andrews, Jeff J.; Kalogera, Vicky
Multiple pieces of evidence suggest that neutron stars receive large kicks when formed from the remnant of a collapsing star. However, the evidence for whether black holes (BHs) receive natal kicks is less clear, reliant on weak constraints from the analysis of BH X-ray binaries and massive runaway and walkaway stars. Here we show, for the first t…
The Origin of Weakened Magnetic Braking in Old Solar Analogs
Ayres, Thomas R.; Kochukhov, Oleg; Stassun, Keivan G. +10 more
The rotation rates of main-sequence stars slow over time as they gradually lose angular momentum to their magnetized stellar winds. The rate of angular momentum loss depends on the strength and morphology of the magnetic field, the mass-loss rate, and the stellar rotation period, mass, and radius. Previous observations suggested a shift in magneti…
The Stellar Metallicities of Massive Quiescent Galaxies at 1.0 < z < 1.3 from KMOS + VANDELS
Castellano, Marco; Hathi, Nimish P.; Pentericci, Laura +18 more
We present a rest-frame UV-optical (λ = 2500-6400 Å) stacked spectrum representative of massive quiescent galaxies at 1.0 < z < 1.3 with log(M */M ⊙) > 10.8. The stack is constructed using VANDELS survey data, combined with new KMOS observations. We apply two independent full-spectral-fitting approaches, measuring a …
Sun-as-a-star Analyses of Various Solar Active Events Using Hα Spectral Images Taken by SMART/SDDI
Namekata, Kosuke; Ichimoto, Kiyoshi; Ishii, Takako T. +2 more
Sun-as-a-star analyses in which observational data is spatially integrated are useful for interpreting stellar data. For future applications to stellar observations, we performed Sun-as-a-star analyses of Hα spectra for various active events on the Sun, not only for flares and filament eruptions/surges on the solar disk, but also for eruptions of …
ALMA Lensing Cluster Survey: ALMA-Herschel Joint Study of Lensed Dusty Star-forming Galaxies across z ≃ 0.5 - 6
Pérez-González, Pablo G.; Koekemoer, Anton M.; Smail, Ian +25 more
We present an ALMA-Herschel joint analysis of sources detected by the ALMA Lensing Cluster Survey (ALCS) at 1.15 mm. Herschel/PACS and SPIRE data at 100-500 µm are deblended for 180 ALMA sources in 33 lensing cluster fields that are detected either securely (141 sources; in our main sample) or tentatively at S/N ≥ 4 with cross-matched HST/Sp…
Surface Brightness Profile of Lyman-α Halos out to 320 kpc in HETDEX
Ouchi, Masami; Finkelstein, Steven L.; Schneider, Donald P. +18 more
We present the median-stacked Lyman-α (Lyα) surface brightness profiles of 968 spectroscopically selected Lyα emitting galaxies (LAEs) at redshifts 1.9 < z < 3.5 in the early data of the Hobby-Eberly Telescope Dark Energy Experiment. The selected LAEs are high-confidence Lyα detections with high signal-to-noise ratios observed with good seei…
A New Era of Intracluster Light Studies with JWST
Trujillo, Ignacio; Montes, Mireia
Still largely unexplored, the diffuse light in clusters of galaxies traces the past and ongoing buildup of these massive structures. Here we present the first comprehensive study of the intracluster light (ICL) of the cluster SMACS J0723.3-7327 (z = 0.39) using the JWST Early Release Observations. These deep and high spatial resolution images allo…
The Complexity of the Cetus Stream Unveiled from the Fusion of STREAMFINDER and StarGO
Huang, Yang; Chang, Jiang; Sestito, Federico +16 more
We combine the power of two stream-searching tools, STREAMFINDER and StarGO applied to the Gaia EDR3 data, to detect stellar debris belonging to the Cetus stream system that forms a complex, nearly polar structure around the Milky Way. In this work, we find the southern extensions of the northern Cetus stream as the Palca stream and a new southern…
A Speed Bump: SN 2021aefx Shows that Doppler Shift Alone Can Explain Early Excess Blue Flux in Some Type Ia Supernovae
Suntzeff, N. B.; Galbany, L.; Brown, P. J. +17 more
We present early-time photometric and spectroscopic observations of the Type Ia supernova (SN Ia) 2021aefx. The early-time u-band light curve shows an excess flux when compared to normal SNe Ia. We suggest that the early excess blue flux may be due to a rapid change in spectral velocity in the first few days post explosion, produced by the emissio…