Search Publications

The Link between Nonthermal Velocity and Free Magnetic Energy in Solar Flares
DOI: 10.3847/2041-8213/ad1bee Bibcode: 2024ApJ...961L..29M

Temmer, Manuela; Veronig, Astrid; Baker, Deborah +5 more

The cause of excess spectral line broadening (nonthermal velocity) is not definitively known, but given its rise before and during flaring, the causal processes hold clues to understanding the triggers for the onset of reconnection and the release of free magnetic energy from the coronal magnetic field. A comparison of data during a 9 hr period fr…

2024 The Astrophysical Journal
Hinode 2
Stripe 82X Data Release 3: Multiwavelength Catalog with New Spectroscopic Redshifts and Black Hole Masses
DOI: 10.3847/1538-4357/ad6e7d Bibcode: 2024ApJ...974..235L

Kirkpatrick, Allison; Trakhtenbrot, Benny; LaMassa, Stephanie +10 more

We present the third catalog release of the wide-area (31.3 deg2) Stripe 82 X-ray survey. This catalog combines previously published X-ray source properties with multiwavelength counterparts and photometric redshifts, presents 343 new spectroscopic redshifts, and provides black hole masses for 1297 Type 1 active galactic nuclei (AGN). W…

2024 The Astrophysical Journal
XMM-Newton 2
Ejecta–Circumstellar Medium Interaction in High-density Environment Contribution to Kilonova Emission: Application to GRB 191019A
DOI: 10.3847/1538-4357/ad2205 Bibcode: 2024ApJ...963..156W

Liang, En-Wei; Lü, Hou-Jun; Wang, Suo-Ning +4 more

The nearby long-duration GRB 191019A recently detected by Swift lacks an associated supernova and belongs to a host galaxy with little star formation activity, suggesting that the origin of this burst is the result of a merger of two compact objects with dynamical interactions in a high-density medium of an active galactic nucleus. Given the poten…

2024 The Astrophysical Journal
eHST 2
ICM-SHOX. I. Methodology Overview and Discovery of a Gas–Dark Matter Velocity Decoupling in the MACS J0018.5+1626 Merger
DOI: 10.3847/1538-4357/ad3fb5 Bibcode: 2024ApJ...968...74S

Mroczkowski, Tony; Zitrin, Adi; Stanford, S. A. +12 more

Galaxy cluster mergers are rich sources of information to test cluster astrophysics and cosmology. However, cluster mergers produce complex projected signals that are difficult to interpret physically from individual observational probes. Multi-probe constraints on the gas and dark matter (DM) cluster components are necessary to infer merger param…

2024 The Astrophysical Journal
eHST 2
Identifying New High-confidence Polluted White Dwarf Candidates Using Gaia XP Spectra and Self-organizing Maps
DOI: 10.3847/1538-4357/ad88f5 Bibcode: 2024ApJ...977...31P

Villaver, Eva; Pérez-Couto, Xabier; Pallas-Quintela, Lara +2 more

The identification of new white dwarfs (WDs) polluted with heavy elements is important since they provide a valuable tool for inferring the chemical properties of putative planetary systems accreting material on their surfaces. The Gaia space mission has provided us with an unprecedented amount of astrometric, photometric, and low-resolution (XP) …

2024 The Astrophysical Journal
Gaia 1
The X-Ray Emission Reveals the Coronal Activities of Semi-detached Binaries
DOI: 10.3847/1538-4357/ad267e Bibcode: 2024ApJ...965..167L

Liu, Junhui; Wu, Jianfeng

X-ray emission is an important tracer of stellar magnetic activity. We carried out a systematic correlation analysis for the X-ray luminosity logLX

2024 The Astrophysical Journal
Gaia XMM-Newton 1
The Evolution of Stellar X-Ray Activity and Angular Momentum as Seen by eROSITA, TESS, and Gaia
DOI: 10.3847/2041-8213/ad4c64 Bibcode: 2024ApJ...967L..36S

Stassun, Keivan G.; Kounkel, Marina

We have assembled a sample of ∼8200 stars with spectral types F5V–M5V, all having directly measured X-ray luminosities from eROSITA and rotation periods from TESS and having empirically estimated ages via their membership in stellar clusters and groups identified in Gaia astrometry (ages 3–500 Myr). This is the largest such study sample yet assemb…

2024 The Astrophysical Journal
Gaia 1
Thermal Evolution of an Active Region Through Quiet and Flaring Phases as Observed by NuSTAR, XRT, and AIA
DOI: 10.3847/1538-4357/ad37f7 Bibcode: 2024ApJ...966..197D

Reeves, Katharine K.; Grefenstette, Brian W.; Shih, Albert Y. +6 more

Solar active regions (ARs) contain a broad range of temperatures, with the thermal plasma distribution often observed to peak in the few millions of kelvin. Differential emission measure (DEM) analysis can allow instruments with diverse temperature responses to be used in concert to estimate this distribution. Nuclear Spectroscopic Telescope ARray…

2024 The Astrophysical Journal
Hinode 1
Constraining the Progenitor of the Nearby Type II-P SN 2024ggi with Environmental Analysis
DOI: 10.3847/2041-8213/ad99da Bibcode: 2024ApJ...977L..50H

Niu, Zexi; Sun, Ning-Chen; Liu, Jifeng +3 more

The progenitors of Type II-P supernovae (SN) have been confirmed to be red supergiants. However, the upper mass limit of the directly probed progenitors is much lower than that predicted by current theories, and the accurate determination of the progenitor masses is key to understand the final fate of massive stars. Located at a distance of only 6…

2024 The Astrophysical Journal
eHST 1
Active Galactic Nuclei in the Green Valley at z ∼ 0.7
DOI: 10.3847/1538-4357/ad74f1 Bibcode: 2024ApJ...974..305W

Ji, Zhiyuan; Rieke, Marcia; Williams, Christina C. +5 more

We present near-infrared (NIR) spectroscopy using the MMT and Magellan infrared spectrograph for a sample of 29 massive galaxies ( logM*/M

2024 The Astrophysical Journal
eHST 1