Ýçindekiler
Görüntüler
Resim Yükleyin
DSS Images Other Images
Ýlgili Makaleler
The Second Byurakan Survey. General Catalogue
The Second Byurakan Survey (SBS) General Catalogue is presented. TheSBS, a continuation of the Markarian survey reaching fainter limitingmagnitudes, is the first survey which combines the search of galaxiesand QSOs. A total area of 991OS#square;degrees of the Northern sky wascovered with the use of three objective prisms in combination withSchott filters. The limited magnitude on the best plates reached B ~19.5.The General Catalogue consists of 3563 objects presented in two parts: aCatalogue of galaxies (1863 objects) and one of stellar objects (1700objects). The Catalogue of SBS AGN consists of 761 objects (155 SyG, 596QSOs, and 10 BLLac). Multi-wavelength data are presented for 1438 SBSobjects identified with X-ray, IRAS and FIRST sources.Spectrophotometric observations obtained over 26 years are available for3132 objects. Redshifts were measured for ~ 2100 extragalactic objects.Spectral classification is presented for ~ 2970 objects. The majority ofthe data is presented here for the first time. The Catalogue presentsnew large homogeneous deep representative complete samples of brightQSOs, AGNs, and faint UVX galaxies in the Northern sky. The SBS sampleis found to be complete at 70% for galaxies and ~ 85% for AGN/QSOs withB ≤ 17.5.
| Mechanisms of the Vertical Secular Heating of a Stellar Disk
We investigate the nonlinear growth stages of the bending instability instellar disks with exponential radial density profiles. We found thatthe unstable modes are global (the wavelengths are larger than the diskscale lengths) and that the instability saturation level is much higherthan that following from a linear criterion. The instability saturationtime scales are of the order of one billion years or more. For thisreason, the bending instability can play an important role in thesecular heating of a stellar disk in the z direction. In an extensiveseries of numerical N-body simulations with a high spatial resolution,we were able to scan in detail the space of key parameters (the initialdisk thickness z_0, the Toomre parameter Q, and the ratio of dark halomass to disk mass M_h/M_d). We revealed three distinct mechanisms ofdisk heating in the z direction: bending instability of the entire disk,bending instability of the bar, and heating on vertical inhomogeneitiesin the distribution of stellar matter.
| The second Kiso Survey for ultraviolet-excess galaxies. II.
Not Available
| Slit spectra of galaxies from the Second Byurakan Sky Survey. IX.
Not Available
| Accurate optical positions for 2978 objects from the Second Byurakan Survey (SBS) with the Digitized Sky Survey
Optical positions of 2978 objects listed in the Second Byurakan Survey(SBS) were obtained using the Digitized Sky Survey (DSS), and are givenwith an rms uncertainty ~ 1 arcsec in each coordinate. Tables 1 and 2are only available in electronic form at the CDS via anonymous ftp130.79.128.5 or via http://cdsweb.u-strasbg.fr/Abstract.html
| Galaxy coordinates. II. Accurate equatorial coordinates for 17298 galaxies
Using images of the Digitized Sky Survey we measured coodinates for17298 galaxies having poorly defined coordinates. As a control, wemeasured with the same method 1522 galaxies having accurate coordinates.The comparison with our own measurements shows that the accuracy of themethod is about 6 arcsec on each axis (RA and DEC).
|
Yeni bir Makale Öner
Ýlgili Baðlantýlar
Yeni Bir Baðlantý Öner
sonraki gruplarýn üyesi:
|
Gözlemler ve gökölçümü verileri
Kataloglar ve belirtme:
|
