The instrumentation of the Prime Focus Spectrograph (PFS), a next generation facility instrument on the Subaru telescope, is now in the final phase of its commissioning process and its general, open-use operations for sciences will provisionally start in 2025. The instrument enables simultaneous spectroscopy with 2386 individual fibers distributed over a very wide (∼1.3 degrees in diameter) field of view on the Subaru’s prime focus. The spectra cover a wide range of wavelengths from 380nm to 1260nm in one exposure in the Low-Resolution (LR) mode (while the visible red channel has the Medium-Resolution (MR) mode as well that covers 710−885nm). The system integration activities at the observatory on Maunakea in Hawaii have been continuing since the arrival of the Metrology Camera System in 2018. On-sky engineering tests and observations have also been carried out continually since September 2021 and, despite various difficulties in interlacing commissioning processes with development activities on the schedule and addressing some major issues on hardware and software, the team successfully observed many targeted stars as intended over the entire field of view (Engineering First Light) in September 2022. Then in parallel to the arrival, integration and commissioning of more hardware components, validations and optimizations of the performance and operation of the instrument are ongoing. The accuracy of the fiber positioning process and the speed of the fiber reconfiguration process have been recently confirmed to be ∼ 20−30μm for 95% of allocated fibers, and ∼130 seconds, respectively. While precise quantitative analyses are still in progress, the measured throughput has been confirmed to be consistent with the model where the information from various sub-components and sub-assemblies is integrated. Long integration of relatively faint objects are being taken to validate an expected increase of signal-to-noise ratio as more exposures are taken and co-added without any serious systematic errors from, e.g., sky subtraction process. The PFS science operation will be carried out in a queue mode by default and various developments, implementations and validations have been underway accordingly in parallel to the instrument commissioning activities. Meetings and sessions are arranged continually with the communities of potential PFS users on multiple scales, and discussions are iterated for mutual understanding and possible optimization of the rules and procedures over a wide range of processes such as proposal submission, observation planning, data acquisition and data delivery. The end-to-end processes of queue observations including successive exposures with updated plans based on assessed qualities of the data from past observations are being tested during engineering observations, and further optimizations are being undertaken. In this contribution, a top-level summary of these achievements and ongoing progresses and future perspectives will be provided.
PFS (Prime Focus Spectrograph), a next generation facility instrument on the Subaru telescope, is now being tested on the telescope. The instrument is equipped with very wide (1.3 degrees in diameter) field of view on the Subaru’s prime focus, high multiplexity by 2394 reconfigurable fibers, and wide waveband spectrograph that covers from 380nm to 1260nm simultaneously in one exposure. Currently engineering observations are ongoing with Prime Focus Instrument (PFI), Metrology Camera System (MCS), the first spectrpgraph module (SM1) with visible cameras and the first fiber cable providing optical link between PFI and SM1. Among the rest of the hardware, the second fiber cable has been already installed on the telescope and in the dome building since April 2022, and the two others were also delivered in June 2022. The integration and test of next SMs including near-infrared cameras are ongoing for timely deliveries. The progress in the software development is also worth noting. The instrument control software delivered with the subsystems is being well integrated with its system-level layer, the telescope system, observation planning software and associated databases. The data reduction pipelines are also rapidly progressing especially since sky spectra started being taken in early 2021 using Subaru Nigh Sky Spectrograph (SuNSS), and more recently using PFI during the engineering observations. In parallel to these instrumentation activities, the PFS science team in the collaboration is timely formulating a plan of large-sky survey observation to be proposed and conducted as a Subaru Strategic Program (SSP) from 2024. In this article, we report these recent progresses, ongoing developments and future perspectives of the PFS instrumentation.
PFS (Prime Focus Spectrograph), a next generation facility instrument on the Subaru telescope, is a very wide- field, massively multiplexed, and optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed in the 1.3 degree-diameter field of view. The spectrograph system has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously deliver spectra from 380nm to 1260nm in one exposure. The instrumentation has been conducted by the international collaboration managed by the project office hosted by Kavli IPMU. The team is actively integrating and testing the hardware and software of the subsystems some of which such as Metrology Camera System, the first Spectrograph Module, and the first on-telescope fiber cable have been delivered to the Subaru telescope observatory at the summit of Maunakea since 2018. The development is progressing in order to start on-sky engineering observation in 2021, and science operation in 2023. In parallel, the collaboration is trying to timely develop a plan of large-sky survey observation to be proposed and conducted in the framework of Subaru Strategic Program (SSP). This article gives an overview of the recent progress, current status and future perspectives of the instrumentation and scientific operation.
The AO188 Single Conjugate facility AO system at Subaru Telescope delivers diffraction-limited images in near-IR in natural and laser guide star modes. We have recently started a major upgrade of AO188 to fulfill the high performance requirements of its downstream instruments, including the Subaru Coronagraphic Extreme-AO. The first phase of this upgrade started in 2017 with the integration of a new real time computer (RTC) and real time system (RTS) CACAO(https://github.com/CACAO-org/CACAO), an open-source real-time software for adaptive optics developed collaboratively and used extensively by the SCExAO instrument. This major upgrade will enable loop optimization, predictive control and include diagnosis tools, therefore improving the performance and stability of AO188 and its downstream instrument module. This paper introduces the architecture of the new RTS describing the different steps we followed to adapt CACAO to our AO interfaces and aging hardware, in preparation of our first engineering tests on-sky achieved successfully on July 23rd 2018.
Subaru Telescope, an 8-meter class optical telescope located in Hawaii, has been using a high-availability commodity cluster as a platform for our Observation Control System (OCS). Until recently, we have followed a tried-and-tested practice of running the system under a native (Linux) OS installation with dedicated attached RAID systems and following a strict cluster deployment model to facilitate failover handling of hardware problems,1.2 Following the apparent benefits of virtualizing (i.e. running in Virtual Machines (VMs)) many of the non- observation critical systems at the base facility, we recently began to explore the idea of migrating other parts of the observatory's computing infrastructure to virtualized systems, including the summit OCS, data analysis systems and even the front ends of various Instrument Control Systems. In this paper we describe our experience with the initial migration of the Observation Control System to virtual machines running on the cluster and using a new generation tool – ansible - to automate installation and deployment. This change has significant impacts for ease of cluster maintenance, upgrades, snapshots/backups, risk-management, availability, performance, cost-savings and energy use. In this paper we discuss some of the trade-offs involved in this virtualization and some of the impacts for the above-mentioned areas, as well as the specific techniques we are using to accomplish the changeover, simplify installation and reduce management complexity.
KEYWORDS: Stars, Computing systems, Observatories, Control systems, Telescopes, Data archive systems, Switches, Internet, Data analysis, Solid state lighting
Subaru Telescope has recently replaced most equipment of Subaru Telescope Network II with the new equipment which
includes 124TB of RAID system for data archive. Switching the data storage from tape to RAID enables users to access
the data faster. The STN-III dropped some important components of STN-II, such as supercomputers, development &
testing subsystem for Subaru Observation Control System, or data processing subsystem. On the other hand, we invested
more computers to the remote operation system. Thanks to IT innovations, our LAN as well as the network between Hilo
and summit were upgraded to gigabit network at the similar or even reduced cost from the previous system. As the result
of the redesigning of the computer system by more focusing on the observatory operation, we greatly reduced the total
cost for computer rental, purchase and maintenance.
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