VLAXL74MHZ ivo://nasa.heasarc/vlaxl74mhz NASA/GSFC HEASARC Tasse et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The XMM Large Scale Structure survey (XMM-LSS) is an X-ray survey aimed at studying the large scale structure of the Universe. The XMM-LSS field (centered at RA (J2000) = 02<sup>h</sup> 24<sup>m</sup> 00.27<sup>s</sup>, Dec (J2000) = -04<sup>o</sup> 09' 47.6") is currently being followed up using observations across a wide range of wavelengths, and in their paper the authors present the observational results of a low frequency radio survey of the XMM-LSS field using the Very Large Array at 74 and 325 MHz. This survey will map out the locations of the extragalactic radio sources relative to the large scale structure as traced by the X-ray emission. This is of particular interest because radio galaxies and radio-loud AGN show strong and complex interactions with their small and larger scale environment, and different classes of radio galaxies are suggested to lie at different places with respect to the large scale structure. For the phase calibration of the radio data, the authors used standard self-calibration at 325 MHz and field-base calibration at 74 MHz. Polyhedron-based imaging as well as mosaicking methods were used at both frequencies. At 74 MHz, the resolution was 30 arcseconds, the median 5-sigma sensitivity was ~ 162 mJy/beam and 666 sources were detected over an area of 132 square degrees. At 325 MHz, the resolution was 6.7 arcseconds, the median 5-sigma sensitivity was 4 mJy/beam, and 847 sources were detected over an area of 15.3 square degrees. At 325 MHz, a region of diffuse radio emission which is a cluster halo or relic candidate was detected. The observations were conducted using the VLA in July 2003 in the A-configuration (most extended) and in June 2002 in the B-configuration. This table contains the VLA 74-MHz source list, comprising 617 single sources and 108 components of 51 multiple sources, for a total of 725 entries. (Notice that, in Section 4.3 of the reference paper, somewhat different numbers are given, i.e., the authors quote 615 single sources). For the multiple sources, each component (A, B, etc.) is listed separately, in order of decreasing brightness. This table was created by the HEASARC in March 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/456/791">CDS Catalog J/A+A/456/791</a> file tablea2.dat. This is a service provided by NASA HEASARC . 2006A&A...456..791T https://heasarc.gsfc.nasa.gov/W3Browse/all/vlaxl74mhz.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=vlaxl74mhz& GET text/xml 180 99999 true 35.83666667 -10.38901667 0.0833333333333333 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=vlaxl74mhz GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_vlaxl74mhz&Action=More+Options&Action=Parameter+Search&ConeAdd=1 RADIO CATALOG 0.0833333333333333 Radio public vlaxl74mhz VLA XMM Large Scale Structure Field 74-MHz Source Catalog name Source Designation ([TCR2006] JHHMM.m+DDMMc) meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable ra_error RMS Uncertainty in Right Ascension arcsec stat.error;pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable dec_error RMS Uncertainty in Declination arcsec stat.error;pos.eq.dec;meta.main double nullable flux_74_mhz Flux Density at 74 MHz mJy phot.flux.density;em.radio.20-100MHz double nullable flux_74_mhz_error RMS Uncertainty in Flux Density at 74 MHz of Individual Component mJy stat.error;phot.flux.density;em.radio.20-100MHz double nullable spectral_index_limit Limit Flag for Spectral Index meta.code;spect.index char nullable spectral_index Spectral Index with Respect to NVSS (VIII/65) Flux Density (1.4GHz) spect.index double nullable major_axis_limit Limit Flag for Major Axis meta.code;phys.size.smajAxis char nullable major_axis Size of Major Axis arcsec phys.size.smajAxis double nullable minor_axis_error RMS Uncertainty in Minor Axis arcsec stat.error;phys.size.sminAxis double nullable bii Galactic Latitude degree pos.galactic.lat double nullable minor_axis Size of Minor Axis arcsec phys.size.sminAxis double nullable position_angle Position Angle degree pos.posAng double nullable major_axis_error RMS Uncertainty in Major Axis arcsec stat.error;phys.size.smajAxis double nullable lii Galactic Longitude degree pos.galactic.lon double nullable source_type Flag [SMC] Indicates Source Type: (S)ingle, (M)ultiple or (C)omponent src.morph char nullable detect_2_freq_flag Flag [Y] Indicates Source Detected at 325 MHz and 74 MHz meta.code;src char nullable minor_axis_limit Limit Flag for Minor Axis meta.code;phys.size.sminAxis char nullable position_angle_error RMS Uncertainty in Position Angle degree stat.error;pos.posAng 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