TY - JOUR

T1 - Candidate Massive Galaxies at z~4 in the Dark Energy Survey

AU - Guarnieri, Pierandrea

AU - Maraston, Claudia

AU - Thomas, Daniel

AU - Pforr, Janine

AU - Gonzalez-Perez, Violeta

AU - Etherington, James

AU - Carlsen, Joakim

AU - Morice-Atkinson, Xan

AU - Conselice, Christopher J.

AU - Gschwend, Julia

AU - Kind, Matias Carrasco

AU - Abbott, Tim

AU - Allam, Sahar

AU - Brooks, David

AU - Burke, David

AU - Rosell, Aurelio Carnero

AU - Carretero, Jorge

AU - Cunha, Carlos

AU - ďAndrea, Chris

AU - Costa, Luiz da

AU - Vincente, Juan De

AU - DePoy, Darren

AU - Diehl, H. Thomas

AU - Doel, Peter

AU - Frieman, Josh

AU - Garcia-Bellido, Juan

AU - Gruen, Daniel

AU - Gutierrez, Gaston

AU - Hanley, Dominic

AU - Hollowood, Devon

AU - Honscheid, Klaus

AU - James, David

AU - Jeltema, Tesla

AU - Kuehn, Kyler

AU - Lima, Marcos

AU - Maia, Marcio A. G.

AU - Marshall, Jennifer

AU - Martini, Paul

AU - Melchior, Peter

AU - Menanteau, Felipe

AU - Miquel, Ramon

AU - Malagon, Andres Plazas

AU - Richardson, Samuel

AU - Romer, Kathy

AU - Sanchez, Eusebio

AU - Scarpine, Vic

AU - Schindler, Rafe

AU - Sevilla, Ignacio

AU - Smith, Mathew

AU - Soares-Santos, Marcelle

AU - Sobreira, Flavia

AU - Suchyta, Eric

AU - Tarle, Gregory

AU - Walker, Alistair

AU - Wester, William

N1 - This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Pierandrea Guarnieri, Claudia Maraston, Daniel Thomas, Janine Pforr, Violeta Gonzalez-Perez, et al ; Candidate massive galaxies at z ∼ 4 in the Dark Energy Survey, Monthly Notices of the Royal Astronomical Society, Volume 483, Issue 3, 1 March 2019, Pages 3060–3081, https://doi.org/10.1093/mnras/sty3305 is available online at: https://academic.oup.com/mnras/article/483/3/3060/5232382

PY - 2019/3/1

Y1 - 2019/3/1

N2 - Using stellar population models, we predicted that the Dark Energy Survey (DES) - due to its special combination of area (5000 deg. sq.) and depth ($i = 24.3$) - would be in the position to detect massive ($\gtrsim 10^{11}$ M$_{\odot}$) galaxies at $z \sim 4$. We confront those theoretical calculations with the first $\sim 150$ deg. sq. of DES data reaching nominal depth. From a catalogue containing $\sim 5$ million sources, $\sim26000$ were found to have observed-frame $g-r$ vs $r-i$ colours within the locus predicted for $z \sim 4$ massive galaxies. We further removed contamination by stars and artefacts, obtaining 606 galaxies lining up by the model selection box. We obtained their photometric redshifts and physical properties by fitting model templates spanning a wide range of star formation histories, reddening and redshift. Key to constrain the models is the addition, to the optical DES bands $g$, $r$, $i$, $z$, and $Y$, of near-IR $J$, $H$, $K_{s}$ data from the Vista Hemisphere Survey. We further applied several quality cuts to the fitting results, including goodness of fit and a unimodal redshift probability distribution. We finally select 233 candidates whose photometric redshift probability distribution function peaks around $z\sim4$, have high stellar masses ($\log($M$^{*}$/M$_{\odot})\sim 11.7$ for a Salpeter IMF) and ages around 0.1 Gyr, i.e. formation redshift around 5. These properties match those of the progenitors of the most massive galaxies in the local universe. This is an ideal sample for spectroscopic follow-up to select the fraction of galaxies which is truly at high redshift. These initial results and those at the survey completion, which we shall push to higher redshifts, will set unprecedented constraints on galaxy formation, evolution, and the re-ionisation epoch.

AB - Using stellar population models, we predicted that the Dark Energy Survey (DES) - due to its special combination of area (5000 deg. sq.) and depth ($i = 24.3$) - would be in the position to detect massive ($\gtrsim 10^{11}$ M$_{\odot}$) galaxies at $z \sim 4$. We confront those theoretical calculations with the first $\sim 150$ deg. sq. of DES data reaching nominal depth. From a catalogue containing $\sim 5$ million sources, $\sim26000$ were found to have observed-frame $g-r$ vs $r-i$ colours within the locus predicted for $z \sim 4$ massive galaxies. We further removed contamination by stars and artefacts, obtaining 606 galaxies lining up by the model selection box. We obtained their photometric redshifts and physical properties by fitting model templates spanning a wide range of star formation histories, reddening and redshift. Key to constrain the models is the addition, to the optical DES bands $g$, $r$, $i$, $z$, and $Y$, of near-IR $J$, $H$, $K_{s}$ data from the Vista Hemisphere Survey. We further applied several quality cuts to the fitting results, including goodness of fit and a unimodal redshift probability distribution. We finally select 233 candidates whose photometric redshift probability distribution function peaks around $z\sim4$, have high stellar masses ($\log($M$^{*}$/M$_{\odot})\sim 11.7$ for a Salpeter IMF) and ages around 0.1 Gyr, i.e. formation redshift around 5. These properties match those of the progenitors of the most massive galaxies in the local universe. This is an ideal sample for spectroscopic follow-up to select the fraction of galaxies which is truly at high redshift. These initial results and those at the survey completion, which we shall push to higher redshifts, will set unprecedented constraints on galaxy formation, evolution, and the re-ionisation epoch.

KW - astro-ph.GA

U2 - 10.1093/mnras/sty3305

DO - 10.1093/mnras/sty3305

M3 - Journal article

VL - 483

SP - 3060

EP - 3081

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 3

ER -