MOSTATLAS ivo://nasa.heasarc/mostatlas NASA/GSFC HEASARC Randall et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source At the faintest radio flux densities (S<sub>1.4</sub> < 10 mJy), conflicting results have arisen regarding whether there is a flattening of the average spectral index between a low radio frequency (325 or 610 MHz) and, for example, 1.4 GHz. The authors present a new catalog of 843-MHz radio sources in the European Large Area ISO Survey-South 1 (ELAIS-S1) field, which contains the sources, their Australia Telescope Large Area Survey (ATLAS) counterparts and the spectral index distribution of the sources as a function of flux density. The authors do not find any statistically significant evidence for a trend towards flatter spectral indices with decreasing flux density. In the reference paper, they investigate the spectral index distribution with redshift for those sources with reliable redshifts and explore the infrared properties. An initial sample of faint compact steep-spectrum sources in ATLAS are also presented, with a brief overview of their properties. To obtain low-radio-frequency (843-MHz) data within the ATLAS ELAIS-S1 region (Middelberg et al. 2008, AJ, 135, 1276, the tables from which are available as the ATLASESID and ATLASESCPT tables in the HEASARC database), the authors used the Molonglo Observatory Synthesis Telescope (MOST). They have made 31 separate 12-h observations taken with MOST, which were combined into a single image with a spatial resolution of 62 arcsec x 43 arcsec. This table was created by the HEASARC in January 2013 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/421/1644">CDS Catalog J/MNRAS/421/1644</a> file table1.dat. This is a service provided by NASA HEASARC . 2012MNRAS.421.1644R https://heasarc.gsfc.nasa.gov/W3Browse/all/mostatlas.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=mostatlas& GET text/xml 180 99999 true 8.65103333 -45.70573611 0.0833333333333333 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=mostatlas GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_mostatlas&Action=More+Options&Action=Parameter+Search&ConeAdd=1 RADIO CATALOG 0.0833333333333333 Radio public mostatlas Molonglo Observatory Synthesis Telescope ATLAS 843-MHz Source Ca name Source Designation 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 atelais_name ATLAS IAU Designation of Positionally Closest ATLAS Source to MOST Source meta.id.cross char nullable flux_843_mhz 843-MHz Total Flux mJy phot.flux.density;em.radio.750-1500MHz double nullable flux_843_mhz_error 843-MHz Total Flux Error mJy stat.error;phot.flux.density;em.radio.750-1500MHz double nullable flux_2p3_ghz 2.3-GHz Flux Density from Zinn et al. mJy phot.flux.density;em.radio.1500-3000MHz double nullable flux_2p3_ghz_error 2.3-GHz Flux Density Error mJy stat.error;phot.flux.density;em.radio.1500-3000MHz double nullable bj_mag SuperCOSMOS BJ Magnitude mag phot.mag;em.opt.B 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 spectral_index_error Error in Three-Point Spectral Index stat.error;spect.index;em.radio double nullable lo_spectral_index Two-Point Spectral Index from 843-MHz and Convolved 1.4-GHz Flux Densities spect.index;em.radio double nullable bii Galactic Latitude degree pos.galactic.lat double nullable conv_flux_1p4_ghz_error Convolved 1.4-GHz Flux Density Error mJy stat.error;phot.flux.density;em.radio.750-1500MHz double nullable irac_3p6_um_flux SWIRE 3.6-Micron Flux Density microJy phot.flux.density;em.IR.3-4um double nullable hi_spectral_index_error Error in Two-Point Spectral Index from Convolved 1.4-GHz and 2.3-GHz Flux Dens. stat.error;spect.index;em.radio double nullable flux_1p4_ghz_error 1.4-GHz Flux Density Error from Middelberg et al. (2008, Cat. J/AJ/135/1276) mJy stat.error;phot.flux.density;em.radio.750-1500MHz double nullable hi_spectral_index Two-Point Spectral Index from Convolved 1.4-GHz and 2.3-GHz Flux Densities spect.index;em.radio double nullable irac_4p5_um_flux SWIRE 4.5-Micron Flux Density microJy phot.flux.density;em.IR.4-8um double nullable other_atlas_ids ATLAS IDs of Blended Sources Not Listed in Column ATLAS meta.id.cross char nullable source_flag Flag [bp] Indicates Blended or Single Point meta.code;src char nullable imag ESIS I Magnitude mag phot.mag;em.opt.I double nullable irac_8p0_um_flux SWIRE 8-Micron Flux Density microJy phot.flux.density;em.IR.4-8um double nullable conv_flux_1p4_ghz Convolved 1.4-GHz Flux Density from This Paper mJy phot.flux.density;em.radio.750-1500MHz double nullable mips_24_um_flux SWIRE 24-Micron Flux Density microJy phot.flux.density;em.IR.15-30um double nullable lo_spectral_index_error Error in Spectral Index from 843-MHz and Convolved 1.4-GHz Flux Densities stat.error;spect.index;em.radio double nullable spectral_index Three-Point Spectral Index Fitted to Available Flux Densities spect.index;em.radio double nullable first_atlas_id ATLAS Identification of Single/First ATLAS Match to MOST Source meta.id.cross char nullable redshift Spectroscopic or Photometric Redshift from Rowan-Robinson et al. src.redshift double nullable flux_1p4_ghz 1.4-GHz Flux Density from Middelberg et al. (2008, Cat. J/AJ/135/1276) mJy phot.flux.density;em.radio.750-1500MHz double nullable zmag ESIS z Magnitude mag phot.mag;em.opt double nullable comments Comments Concerning Source meta.note char nullable swire_name SWIRE Identification meta.id.cross char nullable lii Galactic Longitude degree pos.galactic.lon double nullable rmag R-Band Magnitude from Rowan-Robinson et al. mag phot.mag;em.opt.R double nullable irac_5p8_um_flux SWIRE 5.8-Micron Flux Density microJy phot.flux.density;em.IR.4-8um double nullable