Search Publications
Science with the AstroSat Soft X-ray telescope: An overview
Dewangan, Gulab C.; Singh, Kulinder Pal; Bhattacharyya, Sudip +6 more
The Soft X-ray Telescope (SXT) aboard the AstroSat satellite is the first Indian X-ray telescope in space. It is a modest size X-ray telescope with a charge coupled device (CCD) camera in the focal plane, which provides X-ray images in the
Kinematics and ellipsoidal motion of the mid to late M-type stars
Elsanhoury, Waleed H.; Al-Johani, Amnah S.; Nouh, Mohamed I. +1 more
Truly, kinematics in the Solar neighborhood has provided important information both for the structure and for the evolution of the Galaxy since the early 20th century. The relationship between Oort constants and the ratio of the velocity dispersion are important quantities in stellar kinematics. In the present paper, we calculated the kinematical …
Analysis of Hybrid Gas-Dust Outbursts Observed at 67P/Churyumov-Gerasimenko
Parker, Joel Wm.; Bertaux, Jean-Loup; Stern, S. Alan +14 more
Cometary outbursts offer a valuable window into the composition of comet nuclei with their forceful ejection of dust and volatiles in explosive events, revealing the interior components of the comet. Understanding how different types of outbursts influence the dust properties and volatile abundances, to better interpret what signatures can be attr…
Updated studies on exomoons in the HD 23079 system
Cuntz, M.; Jagtap, O.; Quarles, B.
We re-evaluate the outer edge of orbital stability for possible exomoons orbiting the radial velocity planet discovered in the HD 23079 system. In this system, a solar-type star hosts a Jupiter-mass planet in a nearly circular orbit in the outer stellar habitable zone. The outer stability limit of exomoons is deduced using N-body and tidal migrati…
Solar Orbiter observations of the structure of reconnection outflow layers in the solar wind
Lewis, G. R.; Fedorov, A.; Livi, S. +22 more
We briefly review an existing model of the structure of reconnection layers which predicts that several more distinct layers, in the form of contact discontinuities, rotational Alfvèn waves, or slow shocks, should be identifiable in solar wind reconnection events than are typically reported in studies of reconnection outflows associated with bifur…
Magnetic Reconnection Inside Solar Wind Rotational Discontinuity During Its Interaction With the Quasi-Perpendicular Bow Shock and Magnetosheath
Wang, Xueyi; Lin, Yu; Du, Aimin +1 more
Using a three-dimensional global hybrid simulation, we investigate the formation and evolution of ion-scale magnetic reconnection inside an interplanetary rotational discontinuity (RD) owing to its interaction with the quasi-perpendicular (Q-⊥) bow shock and the magnetosphere. The interplanetary magnetic field (IMF) is initially predominantly nort…
Non-thermal Electron Energization During the Impulsive Phase of an X9.3 Flare Revealed by Insight-HXMT
Wang, W.; Tian, H.; Zhang, S. +8 more
The X9.3 flare SOL20170906T11:55 was observed by the CsI detector aboard the first Chinese X-ray observatory Hard X-ray Modulation telescope (Insight-HXMT). Using the wavelets method, we report 22 s quasiperiodic pulsations during the impulsive phase. The spectra from 100 keV to 800 keV show the evolution with the gamma-ray flux of a power-law pho…
Hard X-Ray Emission Associated with White Dwarfs. IV. Signs of Accretion from Substellar Companions
Toalá, Jesús A.; Guerrero, Martín A.; Chu, You-Hua +3 more
With an effective temperature of ≃200,000 K, KPD 0005+5106 is one of the hottest white dwarfs (WDs). ROSAT unexpectedly detected "hard" (∼1 keV) X-rays from this apparently single WD. We have obtained Chandra observations that confirm the spatial coincidence of this hard X-ray source with KPD 0005+5106. We have also obtained XMM-Newton observation…
Purveyors of fine halos. III. Chemical abundance analysis of a potential ωCen associate
Hanke, Michael; Hansen, Camilla Juul; Bonifacio, Piercarlo +3 more
Globular clusters (GCs) are important donors to the build-up of the Milky Way (MW) stellar halo, having contributed at the ten percent level over the Galactic history. Stars that originated from the second generation of dissolved or dissolving clusters can be readily identified via distinct light-element signatures such as enhanced N and Na and si…
Five New Hot Jupiter Transits Investigated with Swift-UVOT
Rauscher, Emily; King, George W.; Reynolds, Mark +3 more
Short-wavelength exoplanet transit measurements have been used to probe mass loss in exoplanet atmospheres. We present the Swift-UVOT transit light curves for five hot Jupiters orbiting UV-bright F-type stars: XO-3, KELT-3, WASP-3, WASP-62, and HAT-P-6. We report one positive transit detection of XO-3b and one marginal detection of KELT-3b. We pla…