Scientific Priorities for ARGOS
To take into account the needs and desires of ARGOS non-science stakeholders, as well as the spirit and rules of the Horizon Europe call under which ARGOS-CDS is funded, the technical design should try to respect the following constraints
- Low-cost: The total hardware cost for hardware (antennas, RF, electronics, compute notes) shall not exceed 50 Million Euro in 2023 prices. The total cost for hardware and construction shall not exceed 60 Million Euro in 2023 prices. These numbers refer to an observatory with a total collecting area of ~30,000 m^2.
- Scalability: The unit cost – defined as the total hardware cost for the full array, divided by the number of elements – shall not exceed 50,000 Euros in 2023 prices.
- Modularity: In the context of ARGOS-CDS, the Consortium has agreed to develop three science pipelines for pulsar timing, imaging, and commensal FRB searches. However, the technical design should allow for possible future upgrades with new backends, ideally without affecting existing modules. This could be achieved, for instance, by having all backends subscribe to the same datastream.
- Private sector involvement: To the extent that it is possible, the technical design should provide incentives for the involvement of private companies. Similarly, the ARGOS-CDS should prioritise the development of software and technologies that could have spill-over benefits. In practice, this means incorporating COTS components in the design wherever possible, prioritising the development of algorithms that could be adopted for commercial applications (e.g. AI algorithms for image reconstruction and anomaly detections, optimization of data processing methods, etc.), testing and developing low-cost hardware fabrication methods, etc.
- Complementarity to other facilities To maximise its long-term impact, ARGOS should be complementary to other existing and planned facilities in terms of its location, sensitivity, frequency coverage and overall capabilities. A summary of relevant infrastructures is provided in Table 1.
- Environmental constraints The technical team should strive to minimise energy consumption and the overall environmental impact. Decommissioning of the instrument should leave no observable impact to the deployment site.
Table 1: List of Relevant Telescopes and Projects
Facility | Short Description |
MeerKAT(+) | SKA-MID precursor located in the Karoo Desert |
SKA | The Square Kilometre Array |
DSA-2000 | a concept for a 2000 x 5m interferometer covering the 0.7-1.5 GHz range |
BURSTT | Bursting Universe Radio Survey Telescope in Taiwan |
ASKAP | SKA-MID pathfinder |
LOFAR2.0 | The upgraded low-frequency array |
MWA | Murchison Wide-Field Array |
CHIME | Canadian Hydrogen Mapping Experiment |
CHORD | Canadian Hydrogen Observatory and Radio-transient Detector |
HiRAX | Hydrogen Intensity and Real-time Analysis eXperiment |
(ng)VLA | The next-generation Very Large Array |
Assumptions
General Capabilities
The following set of high-level capabilities are derived from the science priorities that were developed by the SWG during the early conceptual design phase. On a more practical level, it is important for ARGOS to have attributes of a well-rounded, versatile and future-proof observatory.
- Survey Speed Figure-of-Merit: >107 deg2 m4 MHz K-2
- Frequency Coverage: Approx. 2 GHz covering L-band and S-band (currently targeting 1-3 GHz)
- Simultaneous recording of two orthogonal polarizations
- Resolution: O(5 arcsec)
- EL/AZ tracking
- Rms noise/beam [10sec; thermal, assuming 100% of array used]: < 0.01 mJy
- Pulsar sensitivity [5 min, thermal, assuming 100% of array used: < 0.02 mJy at DM=100 pc/cm3 P=3 ms
- Instantaneous Field-of-View: 10 deg2 or larger
High-level specifications
The following specifications are sufficient to enable the aforementioned capabilities, while also respecting the project’s constraints for cost and environmental footprint:
- SEFD: < 3.6 Jy
- Receiver temperature: < 35K
- Aperture efficiency: >80%
- Number of elements: 1000–1200
- Element diameter: 6+/-0.5 m
Next steps in refining the Level 0 Science Requirements
- The community will be asked to develop and discuss science priorities that respect the constraints and capabilities described in Section 3 (< 4 months). These proposals will have the form of conference contributions
- All contributions will be presented and discussed in the ARGOS2023 workshop in late October and compiled in a proceedings volume soon thereafter
- The Argos Science Working Group will evaluate the proposed science priorities using a set of predetermined criteria and re-map them to the neal-final set of level 0 requirements (5-6 months)
- The level 0 requirements will be reviewed and finalised during the Preliminary Design Review
Ranking criteria for scientific priorities
The ranking of science goals within each scientific area will be evaluated against the following criteria:
- How fundamental is this scientific question? Is it going to lead to a significant advance in the field?
- How urgent is this scientific question? Is it something that should be addressed in the next five years to decade?
- What is the importance of radio measurements for the envisioned result? Can this scientific question be addressed by measurements at other wavelengths?
- How necessary is the ARGOS contribution for achieving this result? Can it be achieved by other radio facilities?
- What is the fractional ARGOS sensitivity required to fully address this scientific question?
- How important is a synergy between existing facilities and ARGOS to address this scientific question?
- Is there an established method/technique for producing the scientific product required for this result?
- Have the methods for extracting the required measurements from the scientific product been established?
- Are there risks related to uncertainties in our understanding of the underlying physical phenomena and/or astrophysical sources?
