GPSR5 - Galactic Plane 5-GHz Very Large Array Survey

Overview

This table contains the sources from the Galactic Plane 5-GHz Very Large Array (VLA) Survey, or GPSR5, in which the authors used the VLA to survey the inner Galaxy (|b| < 0.4 degrees, l = 350 - 40 degrees) at 5 GHz to a limiting sensitivity of between 2.5 and 10 mJy. The survey resulted in a catalog of 1272 discrete sources (including 100 sources which lie outside the formal survey area) of which they tentatively identified ~450 as ultracompact H II regions and ~45 as planetary nebulae. Approximately 30% of the radio sources were detected in the IRAS Point Source Catalog. The results confirm a scale height of only 30 pc for ultracompact H II regions. They also show that source lists which are generated from the IRAS Point Source Catalog alone suffer serious selection effects; the combination of the IRAS and radio surveys allows the production of a much more complete census of the regions of massive star formation in our Galaxy.

Notice that 5-GHz sources for which there were more than 1 matching entry at 1.4 GHz are listed multiple times, once for each 1.4-GHz source, hence the number of entries is 1355 although there are only 1272 unique sources.

Catalog Bibcode

1994ApJS...91..347B

References

A 5GHz VLA survey of the galactic plane.
       Becker R.H., White R.L., Helfand D.J., Zoonematkermani S.
      <Astrophys. J. Suppl. Ser. 91, 347 (1994)>
      =1994ApJS...91..347B

Provenance

This table was created by the HEASARC in May 2005 based on CDS table J/ApJS/91/347/table2.dat .

HEASARC Implementation

The HEASARC has added two parameters which were not present in either the published version of this catalog or in the CDS table from which this Browse table was created so as to make some of its features clearer to users: (i) As noted above, 5-GHz sources for which there were more than 1 matching entry at 1.4 GHz (and have values of the multiple_flag parameter set to 'Y') are listed multiple times, once for each 1.4-GHz source, hence the number of entries is 1355 although there are only 1272 unique sources. The HEASARC has added a parameter called ctrpart_number which is set to 1 for the first entry of a given 5-GHz source, 2 for the second, and so on; (ii) According to the published paper, entries for which the only information at 1.4 GHz is the peak 1.4-GHz flux density (flux_21_cm) are actually not detections but are implicit upper limits. The HEASARC has added a new parameter limit_flux_21_cm which is set to '<' in such cases, so as to make these upper limits explicit.

Parameters

Name
The name of the radio source, using a nomenclature based on the Galactic coordinates of the source. If the source was detected at 5 GHz, then the name given is of the form 'GPSR5 LLL.lll+B.bbb', where the prefix stands for Galactic Plane Survey Radio-source at 5 GHz. If the source was only detected at 21 GHz, the name given is that for the 21-GHz source catalog, namely, it is of the form 'GPSR LLL.lll+B.bbb', where the prefix stands for Galactic Plane Survey Radio-source at 1.4 GHz.

RA
The Right Ascension of the radio source in the selected equinox. If the source was detected at 5 GHz, then this corresponds to the position of the 5-GHz source, while, if the source was only detected at 21 GHz, it is that of the 21-GHz source (presumably). The RA was given in B1950 coordinates and to a precision of 0.01 seconds of time in the original table.

Dec
The Declination of the radio source in the selected equinox. If the source was detected at 5 GHz, then this corresponds to the position of the 5-GHz source, while, if the source was only detected at 21 GHz, it is that of the 21-GHz source (presumably). The Declination was given in B1950 coordinates and to a precision of 0.1 arcseconds in the original table.

LII
The Galactic Longitude of the radio source

BII
The Galactic Latitude of the radio source

Limit_Flux_6_cm
This parameter is set to '<' if the quoted peak 5-GHz flux density (flux_6_cm) is an upper limit rather than a detection.

Flux_6_cm
The peak flux density at 5 GHz (6 cm), in milliJanskies (mJy/beam, strictly speaking), corrected for the primary beam response, i.e., the loss of sensitivity of the primary beam of the antennas at locations far away from the field centre.

Limit_Int_Flux_6_cm
This parameter is set to '<' if the quoted integrated 5-GHz flux density (int_flux_6_cm) is an upper limit rather than a detection.

Int_Flux_6_cm
The integrated flux density at 5 GHz (6 cm), in mJy, corrcted for the primary beam response, i.e., the loss of sensitivity of the primary beam of the antennas at locations far away from the field centre.

Src_Diameter_6_cm
The source diameter at 5 GHz, in arcseconds. The quoted diameter is the mean of the best-fit full-width half-maximum (FWHM) of the major and minor axes of the source as determined by a Gaussian fit.

Flux_6_cm_Flag
If a 5-GHz source was observed in the CnD configuration, this parameter is set to the value of 'CD' to indicate that the interpretation of the size is different because of the poorer resolution.

Alt_Name
The 1.4 GHz name of the source, if it was detected at this frequency, in the form 'GPSR LLL.lll+B.bbb', where the prefix stands for Galactic Plane Survey Radio-source at 1.4 GHz.

New_Source_Flag
A few 1.4-GHz sources were new to this catalog, i.e., were not listed in Papers I - V which presented the results of the 1.4-GHz Galactic Plane Survey: in such cases, the value of this parameter is set to 'N' for new.

Flux_21_cm
The peak flux density at 1.4 GHz (21 cm), in milliJanskies (mJy/beam, strictly speaking), corrected for the primary beam response, i.e., the loss of sensitivity of the primary beam of the antennas at locations far away from the field centre.

Int_Flux_21_cm
The integrated flux density at 1.4 GHz (21 cm), in mJy, corrcted for the primary beam response, i.e., the loss of sensitivity of the primary beam of the antennas at locations far away from the field centre.

Int_Flux_21_cm_Flag
This parameter is set to '+' if the flux was measured using IMEAN as described in Paper I (Zoonematkermani et al. 1990).

Src_Diameter_21_cm
The source diameter at 1.4 GHz, in arcseconds. The quoted diameter is the mean of the best-fit full-width half-maximum (FWHM) of the major and minor axes of the source as determined by a Gaussian fit.

Limit_Flux_21_cm
According to the published paper, entries for which the only information at 1.4 GHz is the 1.4-GHz flux density (flux_21_cm) are actually not detections but are implicit upper limits. The HEASARC has added this parameter, which is set to '<' in such cases, so as to make these upper limits explicit.

Multiple_Flag
There are a number of 5-GHz sources for which there were more than 1 matching entry at 1.4 GHz. For these entries, the value of the multiple_flag parameter has been set to 'Y' (in this HEASARC table, as opposed to '"' in the published and CDS versions). Notice that these 5-GHz sources are listed multiple times in this table, once for each 1.4-GHz source counterpart. The HEASARC has also added a new parameter called ctrpart_number which is set to 1 for the first entry of a given 5-GHz source, 2 for the second, and so on.

Ctrpart_Number
In this table, 5-GHz sources for which there were more than 1 matching entry at 1.4 GHz are listed multiple times, once for each 1.4-GHz source, and hence the number of entries is 1355 compared to the number of unique sources, which is 1272. The HEASARC has created this parameter in order to make this feature of the table more evident: it is set to 1 for the first 21-GHz source entry corresponding to a given 5-GHz source, 2 for the second, and so on.

Comments
This parameter contains comments about the radio source, such as coincidences with objects in other catalogs, using the following nomenclature:

               I: Has a likely counterpart in the IRAS PSC
               i: Has a low probability IRAS PSC match
               G: Source is part of a group, integrated flux includes another
                  nearby source (also marked with G)
     MLNSO(name): Master List of Non-Stellar Objects
          PN l+b: Strasbourg Catalog of Planetary Nebulae (Cat. <V/84>)
             SNR: Associated with a supernova remnant
       SNR?, PN?: May be either PN or a SNR
          TX=fff: Texas 0.365 GHz (Cat. <VIII/42>) source, fff = flux in mJy
              XR: X-ray source in Einstein IPC catalog
         int=xxx: Large extended source, xxx = integrated flux in mJy

Contact Person

Questions regarding the GPSR5 database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: Tuesday, 06-Mar-2007 16:04:57 EST