From 14 December, Monday to 18 December, Friday, we held the 7th PFS collaboration meeting at Laboratoire d’Astrophysique de Marseille (LAM) in France. This annual meeting, where the collaborators in the world put together, is one of the great opportunity to discuss the project face to face. During the meeting, technical teams and science teams report their progress at the… Read more »
The metrology camera system (MCS) is one of the PFS subsystems that has been developed by ASIAA (Academia Sinica Institute of Astronomy and Astrophysics) in Taiwan. MCS will be the key component for quick fiber configuration. It is a camera system mounted at the Cassegrain port of the Subaru Telescope looking up the prime focus where the ~2400 science fibers and ~100 fiducial fibers… Read more »
A review meeting for the Clean Room holding the spectrographs was held on 19 and 20 August at Hawaii Observatory, National Astronomical Observatory of Japan. The participants were from Kavli IPMU, collaborators having the responsibility for the Spectrograph, and Hawaii Observatory. The spectrographs are put on the fourth floor in the dome building of Subaru telescope. The floor will have a huge clean… Read more »
From third to fourteenth August, International Astronomical Union (IAU) general assembly was held in Honolulu, Hawaii, the US. Astronomers from all over the world gathered for discussions during this international workshop. The PFS project presented a poster, with which the project manager and collaborators introduced the project and explained the progress.
Subaru/PFS science workshop for Japanese researchers was held at NAOJ Mitaka campus on July 7-11, 2015. About 90 Japanese researchers gathered and discussed possible science cases with the PFS. In this workshop, not only three PFS key sciences (“cosmological” studies to understand the nature of dark matter and dark energy, “galactic archaeology” studies to reveal the history of our Milky… 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。
