Forum Springer Astron. Astrophys.
Forum Whats New Search Orders

Astron. Astrophys. 364, L36-L41 (2000)

Previous Section Next Section Title Page Table of Contents

4. Summary and conclusions

The most important results can be summarized as follows:

  • emission lines of DIG can be traced out to 9 kpc in the halo of NGC 5775

  • the rotational velocity of the DIG drops from the rotational value at the midplane and approaches the systemic velocity at distances [FORMULA] 6.0 kpc

  • pure photoionization models are unable to reproduce the extreme line ratios of [OI ]/[FORMULA], HeI /[FORMULA], and [OIII ]/[FORMULA] as measured for the halo

  • a high degree of polarization and a strong vertical component of the magnetic field are observed in the halo. We found some, yet weak evidence for the dipolar magnetic field

  • a correlation exists between extraplanar DIG and magnetic fields, evidenced by the alignment of magnetic B-vectors with prominent halo features in the DIG and radio-continuum distribution

  • we suggest that reconnection processes play a substantial role in both heating the DIG structures in the halo and building up regular fields away from the disk plane

Previous Section Next Section Title Page Table of Contents

© European Southern Observatory (ESO) 2000

Online publication: December 15, 2000