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Red Halos of Galaxies – Reservoirs of Baryonic Dark Matter?

Published online by Cambridge University Press:  01 June 2007

E. Zackrisson ,
N. Bergvall ,
C. Flynn ,
G. Östlin ,
G. Micheva  and
B. Caldwell
E. Zackrisson
Affiliation:
Tuorla Observatory, University of Turku, Väisäläntie 20, FI-21500 Piikkiö, Finland Stockholm Observatory, AlbaNova University Center, 106 91 Stockholm, Sweden Department of Astronomy and Space Physics, Box 515, 751 20 Uppsala, Sweden
N. Bergvall
Affiliation:
Department of Astronomy and Space Physics, Box 515, 751 20 Uppsala, Sweden
C. Flynn
Affiliation:
Tuorla Observatory, University of Turku, Väisäläntie 20, FI-21500 Piikkiö, Finland
G. Östlin
Affiliation:
Stockholm Observatory, AlbaNova University Center, 106 91 Stockholm, Sweden
G. Micheva
Affiliation:
Stockholm Observatory, AlbaNova University Center, 106 91 Stockholm, Sweden
B. Caldwell
Affiliation:
Department of Astronomy and Space Physics, Box 515, 751 20 Uppsala, Sweden
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Abstract

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Deep optical/near-IR surface photometry of galaxies outside the Local Group have revealed faint and very red halos around objects as diverse as disk galaxies and starbursting dwarf galaxies. The colours of these structures are too extreme to be reconciled with stellar populations similar to those seen in the stellar halos of the Milky Way or M31, and alternative explanations like dust reddening, high metallicities or nebular emission are also disfavoured. A stellar population obeying an extremely bottom-heavy initial mass function (IMF), is on the other hand consistent with all available data. Because of its high mass-to-light ratio, such a population would effectively behave as baryonic dark matter and could account for some of the baryons still missing in the low-redshift Universe. Here, we give an overview of current red halo detections, alternative explanations for the origin of the red colours and ongoing searches for red halos around types of galaxies for which this phenomenon has not yet been reported. A number of potential tests of the bottom-heavy IMF hypothesis are also discussed.

Keywords

Galaxies: halos – galaxies: stellar content – dark matter – Galaxy: halo – stars: subdwarfs
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 3 , Symposium S244: Dark Galaxies and Lost Baryons , June 2007 , pp. 17 - 25
Copyright
Copyright © International Astronomical Union 2008

References

Abadi, M. G., Navarro, J. F., & Steinmetz, M. 2006, MNRAS, 365, 747CrossRefGoogle Scholar
Alcock, C., Allsman, R. A., Alves, D. R, et al. , 2000, ApJ, 542, 281CrossRefGoogle Scholar
Bergvall, N. & Östlin, G. 2002, A&A, 390, 891Google Scholar
Bergvall, N., Marquart, T., Persson, C., Zackrisson, E. & Östlin, G. 2005, in: Renzini, A.. & Bender, R. (eds.), Multiwavelength Mapping of Galaxy Formation and Evolution, Springer-Verlag, Berlin, p. 355CrossRefGoogle Scholar
Brandner, W. 2005, in: Corbelli, E., Palle, F. & Zinnecker, H. (eds.), The Initial Mass Function 50 years later, Astrophysics and Space Science Library Volume 327, Springer, Dordrecht, p. 101CrossRefGoogle Scholar
Bruzual, G. 2007, to appear in: Vallenari, A., Tantalo, R., Portinari, L., Moretti, A. (eds.), From Stars to Galaxies: Building the Pieces to Build Up the Universe, ASP Conf. Ser., (astro-ph/0702091)Google Scholar
Bullock, J. S. & Johnston, K. V. 2005, ApJ, 635, 931CrossRefGoogle Scholar
Calchi Novati, S., Paulin-Henriksson, S., An, J., et al. 2005, A&A, 443, 911Google Scholar
Caldwell, B. & Bergvall, N 2007, in: Combes, F. & Palous, J. (eds.), Galaxy Evolution Across the Hubble Time, Cambridge University Press, p. 82Google Scholar
Crain, R. A., Eke, V. R., Frenk, C. S., Jenkins, A., McCarthy, I. G., Navarro, J. F., & Pearce, F. R. 2007, MNRAS, 377, 41CrossRefGoogle Scholar
Digby, A. P., Hambly, N. C., Cooke, J. A., Reid, I. N., & Cannon, R. D. 2003, MNRAS, 344, 583CrossRefGoogle Scholar
Fukugita, M. 2004, in: Ryder, S. D., Pisano, D. J., Walker, M. A., & Freeman, K. C. (eds.), International Astronomical Union Symposium no. 220, Astronomical Society of the Pacific., p. 227CrossRefGoogle Scholar
Fukugita, M. & Peebles, P. J. E. 2004, ApJ, 616, 643CrossRefGoogle Scholar
Gould, A., Flynn, C. & Bahcall, J. N. 1998, ApJ, 503, 798CrossRefGoogle Scholar
Gould, A. 2003, ApJ, 583, 765CrossRefGoogle Scholar
Gouliermis, D., Brandner, W. & Henning, T., 2006, ApJ, 641, 838CrossRefGoogle Scholar
James, P. A. & Casali, M. M. 1998, MNRAS, 301, 280CrossRefGoogle Scholar
Klypin, A., Kravtsov, A. V., Valenzuela, O., & Prada, F. 1999, ApJ, 522, 82CrossRefGoogle Scholar
Klypin, A., Zhao, H. & Somerville, R. S. 2002, ApJ, 573, 597CrossRefGoogle Scholar
Lequeux, J., Fort, B., Dantel-Fort, M., Cuillandre, J.-C., & Mellier, Y. 1996, A&A (Letters), 312, L1Google Scholar
Massey, P. 2002, ApJS, 141, 81CrossRefGoogle Scholar
Maraston, C. 2005, MNRAS, 362, 799CrossRefGoogle Scholar
Mathews, W.G. & Brighenti, F. 1999, ApJ, 526, 114CrossRefGoogle Scholar
Michard, R. 2002, A&A, 384, 763Google Scholar
Molinari, E., Buzzoni, A., Chincarini, G., & Pedrana, M. D. 1994, A&A 292, 54Google Scholar
Moore, B., Ghigna, S., Governato, F., Lake, G., Quinn, T., Stadel, J., & Tozzi, P. 1999, ApJ (Letters), 524, L19CrossRefGoogle Scholar
Rudy, R. J., Woodward, C. E., Hodge, T., Fairfield, S. W., & Harker, D. 1997, Nature, 387, 159CrossRefGoogle Scholar
Sackett, P. D., Morrison, H. L., Harding, P., & Boroson, T. A. 1994, Nature, 370, 441CrossRefGoogle Scholar
Scannapieco, E., Kawata, D., Brook, C. B., Schneider, R., Ferrara, A., & Gibson, B.K. 2006, ApJ, 653, 285CrossRefGoogle Scholar
Shang, Z., Brinks, E., Zheng, Z., et al. , 1998, ApJ, 504, 23CrossRefGoogle Scholar
Sommer-Larsen, J. & Dolgov, A. 2001, ApJ, 551, 608CrossRefGoogle Scholar
Spergel, D.N., Bean, R., Doré, O., et al. , 2007, ApJS, 170, 377CrossRefGoogle Scholar
Tisserand, P., Le Guillou, L., Afonso, C, et al. , 2007, A&A, 469, 387Google Scholar
Tully, R. B., Somerville, R. S., Trentham, N., & Verheijen, M. A. W. 2002, ApJ, 569, 573CrossRefGoogle Scholar
Verde, L., Oh, S. P., & Jimenez, R. 2002, MNRAS, 336, 541CrossRefGoogle Scholar
Witt, A. N. & Vijh, U. P. 2004, in: Witt, A. N., Clayton, G. C. & Draine, B. T. (eds.), Astrophysics of Dust, ASP Conference Series, Vol. 309, p. 115Google Scholar
Yost, S. A., Bock, J. J., Kawada, M., Lange, A. E., Matsumoto, T., Uemizu, K., Watabe, T., & Wada, T 2000, ApJ 535, 644CrossRefGoogle Scholar
Zackrisson, E., Bergvall, N., Östlin, G., Micheva, G. & Leksell, M. 2006, ApJ 650, 812CrossRefGoogle Scholar
Zepf, S. E., Liu, M. C., Marleau, F. R., Sackett, P. D., & Graham, J. R. 2000, AJ, 119, 1701CrossRefGoogle Scholar
Zheng, Z., Shang, Z., Su, H., et al. , 1999, AJ, 117, 2757CrossRefGoogle Scholar
Zibetti, S., White, S.D.M. & Brinkmann, J. 2004, MNRAS, 347, 556CrossRefGoogle Scholar
Zibetti, S. & Ferguson, A. M. N. 2004, MNRAS, 352, 6CrossRefGoogle Scholar