Abstract
Surface BVRI photometry is presented for two spiral galaxies with a complex photometric structure: NGC 834 and NGC 1134. We propose to introduce the combined color indices Q BVI and Q VRI to investigate the photometric structure of the galaxies. These color indices depend only slightly on selective absorption, which allows them to be used to study the photometric structure of “dusty” galaxies. Evolutionary stellar-population models show that Q BVI is most sensitive to the presence of blue stars, while Q VRI depends on local Hα equivalent width. A ring with active star formation manifests itself on the Q BVI map for NGC 834 at a distance of ∼15 from its center, and a spiral structure shows up on the Q VRI map for NGC 1134 in its inner region. The Q BVI –Q VRI diagram can provide information about the current stage of a star's formation in various galactic regions. A comparison of the color indices for the galaxies with their model values allows us to estimate the color excesses and extinction in various galactic regions.
Similar content being viewed by others
References
R. Buta, Astron. J. 111, 591 (1996).
R. Buta and D. Crocker, Astron. J. 105, 1344 (1993).
R. Buta and K. Williams, Astron. J. 109, 543 (1995).
J. Cardelli, G. Clayton, and J. Mathis, Astrophys. J. 345, 245 (1989).
G. Clayton and P. Martin, Astrophys. J. 288, 558 (1985).
D. Elmegreen, Astrophys. J., Suppl. Ser. 43, 37 (1980).
L. Searle, W. L. W. Sargent, and W. G. Bagnuolo, Astrophys. J. 179, 427 (1973).
V. Vansevicius, astro-ph/9906352.
G. Worthey, Astrophys. J., Suppl. Ser.95, 107 (1994).
A. Zasov and A. Moiseev, Pis'ma Astron. Zh. 24, 677 (1998) [Astron. Lett. 24, 584 (1998)].
Author information
Authors and Affiliations
Additional information
__________
Translated from Pis'ma v Astronomicheski\(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l}\) Zhurnal, Vol. 27, No. 4, 2001, pp. 254–265.
Original Russian Text Copyright © 2001 by Bizyaev, Zasov, Ka\(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l}\)sin.
Rights and permissions
About this article
Cite this article
Bizyaev, D.V., Zasov, A.V. & Kaisin, S.S. Combined color indices and photometric structures of the galaxies NGC 834 and NGC 1134. Astron. Lett. 27, 217–227 (2001). https://doi.org/10.1134/1.1358378
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1134/1.1358378