Astronomical Data Center

ADCADC/CDS Standard Document for Catalog:
/catalogs/9/9022/

The following is the "ReadMe" document that describes this ADC catalog. You can access the files described here in three ways:

1. Use the ADC Data Viewer Suite to visualize the data. [preview
2. Get the data files via anonymous FTP. (See Note.) [ftp


IX/22               Einstein extended deep survey         (Primini+, 1991)
================================================================================
The CfA Eisntein observatory extended deep X-ray survey
    Primini F.A., Murray S.S., Huchra J., Schild R., Burg R., Giacconi R.
   <Astrophys. J. 374, 440 (1991)>
   =1991ApJ...374..440P
================================================================================
ADC_Keywords: QSOs ; X-ray sources
Mission_Name: Einstein
Keywords: quasars - X-ray: sources

Description:

    The Einstein  Deep Survey program  (EDS)  consists of  very deep X-ray
    exposures in  selected regions of  the sky at  high galactic latitude.
    The  main purposes of the survey are  to investigate the nature of the
    extragalactic X-ray background  through direct  source counts  at very
    low flux levels and to study  the  nature  of  the  very  faint  X-ray
    sources which comprise a significant fraction, if not all, of the soft
    X-ray background.

    The survey includes 9 IPC observations and 34 HRI observations, which,
    in general,  cover the central 32'x32'  regions of the IPC fields.  In
    total,  178 IPC sources  and  202  HRI  sources  were  detected  above
    thresholds set to allow ~1 false source per observation.

    Data  from all IPC energy bands and all HRI detect cells are included.
    The  data are largely the result of  standard Einstein Rev.  1 HRI and
    Rev.  1B  IPC reprocessing;  however,  minor  corrections to IPC count
    rates,   fluxes,  and flux significances have been made to account for
    different  column densities toward various fields and small systematic
    errors in  the IPC analysis of count  rates and significances for long
    exposures.  For  further details please refer  to the paper referenced
    above.

    The HRI field parameters have been determined from standard processing
    and from other information  contained  in  the  HRI  .SDF  file.   For
    information on HRI sources, see the table "hsrc.dat";  for information
    on individual IPC fields, see the table "ifield.dat".

File Summary:
--------------------------------------------------------------------------------
 FileName    Lrecl Records  Explanations
--------------------------------------------------------------------------------
ReadMe         80        .  This file
targets.dat    40       43  EDS Target Information
hfield.dat    110       34  EDS Field Parameters for HRI Observations
hfluxes.dat   332      210  EDS Secondary HRI Source Parameters
hsrc.dat      174      210  EDS HRI Source Positions and Count Rates
hris_sep.dat   80      380  EDS Separations Between HRI Srcs in a Single Field
ifield.dat    153        9  EDS IPC Field Parameters
isrc.dat      271      178  EDS IPC Source Parameters
ispec.dat     375      178  EDS Spectral Parameters for IPC Sources
icomp.dat      98      453  EDS IPC Source Component Parameters
ipchri.dat     89     5861  EDS Separations Between IPC and HRI Sources
ihsample.dat   15       45  EDS Cross-Reference of HRI and IPC Sources
sample.dat    136       45  EDS IPC, HRI + Optical Data for 4.5Sigma IPC Sample
optinfo.dat    45       25  EDS Optical Data for Srcs in the 4.5 Sigma Sample
--------------------------------------------------------------------------------

See also:
     IX/23 : Einstein Observatory Source Catalog
     IX/24 : The Einstein Observatory High Resolution Imager Source List
     IX/25 : Einstein Observatory Imaging Proportional Counter (IPC) Parameters
     IX/26 : Einstein Observatory, Revision 1B. Processings
     IX/27 : Einstein Observatory Catalog (OCAT or Yellow Book)


Byte-by-byte Description of file: targets.dat
--------------------------------------------------------------------------------
 Bytes Format Units  Label    Explanations
--------------------------------------------------------------------------------
  2- 6 I5    ---     Seqno    Sequence number (G1)
  8-10 A3    ---     detector Detector (IPC or HRI)
 12-13 I2    h       RAh      Right Ascension (B1950) (hour)
 15-16 I2    min     RAm      Right Ascension (B1950) (min)
 18-19 I2    s       RAs      Right Ascension (B1950) (sec)
    21 A1    ---     DE-      Declination sign (B1950)
 22-23 I2    deg     DEd      Declination (B1950) (deg)
 25-26 I2    arcmin  DEm      Declination (B1950) (arcmin)
 28-29 I2    arcsec  DEs      Declination (B1950) (arcsec)
 31-40 F10.3 s       exptime  Exposure time (2)
--------------------------------------------------------------------------------
Note (2):  This column gives the net time,  in seconds,  for the processed
    image (uncorrected for deadtime effects).
--------------------------------------------------------------------------------

Byte-by-byte Description of file: hfield.dat
--------------------------------------------------------------------------------
 Bytes  Format Units  Label  Explanations
--------------------------------------------------------------------------------
   2-  6 I5    ---    Hseqno HRI Sequence Number  (G1)
   8- 17 F10.3 s      ontime Exposure Time
  19- 24 F6.3  ct     globk  Background in 12"x12" detect cell (in 9' circle)
  26- 31 F6.3  ct     detbk  Background in 12"x12" detect cell (in 5' circle)
  33- 39 F7.3  ct     th12   Threshold counts for source detection (12"x12"
                              cell)
  41- 47 F7.3  ct     th24   Threshold counts in 24"x24" cell
  49- 55 F7.3  ct     th36   Threshold counts in 36"x36" cell
  57- 64 F8.3  ct     th48   Threshold counts in 48"x48" cell
  66- 73 F8.3  ct     th72   Threshold counts in 72"x72" cell
  75- 82 F8.3  ct     th120  Threshold counts in 120"x120" cell
  84- 85 I2    h      RAh    Right Ascension (B1950) (hour) (1)
  87- 88 I2    min    RAm    Right Ascension (B1950) (min)
  90- 91 I2    s      RAs    Right Ascension (B1950) (sec)
      93 A1    ---    DE-    Declination sign (B1950)
  94- 95 I2    deg    DEd    Declination (B1950) (deg)
  97- 98 I2    arcmin DEm    Declination (B1950) (arcmin)
 100-101 I2    arcsec DEs    Declination (B1950) (arcsec)
 103-110 F8.3  deg    nroll  Nominal Roll Angle (G2)
--------------------------------------------------------------------------------
Note (1): These columns give the nominal right ascension and declination
    (B1950) of the field.  The nominal position is the center of the image
    which  differs slightly from  the center of  the field of  view due to
    aspect and boresight offsets.
--------------------------------------------------------------------------------

Byte-by-byte Description of file: hfluxes.dat
--------------------------------------------------------------------------------
  Bytes Format   Units      Label    Explanations
--------------------------------------------------------------------------------
   2-  6 I5      ---        Hseqno   HRI sequence number (G1)
   8-  9 I2      ---        Hsrcno   HRI source number (1)
  11- 12 I2      ct         cts0to3  Counts within 0-3" of source position
  14- 16 I3      ct         cts3to9  Counts within 3-9" of source position
  18- 20 I3      ct         cts9to18 Counts within 9-18" of source position
  22- 26 F5.3    ---        USProb   Probability that the source is unresolved
  27- 56 10I3    ct         ctR      Counts in annuli containing ~10% of
                                     total src cts
  57-106 10F5.1  arcsec     radR     Outer radii of the annular regions
 107-166 10F6.3  ct/arcsec2 denR     Photon densities in the annular regions
 168-173 F6.3    ct/ks      CR(S)PS  Count rate for assumed soft thermal point
                                      source (2)
 175-184 E10.5   mW/m2      FL(S)PS  Corresponding flux
 186-195 E10.5   ct/ks      CR(H)PS  C-rate for assumed hard thermal pt src (3)
 197-206 E10.5   mW/m2      FL(H)PS  Corresponding flux
 208-212 F5.3    arcsec     xtnt     Best estimate of source extent
 214-218 F5.2    ct/ks      CR(S)XS  C-rate for soft thermal source
                                     within estimated extent (2)
 220-229 E10.5   mW/m2      FL(S)XS  Corresponding flux
 231-240 E10.5   ct/ks      CR(H)XS  Count rate for hard thermal source
                                     within estimated extent (3)
 242-251 E10.5   mW/m2      FL(H)XS  Corresponding flux
 253-254 F2.0    arcsec     ulxtnt   Upper limit on source extent
 256-260 F5.2    ct/ks      CR(S)UXS Count rate for soft thermal source
                                     within upper limit extent (2)
 262-271 E10.5   mW/m2      FL(S)UXS Corresponding flux
 273-282 E10.5   ct/ks      CR(H)UXS Count rate for hard thermal source
                                     within upper limit extent (3)
 284-293 E10.5   mW/m2      FL(H)UXS Corresponding flux
 295-296 F2.0    arcsec     llxtnt   Lower limit on source extent
 298-302 F5.2    ct/ks      CR(S)LXS Count rate for soft thermal source
                                     within lower limit extent (2)
 304-313 E10.5   mW/m2      FL(S)LXS Corresponding flux
 315-324 E10.5   ct/ks      CR(H)LXS Count rate for hard thermal source
                                     within lower limit extent (3)
 326-332 F7.3    mW/m2      FL(H)LXS Corresponding flux
--------------------------------------------------------------------------------

Note (1): The 'Hsrcno' column gives the  HRI source number within the field.

Note (2): Assumed Thermal Bremmstrahlung spectrum  at kT=0.3 keV

Note (3): Assumed Thermal Bremmstrahlung spectrum  at kT=3.0 keV
--------------------------------------------------------------------------------


Byte-by-byte Description of file: hsrc.dat
--------------------------------------------------------------------------------
 Bytes Format  Units  Label    Explanations
--------------------------------------------------------------------------------
   2-  6 I5    ---    Hseqno   HRI Sequence Number (G1)
   8-  9 I2    ---    Hsrcno   HRI Source Number (1)
  11- 13 I3    arcsec csize    Detection cell size
  15- 22 F8.3  pix    y        Position in y
  24- 31 F8.3  pix    z        Position in z
  33- 36 F4.1  arcsec poserr   Position error
  38- 39 I2    h      RAh      Right Ascension (B1950) (hour)
  41- 42 I2    min    RAm      Right Ascension (B1950) (min)
  44- 45 I2    s      RAs      Right Ascension (B1950) (sec)
      47 A1    ---    DE-      Declination sign (B1950)
  48- 49 I2    deg    DEd      Declination (B1950) (deg)
  51- 52 I2    arcmin DEm      Declination (B1950) (arcmin)
  54- 55 I2    arcsec DEs      Declination (B1950) (arcsec)
  57- 62 F6.3  ct/ks  netcr    Corrected Count Rate per 1000 sec
  64- 68 F5.3  ct/ks  e_netcr  Error on Count Rate
  70- 74 F5.0  ct     bpcts    Counts in detect cell centered at best
                                   position (2)
  76- 80 F5.0  ct     eqcts    Counts in circle of equivalent area (2)
  82- 85 F4.0  ct     bp18cts  Counts in standard 18" circle at best
                                    position (3)
  87- 93 F7.3  ct     bp18bg   Background in 18" circle (3)
  95- 99 F5.3  ---    bp18scat Fraction of src cnts scattered out of
                                    18" circle (3)
 101-105 F5.3  ---    vcorr    Telescope vignetting correction at
                                    source position (4)
 107-111 F5.3  ---    dtfac    Dead time correction factor (4)
 113-117 F5.3  ---    qec      Detector quantum efficiency at source
                                    position (4)
 119-127 F9.2  s      exptime  Exposure time at source position (5)
 129-132 I4    ct     xccts    Counts in extended circle (6)
 134-140 F7.2  ct     xcbg     Background in extended circle (6)
 142-151 F10.7 ct     xcscat   Fraction of src cts scattered out of
                                    extended circle (6)
 153-163 F11.7 arcsec xcrad    Radius of extended circle (6)
 165-174 F10.7 ---    sizcor   Source xtent correction factor for cts/ks (7)
--------------------------------------------------------------------------------
Note (1): The 'Hsrcno' column gives the HRI source number within the field.

Note (2):  The number  of counts  in a  detect cell  centered at  the best
    position for each HRI source is given in the 'bpcts'  columns.  In the
    'eqcts' column, the number of counts in a circle of equivalent area is
    given.

Note (3):  Source  parameters are also  calculated for each  source at its
    best position in a standard circle with a radius of 18". The 'bp18cts'
    column lists source counts in the 18" circle,  and the 'bp18bg'  lists
    the expected background value  in  this  circle  determined  from  the
    background in a 5'   region about  the target  center,  scaled  by the
    circle  size and the exposure at  the source location.  The 'bp18scat'
    column  lists the fraction of total source counts scattered out of the
    18" circle.

Note (4):  The 'vcorr'  and 'dtfac'  columns list corrections made to the
    observation time; 'vcorr' gives the telescope vignetting correction at
    the source position and 'dtfac'  gives the dead time correction factor
    at  the time of the observation.  The 'qec'  column gives the detector
    quantum efficiency at the source position.

Note (5):  This column gives the total exposure time,  in seconds,  at the
    source position. The exposure time is corrected for intervals lost due
    to unacceptable aspect solution,  detector dead time,  and other event
    screening.   It may differ from the net time in the processed image if
    the source is not in the field of view for the entire observation.

Note (6):   These columns  give information  about extended  sources.  The
    number  of   counts  in   an  extended   circle  (that   circle  which
    circumscribes  all detect cells above threshold)  is given in 'xccts'.
    The  background in this extended circle  is given by 'xcbg'.  'xcscat'
    gives  the fraction  of source  counts scattered  out of  the extended
    circle;  and 'xcrad'  gives the  radius  of  the  extended  circle  in
    arcseconds.

Note (7):  This  column give  the size  correction factor,   'sizcor',  a
    parameter developed to adjust intensities for extended sources.  Since
    Rev 1 did not attempt to provide estimates of count rates or fluxes of
    extended sources, we have developed a new parameter, sizcor,  which is
    conceptually  similar to the classical beam broadening correction used
    by radio astronomers when  performing  drift  scans  with  single-dish
    telescopes.  Sizcor  serves  to  correct  all  intensity  measurements
    (optimized for point sources)   of  resolved  sources  for  the  X-ray
    brightness which is outside of the detection box. 'sizcor' can be used
    with any intensity measurement (counts, count rate, or flux) to obtain
    an  estimate for extended sources.  For a more complete description of
    sizcor, see the table <IX/23/source.dat>.
--------------------------------------------------------------------------------

Byte-by-byte Description of file: hris_sep.dat
--------------------------------------------------------------------------------
  Bytes  Format  Units   Label       Explanations
--------------------------------------------------------------------------------
    1- 5  I5     ---     Hseqno      HRI sequence number (G1)
       7  I1     ---     H1srcno     HRI source number (1)
    9-10  I2     arcsec  H1cell      Detection cell size
   12-19  F8.3   pix     H1y         Source y position
   21-28  F8.3   pix     H1z         Source z position
   30-32  F3.1   arcsec  H1poserr    Position uncertainty
   34-35  I2     ---     H2srcno     # of another source in same sequence
                                     detected with different cell size (1)
   37-39  I3     arcsec  H2cell      Detection cell size
   41-48  F8.3   pix     H2y         Second source y position
   50-57  F8.3   pix     H2z         Second source z position
   59-62  F4.1   arcsec  H2poserr    Second source position uncertainty
   64-71  F8.3   arcsec  separation  Separation between the two sources (2)
   73-79  F7.3   ---     nsep        Normalized separation (2)
--------------------------------------------------------------------------------
Note (1): These columns give the HRI source numbers, within a given field,
    of two sources which were detected with different cell sizes.

Note (2):  The  'separation'  column gives the pure separation between the
    two sources in arcseconds.   The  nsep  column  gives  the  normalized
    separation,  defined to be the ratio of separation to total positional
    uncertainty.   Total positional uncertainty  is defined as  the sum of
    individual  positional uncertainties,  with a systematic error of 3.5"
    added in quadrature to each individual uncertainty.
--------------------------------------------------------------------------------


Byte-by-byte Description of file: ifield.dat
--------------------------------------------------------------------------------
 Bytes Format  Units    Label   Explanations
--------------------------------------------------------------------------------
   1-  5 I5    ---      Iseqno  IPC Sequence Number (G1)
   7- 14 F8.2  s        ontime  Uncorrected exposure time (1)
  16- 23 F8.2  s        ltime   Corrected livetime (2)
  25- 29 F5.3  ct/pix2  sfbk    Field average background for soft band (3)
  31- 35 F5.3  ct/pix2  hfbk    Field average background for hard band (3)
  37- 41 F5.3  ct/pix2  bfbk    Field average background for broad band (3)
  43- 44 I2    h        RAh     Right Ascension (B1950) (hour)
  46- 47 I2    min      RAm     Right Ascension (B1950) (min)
  49- 50 I2    s        RAs     Right Ascension (B1950) (sec)
      52 A1    ---      DE-     Declination sign (B1950)
  53- 54 I2    deg      DEd     Declination (B1950) (deg)
  56- 57 I2    arcmin   DEm     Declination (B1950) (arcmin)
  59- 60 I2    arcsec   DEs     Declination (B1950) (arcsec)
  62- 68 F7.2  deg      nroll   Nominal Roll Angle (G2)
  70- 77 E8.4  cm-2     nH      Neutral Hydrogen Column Density (4)
  79- 87 E9.4  mJ/m2/ct sr2f    Flux conversion factor for soft band (5)
  89- 97 E9.4  mJ/m2/ct hr2f    Flux conversion factor for hard band (5)
  99-107 E9.4  mJ/m2/ct br2f    Flux conversion factor for broad band (5)
 109-113 F5.3  ---      alpha   Backgrnd map normaliz. factor for DSMAP (6)
 115-124 E10.4 ---      sbeta   BG map normaliz. factor for soft band BEMAP (6)
 126-135 E10.4 ---      hbeta   BG map normaliz. factor for hard band BEMAP (6)
 137-146 E10.4 ---      bbeta   BG map norm. factor for broad band BEMAP (6)
 148-153 F6.3  ---      bal     Time-averaged BAL for the sequence (7)
--------------------------------------------------------------------------------
Note (1):  The 'ontime'  column gives the total uncorrected exposure time,
    in seconds.

Note (2):  The 'ltime'  column gives the corrected livetime (in seconds);
    this  has   been  corrected  for  intervals   lost  because  of  Earth
    occultation, passage through the South Atlantic Anomaly,  unacceptable
    aspect solution,  and detector  dead time.   It is  the net  time,  in
    seconds, during which the detectors gathered data.

Note (3):   These  columns  give   the  field-averaged  background,   in
    counts/square pixel, for the soft (0.16-0.8 keV),  hard (0.8-3.5 keV),
    and broad (0.16-3.5 keV) bands.  The background has been obtained from
    an annulus between 8 and 15 arcminutes about the target center.

Note (4):  This column  gives the  column density  of neutral  hydrogen in
    atoms per cm^2^, integrated along the line of sight through our Galaxy
    in the direction of the field center of the observation.  Specified in
    exponential notation,   'nH'  values are obtained  from sky surveys of
    neutral hydrogen using 21 cm radio observations. The data are from the
    Bell Lab survey of Stark et al., private communication.

Note (5):  These columns  give  the  conversion  factor  from  count  rate
    (cts/sec)  to fluxes (ergs/cm**2/sec)  for the soft,  hard,  and broad
    bands.

Note (6):  These quantities describe the relative contributions of the two
    template background maps in  the  background  map  generated  for  the
    image.  The DSMAP template is generated by summing several deep survey
    exposures.  In  constructing  the  image  background  map,  the  DSMAP
    template is normalized  by  the  ratio  of  image  livetime  to  DSMAP
    livetime.  This  normalization factor,  'alpha',  is  the same for all
    energy bands.  The BEMAP template  is  generated  by  summing  several
    exposures of  the bright earth.  In  constructing the image background
    map,  the BEMAP template is normalized so that the total counts in the
    image (with sources subtracted) and the total counts in the sum of the
    normalized DSMAP and BEMAP are  the  same.   The  BEMAP  normalization
    factors, 'sbeta',  'hbeta',  and 'bbeta',  thus represent the ratio of
    BEMAP counts in the image to counts in the BEMAP template. They differ
    in the three energy bands. For more information on the construction of
    the  image background  map from  the DSMAP  and BEMAP  templates,  see
    Primini, et al. 1991ApJ...374..440P.

Note (7):  This column contains the  time-averaged gain of the instrument
    for the observation.
--------------------------------------------------------------------------------

Byte-by-byte Description of file: isrc.dat
--------------------------------------------------------------------------------
 Bytes Format  Units  Label     Explanations
--------------------------------------------------------------------------------
   2-  5 A4    ---    Iseqno     IPC sequence number (G1)
   7-  8 I2    ---    Isrcno     IPC source number in sequence (1)
  10- 13 I4    ---    reco       Rib and Edge Code (2)
  15- 16 A2    ---    pcod       Detection method and band (3)
      18 I1    ---    poscode    Position code (1 = within central 32'x32') (4)
  20- 21 I2    arcsec poserr     Position uncertainty
  23- 24 I2    h      RAh        Right Ascension (B1950) (hour)
  26- 27 I2    min    RAm        Right Ascension (B1950) (min)
  29- 30 I2    s      RAs        Right Ascension (B1950) (sec)
      32 A1    ---    DE-        Declination sign (B1950)
  33- 34 I2    deg    DEd        Declination (B1950) (deg)
  36- 37 I2    arcmin DEm        Declination (B1950) (arcmin)
  39- 40 I2    arcsec DEs        Declination (B1950) (arcsec)
  42- 47 F6.3  arcmin theta      Off-axis angle (5)
  49- 53 F5.3  ---    vcorr      Rev. 1B vignetting correction (6)
  55- 57 I3    ct     Scell      Soft counts in detect cell at source posn (7)
  59- 62 F4.1  ct     e_Scell    Error in detect cell counts in soft band (7)
  64- 66 I3    ct     Hcell      Hard counts in detect cell at source posn (7)
  68- 71 F4.1  ct     e_Hcell    Error in detect cell counts in hard band (7)
  73- 76 I4    ct     Bcell      Broad counts in detect cell at source posn (7)
  78- 81 F4.1  ct     e_Bcell    Error in detect cell counts in broad band (7)
  83- 87 F5.1  ct     Scellbk    Background in detect cell in soft band (8)
  89- 90 I2    ct     e_Scellbk  Error in detect cell bg in soft band (8)
  92- 97 F6.2  ct     Hcellbk    Background in detect cell in hard band (8)
  99-102 F4.2  ct     e_Hcellbk  Error in detect cell bg in hard band (8)
 104-109 F6.2  ct     Bcellbk    Background in detect cell in broad band (8)
 111-112 I2    ct     e_Bcellbk  Error in detect cell bg in broad band (8)
 114-124 E11.5 ct/s   Sccr       Soft band corrected count rate (9)
 126-135 E10.5 ct/s   e_Sccr     Error in soft band corrected count rate (9)
 137-147 E11.5 ct/s   Hccr       Hard band corrected count rate (9)
 149-158 E10.5 ct/s   e_Hccr    Error in hard band corrected count rate (9)
 160-169 E10.5 ct/s   Bccr       Broad band corrected count rate (9)
 171-180 E10.5 ct/s   e_Bccr     Error in broad band corrected count rate (9)
 182-192 E11.5 mW/m2  Sflux      Soft band flux (10)
 194-203 E10.5 mW/m2  e_Sflux    Error in soft band flux (10)
 205-215 E11.5 mW/m2  Hflux      Hard band flux (10)
 217-226 E10.5 mW/m2  e_Hflux    Error in hard band flux (10)
 228-237 E10.5 mW/m2  Bflux      Broad band flux (10)
 239-248 E10.5 mW/m2  e_Bflux    Error in broad band flux (10)
 250-254 F5.2  ---    Scorrsnr   Soft band signal-to-noise ratio
 256-260 F5.2  ---    Hcorrsnr   Hard band signal-to-noise ratio
 262-266 F5.2  ---    Bcorrsnr   Broad band signal-to-noise ratio
 268-271 F4.2  ---    f          Deep survey count rate correction (11)
--------------------------------------------------------------------------------
Note (1): The 'srcno' column gives the IPC source number within the field.

Note (2):  This column gives the ribs and edges code ('reco'),  a numeric
    flag  with nonzero values  indicating that the  detection cell (and/or
    frame  defined for "local detect")   falls near or on  a rib shadow or
    detector edge. The code is formed by concatenating a pair of two-digit
    numbers:  the first (thousands and hundreds columns)  gives the number
    (up to  16)  of  frame subcells  potentially shadowed  by the  ribs or
    masked-field edge;   the second  (tens and  units columns)   gives the
    number of subcells (up  to  09)   within  the  detect  box  which  are
    potentially shadowed.

Note (3):  The  'pcod'  column gives  the detection method  and band which
    describes  the origin  of the  position for  each IPC  source detected
    during standard  Rev 1B processing.  There  are six combinations which
    describe  the detection method and band  for each IPC source detected;
    these combinations are given by a two-digit code, with the first digit
    representing the detection method (L for L detect, or M for M detect),
    and  the second digit representing the spectral band used in detection
    (S for soft, H for hard, or B for broad). 'pcod'  describes from which
    method/band combination the  position  is  given;   it  is  the  first
    available one from the following prioritized order: MH,  MB,  MS,  LH,
    LB, LS.

Note (4):  The 'poscode'  column gives the position code for each source.
    The  position code will have bit 0 (the least significant bit)  set if
    the  source is within the central 32'x32'  of the field.  It will have
    bit 1 set if 'reco' > 0 (see above for description of 'reco').

Note (5): This is the distance of the source from the pointing position of
    the observation.

Note (6):  This column gives the Rev 1B vignetting correction and is used
    in determining the corrected count rates.

Note (7):   The 'Scell'  and 'e_Scell'  columns  give the number of source
    counts in the  detect cell and  the corresponding error  at the source
    position in the soft band (0.16-0.8 keV); 'Hcell'  and 'e_Hcell'  give
    these  quantities  for  the  hard  band  (0.8-3.5  keV);  'Bcell'  and
    'e_Bcell' give these quantities for the broad band (0.16-3.5 keV).

Note (8):  The  'Scellbk'  and  'e_Scellbk'  columns  give the  number of
    background counts  and the corresponding  error in the  detect cell in
    the soft band. 'Hcellbk' and 'e_Hcellbk' give these quantities for the
    hard  band;  'Bcellbk'  and 'e_Bcellbk'  give these quantities for the
    broad band. The background counts are determined either from counts in
    a  region surrounding the detect cell (LDETECT)  or from counts in the
    corresponding detect  cell of  the background  map (MDETECT).   In the
    latter case, the error in the background counts is assumed to be zero.

Note (9):  The 'Sccr'  and 'e_Sccr'  columns give the soft band corrected
    count  rate (in counts/sec)  and the corresponding error.  'Hccr'  and
    'e_Hccr' give these quantities for the hard band; 'Bccr'  and 'e_Bccr'
    give  these quantities for the broad band.  In general,  the corrected
    count rate is determined as follows:

         ccr = (cell-cellbk) * vcorr * CMS * CPRF /  livetime

    vcorr is described above.  CPRF corrects for source photons which fall
    outside the detect  cell.   Detect  cell  sizes  are  chosen  so  that
    CPRF=1.13  for  all  energy  bands.   CMS  corrects  for  large  angle
    scattering   intrinsic  in   the  HEAO-2   mirror.   This   factor  is
    energy-dependent  and has a value  of 1.09 for the  soft band and 1.18
    for the  hard and broad  bands.  For deep  survey sources,  additional
    minor count rate corrections may be necessary.  These are described in
    the "f" column below.

Note (10): The 'Sflux'  and 'e_Sflux'  columns give the soft band flux (in
    ergs/cm**2/s  or mW/m2)   and the  corresponding error.   'Hflux'  and
    'e_Hflux'  give these quantities for  the  hard  band;   'Bflux'   and
    'e_Bflux' give these quantities for the broad band.

Note (11): This column gives the deep survey count rate correction factor;
    this  number will  be 0  if the  source was  excluded from  the DSMAP.
    Otherwise,   it will  be equal  to the  ratio of  the livetime  of the
    sequence  number to  the livetime  of the  DSMAP.  This  correction is
    necessary  because the  DSMAP templates  used to  construct background
    maps are generated from the deep survey observations themselves.  Thus
    calculation of count  rates for deep  survey sources may  be biased by
    inclusion of source counts in the background map.  Correction for this
    bias   is   described   in   detail   in   Primini   et   al.    1991.
    (=1991ApJ...374..440P)
--------------------------------------------------------------------------------

Byte-by-byte Description of file: ispec.dat
--------------------------------------------------------------------------------
  Bytes  Format  Units  Label    Explanations
--------------------------------------------------------------------------------
   2-  5 A4      ---    Iseqno   IPC sequence number (G1)
   7-  8 I2      ---    Isrcno   IPC source no. within sequence (1)
  10- 14 F5.0    pix2   Barea    pixels Area of background region (2)
  16- 20 F5.0    pix2   Sarea    pixels Area of source region (2)
  22- 31 F10.7   ---    hr       Hardness ratio (3)
  33- 43 F11.7   ---    E_hr     Positive hardness ratio error (3)
  45- 55 F11.7   ---    e_hr     Negative hardness ratio error (real) (3)
  56-135 16F5.0  ---    phbk     Pulse height spectrum of background region (4)
 136-215 16F5.0  ---    pibk     Pi spectrum of background region (5)
 216-295 16F5.0  ---    ph       Pulse height spectrum of source (6)
 296-375 16F5.0  ---    pi       Pi spectrum of source (7)
--------------------------------------------------------------------------------
Note (1):  This column gives the IPC source number within the field,  for
    each IPC source detected in the Einstein Deep Survey.

Note (2):  These columns give  the  area,   in  square  pixels,   for  the
    background  region and the source region used to accumulate counts for
    the IP/RHA spectra.  The background region is nominally a 5'-6'annulus
    around the source, with any other sources excluded.  The source region
    is nominally  a 3'  circle around the  source,  with any other sources
    excluded. An IPC pixel is 8"x8".

Note (3):  These columns give  the hardness ratio and  its plus and minus
    error,  from Rev1B  processing.  The  hardness ratio  for a  source is
    defined as the ratio of the difference between the number of counts in
    the hard and soft bands to the sum of these quantities:
                  counts(hard) - counts(soft)
            hr =  ---------------------------
                  counts(hard) + counts(soft)
    Note that the error  values are  assumed symmetric  and are  thus only
    approximate.

Note (4):  These columns give the pulse height spectrum of the background
    region for each of the 16 pha channels.

Note (5):  These columns give the pi spectrum of the background region for
    each of the 16 pi channels.

Note (6):  These columns give the pulse height spectrum of the source for
    each of the 16 pha channels.

Note (7): These columns give the pi spectrum of the source for each of the
    16 pi channels.
--------------------------------------------------------------------------------

Byte-by-byte Description of file: icomp.dat
--------------------------------------------------------------------------------
 Bytes Format Units  Label      Explanations
--------------------------------------------------------------------------------
  1- 5   I5    ---   Iseqno     IPC sequence number (G1)
  7- 8   I2    ---   Isrcno     IPC source number in sequence (1)
 10-11   A2    ---   comp       [LMBHS] Detection method and band (2)
 13-19   F7.3  pix   ypix       Source y position
 21-26   F6.3  pix   e_ypix     Error in y position
 28-34   F7.3  pix   zpix       Source z position
 36-41   F6.3  pix   e_zpix     Error in z position
 43-46   I4    ct    cellcts    Counts in detect cell centered at y,z (3)
 48-53   F6.3  ct    e_cellcts  Error in detect cell counts (3)
 55-61   F7.3  ct    cellbk     Background in detect cell (3)
 63-68   F6.3  ct    e_cellbk   Error in background (3)
 70-77   F8.3  ct    netccts    Net source counts in detect cell
 79-84   F6.3  ct    e_netccts  Error in net counts
 86-92   F7.3  ct    thr        Threshold counts in detect cell for source
                                   detection.
 94-98   F5.2  ---   snr        Count rate signal-to-noise ratio
--------------------------------------------------------------------------------
Note (1): The 'Isrcno' column gives the  IPC source number within the field.

Note (2):  This  column  gives  a  two-digit  code  which  identifies  the
    detection  method and  band for  each IPC  source.  The  two detection
    method  codes are L and M,  for LDETECT and MDETECT.  The band will be
    identified  by an S,  H,  or B (for soft,  hard,  or broad).  Thus,  a
    typical entry in  this column  might be  MH for  an MDETECT  hard band
    detection.

Note (3):  The  'cellcts'  and  'e_cellcts'  columns  give the  counts and
    corresponding error  in the detect  cell centered at  the given source
    position,  y,z.  Likewise,  the  'cellbk'  and  'e_cellbk'   give  the
    background counts  and corresponding error in  the source detect cell.
    The background  counts are determined  either from counts  in a region
    surrounding   the  detect  cell  (LDETECT)   or  from  counts  in  the
    corresponding detect  cell of  the background  map (MDETECT).   In the
    latter case, the error in the background counts is assumed to be zero.
--------------------------------------------------------------------------------


Byte-by-byte Description of file: ipchri.dat
--------------------------------------------------------------------------------
 Bytes Format  Units     Label     Explanations
--------------------------------------------------------------------------------
  2- 5 A4      ---       Iseqno    IPC sequence number (G1)
  7- 8 I2      ---       Isrcno    IPC source number (1)
 10-11 I2      h         RAh       Right Ascension (B1950) (hour)
 13-14 I2      min       RAm       Right Ascension (B1950) (min)
 16-20 F5.2    s         RAs       Right Ascension (B1950) (sec)
    22 A1      ---       DE-       Declination sign (B1950)
 23-24 I2      deg       DEd       Declination (B1950) (deg)
 26-27 I2      arcmin    DEm       Declination (B1950) (arcmin)
 29-32 F4.1    arcsec    DEs       Declination (B1950) (arcsec)
 34-35 I2      arcsec    ipcperr   IPC source position uncertainty (2)
 37-41 F5.2    ---       ipchsnr   IPC Hard band signal-to-noise ratio
 43-47 I5      ---       Hseqno    ?=0 HRI sequence number (G1)
 49-50 I2      ---       Hsrcno    ?=0 HRI source number
 52-53 I2      h         RA(HRI)h  HRI Right Ascension (B1950) (hour)
 55-56 I2      min       RA(HRI)m  HRI Right Ascension (B1950) (min)
 58-61 F4.1    s         RA(HRI)s  HRI Right Ascension (B1950) (sec)
    63 A1      ---       DE(HRI)-  HRI Declination sign (B1950)
 64-65 I2      deg       DE(HRI)d  HRI Declination (B1950) (deg)
 67-68 I2      arcmin    DE(HRI)m  HRI Declination (B1950) (arcmin)
 70-71 I2      arcsec    DE(HRI)s  HRI Declination (B1950) (arcsec)
 73-76 F4.1    arcsec    hriperr   HRI source position uncertainty (3)
 78-83 F6.1    arcsec    theta     Separation between IPC and HRI sources (4)
 85-89 F5.1    ---       nsep     Normalized separation (4)
--------------------------------------------------------------------------------
Note (1):  These  columns give the  IPC sequence number  and source number
    within that field for Einstein Deep Survey IPC sources.

Note (2): This column gives the positional uncertainty, in arcseconds,  of
    the given IPC source.

Note (3): This column gives the positional uncertainty, in arcseconds,  of
    the given HRI source.

Note (4):  'theta'  gives the  separation  between  IPC  and  HRI  sources
    detected  in corresponding fields for each target in the Einstein Deep
    Survey. The 'nsep'  column gives the normalized separation between IPC
    and  HRI sources,  defined to be the ratio of separation to sum of IPC
    and HRI positional uncertainties. A systematic uncertainty of 3.5"  is
    added  in quadrature to  the HRI uncertainty  before calculating nsep.
    The  IPC position error also includes a systematic uncertainty,  which
    depends on source position, and ranges from 25" to 45".

--------------------------------------------------------------------------------

Byte-by-byte Description of file: ihsample.dat
--------------------------------------------------------------------------------
 Bytes  Format Units  Label   Explanations
--------------------------------------------------------------------------------
   1- 4   I4   ---    Iseqno  IPC sequence number (1)
   6- 7   I2   ---    Isrcno  IPC source number (1)
   9-13   I5   ---    Hseqno  ?=0 HRI sequence number (2)
     15   I1   ---    Hsrcno  ?=0 HRI source number of matching HRI source (2)
--------------------------------------------------------------------------------
Note (1):  These  columns give the  IPC sequence number  and source number
    within that  field for Einstein  Deep Survey IPC  sources greater than
    4.5 sigma which also have a coincident HRI source detection.

Note (2):  These  columns give the  HRI sequence number  and source number
    within that field for Einstein Deep Survey HRI sources which also have
    a coincident IPC source detection greater than 4.5 sigma. Coincidences
    are  defined as an IPC-HRI pair with a normalized separation of two or
    less.
       The normalized separation is described as:

                  IPC-HRI separation
           ------------------------------------
           sum of IPC and HRI positional errors

    This  threshold  was   determined   empirically   by   examining   the
    distribution of normalized separations for all IPC-HRI pairs.
--------------------------------------------------------------------------------


Byte-by-byte Description of file: sample.dat
--------------------------------------------------------------------------------
  Bytes Format  Units     Label   Explanations
--------------------------------------------------------------------------------
    1-  4 I4    ---       Iseqno  IPC sequence number (G1)
    6-  7 I2    ---       Isrcno  IPC source number (1)
    9- 10 I2    h         RAh     Right Ascension (1950) (hour)
   12- 13 I2    min       RAm     Right Ascension (1950) (min)
   15- 16 I2    s         RAs     Right Ascension (1950) (sec)
       18 A1    ---       DE-     Declination Sign (1950)
   19- 20 I2    deg       DEd     Declination (1950) (deg)
   22- 23 I2    arcmin    DEm     Declination (1950) (arcmin)
   25- 26 I2    arcsec    DEs     Declination (1950) (arcsec)
   28- 29 I2    arcsec    Iposerr IPC position uncertainty
   31- 37 F7.4  10-17W/m2 Iflux   IPC source flux (*1.0E14) (2)
   39- 44 F6.4  10-17W/m2 e_Iflux IPC flux error (*1.0E14)
   46- 51 F6.3  ---       Isnr    IPC count rate signal-to-noise ratio
   53- 57 I5    ---       Hseqno  ?=0 HRI sequence number  (3)
       59 I1    ---       Hsrcno  ?=0 HRI src # of HRI src (if any) that
                                           matches IPC src  (3)
   61- 63 I3    arcsec    Hcell   HRI detection cell size
   65- 91 A27   ---       Hpos    HRI B1950 source position (sexag.)
   93- 97 F5.2  arcsec    e_Hpos  HRI position uncertainty
   99-104 F6.3  ct/ks     Hrate   HRI source count rate per 1000 s (4)
  106-110 F5.3  ct/ks     e_Hrate HRI rate error
      112 A1    ---       l_Vmag  [> ] uncertainty in Vmag
  114-117 F4.1  mag       Vmag    ? Optical visual magnitude
      119 A1    ---       l_fxfv  [> ] uncertainty in fxfv
  121-124 F4.1  ---       fxfv    ? Log of ratio of broad x-ray flux/optical
                                        flux (5)
  126-129 F4.2  ---       z       ? OPT redshift
  131-136 A6    ---       ID      Identification  (6)
--------------------------------------------------------------------------------
Note (1):  This column gives the IPC  source number within that field for
    Einstein Deep Survey IPC sources contained in the 4.5 sigma signal-to-
    noise-limited sample.

Note (2):  This column  give the  hard band  IPC source  flux in  units of
    10^-14^ ergs/cm^2^/s.

Note (3):  These  columns give the  HRI sequence number  and source number
    within that  field for Einstein  Deep Survey HRI  sources contained in
    the  4.5 sigma signal-to-noise-limited sample.  Note that there may be
    more than one HRI detection for each IPC source.

Note (4):  These columns  give the  HRI count  rate per  1000 sec  and the
    corresponding  error for  each HRI  source detected  in the  4.5 sigma
    sample.    The  count  rates  have   been  corrected  for  vignetting,
    scattering, dead time, and detector efficiency.

Note (5):   This column gives the logarithm of  the ratio of x-ray flux in
    the IPC broad band (0.16-3.5 keV) to the optical flux.

Note (6): This column gives the optical identification for the IPC source.
    Current identifications include: Galaxy, Star, and QSO.
--------------------------------------------------------------------------------

Byte-by-byte Description of file: optinfo.dat
--------------------------------------------------------------------------------
 Bytes Format Units  Label   Explanations
--------------------------------------------------------------------------------
   4- 7 I4     ---   Iseqno  IPC sequence number (G1)
  13-14 I2     ---   Isrcno  IPC source number (1)
     16 A1     ---   l_Vmag  [> ] limit to the visual magnitude
  18-21 F4.1   mag   Vmag    ? Visual magnitude
     23 A1     ---   l_fxfv  [> ] '>' when fxfv is a lower limit
  25-28 F4.1   ---   fxfv    ? Log of ratio of broad x-ray flux/optical flux (2)
  32-35 F4.2   ---   z       ? Redshift
  39-44 A6     ---   ID      Galaxy Identification  (3)
--------------------------------------------------------------------------------
Note (1): The source number within that field for Einstein Deep Survey IPC
    sources for which there is optical information.

Note (2):   This column gives the logarithm of  the ratio of x-ray flux in
    the broad band (0.16-3.5 keV) to the optical flux.

Note (3): This column gives the optical identification for the IPC source.
    Current identifications include: Galaxy, Star, and QSO.
--------------------------------------------------------------------------------


Global Notes:

Note (G1): The 'Seqno' column gives the Einstein Observatory sequence number,
    a two  to five digit  number which uniquely  identifies the observation.
    The numbers  were  assigned  sequentially  at  the  time  of  proposal
    submission.

Note (G2): The 'nroll' gives the angle which measures the roll of the
    spacecraft about the axis  pointing  towards  the  field  center.   It
    provides the  angular orientation  of the  focal plane  detectors with
    respect to the celestial coordinate grid. A positive value of the roll
    angle  indicates a  clockwise rotation  of the  (detector's projected)
    field when viewing the celestial sphere.

History:
    Prepared from the tables available at the "ADS Catalogue Service"
    (CfA, Harvard-Smithsonian Center for Astrophysics, Cambrigde MA)


================================================================================
(End)                                          Patricio Ortiz [CDS]  20-Apr-1999

Go to ADC Home Page