The final frontier of the Frontier Fields

ESA - Hubble Space Telescope logo.

4 May 2017

The NASA/ESA Hubble Telescope has peered across six billion light years of space to resolve extremely faint features of the galaxy cluster Abell 370 that have not been seen before. Imaged here in stunning detail, Abell 370 is part of the Frontier Fields programme which uses massive galaxy clusters to study the mysteries of dark matter and the very early Universe.

 The last of the Frontier Fields — Abell 370

Six billion light-years away in the constellation Cetus (the Sea Monster), Abell 370 is made up of hundreds of galaxies [1]. Already in the mid-1980s higher-resolution images of the cluster showed that the giant luminous arc in the lower left of the image was not a curious structure within the cluster, but rather an astrophysical phenomenon: the gravitationally lensed image of a galaxy twice as far away as the cluster itself. Hubble helped show that this arc is composed of two distorted images of an ordinary spiral galaxy that just happens to lie behind the cluster.

Abell 370 parallel field

Abell 370’s enormous gravitational influence warps the shape of spacetime around it, causing the light of background galaxies to spread out along multiple paths and appear both distorted and magnified. The effect can be seen as a series of streaks and arcs curving around the centre of the image. Massive galaxy clusters can therefore act like natural telescopes, giving astronomers a close-up view of the very distant galaxies behind the cluster — a glimpse of the Universe in its infancy, only a few hundred million years after the Big Bang.

Hubble Space Telescope

This image of Abell 370 was captured as part of the Frontier Fields programme, which used a whopping 630 hours of Hubble observing time, over 560 orbits of the Earth. Six clusters of galaxies were imaged in exquisite detail, including Abell 370 which was the very last one to be finished. An earlier image of this object  — using less observation time and therefore not recording such faint detail — was published in 2009.

Digitized sky survey image of Abell 370 (ground-based image)

During the cluster observations, Hubble also looked at six “parallel fields”, regions near the galaxy clusters which were imaged with the same exposure times as the clusters themselves. Each cluster and parallel field were imaged in infrared light by the Wide Field Camera 3 (WFC3), and in visible light by the Advanced Camera for Surveys (ACS).

Abell 370 (seen in 2009)

The Frontier Fields programme produced the deepest observations ever made of galaxy clusters and the magnified galaxies behind them. These observations are helping astronomers understand how stars and galaxies emerged out of the dark ages of the Universe, when space was dark, opaque, and filled with hydrogen.

Zoom-in on Abell 370

Studying massive galaxy clusters like Abell 370 also helps with measuring the distribution of normal matter and dark matter within such clusters [heic1506]. By studying its lensing properties, astronomers have determined that Abell 370 contains two large, separate clumps of dark matter, contributing to the evidence that this massive galaxy cluster is actually the result of two smaller clusters merging together.

Pan across Abell 370

Now that the observations for the Frontier Fields programme are complete, astronomers can use the full dataset to explore the clusters, their gravitational lensing effects and the magnified galaxies from the early Universe in full detail.

Increased depth of Abell 370

Notes:

[1] Galaxy clusters are the most massive structures in the Universe that are held together by gravity, generally thought to have formed when smaller groups of galaxies smashed into each other in ever-bigger cosmic collisions. Such clusters can contain up to 1000 galaxies, along with hot intergalactic gas that often shines brightly at X-ray wavelengths, all bound together primarily by the gravity of dark matter.

More information:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Hubblesite release: http://hubblesite.org/news_release/news/2017-20

Frontier Fields: https://frontierfields.org/

Wide Field Camera 3 (WFC3): http://spacetelescope.org/about/general/instruments/wfc3/

Advanced Camera for Surveys (ACS): http://spacetelescope.org/about/general/instruments/acs/

heic1506: http://www.spacetelescope.org/news/heic1506/

Images, Animation, Text,  Credits: NASA, ESA/Hubble, HST Frontier Fields/Digitized Sky Survey 2. Acknowledgment: Davide De Martin/Videos: ESA/Hubble/Music: Richard Hasbia "Stan Dart".

Best regards, Orbiter.ch

New Movie Shows Cassini's First Dive over Saturn

NASA & ESA - Cassini-Huygens Mission to Saturn & Titan patch.

May 4, 2017

Animation above: Cassini took a movie sequence of images during its first dive between Saturn and its rings on April 26, 2017. Animation Credits: NASA/JPL-Caltech.

A new movie sequence of images from NASA's Cassini spacecraft shows the view as the spacecraft swooped over Saturn during the first of its Grand Finale dives between the planet and its rings on April 26.

The movie comprises one hour of observations as the spacecraft moved southward over Saturn. It begins with a view of the swirling vortex at the planet's north pole, then heads past the outer boundary of the hexagon-shaped jet stream and beyond.

"I was surprised to see so many sharp edges along the hexagon's outer boundary and the eye-wall of the polar vortex," said Kunio Sayanagi, an associate of the Cassini imaging team based at Hampton University in Virginia, who helped produce the new movie. "Something must be keeping different latitudes from mixing to maintain those edges," he said.

Cassini's First Fantastic Dive Past Saturn

Video above: As NASA's Cassini spacecraft made its first-ever dive through the gap between Saturn and its rings on April 26, 2017, one of its imaging cameras took a series of rapid-fire images that were used to make this movie sequence. The video begins with a view of the vortex at Saturn's north pole, then heads past the outer boundary of the planet's hexagon-shaped jet stream and continues further southward. Video Credits: NASA/JPL.

Toward the end of the movie, the camera frame rotates as the spacecraft reorients to point its large, saucer-shaped antenna in the direction of the spacecraft's motion. The antenna was used as a protective shield during the crossing of Saturn's ring plane.

As the movie frames were captured, the Cassini spacecraft's altitude above the clouds dropped from 45,000 to 4,200 miles (72,400 to 6,700 kilometers). As this occurred, the smallest resolvable features in the atmosphere changed from 5.4 miles (8.7 kilometers) per pixel to 0.5 mile (810 meters) per pixel.

Image above: NASA's Cassini spacecraft is shown diving through the gap between Saturn and its rings in this artist's depiction. Image Credits: NASA/JPL-Caltech.

"The images from the first pass were great, but we were conservative with the camera settings. We plan to make updates to our observations for a similar opportunity on June 28 that we think will result in even better views," said Andrew Ingersoll, a member of the Cassini imaging team based at Caltech in Pasadena, California.

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena, California, manages the mission for the agency's Science Mission Directorate in Washington. JPL is a division of the Caltech in Pasadena. The Cassini imaging operations center is based at Space Science Institute in Boulder, Colorado.

Related article:

Cassini Spacecraft Dives Between Saturn and Its Rings
http://orbiterchspacenews.blogspot.ch/2017/04/cassini-spacecraft-dives-between-saturn.html

For more information about Cassini, visit:

http://www.nasa.gov/cassini

http://saturn.jpl.nasa.gov

http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/JPL/Preston Dyches/CICLOPS/Space Science Institute/Steve Mullins.

Greetings, Orbiter.ch

Crew Researches Bone Loss, New Exercises and Emergency Training

ISS - Expedition 51 Mission patch.

May 3, 2017

International Space Station (ISS). Animation Credit: NASA

The Expedition 51 quintet studied how long-term space missions affect bone loss and explored new ways to exercise in space today. The crew also reviewed emergency procedures and equipment onboard the International Space Station.

Astronauts Peggy Whitson and Thomas Pesquet set up samples today for the OsteoOmics bone study that will last four weeks on the station. Doctors are researching the molecular mechanisms that impact the bones of astronauts living in space. The experiment could lead to therapeutic insights improving the health of astronauts in space and humans on Earth.

Image above: The Expedition 51 crew poses for a portrait with the captured Cygnus resupply ship just outside the cupola. In the foreground is Flight Engineer Fyodor Yurchikhin. In the background from left, are Commander Peggy Whitson and Flight Engineers Jack Fischer, Thomas Pesquet and Oleg Novitskiy. Image Credit: NASA.

New Flight Engineer Jack Fischer performed an ultrasound scan of his leg muscles with assistance from Whitson and remote guidance from ground personnel. The ultrasound data is being collected for the Sprint study that is exploring the benefits of high-intensity, low-volume exercise to maintain muscle, bone and heart functions.

Whitson and Fischer then joined veteran cosmonaut Fyodor Yurchikhin for a couple of hours of emergency training. The trio took note of safety gear locations, followed escape paths to the docked Soyuz vehicles and inspected hatches for proper clearances.

Related links:

Expedition 51: https://www.nasa.gov/mission_pages/station/expeditions/expedition51/index.html

Sprint study: https://www.nasa.gov/mission_pages/station/research/experiments/972.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Image (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

CERN CASTs new limits on dark matter

CERN - European Organization for Nuclear Research logo.

May 3, 2017

In a paper published today in Nature Physics, the CAST experiment at CERN presented new results on the properties of axions – hypothetical particles that would interact very weakly with ordinary matter and therefore could explain the mysterious dark matter that appears to make up most of the matter in the universe.

Axions were postulated by theorists decades ago, initially to solve an important issue in the Standard Model of particle physics related to the differences between matter and antimatter. The particle was named after a brand of washing detergent, since its existence would allow the theory to be “cleaned up”.

A variety of Earth- and space-based observatories are searching possible locations where axions could be produced, ranging from the inner Earth to the galactic centre and right back to the Big Bang.

Image above: CAST, CERN's axion solar telescope, moves on its rail to follow the Sun (Image: Max Brice/CERN).

The CERN Axion Solar Telescope (CAST) experiment is looking for axions from the sun using a special telescope called a helioscope constructed from a test magnet originally built for the Large Hadron Collider. The 10-metre-long superconducting magnet acts like a viewing tube and is pointed directly at the sun: any solar axions entering the tube would be converted by its strong magnetic field into X-ray photons, which would be detected at either end of the magnet by specialised detectors. Since 2003, the CAST helioscope, mounted on a movable platform, has tracked the movement of the sun for an hour and a half at dawn and an hour and a half at dusk, over several months each year. The detector is aligned with the sun with a precision of about one hundredth of a degree.

In the paper published today, based on data recorded between 2012 and 2015, CAST finds no evidence for solar axions. This has allowed the collaboration to set the best limits to date on the strength of the coupling between axions and photons for all possible axion masses to which CAST is sensitive. “The limits concern a part of the axion parameter space that is still favoured by current theoretical predictions and is very difficult to explore experimentally,” explains the deputy spokesperson for CAST, Igor Garcia Irastorza. “For the first time, we have been able to set limits that are similar to the more restrictive constraints set by astrophysical observations,” he says.

CERN - CASTs new limits on dark matter

Video above: Timelapse video of CAST following the Sun in the morning and in the evening (Video: Madalin-Mihai Rosu/CERN).

Since 2015, CAST has broadened its research at the low-energy frontier to include searches for other weakly-interacting particles from the dark energy sector, such as “solar chameleons”. The experience gained by CAST over the past 15 years will also help physicists define the detection technologies suitable for a proposed, much larger, next-generation axion helioscope called IAXO.

“Even though we have not been able to observe the ubiquitous axion yet, CAST has surpassed even the sensitivity originally expected, thanks to CERN’s support and unrelenting work by CASTers,” says CAST spokesperson Konstantin Zioutas. “CAST’s results are still a point of reference in our field.”

More information on the results can be found in the scientific paper: http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys4109.html

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related link:

CAST experiment: http://home.cern/about/experiments/cast

For more information about European Organization for Nuclear Research (CERN), Visit: http://home.cern/

Image (mentioned), Video (mentioned), Text, Credits: CERN, by Stefania Pandolfi.

Best regards, Orbiter.ch

North Pole of Enceladus

NASA- Cassini International logo.

May 3, 2017

In the north, Enceladus' surface appears to be about as old as any in the solar system. The south, however, is an entirely different story.

The north polar area of Enceladus (313 miles or 504 kilometers across) seen here is heavily cratered, an indication that the surface has not been renewed since quite long ago. But the south polar region shows signs of intense geologic activity, most prominently focused around the long fractures known as "tiger stripes" that spray gas and tiny particles from the moon.

This view looks toward the leading side of Enceladus. North on Enceladus is up and rotated 38 degrees to the left. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Nov. 27, 2016.

The view was acquired at a distance of approximately 20,000 miles (32,000 kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 85 degrees. Image scale is 620 feet (190 meters) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit https://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini . The Cassini imaging team homepage is at http://ciclops.org and ESA's website: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Text, Credits: NASA/Jon Nelson/JPL.

Greetings, Orbiter.ch

The LHC has restarted for its 2017 run

CERN - European Organization for Nuclear Research logo.

May 3, 2017

On April 29, 2017, the LHC once again began circulating beams of protons, for the first time this year. This follows a 17-week-long extended technical stop.

Over the past month, after the completion of the maintenance work that began in December 2016, each of the machines in the accelerator chain have, in turn, been switched on and checked until this weekend when the LHC, the final machine in the chain, could be restarted by the Operations team.

“It’s like an orchestra, everything has to be timed and working very nicely together. Once each of the parts is working properly, that’s when the beam goes in, in phases from one machine to the next all the way up to the LHC,” explains Rende Steerenberg, who leads the operations group responsible for the whole accelerator complex, including the LHC.

Each year, the machines shut down over the winter break to enable technicians and engineers to perform essential repairs and upgrades, but this year the stop was scheduled to run longer, allowing more complex work to take place. This year included the replacement of a superconducting magnet in the LHC, the installation of a new beam dump in the Super Proton Synchrotron and a massive cable removal campaign.

Among other things, these upgrades will allow the collider to reach a higher integrated luminosity – the higher the luminosity, the more data the experiments can gather to allow them to observe rare processes.

Image above: Final tests were performed in the LHC at the end of April, ready for the restart this weekend (Image: Maximilien Brice/ CERN).

“Our aim for 2017 is to reach an integrated luminosity of 45 fb-1 [they reached 40 fb-1 last year] and preferably go beyond. The big challenge is that, while you can increase luminosity in different ways – you can put more bunches in the machine, you can increase the intensity per bunch and you can also increase the density of the beam – the main factor is actually the amount of time you stay in stable beams,” explains Steerenberg.

In 2016, the machine was able to run with stable beams – beams from which the researchers can collect data – for around 49 per cent of the time, compared to just 35 per cent the previous year. The challenge the team faces this year is to maintain this or (preferably) increase it further.

The team will also be using the 2017 run to test new optics settings – which provide the potential for even higher luminosity and more collisions.

“We’re changing how we squeeze the beam to its small size in the experiments, initially to the same value as last year, but with the possibility to go to even smaller sizes later, which means we can push the limits of the machine further. With the new SPS beam dump and the improvements to the LHC injector kickers, we can inject more particles per bunch and more bunches, hence more collisions,” he concludes.

For the first few weeks only, a few bunches of particles will be circulating in the LHC to debug and validate the machine. Bunches will gradually increase over the coming weeks until there are enough particles in the machine to begin collisions and to start collecting physics data.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Learn more about the restart:

Who switches on the LHC?: http://home.cern/about/updates/2017/04/who-switches-lhc

Everything you ever wanted to know about the LHC: http://home.cern/topics/large-hadron-collider

For more information about European Organization for Nuclear Research (CERN), Visit: http://home.cern/

Image (mentioned), Text, Credits: CERN, by Harriet Jarlett.

Best regards, Orbiter.ch, very close neighbor of CERN (Still no black hole!)

VISTA Peeks Through the Small Magellanic Cloud’s Dusty Veil

ESO - European Southern Observatory logo.

3 May 2017

VISTA’s view of the Small Magellanic Cloud

The Small Magellanic Cloud galaxy is a striking feature of the southern sky even to the unaided eye. But visible-light telescopes cannot get a really clear view of what is in the galaxy because of obscuring clouds of interstellar dust. VISTA’s infrared capabilities have now allowed astronomers to see the myriad of stars in this neighbouring galaxy much more clearly than ever before. The result is this record-breaking image — the biggest infrared image ever taken of the Small Magellanic Cloud — with the whole frame filled with millions of stars.

The Small Magellanic Cloud (SMC) is a dwarf galaxy, the more petite twin of the Large Magellanic Cloud (LMC). They are two of our closest galaxy neighbours in space — the SMC lies about 200 000 light-years away, just a twelfth of the distance to the more famous Andromeda Galaxy.  Both are also rather peculiarly shaped, as a result of interactions with one another and with the Milky Way itself.

Highlights from VISTA's view of the Small Magellanic Cloud

Their relative proximity to Earth makes the Magellanic Clouds ideal candidates for studying how stars form and evolve. However, while the distribution and history of star formation in these dwarf galaxies were known to be complex, one of the biggest obstacles to obtaining clear observations of star formation in galaxies is interstellar dust. Enormous clouds of these tiny grains scatter and absorb some of the radiation emitted from the stars — especially visible light — limiting what can be seen by telescopes here on Earth. This is known as dust extinction.

The SMC is full of dust, and the visible light emitted by its stars suffers significant extinction. Fortunately, not all electromagnetic radiation is equally affected by dust. Infrared radiation passes through interstellar dust much more easily than visible light, so by looking at the infrared light from a galaxy we can learn about the new stars forming within the clouds of dust and gas.

The location of the Small Magellanic Cloud in the constellation of Tucana

VISTA, the Visible and Infrared Survey Telescope, was designed to image infrared radiation. The VISTA Survey of the Magellanic Clouds (VMC) is focused on mapping the star formation history of the SMC and LMC, as well as mapping their three-dimensional structures. Millions of SMC stars have been imaged in the infrared thanks to the VMC, providing an unparalleled view almost unaffected by dust extinction.

The whole frame of this massive image is filled with stars belonging to the Small Magellanic Cloud. It also includes thousands of background galaxies and several bright star clusters, including 47 Tucanae at the right of the picture, which lies much closer to the Earth than the SMC. The zoomable image will show you the SMC as you have never seen it before!

A close-up look at VISTA's view of the Small Magellanic Cloud

The wealth of new information in this 1.6 gigapixel image (43 223 x 38 236 pixels) has been analysed by an international team led by Stefano Rubele of the University of Padova. They have used cutting-edge stellar models to yield some surprising results.

The VMC has revealed that most of the stars within the SMC formed far more recently than those in larger neighbouring galaxies. This early result from the survey is just a taster of the new discoveries still to come, as the survey continues to fill in blind spots in our maps of the Magellanic Clouds.

Comparison of the Small Magellanic Cloud in infrared and visible light 

More information:

This research was presented in the paper "The VMC survey – XIV. First results on the look-back time star formation rate tomography of the Small Magellanic Cloud", in the journal Monthly Notices of the Royal Astronomical Society.

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 Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.

Links:

ESOcast 105 Light: Starstruck by the Small Magellanic Cloud (4K UHD): http://www.eso.org/public/videos/eso1714a/

Zoomable version of the image: https://www.eso.org/public/images/eso1714a/zoomable/

Research paper: https://www.eso.org/public/archives/releases/sciencepapers/eso1714/eso1714a.pdf

Photos of VISTA: http://www.eso.org/public/images/archive/category/surveytelescopes/?search=VISTA

VISTA Survey of the Magellanic Clouds (VMC): https://www.eso.org/public/teles-instr/surveytelescopes/vista/surveys/

Visible and Infrared Survey Telescope (VISTA): http://www.eso.org/public/teles-instr/surveytelescopes/vista/

University of Padova: http://www.dfa.unipd.it/

Images, Text, Credits: ESO/Richard Hook/Leibniz-Institut für Astrophysik Potsdam (AIP)/Maria-Rosa Cioni/VISTA VMC/IAU and Sky & Telescope/Videos: ESO/VISTA VMC/Digitized Sky Survey 2/N. Risinger (skysurvey.org). Music: Astral electronic.

Best regards, Orbiter.ch