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The way to a double degenerate: ∼15-20 per cent of 1 M⊙ ≤ M ≤ 8 M⊙ stars have an M > 1 M⊙ companion
Klein, Ygal Y.; Katz, Boaz
We find that ∼15-20 per cent of A-type stars or red giants are bound with a massive companion (Msecondary > 1 M⊙) in an intermediate wide orbit (0.5 < P < 5000 yr). These massive binaries are expected to form wide-orbit, double-degenerate systems (WODDs) within ≲10 Gyr implying that ∼10 per cent of white dwarfs (WDs)…
The Panchromatic Hubble Andromeda Treasury. XVII. Examining Obscured Star Formation with Synthetic Ultraviolet Flux Maps in M31.
Bell, Eric F.; Dolphin, Andrew E.; Skillman, Evan D. +10 more
We present synthetic far- and near-ultraviolet ({FUV} and {NUV}) maps of M31, both with and without dust reddening. These maps were constructed from spatially resolved star formation histories (SFHs) derived from optical Hubble Space Telescope imaging of resolved stars, taken as part of the Panchromatic Hubble Andromeda Treasury program. We use st…
Searching for stars closely encountering with the solar system based on data from the Gaia DR1 and RAVE5 catalogues
Bobylev, V. V.; Bajkova, A. T.
We have searched for the stars that either encountered in the past or will encounter in the future with the Solar system closer than 2 pc. For this purpose, we took more than 216 000 stars with the measured proper motions and trigonometric parallaxes from the Gaia DR1 catalogue and their radial velocities from the RAVE5 catalogue. We have found se…
Spectral and time series analyses of the Seyfert 1 AGN: Zw 229.015
Rakshit, Suvendu; Adegoke, Oluwashina; Mukhopadhyay, Banibrata
We analyse the spectra of the archival XMM-Newton data of the Seyfert 1 AGN Zw 229.015 in the energy range 0.3-10.0 keV. When fitted with a simple power law, the spectrum shows signatures of weak soft excess below 1.0 keV. We find that both thermal Comptonization and relativistically blurred reflection models provide the most acceptable spectral f…
Comparison of the coronal mass ejection shock acceleration of three widespread SEP events during solar cycle 24
St. Cyr, O. C.; Gopalswamy, N.; Mäkelä, P. +1 more
We studied three solar energetic particle (SEP) events observed on 14 August 2010, 3 November 2011, and 5 March 2013 by Solar Terrestrial Relations Observatory (STEREO) A, B, and near-Earth (L1) spacecraft with a longitudinal distribution of particles >90°. Using a forward modeling method combined with extreme ultraviolet and white-light images…
Understanding the Links among the Magnetic Fields, Filament, Bipolar Bubble, and Star Formation in RCW 57A Using NIR Polarimetry
Tamura, M.; Nishiyama, S.; Wang, Jia-Wei +10 more
The influence of magnetic fields (B-fields) on the formation and evolution of bipolar bubbles, due to the expanding ionization fronts (I-fronts) driven by the H II regions that are formed and embedded in filamentary molecular clouds, has not been well-studied yet. In addition to the anisotropic expansion of I-fronts into a filament, B-fields are e…
The Solar Neighborhood. XLII. Parallax Results from the CTIOPI 0.9 m Program—Identifying New Nearby Subdwarfs Using Tangential Velocities and Locations on the H-R Diagram
Henry, Todd J.; Winters, Jennifer G.; Jao, Wei-Chun +4 more
Parallaxes, proper motions, and optical photometry are presented for 51 systems consisting of 37 cool subdwarf and 14 additional high proper motion systems. Thirty-seven systems have parallaxes reported for the first time, 15 of which have proper motions of at least 1″ yr-1. The sample includes 22 newly identified cool subdwarfs within …
Finite-frequency Sensitivity Kernels in Spherical Geometry for Time-Distance Helioseismology
Mandal, Krishnendu; Hanasoge, Shravan M.; Bhattacharya, Jishnu +1 more
The inference of internal properties of the Sun from surface measurements of wave travel times is the goal of time-distance helioseismology. A critical step toward the accurate interpretation of shifts in travel time is the computation of sensitivity functions linking seismic measurements to internal structure. Here we calculate finite-frequency s…
A deep search for the release of volcanic gases on Mars using ground-based high-resolution infrared and submillimeter spectroscopy: Sensitive upper limits for OCS and SO2
Villanueva, G. L.; Mumma, M. J.; Tokunaga, A. T. +1 more
Recent volcanic activity has long been considered a distinct possibility that would place major constraints on the evolution of Mars' interior. Volcanic activity would result in the outgassing of sulfur-bearing species. As part of our multi-band search for active release of volcanic gases on Mars, we looked for carbonyl sulfide (OCS) at its combin…
Recombining Plasma and Gamma-Ray Emission in the Mixed-morphology Supernova Remnant 3C 400.2
Fukui, Y.; Sano, H.; Sezer, A. +2 more
3C 400.2 belongs to the mixed-morphology supernova remnant class, showing center-filled X-ray and shell-like radio morphology. We present a study of 3C 400.2 with archival Suzaku and Fermi-LAT observations. We find recombining plasma (RP) in the Suzaku spectra of north-east and south-east regions. The spectra of these regions are well described by…