Environmental Mechanisms Shaping the Nature of Dwarf Spheroidal Galaxies : The View of Computer Simulations
Author
Source
Issue
Vol. 2010, Issue 2010 (31 Dec. 2010), pp.1-21, 21 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2010-01-26
Country of Publication
Egypt
No. of Pages
21
Main Subjects
Abstract EN
We review numerical works carried out over the last decade on the role of environmental mechanisms in shaping nature of the faintest galaxies known, dwarf spheroidals (dSphs).
The combination of tidally induced morphological transformation, termed tidal stirring, with mass loss due to tidal and ram-pressure stripping aided by heating due to the cosmic ionizing background can turn late-type dwarfs resembling present-day dIrrs into classic dSphs.
The time of infall into the primary halo is shown to be a key parameter.
Dwarfs accreting at z>1, when the cosmic ultraviolet ionizing flux was much higher than today, and was thus able to keep the gas in the dwarfs warm and diffuse, were rapidly stripped of their baryons via ram pressure and tidal forces, producing very dark-matter-dominated objects with truncated star-formation histories, such as the Draco dSph.
The low star-formation efficiency expected in such low-metallicity objects prior to their infall was crucial for keeping their disks gas dominated until stripping took over.
Therefore gas stripping along with inefficient star-formation provides a new feedback mechanism, alternative to photoevaporation or supernovae feedback, playing a crucial role in dwarf galaxy formation and evolution.
We also discuss how the ultra-faint dSphs belong to a different population of lower-mass dwarf satellites that were mostly shaped by reionization rather than by environmental mechanisms (“reionization fossils”).
Finally, we scrutinize the various caveats in the current understanding of environmental effects as well as other recent ideas on the origin of Local Group dSphs.
American Psychological Association (APA)
Mayer, Lucio. 2010. Environmental Mechanisms Shaping the Nature of Dwarf Spheroidal Galaxies : The View of Computer Simulations. Advances in Astronomy،Vol. 2010, no. 2010, pp.1-21.
https://search.emarefa.net/detail/BIM-459737
Modern Language Association (MLA)
Mayer, Lucio. Environmental Mechanisms Shaping the Nature of Dwarf Spheroidal Galaxies : The View of Computer Simulations. Advances in Astronomy No. 2010 (2010), pp.1-21.
https://search.emarefa.net/detail/BIM-459737
American Medical Association (AMA)
Mayer, Lucio. Environmental Mechanisms Shaping the Nature of Dwarf Spheroidal Galaxies : The View of Computer Simulations. Advances in Astronomy. 2010. Vol. 2010, no. 2010, pp.1-21.
https://search.emarefa.net/detail/BIM-459737
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-459737