1. With contributions from Shea Brown & Damon Farnsworth, UMN
PUSHING into the WHIM
Lawrence Rudnick, Univ. Minnesota, EVLA Wkshp 2008
With contributions from Shea Brown & Damon Farnsworth, UMN
and R. F. Cardoso, U WI
Work supported by NSF grant AST at UMN

2. Local pressure radio surface brightness
Mass distribution of shock heated gas (z=0)
Kang, Ryu, Cen, Song 2005 ApJ 620, 21

3. LSS Shocks Synchrotron
Chris Pfrommer, various
Conference proceedings

4. 2 Mpc

5. Finding diffuse - confusion

6. Finding diffuse - filtering

7. Finding diffuse - subtraction
Abell 1367

8. ~ EVLA D config
convolved to 8’ (2 Mpc)

9. Diffuse POLARIZATION as WHIM probe
RICH X-ray cluster
POOR, non-X-ray cluster

10. Finding diffuse polarization – undersampled reconstruction

11. Missing large scale

12. Polarized emission
Large AND small scale

14. Faraday clouds at high latitude?
► (<P>800) new diffuse source candidate. Symbols: clusters of galaxies Gal et al (AJ 125, 1064).
► Stokes Q image 350 MHz (see text to right), with (<P>800) contours overlayed. Green: ~0 rad/m2
Yellow: ~ 13 rad/ m2

15. EVLA & Polarization
EVLA

16. Depolarization Intrinsic disorder (no l dependence)
within beam (plane of sky)
along line of sight
Faraday rotation ( l2 dependence)
Within beam
Along line of sight in source
Across bandwidth

17. Faraday rotation within beam
CGPS
Figure 1.21: An image at   21 cm of effects of the diffuse Faraday Screen in the Milky Way. This image from the Canadian Galactic Plane Survey shows the spatial variations in polarisation posiion angle imposed by changes in the structure of the Galactic magnetic field and diffuse electrons distribution on scales of 10's of pc. The SKA allow this technique to be used on other galaxies to investigate the structure and generation mechanisms of galactic magnetic fields.
5” 1.5”
Laing et al. 2008
Volume 391, Issue 2, Pages
Structures of the magnetoionic media around the Fanaroff–Riley Class I radio galaxies 3C 31 and Hydra A
R. A. Laing 1★ , A. H. Bridle 2 , P. Parma 3 and M. Murgia 3,4

18. Internal (line of sight) depolarization
6cm 21cm
Anderson, Keohane, Rudnick 1995

19. Rotation across band λ1 λ2 λ0
P = Q + iU λ1 λ2 λ0

20. RM synthesis A&A 441, 1217-1228 (2005) DOI: 10.1051/0004-6361:20052990
Faraday rotation measure synthesis     
M. A. Brentjens - A. G. de Bruyn

21. RM movie of 3C33/Abell 150 field
available at

22. 1000

23. The EVLA niche – mixed thermal/relativistic

24. PUSHING into the WHIM