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APERTIF Time-Domain DR1

APERTIF Time-Domain DR1

    Introduction

    We here present the 2019 data release for ARTS, the Apertif Radio Transient System, a supercomputing radio-telescope instrument that performs real-time Fast Radio Bursts detection and localisation on the Westerbork Synthesis Radio Telescope (WSRT) interferometer. The release includes the downsampled time-domain data from all pointings up to 31 Dec 2019. This snapshot of the fast-transient sky can be interesting for validation and searching for pulsars and Fast Radio Bursts. For details on observing and data, see: van Leeuwen, J. et al. “The Apertif Radio Transient System (ARTS): Design, Commissioning, Data Release, and Detection of the first 5 Fast Radio Bursts”, 2023,A&A, here.

     

    Observations & Processing

    Released Observations

    All raw downsampled observational data from the time-domain survey taken up to 31 Dec 2019 are released. The data are 1-bit Stokes-I PSRFITS files, supplying 384 x 0.8MHz channels, at 2.048 ms time resolution . A full overview of the observations & processing (Fig. 1) can be found in van Leeuwen et al. (2023).  Five new FRBs were presented there. The archive data for those pointings are directly accessible. For other pointings the metadata is directly available, but the data itself first needs to be staged from tape. Access to that data can be requested via the helpdesk.

    Overview of ARTS observations and data processing.
    Figure 1. Overview of ARTS observations and data processing.

     

    Data Quality

    For a detailed description of the Compound-beam and Tied-array-beam Sensitivity, and of the RFI, see Sect. 7 of van Leeuwen et al. (2023). The five FRBs presented in that paper were discovered in raw, high-resolution data, but are also visible in this archived data (Fig. 2).

    Five FRB discoveries.
    Figure 2. Five FRB discoveries.

     

    Data Products

    Raw, down-sampled pointings

    The time-domain data are in PSRFITS format, with 1-bit sampling. The data are total intensity (Stokes I). For each pointing, all TABs are available. Data from before 2020 May 1 supply 384 channels of 0.8MHz each, with a time resolution instead of 2.048ms. Later data are archived using higher temporal and spectral resolution, and provide 768 channels of 0.4MHz each, every 0.8ms.

    Where to find the data

    The Apertif Time-Domain Data Release 1 (ARTS DR1) is hosted on the Apertif Long Term Archive and exposed to the community through the standard Virtual Observatory protocol. This section describes how the data products can be queried and accessed by using different applications.

    User Interfaces

    The science-ready data products are exposed through standard Virtual Observatory (VO) protocols to facilitate their access and exploration.

    The Apertif Time-Domain DR1 data is hosted on the Apertif Long Term Archive (ALTA) system. We recommend astronomers to use the VO interfaces for data discovery. These interfaces will redirect to ALTA file servers for data access where appropriate.

    The data published in the VO can also be accessed using a web browser at https://vo.astron.nl (how to access the data and the relevant explanation about various data services can be found here).

    Data Usage Policy

    Papers making use of this data should include the following acknowledgement:

    This work makes use of data from the Apertif system installed at the Westerbork Synthesis Radio Telescope owned by ASTRON. ASTRON, the Netherlands Institute for Radio Astronomy, is an institute of the Dutch Research Council (“De Nederlandse Organisatie voor Wetenschappelijk Onderzoek, NWO).

    In addition, they should cite the time-domain overview paper:

    van Leeuwen, J. et al. “The Apertif Radio Transient System (ARTS): Design, Commissioning, Data Release, and Detection of the first 5 Fast Radio Bursts”, 2023, A&A

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