Post on 14-Feb-2019
Microquasars
Gustavo E. RomeroInstituto Argentino de Radioastronomía (CONICET)
University of La Plata
romero@iar-conicet.gov.ar
romero@fcaglp.unlp.edu.ar
http://www.iar-conicet.gov.ar/garra/
1
São Paulo, FAPESP, August 9, 2011
4
Stellar black holes can also produce jets
SS 433
Radio (Dubner et al); X-rays (Brinkmann et al)
- ATOMIC NUCLEI MOVING AT 0.26c
- MECHANICAL LUMINOSITY > 1039
erg/sec
- NON RADIATIVE JETS = “DARK” JETS
- >50% OF THE ENERGY IS NOT
RADIATED
Be disk
NS or BH
overflow from Be disk
Accretion in Be/X-ray binaries
accretion disk
high energy emission
accretion
Romero et al. 2007, A&A
A “basic” jet model (in a nutshell)
Physical conditions near the jet base are similar to those of the corona (e.g. Bosch-Ramon et al. 2006; Romero & Vila 2008, 2009; Vila & Romero 2010)
The jet launching region is quite close to the central compact object (few Rg)
Thermal plasma injected at the base, equipartitionb/w particles and magnetic field to start with.
Jet plasma accelerates longitudinally due to pressure gradients, expands laterally with sound speed (Bosch-Ramon et al. 2006)
The plasma cools as it moves outward along the jet. Solve the continuity equation for cooling of the electron and proton energy distributions
A “basic” jet model (in a nutshell)
Physical conditions near the jet base are similar to those of the corona (e.g. Bosch-Ramon et al. 2006; Romero & Vila 2008, 2009; Vila & Romero 2010)
The jet launching region is quite close to the central compact object (few Rg)
Thermal plasma injected at the base, equipartitionb/w particles and magnetic field to start with.
Jet plasma accelerates longitudinally due to pressure gradients, expands laterally with sound speed (Falcke 1996, Bosch-Ramon et al. 2006)
The plasma cools as it moves outward along the jet. Solve the continuity equation for cooling of the electron and proton energy distributions
An application – Vila & Romero, extended-zone model, 2011
Fit to the spectrum of the LMMQ XTE J1118+480
2000 outburst
-5 0 5 10 1528
29
30
31
32
33
34
35
36
37
Log10
(E /eV)
Lo
g 10(L
/er
g s
-1)
disc
synchrotron
SSC
pp
p
Fermi
VERITAS
CTA
LLAMA
The black hole in the Galactic CenterSgr A* Spectrum
Mościbrodzka, Gammie, Dolence et al. (2009)
The physical model is a
geometrically thick, optically thin,
turbulent plasma accreting
onto a rotating black hole in a
statistically steady state. The
angular momentum of the
hole is assumed to be aligned with
the angular momentum of the
accreting plasma.
The ions and electrons are
assumed to have a thermal
distribution function, but with a
temperature ratio Ti/Te that may
be different from one
Future mm-VLBI
Existing facilities:
JCMT, CARMA, SMT, SPT
SPT-JCMT: 15.000km (~5µas)
Under construction:
LMT, ALMA
New ones?
LLAMA (Argentina)
Peru …?
21
Images of the accretion flow at
230 GHz for models with SEDs
that are consistent
with observations of SgrA*. The
images have been averaged over
time and over four separate
realizations of each model. The
images show inner 40GM/c2 .
The white circle marks
FWHM=37 µas of a symmetric
Gaussian brightness profile
centered at the image centroid.
Simulated 350 GHz VLBI
Scatter-Broadened best-fit Model Reconstructed Image
PSF
a=0.94, i=85°, Tp/Te=3
Mościbrodzka, Gammie, Dolence et al. (2009)
Final comments MQs produce gamma-rays, likely in the jets. This emission is
related to the sub-mm synchrotron radiation.
The consistency of the models outlined can be tested with present and future sub-mm, gamma-ray and neutrino observations (LLAMA, IceCube, Fermi, CTA…).
MQs can be sources of comic rays up to energies of the order of the knee (Auger infield array).
Absoption effects: annihilation (Vila & Romero 2011)
Log10
(z /cm)
Lo
g 10(E
/eV
)
9.5 10 10.5 11 11.5 12 12.5 13
-8
-6
-4
-2
0
2
4
6
8
10
Lo
g10 (N
/ erg-1 cm
-3)
-15
-10
-5
0
5
10
15
20
25
30
Log10
(z /cm)
Lo
g 10(E
/eV
)
9.5 10 10.5 11 11.5 12 12.5 13-6
-4
-2
0
2
4
6
8
10
12
14
exp
(-)
0.86
0.88
0.9
0.92
0.94
0.96
0.98
1
Log10
(z /cm)
Lo
g 10(E
/eV
)
9.5 10 10.5 11 11.5 12 12.5 13
-8
-6
-4
-2
0
2
4
6
8
10
Lo
g10 (N
/ erg-1 cm
-3)
-15
-10
-5
0
5
10
15
20
25
30
35
Log10
(z /cm)
Lo
g 10(E
/eV
)
9.5 10 10.5 11 11.5 12 12.5 13-6
-4
-2
0
2
4
6
8
10
12
14
exp
(- )
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
High-mass donor star: Cygnus X-1
Romero, del Valle, & Orellana, 2010, A&A 518, A12; see also
Bosch-Ramon, Khangulyan & Aharonian, 2008, A&A, 489, L21
External absorption
A microquasar with a clumped wind
34
Araudo, Bosch-Ramon & Romero A&A, 503, 673 (2009),
Owocki et al. 2009, ApJ, 696, 690 (2009)
35
MA
GIC
HE
SS
Cygnus X-1
LSI+61303
LS 5039
Flaring TeV emission?
Season I + Season II
If the wind has a clumpy structure,
then jet-clump interactions can
produce rapid flares of gamma-rays
Romero et al. 2007, astro-ph/0708.1525
A microquasar with a clumped wind
38Araudo, Bosch-Ramon & Romero A&A, 503, 673 (2009)
Local particle re-acceleration