physics: recent developments and observational perspectives

Eric´ Gourgoulhon

Laboratoire Univers et Th´eories (LUTH) CNRS / Observatoire de Paris / Universit´eParis Diderot 92190 Meudon, France [email protected]

http://luth.obspm.fr/~luthier/gourgoulhon/

Semaine de l’Astrophysique Fran¸caise Montpellier, France 5 May 2013

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 1 / 45 Outline

1 The current observational status of black holes What is a black hole ? Known black holes in the Universe

2 The near-future observations of black holes Can we “see” a black hole ? The Telescope instrument at VLTI Athena+ X-ray observatory observations

3 Tests of general relativity The theoretical framework Ongoing work at LUTH / LESIA / CAMK

4 Conclusions and perspectives

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 2 / 45 The current observational status of black holes Outline

1 The current observational status of black holes What is a black hole ? Known black holes in the Universe

2 The near-future observations of black holes Can we “see” a black hole ? The Event Horizon Telescope GRAVITY instrument at VLTI Athena+ X-ray observatory Gravitational wave observations

3 Tests of general relativity The theoretical framework Ongoing work at LUTH / LESIA / CAMK

4 Conclusions and perspectives

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 3 / 45 The current observational status of black holes What is a black hole ? Outline

1 The current observational status of black holes What is a black hole ? Known black holes in the Universe

2 The near-future observations of black holes Can we “see” a black hole ? The Event Horizon Telescope GRAVITY instrument at VLTI Athena+ X-ray observatory Gravitational wave observations

3 Tests of general relativity The theoretical framework Ongoing work at LUTH / LESIA / CAMK

4 Conclusions and perspectives

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 4 / 45 The current observational status of black holes What is a black hole ? What is a black hole ?

... for the layman:

A black hole is a region of spacetime from which nothing, not even light, can escape.

The (immaterial) boundary between the black hole interior and the rest of the Universe is called the event horizon.

[Alain Riazuelo, 2007]

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 5 / 45 The current observational status of black holes What is a black hole ? What is a black hole ?

... for the mathematical physicist:

black hole: B := M − J −(I +) i.e. the region of spacetime where light rays cannot escape to infinity (M , g) = asymptotically flat manifold I + = future null infinity J −(I +) = causal past of I +

event horizon: H := ∂J −(I +) (boundary of J −(I +)) H smooth =⇒ H null hypersurface

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 6 / 45 The current observational status of black holes What is a black hole ? What is a black hole ?

... for the astrophysicist: a very deep gravitational potential well

Release of potential gravitational energy by on a black hole: up to 42% of the mass-energy mc2 of accreted matter !

NB: thermonuclear reactions release less than 1% mc2

Matter falling in a black hole forms an [Lynden-Bell (1969), Shakura & Sunayev (1973)]

[J.-A. Marck (1996)]

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 7 / 45 The current observational status of black holes Known black holes in the Universe Outline

1 The current observational status of black holes What is a black hole ? Known black holes in the Universe

2 The near-future observations of black holes Can we “see” a black hole ? The Event Horizon Telescope GRAVITY instrument at VLTI Athena+ X-ray observatory Gravitational wave observations

3 Tests of general relativity The theoretical framework Ongoing work at LUTH / LESIA / CAMK

4 Conclusions and perspectives

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 8 / 45 Supermassive black holes, in galactic nuclei: 5 10 5 M ∼ 10 – 10 M and R ∼ 3 × 10 km – 200 UA 6 example: Sgr A* : M = 4.3 × 10 M and 6 1 R = 13 × 10 km = 18 R = 0.09 UA = 4 × radius of Mercury’s orbit Intermediate mass black holes, as ultra-luminous X-ray sources (?): 2 4 4 M ∼ 10 – 10 M and R ∼ 300 km – 3 × 10 km

example: ESO 243-49 HLX-1 : M > 500 M and R > 1500 km

The current observational status of black holes Known black holes in the Universe Astrophysical black holes

Three kinds of black holes are known in the Universe: Stellar black holes: remnants: M ∼ 10 – 30 M and R ∼ 30 – 90 km

example: Cyg X-1 : M = 15 M and R = 45 km

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 9 / 45 Intermediate mass black holes, as ultra-luminous X-ray sources (?): 2 4 4 M ∼ 10 – 10 M and R ∼ 300 km – 3 × 10 km

example: ESO 243-49 HLX-1 : M > 500 M and R > 1500 km

The current observational status of black holes Known black holes in the Universe Astrophysical black holes

Three kinds of black holes are known in the Universe: Stellar black holes: supernova remnants: M ∼ 10 – 30 M and R ∼ 30 – 90 km

example: Cyg X-1 : M = 15 M and R = 45 km Supermassive black holes, in galactic nuclei: 5 10 5 M ∼ 10 – 10 M and R ∼ 3 × 10 km – 200 UA 6 example: Sgr A* : M = 4.3 × 10 M and 6 1 R = 13 × 10 km = 18 R = 0.09 UA = 4 × radius of Mercury’s orbit

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 9 / 45 The current observational status of black holes Known black holes in the Universe Astrophysical black holes

Three kinds of black holes are known in the Universe: Stellar black holes: supernova remnants: M ∼ 10 – 30 M and R ∼ 30 – 90 km

example: Cyg X-1 : M = 15 M and R = 45 km Supermassive black holes, in galactic nuclei: 5 10 5 M ∼ 10 – 10 M and R ∼ 3 × 10 km – 200 UA 6 example: Sgr A* : M = 4.3 × 10 M and 6 1 R = 13 × 10 km = 18 R = 0.09 UA = 4 × radius of Mercury’s orbit Intermediate mass black holes, as ultra-luminous X-ray sources (?): 2 4 4 M ∼ 10 – 10 M and R ∼ 300 km – 3 × 10 km

example: ESO 243-49 HLX-1 : M > 500 M and R > 1500 km

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 9 / 45 The current observational status of black holes Known black holes in the Universe Stellar black holes in X-ray binaries

∼ 20 identified stellar black holes in our

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 10 / 45 The current observational status of black holes Known black holes in the Universe Stellar black holes in X-ray binaries

[McClintock et al. (2011)]

Eric´ Gourgoulhon (LUTH) Black hole physics: new perspectives SF2A, Montpellier, 5 May 2013 11 / 45 The current observational status of black holes Known black holes in the Universe Supermassive black holes in active galactic nuclei (AGN)

Jet emitted by the nucleus of the giant elliptic galaxy M87, at the centre of Virgo cluster [HST] 9 MBH = 3 × 10 M Vjet ' 0.99 c

Eric´ Gourgoulhon (LUTH) Black h