BATSEEOCAT - CGRO/BATSE Earth Occultation Catalog of Low-Energy Gamma-Ray Sources

Overview

This table contains the CGRO/BATSE Earth Occultation Catalog of Low-Energy Gamma-Ray Sources. The Burst and Transient Source Experiment (BATSE), aboard the Compton Gamma Ray Observatory (CGRO), provided a record of the low-energy gamma-ray sky (20 - 1000 keV band) between 1991 April and 2000 May (a 9.1 year period). Using the Earth Occultation Technique to extract flux information, a catalog of sources using data from the BATSE large area detectors has been prepared. The first part of the catalog consists of results from the monitoring of 58 sources, mostly Galactic. For these sources, the authors included tables of flux and spectral data, and outburst times for transients, in their published paper.

The authors also performed a deep-sampling of 180 objects (including the aforementioned 58 objects) combining data from the entire 9.1 year BATSE dataset. (One extra object, GRO J1735-27, has been added in this HEASARC table in addition to the 179 objects discussed in the reference paper). Source types considered were primarily accreting binaries, but a small number of representative active galaxies, X-ray-emitting stars, and supernova remnants were also included. The deep sample results include definite detections of 83 objects and possible detections of 36 additional objects. The definite detections spanned three classes of sources: accreting black hole and neutron star binaries, active galaxies and supernova remnants. Flux data for the deep sample are presented in four energy bands: 20-40, 40-70, 70-160, and 160-430 keV. The limiting average flux level (9.1 years) for the sample varies from 3.5 to 20 mCrab (5 sigma) between 20 and 430 keV, depending on systematic error, which in turn is primarily dependent on the sky location. To strengthen the credibility of detection of weaker sources (5-25 mCrab), the authors generated Earth occultation images, searched for periodic behavior using FFT and epoch folding methods, and critically evaluated the energy-dependent emission in the four flux bands.

For more information, visit the website https://heasarc.gsfc.nasa.gov/docs/cgro/batse/hilev/highlevel.html or refer to the Harmon et al. 2004 paper.

Catalog Bibcode

2004ApJS..154..585H

References

    The Burst and Transient Source Experiment (BATSE) Earth Occultation
    Catalog of Low-Energy Gamma-Ray Sources

    B. A. Harmon, C. A. Wilson, G. J. Fishman, V. Connaughton, W. Henze,
    W. S. Paciesas, M. H. Finger, M. L. McCollough, M. Sahi, B. Peterson,
    C. R. Shrader, J. E. Grindlay, D. Barret 2004, ApJS, 154, 585.

Provenance

This table was first created by the HEASARC in June 2004 based on a table supplied by one of the authors. The HEASARC updated the table and added the data products in July 2006.

Data Products

Each entry in this table corresponds to a separate source for which useful BATSE Earth-occultation light curve and spectral data can be derived. For many sources, there is a summary light curve in simple text format covering essentially the full mission. There are also FITS data products resulting from the Earth occultation analysis. The latter can be easily browsed with FTOOLS such as "fplot", "fv", or studied and manipulated in greater detail with the FTOOL "bodfluxhis". Spectra (16-channels) and corresponding response matrices can be created using the "bod2pha" and "bod2rmf" FTOOLS (sample pha and rsp files have also been created for some sources in selected time ranges).

The XXX_TJD1_TJD2.txt files in (some of the) source directories summarize the data in ASCII format. For instance, herx-1_8361_11690.txt has the following information:

          TJD          TJD         Photon Flux  Uncertainty

       8363.0398       8363.9517    0.0827262    0.0481065
       8364.0138       8364.9905   -0.0518658    0.0335929
       8365.0133       8365.9899   -0.0290051    0.0328237
       8366.0266       8366.9638   -0.0526592    0.0365290
       8367.0005       8367.4831   -0.0116533    0.0101044
       8368.0392       8368.4569   0.00460322    0.0109705
       8369.2078       8369.9896  0.000291039   0.00929573
       .
       .
       .

The basic source light curves (in FITS format) are in files named XXX_TJD1_TJD2_his.fits, whereas the daily-averaged occultation histories are in files named XXX_TJD1_TJD2_nhis.fits, where the characters XXX represent the source name, and TJD1 and TJD2 are the beginning and ending Truncated Julian Dates (TJD) of the observations contained in the files.

Parameters

Name
The BATSE Catalog name of the object.

Detect_Flag
This parameter is set to "d" to indicate a firm detection.

Alt_Name
An alternative name recognized by SIMBAD if the BATSE Catalog name was not so recognized, or another well-known name of the object.

Object_Type
An identification of the object type, using the following classes given by acronyms (as well as others such as BL Lac, Blazar, RS CVn, Radio Star, Nova and Nova-like star which are self-explanatory):

    object_type   meaning

    LMXB, BHC     Low-Mass X-Ray Binary, Black Hole candidate
    HMXB, BHC     High-Mass X-Ray Binary, Black Hole candidate
    LMXB, PSR     Low-Mass X-Ray Binary, Pulsar
    HMXB, PSR     High-Mass X-Ray Binary, Pulsar
    LMXB, NS      Low-Mass X-Ray Binary, Neutron Star
    HMXB, NS      High-Mass X-Ray Binary, Neutron Star
    AGN           Active Galactic Nucleus
    SNR           Supernova Remnant
    SNR, PSR      Supernova Remnant, Pulsar
    SY            Seyfert Galaxy
    DN            Dwarf Nova
    SGR           Soft Gamma Repeater
    QSR           Quasar
    UVS           Ultraviolet Source
    XRS           X-Ray Source
    CV            Cataclysmic Variable

Category
An assigned category (A, B, C, N or I) based on the significance of the detection before, and after (in parentheses), correction for systematic errors. The meaning of these categories is as follows (see Section 4 of the published paper for more details):

     A: Definite detection: Persistent sources in this category have an average
        flux over 9.1 years that exceeded a threshold of 0.01 photons cm^-2 s^-1
        in the 20 - 100 keV band. Transient sources in this category (indicated
        by having a value of category_flag of "t") exhibited at least one
        identifiable outburst with an average daily flux exceeding a threshold
        of 0.01 photons cm^-2 s^-1 in the 20 - 100 keV band.
     B: Definite detection: Sources with a 9.1-year average flux that exceeded
        10 sigma, but with average flux <0.01 photons cm^-2 s^-1 in the 20 - 100
        keV band.
     C: Possible detection: Sources with a 9.1-year average flux (20 - 100 keV)
        with a significance >= 3 sigma and < 10 sigma. Variability was not
        investigated; thus, transient activity was not considered and could
        be present in the BATSE dataset.
     N: Non-detection: Sources with a 9.1-year average flux (20 - 100 keV)
        with a significance between +/- 3 sigma. Transient activity from the
        sources was not considered and could be present in the BATSE dataset.
     I: Indeterminate: Sources with a 9.1-year average flux (20 - 100 keV)
        with a significance < -3 sigma, indicating confusion with nearby
        sources, or a poorly characterized systematic error in the surrounding
        sky region.

Category_Flag
This parameter is set to "t" for a category A source which is transient; i.e., the source exhibited at least one identifiable outburst with an average daily flux exceeding a threshold of 0.01 photons cm^-2 s^-1 in the 20 - 100 keV band, otherwise the source is considered persistent.

RA
The Right Ascension of the object. This was given in J2000 decimal degrees to a precision of 0.01 degrees in the originating table. Listed positions should be used for reference only. These positions were used in the analysis, and many are based on historical measurements and are often only accurate to within a few arcminutes. Location errors of a few arcminutes do not significantly affect flux measurements with the BATSE EOT.

Dec
The Declination of the object. This was given in J2000 decimal degrees to a precision of 0.01 degrees in the originating table. Listed positions should be used for reference only. These positions were used in the analysis, and many are based on historical measurements and are often only accurate to within a few arcminutes. Location errors of a few arcminutes do not significantly affect flux measurements with the BATSE EOT.

LII
The Galactic Longitude of the object.

BII
The Galactic Latitude of the object.

Significance_Ac
The detection significance for the 20 - 100 keV average photon flux averaged over the mission (9.1 years) after correction for systematic error.

Significance_Bc
The detection significance for the 20 - 100 keV average photon flux averaged over the mission (9.1 years) before correction for systematic error.

Flux_20to40
The flux of the source in the 20 - 40 keV energy band, in milliCrabs. The Crab relative fluxes, the authors found, are the most accurate method of displaying flux information for the deep sample in the absence of precise spectral fitting information for each source. Conversion factors from mCrab units to photon and energy fluxes are given in Appendix B, Table B2 of the published paper.

Flux_20to40_Error
The uncertainty in the 20 - 40keV energy band flux, in milliCrabs.

Flux_Flag
This parameter is set to "u" for cases where the uncorrected flux was very small relative to the systematic flux correction. In these cases, the uncorrected 4-band fluxes are reported because the authors believe they are closer to the true 9.1-year averages. See Section 2.4 of the published paper for more details.

Flux_40to70
The flux of the source in the 40 - 70 keV energy band, in milliCrabs. The Crab relative fluxes, the authors found, are the most accurate method of displaying flux information for the deep sample in the absence of precise spectral fitting information for each source. Conversion factors from mCrab units to photon and energy fluxes are given in Appendix B, Table B2 of the published paper.

Flux_40to70_Error
The uncertainty in the 40 - 70 keV energy band flux, in milliCrabs.

Flux_70to160
The flux of the source in the 70 - 160 keV energy band, in milliCrabs. The Crab relative fluxes, the authors found, are the most accurate method of displaying flux information for the deep sample in the absence of precise spectral fitting information for each source. Conversion factors from mCrab units to photon and energy fluxes are given in Appendix B, Table B2 of the published paper.

Flux_70to160_Error
The uncertainty in the 70 - 160 keV energy band flux, in milliCrabs.

Flux_160to430
The flux of the source in the 160 - 430 keV energy band, in milliCrabs. The Crab relative fluxes, the authors found, are the most accurate method of displaying flux information for the deep sample in the absence of precise spectral fitting information for each source. Conversion factors from mCrab units to photon and energy fluxes are given in Appendix B, Table B2 of the published paper.

Flux_160to430_Error
The uncertainty in the 160 - 430 keV energy band flux, in milliCrabs.

Class
The HEASARC Browse object classification, based on the value of the object_type parameter.

ObsID
The HEASARC data products identifier, used only to locate the appropriate data products for a given entry.

Contact Person

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

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:24:57 EDT