The first stars and primordial IMBHs

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1 The first stars and primordial IMBHs Ab initio predictions of black hole merger rates by the time LISA flies? Tom Abel Penn State

2 Initial Conditions

3 Time Evolution z=100 z=24 z= comoving kpc Cosmological Jeans mass ~ 1e4 M 12 comoving kpc on a side, projection of of the simulation volume

4 Under the Assumption of Cold Dark Matter dominated Structure Formation Models there are no Free Parameters in our Calculation No knobs! That s rare...

5 Grids in one intermediate snapshot Level 5, 1924 Level 6, 1423 Level e-7 of box size. Level 8, 123 Level 9, only one has child grids!

6 the first stars Simulation: Tom Abel (PSU), Greg Bryan (Oxford), Mike Norman (UCSD) Viz: Ralf Kähler (AEI, ZIB), Bob Patterson, Stuart Levy, Donna Cox (NCSA), Tom Abel (PSU) The Unfolding Universe Discovery Channel 2002

Why there can be only one Small DM potential drives cold gas to center, cooling flow rather than molecular cloud formation Cooling time longer than dynamical time Inefficient H2 cooling allows

8 Why there can be only one Small DM potential drives cold gas to center, cooling flow rather than molecular cloud formation Cooling time longer than dynamical time Inefficient H2 cooling allows pressure to smooth out density perturbations 3 H H2 does not lead to fragmentation, initial isobaric contraction is weak because of the same cut off temperature, no independent Jeans unstable fragments form. Feedback from first star inhibits others Can be understood analytically: Ripamonti & Abel 2004 MNRAS -> isolated stars with 30 < M < 300

9 ionized fraction temperature density radial velocity

The First Supernovae Yes and no question: Is one supernova enough to blow apart its host micro-galaxy? yes -> Most metals produced end up in the IGM. Where does the next generation of stars form?

10 The First Supernovae Yes and no question: Is one supernova enough to blow apart its host micro-galaxy? yes -> Most metals produced end up in the IGM. Where does the next generation of stars form? Dust formation? How much material will be enriched? Requires radiative transfer, nonequilibrium metal chemistry and cooling, MHD and thermal conduction. > 10^6 solar masses Abel, Bryan & Norman

11 1D implicit adaptive radiation hydrodynamics Ripamonti & Abel

12 Results from 1D radiation-hydro calculation solid: ~ 6000 frequency bins dashed: local approximation ( 100 times faster) Ripamonti & Abel 2004

13 Radiative Transfer in 3D? adaptive ray-tracing using HEALPIX photon conserving at any resolution quad-tree for multiple integrations Abel & Wandelt 2002, MNRAS

14 First Light 2x288^3 SPH particles 1/100 of Milky Way (600 kpc box) Adaptive ray tracing a la Abel & Wandelt 2002, MNRAS ~ 13.5 billion years ago 100 such cubes will eventually make up Milky Way Yoshida, Abel, Hernquist & Sugiyama 2003 ApJ; Yoshida, Abel, Hernquist in prep.

15 Heger & Woosley 2001

16 The First Black Holes? In the preferred range of masses for the first stars the ones with MFS < 140 M ʘ MFS > 260 M ʘ make black holes. Even small kicks ~10km/s -> leave the halo -> less dynamical friction -> smaller LISA signal may be these are not the holes you want to nurture into quasars. Madau & Quatert preprint, Haiman Micic, Abel & Sigurdsson in prep.

17 Dark remnants in the Galaxy? White and Springel 1999 Madau & Rees 2001 Volonteri et al. 2002

18 Black hole formation rate? 10-1 M mini! mini J LW M solar 200 M solar 500 M solar Redshift SNe Rate / dz Cumulative SNe Rate per observed year per square arcminute Wise & Abel in prep.

19 Micic, Abel & Sigurdsson in prep. 2e12M ʘ object at z=1, resolved with 2e6 particles

20 With kicks (Maxwellian with 200 km/s mean) only about 50% of the BHs make it into galaxy. Large number of intergalactic BHs as well as BHs in our halo rather than the center of the Milky Way Without kicks radial distributions more centrally concentrated. Dynamical friction of host halo on background much larger than for a single black holes. Micic, Abel & Sigurdsson in prep.

21 Radial distributions for different kicks N R/Rvir Number of black holes as a function of radius. No kick case in black, kick centered at 75 km/s in red and kick centered at 200 km/s in blue

22 1 0.01![M sun /pc 3 ] e-06 1e R/R vir Density of the host halo at z=1 (black) and its most massive progenitor (red) as a function of radius. Also, density in hosted black holes for no kick (green), kick 75 km/s (blue) and 200 km/s (orange)

23 First Galaxies Assume: White & Rees galaxy formation model: no H2 cooling, full cosmological initial Enclosed Gas Mass [M solar ] n [cm -3 ] Radius [pc] conditions, AMR, z = yrs yrs yrs 6.0 x 10 5 yrs 1.1 x 10 7 yrs z = 7.57 (8.6 x 10 7 yrs) Enclosed Gas Mass [M solar ] v r,gas, c s [km/s] Temperature [K]

24 Collaborators Greg Bryan (Oxford) Emanuele Ripamonti, John Wise, Miroslav Micic (PSU) Mike Norman, Dan Whalen, Brian O Shea (LCA, UCSD) 3D visualizations from a collaboration with Ralf Kähler at the ZIB and AEI

Conclusions Formation of primordial proto-stars is well understood. However, lots of new interesting open questions about the formation of the first stars arose.

$UV escape fraction from the very first objects are unity. The gas leaves halos just because of HII region alone.$

25 Conclusions Formation of primordial proto-stars is well understood. However, lots of new interesting open questions about the formation of the first stars arose. First stars are very massive and form in isolation without planets. Predicting the exact IMV (Initial Mass Value) of the first stars is relying on the development of practical 3d radiative transfer techniques. UV escape fraction from the very first objects are unity. The gas leaves halos just because of HII region alone. All metals of the first supernovae are ejected into the intergalactic medium. Kicks decrease merger rates a factor of a few and would disadvantage first black holes as seeds for quasars

Making Sense of the Universe with Supercomputers

Making Sense of the Universe with Supercomputers Tom Abel Kavli Institute for Particle Astrophysics and Cosmology, Stanford, SLAC Adaptive Mesh Refinement in Cosmology: First Stars Adaptive Ray-Tracing