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MAGPHYS+photo-z: Constraining the Physical Properties of Galaxies with Unknown Redshifts

Battisti, Andrew; da Cunha, Elisabete; Grasha, Kathryn; Salvato, Mara; Daddi, E.; Davies, L. J. M.; Jin, S.; Liu, D. Z.; Schinnerer, E.; Vaccari, M.

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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...[Show more]

dc.contributor.authorBattisti, Andrew
dc.contributor.authorda Cunha, Elisabete
dc.contributor.authorGrasha, Kathryn
dc.contributor.authorSalvato, Mara
dc.contributor.authorDaddi, E.
dc.contributor.authorDavies, L. J. M.
dc.contributor.authorJin, S.
dc.contributor.authorLiu, D. Z.
dc.contributor.authorSchinnerer, E.
dc.contributor.authorVaccari, M.
dc.date.accessioned2020-09-17T03:22:42Z
dc.identifier.issn0004-637X
dc.identifier.urihttp://hdl.handle.net/1885/210600
dc.description.abstractWe 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 (sD + z z 1  0.04 ( ) spec ), high accuracy (i.e., minimal offset biases; median(Δz/(1 + zspec))  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 zphot offset (zphot spec –z  -0.03) 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.
dc.description.sponsorshipE. d.C. gratefully acknowledges the Australian Research Council as the recipient of a Future Fellowship (project FT150100079). Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project No. CE170100013.
dc.format.mimetypeapplication/pdf
dc.language.isoen_AU
dc.publisherIOP Publishing
dc.rights© 2019. The American Astronomical Society
dc.sourceThe Astrophysical Journal
dc.titleMAGPHYS+photo-z: Constraining the Physical Properties of Galaxies with Unknown Redshifts
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume882
dc.date.issued2019
local.identifier.absfor020103 - Cosmology and Extragalactic Astronomy
local.identifier.absfor080306 - Open Software
local.identifier.ariespublicationu3102795xPUB5207
local.publisher.urlhttp://iopscience.iop.org/0004-637X
local.type.statusPublished Version
local.contributor.affiliationBattisti, Andrew, College of Science, ANU
local.contributor.affiliationda Cunha, Elisabete, College of Science, ANU
local.contributor.affiliationGrasha, Kathryn, College of Science, ANU
local.contributor.affiliationSalvato, Mara, Max-Planck-Institut fur Plasma Physik and Excellence Cluster
local.contributor.affiliationDaddi, E., DSM-CNRS-Universite Paris Diderot
local.contributor.affiliationDavies, L.J.M., The University of Western Australia
local.contributor.affiliationJin, S., Nanjing University
local.contributor.affiliationLiu, D Z, Max Planck Institute for Astronomy
local.contributor.affiliationSchinnerer, E., Max Planck Institut fur Astronomie
local.contributor.affiliationVaccari, M, University of the Western Cape
local.description.embargo2037-12-31
dc.relationhttp://purl.org/au-research/grants/arc/FT150100079
dc.relationhttp://purl.org/au-research/grants/arc/CE170100013
local.bibliographicCitation.issue1
local.bibliographicCitation.startpage1
local.bibliographicCitation.lastpage21
local.identifier.doi10.3847/1538-4357/ab345d
local.identifier.absseo970108 - Expanding Knowledge in the Information and Computing Sciences
local.identifier.absseo970102 - Expanding Knowledge in the Physical Sciences
dc.date.updated2020-06-23T00:54:43Z
local.identifier.scopusID2-s2.0-85072326279
CollectionsANU Research Publications

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