Search Publications
Optical Emission Lines and the X-ray Properties of Type 1 Seyfert Galaxies
Popović, L. Č.; La Mura, G.; Ciroi, S. +3 more
In this contribution we report on the study of the optical emission lines and X-ray spectra of a sample of Type 1 AGNs, collected from the SDSS database and observed by the XMM-Newton satellite. Using different instruments onboard XMM, we identify the spectral components of the soft and hard energy bands (in the range from 0.3 keV to 10 keV). The …
Hints on the Broad Line Region Structure of Quasars at High and Low Luminosities
Sulentic, Jack W.; Marziani, Paola; Dultzin, Deborah +2 more
Quasars show a considerable spectroscopic diversity. However, the variety of quasar spectra at low redshifts is non-random: a principal component analysis applied to large samples customarily identifies two main eigenvectors. In this contribution we show that the range of quasar optical spectral properties observed at low-z\ and associated with th…
Young Stars in the Camelopardalis Dust and Molecular Clouds. VI. YSOs Verified by Spitzer and Akari Infrared Photometry
Straižys, V.; Kazlauskas, A.
Using photometric data of infrared surveys, young stellar object (YSO) status is verified for 141 objects selected in our previous papers in the Cassiopeia and Camelopardalis segment of the Milky Way bounded by Galactic coordinates (ℓ, b) = (132--158°, ±12°). The area includes the known star-forming regions in the emission nebulae W3, W4 and W5 an…
X-Ray Emission of Cataclysmic Variables Observed by Integral
Paltani, S.; Gális, R.; Eckert, D. +2 more
Magnetic cataclysmic variables represent a significant fraction of all INTEGRAL detections in hard X-rays and soft gamma rays. Our deep survey of all known intermediate polars revealed five new sources, previously undetected by this mission. Our analysis, based on all available observational data from the IBIS and JEM-X instruments, has shown that…
Global Characteristics of Gamma-Ray Bursts Observed with INTEGRAL
McGlynn, S.; McBreen, S.; Foley, S. +5 more
The gamma-ray instruments on board INTEGRAL have detected and localized 62 gamma-ray bursts (GRBs) to date. The peak flux distribution of these bursts shows that INTEGRAL detects proportionally more weak GRBs than Swift because of its higher sensitivity in a smaller field of view. Spectral lags, i.e., the time delay in the arrival of low-energy ga…
Blazars with Integral
Pian, E.; Hudec, R.; Blažek, M. +1 more
The analysis of the INTEGRAL data for blazars, a specific class of the active galactic nuclei, is described. These objects are promising objects for observations by INTEGRAL, especially during their active states. A strategy for their future investigation is proposed and discussed.
Flare Loop Sizes in Young Suns
Schultz, J.; Nevalainen, J.; Väänänen, M. K.
We analyse 27 solar flares observed with GOES and RHESSI in the X-ray bands at 3.1--24.8 keV and 12--25 keV and in Hα . The flaring region diameter in X-rays is found to correlate with the Hα decay duration, and this correlation is used to approximate the flare loop semilength. We propose the method to measure the coronal loop semilengths in young…
Suzaku Observation of Igr J16318-4848
Pottschmidt, Katja; Wilms, Jörn; Kreykenbohm, Ingo +3 more
IGR J16318-4848 is the first example of a new class of highly absorbed X-ray binaries that has been discovered by INTEGRAL. We analyzed the first Suzaku observation of this source (2006 August 14--17), and obtained a spectrum that can be well described by an absorption model (TBabs) and a cutoff powerlaw, plus the Gaussians for the emission lines …
Czech Participation in Integral
Hudec, R.; Blažek, M.; Kocka, M. +1 more
The INTEGRAL gamma-ray observatory, launched in October of 2002, is the first astrophysical mission of the European Space Agency with the Czech participation. Here we present and discuss the results of our investigations of cataclysmic variables, blazars, X-ray sources and GRBs obtained during the first six years of the mission.
Web-Based Approach to the Integral Data
Münz, Filip; Kocka, Matúš
Our extensive exploration of the INTEGRAL data in gamma and X-ray domains had two principal aims: to cover as many sources of chosen categories as possible (with sufficient upper limits of their fluxes) and to check for their eventual variability. This means treating a large number of time-resolved results that can be most easily approached using …