SPIDERS: Overview of the X-ray galaxy cluster follow-up and the final spectroscopic data release

CLERC, N.; KIRKPATRICK, C.C.; FINOGUENOV, A.; CAPASSO, R.; COMPARAT, J.; DAMSTED, S.; FURNELL, K.; KUKKOLA, A.E.; IDER CHITHAM, J.; MERLONI, A.; SALVATO, M.; GUEGUEN, A.; DWELLY, T.; COLLINS, C.; SARO, A.; ERFANIANFAR, G.; SCHNEIDER, D.P.; BROWNSTEIN, J.; MAMON, G.A.; PADILLA, N.; JULLO, E.; BIZYAEV, D.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020 vol. 497 p. 3976 - 3992

0035-8711

SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a large spectroscopic programme for X-ray selected galaxy clusters as part of the Sloan Digital Sky Survey-IV (SDSS-IV). We describe the final data set in the context of SDSS Data Release 16 (DR16): The survey overall characteristics, final targeting strategies, achieved completeness, and spectral quality, with special emphasis on its use as a galaxy cluster sample for cosmology applications. SPIDERS now consists of about 27 000 new optical spectra of galaxies selected within 4000 photometric red sequences, each associated with an X-ray source. The excellent spectrograph efficiency and a robust analysis pipeline yield a spectroscopic redshift measurement success rate exceeding 98 per cent, with a median velocity accuracy of 20 km s-1 (at z = 0.2). Using the catalogue of 2740 X-ray galaxy clusters confirmed with DR16 spectroscopy, we reveal the 3D map of the galaxy cluster distribution in the observable Universe up to z ∼0.6. We highlight the homogeneity of the member galaxy spectra among distinct regions of the galaxy cluster phase space. Aided by accurate spectroscopic redshifts and by a model of the sample selection effects, we compute the galaxy cluster X-ray luminosity function and we present its lack of evolution up to z = 0.6. Finally we discuss the prospects of forthcoming large multiplexed spectroscopic programmes dedicated to follow up the next generation of all-sky X-ray source catalogues.