Dressler, AlanAlanDresslerVULCANI, BenedettaBenedettaVULCANITreu, TommasoTommasoTreuRieke, MarciaMarciaRiekeBurns, ChrisChrisBurnsCALABRO', AntonelloAntonelloCALABRO'BONCHI, AndreaAndreaBONCHICASTELLANO, MarcoMarcoCASTELLANOFONTANA, AdrianoAdrianoFONTANALeethochawalit, NichaNichaLeethochawalitMason, CharlotteCharlotteMasonMERLIN, EmilianoEmilianoMERLINMorishita, TakahiroTakahiroMorishitaPARIS, DiegoDiegoPARISBradac, MarusaMarusaBradacMERCURIO, AmataAmataMERCURIONanayakkara, ThemiyaThemiyaNanayakkaraPOGGIANTI, Bianca MariaBianca MariaPOGGIANTISANTINI, PaolaPaolaSANTINIWang, XinXinWangMisselt, KarlKarlMisseltStark, Daniel P.Daniel P.StarkWillmer, ChristopherChristopherWillmer2025-03-072025-03-0720232041-8205http://hdl.handle.net/20.500.12386/36517The 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.STAMPAenArticle10.3847/2041-8213/ac9ebb2-s2.0-85153889801https://api.elsevier.com/content/abstract/scopus_id/85153889801https://iopscience.iop.org/article/10.3847/2041-8213/ac9ebbFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation