Back to Search
Start Over
The Formation of a Realistic Disk Galaxy in Λ‐dominated Cosmologies
- Source :
- The Astrophysical Journal. 607:688-696
- Publication Year :
- 2004
- Publisher :
- American Astronomical Society, 2004.
-
Abstract
- We simulate the formation of a realistic disk galaxy within the hierarchical scenario of structure formation and study its internal properties to the present epoch. We compare results from a LambdaCDM simulation with a LambdaWDM (2keV) simulation that forms significantly less small scale structure. We show how high mass and force resolution in both the gas and dark matter components play an important role in solving the angular momentum catastrophe claimed from previous simulations of galaxy formation within the hierarchical framework. The stellar material in the disk component has a final specific angular momentum equal to 40% and 90% of that of the dark halo in the LambdaCDM and LambdaWDM models respectively. The LambdaWDM galaxy has a drastically reduced satellite population and a negligible stellar spheroidal component. Encounters with satellites play only a minor role in disturbing the disk. Satellites possess a variety of star formation histories linked to mergers and pericentric passages along their orbit around the primary galaxy. In both cosmologies, the galactic halo retains most of the baryons accreted and builds up a hot gas phase with a substantial X-ray emission. Therefore, while we have been successful in creating a realistic stellar disk in a massive galaxy within the LambdaCDM scenario, energy injection emerges as necessary ingredient to reduce the baryon fraction in galactic halos, independent of the cosmology adopted. (abridged)<br />ApJ in press. Images and movies at http://hpcc.astro.washington.edu/faculty/fabio/galform.html Significantly expanded revised version. (9 pages vs the original 4)
- Subjects :
- Physics
Structure formation
010308 nuclear & particles physics
Star formation
Astrophysics (astro-ph)
Dark matter
FOS: Physical sciences
Astronomy and Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
01 natural sciences
Specific relative angular momentum
Galaxy
Galactic halo
Dark matter halo
Space and Planetary Science
0103 physical sciences
Galaxy formation and evolution
Astrophysics::Earth and Planetary Astrophysics
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
Subjects
Details
- ISSN :
- 15384357 and 0004637X
- Volume :
- 607
- Database :
- OpenAIRE
- Journal :
- The Astrophysical Journal
- Accession number :
- edsair.doi.dedup.....8304206273385ea74e8a631f572cb507