J/ApJS/143/1ivo://CDS.VizieR/J/ApJS/143/1doi:10.26093/cds/vizier.21430001CDSMcMahon R.G.White R.L.Helfand D.J.Becker R.H.2003-04-26T22:20:23Z2003-04-26T22:13:26ZCDS support team

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

cds-question@unistra.frradio-sourcesquasarssurveysastronomical-object-identificationWe describe a program to identify optical counterparts to radio sources from the VLA FIRST survey using the Cambridge APM scans of the POSS-I plates. We use radio observations covering 4150deg^2^ of the north Galactic cap to a 20cm flux density threshold of 1.0mJy; the 382,892 sources detected all have positional uncertainties of <1" (radius of 90% confidence). Our description of the APM catalog, derived from the 148 POSS-I O and E plates covering this region, includes an assessment of its astrometric and photometric accuracy, a photometric recalibration using the Minnesota APS catalog, a discussion of the classification algorithm, and quantitative tests of the catalog's reliability and completeness. We go on to show how the use of FIRST sources as astrometric standards allows us to improve the absolute astrometry of the POSS plates by nearly an order of magnitude to ~0.15" rms. Matching the radio and optical catalogs yields counterparts for over 70,000 radio sources; we include detailed discussions of the reliability and completeness of these identifications as a function of optical and radio morphology, optical magnitude and color, and radio flux density. An analysis of the problem of radio sources with complex morphologies (e.g., double-lobed radio galaxies) is included. We conclude with a brief discussion of the source classes represented among the radio sources with identified counterparts.2002ApJS..143....1Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/143/1CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/71 : The FIRST Survey, Version 2003Apr (Becker+ 2003)VIII/59 : the FIRST Survey, version 1999Jul (White+ 1999)I/267 : The APM-North Catalogue (McMahon+, 2000)http://sundog.stsci.edu/ : The VLA FIRST Survey Home Pagehttp://www.ast.cam.ac.uk/~apmcat/ : APM Catalog Home Pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/143/1https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/143/1http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/143/1https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/143/1https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/143/1http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/143/1GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/143/1/table4 (FIRST-APM Source Catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/143/1/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/143/1/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/143/1/table4?GETtext/xml+votable180.050000true134.2853583357.589833330.0055555555555555562/21 22 25 38 41 42 3/77 78 79 81 82 83 92 97 99 112 141 142 143 145 146 147 150 156 161 162 163 172 176 445 446 447 4/285 286 287 301 302 303 305 306 307 321 322 323 372 373 374 376 377 378 385 387 421 432 433 435 436 437 438 452 453 454 456 457 458 541 542 543 557 558 559 561 562 563 577 578 579 592 594 595 598 604 606 628 630 632 633 634 641 642 643 692 693 694 696 697 698 708 709 710 712 713 714 1757 1758 1759 1773 1774 1775 1777 1778 1779 2030 5/1119 1135 1139 1183 1199 1203 1219 1283 1500 1516 1517 1518 1520 1522 1539 1545 1572 1573 1575 1681 1683 1692 1693 1736 1737 1739 1756 1757 1758 1777 1820 1821 1822 1836 1838 1840 1841 1856 1920 1921 1922 2143 2159 2161 2163 2207 2223 2227 2241 2243 2305 2307 2372 2374 2375 2386 2428 2430 2516 2518 2524 2540 2544 2563 2780 2781 2782 2796 2797 2798 2800 2801 2844 2860 2861 2864 2880 2944 2945 2946 7007 7023 7027 7071 7087 7091 7107 8111 8114 8115 8124 8126 8127 8170 6/4469 4470 4471 4473 4474 4475 4533 4534 4535 4537 4538 4539 4549 4550 4551 4553 4554 4555 4725 4726 4727 4729 4730 4731 4789 4790 4791 4793 4794 4795 4805 4806 4807 4809 4810 4811 4869 4870 4871 4873 4874 4875 5125 5126 5127 5129 5130 5131 6004 6005 6006 6008 6009 6010 6076 6084 6085 6086 6096 6149 6150 6151 6153 6154 6155 6176 6177 6179 6188 6189 6191 6297 6325 6327 6333 6720 6721 6723 6729 6756 6757 6781 6952 6953 6955 7060 7061 7104 7105 7107 7120 7292 7348 7349 7350 7356 7368 7369 7370 7428 7429 7430 7432 7433 7434 7436 7440 7456 7696 8559 8565 8566 8567 8569 8570 8571 8629 8630 8631 8633 8634 8635 8643 8649 8650 8651 8821 8822 8823 8825 8826 8827 8885 8886 8887 8889 8890 8891 8901 8902 8903 8905 8906 8907 8963 8969 8970 8971 9219 9225 9226 9227 9492 9494 9495 9550 9551 9584 9592 9594 9680 9682 9688 9690 9691 10078 10100 10102 10104 10105 10106 10164 10165 10166 10168 10169 10170 10180 10181 10182 10184 10185 10186 10245 10246 10247 10249 10250 10251 11196 11208 11209 11210 11212 11216 11232 11380 11381 11382 11384 11385 11386 11448 11449 11450 11460 11461 11462 11464 11465 11466 11472 11524 11525 11526 11528 11529 11530 11788 11792 11808 28021 28022 28023 28025 28026 28027 28085 28086 28087 28089 28090 28091 28101 28102 28103 28105 28106 28107 28277 28278 28279 28281 28282 28283 28341 28342 28343 28345 28346 28347 28357 28358 28359 28361 28362 28363 28421 28422 28423 28425 28426 28427 32437 32438 32439 32441 32442 32443 32454 32455 32466 32472 32474 32475 32500 32502 32503 32672 32674 32675 32684 32686 32687 32698https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/143/1?format=asciiRadiodefaultJ/ApJS/143/1/table4FIRST-APM Source CatalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Radio hour of Right Ascension (J2000) (1)pos.eq.ra;meta.mainindexedDEJ2000Radio degree of Declination (J2000) (1)pos.eq.dec;meta.mainindexedoRARight Ascension offset to the optical objectarcsecpos.eq.ra;arith.difffloatoDEDeclination offset to the optical objectarcsecpos.eq.dec;arith.difffloatSepRadius to the optical objectarcsecpos.angDistancefloatEclassAPM classification on E (red) plate (2)meta.code.classintEpsfAPM psf parameter on E (red) plate (3)src.class.starGalaxyfloatEmagE (red) plate magnitude (1)(4)magphot.mag;em.opt.RfloatOclassAPM classification on O (blue) plate (2)meta.code.classintOpsfAPM psf parameter on O (blue) plate (3)src.class.starGalaxyfloatOmagO (blue) plate magnitude (1)(4)magphot.mag;em.opt.BfloatO-EThe (O-E) plate color (5)magphot.color;em.opt.B;em.opt.RfloatPlate? Number of POSS-I platemeta.numberintnullableFpeakFIRST peak radio flux density at 1.4GHz (6)mJyphot.flux.density;em.radio.750-1500MHzdoubleFintFIRST integrated radio flux density (6)mJyphot.flux.density;em.radio.750-1500MHzdoubleFmajFIRST source deconvolved major axis (6)(7)arcsecphys.angSizefloatFminFIRST source deconvolved minor axis (6)(7)arcsecphys.angSizefloatFPAFIRST position angle (6)degpos.posAngfloatAPMLink to APM (North) datameta.refcharFIRSTLink to FIRST datameta.refchar