NGC 1672

'NGC 1672' is a barred spiral galaxy located in the constellation Dorado.

Contents

General structure

Nucleus

See also

External links

References

General structure

The center of the galaxy contains a high surface brightness bar, and four filament-like spiral arms extend outward from the ends of this bar. The spiral arms are asymmetric; one of the arms in the northeast part of the disk is significantly brighter than its counterpart on the other side. The spiral arms also contain numerous star formation regions, some of which may be as large as 4′′^[1].

Nucleus

The classification of the nucleus of NGC 1672 is uncertain. Most galaxies may be classified by their spectra as having one of three different types of nuclei:^[2]

★ A nuclear HII region, a region which has a spectrum similar to that of star formation regions in the Milky Way and which therefore is associated with nuclear star formation activity.

★ A Seyfert nucleus, a type of active galactic nucleus (AGN) that may contain a supermassive black hole.

★ A low ionization nuclear emission-line region, a type of nuclear region with spectral line emission from weakly ionized gas that could contain either a star formation region or a supermassive black hole.
NGC 1672, however, is one of several nearby galaxies that does not fit into this classification scheme, as its spectrum appears intermediary between these three classes of objects. It may in fact contain both nuclear star formation regions and an AGN. In some wave bands (such as in ultraviolet light), the star formation regions are the primary source of emission.^[3]

See also

★ NGC 1300 - ''a similar spiral galaxy''

External links

★ 'Hubblesite Newscenter': Pictures and description

References

1. Carnegie Atlas of Galaxies, A. Sandage, J. Bedke, , , Carnegie Institution of Washington, 1994, ISBN 0-87279-667-1
2. AGNs with composite spectra., P. Veron, A. C. Goncalves, M. P. Veron-Cetty, , , Astronomy and Astrophysics, 1997
3. An atlas of ultraviolet spectra of star-forming galaxies, A. L. Kinney, R. C. Bohlin, D. Calzetti, N. Panagia, R. F. G. Wyse, , , Astrophysical Journal Supplement Series, 1993