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Some terminology: Regular magnetic field: a unidirectional one: RM 0 Pseudo-regular field: an anisotropic random one: <Bx 2 > > <By 2 > RM=0.
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Some terminology: Regular magnetic field: a unidirectional one: RM0 Pseudo-regular field: an anisotropic random one: <Bx2> > <By2> RM=0 • Magnetic fields in perturbed galaxies: a sensitive measure of external influences • or • Why to observe abnormal galaxies when we don’t yet fully understand normal ones?
15% 10% 40% 1% NGC 4038/39 4.85 GHz DSS+TP+B-vec A merging pair Fundamental work by Chyży & Beck 2004,
NGC 4038/39 4.85 GHz DSS+TP+B-vec A merging pair Fundamental work by Chyży & Beck 2004, Highly polarized „collisionregion” Low-polarization hidden SF region Highly polarized, steep spectrum outflow region
a magnetic bridge? TP conts + PI B-vecs Drzazga, Chyży in prep. NGC 877
NGC4490/85 another interacting pair Knapik et. al. in prep. Late type, no AGN
NGC 4490/85 a magnetized stream?? HI image: Clemens, Alexander, Green 1998
PV along this line and analogous along the NW arm Soida et al. 2001`
NW normal region Diffuse CO(1-0) gas IRAM dish (Reuter et al. 1996) Clumpy CO(1-0) gas OVRO interf. (Soida et al. in prep) SE abnormal region Diifuse CO gas Clumpy CO gas
Colour – clumpy cool gas seen by OVRO, conts – IRAM 1-0 upper panel: polarized intensity Colour – clumpy cool gas seen by OVRO, conts – HHT 3-2 upper panel: polarized intensity Data: OVRO –M. Soida, IRAM – Reuter et al. 1006 CO(3-2) HHT – Krakow + Bonn (M. Dumke, M. Krause, R. Wielebinski), in prep. A very personal remark: Without polarization observations probably these anomalies would remain unnoticed? Soida et al. in prep.
Stephan’s Quintet IR – Appleton et al. Spitzer gallery X-rays – Trinchieri et al.. 2003
Bt = 7G Bu = 1.5 G Bt = 8G Bu = 2G Soida et al. in prep. Genuine intergalactic (quasi) regular magnetic field TP conts+PI B-vecs VLA 6cm
15% 85% Motion? NGC 4501 in the Virgo Cluster TP+PI B-vecs, VLA 6cm Vollmer et al. 2007 + Kraków+Bonn& NRAO teams
NGC 4501 rectified: Assymmetry of the magnetic pitch angles Data from Vollmer et al. 2007 + Kraków+Bonn & NRAO teams
Polarization used to constrain the model Vollmer et al. (incl. Krakow, Bonn &NRAO teams) 2008 Pmax=2000cm-3(km s-1)2 twind= 80Myr
Colour - HI ???? NGC 4654 TP contours +PI vecs VLA 20cm Radio data Vollmer et al. 2007 (incl. Krakow, Bonn & NRAO teams) HI Phookun & Mundy 1995.
NGC 4535 – in southern Virgo extension – a „no reason” face-on case Vollmer et al. (incl. Krakow, Bonn & NRAO teams) 2007 Galaxy motion? NGC 4402 blown from the bottom? TP conts + PI vecs VLA 6cm Edge-on „no reason” case
Motion? M86 environment NGC 4438 H (red) Kenney et al. 2008 X-rays (green) M. Weżgowiec from archive NEWTON-XMM data
Attempt to summarize • We have observed: • Magnetic bridges • Anomalous arms • Compressional ridges • Magnetized outflows • Intergalactic magnetic fields Magnetic field as seen in polarization is a very good „preselector” of anomalies to be studied in detail in other domains (X-rays, HI dynamics etc.)