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Star formation in galaxy mergers: ISM turbulence, dense gas excess, and scaling relations for disks and starbusts

Published online by Cambridge University Press:  12 August 2011

Frédéric Bournaud ,
Leila C. Powell ,
Damien Chapon  and
Romain Teyssier
Frédéric Bournaud
Affiliation:
CEA, IRFU, SAp – CEA Saclay, F-91191 Gif-sur-Yvette, France. email: frederic.bournaud@cea.fr
Leila C. Powell
Affiliation:
CEA, IRFU, SAp – CEA Saclay, F-91191 Gif-sur-Yvette, France. email: frederic.bournaud@cea.fr
Damien Chapon
Affiliation:
CEA, IRFU, SAp – CEA Saclay, F-91191 Gif-sur-Yvette, France. email: frederic.bournaud@cea.fr
Romain Teyssier
Affiliation:
CEA, IRFU, SAp – CEA Saclay, F-91191 Gif-sur-Yvette, France. email: frederic.bournaud@cea.fr
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Abstract

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Galaxy interactions and mergers play a significant, but still debated and poorly understood role in the star formation history of galaxies. Numerical and theoretical models cannot yet explain the main properties of merger-induced starbursts, including their intensity and their spatial extent. Usually, the mechanism invoked in merger-induced starbursts is a global inflow of gas towards the central kpc, resulting in a nuclear starburst. We show here, using high-resolution AMR simulations and comparing to observations of the gas component in mergers, that the triggering of starbursts also results from increased ISM turbulence and velocity dispersions in interacting systems. This forms cold gas that are denser and more massive than in quiescent disk galaxies. The fraction of dense cold gas largely increases, modifying the global density distribution of these systems, and efficient star formation results. Because the starbursting activity is not just from a global compacting of the gas to higher average surface densities, but also from higher turbulence and fragmentation into massive and dense clouds, merging systems can enter a different regime of star formation compared to quiescent disk galaxies. This is in quantitative agreement with recent observations suggesting that disk galaxies and starbursting systems are not the low-activity end and high-activity end of a single regime, but actually follow different scaling relations for their star formation.

Keywords

galaxies: formationgalaxies: mergersgalaxies: star formation
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 6 , Symposium S271: Astrophysical Dynamics: From Stars to Galaxies , June 2010 , pp. 160 - 169
Copyright
Copyright © International Astronomical Union 2011

References

Agertz, O., et al. 2009a, MNRAS, 392, 294Google Scholar
Barnes, J. E. & Hernquist, L. E. 1991, ApJL, 370, L65CrossRefGoogle Scholar
Barnes, J. E. 2004, MNRAS, 350, 798CrossRefGoogle Scholar
Bournaud, F., Duc, P.-A., & Emsellem, E. 2008, MNRAS, 389, L8CrossRefGoogle Scholar
Bournaud, F. 2010, ASP Conference Series, 423, 177, arXiv:0909.1812v2Google Scholar
Bournaud, F., Elmegreen, B. G., Teyssier, R., Block, D. L., & Puerari, I. 2010, MNRAS 409, 1088CrossRefGoogle Scholar
Bournaud, F. et al. , ApJ submitted, arXiv:1006.4782Google Scholar
Burkert, A. 2006, Comptes Rendus Physique, 7, 433CrossRefGoogle Scholar
Chien, L.-H. & Barnes, J. E. 2010, MNRAS, 407, 43Google Scholar
Cox, T. J., Jonsson, P., Somerville, R. S., Primack, J. R., & Dekel, A. 2008, MNRAS, 384, 386CrossRefGoogle Scholar
Crocker, A. F., Bureau, M., Young, L. M., & Combes, F. 2010, submitted to MNRASGoogle Scholar
Cullen, H., Alexander, P., & Clemens, M. 2006, MNRAS, 366, 49Google Scholar
Di Matteo, P., Combes, F., Melchior, A.-L., & Semelin, B. 2007, A&A, 468, 61Google Scholar
Di Matteo, P., Bournaud, F., Martig, M., Combes, F., Melchior, A.-L., & Semelin, B. 2008, A&A, 492, 31Google Scholar
Daddi, E., et al. 2010a, ApJ, 713, 686Google Scholar
Daddi, E., et al. 2010b, ApJL, 714, L118Google Scholar
Duc, P.-A., Brinks, E., Wink, J. E., & Mirabel, I. F. 1997, A&A, 326, 537Google Scholar
Elmegreen, B. G., Kaufman, M., & Thomasson, M. 1993, ApJ, 412, 90CrossRefGoogle Scholar
Elmegreen, D. M., Kaufman, M., Brinks, E., Elmegreen, B. G., & Sundin, M. 1995, ApJ, 453, 100CrossRefGoogle Scholar
Elmegreen, B. G. 2002, ApJ, 577, 206CrossRefGoogle Scholar
Elmegreen, D. M., Elmegreen, B. G., Ravindranath, S., & Coe, D. A. 2007, ApJ, 658, 763CrossRefGoogle Scholar
Le Floc'h, E., et al. 2005, ApJ, 632, 169CrossRefGoogle Scholar
Fabello, S., et al. 2010, MNRAS in press, arXiv:1009.4309Google Scholar
Förster Schreiber, N. M., et al. 2009, ApJ, 706, 1364Google Scholar
Genzel, R., et al. 2010, MNRAS, 407, 2091Google Scholar
Green, A. W., et al. 2010, Nature, 467, 684CrossRefGoogle Scholar
Hammer, F., Flores, H., Elbaz, D., Zheng, X. Z., Liang, Y. C., & Cesarsky, C. 2005, A&A, 430, 115Google Scholar
Irwin, J. A. 1994, ApJ, 429, 618CrossRefGoogle Scholar
Jogee, S., et al. 2009, ApJ, 697, 1971Google Scholar
Juneau, S., Narayanan, D. T., Moustakas, J., Shirley, Y. L., Bussmann, R. S., Kennicutt, R. C. & Vanden Bout, P. A. 2009, ApJ, 707, 1217CrossRefGoogle Scholar
Kim, J.-h., Wise, J. H., & Abel, T. 2009, ApJL, 694, L123CrossRefGoogle Scholar
Krumholz, M. R. & Thompson, T. A. 2007, ApJ, 669, 289Google Scholar
Lombardi, M., Lada, C. J., & Alves, J. 2010, A&A, 512, A67Google Scholar
Martig, M. & Bournaud, F. 2008, MNRAS, 385, L38Google Scholar
Martig, M., Bournaud, F., Teyssier, R., & Dekel, A. 2009, ApJ, 707, 250Google Scholar
Mihos, J. C. & Hernquist, L. 1996, ApJ, 464, 641Google Scholar
Narayanan, D., et al. 2010, MNRAS, 401, 1613Google Scholar
Robaina, A. R., et al. 2009, ApJ, 704, 324CrossRefGoogle Scholar
Saitoh, T. R. et al. 2009, PASJ, 61, 481Google Scholar
Sanders, D. B., et al. 1988, ApJ, 325, 74Google Scholar
Smith, B. J., et al. 2008, AJ, 135, 2406Google Scholar
Struck, C. 1997, ApJS, 113, 269Google Scholar
Tacconi, L. J., et al. 2008, ApJ, 680, 246Google Scholar
Tasker, E. J. & Tan, J. C. 2009, ApJ, 700, 358Google Scholar
Teyssier, R., Chapon, D., & Bournaud, F. 2010, ApJL 720, 149Google Scholar
Toomre, A. & Toomre, J. 1972, ApJ, 178, 623Google Scholar
Truelove, J. K., et al. 1997, ApJL, 489, L179CrossRefGoogle Scholar
Wada, K., Meurer, G., & Norman, C. A. 2002, ApJ, 577, 197Google Scholar
Wang, Z., et al. 2004, ApJS, 154, 193Google Scholar