Search Publications
Tidal Distortions in NGC1052-DF2 and NGC1052-DF4: Independent Evidence for a Lack of Dark Matter
van Dokkum, Pieter; Abraham, Roberto; Pasha, Imad +11 more
Two ultra-diffuse galaxies in the same group, NGC1052-DF2 and NGC1052-DF4, have been found to have little or no dark matter and to host unusually luminous globular cluster populations. Such low-mass diffuse objects in a group environment are easily disrupted and are expected to show evidence of tidal distortions. In this work, we present deep new …
Slow Star Formation in the Milky Way: Theory Meets Observations
Ostriker, Eve C.; Evans, Neal J.; Kim, Jeong-Gyu
The observed star formation rate of the Milky Way can be explained by applying a metallicity-dependent factor to convert CO luminosity to molecular gas mass and a star formation efficiency per freefall time that depends on the virial parameter of a molecular cloud. These procedures also predict the trend of star formation rate surface density with…
Post-starburst Galaxies in the Centers of Intermediate-redshift Clusters
Richard, Johan; Mingozzi, Matilde; Fritz, Jacopo +17 more
We present results from MUSE spatially resolved spectroscopy of 21 post-starburst galaxies in the centers of eight clusters from z ~ 0.3 to z ~ 0.4. We measure spatially resolved star formation histories (SFHs), the time since quenching (t Q ), and the fraction of stellar mass assembled in the past 1.5 Gyr (µ 1.5). The…
Effects of UV Stellar Spectral Uncertainty on the Chemistry of Terrestrial Atmospheres
Youngblood, Allison; Kempton, Eliza M. -R.; Arney, Giada +2 more
The upcoming deployment of the James Webb Space Telescope will dramatically advance our ability to characterize exoplanet atmospheres, both in terms of precision and sensitivity to smaller and cooler planets. Disequilibrium chemical processes dominate these cooler atmospheres, requiring accurate photochemical modeling of such environments. The hos…
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…