Cosmos photometric redshifts with 30-bands for 2-deg2

O. Ilbert; P. Capak; M. Salvato; H. Aussel; H. J. McCracken; D. B. Sanders; N. Scoville; J. Kartaltepe; S. Arnouts; E. Le Floc'H; B. Mobasher; Y. Taniguchi; F. Lamareille; A. Leauthaud; S. Sasaki; D. Thompson; M. Zamojski; G. Zamorani; S. Bardelli; M. Bolzonella; A. Bongiorno; M. Brusa; K. I. Caputi; C. M. Carollo; T. Contini; R. Cook; G. Coppa; O. Cucciati; S. De La Torre; L. De Ravel; P. Franzetti; B. Garilli; G. Hasinger; A. Iovino; P. Kampczyk; J. P. Kneib; C. Knobel; K. Kovac; J. F. Le Borgne; V. Le Brun; O. Le Fèvre; S. Lilly; D. Looper; C. Maier; V. Mainieri; Y. Mellier; M. Mignoli; T. Murayama; R. Pellò; Y. Peng; E. Pérez-Montero; A. Renzini; E. Ricciardelli; D. Schiminovich; M. Scodeggio; Y. Shioya; J. Silverman; J. Surace; M. Tanaka; L. Tasca; L. Tresse; D. Vergani; E. Zucca

doi:10.1088/0004-637X/690/2/1236

Cosmos photometric redshifts with 30-bands for 2-deg²

O. Ilbert, P. Capak, M. Salvato, H. Aussel, H. J. McCracken, D. B. Sanders, N. Scoville, J. Kartaltepe, S. Arnouts, E. Le Floc'H, B. Mobasher, Y. Taniguchi, F. Lamareille, A. Leauthaud, S. Sasaki, D. Thompson, M. Zamojski, G. Zamorani, S. Bardelli, M. BolzonellaA. Bongiorno, M. Brusa, K. I. Caputi, C. M. Carollo, T. Contini, R. Cook, G. Coppa, O. Cucciati, S. De La Torre, L. De Ravel, P. Franzetti, B. Garilli, G. Hasinger, A. Iovino, P. Kampczyk, J. P. Kneib, C. Knobel, K. Kovac, J. F. Le Borgne, V. Le Brun, O. Le Fèvre, S. Lilly, D. Looper, C. Maier, V. Mainieri, Y. Mellier, M. Mignoli, T. Murayama, R. Pellò, Y. Peng, E. Pérez-Montero, A. Renzini, E. Ricciardelli, D. Schiminovich, M. Scodeggio, Y. Shioya, J. Silverman, J. Surace, M. Tanaka, L. Tasca, L. Tresse, D. Vergani, E. Zucca

SCI - Astronomy

Research output: Contribution to journal › Article › peer-review

957 Citations (Scopus)

Abstract

We present accurate photometric redshifts (photo-z) in the 2-deg ² COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrowbands covering the UV (Galaxy Evolution Explorer), visible near-IR (NIR; Subaru, Canada-France-Hawaii Telescope (CFHT), United Kingdom Infrared Telescope, and National Optical Astronomy Observatory), and mid-IR (Spitzer/IRAC). A χ² template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from the Very Large Telescope Visible Multi-Object Spectrograph and the Keck Deep Extragalactic Imaging Multi-Object Spectrograph. We develop and implement a new method which accounts for the contributions from emission lines ([OII], Hβ, Hα, and Lyα) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e., Δz = z _s - z _p) indicates a dispersion of at i ⁺ _AB < 22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHT Legacy Survey, and the Classifying Object by Medium-Band Observations-17 survey fields. At fainter magnitudes i ⁺ _AB < 24 and z < 1.25, the accuracy is . The deep NIR and Infrared Array Camera coverage enables the photo-z to be extended to z 2, albeit with a lower accuracy ( at i ⁺ _AB 24). The redshift distribution of large magnitude-selected samples is derived and the median redshift is found to range from z _m = 0.66 at 22 < i ⁺ _AB < 22.5 to z _m = 1.06 at 24.5 < i ⁺ _AB < 25. At i ⁺ _AB < 26.0, the multiwavelength COSMOS catalog includes approximately 607,617 objects. The COSMOS-30 photo-z enables the full exploitation of this survey for studies of galaxy and large-scale structure evolution at high redshift.

Original language	English
Pages (from-to)	1236-1249
Number of pages	14
Journal	Astrophysical Journal
Volume	690
Issue number	2
DOIs	https://doi.org/10.1088/0004-637X/690/2/1236
Publication status	Published - 2009

Keywords

Galaxies: distances and redshifts
Galaxies: evolution
Galaxies: formation

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

Access to Document

10.1088/0004-637X/690/2/1236

Cite this

Ilbert, O., Capak, P., Salvato, M., Aussel, H., McCracken, H. J., Sanders, D. B., Scoville, N., Kartaltepe, J., Arnouts, S., Le Floc'H, E., Mobasher, B., Taniguchi, Y., Lamareille, F., Leauthaud, A., Sasaki, S., Thompson, D., Zamojski, M., Zamorani, G., Bardelli, S., ... Zucca, E. (2009). Cosmos photometric redshifts with 30-bands for 2-deg². Astrophysical Journal, 690(2), 1236-1249. https://doi.org/10.1088/0004-637X/690/2/1236

Ilbert, O, Capak, P, Salvato, M, Aussel, H, McCracken, HJ, Sanders, DB, Scoville, N, Kartaltepe, J, Arnouts, S, Le Floc'H, E, Mobasher, B, Taniguchi, Y, Lamareille, F, Leauthaud, A, Sasaki, S, Thompson, D, Zamojski, M, Zamorani, G, Bardelli, S, Bolzonella, M, Bongiorno, A, Brusa, M, Caputi, KI, Carollo, CM, Contini, T, Cook, R, Coppa, G, Cucciati, O, De La Torre, S, De Ravel, L, Franzetti, P, Garilli, B, Hasinger, G, Iovino, A, Kampczyk, P, Kneib, JP, Knobel, C, Kovac, K, Le Borgne, JF, Le Brun, V, Le Fèvre, O, Lilly, S, Looper, D, Maier, C, Mainieri, V, Mellier, Y, Mignoli, M, Murayama, T, Pellò, R, Peng, Y, Pérez-Montero, E, Renzini, A, Ricciardelli, E, Schiminovich, D, Scodeggio, M, Shioya, Y, Silverman, J, Surace, J, Tanaka, M, Tasca, L, Tresse, L, Vergani, D & Zucca, E 2009, 'Cosmos photometric redshifts with 30-bands for 2-deg²', Astrophysical Journal, vol. 690, no. 2, pp. 1236-1249. https://doi.org/10.1088/0004-637X/690/2/1236

@article{4f9a81e0a84145ada582b2fda692ef93,

title = "Cosmos photometric redshifts with 30-bands for 2-deg2",

abstract = "We present accurate photometric redshifts (photo-z) in the 2-deg 2 COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrowbands covering the UV (Galaxy Evolution Explorer), visible near-IR (NIR; Subaru, Canada-France-Hawaii Telescope (CFHT), United Kingdom Infrared Telescope, and National Optical Astronomy Observatory), and mid-IR (Spitzer/IRAC). A χ2 template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from the Very Large Telescope Visible Multi-Object Spectrograph and the Keck Deep Extragalactic Imaging Multi-Object Spectrograph. We develop and implement a new method which accounts for the contributions from emission lines ([OII], Hβ, Hα, and Lyα) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e., Δz = z s - z p) indicates a dispersion of at i + AB < 22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHT Legacy Survey, and the Classifying Object by Medium-Band Observations-17 survey fields. At fainter magnitudes i + AB < 24 and z < 1.25, the accuracy is . The deep NIR and Infrared Array Camera coverage enables the photo-z to be extended to z 2, albeit with a lower accuracy ( at i + AB 24). The redshift distribution of large magnitude-selected samples is derived and the median redshift is found to range from z m = 0.66 at 22 < i + AB < 22.5 to z m = 1.06 at 24.5 < i + AB < 25. At i + AB < 26.0, the multiwavelength COSMOS catalog includes approximately 607,617 objects. The COSMOS-30 photo-z enables the full exploitation of this survey for studies of galaxy and large-scale structure evolution at high redshift.",

keywords = "Galaxies: distances and redshifts, Galaxies: evolution, Galaxies: formation",

author = "O. Ilbert and P. Capak and M. Salvato and H. Aussel and McCracken, {H. J.} and Sanders, {D. B.} and N. Scoville and J. Kartaltepe and S. Arnouts and {Le Floc'H}, E. and B. Mobasher and Y. Taniguchi and F. Lamareille and A. Leauthaud and S. Sasaki and D. Thompson and M. Zamojski and G. Zamorani and S. Bardelli and M. Bolzonella and A. Bongiorno and M. Brusa and Caputi, {K. I.} and Carollo, {C. M.} and T. Contini and R. Cook and G. Coppa and O. Cucciati and {De La Torre}, S. and {De Ravel}, L. and P. Franzetti and B. Garilli and G. Hasinger and A. Iovino and P. Kampczyk and Kneib, {J. P.} and C. Knobel and K. Kovac and {Le Borgne}, {J. F.} and {Le Brun}, V. and {Le F{\`e}vre}, O. and S. Lilly and D. Looper and C. Maier and V. Mainieri and Y. Mellier and M. Mignoli and T. Murayama and R. Pell{\`o} and Y. Peng and E. P{\'e}rez-Montero and A. Renzini and E. Ricciardelli and D. Schiminovich and M. Scodeggio and Y. Shioya and J. Silverman and J. Surace and M. Tanaka and L. Tasca and L. Tresse and D. Vergani and E. Zucca",

year = "2009",

doi = "10.1088/0004-637X/690/2/1236",

language = "English",

volume = "690",

pages = "1236--1249",

journal = "Astrophysical Journal",

issn = "0004-637X",

number = "2",

}

TY - JOUR

T1 - Cosmos photometric redshifts with 30-bands for 2-deg2

AU - Ilbert, O.

AU - Capak, P.

AU - Salvato, M.

AU - Aussel, H.

AU - McCracken, H. J.

AU - Sanders, D. B.

AU - Scoville, N.

AU - Kartaltepe, J.

AU - Arnouts, S.

AU - Le Floc'H, E.

AU - Mobasher, B.

AU - Taniguchi, Y.

AU - Lamareille, F.

AU - Leauthaud, A.

AU - Sasaki, S.

AU - Thompson, D.

AU - Zamojski, M.

AU - Zamorani, G.

AU - Bardelli, S.

AU - Bolzonella, M.

AU - Bongiorno, A.

AU - Brusa, M.

AU - Caputi, K. I.

AU - Carollo, C. M.

AU - Contini, T.

AU - Cook, R.

AU - Coppa, G.

AU - Cucciati, O.

AU - De La Torre, S.

AU - De Ravel, L.

AU - Franzetti, P.

AU - Garilli, B.

AU - Hasinger, G.

AU - Iovino, A.

AU - Kampczyk, P.

AU - Kneib, J. P.

AU - Knobel, C.

AU - Kovac, K.

AU - Le Borgne, J. F.

AU - Le Brun, V.

AU - Le Fèvre, O.

AU - Lilly, S.

AU - Looper, D.

AU - Maier, C.

AU - Mainieri, V.

AU - Mellier, Y.

AU - Mignoli, M.

AU - Murayama, T.

AU - Pellò, R.

AU - Peng, Y.

AU - Pérez-Montero, E.

AU - Renzini, A.

AU - Ricciardelli, E.

AU - Schiminovich, D.

AU - Scodeggio, M.

AU - Shioya, Y.

AU - Silverman, J.

AU - Surace, J.

AU - Tanaka, M.

AU - Tasca, L.

AU - Tresse, L.

AU - Vergani, D.

AU - Zucca, E.

PY - 2009

Y1 - 2009

N2 - We present accurate photometric redshifts (photo-z) in the 2-deg 2 COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrowbands covering the UV (Galaxy Evolution Explorer), visible near-IR (NIR; Subaru, Canada-France-Hawaii Telescope (CFHT), United Kingdom Infrared Telescope, and National Optical Astronomy Observatory), and mid-IR (Spitzer/IRAC). A χ2 template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from the Very Large Telescope Visible Multi-Object Spectrograph and the Keck Deep Extragalactic Imaging Multi-Object Spectrograph. We develop and implement a new method which accounts for the contributions from emission lines ([OII], Hβ, Hα, and Lyα) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e., Δz = z s - z p) indicates a dispersion of at i + AB < 22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHT Legacy Survey, and the Classifying Object by Medium-Band Observations-17 survey fields. At fainter magnitudes i + AB < 24 and z < 1.25, the accuracy is . The deep NIR and Infrared Array Camera coverage enables the photo-z to be extended to z 2, albeit with a lower accuracy ( at i + AB 24). The redshift distribution of large magnitude-selected samples is derived and the median redshift is found to range from z m = 0.66 at 22 < i + AB < 22.5 to z m = 1.06 at 24.5 < i + AB < 25. At i + AB < 26.0, the multiwavelength COSMOS catalog includes approximately 607,617 objects. The COSMOS-30 photo-z enables the full exploitation of this survey for studies of galaxy and large-scale structure evolution at high redshift.

AB - We present accurate photometric redshifts (photo-z) in the 2-deg 2 COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrowbands covering the UV (Galaxy Evolution Explorer), visible near-IR (NIR; Subaru, Canada-France-Hawaii Telescope (CFHT), United Kingdom Infrared Telescope, and National Optical Astronomy Observatory), and mid-IR (Spitzer/IRAC). A χ2 template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from the Very Large Telescope Visible Multi-Object Spectrograph and the Keck Deep Extragalactic Imaging Multi-Object Spectrograph. We develop and implement a new method which accounts for the contributions from emission lines ([OII], Hβ, Hα, and Lyα) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e., Δz = z s - z p) indicates a dispersion of at i + AB < 22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHT Legacy Survey, and the Classifying Object by Medium-Band Observations-17 survey fields. At fainter magnitudes i + AB < 24 and z < 1.25, the accuracy is . The deep NIR and Infrared Array Camera coverage enables the photo-z to be extended to z 2, albeit with a lower accuracy ( at i + AB 24). The redshift distribution of large magnitude-selected samples is derived and the median redshift is found to range from z m = 0.66 at 22 < i + AB < 22.5 to z m = 1.06 at 24.5 < i + AB < 25. At i + AB < 26.0, the multiwavelength COSMOS catalog includes approximately 607,617 objects. The COSMOS-30 photo-z enables the full exploitation of this survey for studies of galaxy and large-scale structure evolution at high redshift.

KW - Galaxies: distances and redshifts

KW - Galaxies: evolution

KW - Galaxies: formation

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U2 - 10.1088/0004-637X/690/2/1236

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EP - 1249

JO - Astrophysical Journal

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