OVRO31GHZ ivo://nasa.heasarc/ovro31ghz NASA/GSFC HEASARC Mason et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The 100m Robert C. Byrd Green Bank Telescope (GBT) and the 40m Owens Valley Radio Observatory (OVRO) telescope have been used to conduct a 31-GHz survey of 3165 known extragalactic radio sources over 143 deg<sup>2</sup> of the sky. Target sources were selected from the NRAO VLA Sky Survey (NVSS) in fields observed by the Cosmic Background Imager (CBI); most are extragalactic active galactic nuclei (AGNs) with 1.4-GHz flux densities of 3-10 mJy. Using a maximum-likelihood analysis to obtain an unbiased estimate of the distribution of the 1.4 - 31 GHz spectral indices of these sources, the authors find a mean 31 - 1.4 GHz flux ratio of 0.110 +/- 0.003 corresponding to a spectral index alpha = -0.71+/-0.01 (S<sub>nu</sub> ~ nu<sup>alpha</sup>); 9.0% +/- 0.8% of the sources have alpha > -0.5 and 1.2% +/- 0.2% have alpha > 0. By combining this spectral-index distribution with 1.4GHz source counts, the authors predict 31-GHz source counts in the range 1 mJy <S<sub>31</sub> < 4 mJy, N(>S<sub>31</sub>) = (16.7+/-1.7)deg<sup>-2</sup>(S<sub>31</sub>/1mJy)<sup>(-0.80+/-0.07)</sup>. In this study, the authors present a detailed characterization of the impact of the discrete source foreground on arcminute-scale 31-GHz anisotropy measurements based upon two observational campaigns. The first campaign (the results of which are given in this table) was carried out with the OVRO 40m telescope at 31 GHz from 2000 September through 2002 December. The second campaign (the results of which are given in the GBT31GHZ table) used the GBT from 2006 February to May. A companion paper (Sievers et al. 2009arXiv0901.4540S) presents the five-year CBI total intensity power spectrum incorporating the results of the point-source measurements discussed here. Reported error bars include a 10% and 5% rms gain uncertainty for GBT and OVRO measurements, respectively. Sources detected at greater than 4 sigma at 31 GHz are flagged (detection_flag = 'Y'); for this calculation, the random gain uncertainty was excluded. In all 3165 sources were observed. The GBT catalog (the HEASARC GBT31GHZ table) contains 1490 sources. Of the 2315 useful OVRO observations many of the non-detections (and a few detections) were superceded by more sensitive GBT observations; the OVRO catalog contained in the present table therefore contains data on 1675 sources. The detection rate of the OVRO measurements was 11%, and that of the GBT measurements 25%. In all, 18% of the sources were detected at 31 GHz. This table was created by the HEASARC in June 2012 based on CDS Catalpog J/ApJ/704/1433 file table2.dat. This is a service provided by NASA HEASARC . 2009ApJ...704.1433M https://heasarc.gsfc.nasa.gov/W3Browse/all/ovro31ghz.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=ovro31ghz& GET text/xml 180 99999 true 44.42491667 -5.49847222 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=ovro31ghz GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_ovro31ghz&Action=More+Options&Action=Parameter+Search&ConeAdd=1 RADIO CATALOG 0.0166666666666667 Radio public ovro31ghz Owens Valley Radio Observatory 40-m 31-GHZ Radio Source Catalog name NVSS Source Designation (NVSS JHHMMSS+DDMMSS) meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable flux_31_ghz The 31-GHz Flux Density mJy phot.flux.density;em.mm.30-50GHz double nullable flux_31_ghz_error Uncertainty in the 31-GHz Flux Density mJy stat.error;phot.flux.density;em.mm.30-50GHz double nullable flux_1p4_ghz The 1.4-GHz NVSS Integrated Flux Density mJy phot.flux.density;em.radio.750-1500MHz double nullable flux_1p4_ghz_error Uncertainty in the 1.4-GHz NVSS Integrated Flux Density mJy stat.error;phot.flux.density;em.radio.750-1500MHz double nullable detection_flag Flag [Y] Indicates Detection >= 4-Sigma meta.code;src char nullable minor_axis_1p4_ghz The 1.4-GHz NVSS Minor Axis arcsec phys.angSize.sminAxis double nullable lii Galactic Longitude degree pos.galactic.lon double nullable conf_corr_flag Flag [Y] Indicates Confusion-Corrected Flux (See Appendix A) meta.code char nullable bii Galactic Latitude degree pos.galactic.lat double nullable major_axis_1p4_ghz The 1.4-GHz NVSS Major Axis arcsec phys.angSize.smajAxis 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