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IX/12               The WGACAT version of ROSAT sources   (White+ 1995)

The WGACAT version of the ROSAT PSPC Catalogue, Rev. 1 White N.E., Giommi P., Angelini L. <HEASARC, Code 660, LHEA/GSFC, Greenbelt (1995)>
ADC_Keywords: X-ray sources Mission_Name: ROSAT Description: WGACAT is a catalogue of point sources generated at HEASARC from all the ROSAT PSPC (Position Sensitive Proportional Counter) pointing observations from Feb 1991 to March 1994. These were the files available in the public archive at HEASARC as of September 1994. This catalog is an independent research effort aimed at releasing as quickly as possible a list of sources detected by ROSAT in its pointed phase to: (1) identify the detected sources, (2) ensure their timely observation by currently active X-ray missions e.g. ASCA, (3) to search for objects which show exceptional time variability and spectral properties and (4) to provide an independent check of the detection technique used in the official ROSAT project (SAS) processing. WGACAT stands for N.E. White (HEASARC/GSFC). P. Giommi (ESA), and L. Angelini (HEASARC/GSFC) File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file wgacat.dat 790 68907 The catalogue
See also: IX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1996) IX/11 : ROSAT Source Catalogue (1RXP), Version 1995-05-11 IX/28 : ROSAT HRI Pointed Observations (1RXH) (ROSAT Team, 1999) J/A+AS/114/465 : ROSAT XUV Pointed Phase Source Catalogue (Kreysing+ 1995) J/MNRAS/274/1165 : The 2RE Source Catalogue (Pye+ 1995) http://ledas-www.star.le.ac.uk/arnie/dbhlp_WGACAT.html : The WGA Catalog of ROSAT Point Sources Help. Byte-by-byte Description of file: wgacat.dat
Bytes Format Units Label Explanations
2- 13 A12 --- 1WGA Name from this catalogue 15- 22 F8.4 deg RAdeg Right ascension of source (J2000) 24- 31 F8.4 deg DEdeg Declination of source (J2000) 33- 39 F7.1 pix Xpos The source coordinate in original pixels 41- 47 F7.1 pix Ypos The source coordinate in original pixels 49- 54 F6.2 deg GLON Galactic Longitude 56- 61 F6.2 deg GLAT Galactic Latitude 63- 71 E9.2 ct/s Count Background subtracted count rate accumulated in PHA bins 24 to 224 (0.24-2.0keV) 73- 80 E8.1 ct/s e_Count Mean error on Count 82- 92 E11.4 mW/m2 Fx X-ray flux using a constant correction factor of 1.5x10-11 mW/m2 (erg/s/cm2). 94- 97 F4.2 --- VigFactor Telescope vignetting correction (1) 99-100 I2 arcsec ErrorRad 90% confidence source error radius. 102-105 I4 arcsec BoxSize Optimum source box size. 107-114 F8.4 deg RAc.deg Image center right ascension. (2) 116-123 F8.4 deg DEc.deg Image center declination. (2) 125-130 F6.3 arcmin offset1 Offset of detected position from (RAc,DEc) 132-139 F8.4 deg RAt.deg Target right ascension (3) 141-148 F8.4 deg DEt.deg Target declination (3) 150-155 F6.3 arcmin offset2 Offset of detected position from (RAt,DEt) 157-172 A16 --- OBJECT Original field name as found in event list 174-179 I6 --- ROR [100000/901000] number of unique sequences 181-186 A6 "YY.DDD" StartDay Starting day of observation ("DDD" in 001-366 range) 188-193 A6 "YY.DDD" EndDay Ending day of observation 195-196 I2 --- Ndetect Total number of detections in the image. 198-199 I2 --- IDno The source number in the field (4) 201-215 A15 --- ImageFile FITS image file name 217-227 A11 --- EventFile Event file name 229-246 A18 --- SourceID Unique source identification (5) 248-257 E10.3 --- PrBkg Probability that the detection is a background fluctuation 259-264 F6.2 --- SNR The signal to noise ratio of the source 266-267 I2 --- Qual [1/10] Quality flag from bad to good (6) 269 A1 --- Region [I/O] Region of the ROSAT image (I=in, O=out) 271-272 I2 --- Zoom Rebinning factor of the image 274-284 E11.4 ct/pix/s Bgnd Background count rate 286-291 I6 s ExpTime Exposure time of the field 293-300 F8.4 --- SR1 Softness ratio 11-39/40-85 (7) 302-309 F8.4 --- e_SR1 Mean error on SR1 311-318 F8.4 --- HR1 Hardness ratio 86-200/40-85 (7) 320-327 F8.4 --- e_HR1 Mean error on HR1 329-336 F8.4 --- SR2 Hard softness ratio 50-86/87-129 (7) 338-345 F8.4 --- e_SR2 Mean error on SR2 347-354 F8.4 --- HR2 Hard hardness ratio 130-240/87-129 (7) 356-363 F8.4 --- e_HR2 Mean error on HR2 365-371 I7 ct Counts Total number of counts detected 373-379 F7.2 ct e_Counts Mean error on Counts 381-387 I7 ct Count1 Low band (11-39=0.1-0.4keV) counts 389-395 F7.2 ct e_Count1 Mean error on Count1 397-403 I7 ct Count2 Mid band (40-85=0.4-0.9keV) counts 405-411 F7.2 ct e_Count2 Mean error on Count2 413-419 I7 ct Count3 High band (86-200=0.92.0keV) counts 421-427 F7.2 ct e_Count3 Mean error on Count3 429-436 F8.3 --- Chi2 Variability test (8) 438 I1 --- XidFlag [1]? 1 if id with pre-Rosat X-ray source 440-453 A14 --- Xid1 First name of X-ray identifier 455-468 A14 --- Xid2 2nd name of X-ray identifier 470-483 A14 --- Xid3 3rd name of X-ray identifier 485-495 E11.4 ct/s IPCcount ? Count rate detected by the Einstein IPC. 497-507 E11.4 ct/s e_IPCcount ? Mean error on IPCcount 509-519 E11.4 --- IPC/PSPC ? Ratio of IPC/PSPC count rates. 521-531 E11.4 --- e_IPC/PSPC ? Mean error on IPC/PSPC 533 I1 --- OIdFlag [1]? 1 if ID with optical source 535-548 A14 --- OId1 First name of optical counterpart 550-563 A14 --- OId2 2nd name of optical counterpart 565-578 A14 --- OId3 3rd name of optical counterpart 580-593 A14 --- OId4 4th name of optical counterpart 595-608 A14 --- SIMBAD Name in SIMBAD data-base (if existing) 610-614 F5.2 mag Vmag ? V magnitude of any optical counterpart 616-626 E11.4 --- Fx/Fo ? X-ray over optical flux ratio 628-637 E10.3 --- AoX ? Optical to X-ray slope 639-644 F6.4 --- z ? Redshift of counterpart 646-657 A12 --- Class Source classification 659 I1 --- RIdFlag [1]? 1 if ID with radio source 661-674 A14 --- RId1 First name of radio source 676-689 A14 --- RId2 First name of radio source 691-702 A12 --- IRAS Name in IRAS (II/125 or II/156) 704-706 A3 --- IdCat [HIC ] Catalog used for optical position (9) 708-715 F8.3 arcmin IDoffset ? Offset of Id star from ROSAT position 717-724 F8.3 arcmin oRA ? Offset from reference star (9) 726-733 F8.3 arcmin oDE ? Offset from reference star (9) 735 I1 --- WGAversion [1]? Version of WGACAT 737-750 A14 --- MPEname Name in MPE catalog IX/11 752 I1 --- MPEflag [1,3]? Comparison with MPE <IX/11> (10) 754-763 E10.3 ct/s MPEcount ? Count from MPE 765-774 E10.3 ct/s e_MPEcount ? Mean error on MPEcount 776-784 E9.2 cm-2 NH21cm ? 21cm number of H from Starke et al. 786-790 F5.2 mag B-V ? B-V colour
Note (1): the vignetting factor increases from 1 for sources detected on the axis to higher values when the source was detected off-axis. Note (2): the image center corresponds roughly to the pointing position. Note (3): the target position are the coordinates of the primary target in the field which can be different from (RAc, DEc) Note (4): the source number increases outwards from the center of the image. Note that this number is unique only with the processed region (eg. inner or outer). In the same field two sources can have the same IDno but the parameter Region will be 'I' and 'O'. Note (5): the unique source ID is composed by xxnnnnnnnregionidno, where xx is either 'RP' for US sequence and 'WP' for German/UK sequence, nnnnnnnn is the ROR number, region is either 'O' for source detected in the outer region or 'I' for source detected in the inner region, idno is the source number detected in the field. Note this ID is unique only within a given revision. Note (6): Detailed meaning of the Qflag: 9 or 10 indicates a secure detection of a point source, which has been confirmed by visual inspection of each source (using the thumb nail GIFs available through BROWSE). 8 indicates that the entire field has been inspected, and there was no obvious problem with the detections in the field as a whole, and that it is reasonably secure. This is different from Qflag 9 or 10 because each source has not been individually identified. 5-7 indicates that there is something suspicious in the field. This might simply mean that there is a bright source, which makes the contrast on the image such that it is hard to see the fainter sources. But it may also indicate a cluster of detections suggesting extended emission. These fields should be double checked by eye to ensure the detection is real. It is suggested in this case to inspect the corresponding intensity map. 4 indicates that many (typically more than half) the detections are caused by extended emission, but that there are still good sources (typically a small fraction over the total number of detection). 3 indicates a source that looks perfectly good, is really bad. This may result from a local arc in the detector caused by a temporary HV breakdown or by a mystery pointing that interrupts the sequence. 2 was assigned to all fields taken in the first 2 months of the mission (before the six month survey phase began) where the processing and satellite were not stable. Probably most of the detection found in those field are correct, but it require either a checking of the housekeeping parameters or that the processing to create the final event list was correct. 1 indicates most if not all of the detections in that field are spurious, because of a large extended object. 0 means the field has not been quality checked. For an ultra clean source use Qflag≥5. Note (7): the ratios are defined by (PHA bins) (keV ranges) SR1 11-39/40-85 0.1-0.4/0.4-0.9 HR1 86-200/40-85 0.9-2.0/0.4-0.9 SR2 50-86/87-129 0.5-0.9/0.9-1.3 HR2 130-240/87-129 1.3-2.4/0.9-1.3 Note (8): the The Chi2 value is obtained in comparing the time arrival distribution of the photons collected in each detection box with the corresponding distribution of the entire image using a Kolmogorov-Smirnov (KS) test. The result of the KS test is a chi2 value with 2 d.o.f. A value >100 is really variable. Note (9): Only HIC (Hipparcos Input Catalog, Turon et al. I/196) Note (10): This flag contains the following values: 1: source within 20 arcsec in inner region 2: source within 60 arcsec in outer region 3: this field is included in the ROSATSRC catalog, but the source is not detected.
History: The file was created from the "large_wgacat.txt" file copied at copied at ftp://legacy.gsfc.nasa.gov/rosat/wgacat/files/rev1; the file was dated April 9, 1995. Most of the non-empty fields of the large_wgacat.txt have been kept to generate the "wgacat.dat" file; noticeable exceptions are the columns extracted from GSC, from IRAS and from radio catalogues. Contact persons: Any questions about, or problems with, the WGA catalogue should be addressed to Nick White, Paolo Giommi and Lorella Angelini at References: Giommi, P. et al. 1991, Ap.J., 378, 77 Giommi, P., Angelini, L., Jacobs P., Tagliaferri, G., 1991, in "Astronomical Data Analysis Software and Systems I" , D.M.Worrall, C. Biemesderfer and J. Barnes eds, 1991, A.S.P. Conf. Ser. 25, 100 Giommi, P., White, N.E. and Angelini, L., 1994, in "Astronomical Data Analysis Software and Systems VI", in press. Giommi, P. et al. 1995, in preparation. Maccacaro, T., et al. 1988, Ap.J., 326, 680. Pallavicini, R., et al. 1981, Ap.J., 248, 279. Stark, et al. private communication
(End) Francois Ochsenbein [CDS] 22-Oct-1996
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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