Radiation Sources for
Reionization
Tom Abel
KIPAC/Stanford
Sources
First Stars
Second generation stars
Mini-quasars
Early super-massive black holes
3D RT techniques
Tom Abel
Collaborators
Greg Bryan (Columbia)
Mike Norman, Brian O’Shea & Dan Whalen (UCSD)
Matt Turk & John Wise (KIPAC/Stanford)
Miroslav Micic & Steinn Sigurdsson (PSU)
Naoki Yoshida (Nagoya)
Emanuele Ripamonti (Groningen)
Tom Abel
First Structure Formation
cosmological initial conditions
Follow the rest self-consistently:
Gravity, Hydro, Chemistry and radiative
processes
Leads to stars and black holes -> Feedback ...
Tom Abel
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;
Tom Abel
Yoshida, Abel, Hernquist in prep.
21cm observations at arcsecond scales ...
First Stars
movie
Simulation: Tom Abel (KIPAC/Stanford), Greg Bryan (Columbia), Mike Norman (UCSD)
Viz: Ralf Kähler (AEI, ZIB), Bob Patterson, Stuart Levy, Donna Cox (NCSA), Tom Abel (KIPAC/Stanford)
Tom Abel
© “The Unfolding Universe” Discovery Channel 2002
1D implicit adaptive radiation hydrodynamics Ripamonti & Abel 04, unpublished
Tom Abel
Even in
spherical
symmetry no
predictive theory
Tom Abel
Omukai & Palla 2003, Tan & McKee 03
Accretion unsolved
Stellar masses may be in 30 to 300 solar
masses
Error bar; not a range! Could be peaked at one
value if accretion processes pick out a scale.
upper limit: mass supply
lower limit: Kelvin Helmholtz ~ accretion time
-> Excellent UV emitters
Tom Abel
HII dynamics
Tom Abel
also Kiteyama, Yoshida, Susa & Umemura 2004
Early HII regions
Tom Abel
O’Shea, Abel, Norman & Whalen 05
4 Myr
6.2 Myr
23 Myr
15 Myr
Tom Abel
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Feedback changes ICs
Input on small scales ...
Formation of disks more
common? Binaries? see
Umemura
Caveat: Small numbers
of simulations so far, no
full RT simulations yet
Tom Abel
Mini-quasars
Discussed since 90ies as distinct sources
Luminous accreting black holes with
masses ≤ 1e6 M✺
Involve making BHs and growing them
Postulated also as progenitors of high-z quasars
Harder spectrum, X-ray ionization
Tom Abel
final (remnant) mass
Heger &
Woosley
2001
Tom Abel
Mini-QSOs
T
eReduces clumping
dramatic impact on
chemistry
H2
Kuhlen and Madau, in prep
Tom Abel
Zaroubi & Silk 05
Ricotti, Ostriker 04Haiman and Loeb 98Oh 00 - ....
ρ
Kicks
Mechanisms
Asymmetric expl.
GW emission
Slingshot
Changed
dynamical friction
Tom Abel
Micic, TA, Sigurdsson
Low density
1e-8
Bondi Hoyle accretion
Initially
low density
Would
need to be
in larger
haloes
Tom Abel
1e-11
Early galaxies
All distances are proper
Full Box (92 kpc)
Color scales differ between
slides
Density
Tom Abel
Temperature
John wise & Tom Abel in preparation
Tom Abel
John wise & Tom Abel
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John wise & Tom Abel
Densities
Analytic Disk
averaged profiles
are different
from the
simulations
Tom Abel
Tom Abel
Early galaxies
Neglect PopIII
Assume only HI line cooling
Analytics assume star to form in global disk
In simulations compact objects collapses to <0.1
pc before a global disk forms
SMBH formation
Tom Abel
If you cannot compute it, observe it...
Tom Abel
Sculptor, Fornax and Sextans
Tolstoy et al., ongoing
Followups and additional data with HET: Shetrone et al
3D Transfer Techniques
Given the uncertainties of sources and
internal structures of galaxies, fast
approximate numerical 3D transfer
techniques may be an appropriate tool to
study re-ionization qualitatively
see also talks by Shapiro, Ciardi, Iliev and
Ritzerveld and posters Rijkhorst, Mellema
Tom Abel
2x324^3 SPH simulation, 10/0.7 Mpc box, ~ 10^5 short-lived sources
Approximate Transfer on 200^3 grid, integrating jump condition
Sokasian, Abel & Hernquist, 2000-2003
Tom Abel
Impressive but volume at least a factor 100 too small
see Furlanetto for 21cm
Gnedin & Kravtsov
Implementation of approximate RT: OTVET, of Abel 1999 and Gnedin and Abel 01
See Ricotti et al for applications of OTVET with moving mesh code
Tom Abel
3d transfer in AMR without approximations?
Tom Abel
Abel, Bryan et al in prep.
KIPAC/Stanford
Summary
First stars are massive and isolated ... SNe?
Their HII regions affect next structure formation
First black holes may form in low density
regions and also displaced from DM halo centers
Open questions in hydrodynamics of early
galaxy formation [even neglecting Pop III]
First 3D radiative transfer calculations possible
Observe it ...
Tom Abel