Radio Observations (VLA)

The pre-existing high-quality radio maps of PKS 2354-35 were taken with the VLA in its A- and B-array configurations at 8.5GHz and 4.8GHz (Taylor et al. 1994). Such maps may well miss low surface brightness structure on the arcmin scale, such as could exist within the observed X-ray cavities of A 4059. With this motivation, we obtained new VLA data optimized to study structures on the size scale of the X-ray cavities. In detail, we made continuum flux maps of PKS 2354-35 using the VLA-CnB configuration at 6 and 20 cm. We observed PKS 2354-35 for 37 minutes at C-band with a 50 MHz bandwidth centered at $\nu = 4.7351$ GHz and for 31 minutes at L-band with a 50 MHz bandwidth centered at $\nu = 1.4149$ GHz. PKS 2354-35 is a southern source at $\delta$ = $-$34$^h 45^m 30^s$ hence the use of the northern extension, CnB. We were not able to make polarization maps from these data because the restricted time range over which the observations were made meant that no polarization calibrators were available. These VLA data were reduced using standard AIPS methods. The resultant clean beams for natural weighted maps are fairly elongated: the L-band (1.4GHz) beam had a major axis of $20.3''$ and a minor axis of $14.5''$ while the major axis of the C-band (4.7GHz) beam was $6.2''$ and the minor axis was $4.0''$.