Abstract
The CHANG-ES (Continuum Halos in Nearby Galaxies) survey of 35 nearby edge-on galaxies is revealing new and sometimes unexpected and startling results in their radio continuum emission. The observations were in wide bandwidths centred at 1.6 and 6.0 GHz. Unique to this survey is full polarization data showing magnetic field structures in unprecedented detail, resolution and sensitivity for such a large sample. A wide range of new results are reported here, some never before seen in any galaxy. We see circular polarization and variability in active galactic nuclei (AGNs), in-disk discrete features, disk-halo structures sometimes only seen in polarization, and broad-scale halos with reversing magnetic fields, among others. This paper summarizes some of the CHANG-ES results seen thus far.
Highlights
Observations of NGC 4845 resulted in a serendipitous radio detection [14] of a Tidal Disruption event (TDE) approximately one year after its hard X-ray outburst [15]
An example is NGC 3628 which shows bipolar radio emission perpendicular to the major axis via flatter spectral indices in comparison to the surrounding emission [5]. These results show the importance of both polarization and spectral index mapping in disentangling AGN-related emission from emission related to other processes
One of the most remarkable results from the CHANG-ES survey is the discovery of reversing magnetic fields in our galaxy disks and halos
Summary
CHANG-ES (Continuum Halos in Nearby Galaxies—an EVLA Survey) is a project to observe. The wide bandwidths, ∆ ν, of the VLA Such a survey feasible since the theoretical signal-to-noise (S/N) improves as 1/ ∆ν, all else being equal. This has opened up the possibility of exploring the magnetic fields in galaxy disks and halos for a well-defined galaxy sample. Notice that selection effects should be minor, the main one being the possibility that, by adopting a radio flux density limit, we could inadvertently be choosing galaxies with high SFRs. Table 1 reveals that our SFR range is quite typical of ‘normal’ spirals. Over 405 hours of VLA time were granted for this large project
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
