The GOGREEN Survey: A deep stellar mass function of cluster galaxies at 1.0 < z < 1.4 and the complex nature of satellite quenching

¹ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
e-mail: rvanderb@eso.org
² Department of Physics and Astronomy, The University of Kansas, 1251 Wescoe Hall Drive, Lawrence, KS 66045, USA
³ Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada
⁴ Waterloo Centre for Astrophysics, University of Waterloo, Waterloo, ON N2L 3G1, Canada
⁵ Department of Physics and Astronomy, York University, 4700, Keele Street, Toronto, ON MJ3 1P3, Canada
⁶ The Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2601, Australia
⁷ European Space Agency (ESA), European Space Astronomy Centre, Villanueva de la Cañada, 28691 Madrid, Spain
⁸ Department of Astronomy & Astrophysics, University of Toronto, Toronto, Canada
⁹ Department of Physics, McGill University, 3600 Rue University, Montréal, Québec H3P 1T3, Canada
¹⁰ South African Astronomical Observatory, PO Box 9, Observatory 7935 Cape Town, South Africa
¹¹ Centre for Space Research, North-West University, Potchefstroom, 2520 Cape Town, South Africa
¹² School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, England
¹³ INAF – Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, 34143 Trieste, Italy
¹⁴ IFPU – Institute for Fundamental Physics of the Universe, Via Beirut 2, 34014 Trieste, Italy
¹⁵ Departamento de Astronomía, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción, Concepción, Chile
¹⁶ Department of Physics and Astronomy, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA
¹⁷ Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697, USA
¹⁸ NRC-Herzberg, 5071 West Saanich Road, Victoria, British Columbia V9E2E7, Canada
¹⁹ Physics Institute, Laboratoire d’Astrophysique, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1290 Sauverny, Switzerland
²⁰ GEPI, Observatoire de Paris, Université PSL, CNRS, Place Jules Janssen, 92190 Meudon, France
²¹ Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool L3 5RF, UK
²² Department of Physics & Astronomy, Tufts University, 574 Boston Avenue Suites 304, Medford, MA 02155, USA
²³ Departamento de Ciencias Físicas, Universidad Andres Bello, Fernandez Concha 700, Las Condes 7591538, Santiago, Región Metropolitana, Chile
²⁴ Arizona State University, School of Earth and Space Exploration, Tempe, AZ 871404, USA
²⁵ MIT Kavli Institute for Astrophysics and Space Research, 70 Vassar St, Cambridge, MA 02109, USA
²⁶ INAF – Osservatorio astronomico di Padova, Vicolo Osservatorio 5, 35122 Padova, Italy
²⁷ Leiden Observatory, Leiden University, 2300 RA Leiden, The Netherlands
²⁸ Steward Observatory and Department of Astronomy, University of Arizona, Tucson, AZ 85719, USA

Received: 17 February 2020
Accepted: 20 April 2020

Abstract

We study the stellar mass functions (SMFs) of star-forming and quiescent galaxies in 11 galaxy clusters at 1.0 < z < 1.4 drawn from the Gemini Observations of Galaxies in Rich Early ENvironments (GOGREEN) survey. Based on more than 500 h of Gemini/GMOS spectroscopy and deep multi-band photometry taken with a range of observatories, we probe the SMFs down to a stellar mass limit of 10^9.7 M_⊙ (10^9.5 M_⊙ for star-forming galaxies). At this early epoch, the fraction of quiescent galaxies is already highly elevated in the clusters compared to the field at the same redshift. The quenched fraction excess (QFE) represents the fraction of galaxies that would be star-forming in the field but are quenched due to their environment. The QFE is strongly mass dependent, and increases from ∼30% at M_⋆ = 10^9.7 M_⊙ to ∼80% at M_⋆ = 10^11.0 M_⊙. Nonetheless, the shapes of the SMFs of the two individual galaxy types, star-forming and quiescent galaxies, are identical between cluster and field to high statistical precision. Nevertheless, along with the different quiescent fractions, the total galaxy SMF is also environmentally dependent, with a relative deficit of low-mass galaxies in the clusters. These results are in stark contrast with findings in the local Universe, and therefore require a substantially different quenching mode to operate at early times. We discuss these results in light of several popular quenching models.