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The Disk Wind Contribution to the Gamma-Ray Emission from the Nearby Seyfert Galaxy GRS 1734‑292
Fukazawa, Yasushi; Inoue, Yoshiyuki; Yamada, Tomoya +4 more
Radio-quiet Seyfert galaxies have been detected in GeV gamma rays by the Fermi Large Area Telescope (LAT), but the origin of much of this emission is unclear. We consider the nearby example GRS 1734‑292, which exhibits weak starburst and jet activities that are insufficient to explain the observed gamma-ray flux. With the first detailed multiwavel…
Nonthermal Velocities in a Solar Active Region Observed by SERTS
Brosius, Jeffrey W.
We present measurements of coronal nonthermal Doppler velocities in NOAA Active Region 7870 observed by the Solar EUV Research Telescope and Spectrograph during its 1995 sounding rocket flight (SERTS-95). The instrument included a multilayer-coated toroidal diffraction grating that enhanced its sensitivity in second order at wavelengths between ab…
A Magnetohydrodynamics Simulation of Coronal Mass Ejections in the Upper Corona at 2.5R⊙ ≤ r ≤ 19R⊙
Hayashi, Keiji; Wu, Chin-Chun; Liou, Kan
The methodology of a new magnetohydrodynamics simulation model of the propagation of coronal mass ejections (CMEs) in the near-Sun solar wind region at 2.5R⊙ ≥ r ≥ 19R⊙ is presented. The simulation model first determines the steady state of the transonic/Alfvénic solar wind with the characteristic-based inner boundary treatme…
X-ray activity of nearby G-, K-, and M-type stars and implications for planet habitability around M stars
Preibisch, T.; Zhu, E.
Context. The intense X-ray and UV emission of some active M stars has raised questions about the habitability of planets around M-type stars. Aims. We aim to determine the unbiased distribution of X-ray luminosities in complete, volume-limited samples of nearby M dwarfs, and compare them to those of K and G dwarfs. Methods. We constructed volume-c…
Testing the asteroseismic estimates of stellar radii with surface brightness-colour relations and Gaia DR3 parallaxes: II. Red giants and red clump stars from the Kepler catalogue
Valle, G.; Dell'Omodarme, M.; Prada Moroni, P. G. +1 more
Context. A recent investigation highlighted peculiar trends between the radii derived from surface brightness-colour relations (SBCRs) combined with Gaia DR3 parallaxes with respect to asteroseismic scaling relation radii from K2 data. Aims.Kepler data differ from K2 data in many aspects. We investigated on the robustness of the results based on K…
Connection between steep radio spectral slopes and dust extinction in QSOs: evidence for outflow-driven shocks in dusty QSOs
Alexander, D. M.; Rosario, D. J.; Morabito, L. K. +9 more
Recent studies have found a striking positive correlation between the amount of dust obscuration and enhanced radio emission in quasi-stellar objects (QSOs). However, what causes this connection remains unclear. In this paper we analyse uGMRT Band-3 (400 MHz) and Band-4 (650 MHz) data of a sample of 38 1.0 < z < 1.5 QSOs with existing high-r…
Extending the ALMA Census of Circumstellar Disks in the Upper Scorpius OB Association
Andrews, Sean M.; Mamajek, Eric E.; Carpenter, John M. +2 more
We present Atacama Large Millimeter/submillimeter Array (ALMA) Band 7 continuum (340 GHz) and carbon monoxide (CO) J = 3–2 observations for an extended sample of disks in the Upper Scorpius OB Association (Upper Sco, age ∼10 Myr). The targets were selected from previous studies that identified new members of Upper Sco using photometry and astromet…
On the progenitor of the Crab Pulsar
Kochanek, C. S.; Cruz-Cruz, Elvira
We investigate the progenitor of the Crab supernova by examining the remnant's surrounding stellar population. The Crab is interesting because of the apparently low energy and mass of the supernova remnant. We also know it was not a binary at death and that the explosion formed a neutron star. Using Gaia EDR3 parallaxes and photometry, we analyse …
RIS: Regularized imaging spectroscopy for STIX on board Solar Orbiter
Volpara, Anna; Piana, Michele; Maria Massone, Anna +3 more
Context. The generation of spatially resolved count spectra and of cubes of count maps at different energies via imaging spectroscopy is one of the main goals of solar hard X-ray missions based on Fourier imaging. Thus, so far, for these telescopes, this goal has been realized via the generation of either count maps that are independently reconstr…
Photometric and spectroscopic studies of six W UMa-type eclipsing binaries
Li, Kai; Zhang, Bin; Wang, Jing-Jing +3 more
We performed new photometric and spectroscopic studies on six W UMa-type eclipsing binaries (V342 UMa, LX Leo, V1062 Her, V801 And, 1SWASP J165649.13+402738.4, and V1067 Her). From orbital period analysis, V342 UMa and LX Leo show continuous period decrease with a rate of -2.11(