Primordial Black Holes in Cosmology Lecture 4: Accretion physics - PowerPoint PPT Presentation

Primordial Black Holes in Cosmology Lecture 4: Accretion physics Massimo Ricotti (University of Maryland, USA) Institute of Cosmos Sciences, University of Barcelona 23/10/2017

Astrophysical Constraints • Microlensing • Macho, EROS, etc • UCMHs: lensing, astrometry, DM annihilation • Dynamical constraints • Power spectrum • Dynamical heating (halo binaries and dwarfs) • Gravitational waves from binary PBHs • Capture • Primordial binaries • Effects on CMB and reionization Institute of Cosmos Sciences, University of Barcelona

Collaborators: Jerry Ostriker (Princeton), Katie Mack (Princeton) Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.2/37

Physics of PBHs accretion: Outline Gas accretion onto PBHs produce X-rays and affect the ionization history of the IGM 1. Growth of “clothing” dark matter halo (100-1000 times more massive than PBH) 2. Gas viscosity: Compton Drag and Hubble flow 3. Proper motion: gas and dark matter are not perfectly coupled (Silk damping) 4. Angular momentum of accreted gas and dark matter 5. Feedback processes (global and local radiative feedbacks) Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.12/37

1. Clothing Dark Matter Halo 1. PBHs seed accumulation of dark halo ( f pbh < 1 ) 2. The gas accretion rate onto the PBH is increased! Ref: Mack, Ostriker and Ricotti (2007) growth of order unity during radiation era � 1+ z � − 1 M h = 3 M pbh 1000 Self-similar secondary infall solution ( e.g. , Bertschinger 1985) Truncated power-law density profile with α = − 2 . 25 Truncation at r h = r ta / 3 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.13/37

2. Bondi type accretion Spherical accretion ( √ ) Steady-state ( M < 2 × 10 4 M � , √ ) Viscosity (Compton drag) dv x e σ T U cmb dt = − 4 v = − β v m p c 3 Hubble expansion ( M > 2 × 10 4 M � , √ ) Clothing dark halo (power-law density profile, √ ) Ref: Ricotti (2007) Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.14/37

Spherical accretion rate point mass potential (dashed curves) dark halo poten- tial (solid curves) Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.15/37

3. Relative motion of PBHs and gas M g ∝ M 2 ˙ v 3 eff s ) 1 / 2 where v eff = ( v 2 rel + c 2 1. Linear regime: Silk damping ( i = baryons, dark matter) � ∞ � V i � 2 = Ω 1 . 2 m H 2 P i ( k ) w 2 s ( k, a ) w 2 l ( k, r 0 ) dk, 2 π 2 0 � ∞ � σ i � 2 = Ω 1 . 2 m H 2 P i ( k ) w 2 s ( k, a )[1 − w 2 l ( k, r 0 )] dk. 2 π 2 0 2. Non-linear regime: capture by mini-halos Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.16/37

Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.17/37

Angular momentum of accreted material Dark matter: Quasi-spherical accretion Ang. momentum sufficiently large to avoid direct accretion of DM into PBH Gas: Spherical accretion for M < 500 M � Compton drag reduces further ang. momentum (Loeb 93; Umemura et al 93) Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.18/37

4. Accretion rate neglecting feedback curves from bottom to top refer to masses of PBHs from 0 . 1 M � to 10 5 M � (factor of 10 spacing). Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.19/37

4. Accretion rate neglecting feedback curves from bottom to top refer to masses of PBHs from 0 . 1 M � to 10 5 M � (factor of 10 spacing). Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.19/37

Accretion Luminosity Define dimensionless luminosity l = L/L Ed and accretion m = ˙ M/ ˙ rate ˙ M Ed , then: m , where � is the radiative efficiency l = � ˙ We assume: m 2 if ˙ m < 1 (spherical accretion) l = 0 . 01 ˙ m ) < f duty if ˙ m > 1 (thin disk) l = f duty (0 . 1 ˙ Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.20/37

5. Feedback processes Local feedbacks (typically negligible) Size of H II region with respect to Bondi radius: In most cases r H II /r B < 1 If r H II /r B > 1 l l � l � t = = 1 + ( r H II /r B ) 1 / 3 = f duty l 1 + t off /t on Temperature of H II region: T H II ∼ T cmb Global feedback (X-ray heating): Iterative semi-analytic code (Ricotti & Ostriker 04) Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.21/37

Cosmic ionization, thermal, and chem- ical history Simulations: M pbh = 100 , f pbh = 10 − 4 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.22/37

Cosmic ionization, thermal, and chem- ical history Simulations: M pbh = 1000 , f pbh = 10 − 7 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.22/37

Cosmic ionization, thermal, and chem- ical history Simulations: M pbh = 1000 , f pbh = 10 − 6 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.22/37

Effects of PBHs on CMB anisotropies Affects recombination Complementary and uncorrelated to reionization effects Affect small angu- lar scales: l>10 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.28/37

Modified recombination history � � � − 1 � 1 + z x e ( z ) = x e,rec ( z ) + min , 0 . 1 x e 0 , 1000 Created using CosmoloGUI 1 0.8 Probability 0.6 0.4 0.2 0 2 4 6 8 10 x e 10 4 RECFAST: Seager, Sasselov & Scott 99 ; COSMOMC: Lewis & Bridle 02 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.29/37

Created using CosmoloGUI 0.4 0.35 0.3 0.25 ! 0.2 0.15 0.1 2 4 6 8 10 x e 10 4 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.30/37

Created using CosmoloGUI 18 16 14 z re 12 10 8 2 4 6 8 10 x e 10 4 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.30/37

Created using CosmoloGUI 1.1 1.08 1.06 1.04 n s 1.02 1 0.98 0.96 0.94 2 4 6 8 10 x e 10 4 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.30/37

Created using CosmoloGUI 34 32 30 log(10 10 A s ) 28 26 24 22 20 2 4 6 8 10 x e 10 4 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.30/37

New constraints on f PBH and β Results (2008) Ricotti, Ostriker, Mack 2008 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.31/37

New constraints on f PBH and β Results (2008) Ricotti, Ostriker, Mack 2008 Institute of Cosmos Sciences, University of Barcelona Physics Coll. Virginia Tech, 02-08-2008 – p.31/37

Results (2016) � wide binaries micro-lensing ����� Planck (strong feedback) Planck (no feedback) u l t r a - f a i n t ��� ( � ��� ) d w ����� a r f s ����� R O M �� - � �� - � �� � ��� � �� ��� ���� � ��� / � ⊙ Ali-Haimoud and Kamionkowski 2016 (arXiv:1612.05644) Institute of Cosmos Sciences, University of Barcelona

Results (2016) Horowitz 2016, (arXiv:1612.07264) Institute of Cosmos Sciences, University of Barcelona

Poulin et al. 2017 10 0 10 � 1 10 � 2 10 � 3 f PBH 10 � 4 10 � 5 10 � 6 Accretion constraints Other constraints Other constraints Spherical accretion [57] Micro-lensing [38] Micro-lensing [38] 10 � 7 Disk accretion with v e ff = c s, 1 Radio [47] Radio [47] p c s, 1 h v 2 L i 1 / 2 Disk accretion with v e ff = Dynamical heating of star cluster [40] Dynamical heating of star cluster [40] 10 � 8 10 � 1 10 0 10 1 10 2 10 3 M PBH /M �

1) Effect of Supersonic Motions �� L i 1 / 2 h v 2 see: Tseliakhovich and Hirata 2010, Dvorkin, Blum, and Kamionkowski 2014 �������� ( �� / � ) v e ff �� v B � � ��� ��� ���� �� � �� � Ali-Haimoud and Kamionkowski 2016 � Ricotti, Ostriker, Mack 2008 �� � �� � � ��� �� � �� �� � �� �� �� �� ��� ���� �� � �� � �

2) Radiative Efficiency �� - � 1 M � 1 0 2 �� - � M ϵ � � � �� - � 10 4 M � no feedback �� - � strong feedback �� ��� ��� ���� ���� �� � � Ali-Haimoud and Kamionkowski 2016 Institute of Cosmos Sciences, University of Barcelona