학술논문
Spatially-resolved H$\alpha$ and ionizing photon production efficiency in the lensed galaxy MACS1149-JD1 at a redshift of 9.11
Document Type
Working Paper
Author
Álvarez-Márquez, J.; Colina, L.; Gómez, A. Crespo; Rinaldi, P.; Melinder, J.; Östlin, G.; Annunziatella, M.; Labiano, A.; Bik, A.; Bosman, S.; Greve, T. R.; Wright, G.; Alonso-Herrero, A.; Boogaard, L.; Azollini, R.; Caputi, K. I.; Costantin, L.; Eckart, A.; GarcÍa-MarÍn, M.; Gillman, S.; Hjorth, J.; Iani, E.; Ilbert, O.; Jermann, I.; Langeroodi, D.; Meyer, R.; Peissker, F.; Pérez-González, P.; Pye, J. P.; Tikkanen, T.; Topinka, M.; van der Werf, P.; Walter, F.; Henning, Th.; Ray, T.
Source
A&A 686, A85 (2024)
Subject
Language
Abstract
We present MIRI/JWST medium-resolution spectroscopy (MRS) and imaging (MIRIM) of the lensed galaxy MACS1149-JD1 at a redshift of $z$=9.1092$\pm$0.0002 (Universe age about 530 Myr). We detect, for the first time, spatially resolved H$\alpha$ emission in a galaxy at a redshift above nine. The structure of the H$\alpha$ emitting gas consists of two clumps, S and N. The total H$\alpha$ luminosity implies an instantaneous star-formation of 5.3$\pm$0.4 $M_{\odot}$ yr$^{-1}$ for solar metallicities. The ionizing photon production efficiency, $\log(\zeta_\mathrm{ion})$, shows a spatially resolved structure with values of 25.55$\pm$0.03, 25.47$\pm$0.03, and 25.91$\pm$0.09 Hz erg$^{-1}$ for the integrated galaxy, and clumps S and N, respectively. The H$\alpha$ rest-frame equivalent width, EW$_{0}$(H$\alpha$), is 726$^{+660}_{-182}$ \'Angstrom for the integrated galaxy, but presents extreme values of 531$^{+300}_{-96}$ \'Angstrom and $\geq$1951 \'Angstrom for clumps S and N, respectively. The spatially resolved ionizing photon production efficiency is within the range of values measured in galaxies at redshift above six, and well above the canonical value (25.2$\pm$0.1 Hz erg$^{-1}$). The extreme difference of EW$_{0}$(H$\alpha$) for Clumps S and N indicates the presence of a recent (<5 Myrs) burst in clump N and a star formation over a larger period of time (e.g., $\sim$50 Myr) in clump S. Finally, clump S and N show very different H$\alpha$ kinematics with velocity dispersions of 56$\pm$4 km s$^{-1}$ and 113$\pm$33 km s$^{-1}$, likely indicating the presence of outflows or increased turbulence in the clump N. The dynamical mass, $M_\mathrm{dyn}$= (2.4$\pm$0.5)$\times$10$^{9}$ $M_{\odot}$, is within the range measured with the spatially resolved [OIII]88$\mu$m line.
Comment: 11 pages, 6 figures, published version in A&A
Comment: 11 pages, 6 figures, published version in A&A