ATLBS1P4GH ivo://nasa.heasarc/atlbs1p4gh NASA/GSFC HEASARC Thorat et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The Australia Telescope Low-brightness Survey (ATLBS) regions have been mosaic imaged at a radio frequency of 1.4 GHz with 6 arcseconds angular resolution and 72 microJansky per beam (µJy/beam) rms noise. The images (centered at RA 00<sup>h</sup> 35<sup>m</sup> 00<sup>s</sup>, Dec -67<sup>o</sup> 00' 00" and RA 00<sup>h</sup> 59<sup>m</sup> 17<sup>s</sup>, Dec -67<sup>o</sup> 00' 00", J2000 epoch) cover 8.42 deg<sup>2</sup> sky area and have no artifacts or imaging errors above the image thermal noise. Multi-resolution radio and optical r-band images (made using the 4 m CTIO Blanco telescope) were used to recognize multi-component sources and prepare a source list of 1366 1.4-GHZ sources; the detection threshold was 0.38 mJy in a low-resolution radio image made with beam FWHM of 50 arcseconds. Radio source counts in the flux density range 0.4-8.7 mJy are estimated, with corrections applied for noise bias, effective area correction, and resolution bias. The resolution bias is mitigated using low-resolution radio images, while effects of source confusion are removed by using high-resolution images for identifying blended sources. Below 1 mJy the ATLBS counts are systematically lower than the previous estimates. Showing no evidence for an upturn down to 0.4 mJy, they do not require any changes in the radio source population down to the limit of the survey. The work suggests that automated image analysis for counts may be dependent on the ability of the imaging to reproduce connecting emission with low surface brightness and on the ability of the algorithm to recognize sources, which may require that source finding algorithms effectively work with multi-resolution and multi-wavelength data. The work underscores the importance of using source lists - as opposed to component lists - and correcting for the noise bias in order to precisely estimate counts close to the image noise and determine the upturn at sub-mJy flux density. This table was created by the HEASARC in April 2013 based on an electronic version of Table 2 from the reference paper that was obtained from the ApJ web site.. This is a service provided by NASA HEASARC . 2013ApJ...762...16T https://heasarc.gsfc.nasa.gov/W3Browse/all/atlbs1p4gh.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=atlbs1p4gh& GET text/xml 180 99999 true 9.74 -68.101 0.0833333333333333 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=atlbs1p4gh GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_atlbs1p4gh&Action=More+Options&Action=Parameter+Search&ConeAdd=1 RADIO CATALOG 0.0833333333333333 Radio public atlbs1p4gh Australia Telescope Low-Brightness Survey Source Catalog 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 flux_1p4_ghz Integrated Flux Density mJy phot.flux.density;em.radio.750-1500MHz double nullable source_type Source Type Based on high resolution image src.class char nullable number_cpts Number of components for complex sources meta.number short nullable lii Galactic Longitude degree pos.galactic.lon double nullable bii Galactic Latitude degree pos.galactic.lat 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