Approaching NGC 3079 with VLBI

1
Approaching NGC 3079 with VLBI (Are Seyfert Jets
Green?)
Enno Middelberg MPIfR, Bonn
In collaboration with T. P. Krichbaum A. L.
Roy A. Witzel J. A. Zensus
2
Introduction Motivation
-Radio loud vs radio quiet Seyfert "jets"
intrinsically slow? -Spectra? -Variability? -Br
ightness temperatures?
3
Introduction NGC 3079 facts
Distance 15 Mpc Scale 0.07 pc / mas AGN
type Seyfert 2 / LINER Nucleus 106 M (H2O
maser) Optical Ha filaments "Superbubble"
X-Ray aligns with Ha Radio kpc double
lobes OH absorption CO circumnuclear
disk pc aligned components
4
Observations
Nov 1999 / Apr 2000 / Nov 2000 VLBAEffelsbe
rg _at_ 1.7 / 5 / 15 GHz Sep 2002 VLBA _at_ 1.7 /
2.3 / 5 GHz, ?-ref, polarimetric Effelsberg at
1.7 GHz for matching resolution
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Results
X
B
B
N
C
5 GHz, j-ref, Sep 02
15 GHz, Nov 00
A
A
X
X
N
N
2.3 GHz, j-ref, Sep 02
1.7 GHz, j-ref, Sep 02
A
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Results
7
Discussion Spectra
Spectral variability
B
A
8
Discussion Spectra
X
Free-free absorption? Fit yields aintr
-4.59 ne2 L 57 106 pc cm-6 Several
absorption mechanisms! Supernova? Possible, but
uncertain
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Discussion Proper motion
0.48 0.02 mas/yr 0.12 0.012 c
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Discussion Proper motion
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Discussion Statistics
Proper motion generally lt 0.5 c
Spectra 10/13 have flat / inverted VLBI
components Misalignment 8/11 are
misaligned by more than 15
Misalignment
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Summary

1. NGC 3079 observed during 4 epochs at 4
   frequencies
2. Spectral variability
3. Extreme spectra in off-axis component. Supernova?
4. Proper motion of 0.12 c characteristic for
   Seyferts
5. Core position unclear, later j-ref needed to
   decide
6. Growing evidence Seyferts are intrinsically
   weak, slow and misaligned.