The BaLROG project - I. Quantifying the influence of bars on the kinematics of nearby galaxies
| Autor: | Seidel, M. K., Falcón-Barroso, J., Martínez-Valpuesta, I., Díaz-García, S., Laurikainen, E., Salo, H., Knapen, J. H. |
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| Rok vydání: | 2015 |
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| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stv969 |
| Popis: | We present the BaLROG (Bars in Low Redshift Optical Galaxies) sample of 16 morphologically 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 {\mu}m 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 kinematics and that stronger bars have enhanced influence on inner kinematic features. We detect that stellar angular momentum "dips" at 0.2$\pm$0.1 bar lengths and half of our sample exhibits an anti-correlation of h3 - stellar velocity (v/{\sigma}) in these central parts. An increased flattening of the stellar {\sigma} gradient with increasing bar strength supports the notion of bar-induced orbit mixing. 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. Comment: 38 pages, 40 figures, accepted for publication in MNRAS, comments are welcome. Some of the figures might lack quality here due to overall size restrictions, please contact us if needed |
| Databáze: | arXiv |
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