FER2FUSRID ivo://nasa.heasarc/fer2fusrid NASA/GSFC HEASARC Schinzel et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains some of the results from an all-sky radio survey between 5- and 9-GHz of sky areas surrounding all unassociated gamma-ray objects listed in the Fermi Large Area Telescope (LAT) Second Source Catalog (2FGL). The goal of these observations is to find all new gamma-ray active galactic nucleus (AGN) associations with radio sources > 10 mJy at 8GHz. The authors observed with the Very Large Array (VLA) and the Australia Telescope Compact Array (ATCA) the areas around unassociated sources, providing localizations of weak radio point sources found in 2FGL fields at arcminute scales. They then followed up a subset of these with the Very Long Baseline Array (VLBA) and the Long Baseline Array (LBA) in order to confirm detections of radio emission on parsec-scales. The authors quantified association probabilities based on known statistics of source counts and assuming a uniform distribution of background sources. In total, they found 865 radio sources at arcsecond scales as candidates for association and detected 95 of 170 selected for follow-up observations at milliarcsecond resolution. Based on this, they obtained firm associations for 76 previously unknown gamma-ray AGNs. Comparison of these new AGN associations with the predictions from using the Wide-field Infrared Survey Explorer (WISE) color-color diagram shows that half of the associations are missed. The authors found that in 129 out of 588 gamma-ray sources observed at arcminute scales not a single radio continuum source was detected above their sensitivity limit within the 3-sigma gamma-ray localization. These "empty" fields were found to be particularly concentrated at low Galactic latitudes. The nature of these Galactic gamma-ray emitters is not yet determined. A list of 216 target fields were observed with the VLA. The instantaneous bandwidth was split into two parts, with one half centered at 5.0 GHz (4.5 - 5.5 GHz) and the other centered at 7.3 GHz (6.8 - 7.8 GHz). The observations were made on 2012 October 26 and 2012 November 3. See section 2.1 of the reference paper for more details. These data are included in this HEASARC table. During the first campaign with the ATCA from 2012 September 19-20, the authors observed 411 2FGL unassociated sources in a Declination range of -90 degrees to +10 degrees at 5.5 and 9 GHz. The details of this observing campaign and results have been reported by Petrov et al. (2013, MNRAS, 432, 1294: available at the HEASARC as the AT2FGLUS table). The authors detected a total of 424 point sources. In a second ATCA campaign on 2013 September 25-28, the authors re-observed sources that were detected at 5 GHz, but were not detected at 9 GHz. See section 2.2 of the reference paper for more details. These data are included in this HEASARC table. Follow-up observations of 149 targets selected from the VLA and ATCA surveys above -30 degrees Declination were conducted with the VLBA between 2013 Feb-Aug (VCS7 project; 4.128 - 4.608 and 7.392 - 7.872 GHz simultaneously) and in 2013 Jun-Dec (campaign S5272; 7.392 - 7.872 GHz only). See section 2.3 of the reference paper for more details. These data are NOT included in this HEASARC table. For sources with Declination below -30 degrees, the authors added 21 objects to the on-going LCS campaign being conducted using the LBA (Petrov et al. 2011, MNRAS, 414, 2528) in 2013 Mar-2013 Jun at 8.200 - 8.520 GHz. See section 2.4 of the reference paper for more details. These data are NOT included in this HEASARC table. This table was created by the HEASARC in May 2015 based on the union of <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/217/4/">CDS Catalog J/ApJS/217/4/</a> files table2.dat (the 148 'Category I' objects that were detected at 5.0/5.5 and/or 7.3/9.0 GHz within 2.7' of the 2FGL counterpart localization), table3.dat (the 501 'Category II' objects that were detected at 5.0/5.5 and/or 7.3/9.0 GHz between 2.7' and 6.5' of the 2FGL counterpart localization) and table4.dat (the 216 'Category III' objects that were detected outside of the 6.5 arcminutes but still within the 99% positional uncertainty of the 2FGL counterpart localization). It thus contains a total of 865 objects. This is a service provided by NASA HEASARC . 2015ApJS..217....4S https://heasarc.gsfc.nasa.gov/W3Browse/all/fer2fusrid.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=fer2fusrid& GET text/xml 180 99999 true 157.56829167 -84.05311111 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=fer2fusrid GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_fer2fusrid&Action=More+Options&Action=Parameter+Search&ConeAdd=1 RADIO CATALOG 0.0166666666666667 Radio public fer2fusrid Fermi 2FGL Unassociated Gamma-Ray Sources Possible Radio Identif name IAU Designation of the Radio Source meta.id;meta.main char nullable fermi_2fgl_name 2FGL Designation of the Gamma-Ray Source (2FGL JHHMM.m+DDMMc) meta.id char nullable source_flag Flag(s) [ef] Indicates Note(s) Concerning Source meta.code;src char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable ra_error Uncertainty in Right Ascension (without cos{delta} Factor) arcsec stat.error;pos.eq.ra;meta.main double nullable dec_error Uncertainty in Declination arcsec stat.error;pos.eq.dec;meta.main double nullable flux_5_ghz Flux Density at 5 GHz mJy phot.flux.density;em.radio.3-6GHz double nullable flux_5_ghz_error Uncertainty in Flux Density at 5 GHz mJy stat.error;phot.flux.density;em.radio.3-6GHz double nullable spectral_index Spectral Index Between 5 and 9/7 GHz spect.index;em.radio.3-6GHz;em.radio.6-12GHz double nullable spectral_index_error Uncertainty in Spectral Index Between 5 and 9/7 GHz stat.error;spect.index;em.radio.3-6GHz;em.radio.6-12GHz double nullable lii Galactic Longitude degree pos.galactic.lon double nullable bii Galactic Latitude degree pos.galactic.lat double nullable flux_9_ghz Flux Density at 9 GHz mJy phot.flux.density;em.radio.6-12GHz double nullable campaign Radio Observation Campaign: V1=VLA, A1/A2=ATCA meta.code;obs char nullable spectral_index_5g Spectral Index Between 4.58 and 6.42 GHz spect.index;em.radio.3-6GHz double nullable offset_sigma Distance Between Gamma-Ray and Radio Source, Normalized by Its Uncertainty stat.stdev;pos.angDistance;em.radio;em.gamma double nullable flux_7_ghz_error Uncertainty in Flux Density at 7 GHz mJy stat.error;phot.flux.density;em.radio.6-12GHz double nullable category Number 1, 2, or 3 Indicates Spatial Offset Category of Radio Source meta.code short nullable spectral_index_9g Spectral Index Between 8.09 and 9.92 GHz spect.index;em.radio.6-12GHz double nullable spectral_index_9g_error Uncertainty in Spectral Index Between 8.09 and 9.92 GHz stat.error;spect.index;em.radio.6-12GHz double nullable flux_9_ghz_error Uncertainty in Flux Density at 9 GHz mJy stat.error;phot.flux.density;em.radio.6-12GHz double nullable flux_7_ghz Flux Density at 7 GHz mJy phot.flux.density;em.radio.6-12GHz double nullable spectral_index_5g_error Uncertainty in Spectral Index Between 4.58 and 6.42 GHz stat.error;spect.index;em.radio.3-6GHz double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable off_set Distance Between Gamma-Ray and Radio Source arcmin pos.angDistance;em.radio;em.gamma double nullable