%0 Generic %1 kannan2022milleniumtng %A Kannan, Rahul %A Springel, Volker %A Hernquist, Lars %A Pakmor, Rüdiger %A Delgado, Ana Maria %A Hadzhiyska, Boryana %A Hernández-Aguayo, César %A Barrera, Monica %A Ferlito, Fulvio %A Bose, Sownak %A White, Simon %A Frenk, Carlos %A Smith, Aaron %A Garaldi, Enrico %D 2022 %K MilleniumTNG galaxies high redshift %T The MilleniumTNG Project: The galaxy population at $z8$ %U http://arxiv.org/abs/2210.10066 %X The early release science results from the $James Webb Space Telescope (JWST)$ have yielded an unexpected abundance of high-redshift luminous galaxies that seems to be in tension with current theories of galaxy formation. However, it is currently difficult to draw definitive conclusions form these results as the sources have not yet been spectroscopically confirmed. It is in any case important to establish baseline predictions from current state-of-the-art galaxy formation models that can be compared and contrasted with these new measurements. In this work, we use the new large-volume ($L_box740 \, cMpc$) hydrodynamic simulation of the MilleniumTNG project to make predictions for the high-redshift ($z\gtrsim8$) galaxy population and compare them to recent $JWST$ observations. We show that the simulated galaxy population is broadly consistent with observations until $z\sim10$. From $z\approx10-12$, the observations indicate a preference for a galaxy population that is largely dust-free, but is still consistent with the simulations. Beyond $z\gtrsim12$, however, our simulation results underpredict the abundance of luminous galaxies and their star-formation rates by almost an order of magnitude. This indicates either an incomplete understanding of the new $JWST$ data or a need for more sophisticated galaxy formation models that account for additional physical processes such as Population~III stars, variable stellar initial mass functions, or even deviations from the standard $Łambda$CDM model. We emphasise that any new process invoked to explain this tension should only significantly influence the galaxy population beyond $z\gtrsim10$, while leaving the successful galaxy formation predictions of the fiducial model intact below this redshift.

@misc{kannan2022milleniumtng, abstract = {The early release science results from the $\textit{James Webb Space Telescope (JWST)}$ have yielded an unexpected abundance of high-redshift luminous galaxies that seems to be in tension with current theories of galaxy formation. However, it is currently difficult to draw definitive conclusions form these results as the sources have not yet been spectroscopically confirmed. It is in any case important to establish baseline predictions from current state-of-the-art galaxy formation models that can be compared and contrasted with these new measurements. In this work, we use the new large-volume ($L_\mathrm{box}\sim 740 \, \mathrm{cMpc}$) hydrodynamic simulation of the MilleniumTNG project to make predictions for the high-redshift ($z\gtrsim8$) galaxy population and compare them to recent $\textit{JWST}$ observations. We show that the simulated galaxy population is broadly consistent with observations until $z\sim10$. From $z\approx10-12$, the observations indicate a preference for a galaxy population that is largely dust-free, but is still consistent with the simulations. Beyond $z\gtrsim12$, however, our simulation results underpredict the abundance of luminous galaxies and their star-formation rates by almost an order of magnitude. This indicates either an incomplete understanding of the new $\textit{JWST}$ data or a need for more sophisticated galaxy formation models that account for additional physical processes such as Population~III stars, variable stellar initial mass functions, or even deviations from the standard $\Lambda$CDM model. We emphasise that any new process invoked to explain this tension should only significantly influence the galaxy population beyond $z\gtrsim10$, while leaving the successful galaxy formation predictions of the fiducial model intact below this redshift.}, added-at = {2022-10-20T11:19:47.000+0200}, author = {Kannan, Rahul and Springel, Volker and Hernquist, Lars and Pakmor, Rüdiger and Delgado, Ana Maria and Hadzhiyska, Boryana and Hernández-Aguayo, César and Barrera, Monica and Ferlito, Fulvio and Bose, Sownak and White, Simon and Frenk, Carlos and Smith, Aaron and Garaldi, Enrico}, biburl = {https://www.bibsonomy.org/bibtex/2a182aeeefe321c1da1ed193056c62868/quark75}, description = {The MilleniumTNG Project: The galaxy population at $z\geq 8$}, interhash = {d4a06fa853fd6443e2ad4a936a63cf10}, intrahash = {a182aeeefe321c1da1ed193056c62868}, keywords = {MilleniumTNG galaxies high redshift}, note = {cite arxiv:2210.10066Comment: 11 pages, 7 figures, Comments welcome -- Part of the initial set of papers introducing the MilleniumTNG project. Visit www.mtng-project.org for more details}, timestamp = {2022-10-20T11:19:47.000+0200}, title = {The MilleniumTNG Project: The galaxy population at $z\geq 8$}, url = {http://arxiv.org/abs/2210.10066}, year = 2022 }