It has been about 3 months since the first blue camera cryostat was shipped to France. In this post, we are showing the updates on development of the Spectrograph systems. At Laboratorie d’Astorophysique de Marseille (LAM), we finished the performance test using only a red camera unit, and started fully integrating the first spectrograph module (called SM1). We have already… Read more »
One of the PFS instrument “Metrology Camera” was finally shipped from Taiwan to Hawaii!! Metrology Camera is an instrument used to measure the fibers position while we configure fibers to target objects. Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan has the responsibility for Metrology Camera development, and they tested its performances before shipping in the last a… Read more »
Written by Masayuki Tanaka (NAOJ) PFS survey is going to collect a huge amount of data. Thanks to the high multiplexity with 2400 fibers, we are going to collect as many as 67,000 spectra in a single night according to the current survey plan. In addition, we will measure a variety of physical parameters — redshifts of galaxies, strengths of emission and absorption… Read more »
“Metrology Camera System” is one of the PFS instrument subsystems under development by ASIAA (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan). This is a small telescope system installed onto the Cassegrain Focus at the bottom of the Subaru telescope to look up the Prime focus, take the image of approximately 2400 back-illuminated fiber spots in one exposure with the large… Read more »
In January 2018, the visible-blue camera cryostat of the first spectrograph module was shipped from Johns Hopkins University (JHU, the United States of America) to Laboratoire d’Astrophysique de Marseille (LAM, France). Visible-blue camera at Johns Hopkins University PFS are developing the four identical spectrograph modules, each of which has three channels with visible-blue, visible-red and near-infrared camera units, in order to… Read more »
At California Institute of Technology (Caltech, USA), the fiber positioners “Cobra” are assembled into a module (so-called “Cobra module”) by the teams from Caltech, NASA Jet Propulsion Laboratory (JPL) and Brazil in collaboration. As highlighted in the previous article, the first Cobra module has been assembled, tested and calibrated, so will be shipped soon to Taiwan, where the Cobra modules will… Read more »
From 27 November to 1 December 2017 was held the 9th PFS collaboration meeting at Kavli IPMU, the University of Tokyo, in Kashiwa city, Japan. More and more participants have joined to the meeting, and this year about 130 collaborators gathered to the meeting. On 28 and 29 November, we had the joint sessions and shared the project updates. The… Read more »
At the laboratory of California Institute of Technology (Caltech), USA, the fiber positioner modules are being assembled by Caltech, NASA Jet Propulsion Laboratory (USA), and Laboratorio Nacional de Astrofisica (Brazil). PFS will develop 42 fiber modules for the observation, and the spare modules. We have been assembling the first module, testing it to control the 57 actuators “Cobra” in the… Read more »
The subsystems of the PFS instrument are being developed at various institutes. These subsystems will be delivered to the Subaru telescope in Hawaii from what will be finished integration and test at the laboratory. It is already one year before the first subsystem will be delivered to the Subaru telescope, and start its integration and test there. To operate the… Read more »
Written by Naoki Yasuda (Kavli IPMU) The galaxies PFS will observe are more than 8 billion light years away and their brightness is less than one to a 10 million of the stars visible to naked eyes. To measure the properties of these faint galaxies accurately, we have to develop data analysis software which can deal with various kinds of noises included in the acquired… 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。
