A multi-line ammonia survey of the Galactic center region with the Tsukuba 32 m telescope. I. Observations and data

摘要

WepresentsurveydataofsixNH3(J,K)=(1,1),(2,2),(3,3),(4,4),(5,5),and(6,6)lines,simultaneouslyobservedwiththeTsukuba32a€‰mtelescope,inthemainpartofthecentralmolecularzoneoftheGalaxy.Thetotalnumberofon-sourcepositionswas2655.ThethreelowertransitionsweredetectedwithS/N3at2323positions(93%ofalltheon-sourcepositions).Among2323,theS/Na€‰'sof(J,K)=(4,4),(5,5),and(6,6)exceeded3.0at1426(54%),1150(43%),and1359(51%)positions,respectively.Simultaneousobservationsofthelinesenabledustoaccuratelyderiveintensityratioswithlesssystematicerrors.Boltzmannplotsindicatethattherearetwotemperaturecomponents:cold(a??20a€‰K)andwarm(a??100a€‰K).TypicalintensityratiosofTmb(2,2)/Tmb(1,1),Tmb(4,4)/Tmb(2,2),Tmb(5,5)/Tmb(4,4),andTmb(6,6)/Tmb(3,3)were0.71,0.45,0.65,and0.17,respectively.Theselineratioscorrespondtothediversityoftherotationaltemperature,whichresultsfrommixingofthetwotemperaturecomponents.