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Compact radio jets and nuclear regions in galaxies

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Title: Compact radio jets and nuclear regions in galaxies


1
Compact radio jets and nuclear regions in galaxies
Andrei LobanovMax-Planck-Institut für
Radioastronomie
8th European VLBI Network SymposiumTorun, 26-29
September 2006
2
Outline
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

3
Jets 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.

4
Anatomy of Jets
5
Cores 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
6
Collimation 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)

7
Shocks 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
8
Shocks 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
9
Instabilities 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, Martí
2006
10
Instabilities 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
11
Jet disruption on kpc scales
A. Lobanov
0836710
Lobanov et al. 2006
Perucho, Lobanov, Martí 2007
12
Jets and Nuclear Regions
13
Jets 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

14
Properties of BBH in 3C345
A. Lobanov
(Lobanov Roland 2005)
15
Disk 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
16
Nuclear 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
17
Nuclear 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
18
Nuclear 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
19
Physics from the core shift
A. Lobanov
  • Pressure and density profile in the broad-line
    regions magnetic field distributions in compact
    jets

3C345
Lobanov 1998
20
Disk-Jet Connection 3C120
A. Lobanov
(Marscher et al. 2002)
21
Jet-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
22
Jet-BLR connection
A. Lobanov
  • The jet in 3C390.3 may power a BLR associated
    with a subrelativistic outflow from the
    nucleus.

23
Summary
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.
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