ASTE 12CO (J = 3–2) Survey of Elliptical Galaxies

[摘要] Wereporton$$^{12}$$CO ($$J$$=3–2)observationsof15nearbyellipticalgalaxies,carriedoutwiththeASTEtelescope.Thirteenwereselectedwithoutregardtothepresenceofothertracersofcoldinterstellarmatter.COemissionwasdetectedfromthreeofthegalaxies,twoofwhichwereundetectedbyIRASat100$$mu$$m.Themoleculargasmassesrangefrom$$2.2imes10^6$$to$$4.3imes10^8M_odot$$.TheratiooftheCO (3–2)and(1–0)lines,$$R_{31}$$,hasalowervalueforellipticalgalaxiesthanforspiralgalaxies,exceptforNGC855,forwhichthevalueisclosetothemeanforspirals.ThemoleculargasinNGC855hasameandensityintherangeof300–1000cm$$^{-3}$$,adoptingatemperaturerangeof15–100K.

[学科分类] 天文学(综合)

[关键词] "galaxies: elliptical";"galaxies: ISM";"ISM: molecules";"radio lines: ISM"