The Effects of X- rays on Star Formation and Black Hole Growth in Young Galaxies

1. The Effects of X-rays on Star FormationandBlack Hole Growth in Young Galaxies Marco Spaans (Kapteyn, Netherlands) AyçinAykutalp (Kapteyn), John Wise (Georgia), Rowin Meijerink (Kapteyn/Leiden)

2. BHs • ManygalaxiescontainBHs : MBH~10-3Mbulge • NeedaccretionontoseedBHsand the formation of Pop III andPopII/I at earlytimes • Even z~6 SMBHs of 109 Mexist • Possibleevolution in Magorrian rel. at high z(Walter ea 04) • BHsproduce UV and X-rayradiation: feedback • SeedBHsformed as remnants of Pop III stars or throughsingularcollapse in primordialatomiccoolinghalos. The latterrequires a strong UV background (103-5 J21) and/or Lyman α trapping(Bromm & Loeb 03, Spaans & Silk06, Shangea 08, Dijsktraea 08, Inayoshi & Omukai12)

3. XDRs • σ ~ E-3 1keV  1022 cm-2 penetration • Secondary Ionizations Dominate • FX =84 L44 r100-2 erg cm-2 s-1 • X-ray flux over 1-100 keV with a power law E-0.9  think of a Seyfert AGN at 100 pc

4. E > 1 keV • Heating: X-rayphoto-ionizationfastelectrons; 10-50% H and H2vibexcitation; UV emission (Ly α, Lyman-Werner) • Cooling: [FeII] 1.26, 1.64; [OI] 63; [CII] 158; [SiII] 35 μm; CO thermalH2 vib; gas-dust • 1 keVphotonpenetrates 1022 cm-2 of NH

5. XDRs • Heating efficiency 10-50% • X-rays penetrate further than UV • High opacity of metal-rich gas  Large energy deposition rate (~FX/nH) • X-rays ionize and drive the ion-molecule chemistry, hence the H2 formation

6. Simulations-1 • Box sizeof 3Mpc/h • 3.6 pcproperresolution • Include X-ray chemistry by porting XDR code (Meijerink&Spaans 05): dust & ion-molecule chemistry, heating, cooling (escape probability for lines); pre-computed tables in nH, NH, FX, and Z/Z(176 species, more than 1000 reactions) • Employ Moray(Wise et. al. 12): UV and X-ray radiation transport (polychromatic spectrum) around the seed BH and every star particle • XDR (metallicity dependent) + Enzo non-equilibrium chemistry (9 species) run in parallel

7. Simulations-2 • Considersingularcollapsescenariofor UV backgrounds of 103 J21and 105 J21, whichfacilitatedestruction of H2andsuppressesfragmentation • Introduceseed BH M=5 x 104 M at z=15 • BH at 10% Eddington(Kim et. al. 11 prescrip.) produces UV (90%) and X-ray (10%) • Star formationrecipesfor Pop III (H2 > 5 x 10-4) and Pop II/I (Z > 10-3.5 Z) from z=30 • SN feedback, metal enrichmentfollowed

8. High opacity effect of metal enriched gas Solar Zero Solar Zero Solar Zero Zero Solar Density-temperature (left) and column density-radius (right) profiles for zero and solar metallicity cases at z=14.95 (top) and z=14.54 (bottom).

9. Low H2 Fraction High Low (103 J21) and high (105J21) UV bg. cases at z=14.95 (left), 14.86 (middle), and 14.78 (right).

10. Pop III stars Low UV bg, at z=14.95!!!

11. Metallicity z=14.78

12. Accretion rate • High UV bg case: 105 J21 • Low UV bg case: 103 J21

13. BH growth Strong UV background prevents growth to a SMBH! X-ray feedback/BH growth self-regulating

14. X-ray Flux

15. X-ray flickering z=14.95 z=14.39 z=13.22 z=12.86 z=12.00 z=12.15

16. HII region High UV bg case, at z=12.86

17. Conclusions • X-rays important & metals boost X-rayopacity heating • Weaker 103 J21 UV background allows Pop III star formationandenrich the medium withmetals • X-ray feedback/BH growth is self-regulating • Singularcollapse scenario does notyieldSMBHs at z=6 for 105 J21 UV background • Interestingthoughforslowlyevolvingdwarfstoday, unlessthere is later time UV weakeningand/or metal enrichment • For low UV bg, 105 M MBH grows at 10-3 M/yr, doubles in mass in Edd. time (usual suspects forSMBHs at z=6)

18. Discussion • 3 Mpc/h box size: Merger rate, maximum halo mass underestimated • No Jets included • Self-shielding approximated locally • No UV background evolution • The simulations are still running!!!