Search Publications
Contribution of Unresolved Point Sources to the Diffuse X-ray Background Below 1 keV
Gupta, A.; Galeazzi, M.
We present here the analysis of X-ray point sources detected in several observations available in the XMM-Newton public archive. We focused, in particular, on energies below 1 keV, which are of particular relevance to the understanding of the diffuse X-ray background (DXB). The average field of all the exposures is 0.09 deg-2. We reache…
X-Ray Absorption and Optical Extinction in the Partially Obscured Seyfert Nucleus in Mrk 1393
Grupe, D.; Wang, T. G.; Yuan, W. +3 more
We present a detailed study of the X-ray and optical spectra of the luminous Seyfert galaxy Mrk 1393, which revealed variable partial obscuration of the active nucleus. The X-ray spectra obtained by XMM-Newton and Swift show moderate absorption with a column density around 3 × 1021 cm-2, consistent with a dust-reddening inter…
A lensing view on the Fundamental Plane
Leier, Dominik
For lensing galaxies, we introduce a formal velocity dispersion σlens, based on enclosed mass and the virial theorem. This is calculated from an ensemble of pixelated lens models, and found to be fairly model-independent. A sample of 18 well-known early-type lensing galaxies and two clusters is found to be consistent with σlens
INTEGRAL observations of the Perseus cluster
Paltani, S.; Eckert, D.
We present the results of a 500 ks observation of the Perseus cluster with INTEGRAL, with the aim of investigating the possible diffuse non-thermal component detected in a previous Chandra observation. In the 3-20 keV band with the JEM-X instrument, we detect the source with high significance and resolve it spatially. Above 20 keV with IBIS/ISGRI,…
Constraints on the Structure of the Heliospheric Interface Based on Ly α Absorption Spectra
Wood, Brian E.; Izmodenov, Vladislav V.; Malama, Yury G.
Spectroscopic observations of the hydrogen Ly α lines from nearby stars taken by the Hubble Space Telescope (HST) sometimes show absorption signatures from the heliosphere. This absorption is a unique diagnostic of material in the outermost parts of our heliosphere. We summarize how the HST data have been used to test various models of the heliosp…
Study of the 28 October 2003 and 20 January 2005 solar flares by means of 2.223 MeV gamma-emission line
Troitskaia, Evgenia V.; Arkhangelskaja, Irene V.; Miroshnichenko, Leonty I. +1 more
By the data on intensity-time profiles of the neutron capture line of 2.223 MeV we have studied some characteristics of two solar flares, 28 October 2003 and 20 January 2005 (INTEGRAL and CORONAS-F observations, respectively). The SINP code was applied making allowance for the main processes of neutron interactions and deceleration in the solar pl…
On the error estimation of multi-spacecraft timing method
Zhang, H.; Zong, Q. -G.; Fu, S. Y. +4 more
The multi-spacecraft timing method, a data analysis technique based on four-point measurements to obtain the normal vector and velocity of an observed boundary, has been widely applied to various discontinuities in the solar wind and the magnetosphere studies. In this paper, we perform simulations to analyze the errors of the timing method by spec…
SCUBA Observations of Early-Type Galaxies
Fich, Michel; Savoy, Jonathan; Welch, Gary A.
We present SCUBA observations of the emission of 23 E and S0 galaxies at wavelengths of 850 and 450 µm. Four galaxies are detected at 850 µm with signal-to-noise ratios above 3.0, and an additional galaxy, NGC 6524, is detected at both 850 and 450 µm. We use the SCUBA data with published optical and IRAS photometry to construct s…
Rosetta swing-by at Mars - an analysis of the ROMAP measurements in comparison with results of 3-D multi-ion hybrid simulations and MEX/ASPERA-3 data
Lundin, R.; Fränz, M.; Edberg, N. J. T. +8 more
The Rosetta spacecraft flew by Mars at a distance of 260 km on 25 February 2007 during a gravity assist manoeuvre. During the closest approach (CA) the lander magnetometer ROMAP was switched on. The dataset taken during this swingby provides insight into the plasma environment around Mars: in addition to a pronounced bow shock crossing Rosetta rec…
Characterization of Active Galactic Nuclei and Their Hosts in the Extended Groth Strip: A Multiwavelength Analysis
Pérez-González, P. G.; Ramos Almeida, C.; Gallego, J. +2 more
We have employed a reliable technique of classification of active galactic nuclei (AGNs) based on the fit of well sampled spectral energy distributions (SEDs) with a complete set of AGN and starburst galaxy templates. We have compiled UV, optical, and IR data for a sample of 116 AGNs originally selected for their X-ray and mid-IR emissions (96 wit…