Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-06-15
2011, ApJ, 738, 58
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
13 pages, 7 figures, 1 table, accepted for publication in ApJ
Scientific paper
10.1088/0004-637X/738/1/58
We present a study on four new star clusters discovered in the halo of the intriguing dwarf irregular galaxy NGC 6822 from a wide field survey covering 3 deg x 3 deg area carried out with MegaCam at Canada-France-Hawaii Telescope (CFHT). The star clusters have extended structures with half-light radii R_h ~ 7.5 -- 14.0 pc, larger than typical Galactic globular clusters and other known globular clusters in NGC 6822. The integrated colors and color magnitude diagrams (CMD) of resolved stars suggest that the new star clusters are 2 -- 10 Gyr old and relatively metal poor with Z=0.0001--0.004 based on the comparison with theoretical models. The projected distance of each star cluster from the galaxy center ranges from 10.7 arcmin (~ 1.5 kpc) to 77 arcmin (~ 11 kpc), far beyond the optical body of the galaxy. Interestingly, the new star clusters are aligned along the elongated old stellar halo of NGC 6822, which is almost perpendicular to the HI gas distribution where young stellar populations exist. We also find that the colors and half-light radii of the new clusters are correlated with the galactocentric distance: clusters farther from the galaxy center are larger and bluer than those closer to the galaxy center. We discuss the stellar structure and evolution of NGC 6822 implied by these new extended star clusters in the halo. We also discuss the current status of observational and theoretical understandings regarding the origin of extended star clusters in NGC 6822 and other galaxies.
Hwang Narae
Kim Sang Chul
Lee Jong Chul
Lee Myung Gyoon
Park Hong Soo
No associations
LandOfFree
Extended Star Clusters in the Remote Halo of the Intriguing Dwarf Galaxy NGC 6822 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 Extended Star Clusters in the Remote Halo of the Intriguing Dwarf Galaxy NGC 6822, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extended Star Clusters in the Remote Halo of the Intriguing Dwarf Galaxy NGC 6822 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-657769