MUSE is the greatest ground-based instrument ever built

MUSE. It looks like an espresso machine from hell, right?Credit: R. Bacon & the MUSE consortium — MUSE. It looks like an espresso machine from hell, right?
*Credit:* R. Bacon & the MUSE consortium

MUSE, the Multi Unit Spectroscopic Explorer, is my favorite instrument.

This steam-punk fever dream barely fits on the Nasmyth B platform of Yepun, (UT4 on ESO's Very Large Telescope).

I was involved in commissioning and science verification of the instrument, so I'm not totally unbiased. But the data are absolutely stunning, and I think you'll agree.

MUSE mounted on the Nasmyth Platform of the Very Large Telescope's Unit Telescope 4.

This view shows how the new MUSE instrument on ESO's Very Large Telescope gives a three-dimensional view of a distant galaxy. For each part of the galaxy the light has been split up into its component colours - revealing not only the motions of different parts of the galaxy but also clues to its chemical composition and other properties.

For my non-astronomer friends, all you need to know is that MUSE is a special type of instrument called an Integral Field Unit (IFU) spectrograph.

It effectively takes an image of the sky, but every pixel in that image is also a spectrum. It's three dimensional data (recording two of space and one of wavelength), enabling one to map the kinematics of stars and gas in a galaxy, obtain spatially resolved spectral diagnostic maps, etc.

For my astronomer friends, you need only know two things:

It is the highest throughput spectrograph on the mountain, beating even our slit spectrographs like UVES and X-shooter. That's ... astonishing.
It has a one-by-one arcminute field of view with subarcsecond spatial resolution (initially seeing- limited).

Here's how MUSE works, by the way.

I want to quickly show off one of the early science verification observations we obtained. In what would have taken more than fifty pointings with, e.g., GMOS on Gemini, we mapped the northern filaments in Centaurus A in about fifteen minutes with only two pointings.

Here's what we found.

The Multi-Unit Spectroscopic Explorer (MUSE) is the stunning new Integral Field Unit (IFU) spectrograph on ESO's Very Large Telescope (VLT). Along with very high throughput, it boasts an (unheard of) 1'x1' field of view. During the Science Verification Phase of the instrument, we observed the northern filaments in Cen A.

H-alpha + [N II] velocity structure in the northern filaments of Centaurus A. The image is about 2 kpc on a side. Even with the seeing limit (~0.8''), we achieve a physical resolution of about 40 pc.

Gorgeous, right?

These data are published in Santoro et al. (2015) and Hamer et al. (2015).

Also, friends in the US: YES. You can propose for MUSE, and VLT time in general. There's a huge misconception that ESO time requires a European PI, and it's simply not true. A proposal consisting of mostly US investigators isn't even necessarily less competitive on the TAC, outside of rare edge-cases. So, propose for MUSE (and/but: good luck with that ten-to-one oversubscription. ;)

The MUSE story goes back more than a decade. Hear about it below, from MUSE PI Roland Bacon (U. Lyon).

The 35-minute documentary explores the inspiration and the story behind MUSE, the Multi Unit Spectroscopic Explorer installed at ESO's Very Large Telescope. The film was produced by CNRS Images, in partnership with ESO. The film project was led by Roland Bacon, Principal Investigator of the MUSE project, and directed by Christophe Gombert and Claude Delhaye.