Title: Compact radio jets and nuclear regions in galaxies
1Compact radio jets and nuclear regions in galaxies
Andrei LobanovMax-Planck-Institut für
Radioastronomie
8th European VLBI Network SymposiumTorun, 26-29
September 2006
2Outline
A. Lobanov
- Observational studies of extragalactic
relativistic jets - Anatomy of extragalactic jets VLBI
cores collimation and acceleration
scales (103 RS) regions dominated by
strong shocks (10 pc) dissipation of
shocks and development of instabilities
(100 pc) kiloparsec-scale jets - Relation between the jets and the nuclear
environment in active galaxies
jets from supermassive binary black hole systems
probing absorbing material in the nucleus
connection to accretion disks and
broad-line emission
3Jets and AGN
A. Lobanov
Mbh 5108 M?
- Event horizon 1-2 Rg 10-5 pc
- Ergosphere 1-2 Rg 10-5 pc
- Corona 101 102 Rg 10-4 10-3 pc
- Accretion disk 101 103 Rg 10-4 10-2 pc
- Broad line region 102 105 Rg 10-3 1 pc
- Molecular torus gt 105 Rg gt 1 pc
- Narrow line region gt 106 Rg gt 10 pc
- Jet formation 102 Rg 10-3 pc
- Jet visible in the radio gt 103 Rg gt 10-2 pc.
4Anatomy of Jets
5Cores of jets
A. Lobanov
- Location at which jets become visible in radio
is most likely determined solely by t1
condition for synchrotron emission (Königl
1981).
Lobanov Zensus 1999
Zensus et al. 1995, Lobanov 1996, Klare et al.
2005
6Collimation and acceleration
A. Lobanov
- VLBI observations of compact jets in nearby
AGN provide strong evidence for
collimation on linear scales of 103 RG
and strong accelerations on sub-parscec scales
- Magnetically driven acceleration is a viable
explanation for the observed speeds
(Vlahakis Königl 2004)
7Shocks on pc scales
A. Lobanov
- Strong shocks are clearly present in jets on
small scales (several decaparsecs) from
polarization and distribution of the
synchrotron turnover frequency.
3C 273
Core
J1
J2
J1
Core
J2
Carrara et al. 1997
8Shocks on pc scales
A. Lobanov
- Shock dissipate rapidly while approaching
hectoparsec scales shock models can no
longer explain kinematic and spectral
evolution observed in jets on these scales
Lobanov Zensus 1999
9Instabilities on pc scales
A. Lobanov
- Linear regime of K-H instability
lHs18.0, lEs12.0, lEb14.0, lEb21.9
Gj2.1, Mj3.5, h0.02, aj0.53, vw0.21
Lobanov Zensus 2001, Perucho, Lobanov, MartÃ
2006
10Instabilities on kpc-scales
A. Lobanov
- On kiloparsec scales, jets are well
represented by MHD models e.g., models
for 3C31 (Laing Bridle 2002,2004), and M87
(Lobanov, Hardee Eilek 2003, 2006)
M87
C
HST
D
G
E
I
A
B
11Jet disruption on kpc scales
A. Lobanov
0836710
Lobanov et al. 2006
Perucho, Lobanov, Martà 2007
12Jets and Nuclear Regions
13Jets from binary SMBH
A. Lobanov
Sol, Pelletier, Asséo (1989), Lobanov Roland
(2005)
- Magnetically confined outflow from a binary
SMBH. Jet components are produced by
perturbations in the beam - Explains both evolution of a feature in the
jet and optical variability - Jet contains information about the dynamic
state of the binary
14Properties of BBH in 3C345
A. Lobanov
(Lobanov Roland 2005)
15Disk variability and flares
A. Lobanov
- Flares and ejections of new jet components in
3C345 may be related to the characterstic
instability timescales in the disk at 20-200
Rg
Lobanov Roland 2005
16Nuclear absorption
A. Lobanov
- Absorption due to several species, most notably
HI, CO, OH, HCO - HI absorption toward compact jets is an
excellent tool to probe nuclear regions on parsec
scales. - Good indicator of physical conditions of the
neutral gas(Pedlar 2004)
NGC 4151
0.6pc
Mundell et al. 2003
17Nuclear absorption
A. Lobanov
- 1946708 Absorption probed on scales of
100pc broad (200km/s) and narrow (50km/s)
likely from a gas in a rotating toroidal
structure.
Peck Taylor 2001
18Nuclear opacity Core shift
A. Lobanov
- Position offset of the optically thick core
of a VLBI jet can be used to estimate physical
conditions in the nuclear region of AGN
Core location
(Königl 1981)
Core offset measure
Derived magnetic field and distance from the
central engine to the core
Lobanov 1998
19Physics from the core shift
A. Lobanov
- Pressure and density profile in the broad-line
regions magnetic field distributions in compact
jets
3C345
Lobanov 1998
20Disk-Jet Connection 3C120
A. Lobanov
(Marscher et al. 2002)
21Jet-BLR connection
A. Lobanov
- BLRG 3C390.3 jet can produce a large fraction
of non-thermal continuum - Optical maxima correlate with the passages of
relativistic plasma through S1 - An X-ray minimum is found close to the ejection
epochs of C5 and C6
Arshakian et al. 2006
22Jet-BLR connection
A. Lobanov
- The jet in 3C390.3 may power a BLR associated
with a subrelativistic outflow from the
nucleus.
23Summary
A. Lobanov
- Jets are an excellent laboratory for AGN
studies - Small scale jets are dominated by shocks
- At larger scales, shocks dissipate, and
Kelvin-Helmholtz instability determines the
structure and dynamics of the flow - Elliptical and helical modes of K-H
instability are most prominent, leading to
eventual disruption of the flow - Magnetically confined outflows may preserve
information about the dynamic evolution of
the nucleus - Jets can be used as probes of nuclear regions
in AGN - Jet-BLR connection may exist and should be
investigated in detail.