Pulsar timing can reach very high accuracy. This makes millisecond pulsars (MSP) excellent probes to analyze their physical environment. In particular, pulsar timing arrays (PTAs), conformed usually by tens of precisely-timed MSPs, can be used as a Galactic scale detector of low-frequency gravitational waves.
Bright MSPs, such as PSR J0437-4715, are excellent targets for IAR's antennas. We are currently performing an almost four-hours per day monitoring of PSR J0437-4715 at 1400MHz. These observations are projected to increase the sensitivity of NANOGrav PTA by a factor of 2-3 to different supermassive black hole binary (SMBHB) systems by providing an overall sky coverage that takes care of NANOGrav's ``blind spot'' on the Southern Hemisphere.