Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:astro-ph/0206062)
· References in the article
· Citations to the Article (8) (Citation History)
· Refereed Citations to the Article
· Also-Read Articles (Reads History)
· HEP/Spires Information
·
· Translate This Page
Title:
Classification and redshift estimation by principal component analysis
Authors:
Cabanac, R. A.; de Lapparent, V.; Hickson, P.
Affiliation:
AA(Institut d'Astrophysique de Paris, CNRS / Univ. Pierre et Marie Curie, 98 bis Bd. Arago, 75014 Paris, France; European Southern Observatory, Vitacura, Alonso de Cordova, 3107, casilla 19001, Santiago, Chile), AB(Institut d'Astrophysique de Paris, CNRS / Univ. Pierre et Marie Curie, 98 bis Bd. Arago, 75014 Paris, France), AC(Dept. of Physics & Astronomy, Univ. British Columbia, 2219 Main Mall, Vancouver, BC V6T1Z4, Canada)
Publication:
Astronomy and Astrophysics, v.389, p.1090-1116 (2002) (A&A Homepage)
Publication Date:
07/2002
Origin:
A&A
A&A Keywords:
galaxies: fundamental parameters, methods: data analysis, Surveys, galaxies: general
DOI:
10.1051/0004-6361:20020665
Bibliographic Code:
2002A&A...389.1090C

Abstract

We show that the first 10 eigencomponents of the Karhunen-Loève expansion or Principal Component Analysis (PCA) provide a robust classification scheme for the identification of stars, galaxies and quasi-stellar objects from multi-band photometry. To quantify the efficiency of the method, realistic simulations are performed which match the planned Large Zenith Telescope survey. This survey is expected to provide spectral energy distributions with a resolution R =~ 40 for ~ 106 galaxies to R <= 23 (z ~ 1), ~ 104 QSOs, and ~ 105 stars. We calculate that for a median signal-to-noise ratio of 6, 98% of stars, 100% of galaxies and 93% of QSOs are correctly classified. These values increase to 100% of stars, 100% of galaxies and 100% of QSOs at a median signal-to-noise ratio of 10. The 10-component PCA also allows measurement of redshifts with an accuracy of sigmaRes. <~ 0.05 for galaxies with z <~ 0 .7, and to sigmaRes. <~ 0.2 for QSOs with z >~ 2, at a median signal-to-noise ratio of 6. At a median signal-to-noise ratio 20, sigmaRes. <~ 0.02 for galaxies with z <~ 1 and for QSOs with z >~ 2.5 (note that for a median S/N ratio of 20, the bluest/reddest objects will have a signal-to-noise ratio of <~ 2 in their reddest/bluest filters). This redshift accuracy is inherent to the R =~ 40 resolution provided by the set of medium-band filters used by the Large Zenith Telescope survey. It provides an accuracy improvement of nearly an order of magnitude over the photometric redshifts obtained from broad-band BVRI photometry.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints