Search Publications
Sloan Digital Sky Survey IV MaStar: Quantification and Abatement of Interstellar Absorption in the Largest Empirical Stellar Spectral Library
Law, David R.; Howk, J. Christopher; Thomas, Daniel +6 more
We assess the impact of Ca II λ λ3934, 3969 and Na I λ λ5891, 5897 absorption arising in the interstellar medium (ISM) on the Sloan Digital Sky Survey-IV MaNGA Stellar Library (MaStar) and produce corrected spectroscopy for 80% of the 24,162-star catalog. We model the absorption strength of these transitions as a function of the stellar distance, …
Introducing the Condor Array Telescope. V. Deep Broad- and Narrowband Imaging Observations of the M81 Group
Walter, Frederick M.; Shara, Michael M.; Lanzetta, Kenneth M. +3 more
We used the Condor Array Telescope to obtain deep imaging observations through the luminance broadband and He II 468.6 nm, [O III] 500.7 nm, He I 587.5 nm, Hα, [N II] 658.4 nm, and [S II] 671.6 nm narrowband filters of an extended region comprising 13 "Condor fields" spanning ≈ 8 × 8 deg2 on the sky centered near M81 and M82. Here we de…
New insights into the proton precipitation sites in solar flares
Krucker, Säm; Battaglia, Andrea Francesco
Aims. We revisit the Reuven Ramaty High Energy Solar Spectrocopy Imager (RHESSI) γ-ray observations of the extraordinary GOES X25 flare SOL2003-10-28T11:10 to investigate previously reported conclusions that flare-accelerated electrons and protons precipitate along spatially separated flare loops. Methods. In contrast to previous works that recons…
Similarities and Differences between ICME-driven Shocks Observed by VEX (∼0.72 au) and WIND (∼1.0 au)
Xu, Qi; Feng, Xueshang; Shen, Zhenning +7 more
The features of interplanetary shocks driven by interplanetary coronal mass ejections (ICMEs) observed by WIND (∼1.0 au) and Venus Express (VEX; ∼0.72 au) during the same period are statistically analyzed by comparing their similarities and differences. It is found that the proportion of ICME-driven shocks in all shocks decreases slightly from ∼0.…
Machine learning-based identification of Gaia astrometric exoplanet orbits
Sahlmann, Johannes; Gómez, Pablo
The third Gaia data release (DR3) contains ~170 000 astrometric orbit solutions of two-body systems located within ~500 pc of the Sun. Determining component masses in these systems, in particular of stars hosting exoplanets, usually hinges on incorporating complementary observations in addition to the astrometry, e.g. spectroscopy and radial veloc…
Longitudinal Dependence of Heavy Ion Composition in the 2021 October 28 Ground Level Enhancement Event
Mitchell, D. G.; McComas, D. J.; Mitchell, J. G. +19 more
The 2021 October 28 solar energetic particle (SEP) event was a rare ground level enhancement (GLE) event, where secondary particles from the interactions of SEPs with the Earth's atmosphere were detected by neutron monitors on the ground. A number of papers have examined the solar signatures, neutron monitor observations, and the characteristics o…
Compact [O III] Emission-line Regions ("Green Seeds") in Hα Emitters at Cosmic Noon from JWST Observations
Malkan, Matthew A.; Spitler, Lee; Motohara, Kentaro +1 more
We present a rest-frame optical, spatially resolved analysis of more than 100 Hα emitters (HAEs) at z ∼ 2.2 in the ZFOURGE-CDFS field using NIRCam imaging from the JWST Advanced Deep Extragalactic Survey. The ultradeep, high-resolution data give us maps of the resolved emission-line regions of HAEs with stellar mass ranging from 108 M
X-ray polarimetric features of gamma-ray bursts across varied redshifts and hints for axionlike particles
Wang, Zhongxiang; Fang, Taotao; Huang, Feng +1 more
Polarimetric features during the prompt phase of gamma-ray bursts (GRBs) have been essential for elucidating the debated emission mechanisms and gaining insight into the inner structure of GRBs. However, the potential impact of photon-axionlike particle (ALP) mixing in extragalactic magnetic fields, leading to significant modifications to the init…
The Radiowave Hunt for Young Stellar Object Emission and Demographics (RADIOHEAD): A Radio Luminosity–Spectral Type Dependence in Taurus–Auriga YSOs
Wilner, David J.; Koch, Eric W.; Andrews, Sean M. +4 more
We measure the radio continuum fluxes at the locations of all Gaia-confirmed members of Taurus–Auriga using Karl G. Jansky Very Large Array Sky Survey data (VLASS; 2–4 GHz, σVLASS ~ 110–140 µJy, 2
The temporal and spatial variations of lithium abundance in the Galactic disc
Shi, Jianrong; Chen, Yuqin; Bi, Shaolan +6 more
This study investigates the temporal and spatial variations in lithium abundance within the Milky Way using a sample of 22 034 main-sequence turn-off (MSTO) stars and subgiants, characterized by precise stellar ages, 3D non-local thermodynamic equilibrium lithium abundances, and birth radii. Our results reveal a complex variation in lithium abunda…