Science Priorities for a European Wide-Field Radio Interferometer

24 Oct 2023, 17:00 → 27 Oct 2023, 17:20 Europe/Athens

Foundation for Research and Technology - Hellas

ARGOS2023 - 24-27 October 2023 (Hybrid Workshop)
 

Astronomy is being transformed by public surveys performed with instruments that are searching the sky for multi-messenger signals with high speed and sensitivity, while delivering science-ready datasets to the community. While radio astronomy is not yet fully participating in this revolution, an instrument following the same philosophy, which would finally open the dynamic radio sky for exploration, is not only urgent but inevitable.

ARGOS is a concept for a leading-edge, low-cost, sustainable European astronomical facility that will finally realise this ambition, directly addressing multiple fundamental scientific questions, from the nature of dark matter and dark energy to the origin of fast radio bursts and the properties of extreme gravity, thereby satisfying urgent needs of the community. 

The project has recently entered a three-year detailed conceptual design phase which is supported by a Horizon Europe Infrastructure Development Grant. The overarching objective for the ARGOS conceptual design study  is to prepare fully for the subsequent rapid implementation of a leading-edge wide-field interferometer in Europe and ensure its optimal integration into the network of existing and future international astronomical facilities. 
 

Meeting Goals 

The workshop aims to bring together experts and stakeholders from various fields of astronomy to discuss the scientific potential and challenges of a future European wide-field radio interferometer. 

The workshop will cover topics such as:

• Recent advances and emerging themes in radio astronomy and transient astrophysics
• The science priorities for ARGOS
• The technical requirements and design options for the instrument: (configuration, data processing, calibration etc)
• The synergies and complementarities of ARGOS with other existing and planned radio facilities such as LOFAR, SKA, DSA2000, MeerKAT, ASKAP, FAST, Chime, etc.
• The roadmap and timeline for the development and implementation of ARGOS

 

The workshop will feature invited and contributed talks, posters, and panel discussions. Submissions that contribute to the development of the ARGOS Science Requirements will be compiled in a proceedings volume (the ARGOS blue book) after peer review.  

Format 

This will be a hybrid meeting. The ground event location is the Foundation for Research and Technology, Hellas in Crete, Greece. 

Themes

• Pulsars
• Pulsar Timing Arrays 
• Time Domain (slow Transients, technosignatures etc.) 
• Fast Radio Bursts 
• Imaging
• Cosmology 
• Very Long Baseline Interferometry
• Space and Commercial Applications
• Synergies
• Technology Pathfinding 
  
   

ARGOS Community Mattermost 

Contact: info@argos-telescope.eu 

 

Tuesday 24 October

18:00 → 22:00 Welcome Drink

Wednesday 25 October

09:00 → 10:00 Coffee & Tea

10:00 → 12:00 ARGOS-CDS: ARGOS Conceptual Design Study

10:00 The ARGOS project

TBD

Speaker: John Antoniadis (IA FORTH)

11:00 Backend system design for ARGOS

ARGOS is designed to carry out various types of scientific observations, from time domain to image domain, from spectroscopy to pulsar searching. A versatile, cost-effective and scalable backend system is essential to such a dense interferometer. In this report, we present a bottom-up backend system design for ARGOS pathfinder. It consists of processing units from the stages of digitalization, channelization, beamforming, correlation and data product distribution. The viability of these systems has been successfully proven in various astronomical instrumentation. The making of such a system will demonstrate its capability and gather the feedbacks from the scientific communities, providing valuable knowledges on scaling up the system from pathfinder to the full ARGOS implementation.

Speaker: Weiwei Chen (Max-Planck-Institut für Radioastronomie)

11:30 The ARGOS Frontend system

Speaker: Leonidas Marantis (UPRC)

12:00 → 13:00 Lunch Break

13:00 → 13:30 Multi-messenger Astronomy

13:00 Exploring continuous gravitational waves from pulsars

The LIGO-Virgo-Kagra Collaboration has revolutionized the field of astrophysics by successfully detecting transient gravitational waves from merging binary black holes and neutron stars. However, the search for continuous gravitational wave (CW) signals remains an ongoing challenge. Possible sources of this kind of signals are spinning neutron stars with a non-axisymmetric mass distribution producing persistent, nearly monochromatic, CWs over long periods. Different searches can be performed depending on our knowledge of the source parameters. To enhance the sensitivity of our search efforts, we leverage critical information derived from continued monitoring of pulsars related to the spin evolution, astrometry, and binary orbit. This information maximizes our ability to detect CW signals, in the so-called targeted searches. This talk provides an overview of LIGO-Virgo-Kagra CW science emphasizing the crucial role of pulsar parameters in targeted searches.

Speaker: Luca D'Onofrio (INFN Roma)

13:30 → 14:00 Multi-messenger Astronomy

13:30 Gravitaniotal wave counterparts in the radio band

The solitary binary neutron star merger, the first-ever detected through both gravitational waves and electromagnetic radiation, ignited an extraordinary international endeavor mobilizing over 70 ground-based and space telescopes. Remarkably, even after more than 1,200 days since its initial detection, we continue to observe the residual luminance from a formerly relativistic jet, gradually decelerating within the interstellar medium. This remarkable event has left an indelible mark on various aspects of scientific exploration, spanning from nuclear physics, extreme high-energy astrophysics, and gravitational physics to cosmology. In this presentation, we shall provide a comprehensive overview of the fundamental findings in these diverse domains, underscoring the profound implications and insights derived from our ongoing research efforts. Specifically, we will underscore the pivotal role played by the radio band in observing the afterglow of this neutron star merger. The radio observations have provided a unique perspective on the evolving nature of the jet, shedding light on its long-term behavior and interactions within the surrounding medium. Furthermore, VLBI imaging has set further insights into the structure and evolution of the relativistic jet. This binary neutron star merger event stands as a testament to the power of interdisciplinary collaboration and underscores the importance of multi-wavelength and multi-technique observations in unraveling the mysteries of the universe.

Speaker: Antonios Nathanail

14:00 → 17:30 Pulsar Timing and PTAs

14:30 The Thousand Pulsar Array: A large pulsar monitoring campaign on MeerKAT

We have been using MeerKAT in the last 4 years to observe a large population of slow rotating pulsars, with the objective to understand the pulsar population through a uniform, unbiased survey of a large number of sources. Uniformity in observing techniques and calibration, as well as processing pipelines and algorithms, allows us to extract parameters relating to these sources that can form the basis of population studies and that overcome problems of PSRCAT, the widely used ATNF pulsar catalogue. I will present a description of the programme, the technical challenges that we encounter and in particular the ones that required most effort to resolve. I will present an overview of the science results so far, motivating future programmes of this kind. ARGOS would be a fantastic instrument for an equivalent project in the era of SKA.

Speaker: Aris Karastergiou (Oxford)

15:00 Masses and precision tests of gravity with continuous pulsar timing

TBC

Speaker: Dr Paulo Freire

15:30 Pulsar timing at the Argentine Institute of Radio astronomy

The Argentine Institute of Radio Astronomy (IAR) is situated near the city of La Plata, Argentina. It is equipped with two 30-m single-dish antennas that are used exclusively for observations of pulsars and transients. Since 2018, the Pulsar Monitoring in Argentina (PuMA) group, has been using this antennas to conduct high-cadence observations of pulsars from the Southern hemisphere.
Several upgrades have been made to the antennas since the beginning of the campaign. The most recent one consists of the installation of new acquisition modules (ROACH) with 400 MHz of bandwidth. In this contribution, we present the main results of our research so far, including the detection and analysis of glitches, single pulses studies, and giant pulses in magnetars. We will also discuss our next goals and future perspectives, such as detecting a glitch live and contributing to gravitational wave astronomy.

Speaker: Ezequiel Zubieta (Argentine Institute of Radio astronomy / National University of La Plata)

16:00 Coffee & Tea

16:30 The future of PTA science

Speaker: Golam Shaifullah (University of Milan Bicocca)

17:00 Discussion about ARGOS pulsar timing requirements

17:30 → 18:00 ARGOS-CDS

17:30 Machine learning applications for ARGOS

Speaker: Samuel Farrens (CEA)

Thursday 26 October

09:00 → 10:00 Coffee & Tea

10:00 → 11:00 Site selection: Site Selection

10:00 Radio Frequency Interference: A European Radio Astronomy Perspective

10:30 RFI measurements in Crete

Speaker: Prof. Athanasios Kanatas (UPRC)

11:00 → 11:30 Time Domain

11:00 Testing the nature of possible milli-lens systems with ARGOS

The systematic search for gravitational lens systems on milli-arcsecond (mas) scales (milli-lenses) is the primary goal of the SMILE project (https://smilescience.info/). It will improve constraints on the number density of supermassive compact objects (SMCOs) in the universe by an order of magnitude compared to previous studies. These SMCOs potentially act as gravitational lenses for compact background AGN, making the otherwise dark lenses detectable. In turn, the study can constrain the abundance of compact, sub-galactic dark matter (DM) halos, possibly ruling out certain DM models.
Our study will be conducted by analyzing ~5,000 sources with very-long-baseline interferometry (VLBI) on mas-scales, based on the cosmic lens all sky survey (CLASS) with the VLA. Several tests will be applied to confirm or reject milli-lens candidates. If a system passes all our initial tests, ARGOS could possibly provide important additional constraints for these candidates.
In this talk, I will explain the scope of the project, the tests we are going to use to discriminate milli-lens systems, and show some preliminary results of a pilot search we have conducted. Then, I will go into the possible synergies with ARGOS.

Speaker: Felix Poetzl (Institute of Astrophysics - FORTH)

11:30 → 12:30 Open Discussion: Funding Opportunities

12:30 → 13:00 Lunch

13:00 → 18:00 Excursion to Skinakas Observatory and Nida Plateau

20:00 → 00:00 Dinner at Peskesi Restaurant

Friday 27 October

09:00 → 10:00 Coffee and Tea

10:00 → 12:00 Synergies

10:00 Real-Time All-Sky Camera for Compact Radio Arrays

Modern radio telescopes are envisioned to consist of hundreds to the thousands of antennas in order to meet various science requirements and in-turn raise the computational needs. Here we discuss a novel radio imaging concept called EPIC, that is particularly efficient for compact large-N radio arrays. EPIC has been successfully deployed on a GPU and demonstrated real-time imaging at the Long Wavelength Array (LWA) in New Mexico, USA. In this talk, I will discuss the EPIC all-sky imager, current developments and its potential application for upcoming radio telescopes including ARGOS.

Speaker: Hariharan Krishnan (Square Kilometer Array Observatory (SKAO))

10:30 Science with the Square Kilometre Array Observatory

The Square Kilometre Array (SKA, www.skao.int), currently under construction, will be the world’s largest radio observatory once completed. It will consist of one radio telescope operating in the 50-350 MHz frequency range (SKA-Low, Western Australia) and another one operating in the 350 MHz-15 GHz range (SKA-Mid, South Africa). I will describe the SKA's science drivers and give an update on the current construction activities and timeline to completion. I am eager to explore synergies with the proposed ARGOS instrument.

Speaker: Anna Bonaldi (SKAO)

11:00 RADIOBLOCKS and the VLBI technological road in Europe

RADIOBLOCKS is a 10 M€ Horizon Europe project that is developing building blocks for technological solutions to enable a broad range of new science and enhance European scientific competitiveness. RADIOBLOKS brings together the major European research infrastructures for radio astronomy and partners from industry and academia to develop the common blocks that European radio facilities will use to enable exciting scientific results.

Speaker: Giuseppe Cimo (Joint Institute for VLBI ERIC)

11:30 The European Processor Intiative

12:00 → 12:30 Space and Commercial Applications

12:00 Space science applications using ground based radio telescopes

Observations of human-made satellites using arrays of radio telescopes can provide the ultra-precise determination of their speed and position on the celestial sphere. The Planetary Radio Interferometry and Doppler Experiment (PRIDE) is a technique that connects ground-based radio astronomy and space science to deliver the sharpest view of spacecraft in our solar system. I will present the PRIDE's applications for a variety of scientific topics, from spacecraft orbit determination and space weather to planetary ephemerides and fundamental physics.

Speaker: Giuseppe Cimo (Joint Institute for VLBI ERIC)

12:30 → 13:30 Lunch

13:30 → 14:30 Fast Radio Bursts

13:30 ARGOS as part of a wide-field VLBI array

The science of radio astronomy is driven, to a large extent, by expanding the range of timescales, frequencies, field-of-view, and angular resolution we can achieve. Many serendipitous discoveries have been made by pushing the boundaries of what we can observe; pulsars and fast radio bursts (FRBs) are both seminal examples. So why not push to have it all? Here I will discuss the case for wide-field, long-baseline interferometry at the highest-possible time resolution. I will focus on what this can bring to the study of fast radio transients and I will discuss how ARGOS could potentially be part of a grander vision for a pan-European array that leverages the expertise and infrastructure that has been built up over the course of decades by the European Very-Long-Baseline Interferometry (VLBI) Network (EVN) and the Low-Frequency Array (LOFAR). I will pepper the talk with some examples from my AstroFlash group's own research on FRBs.

Speaker: Jason Hessels (University of Amsterdam & ASTRON)

14:00 Strongly lensed fast radio bursts with upcoming telescopes

The delay between multiple images of a strongly lensed fast radio burst (sl-FRB) can be used to measure cosmological parameters such as the Hubble constant and the Universe's shape with high precision, other than obtaining important information on the lens galaxy. However, detecting sl-FRBs is challenging because their fraction is low and decreases quickly at low redshifts. Moreover, it requires observing at least two images of an sl-FRB separated by O(10) days. We developed detailed simulations to estimate how many sl-FRBs could be detected by upcoming radio facilities with different observing strategies. In particular, we consider targeting known lensed galaxies, long-term observations of the North Celestial Pole, and following up on FRBs showing signs of microlensing in their signal. Our simulations account for important effects such as wave propagation in the lens galaxy and magnification of point sources distributed within the host galaxy. In this talk, I will review our results on the prospects of detecting and using sl-FRBs in the next few years, and how a new radio telescope such as ARGO could be a game-changer in the field.

Speaker: Daniele Michilli (MIT)

14:30 → 15:00 Prospects for 21cm intensity mapping with ARGOS

I briefly review the instrument specifications that would be necessary to support a 21cm intensity mapping science case with ARGOS. The upshot is that a dense core would be needed, either with lower frequency receivers on 6m dishes, or the proposed L-band receivers on 3m dishes. Control of systematics such as mutual coupling is paramount, and basic pointing capability would be desirable to increase the accessible survey area.

Speaker: Phil Bull (Jodrell Bank Centre for Astrophysics)

15:00 → 15:15 TBA

Speaker: Ezequiel Centofanti (CEA)

15:15 → 16:30 Summary and Open Discussion