The Sardinia Radio Telescope

Abstract

Context. The Sardinia Radio Telescope (SRT) is the new 64 m dish operated by the Italian National Institute for Astrophysics (INAF).Its active surface, comprised of 1008 separate aluminium panels supported by electromechanical actuators, will allow us to observe at frequencies of up to 116 GHz. At the moment, three receivers, one per focal position, have been installed and tested: a 7-beam K-band receiver, a mono-feed C-band receiver, and a coaxial dual-feed L/P band receiver. The SRT was officially opened in September 2013, upon completion of its technical commissioning phase. In this paper, we provide an overview of the main science drivers for the SRT, describe the main outcomes from the scientific commissioning of the telescope, and discuss a set of observations demonstrating the scientific capabilities of the SRT. Aims. The scientific commissioning phase, carried out in the 2012-2015 period, proceeded in stages following the implementation and/or fine-tuning of advanced subsystems such as the active surface, the derotator, new releases of the acquisition software, etc. One of the main objectives of scientific commissioning was the identification of deficiencies in the instrumentation and/or in the telescope subsystems for further optimization. As a result, the overall telescope performance has been significantly improved. Methods. As part of the scientific commissioning activities, different observing modes were tested and validated, and the first astronomical observations were carried out to demonstrate the science capabilities of the SRT. In addition, we developed astronomeroriented software tools to support future observers on site. In the following, we refer to the overall scientific commissioning and software development activities as astronomical validation. Results. The astronomical validation activities were prioritized based on technical readiness and scientific impact. The highest priority was to make the SRT available for joint observations as part of European networks. As a result, the SRT started to participate (in shared-risk mode) in European VLBI Network (EVN) and Large European Array for Pulsars (LEAP) observing sessions in early 2014. The validation of single-dish operations for the suite of SRT first light receivers and backends continued in the following year, and was concluded with the first call for shared-risk early-science observations issued at the end of 2015. As discussed in the paper, the SRT capabilities were tested (and optimized when possible) for several different observing modes: imaging, spectroscopy, pulsar timing, and transients.

Strong Evidence of Anomalous Microwave Emission from the Flux Density Spectrum of M31

“…The integrated flux densities from M31 presented in this Letter are part of the observations undertaken in 2016 during the Early Science Commissioning Phase of the INAF-Sardinia Radio Telescope (SRT) (Bolli et al 2015;Murgia et al 2016;Prandoni et al 2017). With its 64 m primary mirror, the SRT, at 6.7 GHz, has a beam primary lobe width at half maximum (FWHM) of ≃2 ′ .9.…”

Duty cycle of the radio galaxy B2 0258+35

“…To investigate the radio spectral properties of the extended lobes and to constrain any spectral curvature, we expand here the study at 1400 MHz presented by Shulevski et al (2012) to other frequencies. We have performed observations at 145, 350 and 6600 MHz using the Low-frequency Array (LOFAR, van Haarlem et al 2013), the Karl G. Jansky Very Large Array (VLA), and the Sardinia Radio Telescope (SRT, Bolli et al 2015;Prandoni et al 2017) respectively. Moreover, we have reprocessed archival observations of the Giant Metrewave Radio Telescope (GMRT; Swarup 1991) taken at 235 and 612 MHz.…”

The Galaxy in circular polarization: All-sky radio prediction, detection strategy, and the charge of the leptonic cosmic rays

“…For example, the Sardinia Radio Telescope has the capability to observe in the low portion of the electromagnetic spectrum: in P-band (305 − 410 MHz) and in L-band (1.3 − 1.8 GHz). By using the specifications given in [46], an observing time of 1 s per beam is required to reach the requested sensitivity in both frequency bands.…”