title: Detection of molecular gas in the quasar BR1202 - 0725 at redshift z = 4.69.
abstract: Although great efforts have been made to locate molecular gas--the material out of which stars form--in the early Universe, there have been only two firm detections at high redshift. Both are gravitationally lensed objects at redshift z approximately = 2.5 (refs 9-14). Here we report the detection of CO emission from the radio-quiet quasar BR1202 - 0725, which is at redshift z = 4.69. From the observed CO luminosity, we estimate that almost 10(11) solar masses of molecular hydrogen are associated with the quasar; this is comparable to the stellar mass of a present-day luminous galaxy. Our results suggest that BR1202 - 0725 is a massive galaxy, in which the gas is largely concentrated in the central region, and that is currently undergoing a large burst of star formation.
authors.affiliation: Department of Astronomy, Kyoto University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ohta
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: K
authors.initials: K
authors.lastname: Nakanishi
authors.forename: K
authors.initials: K
authors.lastname: Kohno
authors.forename: M
authors.initials: M
authors.lastname: Akiyama
authors.forename: R
authors.initials: R
authors.lastname: Kawabe
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D002248:Carbon Monoxide / Q000032:analysis*; D005118:Extraterrestrial Environment; D006859:Hydrogen / Q000032:analysis; D013055:Spectrophotometry, Infrared
chemical_list: D002248:Carbon Monoxide; D006859:Hydrogen