Showing posts with label Multi Unit Spectroscopic Explorer (MUSE). Show all posts
Showing posts with label Multi Unit Spectroscopic Explorer (MUSE). Show all posts

Thursday, February 07, 2019

Bubbles of Brand New Stars

PR Image eso1903a
Bubbles of Brand New Stars 
 
Jumbo Jets 
 
Digitized Sky Survey image around the HII region LHA 120-N 180B 
 
The HII region LHA 120-N 180B in the constellation Mensa
 
Jet Infographic



Videos

ESOcast 193 Light: Bubbles of Brand New Stars
PR Video eso1903a
ESOcast 193 Light: Bubbles of Brand New Stars 

Zooming in on the HII Region LHA 120-N 180B
Zooming in on the HII Region LHA 120-N 180B

Panning across N180
Panning across N180



This dazzling region of newly-forming stars in the Large Magellanic Cloud (LMC) was captured by the Multi Unit Spectroscopic Explorer instrument (MUSE) on ESO’s Very Large Telescope. The relatively small amount of dust in the LMC and MUSE’s acute vision allowed intricate details of the region to be picked out in visible light.

This region of the Large Magellanic Cloud (LMC) glows in striking colours in this image captured by the Multi Unit Spectroscopic Explorer (MUSE) instrument on ESO’s Very Large Telescope (VLT). The region, known as LHA 120-N 180B — N180 B for short — is a type of nebula known as an H II region (pronounced “H two”), and is a fertile source of new stars.

The LMC is a satellite galaxy of the Milky Way, visible mainly from the Southern Hemisphere. At only around 160 000 light-years away from the Earth, it is practically on our doorstep. As well as being close to home, the LMC’s single spiral arm appears nearly face-on, allowing us to inspect regions such as N180 B with ease.

H II regions are interstellar clouds of ionised hydrogen — the bare nuclei of hydrogen atoms. These regions are stellar nurseries — and the newly formed massive stars are responsible for the ionisation of the surrounding gas, which makes for a spectacular sight. N180 B’s distinctive shape is made up of a gargantuan bubble of ionised hydrogen surrounded by four smaller bubbles.

Deep within this glowing cloud, MUSE has spotted a jet emitted by a fledgling star — a massive young stellar object with a mass 12 times greater than our Sun. The jet — named Herbig–Haro 1177, or HH 1177 for short — is shown in detail in this accompanying image. This is the first time such a jet has been observed in visible light outside the Milky Way, as they are usually obscured by their dusty surroundings. However, the relatively dust-free environment of the LMC allows HH 1177 to be observed at visible wavelengths. At nearly 33 light-years in length, it is one of the longest such jets ever observed.

HH 1177 tells us about the early lives of stars. The beam is highly collimated; it barely spreads out as it travels. Jets like this are associated with the accretion discs of their star, and can shed light on how fledgling stars gather matter. Astronomers have found that both high- and low-mass stars launch collimated jets like HH 1177 via similar mechanisms — hinting that massive stars can form in the same way as their low-mass counterparts.

MUSE has recently been vastly improved by the addition of the Adaptive Optics Facility , the Wide Field Mode of which saw first light in 2017. Adaptive optics is the process by which ESO’s telescopes compensate for the blurring effects of the atmosphere — turning twinkling stars into sharp, high-resolution images. Since obtaining these data, the addition of the Narrow Field Mode, has given MUSE vision nearly as sharp as that of the NASA/ESA Hubble Space Telescope — giving it the potential to explore the Universe in greater detail than ever before.



More Information

This research was presented in a paper entitled “An optical parsec-scale jet from a massive young star in the Large Magellanic Cloud” which appeared in the journal Nature.

The research team was composed of A. F. McLeod (who conducted this research while at the University of Canterbury, New Zealand and is now affiliated with the Department of Astronomy, University of California, Berkeley, and the Department of Physics and Astronomy, Texas Tech University, USA), M. Reiter (Department of Astronomy, University of Michigan, Ann Arbor, USA), R. Kuiper (Institute of Astronomy and Astrophysics, University of Tübingen, Germany), P. D. Klaassen (UK Astronomy Technology Centre, Royal Observatory Edinburgh, UK) and C. J, Evans (UK Astronomy Technology Centre, Royal Observatory Edinburgh, UK).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 16 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a Strategic Partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”



Links



Contacts 

Anna McLeod
Postdoctoral Research Fellow — Texas Tech University & University of California Berkeley
Tel: +1 80 6834 2588

Calum Turner
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6670
Email: pio@eso.org


Source: ESO/News


Tuesday, October 02, 2018

A Universe Aglow

Digitized Sky Survey image around the Hubble ultra Deep Field

The Hubble Ultra Deep Field in the constellation of Fornax



Videos

ESOcast 178 Light: A Universe Aglow (4K UHD)
ESOcast 178 Light: A Universe Aglow (4K UHD)



MUSE spectrograph reveals that nearly the entire sky in the early Universe is glowing with Lyman-alpha emission

Deep observations made with the MUSE spectrograph on ESO’s Very Large Telescope have uncovered vast cosmic reservoirs of atomic hydrogen surrounding distant galaxies. The exquisite sensitivity of MUSE allowed for direct observations of dim clouds of hydrogen glowing with Lyman-alpha emission in the early Universe — revealing that almost the whole night sky is invisibly aglow.

An unexpected abundance of Lyman-alpha emission in the Hubble Ultra Deep Field (HUDF) region was discovered by an international team of astronomers using the MUSE instrument on ESO’s Very Large Telescope (VLT). The discovered emission covers nearly the entire field of view — leading the team to extrapolate that almost all of the sky is invisibly glowing with Lyman-alpha emission from the early Universe [1].

Astronomers have long been accustomed to the sky looking wildly different at different wavelengths, but the extent of the observed Lyman-alpha emission was still surprising. “Realising that the whole sky glows in optical when observing the Lyman-alpha emission from distant clouds of hydrogen was a literally eye-opening surprise,” explained Kasper Borello Schmidt, a member of the team of astronomers behind this result.

This is a great discovery!” added team member Themiya Nanayakkara. “Next time you look at the moonless night sky and see the stars, imagine the unseen glow of hydrogen: the first building block of the universe, illuminating the whole night sky.”

The HUDF region the team observed is an otherwise unremarkable area in the constellation of Fornax (the Furnace), which was famously mapped by the NASA/ESA Hubble Space Telescope in 2004, when Hubble spent more than 270 hours of precious observing time looking deeper than ever before into this region of space.

The HUDF observations revealed thousands of galaxies scattered across what appeared to be a dark patch of sky, giving us a humbling view of the scale of the Universe. Now, the outstanding capabilities of MUSE have allowed us to peer even deeper. The detection of Lyman-alpha emission in the HUDF is the first time astronomers have been able to see this faint emission from the gaseous envelopes of the earliest galaxies. This composite image shows the Lyman-alpha radiation in blue superimposed on the iconic HUDF image.

MUSE, the instrument behind these latest observations, is a state-of-the-art integral field spectrograph installed on Unit Telescope 4 of the VLT at ESO’s Paranal Observatory [2]. When MUSE observes the sky, it sees the distribution of wavelengths in the light striking every pixel in its detector. Looking at the full spectrum of light from astronomical objects provides us with deep insights into the astrophysical processes occurring in the Universe [3].

"With these MUSE observations, we get a completely new view on the diffuse gas 'cocoons' that surround galaxies in the early Universe," commented Philipp Richter, another member of the team.
The international team of astronomers who made these observations have tentatively identified what is causing these distant clouds of hydrogen to emit Lyman-alpha, but the precise cause remains a mystery. However, as this faint omnipresent glow is thought to be ubiquitous in the night sky, future research is expected to shed light on its origin.

In the future, we plan to make even more sensitive measurements,” concluded Lutz Wisotzki, leader of the team. “We want to find out the details of how these vast cosmic reservoirs of atomic hydrogen are distributed in space.



Notes


[1] Light travels astonishingly quickly, but at a finite speed, meaning that the light reaching Earth from extremely distant galaxies took a long time to travel, giving us a window to the past, when the Universe was much younger.

[2] Unit Telescope 4 of the VLT, Yepun, hosts a suite of exceptional scientific instruments and technologically advanced systems, including the Adaptive Optics Facility, which was recently awarded the 2018 Paul F. Forman Team Engineering Excellence Award by the American Optical Society.

[3] The Lyman-alpha radiation that MUSE observed originates from atomic electron transitions in hydrogen atoms which radiate light with a wavelength of around 122 nanometres. As such, this radiation is fully absorbed by the Earth’s atmosphere. Only red-shifted Lyman-alpha emission from extremely distant galaxies has a long enough wavelength to pass through Earth’s atmosphere unimpeded and be detected using ESO’s ground-based telescopes.



More Information

This research was presented in a paper titled “Nearly 100% of the sky is covered by Lyman-α emission around high redshift galaxies” which was published today in the journal Nature.

The team is composed of Lutz Wisotzki (Leibniz-Institut für Astrophysik Potsdam, Germany), Roland Bacon (CRAL - CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Université de Lyon, France), Jarle Brinchmann (Universiteit Leiden, the Netherlands; Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, Portugal), Sebastiano Cantalupo (ETH Zürich, Switzerland), Philipp Richter (Universität Potsdam, Germany), Joop Schaye (Universiteit Leiden, the Netherlands), Kasper B. Schmidt (Leibniz-Institut für Astrophysik Potsdam, Germany), Tanya Urrutia (Leibniz-Institut für Astrophysik Potsdam, Germany), Peter M. Weilbacher (Leibniz-Institut für Astrophysik Potsdam, Germany), Mohammad Akhlaghi (CRAL - CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, Université de Lyon, France), Nicolas Bouché (Université de Toulouse, France), Thierry Contini (Université de Toulouse, France), Bruno Guiderdoni (CRAL - CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, L’Université de Lyon, France), Edmund C. Herenz (Stockholms universitet, Sweden), Hanae Inami (L’Université de Lyon, France), Josephine Kerutt (Leibniz-Institut für Astrophysik Potsdam, Germany), Floriane Leclercq (CRAL - CNRS, Université Claude Bernard Lyon 1, ENS de Lyon,L’Université de Lyon, France), Raffaella A. Marino (ETH Zürich, Switzerland), Michael Maseda (Universiteit Leiden, the Netherlands), Ana Monreal-Ibero (Instituto Astrofísica de Canarias, Spain; Universidad de La Laguna, Spain), Themiya Nanayakkara (Universiteit Leiden, the Netherlands), Johan Richard (CRAL - CNRS, Université Claude Bernard Lyon 1, ENS de Lyon,L’Université de Lyon, France), Rikke Saust (Leibniz-Institut für Astrophysik Potsdam, Germany), Matthias Steinmetz (Leibniz-Institut für Astrophysik Potsdam, Germany), and Martin Wendt (Universität Potsdam, Germany).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 16 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a strategic partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.



Links



Contacts

Lutz Wisotzki
Leibniz-Institut für Astrophysik Potsdam
Potsdam, Germany
Tel: +49 331 7499 532
Email: lwisotzki@aip.de

Roland Bacon
MUSE Principal Investigator / Lyon Centre for Astrophysics Research (CRAL)
Lyon, France
Cell: +33 6 08 09 14 27
Email: rmb@obs.univ-lyon1.fr

Calum Turner
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6670
Email: pio@eso.org


Source: ESO/News


Thursday, August 03, 2017

Cutting-edge Adaptive Optics Facility Sees First Light

PR Image eso1724a
The planetary nebula IC 4406 seen with MUSE and the AOF 

NGC 6369 before and after the AOF 

The planetary nebula NGC 6563 observed with the AOF

The AOF + MUSE at work

The AOF + MUSE at work

UT4 and the AOF at work

The powerful lasers of the AOF

NGC 6369 

ESO 338-4 

The planetary nebula NGC 6563 observed with MUSE and the AOF 



Videos
 
ESOcast 119: AOF First Light
ESOcast 119: AOF First Light

NGC 6369 AO on/off crossfade
NGC 6369 AO on/off crossfade



Image Comparisons

NGC 6369 with and without the AOF
NGC 6369 with and without the AOF

NGC 6563 with and without the AOF
NGC 6563 with and without the AOF 



Spectacular improvement in the sharpness of MUSE images

The Unit Telescope 4 (Yepun) of ESO’s Very Large Telescope (VLT) has now been transformed into a fully adaptive telescope. After more than a decade of planning, construction and testing, the new Adaptive Optics Facility (AOF) has seen first light with the instrument MUSE, capturing amazingly sharp views of planetary nebulae and galaxies. The coupling of the AOF and MUSE forms one of the most advanced and powerful technological systems ever built for ground-based astronomy.

The Adaptive Optics Facility (AOF) is a long-term project on ESO’s Very Large Telescope (VLT) to provide an adaptive optics system for the instruments on Unit Telescope 4 (UT4), the first of which is MUSE (the Multi Unit Spectroscopic Explorer) [1]. Adaptive optics works to compensate for the blurring effect of the Earth’s atmosphere, enabling MUSE to obtain much sharper images and resulting in twice the contrast previously achievable. MUSE can now study even fainter objects in the Universe.

Now, even when the weather conditions are not perfect, astronomers can still get superb image quality thanks to the AOF,” explains Harald Kuntschner, AOF Project Scientist at ESO.

Following a battery of tests on the new system, the team of astronomers and engineers were rewarded with a series of spectacular images. Astronomers were able to observe the planetary nebulae IC 4406, located in the constellation Lupus (The Wolf), and NGC 6369, located in the constellation Ophiuchus (The Serpent Bearer). The MUSE observations using the AOF showed dramatic improvements in the sharpness of the images, revealing never before seen shell structures in IC 4406 [2].

The AOF, which made these observations possible, is composed of many parts working together. They include the Four Laser Guide Star Facility (4LGSF) and the very thin deformable secondary mirror of UT4 [3] [4]. The 4LGSF shines four 22-watt laser beams into the sky to make sodium atoms in the upper atmosphere glow, producing spots of light on the sky that mimic stars. Sensors in the adaptive optics module GALACSI (Ground Atmospheric Layer Adaptive Corrector for Spectroscopic Imaging) use these artificial guide stars to determine the atmospheric conditions.

One thousand times per second, the AOF system calculates the correction that must be applied to change the shape of the telescope’s deformable secondary mirror to compensate for atmospheric disturbances. In particular, GALACSI corrects for the turbulence in the layer of atmosphere up to one kilometre above the telescope. Depending on the conditions, atmospheric turbulence can vary with altitude, but studies have shown that the majority of atmospheric disturbance occurs in this “ground layer” of the atmosphere.

The AOF system is essentially equivalent to raising the VLT about 900 metres higher in the air, above the most turbulent layer of atmosphere,” explains Robin Arsenault, AOF Project Manager. “In the past, if we wanted sharper images, we would have had to find a better site or use a space telescope — but now with the AOF, we can create much better conditions right where we are, for a fraction of the cost!

The corrections applied by the AOF rapidly and continuously improve the image quality by concentrating the light to form sharper images, allowing MUSE to resolve finer details and detect fainter stars than previously possible. GALACSI currently provides a correction over a wide field of view, but this is only the first step in bringing adaptive optics to MUSE. A second mode of GALACSI is in preparation and is expected to see first light early 2018. This narrow-field mode will correct for turbulence at any altitude, allowing observations of smaller fields of view to be made with even higher resolution.

Sixteen years ago, when we proposed building the revolutionary MUSE instrument, our vision was to couple it with another very advanced system, the AOF,” says Roland Bacon, project lead for MUSE. “The discovery potential of MUSE, already large, is now enhanced still further. Our dream is becoming true.”

One of the main science goals of the system is to observe faint objects in the distant Universe with the best possible image quality, which will require exposures of many hours. Joël Vernet, ESO MUSE and GALACSI Project Scientist, comments: “In particular, we are interested in observing the smallest, faintest galaxies at the largest distances. These are galaxies in the making — still in their infancy — and are key to understanding how galaxies form.”

Furthermore, MUSE is not the only instrument that will benefit from the AOF. In the near future, another adaptive optics system called GRAAL will come online with the existing infrared instrument HAWK-I, sharpening its view of the Universe. That will be followed later by the powerful new instrument ERIS.

ESO is driving the development of these adaptive optics systems, and the AOF is also a pathfinder for ESO’s Extremely Large Telescope,” adds Arsenault. “Working on the AOF has equipped us — scientists, engineers and industry alike — with invaluable experience and expertise that we will now use to overcome the challenges of building the ELT.”



Notes

[1] MUSE is an integral-field spectrograph, a powerful instrument that produces a 3D data set of a target object, where each pixel of the image corresponds to a spectrum of the light from the object. This essentially means that the instrument creates thousands of images of the object at the same time, each at a different wavelength of light, capturing a wealth of information.


[2] IC 4406 has previously been observed with the VLT (eso9827a).

[3] At just over one metre in diameter, this is the largest adaptive optics mirror ever produced and demanded cutting-edge technology. It was mounted on UT4 in 2016 (ann16078) to replace the telescope’s original conventional secondary mirror.

[4] Other tools to optimise the operation of the AOF have been developed and are now operational. These include an extension of the Astronomical Site Monitor software that monitors the atmosphere to determine the altitude at which the turbulence is occurring, and the Laser Traffic Control System (LTCS) that prevents other telescopes looking into the laser beams or at the artificial stars themselves and potentially affecting their observations.



More Information

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.



Links



Contacts

Harald Kuntschner
ESO, AOF Project Scientist
Garching bei München, Germany
Tel: +49 89 3200 6465
Email:
hkuntsch@eso.org

Richard Hook
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email:
rhook@eso.org

Joël Vernet
ESO MUSE and GALACSI Project Scientist
Garching bei München, Germany
Tel: +49 89 3200 6579
Email:
jvernet@eso.org

Source: ESO/News

Friday, February 27, 2015

ESOcast 72: Looking Deeply into the Universe in 3D


MUSE goes beyond Hubble in the Hubble Deep Field South

MUSE stares at the Hubble Deep Field South

The Hubble Deep Field South in the constellation of Tucana

Hubble Deep Field South — Multiple Windows on the Universe



*************************************************************************************************************************************


Videos

ESOcast 72 – Looking Deeply into the Universe in 3D
ESOcast 72 – Looking Deeply into the Universe in 3D

MUSE view of the Hubble Deep Field South
MUSE view of the Hubble Deep Field South

MUSE view of the Hubble Deep Field South
MUSE view of the Hubble Deep Field South

MUSE view of the Hubble Deep Field South
MUSE view of the Hubble Deep Field South

A video view of MUSE data of the Hubble Deep Field South
A video view of MUSE data of the Hubble Deep Field South


The MUSE instrument on ESO’s Very Large Telescope has given astronomers the best ever three-dimensional view of the deep Universe. After staring at the Hubble Deep Field South region for only 27 hours, the new observations reveal the distances, motions and other properties of far more galaxies than ever before in this tiny piece of the sky. They also go beyond Hubble and reveal previously invisible objects.

By taking very long exposure pictures of regions of the sky, astronomers have created many deep fields that have revealed much about the early Universe. The most famous of these was the original Hubble Deep Field, taken by the NASA/ESA Hubble Space Telescope over several days in late 1995. This spectacular and iconic picture rapidly transformed our understanding of the content of the Universe when it was young. It was followed two years later by a similar view in the southern sky — the Hubble Deep Field South.

But these images did not hold all the answers — to find out more about the galaxies in the deep field images, astronomers had to carefully look at each one with other instruments, a difficult and time-consuming job. But now, for the first time, the new MUSE instrument can do both jobs at once — and far more quickly.

One of the first observations using MUSE after it was commissioned on the VLT in 2014 was a long hard look at the Hubble Deep Field South (HDF-S). The results exceeded expectations.

After just a few hours of observations at the telescope, we had a quick look at the data and found many galaxies — it was very encouraging. And when we got back to Europe we started exploring the data in more detail. It was like fishing in deep water and each new catch generated a lot of excitement and discussion of the species we were finding,”  explained Roland Bacon (Centre de Recherche Astrophysique de Lyon, France, CNRS) principal investigator of the MUSE instrument and leader of the commissioning team.

For every part of the MUSE view of HDF-S there is not just a pixel in an image, but also a spectrum revealing the intensity of the light’s different component colours at that point — about 90 000 spectra in total [1]. These can reveal the distance, composition and internal motions of hundreds of distant galaxies — as well as catching a small number of very faint stars in the Milky Way.

Even though the total exposure time was much shorter than for the Hubble images, the HDF-S MUSE data revealed more than twenty very faint objects in this small patch of the sky that Hubble did not record at all [2].

The greatest excitement came when we found very distant galaxies that were not even visible in the deepest Hubble image. After so many years of hard work on the instrument, it was a powerful experience for me to see our dreams becoming reality,” adds Roland Bacon.

By looking carefully at all the spectra in the MUSE observations of the HDF-S, the team measured the distances to 189 galaxies. They ranged from some that were relatively close, right out to some that were seen when the Universe was less than one billion years old. This is more than ten times the number of measurements of distance than had existed before for this area of sky.

For the closer galaxies, MUSE can do far more and look at the different properties of different parts of the same galaxy. This reveals how the galaxy is rotating and how other properties vary from place to place. This is a powerful way of understanding how galaxies evolve through cosmic time.

Now that we have demonstrated MUSE’s unique capabilities for exploring the deep Universe, we are going to look at other deep fields, such as the Hubble Ultra Deep field. We will be able to study thousands of galaxies and to discover new extremely faint and distant galaxies. These small infant galaxies, seen as they were more than 10 billion years in the past, gradually grew up to become galaxies like the Milky Way that we see today,” concludes Roland Bacon.

 

Notes

 

[1] Each spectrum covers a range of wavelengths from the blue part of the spectrum into the near-infrared (475‒930 nanometres).

[2] MUSE is particularly sensitive to objects that emit most of their energy at a few particular wavelengths as these show up as bright spots in the data. Galaxies in the early Universe typically have such spectra, as they contain hydrogen gas glowing under the ultraviolet radiation from hot young stars.

 

More information

 

This research was presented in a paper entitled “The MUSE 3D view of the Hubble Deep Field South” by R. Bacon et al., to appear in the journal Astronomy & Astrophysics on 26 February 2015.

The team is composed of R. Bacon (Observatoire de Lyon, CNRS, Université Lyon, Saint Genis Laval, France [Lyon]), J. Brinchmann (Leiden Observatory, Leiden University, Leiden, The Netherlands [Leiden]), J. Richard (Lyon), T. Contini (Institut de Recherche en Astrophysique et Planétologie, CNRS, Toulouse, France; Université de Toulouse, France [IRAP]), A. Drake (Lyon), M. Franx (Leiden), S. Tacchella (ETH Zurich, Institute of Astronomy, Zurich, Switzerland [ETH]), J. Vernet (ESO, Garching, Germany), L. Wisotzki (Leibniz-Institut für Astrophysik Potsdam, Potsdam, Germany [AIP]), J. Blaizot (Lyon), N. Bouché (IRAP), R. Bouwens (Leiden), S. Cantalupo (ETH), C.M. Carollo (ETH), D. Carton (Leiden), J. Caruana (AIP), B. Clément (Lyon), S. Dreizler (Institut für Astrophysik, Universität Göttingen, Göttingen, Germany [AIG]), B. Epinat (IRAP; Aix Marseille Université, CNRS, Laboratoire d’Astrophysique de Marseille, Marseille, France), B. Guiderdoni (Lyon), C. Herenz (AIP), T.-O. Husser (AIG), S. Kamann (AIG), J. Kerutt (AIP), W. Kollatschny (AIG), D. Krajnovic (AIP), S. Lilly (ETH), T. Martinsson (Leiden), L. Michel-Dansac (Lyon), V. Patricio (Lyon), J. Schaye (Leiden), M. Shirazi (ETH), K. Soto (ETH), G. Soucail (IRAP), M. Steinmetz (AIP), T. Urrutia (AIP), P. Weilbacher (AIP) and T. de Zeeuw (ESO, Garching, Germany; Leiden).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

 

Links

 

Contacts


Roland Bacon
CRAL - Centre de recherche astrophysique de Lyon
Saint-Genis-Laval, France
Tel: +33 478 86 85 59
Cell: +33 608 09 14 27
Email:
roland.bacon@univ-lyon1.fr

Richard Hook
ESO education and Public Outreach Department
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email:
rhook@eso.org

Source: ESO


Monday, November 10, 2014

MUSE Reveals True Story Behind Galactic Crash

MUSE view of the ram-pressure stripped galaxy ESO 137-001
 
MUSE view of the ram-pressure stripped galaxy ESO 137-001
 
The galaxy ESO 137-001 in the constellation of Triangulum Australe
 
Wide-field view of the sky around the galaxy ESO 137-001
 
Hubble and Chandra composite of ESO 137-001

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Videos

Zooming in on ESO 137-001
Zooming in on ESO 137-001

MUSE shows ESO 137-001 in three dimensions
MUSE shows ESO 137-001 in three dimensions 


The new MUSE instrument on ESO’s Very Large Telescope (VLT) has provided researchers with the best view yet of a spectacular cosmic crash. The new 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.

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 [1].

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 [2].

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.

The observations show that the outskirts of ESO 137-001 are already completely devoid of gas. This is a result of the cluster gas — heated to millions of degrees — pushing the cooler gas out of ESO 137-001 as this drives towards the centre of the cluster. This happens first in the spiral arms where the stars and matter are more thinly spread than at the centre, and gravity has only a relatively weak hold over the gas. In the centre of the galaxy, however, the gravitational pull is strong enough to hold out longer in this cosmic tug-of-war and gas is still observed.

Eventually, all of the galactic gas will be swept away into bright streaks behind ESO 137-001 — telltale remnants of this dramatic robbery. The gas that is torn away from the galaxy is mixed with the hot cluster gas to form magnificent tails extending to a distance of over 200 000 light-years. The team had a closer look at these streams of gas to better understand the turbulence created by the interaction.

Surprisingly the new MUSE observations of this gas plume show that the gas continues to rotate in same way the galaxy does, even after being swept out into space. Furthermore, researchers were able to determine that the rotation of stars in ESO 137-001 remains unchanged. This provides further evidence for the cluster gas, not gravity, being responsible for stripping the galaxy [3].

Matteo Fossati (Universitäts-Sternwarte München and Max-Planck-Institut für extraterrestrische Physik, Garching, Germany) and a co-author of the paper concludes: “With the details revealed by MUSE we are getting closer to fully understanding the processes that go on in such collisions. We see the motions of the galaxy and the gas in detail — something that wouldn’t be possible without the new and unique MUSE instrument. These and future observations will help us develop a better idea of what is driving the evolution of galaxies.” 


Notes

[1] MUSE is the first large integral field spectrograph ever installed at an 8-metre telescope. As a comparison, previous studies of ESO 137-001 collected no more than 50 spectra.

[2] The NASA/ESA Hubble Space Telescope has provided a spectacular image of this object — but, unlike MUSE, cannot reveal the motions of the material.

[3] If gravity were to play a role in the stripping process, the researchers would have expected to see disruptions within the galaxy.

 
More Information

This research was presented in a paper entitled “MUSE sneaks a peek at extreme ram-pressure stripping events. I. A kinematic study of the archetypal galaxy ESO137-001” to appear in Monthly Notices of the Royal Astronomical Society on 10 November 2014.

The team is composed of Michele Fumagalli (Extragalactic Astronomy Group and Institute for Computational Cosmology, Durham University, United Kingdom), Matteo Fossati (Universitäts-Sternwarte München and Max-Planck-Institut für extraterrestrische Physik, Garching, Germany), George K. T. Hau (ESO, Santiago, Chile), Giuseppe Gavazzi (Università di Milano-Bicocca, Italy), Richard Bower (Extragalactic Astronomy Group and Institute for Computational Cosmology, Durham University, United Kingdom), Alessandro Boselli (Laboratoire d'Astrophysique de Marseille, France) and Ming Sun (Department of Physics, University of Alabama, USA).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.  


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Contacts

Michele Fumagalli
Institute for Computational Cosmology, Durham University
Durham, United Kingdom
Tel: +44 191 334 3789
Email:
michele.fumagalli@durham.ac.uk

Matteo Fossati
Universitäts-Sternwarte München and Max-Planck-Institut für extraterrestrische Physik
Munich, Germany
Tel: +49 89 30000 3890
Email:
mfossati@mpe.mpg.de

Richard Hook
ESO education and Public Outreach Department
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591
Email:
rhook@eso.org

Source: ESO