A strong bound on the dark matter fraction in primordial black holes - PowerPoint PPT Presentation

A strong bound on the dark matter fraction in primordial black holes from astronomical data. Daniele Gaggero

DM candidates: 90 orders of magnitude in mass 10 19 GeV 10 57 GeV Axion-like particles 10 -22 eV 1 eV 1 GeV 1 TeV (10 -5 g) (10 33 g) “ Fuzzy” Dark Primordial black holes Weakly interacting massive Matter (PBHs) particles (WIMPS) λ dB ~ 1 kpc ~ size of a e.g. lightest neutralino state in dSph Galaxy [Zeld’ovich and Novikov 1966, MSSM Hawking 1971] [Hui, Ostriker, Tremaine, Witten many constraints from 2016] lensing, wide binaries, Galactic disk stability became less popular after MACHO and EROS results [ Alcock 2001] now reconsidered in the DM community, as we will see Flic-en-Flac 03/05/2017 Padova 22/06/2017 Berlin 30/08/2018

The PBH - DM connection • Primordial black holes can collapse in the early Universe out of small-scale large density fluctuations formed during the inflation era, as soon as the over-densities re- enter the horizon [Y. B. Zel’dovich and I. D. Novikov, Soviet Astronomy 10, 602 (1967); S. Hawking, MNRAS 152, 75 (1971); Carr and Hawking, MNRAS 168 (1974); recent review: Sasaki et al. arXiv:1801.05235] • Do massive PBHs constitute a significant fraction of the Dark Matter in the Universe? [Chapline, Nature, vol. 253, Jan. 24, 1975] • Are the massive PBHs observed by LIGO and Virgo of primordial origin? Is the merger rate inferred by LIGO and Virgo compatible with this hypothesis? [Bird et al. arXiv: 1603.00464; Sasaki et al. arXiv:1603.08338; Ali-Haïmoud et al. arXiv:1709.06576; Kavanagh et al. arXiv: 1805.09034] Power spectrum 1/2 log P ( k ) − 1 10 GBLW ('96) CGB ('15) − 5 10 Λ CDM CMB LSS reion Garcia-Bellido log k 1702.08275 Pisa 12/01/2017 Berlin 30/08/2018 UCI meeting SLAP meeting CAPS meeting Flic-en-Flac 03/05/2017 LPTHE 14/02/2017 Padova 22/02/2017

The PBH - DM connection • Primordial black holes can collapse in the early Universe out of small-scale large density fluctuations formed during the inflation era, as soon as the over- densities re-enter the horizon [Y. B. Zel’dovich and I. D. Novikov, Soviet Astronomy 10, 602 (1967); S. Hawking, Mon. Not. R. Astron. Soc. 152, 75 (1971); Carr and Hawking, MNRAS 168 (1974); recent review: Sasaki et al. arXiv:1801.05235] • Do massive PBHs constitute a significant fraction of the Dark Matter in the Universe? [Chapline, Nature, vol. 253, Jan. 24, 1975] • Can PBHs be the seeds of IMBHs and SMBHs? Power spectrum 1/2 log P ( k ) Black Hole Mass Distribution log n ( M ) − 1 10 GBLW ('96) SBH PBH IMBH SMBH CGB ('15) − 5 10 Garcia-Bellido Λ CDM 1702.08275 CMB LSS reion log M Garcia-Bellido log k 10 3 M Θ 10 9 M Θ 1 M Θ 50 M Θ 1702.08275 Berlin 30/08/2018 LPTHE 14/02/2017 Padova 22/02/2017 Flic-en-Flac 03/05/2017 CAPS meeting SLAP meeting UCI meeting Pisa 12/01/2017

Current constraints Pisa 12/01/2017 LPTHE 14/02/2017 Padova 22/02/2017 Flic-en-Flac 03/05/2017 CAPS meeting SLAP meeting UCI meeting Berlin 30/08/2018

The region under the spotlight � wide binaries micro-lensing ����� P Planck (no feedback) ultra-faint dwarfs l a n c k ��� ( � ��� ) ( s ����� t r o n g f e e d ����� b R O a M c k ) �� - � �� - � �� � ��� � �� ��� ���� � ��� / � ⊙ Ali-Haimoud and Kamionkowski, 1612.05644 Pisa 12/01/2017 UCI meeting Berlin 30/08/2018 SLAP meeting CAPS meeting Flic-en-Flac 03/05/2017 Padova 22/02/2017 LPTHE 14/02/2017

Our idea: Look at radio and X-ray data • If ~30M ⊙ PBHs are the DM: ~10 11 objects in the Milky Way, ~10 8 in the Galactic bulge. • Given the large amount of gas in the inner Galaxy, how easy is it to hide such a population of PBHs? • Given conservative estimates of the accretion rate and radiative efficiency, is this population of PBHs compatible with current radio (VLA) and X-ray (NuStar, Chandra) observations? Our approach: A MC simulation • We populated the Galaxy with PBHs, and computed the predicted X-ray and radio luminosity • We produced simulated maps of predicted bright X-ray and radio sources and compared to data The crucial ingredient: Physics of gas accretion onto PBHs • What is a conservative estimate of the accretion rate? • We chose a conservative, small fraction λ ~ 0.02 of the Bondi-Hoyle-Lyttleton rate, compatible with recent data-driven analyses � � 3 / 2 ˙ M = 4 πλ ( GM BH ) 2 ρ v 2 BH + c 2 � s [see e.g. isolated neutron star population estimates and studies of active galactic nuclei accretion R. Perna, et al., ApJ 598, 545 (2003), astro-ph/ 0308081; S. Pellegrini, ApJ 624, 155 (2005), astro-ph/050203] UCI meeting Pisa 12/01/2017 LPTHE 14/02/2017 Padova 22/02/2017 Flic-en-Flac 03/05/2017 CAPS meeting SLAP meeting Berlin 30/08/2018

Results X-rays: A strong bound in the 10 - 100 Msun [10-40 keV band; ROI: -0.9° < l < 0.3°; -0.1° < b < 0.4°] range! The constraining power mainly • Prediction: more than 3000 bright X-ray sources comes from BHs in the low-velocity tail of • Observed sources in the ROI by Chandra: ~400 the BH distribution (v < 10 km/s) accreting (40% are cataclysmic variables) gas in the Central Molecular Zone Radio: [1 GHz; ROI: -0.5° < l < 0.5°; |b| < 0.4°] See B. Kavanagh’s poster for a • Prediction 40±6 bright radio sources in the ROI complimentary approach and a stronger • Observed radio sources in the ROI: 170 bound based on the merger rate of PBH • N umber of candidate black holes in the ROI: 0 binaries formed in the early universe! assuming BHs obey the Fundamental Plane relation 10 0 10 0 DM fraction f PBH = Ω PBH / Ω DM PBH DM fraction f DM 10 � 1 10 � 1 EROS+MACHO 10 � 2 Eridanus II Accretion - radio Accretion - X-ray Radio 5 σ X-ray 5 σ CMB - PLANCK Radio 3 σ X-ray 3 σ CMB - FIRAS Radio 2 σ X-ray 2 σ 10 � 3 10 � 2 10 � 2 10 � 1 10 0 10 1 10 2 10 3 10 4 10 5 20 40 60 80 100 PBH mass [ M � ] M PBH [ M � ] Pisa 12/01/2017 Berlin 30/08/2018 UCI meeting SLAP meeting CAPS meeting Flic-en-Flac 03/05/2017 Padova 22/02/2017 LPTHE 14/02/2017

The role of the mass function • Primordial black holes can originate from a variety of mechanisms and can exhibit broad mass functions of different shapes. 1 femtolensing EROS 0.1 WMAP3 MACHO DM 0.01 FIRAS PBH PBH 0.001 NS capture 10 4 EGB Deng&Vilenkin 1710.02865 10 5 Clesse & 10 18 10 13 10 8 0.001 100 10 7 Garcia-Bellido 1501.07565 M PBH M Flic-en-Flac 03/05/2017 Pisa 12/01/2017 Berlin 30/08/2018 UCI meeting SLAP meeting CAPS meeting LPTHE 14/02/2017 Padova 22/02/2017

The role of the mass function • It is crucial to re-evaluate the constraints depending of the shape of the expected mass function! • A remapping method has been proposed in Bellomo+ 1709.07467 EROS-2 MACHO Ultra-Faint Dwarf Galaxies CMB (Spherical Accretion) ˆ f CMB PBH 10 0 10 0 ˆ ˆ f CMB f EROS2 PBH PBH ˆ f MACHO PBH ˆ f UFDG PBH ˆ f UFDG ˆ f MACHO PBH PBH ˆ f EROS2 PBH f PBH 10 � 1 10 � 1 dM d Φ EMD Z f MMD PBH g ( M eq , { p j } ) = f EMD g ( M, { p j } ) , PBH dM 10 � 2 10 � 2 • The method is based on the calculation M EROS2 M MACHO eq eq of the equivalent mass 10 0 M CMB eq 10 � 1 • The equivalent mass is, by definition, 10 � 2 d Φ /dM M UFDG 10 � 2 eq the effective mass associated with a M CMB monochromatic PBHs population such 10 � 3 M MACHO eq M UFDG eq eq 10 � 3 that the observable effects produced 10 � 4 M EROS2 eq by the latter are equivalent to the ones 10 � 5 produced by the EMD 10 � 6 10 � 4 10 0 10 1 10 2 10 3 10 0 10 1 10 2 10 3 M [ M � ] M [ M � ] Pisa 12/01/2017 Berlin 30/08/2018 UCI meeting SLAP meeting CAPS meeting Flic-en-Flac 03/05/2017 Padova 22/02/2017 LPTHE 14/02/2017

The role of the mass function • We analyzed the impact of different mass distribution functions on our results via dedicated numerical simulations, and compared to the remapping method proposed in Bellomo+ 1709.07467 Results for log-normal EMDs: 10 0 10 0 Preliminary! Preliminary! Radio X-ray PBH DM fraction f DM PBH DM fraction f DM 10 � 1 10 � 1 LN σ = 0 . 75 LN σ = 0 . 75 Delta Delta LN σ = 0 . 25 LN σ = 0 . 90 LN σ = 0 . 25 LN σ = 0 . 90 LN σ = 0 . 50 LN σ = 1 . 00 LN σ = 0 . 50 LN σ = 1 . 00 10 � 2 10 � 2 20 40 60 80 100 20 40 60 80 100 PBH mass [ M � ] PBH mass [ M � ] J. Manshanden, D. Gaggero, G. Bertone et al., in preparation J. Manshanden, “Black Hole Dark Matter”, M.Sc. thesis, University of Amsterdam SLAP meeting UCI meeting Berlin 30/08/2018 Pisa 12/01/2017 CAPS meeting Flic-en-Flac 03/05/2017 Padova 22/02/2017 LPTHE 14/02/2017

The role of the mass function Results for power-law EMDs: 100 1 . 0 • For each mass γ = � 0 . 5 γ = � 0 . 5 0 . 8 80 distribution, represented 0 . 6 by a point in the ( Mmax, 0 . 4 60 M min > M max M min > M max M min [ M � ] Mmin )-space, the color f DM 0 . 2 40 represents the DM fraction f DM that is excluded with a 0 . 1 X-ray 5 σ significance Radio 20 0 . 05 20 40 60 80 100 20 40 60 80 100 M max [ M � ] M max [ M � ] 100 1 . 0 γ = 0 γ = 0 0 . 8 80 0 . 6 0 . 4 60 M min > M max M min > M max M min [ M � ] f DM 0 . 2 40 0 . 1 Radio X-ray 20 0 . 05 20 40 60 80 100 20 40 60 80 100 M max [ M � ] M max [ M � ] J. Manshanden, D. Gaggero, G. Bertone et al., in preparation Pisa 12/01/2017 Berlin 30/08/2018 UCI meeting SLAP meeting CAPS meeting Flic-en-Flac 03/05/2017 Padova 22/02/2017 LPTHE 14/02/2017