%0 Generic %1 carnall2023massive %A Carnall, A. C. %A McLure, R. J. %A Dunlop, J. S. %A McLeod, D. J. %A Wild, V. %A Cullen, F. %A Magee, D. %A Begley, R. %A Cimatti, A. %A Donnan, C. T. %A Hamadouche, M. L. %A Jewell, S. M. %A Walker, S. %D 2023 %K Early Galaxy Massive %T A massive quiescent galaxy at redshift 4.658 %U http://arxiv.org/abs/2301.11413 %X We report the spectroscopic confirmation of a massive quiescent galaxy, GS-9209 at a new redshift record of $z=4.658$, just 1.25 Gyr after the Big Bang, using new deep continuum observations from JWST NIRSpec. From our full-spectral-fitting analysis, we find that this galaxy formed its stellar population over a $\simeq200$ Myr period, approximately $600-800$ Myr after the Big Bang ($z_form=7.3\pm0.2$), before quenching at $z_quench=6.7\pm0.3$. GS-9209 demonstrates unambiguously that massive galaxy formation was already well underway within the first billion years of cosmic history, with this object having reached a stellar mass of log$_10(M_*/M_ødot) > 10.3$ by $z=7$. This galaxy also clearly demonstrates that the earliest onset of galaxy quenching was no later than $\simeq800$ Myr after the Big Bang. We estimate the iron abundance and $\alpha$-enhancement, finding Fe/H $= -0.97^+0.06_-0.07$ and $\alpha$/Fe $= 0.67^+0.25_-0.15$, suggesting the stellar mass vs iron abundance relation at $z\simeq7$, when this object formed most of its stars, was $\simeq0.4$ dex lower than at $z\simeq3.5$. Whilst its spectrum is dominated by stellar emission, GS-9209 also exhibits broad H$\alpha$ emission, indicating that it hosts an active galactic nucleus (AGN), for which we measure a black-hole mass of log$_10(M_\bullet/M_ødot) = 8.7\pm0.1$. Although large-scale star formation in GS-9209 has been quenched for almost half a billion years, the significant integrated quantity of accretion implied by this large black-hole mass suggests AGN feedback plausibly played a significant role in quenching star formation in this galaxy. GS-9209 is also extremely compact, with an effective radius of just $215\pm20$ parsecs. This intriguing object offers perhaps our deepest insight yet into massive galaxy formation and quenching during the first billion years of cosmic history.

@misc{carnall2023massive, abstract = {We report the spectroscopic confirmation of a massive quiescent galaxy, GS-9209 at a new redshift record of $z=4.658$, just 1.25 Gyr after the Big Bang, using new deep continuum observations from JWST NIRSpec. From our full-spectral-fitting analysis, we find that this galaxy formed its stellar population over a $\simeq200$ Myr period, approximately $600-800$ Myr after the Big Bang ($z_\rm{form}=7.3\pm0.2$), before quenching at $z_\rm{quench}=6.7\pm0.3$. GS-9209 demonstrates unambiguously that massive galaxy formation was already well underway within the first billion years of cosmic history, with this object having reached a stellar mass of log$_{10}(M_*/\rm{M}_\odot) > 10.3$ by $z=7$. This galaxy also clearly demonstrates that the earliest onset of galaxy quenching was no later than $\simeq800$ Myr after the Big Bang. We estimate the iron abundance and $\alpha$-enhancement, finding [Fe/H] $= -0.97^{+0.06}_{-0.07}$ and [$\alpha$/Fe] $= 0.67^{+0.25}_{-0.15}$, suggesting the stellar mass vs iron abundance relation at $z\simeq7$, when this object formed most of its stars, was $\simeq0.4$ dex lower than at $z\simeq3.5$. Whilst its spectrum is dominated by stellar emission, GS-9209 also exhibits broad H$\alpha$ emission, indicating that it hosts an active galactic nucleus (AGN), for which we measure a black-hole mass of log$_{10}(M_\bullet/\rm{M}_\odot) = 8.7\pm0.1$. Although large-scale star formation in GS-9209 has been quenched for almost half a billion years, the significant integrated quantity of accretion implied by this large black-hole mass suggests AGN feedback plausibly played a significant role in quenching star formation in this galaxy. GS-9209 is also extremely compact, with an effective radius of just $215\pm20$ parsecs. This intriguing object offers perhaps our deepest insight yet into massive galaxy formation and quenching during the first billion years of cosmic history.}, added-at = {2023-01-31T07:41:15.000+0100}, author = {Carnall, A. C. and McLure, R. J. and Dunlop, J. S. and McLeod, D. J. and Wild, V. and Cullen, F. and Magee, D. and Begley, R. and Cimatti, A. and Donnan, C. T. and Hamadouche, M. L. and Jewell, S. M. and Walker, S.}, biburl = {https://www.bibsonomy.org/bibtex/2abb5840a079574a0c6255bdf87d9ce50/quark75}, description = {A massive quiescent galaxy at redshift 4.658}, interhash = {d42ddd7116acf54a473ff99a21abe71a}, intrahash = {abb5840a079574a0c6255bdf87d9ce50}, keywords = {Early Galaxy Massive}, note = {cite arxiv:2301.11413Comment: 24 pages, 4 figures, submitted to Nature}, timestamp = {2023-01-31T07:41:15.000+0100}, title = {A massive quiescent galaxy at redshift 4.658}, url = {http://arxiv.org/abs/2301.11413}, year = 2023 }