Статья

The COSMOS2015 galaxy stellar mass function

I. DavidzonAix-Marseille Univ., CNRS, LAM, Laboratoire d'Astrophysique de Marseille, Marseille, FranceO. IlbertAix-Marseille Univ., CNRS, LAM, Laboratoire d'Astrophysique de Marseille, Marseille, FranceC. LaigleSub-department of Astrophysics, Department of Physics, Univer-sity of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UKJ. CouponDepartment of Astronomy, University of Geneva, Ch. d'Ecogia 16, 1290 Versoix, SwitzerlandH. J. McCrackenSorbonne Universits, UPMC University ParisI. DelvecchioDepartment of Physics, University of Zagreb, Bijenika cesta 32, 10002 Zagreb, CroatiaDaniel MastersInfrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USAP. CapakInfrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USABau-Ching HsiehAcademia Sinica Institute of Astronomy and Astrophysics, PO Box 23-141, 10617 Taipei, Taiwan, PR ChinaO. Le FèvreAix-Marseille Univ., CNRS, LAM, Laboratoire d'Astrophysique de Marseille, Marseille, FranceL. TresseCentre de Recherche Astrophysique de Lyon, Universit de Lyon,M. BétherminAix-Marseille Univ., CNRS, LAM, Laboratoire d'Astrophysique de Marseille, Marseille, FranceYu-Yen ChangCEA Paris-SaclayAndreas L. FaisstInfrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USAE. Le Floc’hLaboratoire AIM Paris-Saclay, UMR 7158, CEA, CNRS, Université Paris VII, CE-SACLAY, Bât. 709, 91191 Gif-sur-Yvette, FranceCharles L. SteinhardtDark Cosmology Centre, Niels Bohr Institute, Copenhagen University, Juliane Maries Vej 30, 2100 Copenhagen O, DenmarkSune ToftDark Cosmology Centre, Niels Bohr Institute, Copenhagen University, Juliane Maries Vej 30, 2100 Copenhagen O, DenmarkH. AusselLaboratoire AIM Paris-Saclay, UMR 7158, CEA, CNRS, Universit Paris VII, CE-SACLAY, Bt. 709, 91191 Gif-sur-Yvette, FranceC. DuboisAix-Marseille Univ., CNRS, LAM, Laboratoire d'Astrophysique de Marseille, Marseille, FranceG. HasingerM. SalvatoMax-Planck-Institut fr extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, GermanyD. B. SandersN. Z. ScovilleCahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125, USAJ. D. SilvermanKavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, The University of Tokyo, Kashiwa, 277-8583 Chiba, Japan

2017en

ABI

Аннотация

We measure the stellar mass function (SMF) and stellar mass density of galaxies in the COSMOS field up to z ~ 6. We select them in the near-IR bands of the COSMOS2015 catalogue, which includes ultra-deep photometry from UltraVISTA-DR2, SPLASH, and Subaru/Hyper Suprime-Cam. At z > 2.5 we use new precise photometric redshifts with error σ z = 0.03(1 + z ) and an outlier fraction of 12%, estimated by means of the unique spectroscopic sample of COSMOS (~100 000 spectroscopic measurements in total, more than one thousand having robust z spec > 2.5). The increased exposure time in the DR2, along with our panchromatic detection strategy, allow us to improve the completeness at high z with respect to previous UltraVISTA catalogues (e.g. our sample is >75% complete at 10 10 ℳ ⊙ and z = 5). We also identify passive galaxies through a robust colour–colour selection, extending their SMF estimate up to z = 4. Our work provides a comprehensive view of galaxy-stellar-mass assembly between z = 0.1 and 6, for the first time using consistent estimates across the entire redshift range. We fit these measurements with a Schechter function, correcting for Eddington bias. We compare the SMF fit with the halo mass function predicted from ΛCDM simulations, finding that at z > 3 both functions decline with a similar slope in thehigh-mass end. This feature could be explained assuming that mechanisms quenching star formation in massive haloes become less effective at high redshifts; however further work needs to be done to confirm this scenario. Concerning the SMF low-mass end, it shows a progressive steepening as it moves towards higher redshifts, with α decreasing from -1.47 +0.02 -0.02 at z ≃ 0.1 to -2.11 +0.30 -0.13 at z ≃ 5. This slope depends on the characterisation of the observational uncertainties, which is crucial to properly remove the Eddington bias. We show that there is currently no consensus on the method to quantify such errors: different error models result in different best-fit Schechter parameters.

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Идентификаторы

DOI: 10.1051/0004-6361/201730419

Цитирования и источники

Цитирований: 1Использованных источников: 0

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