FRESCO: The Paschen-$alpha$ Star Forming Sequence at Cosmic Noon
Chloe Neufeld, Pieter van Dokkum, Yasmeen Asali, Alba Covelo-Paz, Joel Leja, Jamie Lin, Jorryt Matthee, Pascal A. Oesch, Naveen A. Reddy, Irene Shivaei, Katherine E. Whitaker, Stijn Wuyts, Gabriel Brammer, Danilo Marchesini, Michael V. Maseda, Rohan P. Naidu, Erica J. Nelson, Anna Velichko, Andrea Weibel, Mengyuan Xiao
arXiv:2404.10816v1 Announce Type: new
Abstract: We present results from the JWST First Reionization Epoch Spectroscopically Complete Observations survey (FRESCO) on the star forming sequence of galaxies at $1.09.5 M_odot$ that are lower than found in many earlier studies by up to 0.6 dex, but in good agreement with recent results obtained with the Prospector fitting framework. The difference log(SFR(Pa$alpha$)-SFR(Prospector)) is -0.09 $pm$ 0.04 dex at $10^{10-11} M_odot$. We also measure the empirical relation between Paschen-$alpha$ luminosity and rest-frame H band magnitude and find that the scatter is only 0.04 dex lower than that of the SFR-M* relation and is much lower than the systematic differences among relations in the literature due to various methods of converting observed measurements to physical properties. We additionally identify examples of sources — that, with standard cutoffs via the UVJ diagram, would be deemed quiescent — with significant, typically extended, Paschen-$alpha$ emission. Our results may be indicative of the potential unification of methods used to derive the star forming sequence with careful selection of star forming galaxies and independent star formation rate and stellar mass indicators.arXiv:2404.10816v1 Announce Type: new
Abstract: We present results from the JWST First Reionization Epoch Spectroscopically Complete Observations survey (FRESCO) on the star forming sequence of galaxies at $1.09.5 M_odot$ that are lower than found in many earlier studies by up to 0.6 dex, but in good agreement with recent results obtained with the Prospector fitting framework. The difference log(SFR(Pa$alpha$)-SFR(Prospector)) is -0.09 $pm$ 0.04 dex at $10^{10-11} M_odot$. We also measure the empirical relation between Paschen-$alpha$ luminosity and rest-frame H band magnitude and find that the scatter is only 0.04 dex lower than that of the SFR-M* relation and is much lower than the systematic differences among relations in the literature due to various methods of converting observed measurements to physical properties. We additionally identify examples of sources — that, with standard cutoffs via the UVJ diagram, would be deemed quiescent — with significant, typically extended, Paschen-$alpha$ emission. Our results may be indicative of the potential unification of methods used to derive the star forming sequence with careful selection of star forming galaxies and independent star formation rate and stellar mass indicators.