JWST MIRI detections of H$alpha$ and [O III] and direct metallicity measurement of the $z=10.17$ lensed galaxy MACS0647$-$JD

JWST MIRI detections of H$alpha$ and [O III] and direct metallicity measurement of the $z=10.17$ lensed galaxy MACS0647$-$JD
Tiger Yu-Yang Hsiao, Javier ‘Alvarez-M’arquez, Dan Coe, Alejandro Crespo G’omez, Abdurro’uf, Pratika Dayal, Rebecca L. Larson, Arjan Bik, Carmen Blanco-Prieto, Luis Colina, Pablo Guillermo P’erez-Gonz’alez, Luca Costantin, Carlota Prieto-Jim’enez, Angela Adamo, Larry D. Bradley, Christopher J. Conselice, Seiji Fujimoto, Lukas J. Furtak, Taylor A. Hutchison, Bethan L. James, Yolanda Jim’enez-Teja, Intae Jung, Vasily Kokorev, Matilde Mingozzi, Colin Norman, Massimo Ricotti, Jane R. Rigby, Keren Sharon, Eros Vanzella, Brian Welch, Xinfeng Xu, Erik Zackrisson, Adi Zitrin
arXiv:2404.16200v1 Announce Type: new
Abstract: JWST spectroscopy has revolutionized our understanding of galaxies in the early universe. Covering wavelengths up to $5.3,{rm mu m}$, NIRSpec can detect rest-frame optical emission lines H$alpha$ out to $z = 7$ and [O III] to $z = 9.5$. Observing these lines in more distant galaxies requires longer wavelength spectroscopy with MIRI. Here we present MIRI MRS IFU observations of the lensed galaxy merger MACS0647$-$JD at $z = 10.165$. With exposure times of 4.2 hours in each of two bands, we detect H$alpha$ at $9sigma$, [O III]$,lambda5008$ at $11sigma$, and [O III]$,lambda4960$ at $3sigma$. Combined with previously reported NIRSpec spectroscopy that yields seven emission lines including the auroral line [O III]$,lambda4363$, we present the first direct metallicity measurement of a $z > 10$ galaxy: $12+{rm log(O/H)}= 7.79pm0.09$, or $0.13^{+0.02}_{-0.03},Z_{odot}$. This is similar to galaxies at $z sim 4 – 9$ with direct metallicity measurements, though higher than expected given the high specific star formation rate ${rm log(sSFR / yr^{-1})} = -7.4 pm 0.3$. We further constrain the ionization parameter ${rm log}(U)$ = $-1.9 pm 0.1$, ionizing photon production efficiency ${rm log}(xi_{rm ion})$ = $25.3pm0.1$, and star formation rate $5.0pm0.6,M_{odot}/{rm yr}$ within the past $10,{rm Myr}$. These observations demonstrate the combined power of JWST NIRSpec and MIRI for studying galaxies in the first $500$ million years.arXiv:2404.16200v1 Announce Type: new
Abstract: JWST spectroscopy has revolutionized our understanding of galaxies in the early universe. Covering wavelengths up to $5.3,{rm mu m}$, NIRSpec can detect rest-frame optical emission lines H$alpha$ out to $z = 7$ and [O III] to $z = 9.5$. Observing these lines in more distant galaxies requires longer wavelength spectroscopy with MIRI. Here we present MIRI MRS IFU observations of the lensed galaxy merger MACS0647$-$JD at $z = 10.165$. With exposure times of 4.2 hours in each of two bands, we detect H$alpha$ at $9sigma$, [O III]$,lambda5008$ at $11sigma$, and [O III]$,lambda4960$ at $3sigma$. Combined with previously reported NIRSpec spectroscopy that yields seven emission lines including the auroral line [O III]$,lambda4363$, we present the first direct metallicity measurement of a $z > 10$ galaxy: $12+{rm log(O/H)}= 7.79pm0.09$, or $0.13^{+0.02}_{-0.03},Z_{odot}$. This is similar to galaxies at $z sim 4 – 9$ with direct metallicity measurements, though higher than expected given the high specific star formation rate ${rm log(sSFR / yr^{-1})} = -7.4 pm 0.3$. We further constrain the ionization parameter ${rm log}(U)$ = $-1.9 pm 0.1$, ionizing photon production efficiency ${rm log}(xi_{rm ion})$ = $25.3pm0.1$, and star formation rate $5.0pm0.6,M_{odot}/{rm yr}$ within the past $10,{rm Myr}$. These observations demonstrate the combined power of JWST NIRSpec and MIRI for studying galaxies in the first $500$ million years.