학술논문
MIDIS: Strong (H beta plus [OIII]) and Ha Emitters at Redshift z similar or equal to 7-8 Unveiled with JWST NIRCam and MIRI Imaging in the Hubble eXtreme Deep Field
Document Type
Author
Rinaldi, P.; Caputi, K. I.; Costantin, L.; Gillman, S.; Iani, E.; Perez-Gonzalez, P. G.; Östlin, Göran, 1968; Colina, L.; Greve, T. R.; Noorgard-Nielsen, H. U.; Wright, G. S.; Alonso-Herrero, A.; Alvarez-Marquez, J.; Eckart, A.; Garcia-Marin, M.; Hjorth, J.; Ilbert, O.; Kendrew, S.; Labiano, A.; Le Fevre, O.; Pye, J.; Tikkanen, T.; Walter, F.; van der Werf, P.; Ward, M.; Annunziatella, M.; Azzollini, R.; Bik, Arjan; Boogaard, L.; Bosman, S. E. I.; Gomez, A. Crespo; Jermann, I.; Langeroodi, D.; Melinder, Jens, 1977; Meyer, R. A.; Moutard, T.; Peissker, F.; Topinka, M.; van Dishoeck, E.; Gudel, M.; Henning, Th.; Lagage, P. -O.; Ray, T.; Vandenbussche, B.; Waelkens, C.; Navarro-Carrera, R.; Kokorev, V.
Source
Astrophysical Journal. 952(2)
Subject
Language
English
ISSN
0004-637X
1538-4357
1538-4357
Abstract
We make use of JWST medium-band and broadband NIRCam imaging, along with ultradeep MIRI 5.6 mu m imaging, in the Hubble eXtreme Deep Field to identify prominent line emitters at z similar or equal to 7-8. Out of a total of 58 galaxies at z similar or equal to 7-8, we find 18 robust candidates ( similar or equal to 31%) for (H beta + [O III]) emitters, based on their enhanced fluxes in the F430M and F444W filters, with EW0(H beta +[O III]) similar or equal to 87-2100 angstrom. Among these emitters, 16 lie in the MIRI coverage area and 12 exhibit a clear flux excess at 5.6 mu m, indicating the simultaneous presence of a prominent Ha emission line with EW0(H alpha) similar or equal to 200-3000 angstrom. This is the first time that H alpha emission can be detected in individual galaxies at z > 7. The Ha line, when present, allows us to separate the contributions of H beta and [O III] to the (H beta +[O III]) complex and derive Ha-based star formation rates (SFRs). We find that in most cases [O III]/ H beta > 1. Instead, two galaxies have [O III]/H beta < 1, indicating that the NIRCam flux excess is mainly driven by H beta. Most prominent line emitters are very young starbursts or galaxies on their way to/from the starburst cloud. They make for a cosmic SFR density log(10)( rho(SFRH alpha) (M-circle dot yr(-1) Mpc))similar or equal to - 2.351 3 which is about a quarter of the total value (log(10)( SFR (M-circle dot yr(-1) Mpc))similar or equal to - 1.761 3 ) at z similar or equal to 7-8. Therefore, the strong Ha emitters likely had a significant role in reionization.