Search Publications
Peak of spectral energy distribution plays an important role in intra-day variability of blazars?
Gupta, Alok C.; Kalita, Nibedita; Gaur, Haritma +1 more
Blazars can be divided into two sub-classes namely high energy and low energy peaked blazars. In spectral energy distribution, the first synchrotron hump of the former class peaks in UV/X-rays and in IR/optical bands for the latter class. The peak of the spectral energy distribution seems to be responsible for variability properties of these class…
A pair of O VI and broad Ly α absorbers probing warm gas in a galaxy group environment at z ∼ 0.4
Savage, Blair D.; Wakker, Bart P.; Muzahid, Sowgat +4 more
We report the detection of two O VI absorbers at z = 0.416 14 and 0.419 50 (|Δv| = 710 km s-1), towards SBS 0957+599. Both absorbers are multiphase systems tracing substantial reservoirs of warm baryons. The low- and intermediate-ionization metals in the z = 0.416 14 absorber are consistent with an origin in photoionized gas. O VI has a…
Sources of the Slow Solar Wind During the Solar Cycle 23/24 Minimum
Madjarska, M. S.; Kilpua, E. K. J.; Wiegelmann, T. +4 more
We investigate the characteristics and the sources of the slow (<450 kms−1) solar wind during the four years (2006 - 2009) of low solar activity between Solar Cycles 23 and 24. We used a comprehensive set of in-situ observations in the near-Earth solar wind (Wind and ACE) and removed the periods when large-scale interplanetary corona…
Molecule survival in magnetized protostellar disk winds. II. Predicted H2O line profiles versus Herschel/HIFI observations
Ferreira, J.; Pineau des Forêts, G.; Cabrit, S. +1 more
Context. The origin of molecular protostellar jets and their role in extracting angular momentum from the accreting system are important open questions in star formation research. In the first paper of this series we showed that a dusty magneto-hydrodynamic (MHD) disk wind appeared promising to explain the pattern of H2 temperature and …
A classification of martian gullies from HiRISE imagery
Auld, Katherine S.; Dixon, John C.
Due to the large and varied population of gullies observed in Mars High Resolution Imaging Science Experiment (HiRISE) imagery that exhibit diverse characteristics, this paper develops a classification of martian gullies based on their morphological characteristics. This provides a firmer foundation for future investigation of the genesis of diffe…
Origin and evolution of two-component debris discs and an application to the q1 Eridani system
Kirchschlager, Florian; Booth, Mark; Krivov, Alexander V. +3 more
Many debris discs reveal a two-component structure, with an outer Kuiper-belt analogue and a warm inner component whose origin is still a matter of debate. One possibility is that warm emission stems from an `asteroid belt' closer in to the star. We consider a scenario in which a set of giant planets is formed in an initially extended planetesimal…
Comparison between 2D and 3D Parameters of 306 Front-side Halo CMEs from 2009 to 2013
Cho, K. -S.; Moon, Y. -J.; Jang, Soojeong +2 more
We investigate 306 LASCO front-side halo (partial and full) CMEs from 2009 to 2013, which are well-observed by both the Solar and Heliospheric Observatory (SOHO) and the Solar TErrestrial RElations Observatory (STEREO). These CMEs have two-dimensional (2D) parameters, such as speed, angular width, and propagation direction, from a single spacecraf…
X-ray, UV and optical analysis of supergiants: ɛ Ori
Hillier, D. John; Leutenegger, Maurice A.; Cohen, David H. +2 more
We present a multi-wavelength (X-ray to optical) analysis, based on non-local thermodynamic equilibrium photospheric+wind models, of the B0 Ia-supergiant: ɛ Ori. The aim is to test the consistency of physical parameters, such as the mass-loss rate and CNO abundances, derived from different spectral bands. The derived mass-loss rate is {dot {M}} / …
No Evidence of Intrinsic Optical/Near-infrared Linear Polarization for V404 Cygni during Its Bright Outburst in 2015: Broadband Modeling and Constraint on Jet Parameters
Morokuma, T.; Cheung, C. C.; Fukazawa, Y. +39 more
We present simultaneous optical and near-infrared (NIR) polarimetric results for the black hole binary V404 Cyg spanning the duration of its seven-day-long optically brightest phase of its 2015 June outburst. The simultaneous R- and K s -band light curves showed almost the same temporal variation except for the isolated (∼30-minute dur…
Evolution of the X-Ray Properties of the Transient Magnetar XTE J1810-197
Halpern, J. P.; Alford, J. A. J.
We report on X-ray observations of the 5.54 s transient magnetar XTE J1810-197 using the XMM-Newton and Chandra observatories, analyzing new data from 2008 through 2014, and re-analyzing data from 2003 through 2007 with the benefit of these six years of new data. From the discovery of XTE J1810-197 during its 2003 outburst to the most recent 2014 …