J/ApJS/75/801 J/ApJS/75/801 MGIV M Griffith G Langston M Heflin S Conner B Burke Astrophys. J. Suppl. Ser. 75 801 1991 1991ApJS...75..801G VIII/38 : The Parkes-MIT-NRAO 4.85GHz (PMN) Surveys (Griffith+ 1993-1996) Radio sources Surveys radio sources: general radio sources: identifications The MIT-Green Bank IV (MG IV) 5 GHz survey covers 0.504 sr of sky in the right ascension range 15.5 to 2.5 hours, between +37.00 and +50.98 degrees declination (B1950). The final MG IV catalog contains 3427 sources detected with a signal-to-noise ratio greater than 5. The catalog was produced from two separate north and south surveys with the National Radio Astronomy Observatory (NRAO) 91m transit telescope. The north survey was produced from data collected while scanning the telescope north from +39.0 to +50.98 degrees declination and the south survey from data collected from scans from +48.98 to +37.00 degrees declination. The completeness and reliability of the final source list is checked by examination of north and south source lists in a twice observed comparison region, lying between +39.15 and +48.83 degrees declination and excluding the area between +/-10 degrees Galactic latitude. The comparison region covers 0.270 sr of sky and contains 1094 sources. In this region, the MG IV catalog contains 423 sources brighter than 90 mJy and is shown to be 99.1 +/- 1.2% complete at this flux density level. Spectral indices are computed for sources identified in the NRAO 1400 MHz Survey (published by Condon and Broderick in 1985). A comparison of the spectral index distributions between +/- 10 and outside of +/- 10 degrees Galactic latitude is presented. Nomenclature Note: The source names are derived from the J2000 coordinates; a 'J' was added in front of this name to comply with IAU recommendations on designations, and the suffix 'a' or 'b' was added for 132 sources with identical names.

Name The source names are derived from the J2000 coordinates (see "Nomenclature Note" section above) --- RAh right ascension J2000 h RAm right ascension J2000 min RAs right ascension J2000 s DE- declination sign --- DEd declination J2000 deg DEm declination J2000 arcmin DEs declination J2000 arcsec RA1950h right ascension B1950.0 h RA1950m right ascension B1950.0 min RA1950s right ascension B1950.0 s DE1950- declination sign --- DE1950d declination B1950.0 deg DE1950m declination B1950.0 arcmin DE1950s declination B1950.0 arcsec S4.83GHz 4.830 GHz Green Bank flux density mJy S/N Signal-to-noise ratio of the detection. The MGIV source list is defined by S/N >= 5 --- G Group containing the source G is defined by the north or south survey detecting the source and the source location in the survey. Sources with b > +10 deg and detected in the south, north, or both surveys are assigned to groups 0, 1, 2. Sources lying in regions observed only once or at low Galactic latitude |b| < 10 deg, and detected in the south, north, or both surveys are assigned to groups 3, 4, or 5. Sources in the region observed twice but with b < -10 deg and detected in south, north, or both surveys, are assigned to groups 6, 7, or 8 --- alpha The NRAO 1400 MHz-MGIV spectral index, alpha(1400 MHz, 4830 MHz), where S {prop.to.} {nu}^alpha^ --- Patricia Bauer, Francois Ochsenbein CDS 1998Oct07Mark Griffith griffith@maggie.mit.edu Authors' addresses: Mark Griffith, Bernard Burke, Sam Conner, And Mike Heflin: Room 26-335, Massachusetts Institute of Technology, Cambridge, MA 02139 (Phone 1-617-253-2572) Glen Langston National Radio Astronomy Observatory , Edgemont Road, Charlottesville, Va 22903 (Phone 1-804-296-0328) UNKNOWN UNKNOWN * 13-Oct-1998: the suffix 'a' or 'b' was added in byte position 14 of table4 to distinguish sources with colliding names. (done for consecutive identical names) * 13-Oct-1998: the suffix 'a' 'b' or 'c' was added in byte position 14 (done for all 132 sources with colliding names) J_ApJS_75_801.xml