Stellar Velocity Profiles and Line-Strengths out to Four Effective Radii in the Early-Type Galaxy NGC 3379

Weijmans, A.; Cappellari, M.; de Zeeuw, P. T.; Emsellem, E.; Falcón-Barroso, J.; Kuntschner, H.; McDermid, R. M.; van den Bosch, R. C. E.; van de Ven, G.
Referencia bibliográfica

Galaxy Evolution: Emerging Insights and Future Challenges ASP Conference Series, Vol. 419, proceedings of a conference held 11-14 November 2008 at the University of Texas, Austin, Texas, USA. Edited by S. Jogee, I. Marinova, L. Hao, and G. A. Blanc. San Francisco: Astronomical Society of the Pacific, 2009., p.179

Fecha de publicación:
12
2009
Número de autores
9
Número de autores del IAC
0
Número de citas
0
Número de citas referidas
0
Descripción
We describe a new technique to measure stellar kinematics and line-strengths at large radii in nearby galaxies. Using the integral-field spectrograph SAURON as a ‘photon-collector’, we obtain spectra out to four effective radii (Re) in the early-type galaxy NGC 3379. By fitting orbit-based models to the extracted stellar velocity profile, we find that ˜40% of the total mass within 5 Re is dark. The measured absorption line-strengths reveal a radial gradient with constant slope out to 4 Re.