The eROSITA Final Equatorial-Depth Survey (eFEDS)

A complete census of X-ray properties of Subaru Hyper Suprime-Cam weak lensing shear-selected clusters in the eFEDS footprint

¹ Max Planck Institut für extraterrestrische Physik, Giessenbachstraße 1, 85748 Garching, Germany
e-mail: mramos@mpe.mpg.de
² Research Center for the Early Universe, University of Tokyo, Tokyo 113-0033, Japan
³ Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
⁴ Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), University of Tokyo, Chiba 277-8582, Japan
⁵ National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
⁶ SOKENDAI (The Graduate University for Advanced Studies), Mitaka, Tokyo 181-8588, Japan
⁷ Tsung-Dao Lee Institute, and Key Laboratory for Particle Physics, Astrophysics and Cosmology, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, PR China
⁸ Department of Astronomy, School of Physics and Astronomy, and Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai Jiao Tong University, Shanghai 200240, PR China
⁹ Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), No. 1, Sect. 4, Roosevelt Road, Taipei 10617, Taiwan
¹⁰ Physics Program, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi- Hiroshima, Hiroshima 739-8526, Japan
¹¹ Hiroshima Astrophysical Science Center, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
¹² Core Research for Energetic Universe, Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
¹³ Argelander-Institut für Astronomie (AIfA), Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany
¹⁴ IRAP, Université de Toulouse, CNRS, UPS, CNES, Toulouse, France
¹⁵ Faculty of Physics, Ludwig-Maximilians-Universität, Scheinerstr. 1, 81679 Munich, Germany
¹⁶ Division of Physics and Astrophysical Science, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
¹⁷ Kobayashi-Maskawa Institute for the Origin of Particles and theUniverse (KMI), Nagoya University, Nagoya 464-8602, Japan
¹⁸ Institute for Advanced Research, Nagoya University, Nagoya 464-8601, Japan
¹⁹ The Inter University Centre for Astronomy and Astrophysics, Ganeshkhind, Pune 411007, India
²⁰ Department of Physics, Nara Women’s University, Kitauoyanishimachi, Nara 630-8506, Japan

Received: 13 September 2021
Accepted: 17 December 2021

Abstract

Context. The eFEDS survey is a proof-of-concept mini-survey designed to demonstrate the survey science capabilities of SRG/eROSITA. It covers an area of 140 deg² where ~540 galaxy clusters have been detected out to a redshift of 1.3. The eFEDS field is partly embedded in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) S19A data release, which covers ~510 deg², containing approximately 36 million galaxies. This galaxy catalogue has been used to construct a sample of ~180 shear-selected galaxy clusters. The common area to both surveys covers about 90 deg², making it an ideal region to study galaxy clusters selected in different ways.

Aims. The aim of this work is to investigate the effects of selection methods in the galaxy cluster detection by comparing the X-ray selected, eFEDS, and the shear-selected, HSC-SSP S19A, galaxy cluster samples. There are 25 shear-selected clusters in the eFEDS fooprint.

Methods. The relation between X-ray bolometric luminosity and weak-lensing mass is investigated (L_bol - M relation), comparing this relation derived from a shear-selected cluster sample to the relation obtained from an X-ray selected sample. Moreover, the dynamical state of the shear-selected clusters is investigated and compared to the X-ray selected sample using X-ray morphological parameters and galaxy distribution.

Results. The normalisation of the L_bol – M relation of the X-ray selected and shear-selected samples is consistent within 1σ-. Moreover, the dynamical state and merger fraction of the shear-selected clusters is not different from the X-ray selected ones. Four shear-selected clusters are undetected in X-rays. A close inspection reveals that one is the result of projection effects, while the other three have an X-ray flux below the ultimate eROSITA detection limit. Finally, 43% of the shear-selected clusters lie in superclusters.

Conclusions. Our results indicate that the scaling relation between X-ray bolometric luminosity and true cluster mass of the shear-selected cluster sample is consistent with the eFEDS sample. There is no significant population of X-ray underluminous clusters, indicating that X-ray selected cluster samples are complete and can be used as an accurate cosmological probe.