Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-22T11:53:59.394Z Has data issue: false hasContentIssue false
  • English
  • Français

Effects of reionization on dwarf galaxy formation

Published online by Cambridge University Press:  01 June 2008

Massimo Ricotti
Massimo Ricotti*
Affiliation:
Department of Astronomy, University of Maryland at College Park, College Park, MD 20742 email: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

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.

In this talk I revisit the problem of gas accretion onto minihalos after reionization. I show that primordial minihalos with vcir < 20 km s−1 stop accreting gas after reionization, as is usually assumed, but in virtue of their increasing concentration and the decreasing temperature of the intergalactic medium as redshift decreases, they have a late phase (at redshift z<2) of gas accretion and possibly star formation. As a result we expect that pre-reionization fossils have a more complex star formation history than previously envisioned. A signature of this model is a bimodal star formation history. The dwarf spheroidal galaxy Leo T, that inspired the present work, fits with this scenario. Another prediction of the model is the existence of a population of gas rich minihalos that never formed stars. A subset of compact high-velocity clouds may be identified as such objects but the bulk of them may still be undiscovered.

Keywords

galaxies: dwarfgalaxies: evolutionLocal Groupearly universe
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 4 , Issue S255: Low-Metallicity Star Formation: From the First Stars to Dwarf Galaxies , June 2008 , pp. 142 - 146
Copyright
Copyright © International Astronomical Union 2008

References

Babul, A. & Rees, M. J. 1992, MNRAS, 255, 346CrossRefGoogle Scholar
Bertschinger, E. 1985, ApJS, 58, 39CrossRefGoogle Scholar
Blitz, L., Spergel, D. N., Teuben, P. J., Hartmann, D., & Burton, W. B. 1999, ApJ, 514, 818CrossRefGoogle Scholar
Braun, R. & Burton, W. B. 1999, A&A, 341, 437Google Scholar
Bullock, J. S., Kolatt, T. S., Sigad, Y., Somerville, R. S., Kravtsov, A. V., Klypin, A. A., Primack, J. R., & Dekel, A. 2001, MNRAS, 321, 559CrossRefGoogle Scholar
de Jong, J. T. A., et al. 2008, ApJ, 680, 1112CrossRefGoogle Scholar
Efstathiou, G. 1992, MNRAS, 256, 43PCrossRefGoogle Scholar
Giovanelli, R., et al. 2005, AJ, 130, 2598CrossRefGoogle Scholar
Giovanelli, R., et al. 2007, AJ, 133, 2569CrossRefGoogle Scholar
Maloney, P. R. & Putman, M. E. 2003, ApJ, 589, 270CrossRefGoogle Scholar
Putman, M. E., Bland-Hawthorn, J., Veilleux, S., Gibson, B. K., Freeman, K. C., & Maloney, P. R. 2003, ApJ, 597, 948CrossRefGoogle Scholar
Ricotti, M. 2003, MNRAS, 344, 1237CrossRefGoogle Scholar
Ricotti, M. & Gnedin, N. Y. 2005, ApJ, 629, 259CrossRefGoogle Scholar
Ricotti, M., Gnedin, N. Y., & Shull, J. M. 2002, ApJ, 575, 49CrossRefGoogle Scholar
Ricotti, M., Gnedin, N. Y., & Shull, J. M. 2008, ArXiv e-prints, 802Google Scholar
Ricotti, M., Pontzen, A., & Viel, M. 2007, ApJl, 663, L53CrossRefGoogle Scholar
Ricotti, M. & Wilkinson, M. I. 2004, MNRAS, 353, 867CrossRefGoogle Scholar
Robishaw, T., Simon, J. D., & Blitz, L. 2002, ApJl, 580, L129CrossRefGoogle Scholar
Ryan-Weber, E. V., Begum, A., Oosterloo, T., Pal, S., Irwin, M. J., Belokurov, V., Evans, N. W., & Zucker, D. B. 2008, MNRAS, 384, 535CrossRefGoogle Scholar
Sternberg, A., McKee, C. F., & Wolfire, M. G. 2002, ApJS, 143, 419CrossRefGoogle Scholar
Wechsler, R. H., Bullock, J. S., Primack, J. R., Kravtsov, A. V., & Dekel, A. 2002, ApJ, 568, 52CrossRefGoogle Scholar