We present the average [C ii] 158 mu m emission line sizes of UV-bright star-forming galaxies at z similar to 7. Our results are derived from a stacking analysis of [C ii] 158 mu m emission lines and dust continua observed by the Atacama Large Millimeter/submillimeter Array (ALMA), taking advantage of the large program Reionization Era Bright Emission Line Survey. We find that the average [C ii] emission at z similar to 7 has an effective radius r ( e ) of 2.2 +/- 0.2 kpc. It is greater than or similar to 2x larger than the dust continuum and the rest-frame UV emission, in agreement with recently reported measurements for z less than or similar to 6 galaxies. Additionally, we compared the average [C ii] size with 4 < z < 6 galaxies observed by the ALMA Large Program to INvestigate [C ii] at Early times (ALPINE). By analyzing [C ii] sizes of 4 < z < 6 galaxies in two redshift bins, we find an average [C ii] size of r (e) = 2.2 +/- 0.2 kpc and r (e) = 2.5 +/- 0.2 kpc for z similar to 5.5 and z similar to 4.5 galaxies, respectively. These measurements show that star-forming galaxies, on average, show no evolution in the size of the [C ii] 158 mu m emitting regions at redshift between z similar to 7 and z similar to 4. This finding suggests that the star-forming galaxies could be morphologically dominated by gas over a wide redshift range.
The ALMA REBELS Survey: Average [C ii] 158 ??m Sizes of Star-forming Galaxies from z ??? 7 to z ??? 4 / Fudamoto, Y.; Smit, R.; Bowler, R. A. A.; Oesch, P. A.; Bouwens, R.; Stefanon, M.; Inami, H.; Endsley, R.; Gonzalez, V.; Schouws, S.; Stark, D.; Algera, H. S. B.; Aravena, M.; Barrufet, L.; da Cunha, E.; Dayal, P.; Ferrara, A.; Graziani, L.; Hodge, J. A.; Hygate, A. P. S.; Inoue, A. K.; Nanayakkara, T.; Pallottini, A.; Pizzati, E.; Schneider, R.; Sommovigo, L.; Sugahara, Y.; Topping, M.; van der Werf, P.; Bethermin, M.; Cassata, P.; Dessauges-Zavadsky, M.; Ibar, E.; Faisst, A. L.; Fujimoto, S.; Ginolfi, M.; Hathi, N.; Jones, G. C.; Pozzi, F.; Schaerer, D.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 934:2(2022), p. 144. [10.3847/1538-4357/ac7a47]
The ALMA REBELS Survey: Average [C ii] 158 ??m Sizes of Star-forming Galaxies from z ??? 7 to z ??? 4
P. Dayal;L. Graziani;R. Schneider;M. Ginolfi;
2022
Abstract
We present the average [C ii] 158 mu m emission line sizes of UV-bright star-forming galaxies at z similar to 7. Our results are derived from a stacking analysis of [C ii] 158 mu m emission lines and dust continua observed by the Atacama Large Millimeter/submillimeter Array (ALMA), taking advantage of the large program Reionization Era Bright Emission Line Survey. We find that the average [C ii] emission at z similar to 7 has an effective radius r ( e ) of 2.2 +/- 0.2 kpc. It is greater than or similar to 2x larger than the dust continuum and the rest-frame UV emission, in agreement with recently reported measurements for z less than or similar to 6 galaxies. Additionally, we compared the average [C ii] size with 4 < z < 6 galaxies observed by the ALMA Large Program to INvestigate [C ii] at Early times (ALPINE). By analyzing [C ii] sizes of 4 < z < 6 galaxies in two redshift bins, we find an average [C ii] size of r (e) = 2.2 +/- 0.2 kpc and r (e) = 2.5 +/- 0.2 kpc for z similar to 5.5 and z similar to 4.5 galaxies, respectively. These measurements show that star-forming galaxies, on average, show no evolution in the size of the [C ii] 158 mu m emitting regions at redshift between z similar to 7 and z similar to 4. This finding suggests that the star-forming galaxies could be morphologically dominated by gas over a wide redshift range.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
