Search for Compact Extragalactic Radio Sources Near Massive(11)

We have used the Very Large Array to search for compact milliarcsecond-size radio sources near methanol masers in high-mass star-forming regions. Such sources are required for Very Long Baseline Interferometry phase-referencing observations. We conducted p

Table4—Continued

SourceName

SourcePositionα(2000)δ(2000)

1.4GHz

(mJy)

5GHz(mJy)

15GHz(mJy)

SpectralIndex

θ(′′)

Note.—The rstcolumnpresentssourcenameforthemasers(boldface)andtheextragalacticradiosources.ThenexttwocolumnslisttheirJ2000equatorialcoordinates.Forthemasersourcesthenextcolumngivesacommonname(ifavailable).Forthecalibratorsourcescolumns4to6givetheintegrated uxdensityatL-(fromNVSS),peak uxdensityatC-andU-bands,respectively.Column7isthespectralindexbetweenC-andU-bands(Sν～ν α).Column8istheupperlimitsofsourcesizes(FWHMofthemaximummajoraxesofthesourcesasdeterminedfromtheGaussian tsusingAIPStaskJMFIT).ThedatacomefromC-bandobservedwithC-con guration,exceptthosemarkedbysigns.Thelastcolumngivestheseparationbetweenmasersandcalibrators.Somesourceshavenodataduetofailureofthetelescope.

aU-bandbU-bandcU-banddSourceeSource

dataobservedwithCcon guration.dataobservedwithAcon guration.dataobservedwithBcon guration.listedinGregory&Condon(1991).

listedinVLBAcalibratorsource(Petrovetal.2005).