Euclid preparation XX. The Complete Calibration of the Color–Redshift Relation survey: LBT observations and data releas

Saglia, R.; De Nicola, S.; Fabricius, M.; Guglielmo, V.; Snigula, J.; Zöller, R.; Bender, R.; Heidt, J.; Masters, D.; Stern, D.; Paltani, S.; Amara, A.; Auricchio, N.; Baldi, M.; Bodendorf, C.; Bonino, D.; Branchini, E.; Brescia, M.; Brinchmann, J.; Camera, S.; Capobianco, V.; Carbone, C.; Carretero, J.; Castellano, M.; Cavuoti, S.; Cledassou, R.; Congedo, G.; Conselice, C.J.; Conversi, L.; Copin, Y.; Corcione, L.; Courbin, F.; Cropper, M.; Da Silva, A.; Degaudenzi, H.; Douspis, M.; Dubath, F.; Duncan, C.A.J.; Dupac, X.; Dusini, S.; Farrens, S.; Frailis, M.; Franceschi, E.; Galeotta, S.; Garilli, B.; Gillard, W.; Gillis, B.; Giocoli, C.; Grazian, A.; Grupp, F.; Haugan, S.V.H.; Hoekstra, H.; Holmes, W.; Hormuth, F.; Hornstrup, A.; Jahnke, K.; Kümmel, M.; Kermiche, S.; Kiessling, A.; Kunz, M.; Kurki-Suonio, H.; Laureijs, R.; Ligori, S.; Lilje, P.B.; Lloro, I.; Maiorano, E.; Marggraf, O.; Markovic, K.; Marulli, F.; Massey, R.; McCracken, H.J.; Melchior, M.; Meylan, G.; Moresco, M.; Moscar...

Abstract

The Complete Calibration of the Color–Redshift Relation survey (C3R2) is a spectroscopic program designed to empirically calibrate the galaxy color–redshift relation to the Euclid depth (IE = 24.5), a key ingredient for the success of Stage IV dark energy projects based on weak lensing cosmology. A spectroscopic calibration sample that is as representative as possible of the galaxies in the Euclid weak lensing sample is being collected, selecting galaxies from a self-organizing map (SOM) representation of the galaxy color space. Here, we present the results of a near-infrared H- and K-band spectroscopic campaign carried out using the LUCI instruments at the LBT. For a total of 251 galaxies, we present new highly reliable redshifts in the 1.3 ≤ z ≤ 1.7 and 2 ≤ z ≤ 2.7 ranges. The newly-determined redshifts populate 49 SOM cells that previously contained no spectroscopic measurements and almost twice the occupation numbers of an additional 153 SOM cells. A final optical ground-based observational effort is needed to calibrate the missing cells, in particular in the redshift range 1.7 ≤ z ≤ 2.7, which lack spectroscopic calibration. In the end, Euclid itself will deliver telluric-free near-IR spectra that can complete the calibration.

Citation

Saglia, R., De Nicola, S., Fabricius, M., Guglielmo, V., Snigula, J., Zöller, R., …Viel, M. (2022). Euclid preparation XX. The Complete Calibration of the Color–Redshift Relation survey: LBT observations and data releas. Astronomy & Astrophysics, 664, Article A196. https://doi.org/10.1051/0004-6361/202243604

• Journal Article Type: Article
• Acceptance Date: Jun 1, 2022
• Online Publication Date: Aug 30, 2022
• Publication Date: 2022-08
• Deposit Date: Oct 11, 2022
• Publicly Available Date: Oct 11, 2022
• Journal: Astronomy & Astrophysics
• Print ISSN: 0004-6361
• Electronic ISSN: 1432-0746
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 664
• Article Number: A196
• DOI: https://doi.org/10.1051/0004-6361/202243604
• Public URL: https://durham-repository.worktribe.com/output/1189153