Astrophys. J., 731, 93 (2011/April-3)
Star clusters in the tidal tails of interacting galaxies: cluster populations across a variety of tail environments.
MULLAN B., KONSTANTOPOULOS I.S., KEPLEY A.A., LEE K.H., CHARLTON J.C., KNIERMAN K., BASTIAN N., CHANDAR R., DURRELL P.R., ELMEGREEN D., ENGLISH J., GALLAGHER S.C., GRONWALL C., HIBBARD J.E., HUNSBERGER S., JOHNSON K.E., MAYBHATE A., PALMA C., TRANCHO G. and VACCA W.D.
Abstract (from CDS):
We have searched for compact stellar structures within 17 tidal tails in 13 different interacting galaxies using F606W- and F814W-band images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope. The sample of tidal tails includes a diverse population of optical properties, merging galaxy mass ratios, H I content, and ages. Combining our tail sample with Knierman et al., we find evidence of star clusters formed in situ with M_ V_< -8.5 and V - I < 2.0 in 10 of 23 tidal tails; we are able to identify cluster candidates to MV= -6.5 in the closest tails. Three tails offer clear examples of "beads on a string" star formation morphology in V - I color maps. Two tails present both tidal dwarf galaxy candidates and cluster candidates. Statistical diagnostics indicate that clusters in tidal tails may be drawn from the same power-law luminosity functions (with logarithmic slopes ~-2 to -2.5) found in quiescent spiral galaxies and interiors of interacting systems. We find that the tail regions with the largest number of observable clusters are relatively young ( ≲ 250 Myr old) and bright (V ≲ 24 mag/arcsec2), probably attributed to the strong bursts of star formation in interacting systems soon after periapse. Otherwise, we find no statistical difference between cluster-rich and cluster-poor tails in terms of many observable characteristics, though this analysis suffers from complex, unresolved gas dynamics and projection effects.
galaxies: interactions - galaxies: photometry - galaxies: star clusters: general
View the references in ADS
To bookmark this query, right click on this link: simbad:2011ApJ...731...93M and select 'bookmark this link' or equivalent in the popup menu