Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-20T00:37:09.865Z Has data issue: false hasContentIssue false

Nearby Blue Compact Dwarf Galaxy NGC 6789

Published online by Cambridge University Press:  25 May 2016

I. Drozdovsky
Affiliation:
Astronomical Institute, St.-Petersburg State University, Petrodvoretz, 198904, Russia
N. Tikhonov
Affiliation:
Special Astrophysical Observatory, N.Arkhyz, Karachai-Circassian Rep., 357147, Russia

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present the results of a detailed BVRI and Hα study of the isolated nearby blue compact dwarf (BCD) galaxy NGC 6789. Judging from the literature the observed galaxy has not yet been resolved into stars up to now. On CCD frames obtained with 6m BTA telescope and 2.5m Nordic telescope the galaxy is well resolved. Its colour-magnitude diagram confirms the two component (core-halo) galaxy morphology, which consists of two stellar populations distinct in structure and colour: an inner high surface-brightness young population within 150 pc from the center of the galaxy, and a relatively low surface-brightness intermediate-age population extending out to at least 600 pc. The distance to the galaxy, estimated from the tip of the red giant branch (TRGB) is 2.1 Mpc which places NGC 6789 close to the Local Group. From the mean colour of the RGB, the mean metal abundance of the halo population is estimated as [Fe/H] ≃ −1 dex.

Type
Part 2: The Database
Copyright
Copyright © Astronomical Society of the Pacific 1999 

References

Burstein, D., Heiles, C. 1984, ApJS, 54, 33 Google Scholar
Cardelli, J.A., Clayton, G.C., Mathis, J.S. 1989, ApJ, 345, 245 Google Scholar
Coleman, C.D., Wu, C.-C., Weedman, D.W. 1980, ApJS, 43, 393 Google Scholar
Da Costa, G.S., Armandroff, T.E. 1990, AJ, 100, 162 Google Scholar
Huchra, J.P., Geller, M.J., Clemens, C.M., Tokarz, S.P., Michel, A. 1995, The CfA Redshift Catalogue NSSDC/ADC Cat. A 7193, Greenbelt, MD: GSFC Google Scholar
Huchtmeier, W.K., Karachentsev, I.D., Karachentseva, V.E. 1997, A&A, 322, 375 Google Scholar
Karachentsev, I.D., Makarov, D.I. 1996, AJ, 111, 794 Google Scholar
Karachentsev, I.D., Makarov, D.I. 1998, A&A, 331, 891 Google Scholar
Karachentseva, V.E., Karachentsev, I.D. 1998, A&AS, 127, 409 Google Scholar
Lee, M.G., Freedman, W.L., Madore, B.F. 1993, ApJ, 417, 553 Google Scholar
Lee, M.G. 1995, JKAS, 28, 169 Google Scholar
Loose, H.H., Thuan, T.X. 1985, in: Star-Forming Dwarf Galaxies and Related Objects , (eds.) Kunth, D., Thuan, T.X. & Van, T.T., Paris: Editions Frontiéres, p. 73 Google Scholar
Sakai, S., Madore, B.F., Freedman, W.L. 1996, ApJ, 461, 713 Google Scholar
Stetson, P.B. 1987, PASP, 99, 191 Google Scholar
Tully, R.B. 1988, Nearby Galaxies Catalogue , Cambridge, CUP Google Scholar
van den Bergh, S. 1994, AJ, 107, 1328 Google Scholar