1. What the Formation of the First Stars Left in its Wake

2. Outline of talk Part 1 History of structure formation in the Universe First stars Visualization Conclusions Part 2 Black hole accretion Conclusions

3. PART 1

4. History of Structure Formation Starts with the Big Bang Uniform and isotropic Universe expands and cools Able to form neutral atoms Matter and radiation are decoupled (epoch of recombination) CMB formed from last scattering Dark ages Matter clumps together; universe becomes more structurally complex First stars form End of Dark ages Beginning of reionization

5. First Stars Important to study? Influenced evolution of the structure of the Universe Synthesized heavy elements Pop III stars Made solely of hydrogen and helium; no heavy metals Massive Thought to be hundreds of solar masses large Because of lack of heavy elements Feedback Effects Ionization Pair-instability supernovae Black holes

7. Visualization Enzo Calculates the numerical data for simulation Uses Adaptive Mesh Refinement Amira Creates the 3D image of the data taken from Enzo Uses photorealistic rendering to create the 3D image of the data IDL Routine (xcamerapath created by Tom Abel) Uses control points to graph the path of the view and distance

8. Conclusions Visualizations used to: Make predictions about how to detect first stars Study and understand the influence of these stars on their surroundings Make conclusions about how structure formation evolved after these stars died Visualizations can also be used to educate the public

9. PART 2

10. Black Hole Accretion If the mass of first stars is less than 140 solar masses or greater than 260 solar masses the star will form black hole 10^9 solar mass seed black holes for quasar formation have been observed at z ~6 Could black holes from first stars be seeds for these quasars?

11. Black Hole Accretion Bondi-Hoyle Accretion Rate Bondi-Hoyle Accretion Rate Assume object at rest in infinite gas cloud Assume object at rest in infinite gas cloud Gas cloud is uniform in density & pressure at infinity, Gas cloud is uniform in density & pressure at infinity, has steady spherical motion has steady spherical motion Accretion given by : Accretion given by : Eddington Accretion Rate Eddington Accretion Rate Largest rate of accretion without reaching Eddington limit Largest rate of accretion without reaching Eddington limit Eddington Limit Eddington Limit Radiative pressure on particles is equal to gravitational force Radiative pressure on particles is equal to gravitational force Availability of gas important Availability of gas important Accretion on object given by : Accretion on object given by :

12. Black Hole Accretion Gives: Where: Solution: Use situation of 10^9 solar mass quasars at z~ 6 Eddington accretion must begin by z ~20 Is there enough matter to begin Eddington accretion?

13. Black Hole Accretion Finding required overdensity for Eddington accretion: Assuming Bondi-Hoyle equal to Eddington we know: Solve for required overdensity : For z ~20, temperature of 10,000 K, mass of 100 solar masses, and radiative efficiency of 0.1: Over-density required: 1.7*10^7 Over-density estimate: 10^4

14. Conclusions Eddington accretion at z ~20 leads to formation of seed black holes for 10^9 quasars at z ~6 Eddington accretion not possible at z ~20 Eddington accretion at z <20 may lead to seed black holes for quasars at z ~6 Initial mass of black hole when Eddington starts is important Come into contact with denser gas clouds More detailed numerical calculations are necessary to make any further conclusions