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FERMILATRA - Fermi LAT Sources Refined Associations Catalog

HEASARC
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Overview

The Fermi-Large Area Telescope (LAT) First Source Catalog (1FGL: Abdo et al. 2010, ApJS, 188, 405) was released in 2010 February and the Fermi-LAT 2-Year Source Catalog (2FGL: Nolan et al. 2012, ApJS, 199, 31) appeared in 2012 April, based on data from 24 months of operations. Since they were released, many follow up observations of unidentified gamma-ray sources have been performed and new procedures for associating gamma-ray sources with potential counterparts at other wavelengths have been developed. In the reference paper, the authors review and characterize all of the associations as published in the 1FGL and 2FGL catalogs on the basis of multi-frequency archival observations. In particular, they locate 177 spectra for the low-energy counterparts that were not listed in the previous Fermi catalogs, and in addition they present new spectroscopic observations of eight gamma-ray blazar candidates. Based on their investigations, the authors introduce a new counterpart category of "candidate associations" and propose a refined classification for the candidate low-energy counterparts of the Fermi sources. They compare the 1FGL-assigned counterparts with those listed in 2FGL to determine which unassociated sources became associated in later releases of the Fermi catalogs. The authors also search for potential counterparts to all of the remaining unassociated Fermi sources. Finally, they prepare a refined and merged list of all of the associations of 1FGL plus 2FGL that includes 2219 unique Fermi objects. This is the most comprehensive and systematic study of all the associations collected for the gamma-ray sources available to the date of this study. The authors conclude that 80% of the Fermi sources have at least one known plausible gamma-ray emitter within their positional uncertainty regions.

Catalog Bibcode

2015ApJS..217....2M

References

Refining the associations of the Fermi Large Area Telescope source catalogs.
    Massaro F., D'Abrusco R., Landoni M., Paggi A., Masetti N., Giroletti M.,
    Oti-Floranes H., Chavushyan V., Jimenez-Bailon E., Patino-Alvarez V.,
    Digel S.W., Smith H.A., Tosti G.
   <Astrophys. J. Suppl. Ser., 217, 2 (2015)>
   =2015ApJS..217....2M    (SIMBAD/NED BibCode)

Provenance

This table was created by the HEASARC in May 2015 based on CDS Catalog J/ApJS/217/2 file table4.dat.

Parameters

Name
The source designation adopted by the HEASARC. The 1FHL name is used, if one is available, else the 2FGL name. If there is no 2FGL name available, the 1FGL name is adopted.

RA
The Right Ascension in the selected equinox of the gamma-ray source in the catalog to which its name refers. This parameter was not present in the original table but was added by the HEASARC to enable position-based searches.

Dec
The Declination in the selected equinox of the gamma-ray source in the catalog to which its name refers. This parameter was not present in the original table but was added by the HEASARC to enable position-based searches.

LII
The Galactic Longitude of the gamma-ray source. This parameter was not present in the original table but was added by the HEASARC to enable position-based searches

BII
The Galactic Latitude of the gamma-ray source. This parameter was not present in the original table but was added by the HEASARC to enable position-based searches

Fermi_1FGL_Name
The 1FGL (Abdo et al. 2010, ApJS, 188, 405) designation of the gamma-ray source in the style recommended by the Dictionary of Nomenclature of Celestial Objects, viz., '1FGL JHHMM.m+DDMM'.

Fermi_2FGL_Name
The 2FGL (Nolan et al. 2012, ApJS, 199, 31) designation of the gamma-ray source in the style recommended by the Dictionary of Nomenclature of Celestial Objects, viz., '2FGL JHHMM.m+DDMM'.

Fermi_1FHL_Name
The 1FHL (Ackermann et al. 2013, ApJS, 209, 34) designation of the gamma-ray source in the style recommended by the Dictionary of Nomenclature of Celestial Objects, viz., '1FHL JHHMM.m+DDMM)'.

Source_Category
The gamma-ray source category, coded as follows:

      I = identified;
      A = associated;
      C = candidate;
      U = unidentified.
  
See section 2 of the reference paper for more details.

Ctrpart_1_Name
The name of the first proposed low-energy counterpart to the gamma-ray source.

Notes_Ctrpart_1
Multi-frequency notes for the first proposed low-energy counterpart to the gamma-ray source. The symbols used for the multi-frequency notes are reported in Section 5 (Table 3) of the reference paper as (where PSR means known pulsar):

    Symbol  Comment

    b       PSR in a binary system
    e       PSR detected in {gamma} rays by the Compton gamma-ray Observatory
    g       PSR discovered in LAT gamma-ray data
    m       MSP (millisecond pulsar)
    p       Pulsar discovered by the Pulsar Search Consortium (PSC)
    r       PSR discovered in the radio
    u       PSR discovered using a Fermi-LAT seed position
    x       PSR discovered in X-rays
  
For the references for the optical spectra whose truncated versions are given in this parameter field, see the refs.dat file at ftp://cdsarc.u-strasbg.fr/pub/cats/J/ApJS/217/2/refs.dat.

Ctrpart_1_Redshift
A redshift estimate for the first proposed low-energy counterpart to the gamma-ray source, if the source i extragalactic.

Ctrpart_1_Redshift_Flag
A flag parameter for the corresponding redshift estimate that is set to '?' if the estimate is uncertain. One source ('2FGL J1231.6+1417') has a value of 'el' for this parameter: the meaning of this is not given in the documentation.

Ctrpart_1_Inside_Notes
A flag parameter containing spatial notes if the first low-energy counterpart lies inside a star-forming region (SFR), supernova remnant (SNR), or pulsar wind nebula (PWN).

Ctrpart_1_Include_Notes
A flag parameter containing spatial notes if the first low-energy counterpart includes within it a known pulsar (PSR) or millisecond pulsar (MSP).

Ctrpart_1_Source_Type
The source class for the first proposed low-energy counterpart to the gamma-ray source (see Section 4 of the reference paper for the details). The classification codes are as follows:

    unc = Unclassified sources (411 sources + 8 in sfr)
    ugs = Unidentified {gamma}-ray source (394 sources)
    bzq = Quasar radio loud with flat radio spectrum (351 sources)
    bzb = BL Lac object (297 sources)
    bzu = Blazar of uncertain type (57 sources)
    bcn = Blazar candidate (286 sources)
    sfr = Star-forming-HII region (90 sources)
    psr = Pulsar (88 sources + 23 in pulsar wind nebula (pwn) and 7 in snr)
    msp = Millisecond pulsar (51 sources)
    snr = Supernova remnant (79 sources + 12 with psr)
    gal = Normal galaxy (11 sources)
    rdg = Radio galaxy (10 sources)
    sbg = Starburst galaxy (3 sources)
    sey = Seyfert galaxy (3 sources)
    glc = Globular cluster (10 sources + 1 in sfr and 1 with psr)
    pwn = Pulsar wind nebula (6 sources + 6 with psr)
    hmb = High mass X-ray binary (2 sources + 3 in sfr)
    bin = Binary star (1 source)
  

Ctrpart_1_RA
The Right Ascension of the first proposed low-energy counterpart to the gamma-ray 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.

Ctrpart_1_Dec
The Declination of of the first proposed low-energy counterpart to the gamma-ray source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.01 arcseconds in the original table.

Ctrpart_1_Bmag
The B magnitude for the first low-energy counterpart to the gamma-ray source taken from the USNO-B1 Catalog (Monet et al. 2003, AJ, 125, 984), only for the blazar candidates (bcn) and the unclassified (unc) sources.

Ctrpart_1_Rmag
The R magnitude for the first low-energy counterpart to the gamma-ray source taken from the USNO-B1 Catalog (Monet et al. 2003, AJ, 125, 984), only for the blazar candidates (bcn) and the unclassified (unc) sources.

Ctrpart_2_Name
The name of the second proposed low-energy counterpart to the gamma-ray source.

Notes_Ctrpart_2
Multi-frequency notes for the second proposed low-energy counterpart to the gamma-ray source. The symbols used for the multi-frequency notes are reported in Section 5 (Table 3) of the reference paper as (where PSR means known pulsar):

    Symbol  Comment

    b       PSR in a binary system
    e       PSR detected in {gamma} rays by the Compton gamma-ray Observatory
    g       PSR discovered in LAT gamma-ray data
    m       MSP (millisecond pulsar)
    p       Pulsar discovered by the Pulsar Search Consortium (PSC)
    r       PSR discovered in the radio
    u       PSR discovered using a Fermi-LAT seed position
    x       PSR discovered in X-rays
  
For the references for the optical spectra whose truncated versions are given in this parameter field, see the refs.dat file at ftp://cdsarc.u-strasbg.fr/pub/cats/J/ApJS/217/2/refs.dat.

Ctrpart_2_Source_Type
The source class for the second proposed low-energy counterpart to the gamma-ray source (see Section 4 of the reference paper for the details). The classification codes are as follows:

    unc = Unclassified sources (411 sources + 8 in sfr)
    ugs = Unidentified {gamma}-ray source (394 sources)
    bzq = Quasar radio loud with flat radio spectrum (351 sources)
    bzb = BL Lac object (297 sources)
    bzu = Blazar of uncertain type (57 sources)
    bcn = Blazar candidate (286 sources)
    sfr = Star-forming-HII region (90 sources)
    psr = Pulsar (88 sources + 23 in pulsar wind nebula (pwn) and 7 in snr)
    msp = Millisecond pulsar (51 sources)
    snr = Supernova remnant (79 sources + 12 with psr)
    gal = Normal galaxy (11 sources)
    rdg = Radio galaxy (10 sources)
    sbg = Starburst galaxy (3 sources)
    sey = Seyfert galaxy (3 sources)
    glc = Globular cluster (10 sources + 1 in sfr and 1 with psr)
    pwn = Pulsar wind nebula (6 sources + 6 with psr)
    hmb = High mass X-ray binary (2 sources + 3 in sfr)
    bin = Binary star (1 source)
  

Ctrpart_2_RA
The Right Ascension of the second proposed low-energy counterpart to the gamma-ray 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.

Ctrpart_2_Dec
The Declination of of the second proposed low-energy counterpart to the gamma-ray source in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.01 arcseconds in the original table.

Ctrpart_2_Bmag
The B magnitude for the second low-energy counterpart to the gamma-ray source taken from the USNO-B1 Catalog (Monet et al. 2003, AJ, 125, 984), only for the blazar candidates (bcn) and the unclassified (unc) sources.

Ctrpart_2_Rmag
The R magnitude for the second low-energy counterpart to the gamma-ray source taken from the USNO-B1 Catalog (Monet et al. 2003, AJ, 125, 984), only for the blazar candidates (bcn) and the unclassified (unc) sources.

Ctrpart_1_Bzb_Prob
The percentage probability that the first low-energy counterpart to the gamma-ray source has infrared colors similar to the known 1FGL BL Lac objects (entries with ctrpart_1_source_type = 'bzb'), as estimated with the KDE method (see Section 7 of the reference paper for more details).

Ctrpart_1_Bzq_Prob
The percentage probability that the first low-energy counterpart to the gamma-ray source has infrared colors similar to the known 1FGL radio-loud flat-radio-spectrum quasars (entries with ctrpart_1_source_type = 'bzq'), as estimated with the KDE method (see Section 7 of the reference paper for more details).

Class
The HEASARC Browse object classification of the first low-energy counterpart to the gamma-ray source based on the value of the ctrpart_1_source_type parameter.


Contact Person

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

Page Author: Browse Software Development Team
Last Modified: 6-Jan-2017