The Bar Pattern Speed of Dwarf Galaxy NGC 4431
/ Authors
E. Corsini, J. Aguerri, V. Debattista, A. Pizzella, F. Barazza, H. J. U. D. Padova, Italy., Iac, L. Laguna, Spain.
and 11 more authors
U. Washington, Seattle, Wa, Usa, Brooks Prize Fellow, U. T. A. Austin, Tx, R. S. O. Astronomy, Astrophysics, Weston, Australia.
/ Abstract
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 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).
Journal: The Astrophysical Journal Letters
DOI: 10.1086/518035