ACTSSRCAT ivo://nasa.heasarc/actssrcat NASA/GSFC HEASARC Marsden et al. 2026-07-17 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains a catalog of 191 extragalactic sources detected by the Atacama Cosmology Telescope (ACT) at 148 and/or 218 GHz in the 2008 Southern survey. Flux densities span 14 -1700 mJy, and the authors use source spectral indices derived using ACT-only data to divide their sources into two subpopulations: 167 radio galaxies powered by central active galactic nuclei (AGN) and 24 dusty star-forming galaxies (DSFGs). They cross-identify 97% of their sources (166 of the AGN and 19 of the DSFGs) with those in currently available catalogs. When combined with flux densities from the Australia Telescope 20-GHz survey and follow-up observations with the Australia Telescope Compact Array, the synchrotron-dominated population is seen to exhibit a steepening of the slope of the spectral energy distribution from 20 to 148 GHz, with the trend continuing to 218 GHz. The ACT dust-dominated source population has a median spectral index, alpha<sub>148-218GHz</sub>, of 3.7<sup>+0.62</sup><sub>-0.86</sub>, and includes both local galaxies and sources with redshift around 6. Dusty sources with no counterpart in existing catalogs likely belong to a recently discovered subpopulation of DSFGs lensed by foreground galaxies or galaxy groups. The ACT experiment (Swetz et al., 2011, ApJS, 194, 41) is situated on the slopes of Cerro Toco in the Atacama Desert of Chile at an elevation of 5190m. ACT's latitude gives access to both the northern and southern celestial hemispheres. Observations occurred simultaneously in three frequency bands, at 148 GHz (2.0 mm), 218 GHz (1.4 mm) and 277 GHz (1.1 mm) with angular resolutions of roughly 1.4, 1.0 and 0.9 arcminutes, respectively. The ACT-detected source list contains 169 sources selected at 148 GHz with S/N > 5, spanning two decades in flux density, from 14 to 1700 mJy. The 218 GHz map independently yielded 133 sources with S/N > 5. The combination of these two independent source lists from which the present table was constructed gives a total count of 191 sources, with 110 galaxies detected with S/N > 5 at both frequencies. This table was created by the HEASARC in May 2015 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/439/1556/">CDS Catalog J/MNRAS/439/1556/</a> file table4.dat. This is a service provided by NASA HEASARC . 2014MNRAS.439.1556M https://heasarc.gsfc.nasa.gov/W3Browse/all/actssrcat.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=actssrcat& GET text/xml 180 99999 true 63.65125 -56.06375 0.0833333333333333 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=actssrcat GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_actssrcat&Action=More+Options&Action=Parameter+Search&ConeAdd=1 GROUND-BASED 0.0833333333333333 Radio public actssrcat Atacama Cosmology Telescope 2008 Southern Survey 148/218 GHz Sou name ACT-S Source Designation (ACT-S 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_148_ghz Deboosted Flux Density at 148 GHz mJy phot.flux.density;em.mm.100-200GHz double nullable flux_148_ghz_neg_err Negative Error on Deboosted Flux Density at 148 GHz mJy stat.error;phot.flux.density;em.mm.100-200GHz double nullable flux_148_ghz_pos_err Positive Error on Deboosted Flux Density at 148 GHz mJy stat.error;phot.flux.density;em.mm.100-200GHz double nullable flux_218_ghz Deboosted Flux Density at 218 GHz mJy phot.flux.density;em.mm.200-400GHz double nullable flux_218_ghz_neg_err Negative Error on Deboosted Flux Density at 218 GHz mJy stat.error;phot.flux.density;em.mm.200-400GHz double nullable flux_218_ghz_pos_err Positive Error on Deboosted Flux Density at 218 GHz mJy stat.error;phot.flux.density;em.mm.200-400GHz 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 lii Galactic Longitude degree pos.galactic.lon double nullable meas_flux_148_ghz Flux Density Measured Directly from the ACT 148-GHz Map mJy phot.flux.density;em.mm.100-200GHz double nullable spectral_index Deboosted Spectral Index Between 148 and 218GHz (Alpha) spect.index;em.mm.100-200GHz;em.mm.200-400GHz double nullable source_flag Flag [d] Indicates No Cross-Identification meta.code;src char nullable at20g_name AT20G Source Designation meta.id.cross char nullable snr_148_ghz Signal-to-Noise Ratio at 148 GHz stat.snr;phot.flux.density;em.mm.100-200GHz double nullable flux_20_ghz Flux Density at 20 GHz mJy phot.flux.density;em.radio.12-30GHz double nullable flux_20_ghz_error RMS Uncertainty in Flux Density at 20 GHz mJy stat.error;phot.flux.density;em.radio.12-30GHz double nullable snr_218_ghz Signal-to-Noise Ratio at 218GHz stat.snr;phot.flux.density;em.mm.200-400GHz double nullable meas_flux_218_ghz Flux Density Measured Directly from the ACT 218-GHz Map mJy phot.flux.density;em.mm.200-400GHz double nullable meas_spectral_index Raw Spectral Index Between 148 and 218 GHz spect.index;em.mm.100-200GHz;em.mm.200-400GHz double nullable spectral_index_neg_err Negative Error on Deboosted Spectral Index Between 148 and 218GHz (Alpha) stat.error;spect.index;em.mm.100-200GHz;em.mm.200-400GHz double nullable source_class Classification Code src.class char nullable spectral_index_pos_err Positive Error on Deboosted Spectral Index Between 148 and 218GHz (Alpha) stat.error;spect.index;em.mm.100-200GHz;em.mm.200-400GHz double nullable bii Galactic Latitude degree pos.galactic.lat double nullable at20g_flag Flag [f] Indicates from 2010 November Follow-Up Observation Catalog char nullable