Search Publications
Orbital X-ray modulation study of three supergiant HMXBs
Paul, Biswajit; Jain, Chetana; Dutta, Anjan
We present the orbital X-ray modulation study of three high mass X-ray binary systems, IGR J18027-2016, IGR J18483-0311 and IGR J16318-4848, using data obtained with RXTE-ASM, Swift-BAT and INTEGRAL-ISGRI. Using the long term light curves of the eclipsing HMXB IGR J18027-2016, obtained with Swift-BAT in the energy range 15-50 keV and INTEGRAL-ISGR…
Titan's plasma environment during a magnetosheath excursion: Real-time scenarios for Cassini's T32 flyby from a hybrid simulation
Coates, A. J.; Dougherty, M. K.; Saur, J. +5 more
With a Saturnian magnetopause average stand-off distance of about 21 planetary radii, Titan spends most of its time inside the rotating magnetosphere of its parent planet. However, when Saturn's magnetosphere is compressed due to high solar wind dynamic pressure, Titan can cross Saturn's magnetopause in the subsolar region of its orbit and therefo…
An Imaging and Spectroscopic Study of Four Strong Mg II Absorbers Revealed by GRB 060418
Bloom, J. S.; Prochaska, J. X.; Chen, H. -W. +1 more
We present results from an imaging and spectroscopic study of four strong Mg II absorbers of W(2796) gsim 1 Å revealed by the afterglow of GRB 060418 at z GRB = 1.491. These absorbers, at z = 0.603, 0.656, 1.107, and z GRB, exhibit large ion abundances that suggest neutral gas columns characteristic of damped Lyα systems. The…
The Inconvenient Truth About Coronal Dimmings
McIntosh, Scott W.
We investigate the occurrence of a coronal mass ejection (CME)-driven coronal dimming using unique high-resolution spectral images of the corona from the Hinode spacecraft. Over the course of the dimming event, we observe the dynamic increase of nonthermal line broadening in the 195.12 Å emission line of Fe XII as the corona opens. As the corona b…
Magnetic field and electric currents in the vicinity of polar cusps as inferred from Polar and Cluster data
Tsyganenko, N. A.
A detailed statistical study of the magnetic structure of the dayside polar cusps is presented, based on multi-year sets of magnetometer data of Polar and Cluster spacecraft, taken in 1996-2006 and 2001-2007, respectively. Thanks to the dense data coverage in both Northern and Southern Hemispheres, the analysis spanned nearly the entire length of …
Structure of self-gravity wakes in Saturn's A ring as measured by Cassini CIRS
Leyrat, C.; Ferrari, C.; Spilker, L. +3 more
The CIRS infrared spectrometer onboard the Cassini spacecraft has scanned Saturn's A ring azimuthally from several viewing angles since its orbit insertion in 2004. A quadrupolar asymmetry has been detected in this ring at spacecraft elevations ranging between 16° to 37°. Its fractional amplitude decreases from 22% to 8% from 20° to 37° elevations…
Association of phyllosilicates and the inverted channel in Miyamoto crater, Mars
Wiseman, S. M.; McGuire, P. C.; Marzo, G. A. +4 more
The western floor of the Miyamoto crater in Sinus Meridiani on Mars exhibits both geomorphic and spectral evidence for aqueous history. It contains a sinuous and narrow ridge that is interpreted to be an inverted channel and is suggestive of past fluvial activity. Phyllosilicates occur in materials that are proximal to the paleochannel, but are no…
Determining ion production rates near Saturn's extended neutral cloud from ion cyclotron wave amplitudes
Russell, C. T.; Tokar, R. L.; Omidi, N. +2 more
Recent Cassini observations of active venting of water molecules from Enceladus indicate that the moon is the primary source of Saturn's extended neutral cloud. Ionization of the neutrals through charge exchange creates a population of newborn ions with a velocity space distribution, which is highly unstable to the generation of electromagnetic io…
Determining the Galactic Halo's Emission Measure from UV and X-Ray Observations
Lei, Shijun; Henley, David B.; Shelton, Robin L.
We analyze a pair of Suzaku shadowing observations in order to determine the X-ray spectrum of the Galaxy's gaseous halo. Our data consist of an observation toward an absorbing filament in the southern Galactic hemisphere and an observation toward an unobscured region adjacent to the filament. We simultaneously fit the spectra with models having h…
SDSS absolute magnitudes for thin-disc stars based on trigonometric parallaxes
Cabrera-Lavers, A.; Bilir, S.; Yaz, E. +3 more
We present a new luminosity-colour relation based on trigonometric parallaxes for thin-disc main-sequence stars in Sloan Digital Sky Survey (SDSS) photometry. We matched stars from the newly reduced Hipparcos catalogue with the ones taken from Two-Micron All-Sky Survey (2MASS) All-Sky Catalogue of Point Sources, and applied a series of constraints…