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| Main Authors: | , , , , , |
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| Format: | Preprint |
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2024
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2408.15194 |
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| _version_ | 1866914170409058304 |
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| author | O'Brennan, Hannah Regan, John A. Power, Chris Ward, Saoirse Brennan, John McCaffrey, Joe |
| author_facet | O'Brennan, Hannah Regan, John A. Power, Chris Ward, Saoirse Brennan, John McCaffrey, Joe |
| contents | Recent JWST observations of very early galaxies, at $\rm{z \gtrsim 10}$, have led to claims that tension exists between the sizes and luminosities of high-redshift galaxies and what is predicted by standard $Λ$CDM models. Here we use the adaptive mesh refinement code $\texttt{Enzo}$ and the N-body smoothed particle hydrodynamics code $\texttt{SWIFT}$ to compare (semi-)analytic halo mass functions against the results of direct N-body models at high redshift. In particular, our goal is to investigate the variance between standard halo mass functions derived from (semi-)analytic formulations and N-body calculations and to determine what role any discrepancy may play in driving tensions between observations and theory. We find that the difference between direct N-body calculations and (semi-) analytic halo mass function fits is less than a factor of 2 (at $\rm{z \sim 10}$) within the mass range of galaxies currently being observed by JWST, and is therefore not a dominant source of error when comparing theory and observation at high redshift. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2408_15194 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Halo mass functions at high redshift O'Brennan, Hannah Regan, John A. Power, Chris Ward, Saoirse Brennan, John McCaffrey, Joe Cosmology and Nongalactic Astrophysics Recent JWST observations of very early galaxies, at $\rm{z \gtrsim 10}$, have led to claims that tension exists between the sizes and luminosities of high-redshift galaxies and what is predicted by standard $Λ$CDM models. Here we use the adaptive mesh refinement code $\texttt{Enzo}$ and the N-body smoothed particle hydrodynamics code $\texttt{SWIFT}$ to compare (semi-)analytic halo mass functions against the results of direct N-body models at high redshift. In particular, our goal is to investigate the variance between standard halo mass functions derived from (semi-)analytic formulations and N-body calculations and to determine what role any discrepancy may play in driving tensions between observations and theory. We find that the difference between direct N-body calculations and (semi-) analytic halo mass function fits is less than a factor of 2 (at $\rm{z \sim 10}$) within the mass range of galaxies currently being observed by JWST, and is therefore not a dominant source of error when comparing theory and observation at high redshift. |
| title | Halo mass functions at high redshift |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2408.15194 |