The effects of x rays on star formation and black hole growth in young galaxies
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The Effects of X- rays on Star Formation and Black Hole Growth in Young Galaxies. Marco Spaans (Kapteyn, Netherlands). Ayçin Aykutalp (Kapteyn), John Wise (Georgia), Rowin Meijerink (Kapteyn/Leiden ). BHs.

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

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The effects of x rays on star formation and black hole growth in young galaxies

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)


The effects of x rays on star formation and black hole growth in young galaxies

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)


The effects of x rays on star formation and black hole growth in young galaxies

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


E 1 kev

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


The effects of x rays on star formation and black hole growth in young galaxies

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


Simulations 1

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


Simulations 2

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


The effects of x rays on star formation and black hole growth in young galaxies

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).


H 2 fraction

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).


Pop iii stars

Pop III stars

Low UV bg, at z=14.95!!!


Metallicity

Metallicity

z=14.78


Accretion rate

Accretion rate

  • High UV bg case: 105 J21

  • Low UV bg case: 103 J21


Bh growth

BH growth

Strong UV background prevents growth to a SMBH!

X-ray feedback/BH growth self-regulating


X ray flux

X-ray Flux


X ray flickering

X-ray flickering

z=14.95

z=14.39

z=13.22

z=12.86

z=12.00

z=12.15


Hii region

HII region

High UV bg case,

at z=12.86


Conclusions

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)


Discussion

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!!!


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