Search Publications
Probing Strong Binary Interactions and Accretion in AGB Stars with the ngVLA
Sahai, R.
Understanding strong binary interactions is of wide astrophysical importance, and the deaths of most stars in the Universe that evolve in a Hubble time could be fundamentally affected by such interactions. These stars end their lives, evolving from Asymptotic Giant Branch (AGB) stars with extensive mass-loss into planetary nebulae with a spectacul…
Intermittency spectra of current helicity in solar active regions
Zhang, Hongqi; Abramenko, V. I.; Kuzanyan, K. M. +2 more
We analyse the spatial distribution of current helicity in solar active regions. A comparison of current helicity maps derived from three different instruments (Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, SDO/HMI, Spectro-Polarimeter on board the Hinode, and Solar Magnetic Field Telescope at the Huairou Solar Observin…
Polarimetric and spectroscopic study of radio-quiet weak emission line quasars
Stalin, C. S.; Petitjean, P.; Srianand, R. +3 more
A small subset of optically selected radio-quiet quasars showing weak or no emission lines may turn out to be the elusive radio-quiet BL Lac objects, or simply be radio-quiet QSOs with a still-forming/shielded broad line region (BLR). High polarization (p > 3-4 per cent), a hallmark of BL Lacs, can be used to test whether some optically selecte…
Non-Gaussianity and cross-scale coupling in interplanetary magnetic field turbulence during a rope-rope magnetic reconnection event
Miranda, Rodrigo A.; Chian, Abraham C. -L.; Schelin, Adriane B. +1 more
In a recent paper (Chian et al., 2016) it was shown that magnetic reconnection at the interface region between two magnetic flux ropes is responsible for the genesis of interplanetary intermittent turbulence. The normalized third-order moment (skewness) and the normalized fourth-order moment (kurtosis) display a quadratic relation with a parabolic…
Multilayer mirror-based soft x-ray polarimeter for astronomical observations
Marshall, Herman L.; Narendranath, Shyama; Panini, Singam S. +3 more
A simple design of a soft x-ray polarimeter using multilayer mirrors is presented. A multilayer mirror acts as a linear polarization analyzer for x-rays at incidence angles close to the Brewster angle. The instrument consists of an x-ray concentrator, a set of multilayer mirrors placed at 45 deg from the optical axis, and a detector at Nasmyth foc…
Statistical survey of day-side magnetospheric current flow using Cluster observations: bow shock
Glassmeier, Karl-Heinz; Liebert, Evelyn; Nabert, Christian
We present the first comprehensive statistical survey of the day-side terrestrial bow shock current system based on a large number of Cluster spacecraft bow shock crossings. Calculating the 3-D current densities using fluxgate magnetometer data and the curlometer technique enables the investigation of current locations, directions, and magnitudes …
In-flight performance of the Canadian Astro-H Metrology System
Ishida, Manabu; Iizuka, Ryo; Gallo, Luigi C. +11 more
The Canadian Astro-H Metrology System (CAMS) on the Hitomi x-ray satellite is a laser alignment system that measures the lateral displacement (X/Y) of the extensible optical bench (EOB) along the optical axis of the hard x-ray telescopes (HXTs). The CAMS consists of two identical units that together can be used to discern translation and rotation …
Verification of Photometric Parallaxes with Gaia DR2 Data
Zhao, Gang; Karpov, Sergey; Sytov, Alexey +10 more
Results of comparison of Gaia DR2 parallaxes with data derived from a combined analysis of 2MASS (Two Micron All-Sky Survey), SDSS (Sloan Digital Sky Survey), GALEX (Galaxy Evolution Explorer), and UKIDSS (UKIRT Infrared Deep Sky Survey) surveys in four selected high-latitude |b|> 48° sky areas are presented. It is shown that multicolor photome…
Global structure of the heliosphere: 3D kinetic-MHD model and the interpretation of spacecraft data
Izmodenov, V. V.
This paper is a brief overview of research into the interaction between the solar wind and local interstellar medium. This interaction determines the global structure of the heliosphere (the region occupied by the solar wind) and has a complex multicomponent character. We describe the three-dimensional kinetic-magnetohydrodynamic model of the inte…
Can the relativistic light-bending model explain X-ray spectral variations of Seyfert galaxies?
Tsujimoto, Masahiro; Ebisawa, Ken; Mizumoto, Misaki +3 more
Many Seyfert galaxies are known to exhibit Fe-K broad emission line features in their X-ray energy spectra. The observed lines have three distinct features: (1) the line profiles are skewed and show significant low-energy tails, (2) the Fe-K band has low variability, which produces a broad and deep dip in the root-mean-square (rms) spectra, and (3…