Early Results from GLASS-JWST. XVII. Building the First Galaxies-Chapter 1. Star Formation Histories for 5 < z < 7 Galaxies

April 2023 • 2023ApJ...947L..27D

Authors • Dressler, Alan • Vulcani, Benedetta • Treu, Tommaso • Rieke, Marcia • Burns, Chris • Calabrò, Antonello • Bonchi, Andrea • Castellano, Marco • Fontana, Adriano • Leethochawalit, Nicha • Mason, Charlotte • Merlin, Emiliano • Morishita, Takahiro • Paris, Diego • Bradac, Marusa • Mercurio, Amata • Nanayakkara, Themiya • Poggianti, Bianca M. • Santini, Paola • Wang, Xin • Misselt, Karl • Stark, Daniel P. • Willmer, Christopher

Abstract • The JWST observations of high-redshift galaxies are used to measure their star formation histories-the buildup of stellar mass in the earliest galaxies. Here we use a novel analysis program, SEDz*, to compare near-IR spectral energy distributions for galaxies with redshifts 5 < z < 7 to combinations of stellar population templates evolved from z = 12. We exploit NIRCam imaging in seven wide bands covering 1-5 μm taken in the context of the GLASS-JWST-ERS program and use SEDz* to solve for well-constrained star formation histories for 24 exemplary galaxies. In this first look, we find a variety of histories, from long, continuous star formation over 5 < z < 12 to short but intense starbursts, sometimes repeating, and, most commonly, contiguous mass buildup lasting ~0.5 Myr, possibly the seeds of today's typical M* galaxies.


IPAC Authors


Takahiro Morishita

Assistant Scientist