目录
图像
上传图像
DSS Images Other Images
相关文章
Spectral Classification of Stars in A Supplement to the Bright Star Catalogue
MK spectral types are given for about 584 stars in A Supplement to theBright Star Catalogue. These are compared with Hipparcos parallaxes tocheck the reliability of those classifications. The estimated errors are+/-1.2 subtypes, and 10% of the luminosity classes may be wrong.
| A Candidate of a Type 2 Quasi-stellar Object at z=0.9: Large X-Ray Absorption with a Strong Broad Hα Emission Line
Deep hard X-ray and near-infrared observations of a type 2 radio-quietquasi-stellar object (QSO) candidate at z=0.9, AX J08494+4454, arereported. The 0.5-10 keV Chandra X-Ray Observatory spectrum of AXJ08494+4454 is hard and is explained well with a power-law continuumabsorbed by a hydrogen column density of(2.3+/-1.1)×1023 cm-2. The 2-10 keVluminosity of the object is estimated to be7.2+3.6-2.0×1044 ergss-1, after correcting the absorption, and reaches hard X-rayluminosities of QSOs. The large X-ray absorption and the large intrinsicluminosity support the original identification of AX J08494+4454 as atype 2 radio-quiet QSO. Nevertheless, the deep Subaru/IRCS J-bandspectroscopic observation suggests the presence of a strong broadHα emission line from AX J08494+4454. If real, the broad Hαemission line has a velocity width of 9400+/-1000 km s-1,which corresponds to a typical broad Balmer line velocity width of aluminous QSO. The existence of the strong broad Hα line means thatthe object is not a type 2 QSO but a luminous cousin of a Seyfert 1.9galaxy in the source-frame optical spectrum. The Balmer decrement ofbroad lines and the broad Hα emission to the hard X-ray luminosityratio suggest that the nucleus is affected by dust extinction with anAV of 1-3 mag in the optical wavelength. Optical colors andfaint optical magnitudes of AX J08494+4454 are consistent with themodel. The estimated amount of dust extinction is much smaller than thatexpected from the X-ray column density (AV=130+/-60 mag).Based on data collected at the Subaru Telescope, which is operated bythe National Astronomical Observatory of Japan, and University of Hawaii2.2 m Telescope.
| UvbyHbeta_ photometry of main sequence A type stars.
We present Stroemgren uvby and Hbeta_ photometry for a set of575 northern main sequence A type stars, most of them belonging to theHipparcos Input Catalogue, with V from 5mag to 10mag and with knownradial velocities. These observations enlarge the catalogue we began tocompile some years ago to more than 1500 stars. Our catalogue includeskinematic and astrophysical data for each star. Our future goal is toperform an accurate analysis of the kinematical behaviour of these starsin the solar neighbourhood.
| Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
| Final catalogue of 229 photometric standards in UBV system near the selected areas 1-115
Not Available
| A Finding List of Early-Type Stars in Regions of Intermediate Galactic Latitude
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1969ApJ...157..327U&db_key=AST
| The corrected magnitudes and colours of 278 stars near S.A. 1-139 in the UBV system
Not Available
|
提交文章
相关链接
提交链接
下列团体成员
|
观测天体数据
目录:
|
