ESO VLT: MUSE reveals true story behind galactic crash

The MUSE instrument on ESO's Very Large Telescope has provided researchers with the best view yet of a spectacular cosmic crash. 

Observations reveal for the first time the motion of gas as it is ripped out of the galaxy ESO 137-001 as it ploughs at high speed into a vast galaxy cluster. 

The results are the key to the solution of a long-standing mystery, why star formation switches off in galaxy clusters. 

In this picture the colours show the motions of the gas filaments, red means the material is moving away from Earth compared to the galaxy and blue that it is approaching. 

Note that the upper-left and lower-right parts of this picture have been filled in using the Hubble image of this object. 

Credit: ESO/M. Fumagalli

A team of researchers led by Michele Fumagalli from the Extragalactic Astronomy Group and the Institute for Computational Cosmology at Durham University, were among the first to use ESO's Multi Unit Spectroscopic Explorer (MUSE) instrument on the VLT.

Observing ESO 137-001, a spiral galaxy 200 million light-years away in the southern constellation of Triangulum Australe (The Southern Triangle), they were able to get the best view so far of exactly what is happening to the galaxy as it hurtles into the Norma Cluster.

MUSE gives astronomers not just a picture, but provides a spectrum, or a band of colours, for each pixel in the frame.

With this instrument researchers collect about 90 000 spectra every time they look at an object, and thereby record a staggeringly detailed map of the motions and other properties of the observed objects.

ESO 137-001 is being robbed of its raw materials by a process called ram-pressure stripping, which happens when an object moves at high speed through a liquid or gas.

This is similar to how air blows a dog's hair back when it sticks its head out of the window of a moving car.

In this case the gas is part of the vast cloud of very thin hot gas that is enveloping the galaxy cluster into which ESO 137-001 is falling at several million kilometres per hour.

The galaxy is being stripped of most of its gas, the fuel needed to make the next generations of young blue stars.

ESO 137-001 is in the midst of this galactic makeover, and is being transformed from a blue gas-rich galaxy to a gas-poor red one. Scientists propose that the observed process will help to solve a long-standing scientific riddle.

"It is one of the major tasks of modern astronomy to find out how and why galaxies in clusters evolve from blue to red over a very short period of time," says Fumagalli.

"Catching a galaxy right when it switches from one to the other allows us to investigate how this happens."

Observing this cosmic spectacle, however, is no mean feat. The Norma Cluster lies close to the plane of our own galaxy, the Milky Way, so it is hidden behind copious amounts of galactic dust and gas.

With the help of MUSE, which is mounted on one of the VLT's 8-metre Unit Telescopes at the Paranal Observatory in Chile, scientists could not only detect the gas in and around the galaxy, but were able to see how it moves.

The new instrument is so efficient that a single hour of observing time was sufficient to obtain a high resolution image of the galaxy as well as the distribution and motion of its gas.

More information: Research paper (PDF): www.eso.org/public/archives/re… eso1437/eso1437a.pdf

ESO MUSE: Creates 3D Views of the Universe - Video

A new telescope tool for peering into the cosmos and creating three-dimensional views of the universe has passed its first major test at the ESO observatory in Chile's Atacama desert.

After a decade of design and development, the tool, called the Multi Unit Spectroscopic Explorer (MUSE), successfully captured its first images of deep space to create 3D views of the early universe.

Installed on the European Southern Observatory's Very Large Telescope (VLT) in Chile, MUSE can both study and image the depths of space.

"It has taken a lot of work by many people over many years," principle investigator Roland Bacon of the Lyon Astrophysics Research Center (CRAL) in France said in a statement.

"This seven-ton collection of optics, mechanics, and electronics is now a fantastic time machine for probing the early universe."

This colour composite of the unusual polar ring galaxy NGC 4650A was created from data from the MUSE instrument on ESO's Very Large Telescope in Chile.

The MUSE instrument, which went online in March 2014, splits the light from each part of the galaxy into component colors to show the chemical and physical properties of each point.

Credit: ESO/MUSE consortium/R. Bacon

MUSE uses 24 spectrographs to split light into its component colours (spectra) to assemble images and spectra of different regions of the sky.

Studies of these spectra can provide insight to astronomers about the composition and movements of various objects.

MUSE also creates a 3D image of objects from the light waves it receives. Known as Integral Field Spectroscopy (IFS), the technique allows astronomers to study the properties of different regions of an object at the same time.

Applying the technique to galaxies, for instance, can reveal not only their chemical composition but also details about their rotation.

DARPA MUSE: Deep program analysis and big data analytics create a public database

DARPA's MUSE seeks to leverage deep program analyses and big data analytics to create a public database containing mined inferences about salient properties, behaviours and vulnerabilities of software drawn from the hundreds of billions of lines of open source code available today.

The program aims to make significant advances in the way software is built, debugged, verified, maintained and understood, and to enable the automated repair of existing programs and synthesis of new ones.

During the past decade information technologies have driven the productivity gains essential to U.S. economic competitiveness, and computing systems now control significant elements of critical national infrastructure.

As a result, tremendous resources are devoted to ensuring that programs are correct, especially at scale.

Unfortunately, in spite of developers' best efforts, software errors are at the root of most execution errors and security vulnerabilities.

To help improve this state, DARPA has created the Mining and Understanding Software Enclaves (MUSE) program.

MUSE seeks to make significant advances in the way software is built, debugged, verified, maintained and understood.

The collective knowledge gleaned from MUSE's efforts would facilitate new mechanisms for dramatically improving software correctness, and help develop radically different approaches for automatically constructing and repairing complex software.

Suresh Jagannathan

"Our goal is to apply the principles of big data analytics to identify and understand deep commonalities among the constantly evolving corpus of software drawn from the hundreds of billions of lines of open source code available today," said Suresh Jagannathan, DARPA program manager.

"We're aiming to treat programs—more precisely, facts about programs—as data, discovering new relationships (enclaves) among this 'big code' to build better, more robust software."

Central to MUSE's approach is the creation of a community infrastructure that would incorporate a continuously operational specification-mining engine.

This engine would leverage deep program analyses and foundational ideas underlying big data analytics to populate and refine a database containing inferences about salient properties, behaviours and vulnerabilities of the program components in the corpus.

If successful, MUSE could provide numerous capabilities that have so far remained elusive.

"Ideally, we could enable a paradigm shift in the way we think about software construction and maintenance, replacing the existing costly and laborious test/debug/validate cycle with 'always on' program analysis, mining, inspection and discovery," Jagannathan said.

"We could see scalable automated mechanisms to identify and repair program errors, as well as tools to efficiently create new, custom programs from existing components based only a description of desired properties."

ESO MUSE: Powerful 3D spectrograph successfully installed on VLT

This view shows how the new MUSE instrument on ESO's Very Large Telescope gives a innovative three-dimensional depiction 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. 

Credit: ESO /MUSE consortium /R. Bacon/L. Calçada

Following testing and preliminary acceptance in Europe in September 2013, MUSE was shipped to ESO's Paranal Observatory in Chile.

It was reassembled at the base camp before being carefully transported to its new home at the VLT, where it is now installed on Unit Telescope 4.

MUSE is the latest of the second generation instruments for the VLT (the first two were X-shooter and KMOS and the next, SPHERE, will follow shortly).

The leader of the team and principal investigator for the instrument, Roland Bacon (Centre de Recherche Astrophysique de Lyon, France), expressed his feelings: "It has taken a lot of work by many people over many years, but we have done it!

It seems strange that this seven-tonne collection of optics, mechanics and electronics is now a fantastic time machine for probing the early Universe."

"We are very proud of the achievement—MUSE will remain a unique instrument for years to come."

MUSE instrument on its VLT Nasmyth platform

MUSE's science goals include delving into the early epochs of the Universe to probe the mechanisms of galaxy formation and studying both the motions of material in nearby galaxies and their chemical properties.

It will have many other applications, ranging all the way from studies of the planets and satellites in the Solar System, through the properties of star-forming regions in the Milky Way and out to the distant Universe.

As a unique and powerful tool for discovery MUSE uses 24 spectrographs to separate light into its component colours to create both images and spectra of selected regions of the sky.

It creates 3D views of the Universe with a spectrum for each pixel as the third dimension.

During the subsequent analysis the astronomer can move through the data and study different views of the object at different wavelengths, just like tuning a television to different channels at different frequencies.

MUSE instrument on its VLT Nasmyth platform

MUSE couples the discovery potential of an imaging device with the measuring capabilities of a spectrograph, while taking advantage of the much better image sharpness provided by adaptive optics.

The instrument is mounted on Unit Telescope 4 of the VLT, which is currently being converted into a fully adaptive telescope.

Since the start of 2014, Bacon and the rest of the MUSE integration and commissioning team at Paranal have recorded the MUSE story in a series of blog posts which can be followed here.

The team will present the first results from MUSE at the forthcoming 3D2014 workshop at ESO in Garching bei München, Germany.

"A muse is there to inspire. Indeed, MUSE has inspired us for many years and will continue to do so," says Bacon in a blog post on the first light.

"No doubt many astronomers from all over the world will also be charmed by our MUSE." Bacon reported.