Kavli Affiliate: James J. Bock
| First 5 Authors: Richard M. Feder, Daniel C. Masters, Bomee Lee, James J. Bock, Yi-Kuan Chiang
| Summary:
We simulate galaxy properties and redshift estimation for SPHEREx, the next
NASA Medium Class Explorer. To make robust models of the galaxy population and
test spectro-photometric redshift performance for SPHEREx, we develop a set of
synthetic spectral energy distributions based on detailed fits to COSMOS2020
photometry spanning 0.1-8 micron. Given that SPHEREx obtains low-resolution
spectra, emission lines will be important for some fraction of galaxies. Here
we expand on previous work, using better photometry and photometric redshifts
from COSMOS2020, and tight empirical relations to predict robust emission line
strengths and ratios. A second galaxy catalog derived from the GAMA survey is
generated to ensure the bright ($m_{AB}<18$ in the i-band) sample is
representative over larger areas. Using template fitting to estimate
photometric continuum redshifts, we forecast redshift recovery of 19 million
galaxies over 30000 sq. deg. with $sigma_z<0.003(1+z)$, 445 million with
$sigma_z<0.1(1+z)$ and 810 million with $sigma_z<0.2(1+z)$. We also find
through idealized tests that emission line information from spectrally dithered
flux measurements can yield redshifts with accuracy beyond that implied by the
naive SPHEREx channel resolution, motivating the development of a hybrid
continuum-line redshift estimation approach.
| Search Query: ArXiv Query: search_query=au:”James J. Bock”&id_list=&start=0&max_results=3