J/MNRAS/394/2197ivo://CDS.VizieR/J/MNRAS/394/2197doi:10.26093/cds/vizier.73942197CDSBryant J.J.Broderick J.W.Johnston H.M.Hunstead R.W.Gaensler B.M.,De Breuck C.2024-07-08T20:15:33Z2015-07-09T07:34:10ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsurveysradio-galaxiesinfrared-photometrygalaxy-classification-systemsWe have compiled a sample of 234 ultra-steep-spectrum (USS) selected radio sources in order to find high-redshift radio galaxies. The sample covers the declination range -40{deg}<{delta}<-30{deg} in the overlap region between the 1400-MHz National Radio Astronomy Observatory (NRAO) Very Large Array (VLA) Sky Survey (NVSS), 408-MHz Revised Molonglo Reference Catalogue and the 843-MHz Sydney University Molonglo Sky Survey (the MRCR-SUMSS sample). This is the second in a series of papers on the MRCR-SUMSS sample, and here we present the K-band (2.2{mu}m) imaging of 173 of the sources primarily from the Magellan and the Anglo-Australian Telescopes. We detect a counterpart to the radio source in 93 per cent of the new K-band images which, along with previously published data, makes this the largest published sample of K-band counterparts to USS-selected radio galaxies. The location of the K-band identification has been compared to the features of the radio emission for the double sources. We find that the identification is most likely to lie near the mid-point of the radio lobes rather than closer to the brighter lobe, making the centroid a less likely place to find the optical counterpart. 79 per cent of the identifications are less than 1arcsec from the radio lobe axis. These results differ from studies of low-redshift radio samples where the environments are typically not nearly so dense and disturbed as those at high redshift. In contrast to some literature samples, we find that the majority of our sample shows no alignment between the near-infrared and radio axes. Several different morphologies of aligned structures are found and those that are aligned within 10{deg} are consistent with jet-induced star formation. The distribution and median value of the K-band magnitudes for the MRCR-SUMSS sample are found to be similar to several other USS-selected samples even though each sample has a very different median 1400MHz flux density. USS selection from a lower radio-frequency sample has not netted fainter K-band magnitudes, which may imply that the k-correction is not responsible for the effectiveness of USS selection.2009MNRAS.394.2197Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/394/2197CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/347/837 : Radio & K-band obs. of Ultra-Steep sources (De Breuck+, 2004)J/MNRAS/381/341 : MRCR-SUMSS Ultra-steep-spectrum sample (Broderick+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/394/2197https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/394/2197http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/394/2197https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/394/2197https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/394/2197http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/394/2197GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/394/2197/table2 (K-band photometry results)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/394/2197/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/394/2197/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/394/2197/table2?GETtext/xml+votable180.050000true0.63125-34.43780560.0055555555555555566/16393-16394 16398 16400 16402 16405 16411 16427 16433 16435 16458 16463 16468 16472 16488 16514 16521-16522 24585 24588 24606 24737 34552 35257 35296 35314 35447-35448 35536 35539 35553 35559-35561 35565 35569-35570 35587 35598 35604 35608 35625 35636 35688 35713 35717 35887 35895 35900 35902-35903 35913 35973 35982 36006 36010 38259 38266 38330 38339 38344-38345 38360 38380 38517-38518 38612 38660 38663 38701 38711 38744 42675 42684-42685 42724 42728 42730 42736 43359 43379 43383 43445 43461-43462 43467 43474 43479 43490-43491 43497 43502 43516 43631 43636 43638 43645 43702 43745 43793 43815 44035-44036 44044 44046 44048-44049 44051 44055 44057 44064 44068 44070 44075 44120 46452 46454 46463 46535 46541 46548 46552 46563 46571 46584 46803 46811 46814 46829 46831 46833 46840 46861 46874 46876 46889-46890 46892 46894 46912 46936 47455 47574-47576 47581 48153 48174 48183 48193 48195 48211 482243.180513520130092e-24 5.724924336234166e-24https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/394/2197?format=asciiOpticalInfraredRadiodefaultJ/MNRAS/394/2197/table2K-band photometry resultsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRSimbad column added by the CDSmeta.ref.urlcharNVSSNVSS name (JHHMMSS+DDMMSS)meta.id;meta.maincharprimaryn_NVSS[ahi] Note on NVSS (1)meta.notecharl_K4magLimit flag on Kmagmeta.code.errorcharK4mag? K magnitude in 4" diameter-aperturemagphot.mag;em.IR.Kfloatnullablee_K4mag? rms uncertainty on K4magmagstat.error;phot.mag;em.IR.Kfloatnullablen_K4mag[SC, de] Note on K4mag (1)meta.notecharK8mag? K magnitude in 8" diameter-aperturemagphot.mag;em.IR.Kfloatnullablee_K8mag? rms uncertainty on K8magmagstat.error;phot.mag;em.IR.KfloatnullableLAS[1/73]? Largest angular size from the natural-weighted 2368MHz imagearcsecphys.angSize;stat.maxfloatnullableRAJ2000? Right ascension from K band (J2000) (2)pos.eq.ra;meta.mainnullableDEJ2000? Declination from K band (J2000) (2)pos.eq.dec;meta.mainnullablepos[bck] Origin of the position (1)meta.ref;pos.framecharTint[3/99]? K-band image exposure timemintime.duration;obs.image;obs.exposureintnullableSrcOrigin of K imaging (3)meta.notecharalpha[-1.9/-0.3]? Spectral index {alpha} from the five-point fit from Paper I (4)spect.indexfloatnullablee_alpha[0.04/0.12]? rms uncertainty on alphastat.error;pos.eq.rafloatnullablen_alpha[fjg] Note on alpha (1)meta.notecharl_LASLimit flag on LASmeta.code.errorcharJ/MNRAS/394/2197/table34800- and 8640-MHz ATCA radio propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNVSSNVSS name (JHHMMSS+DDMMSS)meta.id;meta.maincharS4.84800MHz integrated flux densitymJyphot.flux.density;em.radio.3-6GHzfloate_S4.8rms uncertainty on S4.8mJystat.errorfloatS8.68640MHz integrated flux densitymJyphot.flux.density;em.radio.6-12GHzfloate_S8.6rms uncertainty on S8.6mJystat.errorfloatalpha1[-2/0.6] Two point observed-frame spectral index {alpha}^8640^_4800_spect.indexfloate_alpha1[0.1/0.4] rms uncertainty on alpha1stat.errorfloatalpha2[-1.5/0.9]? Seven-point observed-frame spectral index {alpha} (1)spect.indexfloatnullablee_alpha2[0.02/0.03]? rms uncertainty on alpha2stat.errorfloatnullablen_alpha2[f] f for sources that have curved spectra that flatten at high frequency (2)meta.notecharl_LASLimit flag on LASmeta.code.errorcharLAS[0.9/33]Largest angular size (3)arcsecphys.angSize;stat.maxfloatn_LAS[a] a: LAS obtained from 2368MHz imagemeta.notecharPA[-90/90]? Deconvolved position angle of the radio structure, measured from the north to the east (4)degpos.posAngintnullable