Search Publications
Solar Eruptive Phenomena Associated with Solar Energetic Electron Spectral Types
Krucker, Säm; Wimmer-Schweingruber, Robert F.; Wang, Linghua +3 more
The energy spectral shape of solar energetic electron events carries important information on the energetic electron source/acceleration at the Sun. We investigate the association of six newly identified solar energetic electron spectral types with solar eruptive phenomena, including the downward double-power-law (DDPL) spectrum with break energy …
Host Galaxy and Nuclear Properties of IR-selected AGNs with and without Outflow Signatures
Li, Zi-Jian; Dai, Y. Sophia; Oio, Gabriel A. +1 more
Active galactic nucleus (AGN) driven outflows can have a significant impact on the evolution of the host galaxy. In this work, we compare the properties of galaxies that host AGNs with and without outflows. Our sample consists of 103 AGNs identified by mid-IR color–color selection and confirmed with optical spectroscopy at a redshift range of 0.3 …
First Direct Imaging of a Kelvin–Helmholtz Instability by PSP/WISPR
Vourlidas, Angelos; Stenborg, Guillermo; Howard, Russell A. +3 more
We present a comprehensive analysis aimed at proving the hypothesis that a train of small-scale features observed by the Wide-field Imager (WISPR) onboard the Parker Solar Probe (PSP) are the signature of a Kelvin–Helmholtz instability (KHI). These features were seen near the flank of a Coronal Mass Ejection (CME) wake between 7.5 R ⊙ a…
A Data-driven Spectral Model of Main-sequence Stars in Gaia DR3
Bedell, Megan; Angelo, Isabel; Ness, Melissa +1 more
Precise spectroscopic classification of planet hosts is an important tool of exoplanet research at both the population and individual system level. In the era of large-scale surveys, data-driven methods offer an efficient approach to spectroscopic classification that leverages the fact that a subset of stars in any given survey has stellar propert…
Obliquity Constraints for the Extremely Eccentric Sub-Saturn Kepler-1656 b
Huber, Daniel; Howard, Andrew W.; Petigura, Erik A. +25 more
The orbits of close-in exoplanets provide clues to their formation and evolutionary history. Many close-in exoplanets likely formed far out in their protoplanetary disks and migrated to their current orbits, perhaps via high-eccentricity migration (HEM), a process that can also excite obliquities. A handful of known exoplanets are perhaps caught i…
Probing the Stellar Populations and Star Formation History of Early-type Galaxies at 0 < z < 1.1 in the Rest-frame Ultraviolet
Desprez, Guillaume; Sawicki, Marcin; Gwyn, Stephen +6 more
We measure the evolution of the rest-frame near-ultraviolet (NUV)‑V colors for early-type galaxies in clusters at 0 < z < 1.1 using data from the Hyper Suprime-Cam Subaru Strategic Program, CFHT Large Area U-band Deep Survey, and local Sloan Digital Sky Survey clusters observed with Galaxy Evolution Explorer. Our results show that there is a…
TESS Asteroseismology of β Hydri: A Subgiant with a Born-again Dynamo
Stassun, Keivan G.; Metcalfe, Travis S.; van Saders, Jennifer L. +12 more
The solar-type subgiant β Hyi has long been studied as an old analog of the Sun. Although the rotation period has never been measured directly, it was estimated to be near 27 days. As a Southern Hemisphere target, it was not monitored by long-term stellar activity surveys, but archival International Ultraviolet Explorer data revealed a 12 yr activ…
The MUSE Ultra Deep Field (MUDF). VI. The Relationship between Galaxy Properties and Metals in the Circumgalactic Medium
Rafelski, Marc; Beckett, Alexander; Fumagalli, Michele +10 more
We present initial results associating galaxies in the Multi-Unit Spectroscopic Explorer (MUSE) Ultra Deep Field (MUDF) with gas seen in absorption along the line of sight to two bright quasars in this field to explore the dependence of metals in the circumgalactic medium (CGM) on galaxy properties. The MUDF includes ∼140 hr of Very Large Telescop…
Modeling of the Polytropic Index and Temperature Anisotropy in the Solar Wind
Engelbrecht, N. E.; Strauss, R. D.; Desta, Ephrem Tesfaye
The polytropic index is a fundamental physical parameter related to the thermodynamic processes present in space and astrophysical plasmas. This paper investigates the theoretical relationship between the polytropic index and the temperature anisotropy for flow parameters relevant to space plasmas. The derivation is based on the Chew–Goldberger–Lo…
Magnetic Fields in Giant Filaments Probed by the Velocity Gradient Technique: Regular Magnetic Field Interrupted by Magnetization Gaps
Li, Dalei; Tang, Xindi; Zhou, Jianjun +7 more
We study the magnetic field structures in six giant filaments associated with the spiral arms of the Milky Way by applying the velocity gradient technique (VGT) to the 13CO spectroscopic data from the GRS, FUGIN, and SEDIGSM surveys. Unlike dust-polarized emission, the VGT allows us to separate the foreground and background using the ve…