Search Publications
Inference of Solar Rotation from Perturbations of Acoustic Mode Eigenfunctions
Roth, Markus; Schad, Ariane
Today's picture of the internal solar rotation rate profile results essentially from helioseismic analyses of frequency splittings of resonant acoustic waves. Here we present another, complementary estimation of the internal solar rotation rate using the perturbation of the shape of the acoustic waves. For this purpose, we extend a global heliosei…
Toward Solving the Puzzle: Dissecting the Complex Merger A521 with Multiwavelength Data
Kim, Jae-Woo; Jee, M. James; Finner, Kyle +3 more
A521 has been a subject of extensive panchromatic studies from X-ray to radio. The cluster possesses a number of remarkable features, including a bright radio relic with a steep spectrum, more than three distinct galaxy groups forming a filament, and two disturbed X-ray peaks at odds with the distant position and tilted orientation of the radio re…
Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids: Final Results
Schaefer, Gail H.; Bond, Howard E.; Evans, Nancy Remage +13 more
Cepheids in multiple systems provide information on the outcome of the formation of massive stars. They can also lead to exotic end-stage objects. This study concludes our survey of 70 galactic Cepheids using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) with images at two wavelengths to identify companions closer than 5″. In the ent…
Persistent Emission Properties of SGR J1935+2154 during Its 2020 Active Episode
Göğüş, Ersin; Kouveliotou, Chryssa; Lin, Lin +6 more
We present detailed spectral and temporal characteristics of the persistent X-ray emission of SGR J1935+2154 based on our XMM-Newton and Chandra observations taken in the aftermath of its 2020 April burst storm, during which hundreds of energetic X-ray bursts were emitted, including one associated with an extraordinary fast radio burst. We clearly…
Herschel/PACS OH Spectroscopy of Seyfert, LINER, and Starburst Galaxies
Spinoglio, Luigi; Fernández-Ontiveros, Juan Antonio; Malkan, Matthew A. +2 more
We investigated the 65, 71, 79, 84, 119, and 163 µm OH doublets of 178 local (0 < z < 0.35) galaxies. They were observed using the Herschel/Photoconductor Array Camera and Spectrometer, including Seyfert galaxies, low-ionization nuclear emission-line regions, and star-forming galaxies. We observe these doublets exclusively in absorptio…
The MESAS Project: ALMA Observations of the F-type Stars γ Lep, γ Vir A, and γ Vir B
De la Luz, V.; Moór, A.; White, Jacob Aaron +7 more
The spectrum of stars in the submillimeter to centimeter wavelength range remains poorly constrained due to a lack of data for most spectral types. An accurate characterization of stellar emission in this regime is needed to test stellar atmosphere models, and is also essential for revealing emission associated with unresolved circumstellar debris…
Prediction and Understanding of Soft-proton Contamination in XMM-Newton: A Machine Learning Approach
Tiengo, Andrea; Allen, Robert C.; Kuntz, K. D. +10 more
One of the major and unfortunately unforeseen sources of background for the current generation of X-ray telescopes are few tens to hundreds of keV (soft) protons concentrated by the mirrors. One such telescope is the European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton). Its observing time lost due to background contamination is ab…
Crepuscular Rays from the Highly Inclined Active Galactic Nucleus in IC 5063
Ho, Luis C.; Elvis, Martin; Barth, Aaron J. +10 more
On Earth near sunset, the Sun may cast "crepuscular rays" such that clouds near the horizon obscure the origin of light scattered in bright rays. In principle, active galactic nuclei (AGN) should be able to produce similar effects. Using new Hubble Space Telescope (HST) near-infrared and optical observations, we show that the active galaxy IC 5063…
Existence of the Metal-rich Stellar Halo and High-velocity Thick Disk in the Galaxy
Shi, Jianrong; Ma, Jun; Du, Cuihua +3 more
Based on the second Gaia data release (DR2), combined with the LAMOST and APOGEE spectroscopic surveys, we study the kinematics and metallicity distribution of the high-velocity stars that have a relative speed of at least 220 $\mathrm{km}\ {{\rm{s}}}^{-1}$ with respect to the local standard of rest in the Galaxy. The rotational velocity distribut…
Spectral Structures of Type II Solar Radio Bursts and Solar Energetic Particles
Yashiro, Seiji; Nitta, Nariaki V.; Iwai, Kazumasa +1 more
We investigated the relationship between the spectral structures of type II solar radio bursts in the hectometric and kilometric wavelength ranges and solar energetic particles (SEPs). To examine the statistical relationship between type II bursts and SEPs, we selected 26 coronal mass ejection (CME) events with similar characteristics (e.g., initi…