JWST NIRSpec spectroscopy of the triply-lensed $z = 10.17$ galaxy MACS0647$-$JD

Autor: Hsiao, Tiger Yu-Yang, Abdurro'uf, Coe, Dan, Larson, Rebecca L., Jung, Intae, Mingozzi, Matilde, Dayal, Pratika, Kumari, Nimisha, Kokorev, Vasily, Vikaeus, Anton, Brammer, Gabriel, Furtak, Lukas J., Adamo, Angela, Andrade-Santos, Felipe, Antwi-Danso, Jacqueline, Bradac, Marusa, Bradley, Larry D., Broadhurst, Tom, Carnall, Adam C., Conselice, Christopher J., Diego, Jose M., Donahue, Megan, Eldridge, Jan J., Fujimoto, Seiji, Henry, Alaina, Hernandez, Svea, Hutchison, Taylor A., James, Bethan L., Norman, Colin, Park, Hyunbae, Pirzkal, Norbert, Postman, Marc, Ricotti, Massimo, Rigby, Jane R., Vanzella, Eros, Welch, Brian, Wilkins, Stephen M., Windhorst, Rogier A., Xu, Xinfeng, Zackrisson, Erik, Zitrin, Adi
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
Popis: We present JWST/NIRSpec prism spectroscopy of MACS0647-JD, the triply-lensed $z \sim 11$ candidate discovered in HST imaging and spatially resolved by JWST imaging into two components A and B. Spectroscopy of component A yields a spectroscopic redshift $z=10.17$ based on 7 detected emission lines: CIII] $\lambda\lambda$1907,1909, [OII] $\lambda$3727, [NeIII] $\lambda$3869, [NeIII] $\lambda$3968, H$\delta$ $\lambda$4101, H$\gamma$ $\lambda$4340, and [OIII] $\lambda$4363. These are the second-most distant detections of these emission lines to date, in a galaxy observed just 460 million years after the Big Bang. Based on observed and extrapolated line flux ratios we derive a gas-phase metallicity $Z =$ log(O/H) = $7.5 - 8.0$, or $(0.06 - 0.2)$ $Z_\odot$, ionization parameter log($U$) $\sim -1.9\pm0.2$, and an ionizing photon production efficiency ${\rm log}(\xi_{\rm ion})=25.2\pm0.2\,$erg$^{-1}$ Hz. The spectrum has a softened Lyman-$\alpha$ break, evidence for a strong Ly$\alpha$ damping wing, suggesting that MACS0647-JD was unable to ionize its surroundings beyond its immediate vicinity ($R_{\text{HII}} \ll 1$ pMpc). The Ly$\alpha$ damping wing also suppresses the F150W photometry, explaining the slightly overestimated photometric redshift $z = 10.6 \pm 0.3$. MACS0647-JD has a stellar mass log($M/M_\odot$) = $8.1 \pm 0.3$, including $\sim$ 6$\times 10^7 M_\odot$ in component A, most of which formed recently (within $\sim$ 20 Myr) with a star formation rate $2\pm1 M_\odot$ / yr, all within an effective radius $70\pm24\,$pc. The smaller component B ($r \sim 20$) pc is likely older ($\sim$100 Myr) with more dust ($A_V \sim 0.1$ mag), as found previously. Spectroscopy of a fainter companion galaxy C separated by a distance of \about\ 3$\,$kpc reveals a Lyman break consistent with $z = 10.17$. MACS0647-JD is likely the most distant galaxy merger known.
Comment: 22 pages, 6 figures, accepted for publication in ApJ
Databáze: arXiv