Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-29T16:35:42.608Z Has data issue: false hasContentIssue false

Morphology of the Galactic Bulge from COBE DIRBE Observations

Published online by Cambridge University Press:  25 May 2016

E. Dwek*
Affiliation:
Code 685, NASA/Goddard Space Flight Center, Greenbelt, MD 20771

Extract

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.

The Diffuse Infrared Background Experiment (DIRBE) on-board the Cosmic Background Explorer (COBE) satellite has provided striking new images of the Galactic bulge at effective wavelengths of 1.25, 2.2, 3.5, and 4.9μ (Hauser 1993, plate 3; Arendt et al. 1994; Weiland et al. 1994). The bulge, defined here as the spheroid within the |l| < 20° and |b| < 10° region around the Galactic center, and its stellar content have been subjects of considerable interest since they contain important clues about the dynamical and star-formation history of our Galaxy. The morphology of the Galactic bulge is much harder to ascertain than that of bulges in many external galaxies, because of our location in the Galactic plane amid the obscuration by interstellar dust. In spite of this difficulty, there has recently been an accumulating body of evidence that the stellar distribution in the bulge is bar shaped, i.e. that the bulge is not rotationally symmetric in the plane of the disk (see Blitz 1993 for a review of the subject). The existence of a bar in our Galaxy would have important implications for the dynamics of the Galaxy. A bar would provide a mechanism for sweeping gas from the disk into the Galactic center “feeding” a central black hole (e.g. Shlosman, Frank, & Begelman 1989). It would also provide a mechanism for generating spiral arms, and a basis for estimating the mass of the halo relative to that of the disk (e.g. Combes & Sanders 1981 and references therein).

Type
Chapter 2: Is the Milky Way a Barred Spiral Galaxy?
Copyright
Copyright © Kluwer 1996 

References

Arendt, R. G., et al. 1994, ApJ, 425, L85 Google Scholar
Bahcall, J. N., Schmidt, M., & Soneira, R. 1982, ApJLett, 258, L23 Google Scholar
Binney, J. J., & Gerhard, O. 1993, in Back to the Galaxy, eds. Holt, SS. & Verter, F., (New York: American Institute of Physics), p. 87 Google Scholar
Binney, J. J., Gerhard, O. E., Stark, A. A., Bally, J., & Uchida, K. I. 1991, MNRAS, 252, 210 CrossRefGoogle Scholar
Blanco, V. 1988, AJ, 95, 1400 CrossRefGoogle Scholar
Blitz, L. & Spergel, D. N. 1991, ApJ, 379, 631 CrossRefGoogle Scholar
Blitz, L. 1993, in Back to the Galaxy, eds. Holt, SS. & Verter, F., (New York: American Institute of Physics), p. 98 Google Scholar
Chen, W., Gehrels, N., & Diehl, R. 1994, ApJ, submitted Google Scholar
Combes, F., & Sanders, R. H., 1981, 96, 164 Google Scholar
Combes, F., Debbasch, F., Friedli, D., & Pfenniger, D. 1990, A&A, 233, 82 Google Scholar
de Zeeuw, T. 1992, in The Stellar Populations of Galaxies, ed. Barbuy, B. & Renzini, A. (Dordrecht, Kluwer), 51 Google Scholar
Dwek, E. et al. 1994, accepted for publication in the ApJ Google Scholar
Habing, H. J., Olnon, F. M., Chester, T., Gillett, F., Rowan-Robinson, M., & Neugebauer, G. 1985, A&A, 152, L1 Google Scholar
Hauser, M. G. 1993, in Back to the Galaxy, eds. Holt, S. S. & Verter, F., (New York: American Institute of Physics), p. 201 Google Scholar
Kent, S. M., Dame, T. M. & Fazio, G. 1991, ApJ, 378, 131 CrossRefGoogle Scholar
Liszt, H. S., & Burton, W. B. 1980, ApJ, 236, 779 Google Scholar
Matsumoto, T. et al. 1982, in The Galactic Center, ed. Riegler, G. & Blandford, R. (New York: American Institute of Physics), 48 Google Scholar
Nakada, Y., Deguchi, S., Hashimoto, O., Izumiura, H., Onaka, T., Sekiguchi, K., & Yamamura, JI. 1991, Nature, 353, 140 Google Scholar
Paczynski, B., Stanek, K. Z., Udalski, A., Szymanski, M., Kaluzny, J., & Kubiak, M., Mateo, M., & Krzeminski, W. 1994, ApJ, in press Google Scholar
Raha, N., Sellwood, J. A., James, R. A., & Kahn, F. D. 1991, Nature, 352, 411 Google Scholar
Rowan-Robinson, M. & Chester, T. 1987, ApJ, 313, 413 Google Scholar
Sellwood, J. A. 1993, in Back to the Galaxy, eds. Holt, SS. & Verter, F., (New York: American Institute of Physics), p. 133 Google Scholar
Shlosman, I., Frank, J. & Begelman, M. C. 1989, Nature, 338, 45 Google Scholar
Stanek, K. Z., Mateo, M., Udalski, A., Szymanski, M., Kaluzny, J., & Kubiak, M. 1994, ApJ, 429, L73 CrossRefGoogle Scholar
Statler, T. S. 1987, ApJ, 321, 113 Google Scholar
Vietri, M. 1986, ApJ, 306, 48 Google Scholar
Weiland, J. et al. 1994, ApJ, 425, L81 CrossRefGoogle Scholar
Weinberg, M. D. 1992a, ApJ, 384, 81 Google Scholar
Weinberg, M. D. 1992b, ApJLett, 392, L67 Google Scholar
Whitelock, P. & Catchpole, R. 1992, in The Center, Bulge, and Disk of the Milky Way, ed. Blitz, L. (Dordrecht : Kluwer), p. 103 Google Scholar