Year: 2019
Type: article
Abstract: We present an enhanced version of the multiwavelength spectral modeling code MAGPHYS that allows the estimation of galaxy photometric redshift and physical properties (e.g., stellar mass, star formation rate, dust attenuation) simultaneously, together with robust characterization of their uncertainties. The self-consistent modeling over ultraviolet to radio wavelengths in MAGPHYS+photo - z is unique compared to standard photometric redshift codes. The broader wavelength consideration is particularly useful for breaking certain degeneracies in color versus redshift for dusty galaxies with limited observer-frame ultraviolet and optical data (or upper limits). We demonstrate the success of the code in estimating redshifts and physical properties for over 4000 infrared-detected galaxies at 0.4 < z < 6.0 in the COSMOS field with robust spectroscopic redshifts. We achieve high photo- z precision ( ), high accuracy (i.e., minimal offset biases; median(Δ z /(1 + z spec )) ≲ 0.02), and low catastrophic failure rates ( η ≃ 4%) over all redshifts. Interestingly, we find that a weak 2175 Å absorption feature in the attenuation curve models is required to remove a subtle systematic z phot offset ( ) that occurs when this feature is not included. As expected, the accuracy of derived physical properties in MAGPHYS+photo - z decreases strongly as redshift uncertainty increases. The all-in-one treatment of uncertainties afforded with this code is beneficial for accurately interpreting physical properties of galaxies in large photometric data sets. Finally, we emphasize that MAGPHYS+photo - z is not intended to replace existing photo- z codes, but rather offers flexibility to robustly interpret physical properties when spectroscopic redshifts are unavailable. The MAGPHYS+photo - z code is publicly available online.
Source: The Astrophysical Journal
Authors: A. J. Battisti, E. da Cunha, K. Grasha, M. Salvato, E. Daddi, L. Davies, S. Jin, D. Liu, E. Schinnerer, M. Vaccari
Institutions: Australian National University, ASTRO-3D, ARC Centre of Excellence for All-sky Astrophysics, The University of Western Australia, International Centre for Radio Astronomy Research, Max Planck Institute for Extraterrestrial Physics, Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Astrophysique, Instrumentation et Modélisation, Sorbonne Paris Cité, Université Paris Diderot, Universidad de La Laguna, Instituto de Astrofísica de Canarias, Nanjing University, Max Planck Institute for Astronomy, Istituto di Radioastronomia di Bologna, University of the Western Cape
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2971545996