Big Three Dragons: Molecular Gas in a Bright Lyman-break Galaxy at z = 7.15
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Big Three Dragons : Molecular Gas in a Bright Lyman-break Galaxy at z = 7.15. / Hashimoto, Takuya; Inoue, Akio K.; Sugahara, Yuma; Fudamoto, Yoshinobu; Fujimoto, Seiji; Knudsen, K. K.; Matsuo, Hiroshi; Tamura, Yoichi; Yamanaka, Satoshi; Harikane, Yuichi; Kuno, Nario; Ono, Yoshiaki; Salak, Dragan; Ishii, Nozomi.
In: Astrophysical Journal, Vol. 952, No. 1, 48, 18.07.2023.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Big Three Dragons
T2 - Molecular Gas in a Bright Lyman-break Galaxy at z = 7.15
AU - Hashimoto, Takuya
AU - Inoue, Akio K.
AU - Sugahara, Yuma
AU - Fudamoto, Yoshinobu
AU - Fujimoto, Seiji
AU - Knudsen, K. K.
AU - Matsuo, Hiroshi
AU - Tamura, Yoichi
AU - Yamanaka, Satoshi
AU - Harikane, Yuichi
AU - Kuno, Nario
AU - Ono, Yoshiaki
AU - Salak, Dragan
AU - Ishii, Nozomi
N1 - Publisher Copyright: © 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/7/18
Y1 - 2023/7/18
N2 - We report Atacama Large Millimeter/submillimeter Array Band 3 observations of CO(6−5), CO(7−6), and [C i](2−1) in B14-65666 (“Big Three Dragons”), one of the brightest Lyman-break galaxies at z > 7 in the rest-frame ultraviolet continuum, far-infrared continuum, and emission lines of [O iii] 88 μm and [C ii] 158 μm. CO(6−5), CO(7−6), and [C i](2−1), whose 3σ upper limits on the luminosities are approximately 40 times fainter than the [C ii] luminosity, are all not detected. The L [C II]/L CO(6-5) and L [C II]/L CO(7-6) ratios are higher than the typical ratios obtained in dusty star-forming galaxies or quasar host galaxies at similar redshifts, and they may suggest a lower gas density in the photodissociated region in B14-65666. By using the (1) [C ii] luminosity, (2) dust mass-to-gas mass ratio, and (3) a dynamical mass estimate, we find that the molecular gas mass (M mol) is (0.05-11) × 1010 M ⊙. This value is consistent with the upper limit inferred from the nondetection of mid-J CO and [C i](2−1). Despite the large uncertainty in M mol, we estimate a molecular gas-to-stellar mass ratio (μ gas) of 0.65-140 and a gas depletion time (τ dep) of 2.5-550 Myr; these values are broadly consistent with those of other high-redshift galaxies. B14-65666 could be an ancestor of a passive galaxy at z ≳ 4 if no gas is fueled from outside the galaxy.
AB - We report Atacama Large Millimeter/submillimeter Array Band 3 observations of CO(6−5), CO(7−6), and [C i](2−1) in B14-65666 (“Big Three Dragons”), one of the brightest Lyman-break galaxies at z > 7 in the rest-frame ultraviolet continuum, far-infrared continuum, and emission lines of [O iii] 88 μm and [C ii] 158 μm. CO(6−5), CO(7−6), and [C i](2−1), whose 3σ upper limits on the luminosities are approximately 40 times fainter than the [C ii] luminosity, are all not detected. The L [C II]/L CO(6-5) and L [C II]/L CO(7-6) ratios are higher than the typical ratios obtained in dusty star-forming galaxies or quasar host galaxies at similar redshifts, and they may suggest a lower gas density in the photodissociated region in B14-65666. By using the (1) [C ii] luminosity, (2) dust mass-to-gas mass ratio, and (3) a dynamical mass estimate, we find that the molecular gas mass (M mol) is (0.05-11) × 1010 M ⊙. This value is consistent with the upper limit inferred from the nondetection of mid-J CO and [C i](2−1). Despite the large uncertainty in M mol, we estimate a molecular gas-to-stellar mass ratio (μ gas) of 0.65-140 and a gas depletion time (τ dep) of 2.5-550 Myr; these values are broadly consistent with those of other high-redshift galaxies. B14-65666 could be an ancestor of a passive galaxy at z ≳ 4 if no gas is fueled from outside the galaxy.
U2 - 10.3847/1538-4357/acdd5c
DO - 10.3847/1538-4357/acdd5c
M3 - Journal article
AN - SCOPUS:85165638078
VL - 952
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 48
ER -
ID: 361380932