DOE OSTI · 3009995
Spectroscopic Characterization of redMaPPer Galaxy Clusters with DESI
Abstract
Optical galaxy cluster identification algorithms such as redMaPPer promise to enable an array of astrophysical and cosmological studies, but suffer from biases whereby galaxies in front of and behind a galaxy cluster are mistakenly associated with the primary cluster halo. These projection effects caused by irreducible photometric redshift uncertainty must be quantified to facilitate the use of optical cluster catalogues. We present measurements of galaxy cluster projection effects and velocity dispersion using spectroscopy from the Dark Energy Spectroscopic Instrument. Our findings are as follows: we confirm that the fraction of redMaPPer putative member galaxies mistakenly associated with cluster haloes is richness dependent, being more than twice as large at low richness than high richness; we present the first spectroscopic evidence of an increase in projection effects with increasing redshift, by as much as 25 per cent from $z\sim 0.1$ to $z\sim 0.2$; moreover, we find qualitative evidence for luminosity dependence in projection effects, with fainter galaxies being more commonly far behind clusters than their bright counterparts; finally, we fit the scaling relation between measured mean spectroscopic richness and velocity dispersion, finding an implied linear scaling between spectroscopic richness and halo mass. We discuss further directions for the application of spectroscopic data sets to improve use of optically selected clusters to test cosmological models.
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Myles, J [Princeton University Department of Astrophysical Sciences, , Princeton NJ 08544 ,] (ORCID:0000000161455859), Gruen, D [Excellence Cluster ORIGINS , Boltzmannstrasse 2, D-85748 Garching ,; University Observatory, Faculty of Physics, Ludwig-Maximilians-Universität , Scheinerstr. 1, D-81677 München ,] (ORCID:0000000332707644), Jeltema, T [University of California Department of Astronomy and Astrophysics, UCO/Lick Observatory, , 1156 High Street, Santa Cruz, CA 95064 ,] (ORCID:0000000160890365), Mantz, A [Stanford University Physics Department, , Stanford, CA 93405 ,; SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, CA 94025 ,] (ORCID:0000000280311217), Allen, S [Stanford University Physics Department, , Stanford, CA 93405 ,; SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, CA 94025 ,], Fu, S [SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, CA 94025 ,] (ORCID:0000000154221958), Kremin, A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Aguilar, J [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Ahlen, S [Boston University Department of Physics, , 590 Commonwealth Avenue, Boston, MA 02215 ,], Bianchi, D [Dipartimento di Fisica ‘Aldo Pontremoli’, Università degli Studi di Milano , Via Celoria 16, I-20133 Milano ,; INAF – Osservatorio Astronomico di Brera , Via Brera 28, I-20122 Milano ,], Brooks, D [University College London Department of Physics & Astronomy, , Gower Street, London, WC1E 6BT ,], Castander, F J [Institut d’Estudis Espacials de Catalunya (IEEC) , c/ Esteve Terradas 1, Edifici RDIT, Campus PMT-UPC, E-08860 Castelldefels ,; Institute of Space Sciences, ICE-CSIC, Campus UAB , Carrer de Can Magrans s/n, E-08913 Bellaterra, Barcelona ,], Claybaugh, T [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], de la Macorra, A [Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Ciudad Universitaria , Cd. de México C. 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Campbell Rd., Richardson, TX 75080 ,], Kehoe, R [Southern Methodist University Department of Physics, , 3215 Daniel Avenue, Dallas, TX 75275 ,], Kirkby, D [University of California Department of Physics and Astronomy, , Irvine, 92697 ,], Kisner, T [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Lahav, O [University College London Department of Physics & Astronomy, , Gower Street, London, WC1E 6BT ,], Landriau, M [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Le Guillou, L [Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Sorbonne Université , CNRS/IN2P3, F-75005 Paris ,], Manera, M [Universitat Autònoma de Barcelona Departament de Física, Serra Húnter, , E-08193 Bellaterra (Barcelona) ,; Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology , Edifici Cn, Campus UAB, E-08193 Bellaterra (Barcelona) ,], Meisner, A [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,], Miquel, R [Institució Catalana de Recerca i Estudis Avançats, Passeig de Lluís Companys , 23, E-08010 Barcelona ,; Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology , Edifici Cn, Campus UAB, E-08193 Bellaterra (Barcelona) ,], Moustakas, J [Siena College Department of Physics and Astronomy, , 515 Loudon Road, Loudonville, NY 12211 ,], Nadathur, S [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building , Portsmouth, PO1 3FX ,], Newman, J A [University of Pittsburgh Department of Physics & Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), , 3941 O’Hara Street, Pittsburgh, PA 15260 ,], Palanque-Delabrouille, N [IRFU, CEA, Université Paris-Saclay , F-91191 Gif-sur-Yvette ,; Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Prada, F [Instituto de Astrofísica de Andalucía (CSIC) , Glorieta de la Astronomía, s/n, E-18008 Granada ,], Pérez-Ràfols, I [Departament de Física, EEBE, Universitat Politècnica de Catalunya , c/Eduard Maristany 10, E-08930 Barcelona ,], Rossi, G [Sejong University Department of Physics and Astronomy, , 209 Neungdong-ro, Gwangjin-gu, Seoul 05006 ,], Sanchez, E [CIEMAT, Avenida Complutense 40 , E-28040 Madrid ,], Schlegel, D [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Schubnell, M [University of Michigan Department of Physics, , 450 Church Street, Ann Arbor, MI 48109 ,; University of Michigan , 500 S. State Street, Ann Arbor, MI 48109 ,], Silber, J [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Sprayberry, D [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,], Tarlé, G [University of Michigan , 500 S. State Street, Ann Arbor, MI 48109 ,], Weaver, B A [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,], Zhou, R [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]. 2025-10-22. Spectroscopic Characterization of redMaPPer Galaxy Clusters with DESI. https://doi.org/10.1093/mnras%2Fstaf1831
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