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The Composite X-Ray Spectrum of 3CRR Quasars
Gu, Minfeng; Zhou, Minhua
The reason for the difference between the composite X-ray spectrum for radio-loud quasars (RLQs) versus radio-quiet quasars (RQQs) is still unclear. To study this difference, we built a new composite X-ray spectrum of RLQs using Chandra X-ray data and Sloan Digital Sky Survey optical data for the sample of 3CRR quasars. We find the X-ray spectra o…
Analysis of a long-duration AR throughout five solar rotations: Magnetic properties and ejective events
Ugarte-Urra, Ignacio; Mandrini, Cristina H.; Cremades, Hebe +4 more
Coronal mass ejections (CMEs), which are among the most magnificent solar eruptions, are a major driver of space weather and can thus affect diverse human technologies. Different processes have been proposed to explain the initiation and release of CMEs from solar active regions (ARs), without reaching consensus on which is the predominant scenari…
Study of the Dynamics of Convective Turbulence in the Solar Granulation by Spectral Line Broadening and Asymmetry
Katsukawa, Yukio; Ishikawa, Ryohtaroh T.; Oba, Takayoshi +3 more
In quiet regions on the solar surface, turbulent convective motions of granulation play an important role in creating small-scale magnetic structures, as well as in energy injection into the upper atmosphere. The turbulent nature of granulation can be studied using spectral line profiles, especially line broadening, which contain information on th…
Flare Properties of A-type Stars in Kepler Data
Esamdin, Ali; Bai, Jian-Ying
We analyzed the long-cadence (LC) light curves of 5435 stars with effective temperatures of 7000-10,500 K in Data Release 25 of Kepler to extend the samples of A-type flare stars and study their flare properties. A total of 103 flare stars are detected, of which 72 have the Large Sky Area Multi-Object fiber Spectroscopic Telescope spectral types, …
BC Cassiopeiae: First detection of IW Andromedae-type phenomenon among post-eruption novae
Kato, Taichi; Kojiguchi, Naoto
IW And-type dwarf novae are a recently recognized group of cataclysmic variables which are characterized by a sequence of brightening from a standstill-like phase with damping oscillations often followed by a deep dip. We found that the supposed classical nova BC Cas which erupted in 1929 experienced a state of an IW And-type dwarf nova in 2018, 8…
The INTEGRAL view of the pulsating hard X-ray sky: from accreting and transitional millisecond pulsars to rotation-powered pulsars and magnetars
Tiengo, A.; Götz, D.; Mereghetti, S. +30 more
In the last 25 years a new generation of X-ray satellites imparted a significant leap forward in our knowledge of X-ray pulsars. The discovery of accreting and transitional millisecond pulsars proved that disk accretion can spin up a neutron star to a very high rotation speed. The detection of MeV-GeV pulsed emission from a few hundreds of rotatio…
The influence of the cometary particles dynamics on the activity of comets
Wesołowski, M.
The paper deals with the dynamics of particles which are on the surface of the cometary nucleus. The key point is to research the behavior of the particles as a result of local sublimation. Generally, we can describe three mechanisms related to the particles behavior. Relatively small particles (of the order of micrometers) are ejected into the at…
The XXL Survey. XLII. Detection and characterisation of the galaxy population of distant galaxy clusters in the XXL-N/VIDEO field: A tale of variety
Chiappetti, L.; Häußler, B.; Bowler, R. A. A. +16 more
Context. Distant galaxy clusters provide an effective laboratory in which to study galaxy evolution in dense environments and at early cosmic times.
Aims: We aim to identify distant galaxy clusters as extended X-ray sources that are coincident with overdensities of characteristically bright galaxies.
Methods: We used optical and near-inf…
Herschel SPIRE Discovery of Far-infrared Excess Synchrotron Emission from the West Hot Spot of the Radio Galaxy Pictor A
Isobe, Naoki; Pearson, Chris; Tashiro, Makoto +4 more
A far-infrared counterpart to the west hot spot of the radio galaxy Pictor A is discovered with the Spectral and Photometric Imaging REceiver (SPIRE) on board Herschel. The color-corrected flux density of the source is measured as 70.0 ± 9.9 mJy at the wavelength of 350 µm. A close investigation into its radio-to-optical spectrum indicates t…
Ammonia observations towards the Aquila Rift cloud complex
Li, Dalei; Tang, Xindi; Zhou, Jianjun +7 more
We surveyed the Aquila Rift complex including the Serpens South and W 40 regions in the NH3 (1,1) and (2,2) transitions making use of the Nanshan 26-m telescope. Our observations cover an area of ~ 1.5° × 2.2° (11.4 pc × 16.7 pc). The kinetic temperatures of the dense gas in the Aquila Rift complex obtained from NH3 (2,2)/(1,…