@misc{Paronyan_G._M._Activity,
 author={Paronyan, G. M. and Mickaelian, A. M. and Abrahamyan, H. V. and Mikayelya, G. A. and Sukiasyan, A. G. and Mkrtchyan, V. K. and Gasparyan, A. A.},
 howpublished={online},
 abstract={We have created a general catalogue of AGN selected from optical identifications of X-ray sources using two sources: Hamburg-ROSAT Catalogue (HRC) and Byurakan-Hamburg-ROSAT Catalogue (BHRC). Both contain optical identifications of X-ray sources from ROSAT catalogues based on low-dispersion spectra of Hamburg Quasar Survey (HQS). HRC used ROSAT Bright Source Catalogue (BSC) and BHRC used brighter sources of ROSAT Faint Source Catalogue (FSC), thus extending the sample to count rates (CR) of photons ≥ 0.04 ct/s in the area with galactic latitudes |b| ≥ 20◦ and declinations δ ≥ 0◦ (the area of HQS). However, HRC and BHRC contain a number of misidentifications, and by using the recent optical and multiwavelength (MW) catalogues we have revised both samples excluding false AGN and adding new genuine AGN. As a result, a new homogeneous complete sample of 4253 X-ray selected AGN was created (ROSAT BSC/FSC AGN). For these sources we retrieved all multiwavelength data from recent catalogues and carried out statistical investigations. An attempt to find connections between the radiation fluxes in different bands for different types of sources, and identify their characteristics thus confirming candidate AGNs have been done. We have analyzed X-ray properties of these sources to find a limit between normal galaxies and X-ray AGN. In this study we carry out detailed spectral classification of AGN candidates from the Joint HRC/BHRC sample. These objects were revealed as optical counterparts for ROSAT X-ray sources, however spectra of them are given in SDSS without definite spectral classification. We studied these objects using the SDSS spectra and revealed the detailed activity types for them. Three diagnostic diagrams and direct examination of the spectra were used to have more confident classification.},
 title={Activity types of x-ray selected galaxies},
 type={Electronic journal},
 keywords={Astrometry, Space Sciences, Archaeoastronomy and Astronomy in Culture},
}