Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-07-29
Astron.J.118:1551-1576,1999
Astronomy and Astrophysics
Astrophysics
56 pages, 4 tables and 23 figures, texts in AAS style, to be published in AJ
Scientific paper
10.1086/301041
The WFPC2 of the HST has been used to obtain high-resolution images of NGC 4038/4039 that go roughly 3 magnitudes deeper in V than previous observations made during Cycle 2 (-14 < M_V < -6). To first order the luminosity function (LF) is a power law, with exponent \alpha = -2.12 +/- 0.04. However, after decoupling the cluster and stellar LFs, which overlap in the range -9 < M_V < -6, we find an apparent bend in the young cluster LF at approximately M_V = -10.4. The LF has a power law exponent -2.6 +/- 0.2 in the brightward and -1.7 +/- 0.2 in the faintward. The bend corresponds to a mass ~ 10^5 M_{\odot}, only slightly lower than the characteristic mass of globular clusters in the Milky Way (~2x10^5 M_{\odot}). The star clusters of the Antennae appear slightly resolved, with median effective radii of 4 +/- 1 pc, similar to or perhaps slightly larger than those of globular clusters in our Galaxy. However, the radial extents of some of the very young clusters (ages < 10 Myr) are much larger than those of old globular clusters. A combination of the UBVI colors, \Halpha morphology, and GHRS spectra enables us to age-date the clusters in different regions of The Antennae. We find two groups of young star clusters with ages <~ 20Myr and ~100Myr, as well as an intermediate-age group (~500 Myr) and a handful of old globular clusters from the progenitor galaxies. Age estimates derived from GHRS spectroscopy yield 3 +/- 1 Myr for Knot K (just south of the nucleus of NGC 4038) and 7 +/- 1 Myr for Knot S in the Western Loop, in good agreement with ages derived from the UBVI colors. Effective gas-outflow velocities from Knots S and K are estimated to be about 25-30 km/s. However, the measured widths of the interstellar absorption lines suggest dispersion velocities of ~400 km/s along the lines of sight to Knots S and K.
Fall Michael S.
Leitherer Claus
Miller Bryan W.
Schweizer Francois
Whitmore Bradley C.
No associations
LandOfFree
The Luminosity Function of Young Star Clusters In "The Antennae" Galaxies (NGC 4038/4039) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Luminosity Function of Young Star Clusters In "The Antennae" Galaxies (NGC 4038/4039), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Luminosity Function of Young Star Clusters In "The Antennae" Galaxies (NGC 4038/4039) will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-464088