AT2FGLUS - Australia Telescope 2FGL Unassociated Sources Radio Source Catalog

Overview

The authors report results of the first phase of observations with the Australia Telescope Compact Array (ATCA) at 5 and 9 GHz of the fields around 411 gamma-ray sources having declinations less than +10 degrees which were detected by the Fermi Gamma-ray Space Telescope, but marked as unassociated in the 2nd Fermi Large-Area Telescope (2FGL) Catalog (available at the HEASARC as the FERMILPSC table). They have detected 424 radio sources with flux densities in the range from 2 mJy to 6 Jy in the fields of 283 gamma-ray sources within their gamma-ray position error ellipses (drawn to cover the area of 99 per cent probability of their localization). Of these, 146 objects were detected in both 5- and 9-GHz bands. The authors found 84 sources with spectral indices flatter than -0.5 in their sample. The majority of detected sources are weaker than 100 mJy and for this reason were not found in previous surveys. Approximately 1/3 of this sample, 128 objects, have the probability of being associated which is more than 10 times the probability of their being a background source found in the vicinity of the gamma-ray object by chance. This table contains the catalog of positions of these radio sources, estimates of their flux densities and their spectral indices, when available.

Catalog Bibcode

2013MNRAS.432.1294P

References

ATCA observations of Fermi unassociated sources
    Petrov L., Mahony E.K., Edwards P.G., Sadler E.M., Schinzel F.K.,
    McConnell D.
    <Mon. Not. R. Astron. Soc. 432, 1294 (2013)>
    =2013MNRAS.432.1294P

Provenance

This table was created by the HEASARC in July 2013 based on the electronic versions of Tables 1, 2 and 3 from the reference paper which were obtained from the MNRAS web site.

HEASARC Implementation

This HEASARC table contains the contents of three tables (1, 2 and 3) from the reference paper, viz., the 146 radio sources from Table 1 (objects detected at both 5- and 9-GHz within 2.7 arcminutes of the pointing direction), the 229 radio sources from Table 2 (objects detected in the 5-GHz sub-band only within 6.5 arcminutes of the pointing direction) and the 49 radio sources from Table 3 (48 objects detected at 5 GHz beyond 6.5 arcminutes from the 5-GHz pointing center and 1 object detected only at 9 GHz), for a grand total of 424 radio sources. The Table 3 sources were detected at large offsets from the pointing directions where the calibration for beam attenuation becomes uncertain and hence no 5 or 9 GHz flux densities are given for these sources: the authors estimate that the flux densities of these sources are likely at least 20 mJy (presumably at 5 GHz).

To allow users to select these 3 sub-samples more easily from this HEASARC table, the HEASARC has created a new parameter called source_sample which is set to 1 for radio sources from Table 1, 2 for Table 2 sources and 3 for Table 3 sources.

Parameters

TwoFGL_Name
The (truncated) 2FGL designation of the gamma-ray source. The full 2FGL source name can have a letter suffix, either 'c' or 'e', e.g., '2FGL 0534.9-0450c', but these suffixes have been omitted from the 2FGL names in this table: thus, for example, this source is labeled '2FGL 0534.9-0450' herein.

Name
The IAU-style J2000.0 position-based designation of the radio source,. The HEASARC has added the prefix '[PME2013]' (for Petrov, Mahony, Edwards 2013) to these names in accordance with the recommendations of the Dictionary of Nomenclature of Celestial Objects, e.g., '[PME2013] J0014-0512'. There are 14 cases where this naming scheme would result in two radio sources being given the same name: to avoid this, the authors have replaced the final digit of the declination for one of the pair with the letter 'A'.

Source_Flags
This flag parameter can have the following (non-blank) values:

       a = source is high confidence: it has likelihood ratio greater than 10
       e = source was found in a field of extended objects
       f = source has spectral index flatter (>) than -0.5 between 5 and 9 GHz

RA
The Right Ascension of the radio source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.01 seconds of time in the original table(s).

Dec
The Declination of the radio source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 arcseconds in the original table(s).

LII
The Galactic Longitude of the radio source.

BII
The Galactic Latitude of the radio source.

RA_Error
The 1-sigma uncertainty in the Right Ascension of the radio source, in arcseconds.

Dec_Error
The 1-sigma uncertainty in the Declination of the radio source, in arcseconds.

Flux_5_GHz
The flux density of the radio source at 5 GHz, in mJy, corrected for beam attenuation. This is not given for the Table 3 sources (the sources with source_sample = 3) which were detected beyond 6.5 arcminutes from the pointing direction: the authors estimate that the flux densities of these sources are likely at least 20 mJy.

Flux_5_GHz_Error
The standard deviation in the flux density of the radio source at 5 GHz, in mJy,

Flux_9_GHz
The flux density of the radio source at 9 GHz, in mJy, corrected for beam attenuation. This is only given for the 146 sources listed in Table 1 of the reference paper (the sources with source_sample = 1).

Flux_9_GHz_Error
The standard deviation in the flux density of the radio source at 9 GHz, in mJy,

Spectral_Index_5
The spectral index (alpha) of the radio source within the 5-GHz sub-band, viz., between 4.58 and 6.42 GHz, where the flux density S_nu ~ nu^alpha. Spectral index estimates with uncertainties > 0.4 are omitted.

Spectral_Index_5_Error
The standard deviation in the spectral index of the radio source within the 5-GHz sub-band.

Spectral_Index_9
The spectral index (alpha) of the radio source within the 9-GHz sub-band, viz., between 8.09 and 9.92 GHz, where the flux density S_nu ~ nu^alpha. Spectral index estimates with uncertainties > 0.4 are omitted.

Spectral_Index_9_Error
The standard deviation in the spectral index of the radio source within the 9-GHz sub-band.

Spectral_Index_59
The spectral index (alpha) of the radio source between 5 and 9 GHz, where the flux density S_nu_~ nu^alpha, for those sources which were detected in both sub-bands. Spectral index estimates with uncertainties > 0.4 are omitted.

Spectral_Index_59_Error
The standard deviation in the spectral index of the radio source between 5 and 9 GHz.

Offset
The angular distance between that of the 2FGL gamma-ray source (also the nominal ATCA pointing direction) and the radio source, in arcminutes.

Norm_Offset
The angular distance between that of the 2FGL gamma-ray source (also the nominal ATCA pointing direction) and the radio source divided by the standard deviation of the 2FGL position localization.

Flux_1_GHz
If the radio source is associated with an object from either the NVSS, SUMSS or MGPS-2 catalogs, its flux density at 1.4 GHz (NVSS) or 0.843 GHz (SUMSS and MGPS-2) is given, in mJy.

Alt_Name
If the radio source is associated with an object from either the NVSS, SUMSS or MGPS-2 catalogs, the name of the associated source.

WISE_Name
If the radio source is associated with an object from the WISE catalog, the name of the associated WISE source.

Source_Sample
To allow users to select the 3 sub-samples contained in this HEASARC table more easily, the HEASARC has created this parameter, which is set to 1 for radio sources from Table 1 of the reference paper, 2 for Table 2 sources, and 3 for Table 3 sources.

Contact Person

Questions regarding the AT2FGLUS database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: Wednesday, 10-Jul-2013 12:40:24 EDT