0 Assigned ID: 3154 ----- Attempting Submission 1 (Fri Mar 25 07:51:10 GMT 2022) ----- HST Phase I Proposal 3154 successfully submitted. Receipt: # 3154-1 ----- Attempting Submission 2 (Fri Mar 25 22:40:43 GMT 2022) ----- Incorporating information from the star formation histories (SFH) of individual galaxies into traditional 'snapshots' of scaling relations will provide transformative advances in our understanding of galaxy populations and star formation over cosmic time. Over the past years, improved methods to recover SFH information applied to high-quality multi-wavelength photometric surveys have allowed for significant gains in SFH reconstruction. We propose to augment the information in the SFR-M* plane with trajectories from the derived SFHs of galaxies at 0.5<z<3 in the deepest Hubble fields (CANDELS and the Hubble Frontier Fields). To robustly measure the SFHs, we combine the outputs from 4 state-of-the-art SED fitting codes and thus quantify the modeling uncertainties in the trajectories. As a proof of concept, we compare the trajectories of real galaxies in a single CANDELS field (GOODS-S) at z~1 with predictions of two models that are capable of producing distributions in SFR-M* space identical to the real observations, but make significantly different predictions for trajectories. Trajectories in SFR-M* space allow for better matching of individual galaxies to their progenitors across different redshifts and provide novel metrics against which to evaluate predictions from state of the art cosmological simulations. This technique can also be extended to other datasets and upcoming observations from JWST, allowing us to push this analysis to 3<z<9. PI Iyer is an expert in Bayesian approaches to SED fitting applied to reconstructing star formation histories and trajectories in SFR-M* space, the focus of the science in this proposal. Importantly, Dr. Pacifici, Dr. Iyer, and Dr. Carnall are the builders of three of the four SFH-reconstruction codes that we will use in the proposed research. Dr. Tacchella is an expert on observation-theory comparisons and SED modeling, in particular regarding the SED tool Prospector. Each code has at least three or more associated publications describing the capacity of the code to accurately derive each galaxy's star formation history from multi-wavelength photometry. Co-I Gawiser is an expert in galaxy evolution and SED fitting. Co-Is Chartab, Olsen and Broussard are PhD students actively studying metrics of SFR burstiness and correlating SFHs with ancillary catalogs like galaxy environment. Co-Is Faber and Ferguson are the Co-PIs of CANDELS, one of the surveys used by this project, and experts in astrostatistics, galaxy evolution, and derivations of physical properties from SEDs. Co-I Fontana is the Project Coordinator of the ASTRODEEP program, which has produced complete Spitzer photometric catalogs for all six Frontier Fields, the other survey used by this project. Co-I Koekemoer is an expert on large scientific value-added HST mosaic datasets (having led this for CANDELS and other programs), relevant to the photometric measurements and catalogs used here. Co-I Papovich is versed in Bayesian SED modeling and a pioneer in the derivation of physical properties of high-redshift galaxies. Co-I Grogin is chief architect for several of the largest HST imaging surveys, including both CANDELS and HFF, with research focus on the host galaxies of distant lower-luminosity AGN. Co-I Koo has worked for over 3 decades on multiwavelength photometric and spectral analysis and modeling of the evolution of distant galaxy assembly, stellar populations, structure, kinematics, AGN activity, and feedback. Co-I Fazio is the PI of the Infrared Array Camera (IRAC) on the Spitzer Space Telescope and PI of the Spitzer/IRAC surveys of the CANDELS fields. Co-I Hathi is a member of the HST CANDELS and UVCANDELS teams, and has expertise in physical properties including the UV-spectral slope/dust, SFRs, and stellar masses of star-forming galaxies at high redshifts. He is also the curator of a large compilation of spectroscopic redshifts in the CANDELS fields. Co-I Lucas is a Co-I on many large HST extragalactic programs from the original HDF and HDF-S through GOODS and the HUDF, HUDF-05, CANDELS, Frontier Fields and UVCANDELS programs, and has been particularly involved in morphology-related work in those programs. Co-I Primack has expertise in semi-analytic models and simulations that can be tested with the proposed observations. Co-I Starkenburg is an expert in galaxy evolution, particularly at comparing observations to cosmological simulations. Co-I Basu-Zych is an expert at working with X-ray data & AGN. Co-I Behroozi has expertise in empirical modeling of galaxy formation and in inferring self-consistent star formation histories from observations from many redshifts. Galaxies Galaxies 0 Regular false false false false false false SUPPORTED