Photometry of resolved galaxies. V. NGC 6822
Three-color CCD frames of the local group irregular galaxy NGC 6822 have been reduced to GRI photometry for 3475 stars using RICHFLD point-spread function fitting techniques. The data are compared with earlier work on this galaxy, particularly with Kayser (1966) on a star-by-star basis. While the general agreement between the results of photographic and electronic techniques is good, some differences in detail exist, which are attributed to a small nonlinearity in the photographic results and zero-point offsets of approx.0.1 mag. Color-magnitude diagrams are constructed from the data and compared with both theoretical stellar model tracks and the expected foreground star contamination. A luminosity function for the blue stars (G-R<0) is derived; comparison of this luminosity function with those of 10 other irregular galaxies indicates that NGC 6822 has a typical young star population. The stellar birthrate and initial mass function are estimated for this galaxy. The slope at the bright end of the mass function looks similar to recent results for the Galaxy, the Magellanic Clouds, and the irregular galaxy Sextans A. NGC 6822 appears to be presently forming stars at a slower rate for its mass than Sextans A or the Magellanic Clouds.
- Research Organization:
- Space Telescope Science Institute and Kit Peak National Observatory
- OSTI ID:
- 6103107
- Journal Information:
- Astrophys. J., Suppl. Ser.; (United States), Journal Name: Astrophys. J., Suppl. Ser.; (United States) Vol. 60:2; ISSN APJSA
- Country of Publication:
- United States
- Language:
- English
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Far-infrared properties of NGC 6822
EXTENDED STAR CLUSTERS IN THE REMOTE HALO OF THE INTRIGUING DWARF GALAXY NGC 6822