Search Publications
Hubble Space Telescope Observations of GW170817: Complete Light Curves and the Properties of the Galaxy Merger of NGC 4993
Kilpatrick, Charles D.; Leja, Joel; Fong, Wen-fai +10 more
We present the complete set of Hubble Space Telescope imaging of the binary neutron star merger GW170817 and its optical counterpart AT 2017gfo. Including deep template imaging in F814W, F110W, F140W, and F160W at 3.4 yr post-merger, we reanalyze the full light curve of AT 2017gfo across 12 bands from 5 to 1273 rest-frame days after merger. We obt…
Properties of Host Galaxies of Submillimeter Sources as Revealed by JWST Early Release Observations in SMACS J0723.3-7327
Yan, Haojing; Cheng, Cheng; Willmer, Christopher N. A. +3 more
Using the 0.9-4.4 µm imaging data from the James Webb Space Telescope (JWST) early release observation in the SMACS J0723.3-7327 galaxy cluster field, we discuss the properties of three submillimeter galaxies (SMGs) detected by the Atacama Large Millimeter/submillimeter Array Array. These sources are magnified by 1.4-2.1 × due to gravitation…
Patches of Magnetic Switchbacks and Their Origins
de Wit, Thierry Dudok; Velli, Marco; Bale, Stuart D. +18 more
Parker Solar Probe (PSP) has shown that the solar wind in the inner heliosphere is characterized by the quasi omnipresence of magnetic switchbacks ("switchback" hereinafter), local backward bends of magnetic field lines. Switchbacks also tend to come in patches, with a large-scale modulation that appears to have a spatial scale size comparable to …
A Maximum Likelihood Calibration of the Tip of the Red Giant Branch Luminosity from High Latitude Field Giants Using Gaia Early Data Release 3 Parallaxes
Casertano, Stefano; Li, Siyang; Riess, Adam G.
The calibration of the tip of the red giant branch (TRGB) in the I band has a direct role in determinations of the Hubble constant, a subject of recent interest due to the discrepancy between direct and indirect estimates of its value. We present a maximum likelihood method designed to obtain an independent calibration of the brightness of TRGB us…
Luminosities and Masses of Single Galactic Post-asymptotic Giant Branch Stars with Distances from Gaia EDR3: The Revelation of an s-process Diversity
Ventura, Paolo; Van Winckel, Hans; Hrivnak, Bruce J. +4 more
Post-asymptotic giant branch (AGB) stars are exquisite probes of AGB nucleosynthesis. However, the previous lack of accurate distances jeopardized comparison with theoretical AGB models. The Gaia Early Data Release 3 (Gaia EDR3) has now allowed for a breakthrough in this research landscape. In this study, we focus on a sample of single Galactic po…
Intrinsic Lyα Profiles of High-velocity G, K, and M Dwarfs
Redfield, Seth; France, Kevin; Youngblood, Allison +5 more
Observations of H I Lyman α, the brightest UV emission line of late-type stars, are critical for understanding stellar chromospheres and transition regions, modeling photochemistry in exoplanet atmospheres, and measuring the abundances of neutral hydrogen and deuterium in the interstellar medium. Yet Lyα observations are notoriously challenging ow…
Survey of Multiple Populations in Globular Clusters among Very-low-mass Stars
Milone, A. P.; Cordoni, G.; Marino, A. F. +14 more
Recent work has shown that near-infrared (NIR) Hubble Space Telescope (HST) photometry allows us to disentangle multiple populations (MPs) among M dwarfs of globular clusters (GCs) and to investigate this phenomenon in very-low-mass (VLM) stars. Here, we present the color-magnitude diagrams of nine GCs and the open cluster NGC 6791 in the F110W an…
Constraining the Nature of the 18 min Periodic Radio Transient GLEAM-X J162759.5-523504.3 via Multiwavelength Observations and Magneto-thermal Simulations
de Martino, D.; Rea, N.; Buckley, D. A. H. +14 more
We observed the periodic radio transient GLEAM-X J162759.5-523504.3 (GLEAM-X J1627) using the Chandra X-ray Observatory for about 30 ks on 2022 January 22-23, simultaneously with radio observations from the Murchison Widefield Array, MeerKAT, and the Australia Telescope Compact Array. Its radio emission and 18 min periodicity led the source to be …
The Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER). II. The Spatially Resolved Recent Star Formation History of M33
Bell, Eric F.; Williams, Benjamin F.; Choi, Yumi +11 more
We measure the spatially resolved recent star formation history (SFH) of M33 using optical images taken with the Hubble Space Telescope as part of the Panchromatic Hubble Andromeda Treasury: Triangulum Extended Region (PHATTER) survey. The area covered by the observations used in this analysis covers a de-projected area of ~38 kpc2 and …
A New Magnetic Parameter of Active Regions Distinguishing Large Eruptive and Confined Solar Flares
Hou, Yijun; Li, Ting; Yang, Shuhong +3 more
With the aim of investigating how the magnetic field in solar active regions (ARs) controls flare activity, i.e., whether a confined or eruptive flare occurs, we analyze 106 flares of Geostationary Operational Environmental Satellite class ≥M1.0 during 2010-2019. We calculate mean characteristic twist parameters α FPIL within the "flari…