Galaxy formation with cosmic strings and massive neutrinos
A detailed calculation of the growth of linear density perturbations induced by a loop of cosmic string in a universe presently dominated by light massive neutrinos is presented. The constant pulling of the cosmic string overcomes free-streaming damping so that cosmological structure develops in a bottom-up fashion different from hot dark matter scenarios without cosmic strings. An accurate semianalytic method for evolving the spherical perturbation around a loop through the collapse stage is developed. Applying this method, it is shown that halos with flat rotation curves form with circular rotation speed of about 50 km/s or greater. The Tremaine and Gunn phase-space constraint limits the compactness of the neutrino halos so that this scenario cannot explain dwarf spheroidals with compact dark halos. The galaxy luminosity function is estimated from the loop size distribution by applying the Faber-Jackson relation to the calculated rotation speeds, and good agreement is found with a Schechter function of slope alpha = 1.4. 59 references.
- Research Organization:
- MIT, Cambridge, MA (USA)
- OSTI ID:
- 7188262
- Journal Information:
- Astrophys. J.; (United States), Vol. 328
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
COSMOLOGY
GALACTIC EVOLUTION
CONSTRAINTS
MAGNETIC FLUX
MAGNETIC MONOPOLES
MASS DISTRIBUTION
NEUTRINO BEAMS
NONLUMINOUS MATTER
PERTURBATION THEORY
PHASE TRANSFORMATIONS
STRING MODELS
BEAMS
COMPOSITE MODELS
DISTRIBUTION
ELEMENTARY PARTICLES
EXTENDED PARTICLE MODEL
LEPTON BEAMS
MATHEMATICAL MODELS
MONOPOLES
PARTICLE BEAMS
PARTICLE MODELS
POSTULATED PARTICLES
QUARK MODEL
SPATIAL DISTRIBUTION
640106* - Astrophysics & Cosmology- Cosmology