Photometric Redshift (PhotoZ)Based on

Intermediate bands & Broad bands

Yan-Bin, Yang Yan-Bin, Yang 杨雁宾杨雁宾Collaborators: Collaborators: .

Xu, Zhou Xu, Zhou 周旭周旭Li-Fang, Xia Li-Fang, Xia 夏丽芳夏丽芳

Zhong-Lue, Wen Zhong-Lue, Wen 文中略文中略(National Astronomical Observatories, CAS)(National Astronomical Observatories, CAS)

Qi-Rong, Yuan Qi-Rong, Yuan 袁启荣袁启荣(Department of Physics, Nanjing Normal University)(Department of Physics, Nanjing Normal University)

2005-11-23, 2005-11-23, 威海 威海 (Wei-Hai)(Wei-Hai)

Outline

IntroductionRedshift, SED, z-SED

Basic methodsPhotometric SystemsPhotoZ by BATC and BATC+SDSSPhotoZ by SDSSStar-SED and galaxy SED

Introduction

V

Redshift (z)

Sepctral Energy Distribution (SED)

Sepctral Energy Distribution (SED)

Problems of Extra-Galactic Research, Proceedings from IAU Symposium no. 15.(1962IAUS...15..390B )

Basic methods

Basic methods - I

Puschell et al. 1982ApJ...257L..57P Bolzonella et al. 2000A&A...363..476B (HYPERZ)Padmanabhan et al. 2005MNRAS.359..237P

Basic methods - II

Koo 1999ASPC..191....3K (and references therein)

Connolly et al. 1995AJ....110.2655CWang et al. 1998AJ....116.2081W

Other methods

Artificial Neural Network (ANN) Vanzella et al. 2004A&A...423..761V Collister & Lahav 2004PASP..116..345CBayesian estimation Benitez 2000ApJ...536..571B

Photometric Systems

BATC

(Beijing-Arizona-Taiwan-Connecticut)

Filter system of BATC

SDSS

Sloan Digital Sky Survey

Filter system of SDSS

PhotoZ by BATC and BATC+SDSS

Basic methods - I

Puschell et al. 1982ApJ...257L..57P Bolzonella et al. 2000A&A...363..476B (HYPERZ)Padmanabhan et al. 2005MNRAS.359..237P

Zhou et al. 2003, PASJ, 55, 891

BATC only

Yuan et al. 2001, AJ, 122, 1718

BATC only

Yuan et al. 2003, ApJS, 149, 53

Yang et al. 2004, ApJ, 600, 141

BATC+SDSS

PhotoZ by SDSS

Previous worksChisq-minimaztion Padmanabhan et al. 2005MNRAS.359..237P

Artificial Neural Network (ANN) Vanzella et al. 2004A&A...423..761V Collister & Lahav 2004PASP..116..345C

PhotoZ by SDSS (Yang et al. 2005)

PhotoZ by SDSS (Yang et al. 2005)

Chisq^2

Color-color-redshift (CCR) relationLinear correction

CCR

CCR

CCR

σ ~ 0.024

CCR

Many Thanks

Many Thanks