INTVARCAT - INTEGRAL/ISGRI Catalog of Variable X-Ray Sources

Overview

In 6 years of operation, INTEGRAL/ISGRI revealed more than 500 sources. Many of these sources are variable. Taking into account that nearly half of INTEGRAL/ISGRI sources are new and many of them are still unidentified, the variability properties of the sources can serve as additional parameters that may help to classify and identify the unknown sources. In order to study the variability properties of the sources detected by INTEGRAL/ISGRI, the authors have developed a method to quantify the variability of a source which is described in their paper. They have compiled a catalog of the sources that fit their criteria of variability.

This catalog gives the values of fractional variability, the flux, and the corresponding 2-sigma errors of the sources from the INTEGRAL Reference Catalog (CDS Cat. J/A+A/411/L59: INTVARCAT in Browse) version 30. The data are given for 3 energy bands: 20-40, 40-100, and 100-200 keV. The exposure times of the sources are given for each energy band only if the source was detected in the given band. This table also gives the source type according to the reference catalog. If the source is localized in more then one map then the weighted mean values of the flux and variability are given. The sources active during specific time periods and not detected at the total variability map are indicated with "b" letter in the source_flag parameter. The sources detected only in the total variability map are indicated with an "i" letter value for this parameter, while a letter "g" indicates that the source was affected by the "ghost" of another source. The map_det* parameters specify the time period map(s) in which the source was visible, where the presence of an 'X' following a map number means that the source was not detected in the respective significance map, and that a lower limit for the fractional variability is given in such a case.

Catalog Bibcode

2010A&A...522A..68T

References

The catalog of variable sources detected by INTEGRAL.
I. Catalog and techniques.
    Telezhinsky I., Eckert D., Savchenko V., Neronov A., Produit N.,
    Courvoisier T.J.-L.
   <Astron. Astrophys. 522, A68 (2010)>
   =2010A&A...522..A68T

Provenance

This table was created by the HEASARC in December 2010 based on CDS Catalog J/A+A/522/A68 file table3.dat.

HEASARC Implementation

The HEASARC has added the positional information for the sources (not present in the original version of this table) from their positions as given in the version (31) of the INTEGRAL Reference Catalog which was extant at the time it created this present table. Also, the exposure times of the sources were converted by the HEASARC into seconds from the kiloseconds units given in the original table.

Parameters

Source_Number
The INTEGRAL Variable Catalog source number, mostly in order of increasing J2000 RA, except for sources 196-202 which were detected only in the total variability map. This is not the same source numbering scheme as is used in the INTEGRAL Reference Catalog, notice.

Name
The INTEGRAL Reference Catalog source name.

RA
The Right Ascension of the source in the specified equinox. The HEASARC has added the positional information for the sources (not present in the original version of this table) from their positions as given in the INTEGRAL Reference Catalog, Version 31.

Dec
The Declination of the source in the specified equinox. The HEASARC has added the positional information for the sources (not present in the original version of this table) from their positions as given in the INTEGRAL Reference Catalog, Version 31.

LII
The Galactic Longitude of the source.

BII
The Galactic Latitude of the source.

Source_Flag
This flag parameter contains the following information on source peculiarities:

         b = sources active during specific time periods and not detected at
             the total variability map
         i = sources detected only at the total variability map
         g = source variability is slightly affected by a "ghost", can go
             along with "b" and "i" flags

Var_20_40keV_Limit
This flag parameter is set to '<' if the corresponding parameter is an upper limit (3-sigma) rather an actual value.

Var_20_40keV
The fractional variability V of the source in the 20-40 keV band. This parameter is defined in Section 3 of the reference paper. If the source is localized in more then one map, then the weighted mean value of the variability is given.

Var_20_40keV_Error
The 2-sigma uncertainty in the value of the corresponding parameter.

Map_Det_20_40keV
The map number(s) in which the source was detected in the 20-40 keV band. The 6 years of data included in the present analysis was divided into 3 equal subsequent time periods, labelled maps 1, 2 and 3, approximately of 2 years each. This was done to detect transient sources that would be difficult or impossible to detect in the map integrated over the entire time period. An 'X' following a map value (changed from an asterisk in the original table) means that the source was not detected at the respective significance map, and that a lower limit for the fractional variability is given in such a case.

Flux_20_40keV_Limit
This flag parameter is set to '<' if the corresponding parameter is an upper limit (3-sigma) rather an actual value.

Flux_20_40keV
The source flux in the 20-40 keV band, in units of 10^-11 erg cm^-2 s^-1. The conversion factor used was 1 ct/s (20-40 keV) = 4.46 x 10^-11 erg cm^-2 s^-1. The authors used the INTEGRAL Off-line Scientific Analysis (OSA) software, Version 7.0 ARFs and RMFs and simulated a source with a Crab-like spectrum and then used XSPEC to find the count rate to flux conversion factor. It should be noted that this method depends on the shape of the source spectrum, and that there are several ARFs for different periods of the mission, and thus the fluxes cannot be considered to be fully reliable. If the source is localized in more then one map, then the weighted mean value of the flux is given.

Flux_20_40keV_Error
The 2-sigma uncertainty in the value of the corresponding parameter.

Exposure_20_40keV
The exposure time of the source, in the 20-40 keV band, in seconds (converted by the HEASARC from the kiloseconds units given in the original table). This is given only if the source was detected in this band.

Var_40_100keV_Limit
This flag parameter is set to '<' if the corresponding parameter is an upper limit (3-sigma) rather an actual value.

Var_40_100keV
The fractional variability V of the source in the 40-100 keV band. This parameter is defined in Section 3 of the reference paper. If the source is localized in more then one map, then the weighted mean value of the variability is given.

Var_40_100keV_Error
The 2-sigma uncertainty in the value of the corresponding parameter.

Map_Det_40_100keV
The map number(s) in which the source was detected in the 40-100 keV band. The 6 years of data included in the present analysis was divided into 3 equal subsequent time periods, labelled maps 1, 2 and 3, approximately of 2 years each. This was done to detect transient sources that would be difficult or impossible to detect in the map integrated over the entire time period. An 'X' following a map value (changed from an asterisk in the original table) means that the source was not detected at the respective significance map, and that a lower limit for the fractional variability is given in such a case.

Flux_40_100keV_Limit
This flag parameter is set to '<' if the corresponding parameter is an upper limit (3-sigma) rather an actual value.

Flux_40_100keV
The source flux in the 40-100 keV band, in units of 10^-11 erg cm^-2 s^-1. The conversion factor used was 1 ct/s (40-100 keV) = 9.247 x 10^-11 erg cm^-2 s^-1. The authors used the INTEGRAL Off-line Scientific Analysis (OSA) software, Version 7.0 ARFs and RMFs and simulated a source with a Crab-like spectrum and then used XSPEC to find the count rate to flux conversion factor. It should be noted that this method depends on the shape of the source spectrum, and that there are several ARFs for different periods of the mission, and thus the fluxes cannot be considered to be fully reliable. If the source is localized in more then one map, then the weighted mean value of the flux is given.

Flux_40_100keV_Error
The 2-sigma uncertainty in the value of the corresponding parameter.

Exposure_40_100keV
The exposure time of the source, in the 40-100 keV band, in seconds (converted by the HEASARC from the kiloseconds units given in the original table). This is given only if the source was detected in this band

Var_100_200keV_Limit
This flag parameter is set to '<' if the corresponding parameter is an upper limit (3-sigma) rather an actual value.

Var_100_200keV
The fractional variability V of the source in the 100-200 keV band. This parameter is defined in Section 3 of the reference paper. If the source is localized in more then one map, then the weighted mean value of the variability is given.

Var_100_200keV_Error
The 2-sigma uncertainty in the value of the corresponding parameter.

Map_Det_100_200keV
The map number(s) in which the source was detected in the 100-200 keV band. The 6 years of data included in the present analysis was divided into 3 equal subsequent time periods, labelled maps 1, 2 and 3, approximately of 2 years each. This was done to detect transient sources that would be difficult or impossible to detect in the map integrated over the entire time period. An 'X' following a map value (changed from an asterisk in the original table) means that the source was not detected at the respective significance map, and that a lower limit for the fractional variability is given in such a case.

Flux_100_200keV_Limit
This flag parameter is set to '<' if the corresponding parameter is an upper limit (3-sigma) rather an actual value.

Flux_100_200keV
The source flux in the 100-200 keV band, in units of 10^-11 erg cm^-2 s^-1. The conversion factor used was 1 ct/s (100-200 keV) = 3.638 x 10^-10 erg cm^-2 s^-1. The authors used the INTEGRAL Off-line Scientific Analysis (OSA) software, Version 7.0 ARFs and RMFs and simulated a source with a Crab-like spectrum and then used XSPEC to find the count rate to flux conversion factor. It should be noted that this method depends on the shape of the source spectrum, and that there are several ARFs for different periods of the mission, and thus the fluxes cannot be considered to be fully reliable. If the source is localized in more then one map, then the weighted mean value of the flux is given.

Flux_100_200keV_Error
The 2-sigma uncertainty in the value of the corresponding parameter.

Exposure_100_200keV
The exposure time of the source, in the 100-200 keV band, in seconds (converted by the HEASARC from the kiloseconds units given in the original table). This is given only if the source was detected in this band

Source_Type
The source type according to the INTEGRAL Reference Catalog.

Class
The HEASARC Browse object classification based on the source_type parameter value.

Contact Person

Questions regarding the INTVARCAT database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:29:22 EDT