Current Paradigm of Direct Collapse BH formation

Transcription

1 Guillermo Haro Workshop, 2015 Current Paradigm of Direct Collapse BH formation Bhaskar Agarwal Yale University (prev: PhD at Max Planck for Extraterrestrial Physics)

2 What is the Problem? SDSS Quasars at z > 6 highest redshift: z = (770 Myr) (Momjian et al. 2013) most massive: z = 6.30 (900 Myr), M = 1.3x10 12 (Wu et al. 2015) First Stars form at z = 20 Latest Planck results push the z lower! How do we grow the Quasars to supermassive scales? time scale is t(z 6 ) - t(z first_star ) ~ 700 Myr* *Take this time with a pinch of salt

3 Solving the problem z t 200 Myr 550 Myr 1 Gyr seed' a BH grow the seed make it a SMBH - For a given BH growth scenario: Bondi-Hoyle, Eddington etc. - sensitive to two parameters M seed t grow

4 The Possible Paths pristine gas in minihalo withstand SF Pop III/II cluster Pop III star: BH: 100 M-sun halo grows: T vir = 10 4 K critical LW radiation NO fragmentation: SMS/QS Merge before 100 M sun go SN BH: 1000 M sun super-edd. BH growth BH: M sun sub-edd. BH growth Quasar BH: 10 9 M sun

5 PopIII stellar BH seeds Heger et al. 2003

6 PopIII stellar BH seeds Volonteri et al. Bromm et al. Yoshida et al. Assuming z f edd = 1 rad. eff = 0.1 M seed = 100 M sun M BH [M sun ] t grow : t 1 {z(20-6)} = 700 Myr t 2 {z(9-6)} = 200 Myr z t age [Myr] 6 t 200 Myr 1 Gyr seed' a BH make it a SMBH

7 Hirano et al PopIII stellar BH seeds: IMF PopIII : IMF Highest mass: 1000 M sun Mstar > 100 M sun desirable seed mass! Doesn t have to be too' common

8 PopIII stellar BH seeds: where? DM Mass ? BH + II* SMBH + II* BH + II* III* PopIII : first sources of light! Minihaloes: M = M sun (DM) Effect on neighbouring haloes: -Moderate LW feedback can kill SF -X-rays feedback -SN 'blow out'

9 PopIII stellar BH seeds: problems highly optimistic scenario! ignores feedback Assuming f edd = 1 rad. eff = 0.1 where is the gas? constant availability of gas form in mini-haloes! merger scenario unclear merger b/w 2 mini-haloes - time-scale - BH present in both M seed = 100 M sun t grow : t 1 {z(20-6)} = 700 Myr t 2 {z(9-6)} = 200 Myr need to be super-edd! all the time!

10 Direct Collapse BH seeds Eisenstein & Loeb Oh & Haiman Bromm & Loeb Koushiappas et al. Bullock & Dekel Lodato & Natarajan z Assuming f edd < 1 rad. eff = 0.1 M seed = M sun M BH [M sun ] t grow : t 1 {z(20-6)} = 700 Myr t 2 {z(9-6)} = 200 Myr t age [Myr] z t 200 Myr 550 Myr 1 Gyr seed' a BH make it a SMBH

11 DCBH seeds: how LW photons: ev Enough LW Radiation H2 + {LW} H2 Delay Pop III Star formation H2 H + H Tvir < 10,000 K

12 DCBH seeds: how LW photons: ev Critical (high) LW Radiation H H H2 Stop Pop III Star formation H + H H Tvir > 10,000 K Pop III n = 10 5 cm 3 T = 200 K 8000 DCBH n = 10 5 cm 3 T = 8000 K M BE ~ 100 M sun M BE ~ 10 5 M sun

13 DCBH seeds: problems Assuming f edd < 1 rad. eff = 0.1 M seed = M sun What is the critical LW flux? HOW does the gas collapse proceed? Feedback from the DCBH once it forms t grow : t 1 {z(20-6)} = 700 Myr t 2 {z(9-6)} = 200 Myr Subsequent merger: with the LW producing galaxy z t 200 Myr 550 Myr 1 Gyr seed' a BH make it a SMBH

14 Do you like movies? Films, cinema. NOT simulation movies My guilty pleasure: BOLLYWOOD! 1. Introduce the audience to your plot 2. Everything is OK, songs/dance 3. Something bad happens! 4. Oh No! 5. There is hope

15 DCBH seeds: where Close to a LW source: Pop II galaxy M = 10 7 M sun (DM) DCBH Continued exposure to LW radiation LW LWcrit Mhot Mhot tdyn tdyn Mcold Mcold tdyn tdyn Metal Free Pop III Polluted Pop II Mhot Outflows Mhot Outflows

16 DCBH seeds: The Hunt SAM Agarwal et al FiBY Dalla Vecchia et al. Agarwal et al Cosmological Volume Yes Yes Minihaloes resolved Yes Yes Halo histories Yes Yes Outflows Yes Yes Pop III + Pop II Yes Yes LW radiation: Spatial + Global Yes Yes Gas No Yes IGM Metal Dispersion No Yes

17 DCBH seeds: The Hunt (SAM) SAM Halo history: Merger Trees Subfind output: LCDM simulation Min halo mass required : at least 10 6 M solar Box Size Cosmology N particles Min. Halo Mass z final 4.86 Mpc WMAP M solar 6

18 DCBH seeds: The Hunt (SAM) DCBH LW LWcrit Mhot Mhot tdyn tdyn Mcold Mcold tdyn tdyn Mhot Mhot Outflows Outflows

19 DCBH seeds: The Hunt (SAM) Reionisation feedback: 13.6 ev : photoionisation / heating of gas in haloes gas needs a larger potential well to re-collapse Vc = 20 km/s (Dijkstra 08) LW Escape Fractions: more photons = more feedback (Ahn et al. 09, Kitayama 04) Stars: Pop II stars (Starburst 99) sfe: 1 % Pop III stars (Schaerer et al.) Range of SAM models Each explores a different parameter set Most vs. Least optimistic scenarios

20 DCBH seeds: The Hunt (SAM) Agarwal et al. 2012

21 DCBH seeds: The Hunt (SAM) PopII J max PopII J bg PopII J crit PopIII J max PopIII J bg PopIII J crit J bg 10 2 J LW z Agarwal et al. 2012

22 DCBH seeds: The Hunt (SAM) 2.0 esc log(dn/dz) [Mpc 3 ] esc esc esc0.5hsfe esc0.5reion z DC sites: Few (<10) at z>6 in a ~100 cmpc 3 box Quasars: few / Gpc 3 at z>6 Discrepancy: 10 7 objects too many! (?) Agarwal et al. 2012

23 DCBH seeds: The Hunt (SAM) z= , , Steeper Two point correlation ξ Halo(DC) / ξ Halo(NoDC) , , z= z= DC sites prefer a more clustered neighbourhood Need to be close to a larger galaxy giving out critical LW flux , , log(d phy ) [pc] Agarwal et al. 2012

24 DCBH seeds: The Hunt (FiBY)

25 DCBH seeds: The Hunt (FiBY) Y [phy. kpc] Y [phy. kpc] X [phy. kpc] Z [phy. kpc] Z [phy. kpc] Y [phy. kpc] X [phy. kpc] Y [phy. kpc] Z [phy. kpc] Log J LW,II Log Z sun Agarwal et al. 2014a X [phy. kpc] Y [phy. kpc] X [phy. kpc] -8.00

26 DCBH seeds: The Hunt (FiBY) J LW DC3 ON08 J LW,II J LW,III J LW,Total 10-1 DC 10 (sites) seems to be more probable than previously thought redshift T vir =10000 K redshift first prog. next prog. DC0 at z= (Agarwal et al. 12 vs. Dijkstra et al. 08) Discrepancy broken if a higher J crit used 7.50 Log(M DM ) [M sun ] (Dijkstra et al 2015) Agarwal et al. 2014a M DM [M sun ] 10 6 T vir =2000 K redshift

27 DCBH seeds: The Evolution DCBH Merger In Situ Pop III Star Pop II Cluster Empty halo Growth of BH ± Stars

28 DCBH seeds: The Evolution Metal Free Pop III Polluted Pop II DCBH Outflows Mhot LW Mhot Mhot LWcrit tdyn Mcold DCBH tdyn tdyn Mcold tdyn Mcold tdyn OBG Phase Mhot flim Mhot Outflows Mcold + Mhot Outflows

29 DCBH seeds: The Evolution O1, z g =6.18 O2, z g =8.93 O3, z g =7.34 O4, z g =6.55 M BH [M O ] f lim = 1.5 f lim = 0.75 f lim = 0.1 f edd = M * [M O ] Agarwal et al. 2013

30 DCBH seeds: Observations Rest wavelength [Å] O1 O2 O3 O4 f lim = 1.5 f lim = 0.75 f lim = m AB Observed wavelength [Å] Agarwal et al. 2014

31 DCBH seeds: Revised Theory? L hv - Rates depend on the shape of incident spectrum of external galaxy - In literature the J crit values have been derived by assuming Pop III source: black body at 10 5 K 1000 Pop II source : black body at 10 4 K (Omukai et al. 01, Shang et al. 10, Wolcott-Green et al. 12, Sugimura et al. 14, Dijkstra et al. 14, Agarwal et al. '15)

32 DCBH seeds: Revised Theory? Rates depend on the shape of the incident spectrum from the external galaxy: relative ratios of 1eV to 12.4 ev photons Agarwal et al. 2014b

33 DCBH seeds: THE J crit Agarwal et al Parameter space reaction rates: kh -, kh2 DC Input the rates directly into the Enzo framework with S.Glover 15 chem. PopIII Find the rate parameter space where you find DC Compare it to rate parameter space from realistic SEDs: Starburst 99

34 DCBH seeds: THE J crit from Starburst99 Agarwal et al ST99: galaxy is placed 5 kpc from the atomic cooling halo de: photo-detachment of H - di: photo-dissociation of H 2

35 DCBH seeds: THE J crit ST99: ISF, Z = IMF: Salpeter [1-100] No unique" value of J crit : depends on the age, SFH of the galaxy Agarwal et al. 2015

36 DCBH seed: Found? Observed by: Sobral et al Claimed as DCBH: Pallotini et al. 2015

37 DCBH seed: found? asterisks: B+C diamonds: A A: BH B+C: stellar Agarwal et al. 2015b in prep

38 DCBH seeds: Recently Latif et al. NO fragmentation Aykutalp et al. X-ray feedback Glover et al. relevant chemistry Scahuer et al. fesc of LW Sugimura et al. Jcrit

39 DCBH: Take Away Message DCBH works maybe too well still << frequent as Pop III seeds Local LW flux essential for z>6 galaxy formation models DCBH form in satellites of LW producing galaxies DCBH prefer clustered environments DCBH can merge with the galaxies later on: OBG Need to account for realistic SEDs : BB not enough QUESTIONS QUESTI All DCBH are not 'future' SMBH

40 Stellar cluster BH seeds Zwart et al. Volonteri et al. Katz et al. Cluster M = M sun Merge within few Myr M BH = M sun Assuming f edd < 1 rad. eff = z M seed = 1000 M sun t grow : t 1 {z(20-6)} = 700 Myr t 2 {z(9-6)} = 200 Myr M BH [M sun ] t age [Myr] z t 200 Myr 550 Myr 1 Gyr seed' a BH make it a SMBH

41 Stellar cluster BH seeds: where? DM Mass ? MBH + II* SMBH + II* MBH + II* II*/III* cluster A proto-galaxy type stellar cluster Metals M = M sun (DM) III* Pre-enrichment : VERY early on

42 Stellar cluster BH seeds: problems Cluster M = M sun Merge within few Myr M BH = M sun Assuming f edd < 1 rad. eff = 0.1 M seed = 1000 M sun t grow : t 1 {z(20-6)} = 700 Myr t 2 {z(9-6)} = 200 Myr formation epoch: Pop II cluster- VERY early on N-body problem mergers: all stars must merge timescale < 3 Myr z t 200 Myr 550 Myr 1 Gyr seed' a BH make it a SMBH