Pr

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Séminaire multi-échelles SAp Gif-sur-Yvette,
2006 Avril 05
Accrétion et éjection dans les systèmes binaires
dhaute énergie
Marc Ribó CEA Saclay
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OUTLINE

1. X-ray binaries
2. Accretion regimes in neutron stars
3. Microquasars and their multifrequency emission
4. Black hole states and different types of jets
   (correlations)
5. Accretion/ejection and jet formation (propagation
   and ISM)
6. The QPO and the mass scaling (?)
7. Mechanisms of jet formation (?)
8. Conclusions

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X-RAY BINARIES
An X-ray binary is a binary system containing a
compact object (either a neutron star or a
stellar-mass black hole) accreting matter from
the companion star. The accreted matter carries
angular momentum and on its way to the compact
object usually forms an accretion disk,
responsible for the X-ray emission. A total of
280 X-ray binaries are known (Liu et al. 2000,
2001). High Mass X-ray Binaries (HMXBs).
Optical companion with spectral type O or B. Mass
transfer via decretion disk (Be stars) or via
strong wind or Roche-lobe overflow (OB SG) and
SFXT INTEGRAL. There are 131 known HMXBs. Low
Mass X-ray Binaries (LMXBs). Optical companion
with spectral type later than B. Mass transfer
via Roche-lobe overflow. 149 known LMXBs.
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131
149
Radio Emitting X-ray Binaries (REXBs) are X-ray
binaries that display radio emission, interpreted
as synchrotron radiation. Around 43 of the known
280 X-ray binaries (15) are REXBs, including
8 (persistent) HMXBs and 35 (transient) LMXBs.
Abundances Total Galaxy No X-ray
pulsars HMXBs 8/131 ( 6) 8/86 ( 9)
8/37 (22) LMXBs 35/149 (23) 35/147
(24) 34/142 (24)
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ACCRETION REGIMES IN NEUTRONS STARS
Accretion radius (Bondi Hoyle 1944)
ra4GMXvrel2 (impact parameter). Magnetospheric
radius rm B(rm)2/8pr(rm)v(rm)2 (magnetic field
pressureram pressure). Co-rotation radius
rc(GMXPs2/4p2)1/3 (radius with Keplerian
velocity and period Ps). 1. Direct wind
accretion ragtrm and rcgtrm 2. Centrifugal
inhibition of accretion (propeller) rcltrmltra 3.
Magnetic inhibition of accretion (solar
wind) rmgtra 4. Radio pulsar inhibition of
accretion for (ejector) Psltlt1 s. (Stella et al.
1986, ApJ, 308, 669)
rm rc ra
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MICROQUASARS
REXBs displaying relativistic radio
jets. Compact object may be a Neutron Star or a
Black Hole (BH). In BH, the length and time
scales are proportional to the mass, M. The
maximum color temperature of the accretion disk
is Tcol ? 2?107 M?1/4. (Mirabel Rodríguez
1998)
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MICROQUASARS ARTISTS VIEW
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MULTIFREQUENCY EMISSION IN MICROQUASARS
Adapted from Chaty (1998, Ph.D. Thesis)

• Compacts jets
• Radio ? IR
• ? X?
• ? gamma?
• (synchrotron)

• Donor star
• IR ? UV
• (thermal)

• Disc
• corona ?
• X ? IR
• therm non therm

• Large scale ejection
• Radio X
• gamma?
• Interaction with environment

• Dust ?
• IR ? mm
• (thermal)

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BLACK HOLE STATES AND DIFFERENT TYPES OF JETS

• Black holes display different X-ray spectral
  states
• Low/hard state (a.k.a. power-law state).
• High/soft state (a.k.a. thermal-dominant state).

Fender, Corbel, et al. (1999)
Grebenev et al. (1993)
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BLACK HOLE STATES AND DIFFERENT TYPES OF JETS

• Black holes display different X-ray spectral
  states
• Low/hard state (a.k.a. power-law state). Compact
  radio jet.
• High/soft state (a.k.a. thermal-dominant state).
  No radio emission.
• Intermediate and very high states ? transitions.
  Transient radio emission.

Fender (2001)
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COMPACTS JETS radio
Observations image in radio or
spectrum radio flat
Fuchs et al. (2003)
Dhawan et al. (2000)
flat spectrum
GRS 1915105
GRS 1915105
flat or inverted spectrum model conical jet ?
?max ? 1/Rmin shock accelerated e--
emission optically thick synchrotron from
radio ? IR
Falcke et al. (2002)
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COMPACTS JETS X-rays
Corbel Fender (2002)
GX 339-4
? low/ hard state

• synchrotron emission
• radio ? IR ? X ?
• Optically thin Synchrotron in X-rays ?

Inverted spectrum
Corbel et al. (2003)
GX 339-4

• radio X-ray correlation Frad ? FX0.7
• over more than 3 decades in flux
• ? Universal law ?
• ex V404 Cyg, XTE J1118480
• ? ? lt 10
• compact jet model can account for
• the slope by only varying the jet power

• other possibility Inverse Compton of the soft
  photons by e-- from the jet basis

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Gallo et al. (2003) found a correlation between
radio and X-ray flux for Black Holes in the
low/hard state. If the X-rays not beamed, then
the Lorentz factors of the compact radio jets
should be smaller than 2 to account for the small
scattering of the correlation.
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VLBA images of GRS 1915105 reveal an asymmetric
compact jet.
24 March
2.0 cm 3.6 cm
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VLBA images of GRS 1915105 reveal an asymmetric
compact jet.
24 March
2.0 cm 3.6 cm
2 April
2.0 cm 3.6 cm
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VLBA images of GRS 1915105 reveal an asymmetric
compact jet.
24 March
2.0 cm 3.6 cm
2 April
2.0 cm 3.6 cm
19 April
2.0 cm 3.6 cm
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VLBA images of GRS 1915105 reveal an asymmetric
compact jet. We infer
b0.2-0.4, Glt1.1, compatible with the above ideas
(Ribó et al. 2004).
24 March
2.0 cm 3.6 cm
2 April
2.0 cm 3.6 cm
19 April
2.0 cm 3.6 cm
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The X-ray nova SWIFT J1753.5-0127, observed
during a low/hard state X-ray outburst in August
2005, does not fit in the correlation (Cadolle
Bel et al. 2006).
10 kpc
5 kpc
1 kpc
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ISOLATED (SUPERLUMINAL) EJECTIONS
? same Lorentz factor as in Quasars ? 5-10

VLBI at 22 GHz 1,3 cm
VLA at 3,5 cm
arcsec. scale
milliarcsec. scale
Mirabel Rodríguez (1994)

• Move on the plane of the sky 103 times faster
• Jets are two-sided (allow to solve equations ?
  max. distance)
• Advantage of AGN at lt100 Mpc collimation at
  30-100 Rsh (M87, Junor et al. 1999)

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VARIABILITY accretion / ejection coupling
Chaty (1998), Mirabel et al. (1998)

• Cycles of 30 minutes in GRS 1915105
• Ejections after an X-ray dip
• Disappearance / refilling of the internal part of
  the disc ?
• Transient ejections during state changes

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SUMMARY ABOUT JETS
state transition
low/hard state
quiescence off states
high/soft state
Fender, Belloni Gallo (2004)
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XTE J1550-564 LARGE SCALE X-RAY JETS !
Chandra images 0.3 - 8 keV
Also the source H 1743-322
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Jet-blown ring around Cygnus X-1, at the tail of
the HII nebula Sh2-101 (Gallo et al. 2005). In
analogy with extragalactic jet sources, the ring
could be the result of a strong shock that
develops at the location where the pressure
exerted by the collimated jet, shown in the
inset, is balanced by the ISM. Assumi
ng minimum energy conditions, this yields an
expected lobe synchrotron surface brightness more
than 150 times brighter than the observed ring
either the system is far from equipartition, or
the most of the energy is stored in non-radiating
particles, presumably baryons.
8'
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LS 5039 from radio and GeV emission from EGRET
(Paredes et al. 2000) to VHE gamma rays, TeV,
with HESS (Aharonian et al. 2005).
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LS 5039 from radio and GeV emission from EGRET
(Paredes et al. 2000) to VHE gamma rays, TeV,
with HESS (Aharonian et al. 2005).
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LS 5039 from radio and GeV emission from EGRET
(Paredes et al. 2000) to VHE gamma rays, TeV,
with HESS (Aharonian et al. 2005).
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LS 5039 from radio and GeV emission from EGRET
(Paredes et al. 2000) to VHE gamma rays, TeV,
with HESS (Aharonian et al. 2005).
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LS 5039 from radio and GeV emission from EGRET
(Paredes et al. 2000) to VHE gamma rays, TeV,
with HESS (Aharonian et al. 2005).
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LS 5039 from radio and GeV emission from EGRET
(Paredes et al. 2000) to VHE gamma rays, TeV,
with HESS (Aharonian et al. 2005).
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LS 5039 from radio and GeV emission from EGRET
(Paredes et al. 2000) to VHE gamma rays, TeV,
with HESS (Aharonian et al. 2005).
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THE QPO AND THE MASS SCALING
Quasi Periodic Oscillations (QPOs) of X-ray count
rates in X-ray binaries can be of low (Hz) or
high frequency (kHz). The kHz QPOs sometimes come
in pairs with a 32 ratio. The frequency of the
upper kHz QPO seems to be correlated with 1/M for
3 microquasars (McClintock Remillard
2003). In the context of non-linear
resonances between the two epicyclic frequencies
in the inner regions of the accretion disc
(Kluzniak Abramowicz 2000), there is a good
agreement with the 17 min period of Sgr A
(Genzel et al. 2003) or the 1912 min pair
(Aschenbach et al. 2004). This could allow us to
unveil the mass of ultraluminous X-ray sources
(Abramowicz et al. 2004).
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MECHANISMS OF JET FORMATION
Energy and angular momentum can be extracted from
a rotating black hole by a purely electromagnetic
mechanism (Blandford Znajek 1977). A
ngular momentum is removed magnetically from an
accretion disk by field lines that leave the disk
surface, and is eventually carried off in a jet
moving perpendicular to the disk (Blandford
Payne 1982).
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Magnetohydrodynamic simulations show a
well-defined jet that extracts energy from a
rotating black hole. If plasma near the black
hole is threaded by large-scale magnetic flux, it
will rotate with respect to asymptotic infinity,
creating large magnetic stresses. These stresses
are released as a relativistic jet at the expense
of black hole rotational energy. The physics of
the jet initiation in the simulations is
described by the theory of black hole
gravitohydromagnetics. (Semenov et al. 2004).
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CONCLUSIONS

• X-ray binaries show relativistic jets from AU to
  pc scales.
• They allow us to study the coupling between
  accretion and ejection processes on timescales
  much shorter than in quasars.
• Extended jets show evidence for external shocks
  capable of accelerating electrons up to energies
  of several TeV. They are also able to blow huge
  structures and give us clues on their composition
  and energy balance.
• The microquasar LS 5039 shows a SED extending up
  to the TeV range. Particle acceleration,
  gamma-gamma absorption, etc. New laboratories.
• Timing of accretion disk QPOs can reveal the
  central mass of the black hole and maybe solve
  the ULX enigma.
• There is no consensus on the mechanisms of jet
  formation. Kerr BHs can be effective, but there
  are neutron stars showing relativistic jets as
  well.