Search Publications
Asteroseismic Modeling of 1153 Kepler Red Giant Branch Stars: Improved Stellar Parameters with Gravity-mode Period Spacings and Luminosity Constraints
Bi, Shaolan; Li, Yaguang; Bedding, Timothy R. +2 more
This paper reports the estimated stellar parameters of 1153 Kepler red giant branch stars determined with asteroseismic modeling. We use radial-mode oscillation frequencies, gravity-mode period spacings, Gaia luminosities, and spectroscopic data to characterize these stars. Compared with previous studies, we find that the two additional observed c…
Near-infrared Spectroscopy of Dense Ejecta Knots in the Outer Eastern Area of the Cassiopeia A Supernova Remnant
Koo, Bon-Chul; Lee, Jae-Joon; Yoon, Sung-Chul +1 more
The Cassiopeia A supernova remnant has a complex structure, manifesting the multidimensional nature of core-collapse supernova explosions. To further understand this, we carried out near-infrared multiobject spectroscopy on the ejecta knots located in the northeastern (NE) jet and Fe K plume regions, which are two distinct features in the outer ea…
A Candidate Dual QSO at Cosmic Noon
Lacy, Mark; Comerford, Julia M.; Simmons, Brooke D. +6 more
We report the discovery of a candidate dual QSO at z = 1.889, a redshift that is in the era known as "cosmic noon" where most of the universe's black hole and stellar mass growth occurred. The source was identified in Hubble Space Telescope WFC3/IR images of a dust-reddened QSO that showed two closely separated point sources at a projected distanc…
Simulated Observations of Star Formation Regions: Infrared Evolution of Globally Collapsing Clouds
Baes, Maarten; Fritz, Jacopo; Lin, Yuxin +6 more
A direct comparison between hydrodynamical simulations and observations is needed to improve the physics included in the former and to test biases in the latter. Post-processing radiative transfer and synthetic observations are now the standard way to do this. We report on the first application of the SKIRT radiative-transfer code to simulations o…
Observed UV Continuum Slopes (β) of Galaxies at z = 0.40-0.75 in the GOODS-North Field
Saha, Kanak; Windhorst, Rogier A.; Jansen, Rolf A. +1 more
We estimate the UV continuum slope (β) of 465 galaxies (with luminosities of 0.028-3.3 ${L}_{z=0.5}^{* }$ ) in the Great Observatories Origins Survey Northern field in the redshift range z = 0.40-0.75. We use two AstroSat/UVIT (N242W, N245M) bands, two Hubble Space Telescope (F275W, F336W) bands, and a KPNO (U) band to sample the UV continuum slop…
Measuring the Dust Attenuation Curves of SINGS/KINGFISH Galaxies Using Swift/UVOT Photometry
Gronwall, Caryl; Bowman, William P.; Decleir, Marjorie +3 more
We present Swift/Ultraviolet Optical Telescope (UVOT) integrated light photometry of the Spitzer Infrared Nearby Galaxies Survey (SINGS) and the Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel (KINGFISH) samples of nearby galaxies. Combining the Swift/UVOT data with archival photometry, we investigate a variety of dust attenua…
Extreme Tidal Stripping May Explain the Overmassive Black Hole in Leo I: A Proof of Concept
Loeb, Abraham; Pacucci, Fabio; Ni, Yueying
A recent study found dynamical evidence of a supermassive black hole of ~3 × 106 M ⊙ at the center of Leo I, the most distant dwarf spheroidal galaxy of the Milky Way. This black hole, comparable in mass to the Milky Way's Sgr A*, places the system >2 orders of magnitude above the standard M •-M ⋆ rel…
A Combined Radio Multi-Survey Catalog of Fermi Unassociated Sources
Schinzel, F. K.; Bruzewski, S.; Taylor, G. B.
Approximately one-third of existing γ-ray sources identified by the Fermi Gamma-Ray Space Telescope are considered to be unassociated, with no known counterpart at other frequencies/wavelengths. These sources have been the subject of intense scrutiny and observational effort during the observatory's mission lifetime, and here we present a method o…
Resolving Galactic-scale Obscuration of X-Ray AGNs at z ≳ 1 with COSMOS-Web
Koekemoer, Anton M.; Gillman, Steven; Hirschmann, Michaela +25 more
A large fraction of the accreting supermassive black hole population is shrouded by copious amounts of gas and dust, particularly in the distant (z ≳ 1) universe. While much of the obscuration is attributed to a parsec-scale torus, there is a known contribution from the larger-scale host galaxy. Using JWST/NIRCam imaging from the COSMOS-Web survey…
Energy Budget in the Solar Corona
Telloni, Daniele; Zank, Gary P.; Adhikari, Laxman +34 more
This paper addresses the first direct investigation of the energy budget in the solar corona. Exploiting joint observations of the same coronal plasma by Parker Solar Probe and the Metis coronagraph aboard Solar Orbiter and the conserved equations for mass, magnetic flux, and wave action, we estimate the values of all terms comprising the total en…