Search Publications
Realistic Uncertainties for Fundamental Properties of Asteroseismic Red Giants and the Interplay between Mixing Length, Metallicity, and ν max
Li, Yaguang; van Saders, Jennifer; Huber, Daniel +8 more
Asteroseismic modeling is a powerful way to derive stellar properties. However, the derived quantities are limited by built-in assumptions used in stellar models. This work presents a detailed characterization of stellar model uncertainties in asteroseismic red giants, focusing on the mixing-length parameter α MLT, the initial helium fr…
A Multiwavelength Light-curve Model of the Classical Nova V339 Del: A Mechanism for the Coexistence of Dust Dip and Supersoft X-Rays
Kato, Mariko; Hachisu, Izumi; Matsumoto, Katsura
The classical nova V339 Del 2013 is characterized by a 1.5 mag dip of the V light curve owing to a dust shell formation, with which soft X-ray emissions coexist. We present a Strömgren y-band light curve, which represents continuum emission, not influenced by strong [O III] emission lines. The y light curve monotonically decreases in marked contra…
Discovering the Mass-Scaled Damping Timescale from Microquasars to Blazars
Zhang, Haoyang; Yang, Shenbang; Dai, Benzhong
Studying the variability of the accretion disks of black holes and jets is important to identify their internal physical processes. In this Letter, we obtain the characteristic damping timescale of 34 blazars and 7 microquasars from the Fermi-Large Area Telescope and the XMM-Newton X-ray telescope, respectively. We found that the mass-scaled chara…
Updated Proper Motion of the Neutron Star in the Supernova Remnant Cassiopeia A
Holland-Ashford, Tyler; Slane, Patrick; Long, Xi
In this paper, we present updated estimates of the velocity of the neutron star (NS) in the supernova remnant Cassiopeia A using over two decades of Chandra observations. We use two methods: (1) recording the NS positions from dozens of Chandra observations, including the astrometric uncertainty estimates on the data points, but not correcting the…
CEERS Key Paper. IX. Identifying Galaxy Mergers in CEERS NIRCam Images Using Random Forests and Convolutional Neural Networks
Papovich, Casey; Yang, Guang; Finkelstein, Steven L. +32 more
A crucial yet challenging task in galaxy evolution studies is the identification of distant merging galaxies, a task that suffers from a variety of issues ranging from telescope sensitivities and limitations to the inherently chaotic morphologies of young galaxies. In this paper, we use random forests and convolutional neural networks to identify …
Optical- and UV-continuum Morphologies of Compact Radio Source Hosts
Worrall, D. M.; Morganti, R.; O'Dea, C. P. +6 more
We present the first systematic search for UV signatures from radio source-driven active galactic nuclei (AGN) feedback in Compact Steep Spectrum (CSS) radio galaxies. Owing to their characteristic sub-galactic jets (1–20 kpc projected linear sizes), CSS hosts are excellent laboratories for probing galaxy scale feedback via jet-triggered star form…
The Impact of Cometary "Impacts" on the Chemistry, Climate, and Spectra of Hot Jupiter Atmospheres
Walsh, C.; Sainsbury-Martinez, F.
Impacts from icy and rocky bodies have helped shape the composition of Solar System objects; for example, the Earth–Moon system, or the recent impact of comet Shoemaker–Levy 9 with Jupiter. It is likely that such impacts also shape the composition of exoplanetary systems. Here, we investigate how cometary impacts might affect the atmospheric compo…
AGN STORM 2. X. The Origin of the Interband Continuum Delays in Mrk 817
Kaspi, Shai; Barth, Aaron J.; Horne, Keith +26 more
The local (z = 0.0315) active galactic nucleus (AGN) Mrk 817 was monitored over more than 500 days with space-borne and ground-based instruments as part of a large international campaign, AGN STORM 2. Here, we present a comprehensive analysis of the broadband continuum variations using detailed modeling of the broad line region (BLR), several type…
DIISC-III. Signatures of Stellar Disk Growth in Nearby Galaxies
Heckman, Timothy; Kennicutt, Robert C.; Thilker, David +8 more
We explore the growth of the stellar disks in 14 nearby spiral galaxies as part of the Deciphering the Interplay between the Interstellar medium, Stars, and the Circumgalactic medium (DIISC) survey. We study the radial distribution of specific star formation rates (sSFRs) and investigate the ratio of the difference in the outer and inner sSFRs (Δ<…
Contemporaneous X-Ray Observations of 30 Bright Radio Bursts from the Prolific Fast Radio Burst Source FRB 20220912A
Kaspi, Victoria M.; Bhardwaj, Mohit; Scholz, Paul +21 more
We present an extensive contemporaneous X-ray and radio campaign performed on the repeating fast radio burst (FRB) source FRB 20220912A for 8 weeks immediately following the source's detection by CHIME/FRB. This includes X-ray data from XMM-Newton, NICER, and Swift, and radio detections of FRB 20220912A from CHIME/Pulsar and Effelsberg. We detect …