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MGGAMMADET - Gamma-Ray Source Detailed Catalog (Macomb & Gehrels 1999)

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Overview

This database table contains the slightly revised contents of the detailed Tables 2A - 2G from the General Gamma-Ray Source Catalog of Macomb & Gehrels (1999). It lists details of all known gamma-ray observations within the energy range from 50 keV to ~1 TeV for 314 discrete gamma-ray sources that were listed in Tables 2A - 2G of the published version of this catalog, including all 310 sources listed in the published Suumary Table 1, together with 4 sources (2CG 054+01, A0620-00, GX 340+0, and H1822-000) that were listed only in Table 2 of the published catalog but were (presumably accidentally) omitted from Table 1. The positions for the sources in the present database were taken from Table 1 of the General Gamma-Ray Source Catalog.

Thus, this table is essentially a compilation of gamma-ray observations of discrete sources as known to the authors as of early 1999. There is another HEASARC database table called the Gamma-Ray Source Summary Catalog (Macomb & Gehrels 1999) or MGGAMMACAT that contains the summary information on these sources that was given in Table 1 of the General Gamma-Ray Source Catalog.

As noted above, this is a slightly revised version compared to the published Tables 2A - 2G. The known differences between the HEASARC and published versions are discussed in the HEASARC_Version section of the help documentation.


Catalog Bibcode

1999ApJS..120..335M

References

General Gamma-Ray Source Catalog of Macomb & Gehrels 1999, ApJS, 120, 335.

Provenance

This data table was created by the HEASARC in March 2002 based upon machine-readable versions of Tables 2A-2G of the Macomb & Gehrels (1999) General Gamma-Ray Source Catalog that were supplied by the authors.

HEASARC Version

This is a slightly revised version compared to the published Tables 2A - 2G of the published catalog. The known differences between the HEASARC and published versions are:

(i) Some values of the energy, flux, and other parameters have been rounded and/or truncated in the HEASARC version compared to the published version.

(ii) the class parameter values were created by the HEASARC based on the source type parameter value given in Table 1 of the published catalog, except that more specific classes have been given for many of the X-ray binary sources in this catalog. These latter were obtained using the classes for these sources that are given in the HEASARC X-ray Binary database tables XRBCAT and HMXBCAT.

(iii) The alphabetic footnote values and the numeric reference code (ref_code) values in the published tables 2A, 2B, ... 2G were specific to each separate table, and thus general schemes had to be devised for each of these parameters in the current table, since the latter is based on a union of the published tables 2A - 2G.


Parameters

Name
A commonly used designation for the gamma-ray source. Notice that alternative sources are provided in the related MGGAMMACAT table.

RA
The Right Ascension of the gamma-ray source. This was given in J2000 coordinates in decimal degrees to a precision of 0.01 degrees in the original published Table 1.

Dec
The Declination of the gamma-ray source. This was given in J2000 coordinates in decimal degrees to a precision of 0.01 degrees in the original published Table 1.

LII
The Galactic Longitude of the gamma-ray source.

BII
The Galactic Latitude of the gamma-ray source.

Instrument
The name of the gamma-ray instrument used in the selected observation. Brief descriptions and references for all of the gamma-ray instruments are given in Table 4 of the published catalog.

Low_Energy
The lower limit to the energy range for the selected observation, E1, in MeV. E1 is the lowest energy for which the object was detected and often related to the lower energy limit of the detector. In the case of most line detections, it is the centroid energy of the line detection. Note that the requirements for inclusion in this catalog generally imply that the minimum energy of an observation must be less than ~1 TeV.

High_Energy
The maximum energy of the selected observation, E2, in MeV. In many cases, E2 will be the energy limit of the detector itself, but in those cases in which the observation spans only a portion of the available energy range, E2 represents the highest detectable energy. This parameter is not used in the case of a line detection. Note that the requirements for inclusion in this catalog generally imply that the maximum energy of an observation must be greater than 50 keV. In cases in which a minimum energy is reported in the reference but no upper energy, and no information from the paper implies a maximum detection energy aside from the intrinsic detector limit, the value of the maximum energy is left blank.

Flux_Data
The photon flux data in more-or-less the form it was given in the published catalog (see also the photon_flux, photon_flux_limit, photon_flux_error, photon_flux_flag, and photon_flux_band parameters). It is the total emission over the energy band delimited by the low_energy E1 and high_energy E2 parameters, or the line strength. The flux may also be an upper limit, as indicated by a less than sign '<'. Part of the philosophy of this catalog is that upper limits are often as important as detections. The authors therefore included as many published upper limits as was possible. If the listed flux values do not exactly match the bounds of E1 and E2, the appropriate energy range (in MeV) is also quoted in parentheses. An interested party can then use any available spectral information to extrapolate to the larger energy range. The notes in Table 3 in the published catalog can also be consulted for more information on the spectral and flux information for each observation. The units for each entry are usually photons cm^-2 s^-1, although some nonstandard units are included: such cases are flagged by the presence of an alphabetic character 'f', 'g', or 'h', in this field, corresponding to an equivalent footnote to the entry in the published table. For instance, some observations with an 'f' character in this field give the intensity at one point in the spectrum, and therefore the units include a per keV (keV^-1), other observations with a 'g' character in this field give the flux in units of erg cm^-2 s^-1, while observations with a 'h' character in this field give the luminosity in 10^38 erg s^-1 for an assumed distance of 63 kpc. For more information about the meaning of the other flag values, see the help entry for the photon_flux_flag parameter.

Photon_Flux_Limit
The HEASARC has parsed the complex information given in the Flux column of Tables 2A - 2G of the published catalog, and reproduced in the flux_data parameter in the current table, so as to make it more easily searchable in a database table. This parameter is a flag that is set to '<' to indicate that the observed photon flux was an upper limit, not a detection.

Photon_Flux
The HEASARC has parsed the complex information given in the Flux column of Tables 2A - 2G of the published catalog, and reproduced in the flux_data parameter in the current table, so as to make it more easily searchable in a database table. This parameter is the photon flux, i.e., the total emission over the energy band delimited by the low_energy E1 and high_energy E2 parameters, or (in some small number of cases) the line strength. The flux may also be an upper limit, as indicated by the value of the photon_flux_limit parameter for the entry being '<'. The notes in Table 3 in the published catalog can also be consulted for more information on the spectral and flux information for each observation. The units for each entry are usually photons cm^-2 s^-1, although some cases with nonstandard units are included: such cases are flagged by the presence of an alphabetic character 'f', 'g', or 'h', in this field, corresponding to an equivalent footnote to the entry in the published table. For instance, some observations with an 'f' character in this field give the intensity at one point in the spectrum, and therefore the units include a per keV (keV^-1), other observations with a 'g' character in this field give the flux in units of erg cm^-2 s^-1, while observations with a 'h' character in this field give the luminosity in 10^38 erg s^-1 for an assumed distance of 63 kpc.

Photon_Flux_Error
The HEASARC has parsed the complex information given in the Flux column of Tables 2A - 2G of the published catalog, and reproduced in the flux_data parameter in the current table, so as to make it more easily searchable in a database table. This parameter is the error in the photon flux for the selected observation. The units for each entry are usually photons cm^-2 s^-1, although some cases with nonstandard units are included: such cases are flagged by the presence of an alphabetic character 'f', 'g', or 'h', in this field, corresponding to an equivalent footnote to the entry in the published table. For instance, some observations with an 'f' character in this field give the intensity at one point in the spectrum, and therefore the units include a per keV (keV^-1), other observations with a 'g' character in this field give the flux in units of erg cm^-2 s^-1, while observations with a 'h' character in this field give the luminosity in 10^38 erg s^-1 for an assumed distance of 63 kpc.

Photon_Flux_Flag
The HEASARC has parsed the complex information given in the Flux column of Tables 2A - 2G of the published catalog, and reproduced in the flux_data parameter in the current table, so as to make it more easily searchable in a database table. This parameter is a flag for the photon_flux. Alphabetic footnote values and the numeric reference code (ref_code) values in the published tables 2A, 2B, ... 2G were specific to each separate table, and thus a general schemes had to be devised by the HEASARC for these parameters in the current table, based as it is on a union of the published tables 2A - 2G. The key to the flag values as used in this HEASARC version is as follows:

    Value        Meaning

     b       Photon flux calculated from energy flux based upon assumed power
             law with stated spectral index or index 2.0
     c       Flux calculated from spectral fit; error reflects error in fit
             coefficient only
     d       Flux estimated from graph or plot
     e       Flux upper limit calculated or estimated from error on a very weak
             detection
     f       These observations give the intensity at one point in the spectrum;
             the units are photons cm^-2 s^-1 keV^-1
     g       In erg cm^-2 s^-1
     h       In 10^38 ergs s^-1 for a distance of 63 kpc
     i       Per steradian
     j       Total
     k       Pulsed
     l       Total - Pulsed
  

A handful of entries have upper-case, non-superscripted letters in the flux column of Table 2 in the published paper, the meaning of which is unknown, viz. the SIGMA observation of Cen A has an 'A' in this field, the MISO observation of 2CG 135+01 has a 'D' in this field, and the SIGMA observation of GRO J1719-24 and the Tata XMPC observation of H1907+097 each have an 'E' in this field.

Photon_Flux_Band
The HEASARC has parsed the complex information given in the Flux column of Tables 2A - 2G of the published catalog, and reproduced in the flux_data parameter in the current table, so as to make it more easily searchable in a database table. This parameter is the energy range in which the quoted photon flux was measured for those cases where it does not exactly match the values specified by the low_energy and high_energy parameters, E1 and E2. Combining this information with any available spectral information on the selected source would enable one to extrapolate to any desired energy range.

Normalization
This parameter is one of four (normalization, spectral_index, ref_energy and break_energy) that contain spectral information about the gamma-ray source derived from the particular observation. It is the normalization constant for whatever spectral form was used. It is usually in units of cm^-2 s^-1 MeV^-1.

Spectral_Index
This parameter is one of four (normalization, spectral_index, ref_energy and break_energy) that contain spectral information about the gamma-ray source derived from the particular observation. It is the parameter that describes the shape of the spectral form used, i.e., the power-law index or the temperature. The value given is the power-law spectral index, unless the value of the parameter spectral_index_flag is 'a', in which cases the value given is a temperature, and the units are keV. For cases with broken power-law fits, the second spectral index appears in parentheses. Some of the pulsar entries include fits for total and pulsed emission or unpulsed and pulsed emission, as indicated by the value of the photon_flux_flag parameter being 'j', 'k', or 'l'.

Spectral_Index_Flag
This is a flag parameter whose value is set to 'a' to indicate that the quoted value for the spectral index is the temperature in keV, rather than the usual power-law spectral index.

Ref_Energy
This parameter is one of four (normalization, spectral_index, ref_energy and break_energy) that contain spectral information about the gamma-ray source derived from the particular observation. It is the reference energy for the spectral fit, in MeV, i.e., it is usually the energy at which the quoted normalization value is the flux.

Break_Energy
This parameter is one of four (normalization, spectral_index, ref_energy and break_energy) that contain spectral information about the gamma-ray source derived from the particular observation. It is the break energy for cases with a broken power-law spectral fit, in MeV.

Date_Range
The calendar dates of the relevant observation. Most observations which were spread over many epochs are not listed in detail; instead, the start of the first and the end of the last observation are given. In addition, the date range of long or monitoring observations will sometimes be given in terms of months or even years.

Ref_Code
A numeric reference code for the paper or papers whose results are described in the entry. Users are encouraged by the catalog authors to go back to the original reference(s) for more detailed and specific information. The numeric reference code values in the published tables 2A, 2B, ... 2G were specific to each separate table, and thus a general scheme had to be devised by the HEASARC for this parameter in the current table, since it is based on a union of the published tables 2A - 2G, which simply involved using the table letter prefix as a prefix for the ref_code: thus, for example, a value of 'A: 5' means that the original reference was no. 5 in Table 2A. The key to the codes can be found in the footnotes to the Tables 2A - 2G in the the published catalog (q.v.).

Class
The HEASARC Browse object classification for the source. These class parameter values were created by the HEASARC based on the values of the source type parameter given in Table 1 of the published catalog, except that more specific classes have been given for many of the X-ray binary sources in this catalog. These latter were obtained using the classes for these sources that are given in the HEASARC X-ray Binary database tables XRBCAT and HMXBCAT.


Contact Person

Questions regarding the MGGAMMADET database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 8-Nov-2004