| | |
| | |
Stat |
Members: 3645 Articles: 2'504'928 Articles rated: 2609
25 April 2024 |
|
| | | |
|
Article overview
| |
|
Self-gravitating equilibrium models of dwarf galaxies and the minimum mass for star formation | Eduard I. Vorobyov
; Simone Recchi
; Gerhard Hensler
; | Date: |
7 May 2012 | Abstract: | We construct a series of model galaxies in rotational equilibrium consisting
of gas, stars, and a fixed dark matter (DM) halo and study how these
equilibrium systems depend on the mass and form of the DM halo, gas
temperature, non-thermal and rotation support against gravity, and also on the
redshift of galaxy formation. For every model galaxy we find the minimum gas
mass M_g^min required to achieve a state in which star formation (SF) is
allowed according to contemporary SF criteria. The obtained M_g^min--M_DM
relations are compared against the baryon-to-DM mass relation M_b--M_DM
inferred from the LambdaCDM theory and WMAP4 data. Our aim is to construct
realistic initial models of dwarf galaxies (DGs), which take into account the
gas self-gravity and can be used as a basis to study the dynamical and chemical
evolution of DGs. Rotating equilibria are found by solving numerically the
steady-state momentum equation for the gas component in the combined
gravitational potential of gas, stars, and DM halo using a forward substitution
procedure. We find that for a given M_DM the value of M_g^min depends crucially
on the gas temperature T_g, gas spin parameter alpha, degree of non-thermal
support sigma_eff, and somewhat on the redshift for galaxy formation z_gf.
Depending on the actual values of T_g, alpha, sigma_eff, and z_gf, model
galaxies may have M_g^min that are either greater or smaller than M_b. Galaxies
with M_DM ga 10^9 M_sun are usually characterized by M_g^min la M_b, implying
that SF in such objects is a natural outcome as the required gas mass is
consistent with what is available according to the LambdaCDM theory. On the
other hand, models with M_DM la 10^9 M_sun are often characterized by M_g^min
>> M_b, implying that they need much more gas than available to achieve a state
in which SF is allowed. Abridged. | Source: | arXiv, 1205.1537 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |