Insane Spectograhy on AAO.

[Bassnut]

Insane fiber optic machine on the AAO at Siding spring.
This is just nuts, Spectography on 400 odd objects at the same time, an Ozzy invention.
This CNC machine (mounted right on the back of the imaging plate) auto places 400 odd mini magnetic block fiber optic lenses (to 10 micron accuraccy) where stars/galaxys are from a sky map on a metal plate , the fibers go 30 odd meters to a room with 400 diffraction screens, each in a straight line split onto 3 different cameras to image 400 objects at once at multiple frequencies. When the machine is finished placeing, the plate is flipped 180deg to the focal point and imaging starts. At the same time, another plate on the back is worked on by the CNC machine ready for the next image. Engineering wise, this is just draw dropping, insane to watch in action. I went to the Siding spring open day on the weekend, where this was all on display.

[DJT]

mad indeed. I was reading the Mt Stromolo book the other week where they talked of kit being developed in Siding Springs for a number of missions/observatories. At the same time, I was also reading the starlight detectives which has a fascinating section on the early days of spectography.

What you describe is pretty cool indeed. Don't know much about CNC but it sounds like whats happening is that the machine is "cutting" required slits based on next target/skymap pre capture?

[mithrandir]

Going to the ASNSW meeting on Friday Fred? Kyler Kuehn, AAO will be talking about the new Starbug technology and TAIPAN.

[sheeny]

Very cool. I've known about this for a while, but it'd be great to see. I didn't realise the open day was on. It'd make a good long weekend trip away.

Al.

[sheeny]

No, it's not cutting anything, just placing the magnetic heads of the fibre optics very precisely.;)

Al.

[gary]

Hi Fred,

The 2df (two degree field) fiber positioner first began operations
in 1997.

What has just recently come online is the new High Efficiency
and Resolution Multi-Element Spectrograph (HERMES) which works
in conjunction with 2df.

Both the 2df and HERMES were engineered and built at the AAO offices
here in Sydney.

HERMES can provide simultaneous observations in the following bands -
Blue: 471.8 - 490.3 nm
Green: 564.9 - 587.3 nm
Red: 648.1 - 673.9 nm
IR: 759.0 - 789.0 nm

The CCD detectors are 4096 x 4112 and operate at 170K.

It is arguably the most sophisticated spectrograph ever built for a telescope.

The primary science project HERMES is being employed on is the GALactic
Archeology with HERMES (GALAH) survey. When used in conjunction with the
existing AAT two-degree field (2dF) optical fibre positioner, HERMES
provides simultaneous spectra for 400 objects in four bands.

GALAH will obtain precise radial velocities and abundances of over 15 different
chemical elements per star for over a million stars.

The resulting data sets will hopefully yield a detailed view of the formation and
evolution of the Galaxy.

You can read more about GALAH here :-
https://twitter.com/galahsurvey

[DavidTrap]

I thought this had been around for a while. Pretty impressive technology.

Might have to get to one of these open days at Siding Springs - are they annual events or every 5-10yrs??

DT

[Steffen]

At a recent WSAAG meeting Fred Watson talked about the technology, and also about the newer robotic/vacuum-attached heads that march into place independently and simultaneously. Fascinating stuff.

Cheers
Steffen.

[g__day]

Engineers can be pretty clever folk! Imagine the amount of data those thing produce that one has to process - that too would be pretty fantastic!

[Bassnut]

Now THAT is much madder, geez.

[Bassnut]

Thanks Gary. I was told all this but went into data overload whilst watching
the machine. A bit of clicking on your link found a manual (https://www.aao.gov.au/files/2dF-HERMES-obs-manual.pdf) for the 2DF. Thats great that they post this publicly, excellent read (for an engineer :P).

[Bassnut]

Oh, and the yellow "guide" fiber locations, are a bunch of 7 ultra fine fibers together on one block (found out after asking how you can guide on just one blob that is there or not ;-).

A sneaky little supprise was, the AAO guide log I had a bit of a squiz at, showed 4 arc sec error on RA, whoa, not too flash I might have mentioned :whistle:. This is not a problem for spectography I was assured, makes sense, thats OK then, but............ mmmm, wonder what it was like when David Marlin was active on it?.