Pulsars with NenuFAR: backend and pipelines

Abstract

NenuFAR (New extension in Nançay upgrading LoFAR) is a new radio telescope developed and built on the site of the Nançay Radio Observatory. It is designed to observe the largely unexplored frequency window from 10 to 85\,MHz, offering a high sensitivity across its full bandwidth. NenuFAR has started its "early science" operation in July 2019, with 58\% of its final collecting area being available. Pulsars are one of the major topics for the scientific exploitation of this frequency range and represent an important challenge in terms of instrumentation. Designing instrumentation at these frequencies is complicated by the need to compensate for the effects of both the interstellar medium and the ionosphere on the observed signal. Our real-time pipeline LUPPI (Low frequency Ultimate Pulsar Processing Instrumentation) is able to cope with a high data rate and to provide real-time coherent de-dispersion down to the lowest frequencies reached by NenuFAR (10\,MHz). The full backend functionality is described, as well as the main pulsar observing modes (folded, single-pulse, waveform, and dynamic spectrum). This instrumentation allowed us to detect 172 pulsars in our first targeted search below 85\,MHz, including 10 millisecond pulsars (6 of which detected for the first time below 100 MHz). We also present some of the "early science" results of NenuFAR on pulsars: a high frequency resolution mapping of PSR B1919$+$21's emission profile and a detailed observation of single-pulse sub-structures from PSR~B0809$+$74 down to 16\,MHz, the high rate of giant-pulse emission from the Crab pulsar detected at 68.7\,MHz (43 events/min), and the illustration of the very good timing performance of the instrumentation, allowing us to study dispersion measure variations in great detail.

13 pages, 14 figures, submitted to A&A

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Cited by in corpus (14)

• Dual-frequency single-pulse study of PSR B0950+08
• Pulsar scintillation studies with LOFAR. I. The census
• Status Report on Global Pulsar-Timing-Array Efforts to Detect Gravitational Waves
• A broadband radio study of PSR J0250+5854: the slowest-spinning radio pulsar known
• First Results from the REAL-time Transient Acquisition backend (REALTA) at the Irish LOFAR station
• Constraining the magnetic field geometry of the millisecond pulsar PSR~J0030+0451 from joint radio, thermal X-ray and $\gamma$-ray emission
• The polarization of the drifting sub-pulses from PSR B1919+21
• Pulsar Scintillation Studies with LOFAR: II. Dual-frequency scattering study of PSR J0826+2637 with LOFAR and NenuFAR
• Broadband Polarized Radio Emission Detected from Starlink Satellites Below 100 MHz with NenuFAR
• A double dipole geometry for PSR~J0740+6620
• Impact of the observation frequency coverage on the significance of a gravitational wave background detection in PTA data
• Observing Jupiter's radio emissions using multiple LOFAR stations: a first case study of the Io-decametric emission using the Irish IE613, French FR606 and German DE604 stations
• Improving DM estimates using low-frequency scattering-broadening estimates
• 50-250 MHz Pulsar Census with an SKA-Low prototype station: Spectra and Polarization