A few month ago, we reported that we had entered on the second phase of the fiber cable integration (see this). This time we are going to show news since then. PFS catches the light of stars and galaxies by fibers installed on the prime focal plane at the top of Subaru Telescope, and obtains their spectra with the spectrograph… Read more »
The annual PFS collaboration meeting was held from 9 to 13 December 2019 at California Institute of Technology (Caltech). Here is a brief report by a young researcher who participated in the meeting. The collaboration meeting is a good opportunity for us to exchange scientific ideas. It is important to learn the status of instrumentation and scientific goals/objectives from other… Read more »
Earlier we reported that one of the PFS instruments, the first Spectrograph Module was shipped to Hawaii Observatory, National Astronomical Observatory of Japan in Hawaii (see here). More recently, the module has been transported to Subaru Telescope at the summit of Maunakea, and re-assembled there. PFS Spectrograph Module consists of ten and several assemblies such as camera units, grating assemblies,… Read more »
PFS Science Meeting was held at Columbia University in New York, USA from October 4 to 7, 2019. PFS Science Team conducts a meeting in which we intensively discuss what kind of observations should be made in the large survey observation using PFS about once a year (see our post for the last year’s meeting). In this meeting, technical topics… Read more »
In October 2019, one of the PFS instrument subsystems, the first Spectrograph Module was shipped to Hawaii Observatory, National Astronomical Observatory of Japan. We obtain about 2400 spectra with four Spectrograph Modules. The Spectrograph Modules are being developed by Laboratoire d’Astrophysique de Marseille (LAM, France), Johns Hopkins University (the USA), Princeton University (the USA) and Laboratório Nacional de Astrofísica (Brazil). Since… Read more »
Last year Metrology Camera System (MCS) was shipped to Subaru Telescope of National Astronomical Observatory of Japan, in Hawaii. After onsite integration and test, we installed MCS to the telescope and carried out optical alignment and on-telescope performance tests in June and October 2018. (See this for details) MCS is installed to the Cassegrain focus at the bottom of the… Read more »
PFS instrument delivers lights of stars and galaxies from the telescope to our spectrographs by a ~60m-long cable of optical fibers. As we presented in the previous post (https://pfs.ipmu.jp/blog/2017/04/p447), the fiber cables were assembled at the factory of PPC Broadband Inc. in UK. Then the cables were shipped to LNA in Brazil for the next step. If some stress such… Read more »
Our collaborator Prof. James Gunn awarded Kyoto Prize of Basic Science. congratulations! https://www.kyotoprize.org/en/laureates/james_gunn/
Among the PFS instruments, “Cobra” modules position fibers to galaxies and stars on the Subaru Prime Focal plane. 42 Cobra modules, each of which consists of 57 fibers and its positioners, cover the entire PFS field of view without any inaccessible gaps as shown in Figure 1. Two groups are collaborating to assemble “Cobra Modules”; Brazilian team responsible for fibers,… Read more »
From 10th to 14th December 2018, we held 10th PFS collaboration meeting at Shanghai Jiao Tong University, China. Usually, individual groups for developing instruments and designing observational survey have discussions via regular video/phone meetings and sometimes by visiting each other. This meeting, on the other hand, is the biggest for the whole collaboration to gather up for discussions. About 80… Read more »
We will observe ~2400 objects using four identical spectrograph modules, each of which acquires ~600 spectra of astronomical sources and calibration sources. Each module covers wide wavelength range on visible and near-infrared band (380 — 1260 nm). To achieve this, the module has 3 camera units; visible-blue, visible-red and near-infrared. The light of each band is introduced by using two “dichiroic mirrors”, which split the light at a given wavelength.
PFSでは約2400個の天体を観測しますが、4つの同型の分光器を用いてそれぞれ600本のスペクトルを取得します。各分光器は可視光域から近赤外域までの広い波長範囲 (380 から1260 nm) をカバーする為、「可視光域青用」、「可視光域赤用」、「近赤外域用」の3つのカメラユニットを持っています。3つのカメラには、特定の波長で光を分けることのできるダイクロイックミラーを2つ用いて、光を導入します。
To measure the fibers position on the focal plane, “Metrology Camera System” is attached on the Cassegrain focus of Subaru telescope. Looking up to the prime focus (see this image from HSC blog for clear image), this camera takes a image of back-illuminated fibers. Thanks to a large format of ~50 M pixels CMOS sensor, this camera can acquire all ~2400 fiber spots in a single exposure. The camera system is also designed to execute the process from exposure to measurement of fiber centroids within 5 seconds. Effective measurement of the fibers position enables us to shorten overhead for fiber configuration and execute large statistical survey observation.
The Metrology Camera System will be delivered to Subaru in early 2018.
焦点面上のファイバーの位置を測定する為に、『メトロロジカメラシステム』をすばる望遠鏡のカセグレン焦点に取り付けます。このカメラは焦点面を見上げるようにして後ろ側から照らされたファイバーの画像を取得します(イメージ的にはこちらの画像 (HSCブログより) のような感じです)。メトロロジカメラには50Mピクセルの大判のCMOSセンサが搭載されているため、約2400本のファイバー像をたった一回の露出で得ることができます。また、画像の取得から各ファイバーの位置測定までを5秒以内に行うように設計されています。このようにファイバーの効率よく位置を測定することで、ファイバーの配置など観測準備にかかる時間をなるべく短くし、大規模サーベイ観測を行うことができるのです。
メトロロジカメラシステムは2018年4月にすばる望遠鏡へ搬送されるました。
The Spectrograph Clean Room is a room whose size is 6.7 m wide, 8.6 m long ,and 3.6 m high. Four PFS spectrographs will be accommodated in the clean room. To stabilize the spectrograph performance, the temperature in the room will be controlled at 5 +- 1 degree Celsius. Besides, a crane with capability of 500 kg is installed for assembly and maintenance of the Spectrograph.
分光器設置室は、すばる望遠鏡ドーム棟4階に建設された部屋で、幅6.7m × 奥行8.6m × 高さ 3.6 mの大きさです。 PFSの4台の分光器がこの部屋に設置されます。分光器の安定性を図るために、部屋全体が5±1℃の範囲で温度管理されます。また、分光器の設置やメンテナンス用に室内には耐荷重500kgのクレーンが設置されています。
