EPOCHS IV: SED Modelling Assumptions and their impact on the Stellar Mass Function at 6.5 \textless z \textless 13.5 using PEARLS and public JWST observations. Harvey, T., Conselice, C., Adams, N. J., Austin, D., Juodzbalis, I., Trussler, J., Li, Q., Ormerod, K., Ferreira, L., Duan, Q., Westcott, L., Harris, H., Bhatawdekar, R., Coe, D., Cohen, S. H., Caruana, J., Cheng, C., Driver, 9 S. P., Frye, B., Furtak, L. J., Grogin, N. A., Hathi, N. P., Holwerda, B. W., Jansen, R. A., Koekemoer, A. M., Lovell, C. J., Marshall, M. A., Nonino, M., Smail, I., Vijayan, A. P., Wilkins, S. M., Windhorst, R., Willmer, C. N. A., Yan, H., & Zitrin, A. March, 2024. arXiv:2403.03908 [astro-ph]
EPOCHS IV: SED Modelling Assumptions and their impact on the Stellar Mass Function at 6.5 \textless z \textless 13.5 using PEARLS and public JWST observations [link]Paper  abstract   bibtex   
We utilize deep JWST NIRCam observations for the first direct constraints on the Galaxy Stellar Mass Function (GSMF) at z\textgreater10. Our EPOCHS v1 sample includes 1120 galaxy candidates at 6.5\textlessz\textless13.5 taken from a consistent reduction and analysis of publicly available deep JWST NIRCam data covering the PEARLS, CEERS, GLASS, JADES GOOD-S, NGDEEP, and SMACS0723 surveys, totalling 187 arcmin2. We investigate the impact of SED fitting methods, assumed star formation histories (SFH), dust laws, and priors on galaxy masses and the resultant GSMF. Whilst our fiducial GSMF agrees with the literature at z\textless13.5, we find that the assumed SFH model has a large impact on the GSMF and stellar mass density (SMD), finding a 0.75 dex increase in the SMD at z=10.5 between a flexible non-parametric and standard parametric SFH. Overall, we find a flatter SMD evolution at z \textgreater 9 than some studies predict, suggesting a rapid buildup of stellar mass in the early Universe. We find no incompatibility between our results and those of standard cosmological models, as suggested previously, although the most massive galaxies may require a high star formation efficiency. We find that the 'Little Red Dot' galaxies dominate the z=7 GSMF at high-masses, necessitating a better understanding of the relative contributions of AGN and stellar emission. We show that assuming a theoretically motivated top-heavy IMF reduces stellar mass by 0.5 dex without affecting fit quality, but our results remain consistent with existing cosmological models with a standard IMF.
@misc{harvey_epochs_2024,
	title = {{EPOCHS} {IV}: {SED} {Modelling} {Assumptions} and their impact on the {Stellar} {Mass} {Function} at 6.5 {\textless} z {\textless} 13.5 using {PEARLS} and public {JWST} observations},
	shorttitle = {{EPOCHS} {IV}},
	url = {http://arxiv.org/abs/2403.03908},
	abstract = {We utilize deep JWST NIRCam observations for the first direct constraints on the Galaxy Stellar Mass Function (GSMF) at z{\textgreater}10. Our EPOCHS v1 sample includes 1120 galaxy candidates at 6.5{\textless}z{\textless}13.5 taken from a consistent reduction and analysis of publicly available deep JWST NIRCam data covering the PEARLS, CEERS, GLASS, JADES GOOD-S, NGDEEP, and SMACS0723 surveys, totalling 187 arcmin2. We investigate the impact of SED fitting methods, assumed star formation histories (SFH), dust laws, and priors on galaxy masses and the resultant GSMF. Whilst our fiducial GSMF agrees with the literature at z{\textless}13.5, we find that the assumed SFH model has a large impact on the GSMF and stellar mass density (SMD), finding a 0.75 dex increase in the SMD at z=10.5 between a flexible non-parametric and standard parametric SFH. Overall, we find a flatter SMD evolution at z {\textgreater} 9 than some studies predict, suggesting a rapid buildup of stellar mass in the early Universe. We find no incompatibility between our results and those of standard cosmological models, as suggested previously, although the most massive galaxies may require a high star formation efficiency. We find that the 'Little Red Dot' galaxies dominate the z=7 GSMF at high-masses, necessitating a better understanding of the relative contributions of AGN and stellar emission. We show that assuming a theoretically motivated top-heavy IMF reduces stellar mass by 0.5 dex without affecting fit quality, but our results remain consistent with existing cosmological models with a standard IMF.},
	urldate = {2024-03-07},
	publisher = {arXiv},
	author = {Harvey, Thomas and Conselice, Christopher and Adams, Nathan J. and Austin, Duncan and Juodzbalis, Ignas and Trussler, James and Li, Qiong and Ormerod, Katherine and Ferreira, Leonardo and Duan, Qiao and Westcott, Lewi and Harris, Honor and Bhatawdekar, Rachana and Coe, Dan and Cohen, Seth H. and Caruana, Joseph and Cheng, Cheng and Driver, 9 Simon P. and Frye, Brenda and Furtak, Lukas J. and Grogin, Norman A. and Hathi, Nimish P. and Holwerda, Benne W. and Jansen, Rolf A. and Koekemoer, Anton M. and Lovell, Christopher J. and Marshall, Madeline A. and Nonino, Mario and Smail, Ian and Vijayan, Aswin P. and Wilkins, Stephen M. and Windhorst, Rogier and Willmer, Christopher N. A. and Yan, Haojing and Zitrin, Adi},
	month = mar,
	year = {2024},
	note = {arXiv:2403.03908 [astro-ph]},
	keywords = {Astrophysics - Astrophysics of Galaxies},
}

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