ACDS V10.0 - Thu Dec 21 13:54:32 CET 2023
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Detailed Description of IX/29 :
ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000)
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Note : this is the description file of the original catalog.
This HTML page corresponds well to the original description, but some minor
changes in the format may have been introduced in the FITS output
files in order to allow for arithmetic operations on quantities
such as coordinates and times. h:m:s and d:m:s units are normally
converted into degrees, and YYYY-MM-DD into julian days.
Similarly, some slight changes may have been introduced in the
units; the value given in the HTML files supersedes the value indicated in the ReadMe
file for this catalogue.
IX/29 ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000)
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ROSAT All-Sky Survey Faint source Catalogue (RASS-FSC)
Voges W., Aschenbach B., Boller Th., Brauninger H., Briel U., Burkert W.,
Dennerl K., Englhauser J., Gruber R., Haberl F., Hartner G., Hasinger G.,
Pfeffermann E., Pietsch W., Predehl P., Schmitt J., Trumper J.,
Zimmermann U.
<IAU Circ. 7432 (2000)>
=2000IAUC.7432R...1V
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ADC_Keywords: X-ray sources ; Surveys
Mission_Name: ROSAT
Description:
The ROSAT All-Sky Survey Faint Source Catalogue (RASS-FSC) is derived
from the all-sky survey performed during the ROSAT mission in the
energy band 0.1-2.4 keV. 105,924 sources are catalogued and represent
the faint extension to the RASS bright source catalogue (RASS-BSC,
1999A&A...349..389V, See Cat. IX/10). The sources have a detection
likelihood of at least 7 and contain at least 6 source photons. (The
likelihood of source detection is defined as L = -ln(1-P), with
P = probability of source detection).
For each source we provide the ROSAT name, the position in equatorial
coordinates, the positional error, the source countrate and error, the
background countrate, exposure time, date of observation,
hardness-ratios HR1 and HR2 and errors, extent and likelihood of
extent, and likelihood of detection.
Questions or comments may be directed to xray-info(at)mpe.mpg.de
File Summary:
FileName Lrecl Records Explanations
× 80 . This file
× ReadMe 80 . This file
× rass_fsc.dat 212 105924 The ROSAT All Sky Survey Faint Source Catalog
See also:
IX/10A : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)
http://www.xray.mpe.mpg.de/rosat/survey/rass-fsc/ : The ROSAT
All-Sky Survey Faint Source Catalogue Home Page
Byte-by-byte Description of file: rass_fsc.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [1RXS]
6- 21 A16 --- 1RXS ROSAT All-Sky Survey Catalogue source name (1)
24- 32 F9.5 deg RAdeg Right ascension (J2000), decimal degrees
34- 42 F9.5 deg DEdeg Declination (J2000), decimal degrees
44- 46 I3 arcsec PosErr ?=0 Total positional error
(including 6" systematic error)
48- 52 A5 --- ScrFlags [T.F] screening flags (2)
54- 57 A4 --- NewFlag [T._] 'new data' flags (3)
60- 68 E9.3 ct/s Count ?=0 Source countrate (4)
70- 78 E9.3 ct/s e_Count ?=0 Error on Count (4)
80- 88 E9.3 ct/s/arcmin2 bgCt ?=0 Background countrate (4)
90- 95 I6 s ExpTime ?=0 Exposure time
97-101 F5.2 --- HR1 [-1/1]? Hardness ratio 1 (5)
103-106 F4.2 --- e_HR1 ? Error on HR1 (6)
108-112 F5.2 --- HR2 [-1/1]? hardness ratio 2 (5)
114-117 F4.2 --- e_HR2 ? Error on HR2 (6)
119-123 I5 arcsec Extent Source extent, by which the source image
exceeds the point spread function.
125-128 I4 --- L_Extent ?=0 Likelihood of source extent (7)
130-133 I4 --- Ldetect ?=0 Likelihood of
source detection algorithm (7)
135-139 I5 arcsec ExtRad ?=0 Extraction radius
141-146 A6 --- PrioFlags [01] priority flags (8)
147 A1 --- PHA [ABCDb] PHA range of best detection (9)
149-152 F4.2 --- VigFactor ?=0 Vignetting factor
154-159 I6 "yyMMDD" IncDate [000518]?=0 Date when source was included (10)
161-166 I6 "yyMMDD" UpdDate [000000]?=0 Date when source properties
changed (11)
168-170 I3 --- Ncand Number of identification candidates in the
correlation catalogue
173-180 I8 --- SASS Identification number of SASS field (12)
181 A1 --- --- [_]
182-185 I4 --- MASOL SASS source number (MASOL number)
in SASS field (mainly for internal use)
187-189 I3 --- src Source number
191-192 I2 yr ObsBeg.Y Beginning of observation (year, offset 1900)
193-194 I2 "month" ObsBeg.M Beginning of observation (month)
195-199 F5.2 d ObsBeg.D Beginning of observation (day)
201-202 I2 yr ObsEnd.Y Beginning of observation (year, offset 1900)
203-204 I2 "month" ObsEnd.M Beginning of observation (month)
205-209 F5.2 d ObsEnd.D Beginning of observation (day)
211-212 I2 --- Rel [0,99] Reliability of Source
Note (1): The name is based on J2000 position (format JHHMMSS.S+DDMMSS).
This name is used in the generation of a link to a broad band
image if this image is available (see NewFlag, and Note (3))
Note (2): the flags are 'T' for 'true', 'F' or '_' for 'false'; '.' for not used
n (byte 48) nearby sources affecting SASS flux determination
p (byte 49) possible problem with position determination
e (byte 50) source extended beyond SASS extraction radius
d (byte 51) complex diffuse emission pattern
m (byte 52) source missed by SASS
Note (3): the flags are 'T' for 'true', 'F' or '_' for 'false'; '.' for not used
r (byte 54) source counts and extraction radius recalculated
i (byte 55) broad band image available (html link!)
v (byte 56) variability flag (not yet filled)
. (byte 57) dummy flag
Note (4): Countrates are vignetting corrected
Note (5): The hardness ratios are defined by:
hr1 = ( B - A ) / ( B + A ) , where
A = countrate in PHA range 11 - 41 (~ 0.1-0.4 keV)
B = countrate in PHA range 52 - 201 (~ 0.5-2.0 keV)
hr2 = ( D - C ) / ( D + C ) , where
C = countrate in PHA range 52 - 90 (~ 0.5-0.9 keV)
D = countrate in PHA range 91 - 201 (~ 0.9-2.0 keV)
(PHA = Pulse Height Amplitude)
Note (6): the true mean error is probably bigger, and
values larger than 9.99 are set to 9.99
Note (7): values larger than 9999 are set to 9999
Note (8): the flags indicate the sliding window detection history
using either the background map (M) or the local background (B),
and take the values 0 = no detection, 1 = detection;
The order of flags is:
M-broad, L-broad, M-hard, L-hard, M-soft, L-soft
Note (9): the PHA (Pulse Height Amplitude) range
PHA range with highest detection likelihood is indicated by
A = PHA range 11-41 (~ 0.1-0.4 keV)
B = PHA range 52-201 (~ 0.5-2.0 keV)
C = PHA range 52-90 (~ 0.5-0.9 keV)
D = PHA range 91-201 (~ 0.9-2.0 keV)
b or blank means 'broad'
Note (10): a value "000000" for the date indicates a removed source.
The "yy" part is for XXIst century
Note (11): a value "000000" indicates not-applicable date
The "yy" part is for XXIst century
Note (12): An overview of the field structure is available at URL
http://www.xray.mpe.mpg.de/rosat/survey/rass-bsc/sup/psplit.ps.gz
History:
* 11-Sep-2004: Reference (2000IAUC.7432R...1V) added (thanks to a
remark by H.J. Andernach)
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(End) Francois Ochsenbein [CDS] 26-May-2000