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IPCDEEP: Help

IPCDEEP - Einstein Catalog IPC Deep Survey


Overview

IPCDEEP is created from a table containing basic source parameters for each of the 178 IPC sources detected by the Einstein Deep Survey. 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.

Catalog Bibcode

1991ApJ...374..440P

References

Primini, F.A., Murray, S.S., Huchra, J., Schild, R., Burg, R., and Giacconi, R.
  Imaging X-ray Astronomy, ed. M. Elvis (Cambridge, Cambridge University Press),
  p. 337.

Primini, F.A., Murray, S.S., Huchra, J., Schild, R., Burg, R., and Giacconi, R.
  1991, Ap.J., 374, 440.

Parameters

BII
The galactic longitude of the object.

Broad_Background_Counts
The number of background counts in the detect cell in 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).

Broad_Background_Error
The background counts error in the detect cell in the broad band. In the case of counts from the background map, the error in the background counts is assumed to be zero.

Broad_Counts
The number of source counts in the detect cell at the source position for the broad band (0.16-3.5 keV).

Broad_Counts_Error
The source counts error at the source position for the broad band (0.16-3.5 keV).

Broad_Flux
The broad band flux (in ergs/cm**2/s).

Broad_Flux_Error
The broad band flux error.

Broad_SNR
The broad band signal-to-noise ratios.

Correction_Factor
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.

Count_Rate
The broad band corrected count rate (in counts/sec). In general, the corrected count rate is determined as follows:

Corr Count Rate = (Counts - bkgrd counts) * vign corr * CMS * CPRF / livetime

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 corrections are descripted under Deep Survey Count Rate Correct.

Count_Rate_Error
The broad band corrected count rate error.

Dec
The Declination of the object.

Detect_Method
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). This also 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.

Hard_Background_Counts
The number of background counts in the detect cell in the hard 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).

Hard_Background_Error
The background counts error in the detect cell in the hard band. In the case of counts from the background map, the error in the background counts is assumed to be zero.

Hard_Corr_Count_Rate
The hard band corrected count rate (in counts/sec). In general, the corrected count rate is determined as follows:

Corr Count Rate = (Counts - bkgrd counts) * vign corr * CMS * CPRF / livetime

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 corrections are descripted under Deep Survey Count Rate Correct.

Hard_Count_Rate_Error
The hard band corrected count rate error.

Hard_Counts
The number of source counts in the detect cell at the source position for the hard band (0.8-3.5 keV).

Hard_Counts_Error
The source counts error at the source position for the hard band (0.8-3.5 keV).

Hard_Flux
The hard band flux (in ergs/cm**2/s).

Hard_Flux_Error
The hard band flux error.

Hard_SNR
The hard band signal-to-noise ratios.

LII
The galactic latitude of the object.

Name
Name is derived from the concatonation of the Sequence Number and the Source Number.

Off_Axis_Angle
The off-axis angle, in arcminutes, is the distance of the source from the pointing position of the observation.

Pos_Code
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 Rib Edge code > 0.

Pos_Uncert
The positional uncertainty, in arcseconds.

RA
The Right Ascension of the object.

Rib_Edge_Code
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.

Sequence_Num
This 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.

Soft_Background_Counts
The number of background counts in the detect cell in the soft 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).

Soft_Background_Error
The background counts error in the detect cell in the soft band. In the case of counts from the background map, the error in the background counts is assumed to be zero.

Soft_Corr_Count_Rate
The soft band corrected count rate (in counts/sec). In general, the corrected count rate is determined as follows:

Corr Count Rate=(Counts - bkgrd counts) * vign corr * CMS * CPRF / livetime

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 corrections are descripted under Deep Survey Count Rate Correct.

Soft_Count_Rate_Error
The soft band corrected count rate error.

Soft_Counts
The number of source counts in the detect cell at the source position in the soft band (0.16-0.8 keV).

Soft_Counts_Error
The source counts error at the source position in the soft band (0.16-0.8 keV).

Soft_Flux
The soft band flux (in ergs/cm**2/s).

Soft_Flux_Error
The soft band flux error.

Soft_SNR
The soft band signal-to-noise ratios.

Source_Num
The IPC source number within the field.

Vignetting_Correction
The Rev 1B vignetting correction and is used in determining the corrected count rates.


Contact Person

Questions regarding the IPCDEEP database table can be addressed to the HEASARC User Hotline.
If you have any problems, please consult the help page or mail ledas-help@star.le.ac.uk
 
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