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2- deg2的COSMOS 30带测光红移

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. … 展开作者

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 Fevre, S. Lilly, D. Looper, C. Maier, V. Mainieri, Y. Mellier, M. Mignoli, T. Murayama, R. Pello, Y. Peng, E. Perez-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

摘要:

我们提出了精确的光度红移在2-deg 2宇宙领域。红移是用30个宽、中、窄波段计算的,涵盖了紫外(GALEX)、可见近红外(斯巴鲁、CFHT、UKIRT和NOAO)和中红外(斯皮策/IRAC)。使用chi 2模板拟合方法(Le Phare),并用来自VLT-VIMOS和Dikk-DEIMOS的大光谱样品进行校准。我们开发并实现了一种新的方法,占的贡献,从发射线(OII,Hbeta,Halpha和Ly)的光谱能量分布(SED)。发射谱线的处理将photo-z精度提高了2.5倍。将导出的photo-z与4148个光谱红移(即Δ z = zs-zp)进行比较,表明在i<22.5时色散为sigma_{Delta z/(1+zs)} =0.007,比COSMOS、CFHTLS和COMBO-17巡天中早期photo-z精确2-6倍。在较暗的幅度i<24和z<1.25时,精度为sigma_{Delta z/(1+zs)} =0.012。深度近红外和IRAC覆盖使photo-z能够扩展到z~2,尽管准确度较低(i~24时sigma_{Delta z/(1+zs)} =0.06)。导出了大星等选择样品的红移分布,发现红移的中值范围从z=0.66(22<i<22.5)到z=1.06(24.5<i<25)。在i<26.0时,多波长COSMOS星表包括大约607,617个天体。COSMOS-30 photo-z使这一巡天能充分利用于高红移星系和大尺度结构演化的研究。

英文摘要:

We present accurate photometric redshifts in the 2-deg2 COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrow bands covering the UV (GALEX), Visible-NIR (Subaru, CFHT, UKIRT and NOAO) and mid-IR (Spitzer/IRAC). A chi2 template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from VLT-VIMOS and Keck-DEIMOS. We develop and implement a new method which accounts for the contributions from emission lines (OII, Hbeta, Halpha and Ly) 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. Delta z = zs - zp) indicates a dispersion of sigma_{Delta z/(1+zs)}=0.007 at i<22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHTLS and COMBO-17 survey fields. At fainter magnitudes i<24 and z<1.25, the accuracy is sigma_{Delta z/(1+zs)}=0.012. The deep NIR and IRAC coverage enables the photo-z to be extended to z~2 albeit with a lower accuracy (sigma_{Delta z/(1+zs)}=0.06 at i~24). The redshift distribution of large magnitude-selected samples is derived and the median redshift is found to range from z=0.66 at 22<i<22.5 to z=1.06 at 24.5<i<25. At i<26.0, the multi-wavelength COSMOS catalog includes approximately 607,617 objects. The COSMOS-30 photo-z enable the full exploitation of this survey for studies of galaxy and large scale structure evolution at high redshift.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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