Detalles de publicación

PP 015038

The BaLROG project - I. Quantifying the influence of bars on the kinematics of nearby galaxies

M. K. Seidel (1,2), J. Falcón-Barroso (1,2), I. Martínez-Valpuesta (1,2), S. Díaz-García (3), E. Laurikainen (3,4), H. Salo (3), J. H. Knapen (1,2)
(1) Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain, (2) Departamento de Astrofísica, Universidad de La Laguna, E-38205 La Laguna, Tenerife, Spain, (3) Astronomy and Space Physics, P.O. Box 3000, FI-90014 University of Oulu, Finland, (4) Finnish Center for Astronomy with ESO (FINCA), University of Turku, Finland
We present the BaLROG (Bars in Low Redshift Optical Galaxies) sample of 16 morpholog- ically distinct barred spirals to characterise observationally the influence of bars on nearby galaxies. Each galaxy is a mosaic of several pointings observed with the IFU spectrograph SAURON leading to a tenfold sharper spatial resolution (∼100 pc) compared to ongoing IFU surveys. In this paper we focus on the kinematic properties. We calculate the bar strength Qb from classical torque analysis using 3.6 μm Spitzer (S4G) images, but also develop a new method based solely on the kinematics. A correlation between the two measurements is found and backed up by N-body simulations, verifying the measurement of Qb . We find that bar strengths from ionised gas kinematics are ∼2.5 larger than those measured from stellar kine- matics and that stronger bars have enhanced influence on inner kinematic features. We detect that stellar angular momentum "dips" at 0.2±0.1 bar lengths and half of our sample exhibits an anti-correlation of h3 - stellar velocity (v/σ) in these central parts. An increased flattening of the stellar σ gradient with increasing bar strength supports the notion of bar-induced orbit mix- ing. These measurements set important constraints on the spatial scales, namely an increasing influence in the central regions (0.1-0.5 bar lengths), revealed by kinematic signatures due to bar-driven secular evolution in present day galaxies.

 
Aceptado para publicación en MNRAS | Enviado el 2015-04-29 | Proyecto P/300624