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Triggering Comet-Like Activity of Main Belt Comets

Published online by Cambridge University Press:  01 March 2016

N. Haghighipour
Affiliation:
Institute for Astronomy, University of Hawaii-Manoa, HI, USA email: [email protected]
T. I. Maindl
Affiliation:
Department of Astrophysics, University of Vienna, Austria email: [email protected]
C. Schäfer
Affiliation:
Institut für Astronomie und Astrophysik, Eberhard Karls Universität Tübingen, Germany
R. Speith
Affiliation:
Physikalisches Institut, Eberhard Karls Universität Tübingen, Germany
R. Dvorak
Affiliation:
Department of Astrophysics, University of Vienna, Austria email: [email protected]
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Abstract

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Main Belt Comets (MBCs) have attracted a great deal of interest since their identification as a new class of bodies by Hsieh and Jewitt in 2006. Much of this interest is due to the implication that MBC activity is driven by the sublimation of volatile material (presumed to be water-ice) presenting these bodies as probable candidates for the delivery of a significant fraction of Earth's water. Results of the studies of the dynamics of MBCs suggest that these objects might have formed in-situ as the remnants of the break-up of large icy asteroids. Simulations also show that collisions among MBCs and small objects could have played an important role in triggering the cometary activity of these bodies. Such collisions might have exposed sub-surface water-ice which sublimated and created thin atmospheres and tails around MBCs. In order to drive the effort of understanding the nature of the activation of MBCs, we have investigated these collision processes by simulating the impacts in detail using a smooth particle hydrodynamics (SPH) approach that includes material strength and fracture models. We have carried out simulations for a range of impact velocities and angles, allowing m-sized impactors to erode enough of an MBC's surface to expose volatiles and trigger its activation. Impact velocities were varied between 0.5 km/s and 5.3 km/s, and the projectile radius was chosen to be 1 m. As expected, we observe significantly different crater depths depending on the impact energy, impact angle, and MBC's material strength. Results show that for all values of impact velocity and angle, crater depths are only a few meters, implying that if the activity of MBCs is due to the sublimation of water-ice, ice has to exist in no deeper than a few meters from the surface. We present details of our simulations and discuss the implications of their results.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2016 

References

Agnor, C. & Asphaug, E. 2004, ApJ, 613, L157CrossRefGoogle Scholar
Benz., W., Asphaug, E. 1999, Icarus, 142, 5Google Scholar
Bottke, W. F., Nolan, M. C., Greenberg, R., & Kovoord, R. A. 1994, Icarus, 107, 255Google Scholar
Grady, D. E. & Kipp, M. E. 1993, in: Asay, J. R. & Shahinpoor, M., High Pressure Shock Compression of Solids (Springer-Verlag, New York), Chapter 5, 265Google Scholar
Haghighipour, N. 2009, Meteorit. Planet. Sci., 44, 1863Google Scholar
Haghighipour, N. 2010, in: Fernández, J. A., Lazzaro, D., Prialnik, D., & Schulz, R. (eds) Icy Bodies of the Solar System, Proceedings of the IAU Symposium 263, 207Google Scholar
Haghighipour, N. & Winter, O. C. 2016, Celest. Mech. Dynamic. Astron., in pressGoogle Scholar
Haghighipour, N., Maindl, T. I., Schäfer, C., Speith, R., & Dvorak, R. 2016, Activation of Main Belt Comets, ApJ, submittedGoogle Scholar
Hsieh, H. H., Jewitt, D. C., & Fernández, Y. R. 2004, AJ, 127, 2997Google Scholar
Hsieh, H. H. & Jewitt, D. C. 2006, Science, 312, 561Google Scholar
Izidoro, A., de SouzaTorres, K. Torres, K., Winter, O. C., & Haghighipour, N. 2013, ApJ, 767, 54Google Scholar
Izidoro, A., Haghighipour, N., Winter, O. C.., & Tsuchida, M. 2014, ApJ, 782, 31Google Scholar
Jewitt, D., Hsieh, H., & Agarwal, J. 2015, in: Michel, P., DeMeo, F., & Bottke, W. (eds), ASTEROIDS-IV, in press (arXiv:1502.02361)Google Scholar
Maindl, T. I., Schäfer, C., Speith, R., Süli, Á., Forgács-Dajka, E., & Dvorak, R. 2013, Astro. Nachrich., 334, 996CrossRefGoogle Scholar
Maindl, T. I., Dvorak, R., Schäfer, C., & Speith, R. 2014, in: Knežević, Z. & Lemaître, A. (eds), Complex Planetary Systems, Proceedings of the IAU Symposium 310, 138CrossRefGoogle Scholar
Maindl, T. I., Dvorak, R., Lammer, H., Güdel, M., Schäfer, C., Speith, R., Odert, P., Erkaev, N. V., Kislyakova, K. G., & Pilat-Lohinger, E. 2015, A&A, 574, A22Google Scholar
Melosh, J. H. 1996, Impact Cratering: A Geological Process (Oxford University Press)Google Scholar
Michel, P., O'Brien, D. P., Abe, S., & Hirata, N. 2009 Icarus, 200, 503Google Scholar
Nakamura, A. M., Patrick, M., & Masato, S. 2007, JGR, 112, id.E02001Google Scholar
Nakamura, A. M., Hiraoka, K., Yamashita, Y., & Machii, N. 2009, Planet. Space. Sci., 57, 111CrossRefGoogle Scholar
Prialnik, D. & Rosenberg, E. D. 2009, MNRAS, 399, L97Google Scholar
Raymond, S. N., Quinn, T., & Lunine, J. I. 2004, Icarus, 168, 1Google Scholar
Raymond, S. N., O'Brien, D. P., Morbidelli, A., & Kaib, N. A. 2009, Icarus, 203, 644Google Scholar
Schäfer, C., Speith, R., & Kley, W. 2007, A&A, 325, 84Google Scholar
Schorghofer, N. 2008 ApJ, 682, 697Google Scholar