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:0906.0018)
· References in the article
· Citations to the Article (9) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (4)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Stellar velocity profiles and line strengths out to four effective radii in the early-type galaxies NGC3379 and 821
Authors:
Weijmans, Anne-Marie; Cappellari, Michele; Bacon, Roland; de Zeeuw, P. T.; Emsellem, Eric; Falcón-Barroso, Jesús; Kuntschner, Harald; McDermid, Richard M.; van den Bosch, Remco C. E.; van de Ven, Glenn
Affiliation:
AA(Sterrewacht Leiden, Leiden University, Postbus 9513, 2300 RA Leiden, The Netherlands), AB(Sub-Department of Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH), AC(Centre de Recherche Astrophysique de Lyon, University of Lyon, 9 Avenue Charles André, 69230 Saint Genis Laval, France), AD(European Southern Observatory, Karl-Schwarzschild-Str 2, 85748 Garching, Germany; Sterrewacht Leiden, Leiden University, Postbus 9513, 2300 RA Leiden, The Netherlands), AE(Centre de Recherche Astrophysique de Lyon, University of Lyon, 9 Avenue Charles André, 69230 Saint Genis Laval, France), AF(European Space and Technology Centre, Postbus 299, 2200 AG Noordwijk, The Netherlands), AG(European Southern Observatory, Karl-Schwarzschild-Str 2, 85748 Garching, Germany), AH(Gemini Observatory, Northern Operations Centre, 670 N. A'ohoku Place, Hilo, Hawaii 96720, USA), AI(Sterrewacht Leiden, Leiden University, Postbus 9513, 2300 RA Leiden, The Netherlands; Astronomy Department, University of Texas, Austin, TX 78712, USA), AJ(Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540, USA)
Publication:
Monthly Notices of the Royal Astronomical Society, Volume 398, Issue 2, pp. 561-574. (MNRAS Homepage)
Publication Date:
09/2009
Origin:
MNRAS
MNRAS Keywords:
galaxies: elliptical and lenticular, cD , galaxies: haloes , galaxies: individual: NGC 3379 , galaxies: individual: NGC 821 , galaxies: kinematics and dynamics , dark matter
DOI:
10.1111/j.1365-2966.2009.15134.x
Bibliographic Code:
2009MNRAS.398..561W

Abstract

We use the integral-field spectrograph SAURON to measure the stellar line-of-sight velocity distribution and absorption line strengths out to four effective radii (Re) in the early-type galaxies NGC 3379 and 821. With our newly developed observing technique, we can now probe these faint regions in galaxies that were previously not accessible with traditional long-slit spectroscopy. We make optimal use of the large field-of-view and high throughput of the spectrograph: by adding the signal of all ~1400 lenslets into one spectrum, we obtain sufficient signal-to-noise in a few hours of observing time to reliably measure the absorption line kinematics and line strengths out to large radius.

We find that the line strength gradients previously observed within 1 Re remain constant out to at least 4 Re, which puts constraints on the merger histories of these galaxies. The stellar halo populations are old and metal poor. By constructing orbit-based Schwarzschild dynamical models, we find that dark matter is necessary to explain the observed kinematics in NGC 3379 and 821, with 30-50 per cent of the total matter being dark within 4 Re. The radial anisotropy in our best-fitting halo models is less than in our models without halo, due to differences in orbital structure. The halo also has an effect on the Mgb-Vesc relation: its slope is steeper when a dark matter halo is added to the model.

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