J/A+AS/127/145 Hamburg/RASS Cat. of optical identifications (HRC) (Bade+, 1998)
The Hamburg/RASS Catalogue of optical identifications.
Bade N., Engels D., Voges W., Beckmann V., Boller T., Cordis L., Dahlem M.,
Englhauser J., Molthagen K., Nass P., Studt J., Reimers D.
<Astron. Astrophys. Suppl. Ser. 127, 145 (1998)>
=1998A&AS..127..145B 1998A&AS..127..145B (SIMBAD/NED BibCode)
ADC_Keywords: X-ray sources ; Galaxy catalogs ; QSOs ; Cross identifications
Keywords: X-ray sources: general - galaxies - stars
Abstract:
We present the Hamburg/RASS Catalogue of optical identifications
(HRC). The catalogue contains optical information about objects inside
the error circles of ROSAT All-Sky Survey (RASS, Cat. IX/10)
sources. The information was gathered from objective prism and direct
plates taken by the Hamburg Quasar Survey (HQS). The plates enable an
effective selection of several X-ray emitting classes of objects, as
there are galaxies, AGN, QSOs, galaxy clusters and several types of
galactic stars, in particular M dwarfs, hot white dwarfs and
cataclysmic variables. In the current state (November 1996) the HRC
contains information about 3847 X-ray positions and covers about
8480deg2 of the high galactic latitude (|b|>20°) northern sky.
For 81.2% of the X-ray sources a plausible optical counterpart is
given. The counterparts of the remaining sources are probably faint
(B>18.5) AGN and galaxy clusters. The HRC is available electronically
together with finding charts taken from the digitized direct HQS
plates.
Description:
The file rassid2.cat provides information on optical identifications
to X-ray positions of the ROSAT All-Sky Survey (RASS). The file was
created by correlating the Bright Source Catalogue of ROSAT (Voges et
al., 1996, Cat. IX/10) and the Hamburg/RASS Catalogue of Optical
Identifications (HRC) (Bade et al., 1996, in prep.). In the current
state (Version 2.0) the catalogue contains 4665 positions in the
extragalactic northern sky. For each X-ray position optical
information taken from HQS objective prism and direct Schmidt plates
(Hagen et al., 1995A&AS..111..195H 1995A&AS..111..195H) is given and a finding chart
derived from digitized direct plates as gzipped Postscript file is
provided (sky.ps file). If possible, the most likely optical
counterpart is marked in the catalogue and on the finding chart. For
many of the newly processed HQS fields of Version 2.0 no direct
Schmidt plates from the HQS exists. In these cases we put finding
charts generated from the STScI Digitized Sky Survey on the ftp
server, ftp.hs.uni-hamburg.de, pub/outgoing/rass-id.
We remind the reader that the STScI Digitized Sky Survey and
HQS prism plates have different epochs. This has to be taken into
account for stellar identifications. Furthermore the spectral
sensitivity of the STScI Digitized Sky Survey and the HQS prism plates
is different. The finding chart for each X-ray position is stored as a
gzipped Postscript file and they can be found in the directories d-10
to d+80 at ftp.hs.uni-hamburg.de, pub/outgoing/rass-id. These
directories arrange the files into declination belts. Names of finding
charts generated by the STScI Digitized Sky Survey begin with a 'p'.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
rassid1.dat 63 3846 X-ray data (V1.1, issued December 5, 1996,
Version of 09/03/2001)
optical1.dat 91 8306 Possible optical counterpart to X-ray sources
of radio.dat
rassid2.dat 63 4664 X-ray data (V2.0, issued January 5, 1998,
Version of 09/03/2001)
optical2.dat 79 10528 Possible optical counterpart to X-ray sources
of radio2.dat
sky.ps 93 31559 RASS II identifications based on Schmitd plates
--------------------------------------------------------------------------------
See also:
J/A+A/406/535 : HRC, V3.0 (Zickgraf+, 2003)
IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
IX/29 : ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000)
J/A+AS/115/235 : The Hamburg/ESO survey for bright QSOs. II. (Reimers+, 1996)
J/A+A/358/77 : The Hamburg/ESO survey for bright QSOs. III (Wisotzki+, 2000)
J/A+AS/128/507 : The Hamburg Quasar Survey. II. (Engels+ 1998)
J/A+AS/134/483 : The Hamburg Quasar Survey. III. (Hagen+ 1999)
Byte-by-byte Description of file: rassid[12].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- RXJ Object name
17- 18 I2 h RAh Right ascension (2000.0)
20- 21 I2 min RAm Right ascension (2000.0)
23- 26 F4.1 s RAs Right ascension (2000.0)
28 A1 --- DE- Declination sign (2000.0)
29- 30 I2 deg DEd Declination (2000.0)
32- 33 I2 arcmin DEm Declination (2000.0)
35- 36 I2 arcsec DES Declination (2000.0)
38- 40 I3 arcsec eRad Error radius derived from the BSC
42- 48 A7 --- Seq Internal number
50- 52 I3 --- IdCode Identification code (1)
54 I1 --- Flag1 [0/1] flag, if set to 1, identification changed
since last catalogue version
55 I1 --- Flag2 [0/1] flag, if set to 1, entries to this X-ray
position have changed since last
catalogue version,
56 I1 --- Flag3 [0/1] flag, supplementary X-ray positions are
flagged with 1
58- 63 I6 "YYMMDD" Date Date of last change (YYMMDD)
--------------------------------------------------------------------------------
Note (1): The identification code is defined as follows:
The first (and third) digit give(s) the classification:
1 : AGN
2 : Galaxy, derived from the morphology on the direct plates
3 : Cluster
5 : M dwarf
6 : White Dwarf
7_1 : K Dwarf
7_2 : F or G star
7_3 : Cataclysmic Variable (CV)
7_4 : Bright Star (B < 13)
8 : no plausible candidate found
803 : one object in favourable position, but no spectral information
0 : empty field on objective prism and direct plate within a
radius of at least 40 arcsec
The second digit in the identification code describes the reliability
of the given identification:
0: 'highly probable', the proposed counterpart fulfills all
requirements of its class and no other plausible counterpart
within the error radius of the X-ray source exists
1: 'probable', the proposed counterpart fulfills the requirements of
its class, but there are limitations. Either, the objective
spectrum is not typical, or there are small conflicts with the
X-ray information (spectral or spatial information, distance to
the X-ray position) or there is another (considerably less)
plausible counterpart in the error circle
2: 'possible', the proposed counterpart fulfills some requirements
of its class, but there are doubts arising from insufficient
objective prism data, conflicting X-ray data or another plausible
candidate
--------------------------------------------------------------------------------
Byte-by-byte Description of file: optical[12].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- RXJ Source name
17 A1 --- Opt [+] +: Proposed optical counterpart
18- 20 I3 --- Seq Possible optical counterpart sequential number
21 A1 --- n_Seq [P]
24- 25 I2 h RAh ? Right ascension (2000.0)
27- 28 I2 min RAm ? Right ascension (2000.0)
30- 33 F4.1 s RAs ? Right ascension (2000.0)
35 A1 --- DE- Declination sign (2000.0)
36- 37 I2 deg DEd ? Declination (2000.0)
39- 40 I2 arcmin DEm ? Declination (2000.0)
42- 43 I2 arcsec DEs [0/60]? Declination (2000.0)
46- 49 I4 arcsec DRA ? X-ray position - optical position
in right ascension
51- 54 I4 arcsec DDE ? X-ray position - optical position
in declination
56- 58 I3 arcsec DDist ? Distance between X-ray and optical position
60 A1 --- l_Bmag Limit flag on Bmag (1)
61- 64 F4.1 mag Bmag ? Optical magnitude B (2)
65 A1 --- n_Bmag [e:]
67- 69 I3 ---- Code ? Code not defined in the original data
71- 79 A9 --- Class Classification for objective prism spectrum (3)
--------------------------------------------------------------------------------
Note (1): a '<' means upper limit for magnitude, the object is saturated
Note (2): '>19.0' in column 59-63 means, that the optical counterpart is only
visible on the direct plate not on the prism plate(s)
no entry means no B magnitude available
Note (3): For the classification of objective prism spectra the following
scheme was adopted:
SUBDWARF: Hot Subdwarfs (sdO,sdB)
W-DWARF : White Dwarfs
STAR-BA : Balmer absorption lines, point-like image
STAR-FG : G-Band, Ca H+K, point-like image
STAR-K : G-Band, Ca H+K, redder continuum, point-like image
STAR-M : Very red, TiO lines, Ca I 4226, point-like image
CV : Cataclysmic variable, Balmer emission lines
GALAXY : Extended image on direct plate, no emission lines,
red continuum
AGN : Emission line(s), blue continuum, weak extension on
direct plate allowed
BLUE GAL: moderately blue continuum, extended image on direct plate
QSO : Emission line(s), extremely blue continuum,
: no extension on direct plate
EBL-WK : Extremely blue continuum, weak point-like object
BLUE-WK : Moderately blue continuum, weak point-like object
RED-WK : Red continuum, weak point-like object
UNIDENT : Classification open
OVERLAP : Classification not possible due to overlapping spectra
SATURATE: Classification not possible due to amplifier saturation
--------------------------------------------------------------------------------
History:
Copied at ftp.hs.uni-hamburg.de, pub/outgoing/rass-id, on 09-Mar-2001
(End) Patricia Bauer [CDS] 09-Mar-2001