X-ray binary jets: a.k.a. microquasars

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X-ray binary jets a.k.a. microquasars
Rob Fender (Southampton)
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• The jets from X-ray binaries are very similar to
  those from AGN
• Relativistic bulk motions with ? gt 1
• Composition of relativistic (??gt 100, in some
  cases gt106) leptons observed via their
  synchrotron radiation
• Have an important feedback effect on their
  environment
• Powered by central accreting black hole (or
  neutron star)
• If we assume that this similarities have a
  common physical origin, we can use one to learn
  about the other

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GRS 1915105 a super-Eddington 15 solar mass BH
MERLIN observations
receding
Daily images Proper motions are so high (compare
10s of mas/day with few mas/year) because of
distance ratio (not mass scaling)
600 mas 6000 A.U. at 10 kpc
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The jets may be just as relativistic as those
from AGN XRB AGN (Jorstad) Miller-Jones, Fender
Nakar (2006)
Lorentz factors of XRBs estimated from limits on
jet opening angle

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Jet-blown bubbles in the ISM Cygnus X-1
Emin 1048 erg
Gallo, Fender, Kaiser et al. 2005
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What weve really learned that would have been
difficult / impossible from AGN alone, is the
properties of the discjet coupling in accreting
black hole systems. AND nearly everything weve
learned from 10 solar mass BH seems to be
applicable to supermassive BH in AGN so far
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So what is the relation to jets ?
From quiescence to the brightest hard X-ray
states, there seems to be a steady, powerful, jet.
1.0
0.1
0.01
X-ray Luminosity / Eddington
Steady jets (1014 cm)
lt10-6
Quiescence
soft spectrum
hard spectrum
hardness
X-ray
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So what is the relation to jets ?
In steady soft X-ray states there appears to be
no jet produced
1.0
0.1
0.01
X-ray Luminosity / Eddington
lt10-6
Quiescence
soft spectrum
hard spectrum
hardness
X-ray
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Hard state Lradio ? LX0.7 (and if Lradio
??PJ1.4 ? PJ ??LX0.5 )
Gallo, Fender Pooley (2003) Gallo, Fender et
al. (2006)
LX (Edd)
Gallo, Fender Pooley (2003) Gallo,
Fender et al. (2006)
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Why this relation to states ? MHD jets and B
scale height ?
Low/hard X-ray state Power-law spectrum,
cutoff 100 keV Jets always present, lots of
variability These are the states modeled as ADAFs
B field
Accretion disc
"Corona" (base of jet?)
B field
High/soft X-ray state Thermal spectrum, no
sign of jet (in radio) Very little
variability Probably globally radiatively
efficient ?
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Early on in a major outburst, a large-scale, very
powerful jet is produced
1.0
Outburst
0.1
Around this point strong and variable QPOs appear
(e.g. Casello, Belloni Stella 2005)
0.01
Discrete ejections (up to parsec scales)
X-ray Luminosity / Eddington
lt10-6
soft spectrum
hard spectrum
X-ray
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Powerful jets produced in transition from
canonical low/hard to high/soft states
Corbel et al. 2002
Gallo et al. 2004
Fender, Belloni Gallo (2004) See also Corbel et
al. (2004) Homan Belloni
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What causes transient jet? This is formed as
source moves between classical hard and soft
X-ray states.
GX339-4
Fits to X-ray spectra invariably indicate that
this corresponds to the point of minimum inner
disc radius (which is often sustained for a
period of gt100 days)
radio flare

• The optically thin radio flares occur around the
  time that the optically thick accretion disc
  reaches its innermost radius
• but why ? ? ?

(e.g. Zdziarski et al. 2004)
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Towards a unified model
More powerful, hard sources have more powerful,
steady jets
As source softens, jet velocity increases
abruptly, causing internal shock in jet
Some sources do this more than once
1915?
1859, 1550?
Only crossing the jet line from hard to soft
makes an outburst !!
Subsequently, soft states show no jet
Faint, hard source have steady, ?1 jets
Crossing from soft to hard (e.g. ? quiescence)
there is no shock
1915 Fender Belloni (2004)
Generic Fender, Belloni Gallo (2004)
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• Some considerations, additions and refinement
  since the model came out
• The HIDs are not always as simple as we show but
  the general pattern is not strongly violated
  (Homan Belloni 2005). Hard to soft transitions
  may occur at different luminosities, and the jet
  line transition may occur at a different
  hardness.
• 2. The timing properties of the sources also show
  a close association with jet production in
  particular there may be particular QPOs
  associated with the transition around the jet
  line (Homan Belloni 2005 Remillard 2005
  Casella et al. 2005)
• 3. Is there a fast spine even in the hard state
  ? This might reconcile XRBs with blazars and is
  included in the model of Petrucci et al. (2006,
  on astro-ph)

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• Where does all the power go ? using the disc-jet
  coupling to test advection
• The overwhelming majority of jet formation is
  taking place in the hard state, which is also the
  state modeled as being an ADAF. (and also the
  state in which most black holes find themselves
  most of the time). Issues
• Are both processes (jet production and
  advection) occurring together ? probably
• Do they dominate over radiation, so that
  accretion flow is radiatively inefficient ? maybe
• Which one, jet or advection across event
  horizon, is the dominant sink for non-radiated
  accretion power ? ? ? ?

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X-ray binaries provide us with a further
advantage over AGN a control sample with very
similar spacetime, but a solid surface neutron
stars Comparing the disc-jet coupling in BH and
NS XRBs BH Lradio ???LX0.7 NS Lradio
????LX1.4 which implies (with liberal use of
Occams razor) BH Pjet ??m , LX???m2 NS
Pjet ? m , LX ??m
(Migliari Fender
2005)
.
.
.
.
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Quantifying what this all means We (Koerding,
Fender Migliari) have developed a method to
measure accretion rate from radio luminosity. We
find that the normalisation is almost the same
for BH and NS (? as noted previously you dont
need a black hole to make a relativistic
jet) Using this method, we can test the
dependence of X-ray luminosity on accretion rate
for any object for which we have a measure of LX
and Lradio
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Koerding, Fender Migliari (2006)
Using Lradio as m tracer, BH are clearly
radiatively inefficient
.
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Well then, what about AGN ? ?
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How does this relate to the fundamental plane
() of black hole activity ? Actually, the
plane almost exactly as measured -- emerges as
a natural and intuitive consequence IF Lradio
??m1.4 and (LX /M) ??(m/M)2 then Lradio ?
LX0.7 M0.7 which only differs from observed plane
by M0.15 recently the subject of some
Michigan-based scepticism
.
.
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With this M0.15 mass correction applied
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Following this approach, we can establish (we
would claim) that all hard state BH (lt2 Edd),
whether XRB or AGN are jet-dominated advective
systems in which Pjet gt LX and QADAF
Pjet Furthermore, the correspondence between
hard state BH XRBs and (LL)AGN of widely varying
masses implies that transition from radiatively
efficient to inefficient accretion occurs at
about the same Eddington ratio in all
BH (Koerding, Fender Migliari 2006
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The Bottom Line X-ray binary jets are very much
like the jets from AGN relativistic, powerful,
powered by accretion By studying the temporal
variability of XRBs we can gain insights into the
response of an accreting black hole to a varying
accretion rate which are impossible via the study
of AGN alone The comparison with NS has proved
invaluable, and has revealed that most accreting
BH should be jet-dominated advective systems