First light is an exciting time for astronomers and engineers who help bring new telescopes up to speed. One of the most recent and important first light milestones recently occurred at the Subaru Telescope in Hawaii. Although it has been in operation since 2005, the main telescope at the National Astronomical Observatory of Japan (NAOJ) recently received an upgrade that allows it to observe 2,400 astronomical objects at once over a patch of sky the size of several moons.
Those 2,400 objects will be observed by the Prime Focus Spectrograph (PFS), which itself has multiple sub-components and was developed by a dozen universities and companies on four continents. The main components consist of a “Prime Focus Instrument”, which contains 2400 individual fibers and allows it to focus on different parts of the sky. Data from those fibers is then fed into a Spectrograph System (SpS), which analyzes it to produce the data used in scientific papers.
The SpS consists of four separate spectrographs, covering spectra from ultraviolet to near-infrared, far more than the human eye can capture alone. Or, as a press release from NAOJ puts it more poetically, it covers “one and a half rainbows”.
Unfortunately, these sensitive instruments are not usually used to capture rainbows, but in theory the Wide Field Corrector could. It’s a seven-lens optical system developed specifically for this upgrade that allows Subaru’s operators to correct errors in image collection before they become a problem.
There are also some support systems to facilitate the actual data collection. In addition to the SpS, the PFS uses a giant 8960 x 5778 pixel CMOS camera known as the Metrology Camera System to track exactly where the fibers that collect the data are located. If one is out of place, it can throw off the data the system collects.
All of these upgrades come with high expectations – the goal of the PFS upgrade is literally to understand where the universe came from and where it’s going. It will coordinate with the Hyper Suprime-Cam already installed in an effort to “reveal the nature of dark matter and dark energy, structure formation in the universe, and the physical processes of galaxy formation and evolution.
That’s a lot for one telescope upgrade, but there will certainly be a lot of data to analyze. Perhaps the team could implement an eyepiece to attach to the PFS before it begins collecting data, as it did when the telescope was first commissioned in 2005. Possibly the team working so hard on it worked, even can see rainbows.
NAOJ – 2400 new eyes on the sky to see cosmic rainbows
Prime Focus Spectrograph
UT– Astronomers set a new record and find the farthest galaxy. Its light took 13.4 billion years to reach us
UT– Subaru telescope sees 1800 supernovae
Image of the PFS mounted on the telescope.
Credit – Kavli IPMU