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Measuring Outer Disk Warps with Optical Spectroscopy

Published online by Cambridge University Press:  01 June 2008

Daniel Christlein
Affiliation:
Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching, Germany email: [email protected]
Joss Bland-Hawthorn
Affiliation:
Institute of Astronomy, School of Physics, University of Sydney, NSW 2006, Australia email: [email protected]
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Abstract

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Warps in the outer gaseous disks of galaxies are a ubiquitous phenomenon, but it is still unclear what generates them. One theory is that warps are generated internally through spontaneous bending instabilities. Other theories suggest that they result from the interaction of the outer disk with accreting extragalactic material. In this case, we expect to find cases where the circular velocity of the warp gas is poorly correlated with the rotational velocity of the galaxy disk at the same radius. Optical spectroscopy presents itself as an interesting alternative to 21-cm observations for testing this prediction, because (i) separating the kinematics of the warp from those of the disk requires a spatial resolution that is higher than what is achieved at 21 cm at low HI column density; (ii) optical spectroscopy also provides important information on star formation rates, gas excitation, and chemical abundances, which provide clues to the origin of the gas in warps. We present here preliminary results of a study of the kinematics of gas in the outer-disk warps of seven edge-on galaxies, using multi-hour VLT/FORS2 spectroscopy.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2009

References

Binney, J. 1992, ARA&A), 30, 51Google Scholar
Binney, J., Jiang, I.-G., & Dutta, S. 1998, MNRAS 297, 1237CrossRefGoogle Scholar
Bland-Hawthorn, J., Freeman, K. C., & Quinn, P. J. 1997, ApJ), 490, 143CrossRefGoogle Scholar
Bosma, A. 1981, AJ, 86, 1791CrossRefGoogle Scholar
Briggs, F. H. 1990, ApJ, 352, 15CrossRefGoogle Scholar
Christlein, D. & Zaritsky, D. 2008, ApJ), 680, 1053CrossRefGoogle Scholar
Cox, A. L., Sparke, L. S., van Moorsel, G., & Shaw, M. 1996, AJ, 111, 1505CrossRefGoogle Scholar
Dekel, A. & Shlosman, I. 1983, IAUS, 100, 187Google Scholar
Dubinski, J. & Kuijken, K. 1995, ApJ, 442, 492CrossRefGoogle Scholar
Hunter, C. & Toomre, A. 1969, ApJ, 155, 747CrossRefGoogle Scholar
Jiang, I.-G. & Binney, J. 1999, MNRAS), 303, 7CrossRefGoogle Scholar
Kuijken, K. 1991, ApJ, 376, 467CrossRefGoogle Scholar
Lynden-Bell, D. 1965, MNRAS, 129, 299CrossRefGoogle Scholar
Nelson, R. W. & Tremaine, S. 1999, MNRAS, 306, 1CrossRefGoogle Scholar
New, K. C. B., Tohline, J. e., Frank, J., & Vaeth, H. M. 1998, ApJ, 503, 632CrossRefGoogle Scholar
Ostriker, E. C. & Binney, J. 1989, MNRAS, 237, 785CrossRefGoogle Scholar
Revaz, Y. & Pfenniger, D. 2004, A&A, 425, 67Google Scholar
Sancisi, R. 1976, A&A, 53, 159Google Scholar
Sanchez-Saavedra, M. L., Battaner, E., & Florido, E. 1990, MNRAS, 246, 458Google Scholar
Sanchez-Saavedra, M. L., Battaner, E., Guijarro, A., López-Correidora, M., & Castro-Rodríguez, N 2003, A&A, 399, 457Google Scholar
Shen, J. & Sellwood, J. A. 2006, MNRAS), 370, 2CrossRefGoogle Scholar
Sparke, L. S. & Casertano, S. 1988, MNRAS, 234, 873CrossRefGoogle Scholar
Toomre, A. 1983, IAUS, 100, 177Google Scholar