Tesis Doctorado
Gas turbulence in the dark matter assembly process: seeds for primordial star formatión.
Autor
Infante-Lira, Leopoldo
Pontificia Universidad Católica de Chile
Institución
Resumen
In this work I pcrformcd a number of cosrnological numcrical simulation of primordial gas with non-cquilibrium chemistry for 21 diffcrcnt spccies inclucling H2. HD and LiH molecular cooling. From cosmological init ial conditions I found that thc intcraction of a~106~1. halo with a ~ 10 7 ~ 1 . halo in the clark matter (D~I) assembly proccss produces a large ammount of super sonic turbulence in thc primorclialgas to z~ 13. Th<'se tmbulence are cnhanccd by the effC'ct of cold gas flowsconverging in t be ~ 107.i\I" halo. The turbulcnre creates gas compressccl regions whcre the H2 ai1cl the HD moleculcs are formed very cffirie11tly ru1d fin ally cool clown the primordial gas devcloping a number of dense clumps v.ith masscs in the rangc from .-v[ewx 102.i\1" to .-vfcwx 103 1\L:- . where primordial stars can he formccl. Underunperturbed primordial conditions. the H2 rnolecule is the main molecular coolantthrough the proccss ancl thc HD and the LiH moleculcs dissipate lcss than 10%of the total dissipated encrgy. For ionizcd pcrturbcd conditions thc HD rnoleculcs domínate tbc gas cooling process in some high dcnsity regions. reaching lower temperatures than in the unperturbed case. under these conditions, the primordial gas sbows more fragmcntation tban in thc unpcrturbed case. Regan.ling t.he eftidcut observed fragmentation (both in unperturbccl and perturbed conditions), I concludethat super sonic turbule11cc develo¡x'd through thc first stages of the Dr..I asscmbly proccss are the seeds for au cfficient star formatiou in primordial cnvironmcnts. In this sense, the turbulent primordial star formation coulcl be very similar to the localstar formation process in super sonic turbulent molecular clouds.