| Autor: |
Bakx, Tom J L C, Algera, Hiddo S B, Venemans, Bram, Sommovigo, Laura, Fujimoto, Seiji, Carniani, Stefano, Hagimoto, Masato, Hashimoto, Takuya, Inoue, Akio K, Salak, Dragan, Serjeant, Stephen, Vallini, Livia, Eales, Stephen, Ferrara, Andrea, Fudamoto, Yoshinobu, Imamura, Chihiro, Inoue, Shigeki, Knudsen, Kirsten K, Matsuo, Hiroshi, Sugahara, Yuma |
| Předmět: |
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| Zdroj: |
Monthly Notices of the Royal Astronomical Society; Aug2024, Vol. 532 Issue 2, p2270-2288, 19p |
| Abstrakt: |
We present Atacama Large Millimetre/submillimetre Array (ALMA) observations of the [O iii ] 88 |$\mu {\rm m}$| emission of a sample of thirteen galaxies at |$z = 6$| to 7.6 selected as [C ii ]-emitting companion sources of quasars. To disentangle the origins of the luminous Oxygen line in the |$z\, \gt\, 6$| Universe, we looked at emission-line galaxies that are selected through an excellent star-formation tracer [C ii ] with star-formation rates between 9 and 162 |$\rm {\rm M}_{\odot }\,yr^{-1}$|. Direct observations reveal [O iii ] emission in just a single galaxy (|$L_\mathrm{[O\, {\small III}]}/L_\mathrm{[C\, {\small II}]}$| |$\, = 2.3$|), and a stacked image shows no [O iii ] detection, providing deep upper limits on the |$L_\mathrm{[O\, {\small III}]}/L_\mathrm{[C\, {\small II}]}$| ratios in the |$z \gt 6$| Universe (|$L_\mathrm{[O\, {\small III}]}/L_\mathrm{[C\, {\small II}]}$| |$\, \lt 1.2$| at |$3 \sigma$|). While the fidelity of this sample is high, no obvious optical/near-infrared counterpart is seen in the JWST imaging available for four galaxies. Additionally accounting for low- z CO emitters, line stacking shows that our sample-wide result remains robust: The enhanced |$L_\mathrm{[O\, {\small III}]}/L_\mathrm{[C\, {\small II}]}$| reported in the first billion years of the Universe is likely due to the selection towards bright, blue Lyman-break galaxies with high surface star-formation rates or young stellar populations. The deep upper limit on the rest-frame 90 μ m continuum emission (|$\lt 141 \mu$| Jy at |$3 \sigma$|), implies a low average dust temperature (|$T_\mathrm{dust} \lesssim 30\,$| K) and high-dust mass (|$M_\mathrm{dust} \sim 10^8\, \mathrm{M}_\odot$|). As more normal galaxies are explored in the early Universe, synergy between JWST and ALMA is fundamental to further investigate the ISM properties of the a broad range of samples of high- z galaxies. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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