Daily Image
19-08-2014
A day in the life of a millisecond pulsar
| Submitter: | Cees Bassa, Gemma Janssen, Vlad Kondratiev, Jason Hessels, Roy Smits |
| Description: | On June 22 and 23rd, 2013 nine telescopes, spread around the world, joined together to observe a millisecond pulsar continuously for 24 hours. The Parkes telescope in Australia started the campaign, subsequently handing over to the GMRT in India, the European telescopes in Germany (Effelsberg), France (Nancay), the United Kingdom (Lovell) and the Netherlands (both WSRT and LOFAR), to end with Arecibo and Green Bank in the United States. This project was undertaken for the International Pulsar Timing Array (IPTA), which uses a set of accurately timed millisecond pulsars to directly detect gravitational waves. The millisecond pulsar chosen for this project is PSR J1713+0747. This pulsar is the most precisely timed pulsar in the IPTA project. The primary goal of this global observation is to characterize the timing noise of the pulsar on time scales ranging from one hour to one day. An overview of the project has recently been published. Though the focus of this global observing session was at observing frequencies around 1.4 GHz for studying timing noise, the unique capabilities of WSRT and LOFAR were used to obtain data at 350 MHz and 150 MHz, respectively. Observations at these low frequencies are crucial to study variations in the dispersion measure (a proxy for the electron column density towards the pulsar), which is one of the other main sources of noise in high precision pulsar timing. The top figure shows the J1713+0747 pulse profile at L-band (1.4 GHz, all telescopes except LOFAR), 350 MHz (WSRT) and 150 MHz (LOFAR). The pulsar is much weaker at lower frequencies, hence the lower signal-to-noise. The L-band/1.4 GHz dynamic spectrum is shown in the bottom panel. An intricate scintillation pattern is seen. The contributions of the different telescopes are indicated. |
| Copyright: | Cees Bassa |
| Tweet |  |