Euclid Collaboration, R. Saglia, S. De Nicola, M. Fabricius, V. Guglielmo, J. Snigula, R. Zöller, R. Bender, J. Heidt, D. C. Masters, D. Stern, S. Paltani, A. Amara, N. Auricchio, M. Baldi, C. Bodendorf, D. Bonino, E. Branchini, M. Brescia, J. Brinchmann, S. Camera, V. Capobianco, C. Carbone, J. Carretero, M. Castellano, S. Cavuoti, R. Cledassou, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, L. Corcione, F. Courbin, M. Cropper, A. C. da Silva, H. Degaudenzi, M. Douspis, F. Dubath, C. A. J. Duncan, X. Dupac, S. Dusini, S. Farrens, M. Frailis, E. Franceschi, S. Galeotta, B. Garilli, W. Gillard, B. R. Gillis, C. Giocoli, A. Grazian, F. Grupp, S. V. H. Haugan, H. Hoekstra, W. A. Holmes, F. Hormuth, A. Hornstrup, K. Jahnke, M. Kümmel, S. Kermiche, A. Kiessling, M. Kunz, H. Kurki-Suonio, R. J. Laureijs, S. Ligori, P. B. Lilje, I. Lloro, E. Maiorano, O. Marggraf, K. Markovic, F. Marulli, R. Massey, H. J. McCracken, M. Melchior, G. Meylan, M. Moresco, L. Moscardini, E. Munari, S. M. Niemi, C. Padilla, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, S. Pires, M. Poncet, L. A. Popa, L. Pozzetti, F. Raison, A. Renzi, J. D. Rhodes, G. Riccio, E. Romelli, E. Rossetti, D. Sapone, B. Sartoris, P. Schneider, A. Secroun, G. Seidel, C. Sirignano, G. Sirri, L. Stanco, P. Tallada-Crespí, D. Tavagnacco, A. N. Taylor, I. Tereno, R. Toledo-Moreo, F. Torradeflot, I. Tutusaus, E. A. Valentijn, L. Valenziano, T. Vassallo, Y. Wang, A. Zacchei, G. Zamorani, J. Zoubian, S. Andreon, S. Bardelli, J. Graciá-Carpio, D. Maino, N. Mauri, A. Tramacere, E. Zucca, A. Alvarez Ayllon, H. Aussel, C. Baccigalupi, A. Balaguera-Antolínez, M. Ballardini, A. Biviano, M. Bolzonella, E. Bozzo, C. Burigana, R. Cabanac, A. Cappi, C. S. Carvalho, S. Casas, G. Castignani, A. Cooray, J. Coupon, H. M. Courtois, S. Davini, G. Desprez, H. Dole, J. A. Escartin, S. Escoffier, M. Farina, S. Fotopoulou, K. Ganga, J. Garcia-Bellido, K. George, F. Giacomini, G. Gozaliasl, H. Hildebrandt, I. M. Hook, O. Ilbert, V. Kansal, A. Kashlinsky, E. Keihanen, C. C. Kirkpatrick, A. Loureiro, J. F. Macías-Pérez, M. Magliocchetti, G. Mainetti, R. Maoli, M. Martinelli, N. Martinet, R. B. Metcalf, G. Morgante, S. Nadathur, A. A. Nucita, L. Patrizii, V. Popa, C. Porciani, D. Potter, A. Pourtsidou, P. Flose-Reimberg, A. G. Sánchez, Z. Sakr, M. Schirmer, E. Sefusatti, M. Sereno, J. Stadel, R. Teyssier, C. Valieri, J. Valiviita, A. Veropalumbo, M. Viel
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.
Keywords
galaxies: distances and redshifts / catalogs / surveys
Notes
The LBT is an international collaboration among institutions in the United States, Italy, and Germany. The LBT Corporation partners are: LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia
Astronomy & Astrophysics
Volume 664, Article Number A196, Number of pages 22
2022 August
