ACDS V10.0 - Detailed Description of IX/53

ACDS V10.0 - Sun Jan 19 08:03:51 CET 2025

| # Detailed Description of IX/53 : XMM-Newton slew survey Source Catalogue, version 2.0 (XMM-SSC, 2017) |

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/53       XMM-Newton slew survey Source Catalogue, version 2.0 (XMM-SSC, 2017)
    ================================================================================
    The XMM-Newton slew survey Source Catalogue, version 2.0
        XMM-SSC
        <XMM-SSC, Leicester, UK (2017)>
       =2018yCat.9053....0X
    ================================================================================
    ADC_Keywords: X-ray sources; Surveys

    Mission_Name: XMM

    Keywords: catalogs - astronomical data bases - surveys - X-rays: general

    Description:
        XMMSL2 is the second catalogue of X-ray sources found in slew data
        taken from the European Space Agency's (ESA) XMM-Newton observatory,
        and has been constructed by members of the XMM SOC and the EPIC
        consortium on behalf of ESA. This release uses results of work which
        has been carried out within the framework of the EXTraS project
        ("Exploring the X-ray variable and Transient Sky"), funded from the
        EU's Seventh Framework Programme under grant agreement no.607452.

        This is the first release of XMMSL2 which contains data taken between
        revolutions 314 and 2758. The previous catalogue was called
        XMMSL1_Delta6 and contained slews up to revolution 2441.

        The release includes two FITS files. A full catalogue
        (xmmsl2_total.fits.gz), containing 72352 detections found with a
        likelihood of DET_ML>8 and a "clean" catalogue (xmmsl2_clean.fits.gz)
        where all known bad sources have been removed and where the detection
        limit has been raised to DET_ML>10.5 in general and DET_ML>15.5 for
        sources found in images with a higher than usual background. Efforts
        have been made to identify spurious detections and 3017 have been
        flagged as such in the full catalogue.

    File Summary:

           FileName      Lrecl  Records   Explanations

    ×                   80        .   This file
    × ReadMe            80        .   This file
    × xmmsl2c.dat     1219    29393   XMM-Newton slew survey Source Catalogue: XMMSL2
                                     "clean version" (Release 2.0, 14th March 2017)
    × xmmsl2c.fits    2880     9746   Clean XMMSL2 catalog in fits
    × xmmsl2t.fits    2880    23976   Full XMMSL2 catalog (72352 detections)

    See also:
     IX/50  : XMM-Newton Serendipitous Source Catalogue 3XMM-DR6 (XMM-SSC, 2016)
     II/340 : XMM-OM Serendipitous Source Survey Catalogue XMM-SUSS2.1 (Page+ 2016)

     https://www.cosmos.esa.int/web/xmm-newton/xmmsl2-ug : XMMSL2 Home Page

    Byte-by-byte Description of file:  xmmsl2c.dat

       Bytes Format Units       Label     Explanations

       1- 23  A23   ---         XMMSL2    Official name for sources detected in
                                             the XMM-Newton slew survey
                                             (UNIQUE_SRCNAME) (1)
      25- 34  A10   ---         ObsId     Observation number (OBSID) (2)
      36- 38  I3    ---         SNum      Number which uniquely identifies each
                                             detection in an observation (SOURCENUM)
      40- 48  F9.5  deg         RAdeg     Right ascension (J2000) (RA) (3)
      50- 58  F9.5  deg         DEdeg     Declination (J2000) (DEC) (3)
      60- 65  F6.2  arcsec      ePos      Statistical error on the source position
                                             (RADEC_ERR) (4)
      67- 75  F9.5  deg         GLON      Galactic longitude (LII)
      77- 85  F9.5  deg         GLAT      Galactic latitude (BII)
      87- 95  F9.6  ---         HR1       ? Hardness ratio (HR1) (5)
      97-104  F8.6  ---         e_HR1     ? rms uncertainty on HR1 (HR1_ERR) (6)
     106-124  A19   ---         DateS     Start time of the slew containing
                                             this source (DATE_OBS)
     126-144  A19   ---         DateE     End time of the slew containing
                                             this source (DATE_END)
     146-157  E12.6 ct          SctsB8    ? Number of background subtracted counts,
                                            in the total energy band (0.2-12keV)
                                            (SCTS_B8) (7)
     159-167  F9.5  ct          e_SctsB8  ? Statistical 1 sigma error on SctsB8
                                            (SCTSB8ERR)
     169-180  E12.6 ct          SctsB7    ? Number of background subtracted counts,
                                            in the hard energy band (2-12keV),
                                            corrected for the PSF (SCTS_B7)
     182-189  F8.5  ct          e_SctsB7  ? Statistical 1 sigma error on SctsB7
                                            (SCTSB7ERR)
     191-202  E12.6 ct          SctsB6    ? Number of background subtracted counts,
                                            in the soft energy band (0.2-2keV),
                                            corrected for the PSF (SCTS_B6)
     204-211  F8.5  ct          e_SctsB6  ? Statistical 1 sigma error on SctsB6
                                            (SCTSB6ERR)
     213-224  E12.6 pix         XimaB8    ? X position in the total band image in
                                            image pixels (XIMAB8)
     226-237  E12.6 pix         YimaB8    ? Y position in the total band image in
                                            image pixels (YIMAB8)
     239-250  E12.6 pix         XimaB7    ? X position in the hard band image in
                                            image pixels(XIMAB7)
     252-263  E12.6 pix         YimaB7    ? Y position in the hard band image in
                                            image pixels(YIMAB7)
     265-276  E12.6 pix         XimaB6    ? X position in the soft band image in
                                            image pixels(XIMAB6)
     278-289  E12.6 pix         YimaB6    ? Y position in the soft band image in
                                            image pixels(YIMAB6)
     291-299  F9.6  pix         ExtB8     ? Spatial extension of the source in the
                                            total energy band (EXT_B8) (7)
     301-309  F9.6  pix         e_ExtB8   ? Statistical one sigma error on ExtB8
                                            (EXTB8ERR)
     311-319  F9.6  pix         ExtB7     ? Spatial extension of the source in the
                                            hard energy band (EXT_B7) (7)
     321-329  F9.6  pix         e_ExtB7   ? Statistical one sigma error on ExtB7
                                            (EXTB7ERR)
     331-339  F9.6  pix         ExtB6     ? Spatial extension of the source in
                                            the soft energy band (EXT_B6) (7)
     341-349  F9.6  pix         e_ExtB6   ? Statistical one sigma error on ExtB6
                                            (EXTB6ERR)
     351-362  F12.6 ---         DetMLB8   ? Detection likelihood in the total
                                            (0.2-12keV) energy band (DETMLB8)
     364-375  F12.6 ---         DetMLB7   ? Detection likelihood in the hard
                                            (2-12keV) energy band (DETMLB7)
     377-388  F12.6 ---         DetMLB6   ? Detection likelihood in the soft
                                            (0.2-2keV) energy band (DETMLB6)
     390-400  F11.6 ---         ExtMLB8   ? Likelihood of the source being extended
                                            in the total band (EXTMLB8)
     402-412  F11.6 ---         ExtMLB7   ? Likelihood of the source being extended
                                            in the hard band (EXTMLB7)
     414-424  F11.6 ---         ExtMLB6   ? Likelihood of the source being extended
                                            in the soft band (EXTMLB6)
     426-433  F8.6  ct/pix      BgMapB8   ? Background value for the total band
                                            (BGMAPB8)
     435-442  F8.6  ct/pix      BgMapB7   ? Background value for the hard band
                                            (BGMAPB7)
     444-451  F8.6  ct/pix      BgMapB6   ? Background value for the soft band
                                            (BGMAPB6)
     453-461  F9.6  s           ExpMapB8  ? Effective on-axis exposure time in the
                                            total energy band (EXPMAPB8)
     463-471  F9.6  s           ExpMapB7  ? Effective on-axis exposure time in the
                                            hard energy band (EXPMAPB7)
     473-481  F9.6  s           ExpMapB6  ? Effective on-axis exposure time in the
                                            soft energy band (EXPMAPB6)
     483-494  F12.6 10-15W/m2   FluxB8    ? Flux in the total energy (0.2-12keV)
                                            band (FLUX_B8)
     496-505  F10.6 10-15W/m2   e_FluxB8  ? Error in FluxB8 (FLUXB8ERR)
     507-518  F12.6 10-15W/m2   FluxB7    ? Flux in the total energy (2-12keV)
                                            band (FLUX_B7)
     520-529  F10.6 10-15W/m2   e_FluxB7  ? Error in FluxB7 (FLUXB7ERR)
     531-540  F10.6 10-15W/m2   FluxB6    ? Flux in the total energy (0.2-2keV)
                                            band (FLUX_B6)
     542-551  F10.6 10-15W/m2   e_FluxB6  ? Error in FluxB6 (FLUXB6ERR)
     553-564  F12.6 ct/s        RateB8    ? Total band count rate (RATE_B8)
     566-574  F9.6  ct/s        e_RateB8  ? Error in RateB8 (RATEB8ERR)
     576-585  F10.6 ct/s        RateB7    ? Hard band count rate (RATE_B7)
     587-596  F10.6 ct/s        e_RateB7  ? Error in RateB7 (RATEB7ERR)
     598-607  F10.6 ct/s        RateB6    ? Soft band count rate (RATE_B6)
     609-617  F9.6  ct/s        e_RateB6  ? Error in RateB6 (RATEB6ERR)
     619-627  F9.5  deg         RAdegB8   ? Total band right ascension (J2000)
                                            (RA_B8)
     629-637  F9.5  deg         DEdegB8   ? Total band declination (J2000) (DEC_B8)
     639-647  F9.5  deg         ePosB8    ? Statistical error on total band
                                            position (RADECB8ERR)
     649-657  F9.5  deg         GLONB8    ? Total band galactic longitude (LII_B8)
     659-667  F9.5  deg         GLATB8    ? Total band galactic latitude (BII_B8)
     669-677  F9.5  deg         RAdegB7   ? Hard band right ascension (J2000)
                                            (RA_B7)
     679-687  F9.5  deg         DEdegB7   ? Hard band declination (J2000) (DEC_B7)
     689-697  F9.5  deg         ePosB7    ? Statistical error on hard band position
                                            (RADECB7ERR)
     699-707  F9.5  deg         GLONB7    ? Hard band galactic longitude (LII_B7)
     709-717  F9.5  deg         GLATB7    ? Hard band galactic latitude (BII_B7)
     719-727  F9.5  deg         RAdegB6   ? Soft band right ascension (J2000)
                                            (RA_B6)
     729-737  F9.5  deg         DEdegB6   ? Soft band declination (J2000) (DEC_B6)
     739-747  F9.5  deg         ePosB6    ? Statistical error on soft band position
                                            (RADECB6ERR)
     749-757  F9.5  deg         GLONB6    ? Soft band galactic longitude (LII_B6)
     759-767  F9.5  deg         GLATB6    ? Soft band galactic latitude (BII_B6)
     769-780  A12   ---         Flag      [CLEAN_SAMPLE] Flag for source included
                                            in the clean subset (VAL_FLAG) (8)
     782-818  A37   ---         SnameB8   Source name defined in the total band
                                            list (SRCNAME_B8) (9)
     820-856  A37   ---         SnameB7   Source name defined in the hard band list
                                            (SRCNAME_B7) (9)
     858-894  A37   ---         SnameB6   Source name defined in the soft band list
                                            (SRCNAME_B6) (9)
     896-926  A31   ---         XInameB8  Name of the image containing the total
                                            band detection (XIMNAME_B8)
     928-958  A31   ---         XInameB7  Name of the image containing the hard
                                            band detection (XIMNAME_B7)
     960-990  A31   ---         XInameB6  Name of the image containing the soft
                                            band detection (XIMNAME_B6)
         992  I1    ---         Inext     [0/1] Extended source flag
                                            (VER_INEXT) (10)
         994  I1    ---         Halo      [0/1] Halo flag (VER_HALO) (11)
         996  I1    ---         HIbgnd    [0/1] Bright region flag
                                            (VER_HIBGND) (12)
         998  I1    ---         Nredg     [0] Not used in XMMSL2 (VER_NREDG)
        1000  I1    ---         Psusp     [0/1] Inaccurate position flag
                                            (VER_PSUSP) (13)
        1002  I1    ---         False     [0/1] Catch-all for problems not included
                                            in the other flags (VER_FALSE) (14)
     1004-1041  A38   ---         Com       Suspect attitude reconstruction in RAF
                                            (FLAG_COMMENT) (15)
     1043-1077  A35   ---         Ident     Cross-correlations of the positions of
                                            the slew sources (IDENT) (16)
     1081-1096  A16   ---         1RXS      Name of the closest Rosat All Sky Survey
                                            (RASS) source (RASSNAME) (17)
     1098-1116  A19   ---         Type      Source type (ID_CATEGORY) (18)
     1118-1125  A8    ---         r_Type    Reference for Type (ID_RESOURCE) (19)
     1127-1136  F10.6 arcsec      DistC     ? Distance between the best match
                                            candidate and the slew survey source
                                            (ID_DIST)
     1138-1143  F6.3  arcsec      DistR     ? Distance from the best match ROSAT
                                            source and the slew source (RASS_DIST)
     1145-1147  A3    ---         ModeID    Observing mode of the EPIC-pn camera
                                            (MODE_ID) (20)
     1149-1153  F5.1  ct/s        ImBGRate  Peak background count rate in the image
                                            from which the source was extracted
                                            (IMAGEBGRATE) (21)
     1155-1164  F10.4 d           MJDStart  Start time of the subimage where the
                                            source is located in modified Julian
                                            date (MJD_START)
     1166-1175  F10.4 d           MJDStop   End time of the subimage where the source
                                            is located in modified Julian date
                                            (MJD_STOP)
        1177  I1    ---         OPTLOAD   [0/1] Warning flag indicating that the
                                            source may suffer from optical loading
                                            (VER_OPTLOAD)
     1179-1182  I4    ---         FiltCt    Number of counts found within a
                                            1 arcminute radius about the source
                                            position after standard filtering is
                                            applied  (FILT_CNTS)
     1184-1187  I4    ---         UnfiltCt  Number of counts found within a
                                            1 arcminute radius about the source
                                            position with no filtering applied
                                            (UNFILT_CNTS)
     1189-1211  A23   ---         USXMMSL1  Name of the same source in the previous
                                            XMMSL1 catalogue if existing (US_XMMSL1)
     1213-1219  I7    ---         USExtras  Corresponding SRCID value within the
                                             EXTraS LTV catalogue (US_EXTRAS) (22)

    Note (1): This is the official name for sources detected in the XMM-Newton slew
     survey. It starts with the prefix, XMMSL2 (evolving from XMMSL1, the IAU
      registered designator), and then encodes the J2000 sky position, e.g.
      XMMSL2 J010537.6+364858. The name is assigned in two passes. When the three
      independent energy band source lists are combined to form one catalogue the
      source name is set using the position in the band where the DET_ML likelihood
      is the highest. A second pass is then performed such that sources which have
      been observed in more than one slew are given the same name. Again, priority
      is given depending on the detection likelihood. Note that the combination of
      UNIQUE_SRCNAME and observation number (OBSID) is unique. Detections are
      deemed to be from the same source if their centres lie within 30 arcseconds
      of each other. Note that the statistical position error (RADEC_ERR) calculated
      by the source search software is not used in this calculation. This is
      because the systematic error on the slew attitude reconstruction dominates the
      error budget in many cases. Given the scarcity of slew sources on the sky,
      30" was found to be a reasonably robust match radius for point sources.
      It is not so good for extended sources and the catalogue may contain multiple
      detections of the same extended source with different names.
    Note (2): This is the observation number assigned to the slew by the satellite
      scheduling system. Slew observations always begin with a 9 to distinguish
      them from pointed observations, followed by a 4 digit satellite orbit number
      and a 5 digit slew designator, e.g. 9031400004, refers to the second slew of
      revolution 314.
    Note (3): In the event of a detection in more than one energy band, the
      coordinates are taken from the band with the highest detection likelihood.
    Note (4): Statistical error on the source position as returned by the source
      detection software.
    Note (5): The hardness ratio, defined as
       HR1 = (rateb7-rateb6)/(rateb7+rateb6)
       where rate_b7 is the hard band count rate and rate_b6 is the soft band count
       rate. This has been calculated for the 1936 sources which have a positive
       detection in both bands.
    Note (6): Error on the hardness ratio calculated as:
       sqrt(rateb7err*rateb7err + rateb6err*rateb6err) /(rateb7+rateb6)
       where rateb7err and rateb6err are the errors on the hard and soft band
       count rates respectively.
    Note (7): This measures the deviation from a point source of the spatial
       distribution of the source counts. It is defined as the sigma of a Gaussian
       which would need to be convolved with the point spread function (PSF) to
       produce the observed counts distribution. The software (emldetect) fits
       sources out to a maximum extent of 20 pixels.
       Units: 4.1"x4.1" image pixels
    Note (8): A text string which is set to 'CLEAN_SAMPLE' if this source is
       included in the clean subset.
    Note (9): The format is 'xs' followed by the revolution number, the observation
      ID and the source position, e.g. xs0841908410000212:57:07.5+01:50:42
    Note (10): If set true (1), this flag notes that a detection has been found with
      in an extended source and is probably false. This flag is used to ensure that
      only one source is quoted for the large supernova remnants.
    Note (11): If set true (1), this flag indicates that a detection lies within the
      point spread function, or halo, of a very bright source and is probably
      spurious.
    Note (12): If set true (1), this flag indicates that the source lies within a
      bright region, caused by high background, and is probably spurious.
    Note (13): This flag indicates that the quoted position of the source is likely
      to be inaccurate. In a few slews the attitude reconstruction is poor and in
      these cases the actual position of the source is difficult to determine and
      can be wrong by an arcminute.
    Note (14): This is a catch-all for problems not included in the other flags. In
      the catalogue 99 detections have this flag set true. Reasons include: the
      exposure time has been calculated as zero, a detection due to a very bright
      source, e.g. SCO X-1, out of the field of view, a possible cosmic ray or a
      very bad attitude reconstruction.
    Note (15): A comment which explains why a particular source flag has been set
      to true
    Note (16): Cross-correlations of the positions of the slew sources with
      astronomical databases and catalogues have been performed (see section on
      IDs). This column gives the catalogue name of the best match.
    Note (17):  Voges et al. (1999, Cat. IX/10) and Voges et al. (2000, Cat. IX/29).

    Note (18): The source type as returned by SIMBAD, NED and the other resources
      used in the cross-matching process. This is directly taken from the catalogue
      in question and no attempt has been made to rationalise the values.
    Note (19): The astronomical database or catalogue from which the best match has
      been selected. e.g. SIMBAD, NED, etc.
    Note (20): Observing mode of the EPIC-pn camera as follows:
      FF= Full frame mode
      eFF = extended full frame mode
      LW = large window mode
    Note (21): Peak background count rate in the image from which the source was
      extracted. This is measured as the count rate, over the whole image, for
      events with energy >10keV (PI>10000). It is quoted to a resolution of 0.1ct/s
      and is used to determine the overall background environment in which a source
      was detected. This value is used in the creation of a clean subsample of the
      catalogue (see top level description). Generally, the higher this value, the
      greater the probability that the source is spurious. This is especially true
      if the detection likelihood of the source is less than 15.5. The value has
      been tabulated for images with a background rate greater than 2ct/s. For
      quieter images the value has been artifically set to 1.9 ct/s.
    Note (22): This release of XMMSL2 makes use of work carried out within the
      framework of the EXTraS project. XMMSL2 is closely linked to the long-term
      variability (LTV) catalogue within EXTraS, and this US_EXTRAS column provides
      the corresponding SRCID value within the EXTraS LTV catalogue.

    History:
        Copied at https://www.cosmos.esa.int/web/xmm-newton/xmmsl2-ug
    ================================================================================
    (End)                                      Patricia Vannier [CDS]    09-Jan-2018