The NSAS General Meeting for February will be on Tuesday the 18th February at 7:30 PM at Regis Hall, Regis Campus, St Ignatius College, Lane Cove.

Our speakers this month are Pero Manojlovic and Rami Alsaberi from Western Sydney University. They will give a presentation from their PHD theses. See abstract below.

As usual, visitors are most welcome!

Cheers
David Wallace

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Abstracts:

Working with ATCA, ASKAP, and their large surveys
Australia is home to some of the worlds leading radio telescopes such as Parkes, the Murchison Widefield Array (MWA), the Australia Telescope Compact Array (ATCA) and most recently the Australian Square Kilometre Array Pathfinder (ASKAP). ATCA and ASKAP especially excel at surveys as we have seen recently with projects such as GLASS and the Evolutionary Map of the Universe (EMU). In this talk I will present results obtained by analzying data from both of these instruments, namely samples of radio galaxies, clusters, Bent-Tail galaxies and other AGN which has comprised my PhD project so far. Studies on surveys such as these are essential for larger upcoming projects such as EMU’s near fullsky survey which will observe over 70 million radio sources in the sky.

Discovery of a Pulsar-powered Bow Shock Nebula in the Small Magellanic Cloud Supernova Remnant DEM S5
We report the discovery of a new Small Magellanic Cloud Pulsar Wind Nebula (PWN) at the edge of the Supernova Remnant (SNR) DEMS5. The pulsar powered object has a cometary morphology similar to the Galactic PWN analogs PSR B1951+32 and `the mouse’. It is travelling supersonically through the interstellar medium. We estimate the Pulsar kick velocity to be in the range of 700-2000 km/s for an age between 28-10 kyr. The radio spectral index for this SNR-PWN-pulsar system is flat (-0.29 +- 0.01) consistent with other similar objects. We infer that the putative pulsar has a radio spectral index of -1.8, which is typical for Galactic pulsars. We searched for dispersion measures (DMs) up to 1000 cm-3 pc but found no convincing candidates with a S/N greater than 8. We produce a polarisation map for this PWN at 5500 MHz and find a mean fractional polarisation of P ~23 percent. The X-ray power-law spectrum (~2) is indicative of non-thermal synchrotron emission as is expected from PWN-pulsar system. Finally, we detect DEMS5 in Infrared (IR) bands. Our IR photometric measurements strongly indicate the presence of shocked gas which is expected for SNRs. However, it is unusual to detect such IR emission in a SNR with a supersonic bow-shock PWN. We also find a low-velocity \HI\ cloud of ~107 km/s which is possibly interacting with DEMS5. SNR DEMS5 is the first confirmed detection of a pulsar-powered bow shock nebula found outside the Galaxy.