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A ROSAT medium-sensitivity Galactic plane survey at 180°< l < 280°
We have performed a moderately deep soft X-ray (0.1-2keV) survey of theGalactic plane using pointed observations with the ROSAT PositionSensitive Proportional Counter (PSPC). The survey is more than an orderof magnitude more sensitive than previous X-ray surveys near theGalactic plane. The data consist of nine fields each of ~10ks exposure,pointed at positions on or very close to the Galactic plane(|b|<0°.3) in the longitude range 180°<~l<~280°.This region has relatively low X-ray absorbing material out to distancesof several hundred pc and presents fewer source-confusion problems thanat other longitudes. The total sky area surveyed was 2.5deg2this yielded 93 sources, 89 of which were detected in the `hard'(0.4-2.0keV) band. Nine sources were detected in both `soft'(0.1-0.4keV) and hard bands. In the hard band, the survey coverage is>~90 per cent for sources brighter than 0.002counts-1(~2×10-14ergcm-2s-1), but fallssteeply below this value, with the weakest sources being~0.001counts-1. The median limiting flux is~0.0013counts-1(~1.3×10-14ergcm-2s-1). There are64 sources with hard-band count rates >0.002counts-1. Wepresent the catalogue of X-ray sources and the number-flux relations(logN-logS). Eighteen sources have possible identifications from theSIMBAD data base. We have searched the Tycho-2 and USNO-A2.0 cataloguesto find all possible optical counterparts brighter than ~19th magnitude,and attempt to classify these on the basis oflog(fX/fopt) versus optical colour diagrams andnear-infrared photometry from the 2MASS Second Incremental Data Release.Hence, we have found the majority of these sources to be consistent withbeing late-type main-sequence stars, as previous studies have proposedfrom incompletely identified surveys. Comparison of the measurednumber-flux relations with predictions of Galactic (stellar) andextragalactic populations supports the view that the population of youngstars in the plane is denser than previously thought.
| 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.
| La mesure des vitesses radiales au prisme objectif - X - 4e liste de vitesses radiales déterminées au prisme objectif à vision directe
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| Сазвежђа: | Једнорог |
| Ректацензија: | 06h41m36.06s |
| Deклинација: | +04°28'51.6" |
| Apparent магнитуда: | 8.686 |
| Proper motion RA: | -3.4 |
| Proper motion Dec: | -36.2 |
| B-T magnitude: | 9.097 |
| V-T magnitude: | 8.72 |
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