Search Publications
The Star-forming Main Sequence of the Host Galaxies of Low-redshift Quasars
Ho, Luis C.; Zhuang, Ming-Yang
We investigate the star-forming main sequence of the host galaxies of a large, well-defined sample of 453 redshift ~0.3 quasars with previously available star formation rates by deriving stellar masses from modeling their broadband (grizy) spectral energy distribution. We perform two-dimensional, simultaneous, multi-filter decomposition of Pan-STA…
CLEAR: Boosted Lyα Transmission of the Intergalactic Medium in UV-bright Galaxies
Papovich, Casey; Finkelstein, Steven L.; Cleri, Nikko J. +11 more
Reionization is an inhomogeneous process, thought to begin in small ionized bubbles of the intergalactic medium (IGM) around overdense regions of galaxies. Recent Lyα studies during the epoch of reionization show evidence that ionized bubbles formed earlier around brighter galaxies, suggesting higher IGM transmission of Lyα from these galaxies. We…
RR Lyrae-based Distances for 39 Nearby Dwarf Galaxies Calibrated to Gaia eDR3
El-Badry, Kareem; Weisz, Daniel R.; Nagarajan, Pranav
We provide uniform RR Lyrae-based distances to 39 dwarf galaxies in and around the Local Group. We determine distances based on a Bayesian hierarchical model that uses periods and magnitudes of published RR Lyrae in dwarf galaxies and is anchored to well-studied Milky Way (MW) RR Lyrae with spectroscopic metallicities and Gaia eDR3 parallaxes. Gai…
The First Short GRB Millimeter Afterglow: The Wide-angled Jet of the Extremely Energetic SGRB 211106A
Kilpatrick, Charles D.; Bhandari, Shivani; Fong, Wen-fai +14 more
We present the discovery of the first millimeter afterglow of a short-duration γ-ray burst (SGRB) and the first confirmed afterglow of an SGRB localized by the GUANO system on Swift. Our Atacama Large Millimeter/Sub-millimeter Array (ALMA) detection of SGRB 211106A establishes an origin in a faint host galaxy detected in Hubble Space Telescope ima…
Snails across Scales: Local and Global Phase-mixing Structures as Probes of the Past and Future Milky Way
Hogg, David W.; Laporte, Chervin F. P.; Price-Whelan, Adrian M. +3 more
Signatures of vertical disequilibrium have been observed across the Milky Way's (MW's) disk. These signatures manifest locally as unmixed phase spirals in z-v z space ("snails-in-phase"), and globally as nonzero mean z and v z , wrapping around the disk into physical spirals in the x-y plane ("snails-in-space"). We explore…
GaiaHub: A Method for Combining Data from the Gaia and Hubble Space Telescopes to Derive Improved Proper Motions for Faint Stars
Anderson, Jay; van der Marel, Roeland P.; Watkins, Laura L. +6 more
We present GAIAHUB, a publicly available tool that combines Gaia measurements with Hubble Space Telescope (HST) archival images to derive proper motions (PMs). It increases the scientific impact of both observatories beyond their individual capabilities. Gaia provides PMs across the whole sky, but the limited mirror size and time baseline restrict…
Methanol Mapping in Cold Cores: Testing Model Predictions
Vasyunin, Anton; Caselli, Paola; Punanova, Anna +5 more
Chemical models predict that in cold cores gas-phase methanol is expected to be abundant at the outer edge of the CO depletion zone, where CO is actively adsorbed. CO adsorption correlates with volume density in cold cores, and, in nearby molecular clouds, catastrophic CO freeze-out happens at volume densities above 104 cm-3.…
Early-time Ultraviolet Spectroscopy and Optical Follow-up Observations of the Type IIP Supernova 2021yja
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Modjaz, Maryam +19 more
We present three epochs of early-time ultraviolet (UV) and optical HST/STIS spectroscopy of the young, nearby Type IIP supernova (SN) 2021yja. We complement the HST data with two earlier epochs of Swift UVOT spectroscopy. The HST and Swift UVOT spectra are consistent with those of other well-studied Type IIP SNe. The UV spectra exhibit rapid cooli…
First Observation of the MeV Gamma-Ray Universe with Bijective Imaging Spectroscopy Using the Electron-tracking Compton Telescope on Board SMILE-2+
Hamaguchi, Kenji; Takada, Atsushi; Kubo, Hidetoshi +12 more
MeV gamma-rays provide a unique window for the direct measurement of line emissions from radioisotopes, but observations have made little significant progress since COMPTEL on board the Compton Gamma-ray Observatory (CGRO). To observe celestial objects in this band, we are developing an electron-tracking Compton camera (ETCC) that realizes both bi…
A 2D Model for Coronal Bright Points: Association with Spicules, UV Bursts, Surges, and EUV Coronal Jets
Moreno-Insertis, F.; Nóbrega-Siverio, D.
Coronal bright points (CBPs) are ubiquitous structures in the solar atmosphere composed of hot small-scale loops observed in extreme-ultraviolet (EUV) or X-rays in the quiet Sun and coronal holes. They are key elements to understanding the heating of the corona; nonetheless, basic questions regarding their heating mechanisms, the chromosphere unde…