Distribution of polarised radio emission in M31
Abstract
Observations yielding the distribution of large-scale magnetic fields in nearby spiral galaxies are still extremely scarce. Optical polarisation of starlight has been observed in the disks of M31, M51, M81 and some other spiral galaxies1-3, but these measurements are too few to reveal the general distribution and direction of the magnetic fields. Segalovitz et al.4 observed the distribution of the polarised radio emission in M51 at λ21 cm and λ6 cm with sufficient linear resolution (2.6 × 3.6 kpc) and sensitivity to conclude that the magnetic field in M51 is predominantly directed along the spiral arms. The first results of detailed polarisation measurements of the emission of M31 at λ11 cm (ref. 5) indicated that in the southern part of the bright ring of radio emission the magnetic field is generally aligned along the ring. We show here that this early conclusion seems to hold for the whole of the ring.
- Publication:
-
Nature
- Pub Date:
- January 1980
- DOI:
- 10.1038/283272a0
- Bibcode:
- 1980Natur.283..272B
- Keywords:
-
- Andromeda Galaxy;
- Brightness Temperature;
- Galactic Radio Waves;
- Interstellar Magnetic Fields;
- Polarized Electromagnetic Radiation;
- Radio Astronomy;
- Spiral Galaxies;
- Astronomical Maps;
- Polarization Characteristics;
- Radio Sources (Astronomy);
- Astrophysics