We report the detection of [O i] 145.5 μm in the BR 1202-0725 system, a compact group at z = 4.7 consisting of a quasar (QSO), a submillimeter-bright galaxy (SMG), and three faint Lyα emitters. By taking into account the previous detections and upper limits, the [O i] /[C ii] line ratios of the now five known high-z galaxies are higher than or on the high end of the observed values in local galaxies ([O i] /[C ii] ⪆ 0.13). The high [O i] /[C ii] ratios and the joint analysis with previous detection of [N ii] lines for both of the QSO and the SMG suggest the presence of warm and dense neutral gas in these highly star-forming galaxies. This is further supported by new CO (12-11) line detections and a comparison with cosmological simulations. There is a possible positive correlation between the [N ii] 122/205 line ratio and the [O i] /[C ii] ratio when all local and high-z sources are taken into account, indicating that the denser the ionized gas, the denser and warmer the neutral gas (or vice versa). The detection of the [O i] line in the BR 1202-0725 system with a relatively short amount of integration with Atacama Large Millimeter/submillimeter Array (ALMA) demonstrates the great potential of this line as a dense gas tracer for high-z galaxies.
Dense and Warm Neutral Gas in BR 1202-0725 at z = 4.7 as Traced by the [O I] 145 μm Line / Lee M.M.; Nagao T.; De Breuck C.; Carniani S.; Cresci G.; Hatsukade B.; Kawabe R.; Kohno K.; Maiolino R.; Mannucci F.; Marconi A.; Nakanishi K.; Troncoso P.; Umehata H.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - ELETTRONICO. - 913:(2021), pp. 41-49. [10.3847/1538-4357/abe7ea]
Dense and Warm Neutral Gas in BR 1202-0725 at z = 4.7 as Traced by the [O I] 145 μm Line
Carniani S.;Cresci G.;Maiolino R.;Mannucci F.;Marconi A.;
2021
Abstract
We report the detection of [O i] 145.5 μm in the BR 1202-0725 system, a compact group at z = 4.7 consisting of a quasar (QSO), a submillimeter-bright galaxy (SMG), and three faint Lyα emitters. By taking into account the previous detections and upper limits, the [O i] /[C ii] line ratios of the now five known high-z galaxies are higher than or on the high end of the observed values in local galaxies ([O i] /[C ii] ⪆ 0.13). The high [O i] /[C ii] ratios and the joint analysis with previous detection of [N ii] lines for both of the QSO and the SMG suggest the presence of warm and dense neutral gas in these highly star-forming galaxies. This is further supported by new CO (12-11) line detections and a comparison with cosmological simulations. There is a possible positive correlation between the [N ii] 122/205 line ratio and the [O i] /[C ii] ratio when all local and high-z sources are taken into account, indicating that the denser the ionized gas, the denser and warmer the neutral gas (or vice versa). The detection of the [O i] line in the BR 1202-0725 system with a relatively short amount of integration with Atacama Large Millimeter/submillimeter Array (ALMA) demonstrates the great potential of this line as a dense gas tracer for high-z galaxies.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.