Search Publications
X-Raying the Coronae of HD 155555
Singh, K. P.; Lalitha, S.; Kashyap, V. +1 more
We present an analysis of the high-resolution Chandra observation of the multiple system, HD 155555 (an RS Canum Venaticorum; RS CVn type binary system, HD 155555 AB, and its spatially resolved low-mass companion HD 155555 C). This is an intriguing system that shows properties of both an active pre-main-sequence star and a synchronized (main seque…
Suzaku and Fermi observations of the supernova remnant G1.9 + 0.3
Gök, Fatma; Ergin, Tülün
We present results from the observation of the supernova remnant (SNR) G1.9 + 0.3, which is the youngest known SNR in the Milky Way, with the X-ray imaging spectrometer (XIS) on board Suzaku. We investigate the nature of the X-ray emission and compare our results with the previous X-ray studies. Additionally, we present the analysis results of the…
Synchrotron emission model of gamma-ray pulsar PSR J2021+3651
Chkheidze, N.; Babyk, Iu.
In the present paper a self-consistent theory, interpreting the high energy gamma-ray and X-ray observations of pulsar PSR J2021+3651 performed by Fermi-LAT, XMM-Newton and Chandra space telescopes are considered. It is shown that the photon spectrum between 0.1 keV and 25 GeV can be well described by a power-law function with the spectral index Γ…
On the diffuse soft X-ray emission from the nuclear region of M51
Mao, Shu-De; Liu, Ji-Ren
We present an analysis of the diffuse soft X-ray emission from the nuclear region of M51 combining both XMM-Newton RGS and Chandra data. Most of the RGS spectrum of M51 can be fitted with a thermal model with a temperature of ∼ 0.5 keV except for the O VII triplet, which is forbidden-line dominated. The Fe L-shell lines peak around the southern cl…
Chandra and XMM-Newton Observations of the Merging Cluster of Galaxies PLCK G036.7+14.9
Dahle, H.; Arnaud, M.; Pointecouteau, E. +13 more
We present Chandra and XMM-Newton observations of PLCK G036.7+14.9 from the Chandra-Planck Legacy Program. The high resolution X-ray observations reveal two close (∼72″ = 193 kpc in projection) subclusters, G036N and G036S, which were not resolved by previous ROSAT, optical, or recent Planck observations. We perform detailed imaging and spectral a…
The Short Bursts in SGR 1806-20, 1E 1048-5937, and SGR 0501+4516
Chen, Yupeng; Zhang, Shu; Ji, Long +4 more
We analyzed temporal and spectral properties, focusing on the short bursts, for three anomalous X-ray pulsars (AXPs) and soft gamma repeaters (SGRs), including SGR 1806-20, 1E 1048-5937 and SGR 0501+4516. Using the data from XMM-Newton, we located the short bursts by Bayesian blocks algorithm. The short bursts' duration distributions for three sou…
Spectroscopic Studies of an Ultraluminous Supersoft X-Ray Source in M81
Bai, Yu; Wang, Song; Liu, JiFeng
Ultraluminous supersoft X-ray sources (ULSs) exhibit supersoft X-ray spectra with blackbody temperatures below 0.1 keV and bolometric luminosities above 1039 ergs s-1. In this Letter, we report the first optical spectroscopic observations of a ULS in M81 using the LRIS spectrograph on the Keck I telescope. The detected Balmer…
On the origin of the iron fluorescent line emission from the Galactic Ridge
Eze, R. N. C.
The Galactic Ridge X-ray Emission (GRXE) spectrum has strong iron emission lines at 6.4, 6.7, and 7.0 keV, each corresponding to the neutral (or low-ionized), He-like, and H-like iron ions. The 6.4 keV fluorescence line is due to irradiation of neutral (or low ionized) material (iron) by hard X-ray sources, indicating uniform presence of the cold …
Morphology and Structure of Ultraluminous Infrared Galaxies at z ∼ 2 in the EGS Field
Kong, Xu; Chen, Yang; Fang, Guan-Wen +1 more
Using the high-resolution F160W images observed by the HST WFC3 (Hubble Space Telescope Wide Field Camera 3) in the CANDELS-EGS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Extended Groth Strip) field, we have studied the morphological and structural features of 9 ultraluminous infrared galaxies (ULIRGs) at z ∼ 2. We find a wide…
Solar and Galactic Cosmic Rays Observed by SOHO
Curdt, W.; Fleck, B.
Both the Cosmic Ray Flux (CRF) and Solar Energetic Particles (SEPs) have left an imprint on SOHO technical systems. While the solar array efficiency degraded irreversibly down to ≈77% of its original level over roughly 1 1/2 solar cycles, Single Event Upsets (SEUs) in the solid state recorder (SSR) have been reversed by the memory protection mecha…