Browse
this table...

SWXRT1FGL - Swift XRT Counterparts to Unidentified 1FGL Sources

HEASARC
Archive

Overview

The authors have analyzed all the archival X-ray data of 134 unidentified (unID) gamma-ray sources listed in the first Fermi/LAT (1FGL) catalog and subsequently followed up by the Swift/XRT. They constructed the spectral energy distributions (SEDs) from radio to gamma-rays for each X-ray source detected, and tried to pick up unique objects that display anomalous spectral signatures. In these analyses, they target all the 1FGL unID sources, using updated data from the second Fermi/LAT (2FGL) catalog on the Large Area Telescope (LAT) position and spectra. In the reference paper, the authors discuss the X-ray identification results and the SEDs of all 134 sources observed with the Swift/XRT.

The selection criteria for the Fermi sources were as follows: (1) categorized as unID sources in the 1FGL catalog, (2) localized at high Galactic latitude |b| > 10 degrees, (3) observational data were made public by October 2011, and (4) the positional center of the Swift FoV is within 12 arcminutes of the 1FGL sources. Among 630 unID sources listed in the 1FGL catalog, this selection yielded 134 sources which were analyzed in this study.

This table contains the list of the positions and 0.3-10 keV count rates of 267 Swift XRT sources which were detected with a signal-to-noise ratio (SNR) of 3 or more within the Swift/XRT field of views (FoV) of 112 of the 134 1FGL unID gamma-ray sources, with 22 of the 1FGL sources having no detected Swift XRT sources in their FoVs. The Swift XRT images of all 134 unID gamma-ray sources, the positions of the significant XRT sources, and the 95% 1FGL and 2FGL error ellipses are shown in Figure 11 of the reference paper.


Catalog Bibcode

2013ApJS..208...25T

References

 Multiband Diagnostics of Unidentified 1FGL Sources with Suzaku and Swift
X-ray Observations
     Takeuchi Y., Kataoka J., Maeda K., Takahashi Y., Nakamori T., Tahara M.
    <Astrophys. J.Suppl. 208, 25 (2013)>
    =2013ApJS..208...25T

Provenance

This table was created by the HEASARC in September 2014 based on an electronic version of Table 4 from the reference paper which was obtained from the ApJS website.

Parameters

Name
The Swift XRT source designation for an X-ray source in the FoV of a follow-up Swift XRT observation of the Fermi gamma-ray source. This was created by the HEASARC using the X-ray source coordinates in the style recommended by the CDS Dictionary of Nomenclature of Celestial Objects for such sources. To verify whether or not the X-ray source was in the 95% error ellipse of the 1FGL source (or its 2FGL counterpart), the user is referred to Figure 11 of the reference paper.

Fermi_1FGL_Name
The 1FGL gamma-ray source designation.

XRT_Source_Number
The XRT source number within the FoV of the specified 1FGL gamma-ray source.

RA
The Right Ascension of the Swift XRT source in the selected equinox. This was given in J2000 decimal degree coordinates to an accuracy of 10-4 degrees (0.36 arcseconds) in the original table.

Dec
The Declination of the Swift XRT source in the selected equinox. This was given in J2000 decimal degree coordinates to an accuracy of 10-4 degrees (0.36 arcseconds) in the original table.

LII
The Galactic Longitude of the Swift XRT source.

BII
The Galactic Latitude of the Swift XRT source.

Error_Radius
The radius of the 90% confidence error circle of the Swift XRT source, in arcseconds.

Count_Rate
The count rate of the Swift XRT X-ray source, in the 0.3-10 keV band, in ct/s.

Count_Rate_Error
The uncertainty in the count rate of the Swift XRT X-ray source, in the 0.3-10 keV band, in ct/s.

SNR
The signal-to-noise ratio of the Swift XRT X-ray source, in the 0.3-10 keV band.


Contact Person

Questions regarding the SWXRT1FGL database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 26-Sep-2014