The MeerKAT Telescope as a Pulsar Facility: System verification and early science results from MeerTime

Abstract

We describe system verification tests and early science results from the pulsar processor (PTUSE) developed for the newly-commissioned 64-dish SARAO MeerKAT radio telescope in South Africa. MeerKAT is a high-gain (∼ 2.8 K/Jy) low-system temperature (∼ 18 K at 20cm) radio array that currently operates from 580-1670 MHz and can produce tied-array beams suitable for pulsar observations. This paper presents results from the MeerTime Large Survey Project and commissioning tests with PTUSE. Highlights include observations of the double pulsar J0737−3039A, pulse profiles from 34 millisecond pulsars from a single 2.5 h observation of the Globular cluster Terzan 5, the rotation measure of Ter5O, a 420-sigma giant pulse from the Large Magellanic Cloud pulsar PSR J0540−6919, and nulling identified in the slow pulsar PSR J0633-2015. One of the key design specifications for MeerKAT was absolute timing errors of less than 5 ns using their novel precise time system. Our timing of two bright millisecond pulsars confirm that MeerKAT delivers exceptional timing. PSR J2241−5236 exhibits a jitter limit of < 4 ns per hour whilst timing of PSR J1909−3744 over almost 11 months yields an rms residual of 66 ns with only 4 min integrations. Our results confirm that the MeerKAT is an exceptional pulsar telescope. The array can be split into four separate sub-arrays to time over 1000 pulsars per day and the future deployment of S-band (1750-3500 MHz) receivers will further enhance its capabilities.

Measurements of pulse jitter and single-pulse variability in millisecond pulsars using MeerKAT

“…The MeerKAT radio telescope is the South African precursor for the Square Kilometre Array (SKA) mid radio telescope located in the Great Karoo region, and is capable of observing the large population of known pulsars in the Southern and Northern hemispheres. The MeerTime collaboration (Bailes et al 2020) is one of the MeerKAT Large Survey Projects, which has been provisionally awarded many months of observing time. The MPTA is one of the four major science themes as part of MeerTime, which focuses on the precision timing of MSPs and is poised to contribute to an internationally coordinated effort to detect the stochastic gravitational wave background using pulsar timing arrays through the International Pulsar Timing Array (IPTA, Hobbs et al 2010;Verbiest et al 2016;Perera et al 2019).…”

“…Search-mode applications (for single pulses) on the other hand, use to produce high time resolution spectra (filterbanks) data products. A detailed description of the MeerKAT pulsar timing infrastructure including polarisation calibration is provided in Bailes et al 2020. For the analysis presented here however, we only used the total intensity profiles.…”

“…The reference signal produced by the incoherent sum of the noise diode signals in the MeerKAT array cannot be used to calibrate the absolute gain, differential gain and differential phase of the system as it deviates from 100% linear polarization (Bailes et al 2020). However, the differential gain is calibrated to within 1% during the procedure that is used to phase up the tied array, leaving only the absolute gain and differential phase to be calibrated.…”

Evaluating Low-Frequency Pulsar Observations to Monitor Dispersion with the Giant Metrewave Radio Telescope

“…IPTA data releases are comprised of data from all eight radio telescopes used by these three regional collaborations. As more pulsar observing instruments have come online, additional regional PTA efforts are developing (e.g., Hobbs et al 2019;Bailes et al 2020). The inclusion of more instruments into the IPTA can aid in producing a more valuable dataset by increasing the number of MSPs, the number of TOAs, the sky coverage, and observing frequency coverage.…”

Eight new millisecond pulsars from the first MeerKAT globular cluster census

“…Two MeerKAT Large Survey Projects (LSPs) that include science of pulsars in GCs as part of their main scientific goals have already been approved and commenced. The first one to start was MeerTime 3 (Bailes et al 2020), which began collecting data in early 2019. The project has a variety of scientific objectives, one of these is the exploitation of GC pulsars through pulsar timing and polarimetry.…”