The Bar Pattern Speed of Dwarf Galaxy NGC 4431

Corsini, E. M.; Aguerri, J. A. L.; Debattista, Victor P.; Pizzella, A.; Barazza, F. D.; Jerjen, H.
Bibliographical reference

The Astrophysical Journal, Volume 659, Issue 2, pp. L121-L124.

Advertised on:
4
2007
Number of authors
6
IAC number of authors
1
Citations
29
Refereed citations
26
Description
We present surface photometry and stellar kinematics of NGC 4431, a barred dwarf galaxy in the Virgo Cluster undergoing a tidal interaction with one of its neighbors, NGC 4436. We measured its bar pattern speed using the Tremaine-Weinberg method and derived the ratio of the corotation radius, DL, to the bar semimajor axis, aB. We found DL/aB=0.6+1.2-0.4 at 99% confidence level. Albeit with large uncertainty, the probability that the bar ends close to its corotation radius (i.e., 1.0<=DL/aB<=1.4) is about twice as likely as that the bar is much shorter than the corotation radius (i.e., DL/aB>1.4). Based on observations collected at the European Southern Observatory, Chile [ESO programs 71.B-0138(A) and 73.B-0091(A)].