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The character of the warm ionized medium
Geyer, Marisa; Walker, Mark A.
Herschel observations of far-infrared N+ emission lines have demonstrated that dense plasma, with n_ e∼ 30 cm^{-3}, is ubiquitous in the inner Galactic plane. By combining the information from Herschel with other tracers of ionized gas, we build a picture of this dense plasma. We adopt a collisional ionization model, so the analysis is …
Ejecta deposits of Bakhuysen Crater, Mars
Tornabene, L. L.; Osinski, G. R.; Caudill, C. M.
Bakhuysen Crater is a Late Noachian to Early Hesperian age ∼150 km-diameter impact structure located in the heavily cratered southern highlands of Mars. It is one of the largest craters on Mars with well-preserved ejecta deposits. Impact ejecta deposits allow an understanding of crustal composition, volatile content, and evolution of terrestrial p…
Manifestations of bright points observed in G-band and Ca II H by Hinode/SOT
Lin, Jun; Wu, Ning; Liu, Yan-Xiao
An algorithm was developed for identifying and tracking a magnetic bright point, or bright point (BP) for short, observed in both the photosphere (G-band) and chromosphere (Ca II H), as well as for pairing a photospheric BP (PBP) with its conjugate chromospheric BP (CBP). Two sets of data observed by Hinode/SOT in the quiet Sun near the disk cente…
Analysis of the X-ray emission of OB stars: O stars
Ryspaeva, Elizaveta; Kholtygin, Alexander
We investigate the global properties of X-ray emission from O stars, analyzing the X-ray spectra of 32 O stars from archival data of the XMM-Newton space observatory. We examine two hypotheses about of the origin of X-ray emission from O stars. The first is a paradigm proposed by Pollock, that was revealed from an analysis of the ζ Ori X-ray obser…
A magnetic study of the δ Scuti variable HD 21190 and the close solar-type background star CPD -83°64B
Ilyin, I.; Niemczura, E.; Hubrig, S. +3 more
HD 21190 is a known δ Scuti star showing Ap star characteristics and a variability period of 3.6 h discovered by the Hipparcos mission. Using Gaia DR1 data for an astrometric analysis, it was recently suggested that HD 21190 forms a physical binary system with the companion CPD -83° 64B. An atmospheric chemical analysis based on High Accuracy Radi…
Magnetically Controlled Density Structures in the Martian Ionosphere: Are they Stably Recurring?
Venkateswara Rao, N.; Mohanamanasa, P.; Rao, S. V. B. +1 more
MARSIS instrument aboard the Mars Express spacecraft regularly detects the magnetically controlled density structures (MCDSs) in the Martian ionosphere. In this paper, we studied the recurrence characteristics of these MCDSs using long-term (more than a decade) MARSIS observations over a selected region of 35° to 40° longitude and -10° to 10° lati…
Ultraluminous X-ray sources: new distance indicators?
Różańska, A.; Madej, J.; Bresler, K. +2 more
Aims: In this paper we fit the NuSTAR and XMM-Newton data of three sources: NGC 7793 P13, NGC5907 ULX1, and Circinus ULX5.
Methods: Our single model contains emission from a non-spherical system: a neutron star plus an accretion disk directed towards the observer.
Results: We obtained a very good fit with the reduced χ2 p…
Astrometric test of the weak equivalence principle
Xie, Yi
Weak equivalence principle (WEP) is, for the first time, tested by astrometry on quasars in the sky measured in two wavelengths. Compared to previous WEP tests based on the Shapiro time delay of massless particles, this one has profound superiority that nearly 1 700 quasars with best measured positions commonly in the optical and radio bands are a…
The role of external far-ultraviolet irradiation in the survival of astrophysical ices in Elias 29
Rocha, W. R. M.; Pilling, S.
The survival of astrophysical ices in star-forming regions depends on the suitability of temperature, density and radiation conditions. In this article, the role of the interstellar radiation field (ISRF) on ices in Elias 29 is addressed. This object is the most luminous protostar in the ρ Oph E molecular cloud and is surrounded by many young stel…
Multiconfiguration Dirac-Hartree-Fock calculations of energy levels and radiative rates of Fe VII
Li, Yang; Xu, Xiaokai; Li, Bowen +2 more
Detailed calculations are performed for 134 fine-structure levels of the 3p63d2, 3p63d4s, 3p53d3 and 3p63d4p configurations in Fe VII using the multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction (RCI) methods. Important electron correlation effe…