Wednesday, 1 July 2020

21cm Radio Astronomy




The image above shows recent results from our 2m dish in Prospect looking at the 21 cm Hydrogen signal (with star positions superimposed).  It's plotted in galactic coordinates and represents data collected over a few months.  Red indicates H1 moving away from us; blue is Doppler shifted to higher frequencies as the H1 moves towards us.  Leaving the dish in a fixed position for one day gives a curved track as the Earth rotates. (For example the almost circular tracks in the slightly-lower right side arose when the antenna was close to the South Celestial Pole.  The Pointers and Southern Cross can be clearly seen near zero latitude.)     We did a talk on this project recently for AREG