Search Publications
An Unidentified Fermi Source Emitting Radio Bursts in the Galactic Bulge
Schinzel, F. K.; Bower, Geoffrey C.; Demorest, Paul B. +5 more
We report on the detection of radio bursts from the Galactic bulge using the real-time transient detection and localization system, realfast. The pulses were detected commensally on the Karl G. Jansky Very Large Array during a survey of unidentified Fermi γ-ray sources. The bursts were localized to subarcsecond precision using realfast fast-sample…
Constraints on Acoustic Wave Energy Fluxes and Radiative Losses in the Solar Chromosphere from Non-LTE Inversions
Milić, I.; da Silva Santos, J. M.; de la Cruz Rodríguez, J. +3 more
Accurately assessing the balance between acoustic wave energy fluxes and radiative losses is critical for understanding how the solar chromosphere is thermally regulated. We investigate the energy balance in the chromosphere by comparing deposited acoustic flux and radiative losses under quiet and active solar conditions using non–local thermodyna…
Stellar Pulsation and Evolution: A Combined Theoretical Renewal and Updated Models (SPECTRUM). I. Updating Radiative Opacities for Pulsation Models of Classical Cepheid and RR-Lyrae
Marconi, Marcella; Molinaro, Roberto; De Somma, Giulia +1 more
Pulsating stars are universally recognized as precise distance indicators and tracers of stellar populations. Their variability, combined with well-defined relationships between pulsation properties and intrinsic evolutionary parameters such as luminosity, mass, and age, makes them essential for understanding galactic evolution and retrieving star…
Testing He II Emission from Wolf–Rayet Stars as a Dust Attenuation Measure in Eight Nearby Star-forming Galaxies
Leitherer, Claus; Lee, Janice C.; Maschmann, Daniel +2 more
The ability to determine galaxy properties such as masses, ages, and star formation rates robustly is critically limited by the ability to measure dust attenuation accurately. Dust reddening is often characterized by comparing observations to models of either nebular recombination lines or the UV continuum. Here, we use a new technique to measure …
Mapping the Longitudinal Magnetic Field in the Atmosphere of an Active Region Plage from the Inversion of the Near-ultraviolet CLASP2.1 Spectropolarimetric Data
Song, Donguk; Rachmeler, Laurel A.; Kobayashi, Ken +10 more
We apply the HanleRT Tenerife Inversion Code to the spectropolarimetric observations obtained by the Chromospheric Layer Spectropolarimeter. This suborbital space experiment measured the variation with wavelength of the four Stokes parameters in the near-ultraviolet spectral region of the Mg II h and k lines over a solar disk area containing part …
Inversion for Inferring Solar Meridional Circulation: The Case with Constraints on Angular Momentum Transport inside the Sun
Sekii, Takashi; Hotta, Hideyuki; Hatta, Yoshiki
We have carried out inversions of travel times as measured by Gizon et al. to infer the internal profile of the solar meridional circulation (MC). A linear inverse problem has been solved by the regularized least-squares method with a constraint that the angular momentum (AM) transport by MC should be equatorward (HK21-type constraint). Our motiva…
The AH Pictoris Syndrome: Continuous Trains of Stunted Outbursts in Novalike Variables
Bruch, Albert
Novalike variables are a subgroup of cataclysmic variables (CVs) that—unlike dwarf novae—do not exhibit strong brightenings in their long-term light curves. Variations over timescales of weeks, months, or years are mostly restricted to irregular low-amplitude modulations. However, some of them occasionally suffer from so-called stunted outbursts, …
Molecular Gas Tracers in Young and Old Protoplanetary Disks
Zhang, Ke; Cleeves, L. Ilsedore; Bergin, Edwin A. +6 more
Molecular emission is used to investigate both the physical and chemical properties of protoplanetary disks. Therefore, to derive disk properties accurately, we need a thorough understanding of the behavior of the molecular probes upon which we rely. Here we investigate how the molecular line emission of N2H+, HCO+…
Detection of the Actinide Th in an r-process-enhanced Star with Accretion Origin
Zhao, Gang; Li, Haining; Matsuno, Tadafumi +4 more
The thorium and six second-peak r-process element (56 ≤ Z ≤ 72) abundances are determined for the α-poor star LAMOST J1124+4535 based on a high-resolution spectrum obtained with the High Dispersion Spectrograph on the Subaru Telescope. The age of J1124+4535 is 11.3 ± 4.4 Gyr using thorium and other r-process element abundances. J1124+4535 is confi…
Circumgalactic Environments Around Distant Quasars 3C 9 and 4C 05.84
Kriek, Mariska; Armus, Lee; Wright, Shelley A. +6 more
We present results from the Quasar hosts Unveiled by high Angular Resolution Techniques survey studying the circumgalactic medium (CGM) by observing rest-frame UV emission lines Lyα, C IV, and He II around two radio-loud quasars, 3C 9 (z = 2.02) and 4C 05.84 (z = 2.32), using the Keck Cosmic Web Imager. We detect large-scale Lyα nebulae around bot…