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)
· Full Refereed Scanned Article (GIF)
· arXiv e-print (arXiv:astro-ph/0512200)
· References in the article
· Citations to the Article (47) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (4)
· NED Objects (4)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Kinemetry: a generalization of photometry to the higher moments of the line-of-sight velocity distribution
Authors:
Krajnović, Davor; Cappellari, Michele; de Zeeuw, P. Tim; Copin, Yannick
Affiliation:
AA(Sterrewacht Leiden, Postbus 9513, 2300 RA Leiden, the Netherlands; Denys Wilkinson Building, University of Oxford, Keble Road OX1 3RH), AB(Sterrewacht Leiden, Postbus 9513, 2300 RA Leiden, the Netherlands), AC(Sterrewacht Leiden, Postbus 9513, 2300 RA Leiden, the Netherlands), AD(Institut de Physique Nucléaire de Lyon, 69622 Villeurbanne, France)
Publication:
Monthly Notices of the Royal Astronomical Society, Volume 366, Issue 3, pp. 787-802. (MNRAS Homepage)
Publication Date:
03/2006
Origin:
MNRAS
MNRAS Keywords:
methods: data analysis, techniques: photometric, techniques: spectroscopic, galaxies: kinematics and dynamics, galaxies: photometry
DOI:
10.1111/j.1365-2966.2005.09902.x
Bibliographic Code:
2006MNRAS.366..787K

Abstract

We present a generalization of surface photometry to the higher-order moments of the line-of-sight velocity distribution of galaxies observed with integral-field spectrographs. The generalization follows the approach of surface photometry by determining the best-fitting ellipses along which the profiles of the moments can be extracted and analysed by means of harmonic expansion. The assumption for the odd moments (e.g. mean velocity) is that the profile along an ellipse satisfies a simple cosine law. The assumption for the even moments (e.g. velocity dispersion) is that the profile is constant, as it is used in surface photometry. We test the method on a number of model maps and discuss the meaning of the resulting harmonic terms. We apply the method to the kinematic moments of an axisymmetric model elliptical galaxy and probe the influence of noise on the harmonic terms. We also apply the method to SAURON observations of NGC 2549, NGC 2974, NGC 4459 and NGC 4473 where we detect multiple co- and counter-rotating (NGC 2549 and NGC 4473, respectively) components. We find that velocity profiles extracted along ellipses of early-type galaxies are well represented by the simple cosine law (with 2 per cent accuracy), while possible deviations are carried in the fifth harmonic term which is sensitive to the existence of multiple kinematic components, and has some analogy to the shape parameter of photometry. We compare the properties of the kinematic and photometric ellipses and find that they are often very similar, but a study on a larger sample is necessary. Finally, we offer a characterization of the main velocity structures based only on the kinemetric parameters which can be used to quantify the features in velocity maps.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences


More Article Retrieval Options

HELP for Article Retrieval
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