Hubble observations cast further doubt on how globular clusters formed

ESA - Hubble Space Telescope logo.

20 November 2014

The riddle of the missing stars

 Four globular clusters in Fornax

Thanks to the NASA/ESA Hubble Space Telescope, some of the most mysterious cosmic residents have just become even more puzzling. New observations of globular clusters in a small galaxy show they are very similar to those found in the Milky Way, and so must have formed in a similar way. One of the leading theories on how these clusters form predicts that globular clusters should only be found nestled in among large quantities of old stars. But these old stars, though rife in the Milky Way, are not present in this small galaxy, and so, the mystery deepens.

Four globular clusters in Fornax — annotated

Globular clusters — large balls of stars that orbit the centres of galaxies, but can lie very far from them — remain one of the biggest cosmic mysteries. They were once thought to consist of a single population of stars that all formed together. However, research has since shown that many of the Milky Way's globular clusters had far more complex formation histories and are made up of at least two distinct populations of stars.

Globular cluster Fornax 1

Of these populations, around half the stars are a single generation of normal stars that were thought to form first, and the other half form a second generation of stars, which are polluted with different chemical elements. In particular, the polluted stars contain up to 50-100 times more nitrogen than the first generation of stars.

Globular cluster Fornax 2

The proportion of polluted stars found in the Milky Way's globular clusters is much higher than astronomers expected, suggesting that a large chunk of the first generation star population is missing. A leading explanation for this is that the clusters once contained many more stars but a large fraction of the first generation stars were ejected from the cluster at some time in its past.

Globular cluster Fornax 3

This explanation makes sense for globular clusters in the Milky Way, where the ejected stars could easily hide among the many similar, old stars in the vast halo, but the new observations, which look at this type of cluster in a much smaller galaxy, call this theory into question.

Globular cluster Fornax 5

Astronomers used Hubble's Wide Field Camera 3 (WFC3) to observe four globular clusters in a small nearby galaxy known as the Fornax Dwarf Spheroidal galaxy [1].

Fornax galaxy with four globular clusters marked

"We knew that the Milky Way's clusters were more complex than was originally thought, and there are theories to explain why. But to really test our theories about how these clusters form we needed to know what happened in other environments," says Søren Larsen of Radboud University in Nijmegen, the Netherlands, lead author of the new paper. "Before now we didn’t know whether globular clusters in smaller galaxies had multiple generations or not, but our observations show clearly that they do!"

Fornax dwarf galaxy

The astronomers' detailed observations of the four Fornax clusters show that they also contain a second polluted population of stars [2] and indicate that not only did they form in a similar way to one another, their formation process is also similar to clusters in the Milky Way. Specifically, the astronomers used the Hubble observations to measure the amount of nitrogen in the cluster stars, and found that about half of the stars in each cluster are polluted at the same level that is seen in Milky Way's globular clusters.

Hubble and the sunrise over Earth

This high proportion of polluted second generation stars means that the Fornax globular clusters' formation should be covered by the same theory as those in the Milky Way.

Based on the number of polluted stars in these clusters they would have to have been up to ten times more massive in the past, before kicking out huge numbers of their first generation stars and reducing to their current size. But, unlike the Milky Way, the galaxy that hosts these clusters doesn't have enough old stars to account for the huge number that were supposedly banished from the clusters.

Globular cluster in 3D

"If these kicked-out stars were there, we would see them — but we don't!" explains Frank Grundahl of Aarhus University in Denmark, co-author on the paper. "Our leading formation theory just can't be right. There's nowhere that Fornax could have hidden these ejected stars, so it appears that the clusters couldn't have been so much larger in the past."

Structure of a globular cluster

This finding means that a leading theory on how these mixed generation globular clusters formed cannot be correct and astronomers will have to think once more about how these mysterious objects, in the Milky Way and further afield, came to exist.

The new work is detailed in a paper published today, 20 November 2014, in The Astrophysical Journal.

Notes:

[1] The Milky Way’s gravity keeps Fornax orbiting around us as a satellite galaxy.

[2] The clusters studied were named Fornax 1, 2, 3, and 5. Fornax 1, 3, and 5 are made up of approximately 40% first generation stars to 60% polluted second generation ones, while Fornax 2 contains around 60% first generation and 40% second generation.
Notes for editors

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

The international team of astronomers in this study consists of S. Larsen (Radboud University, the Netherlands), J. P Brodie (University of California, USA), F. Grundahl (Aarhus University, Denmark), and J. Strader (Michigan State University, USA).

Links:

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

Link to science paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1425a.pdf

Images, Text, Credits: NASA, ESA, S. Larsen (Radboud University, the Netherlands)/ESO/Digitized Sky Survey 2/Videos: ESA/Hubble/M. Kornmesser.

Best regards, Orbiter.ch

Transport cargo ship Progress M-24M has completed its mission

ROSCOSMOS -Russian Vehicles patch.

11.20.2014

November 20, 2014 at 2:46 Moscow time in a predetermined area of the Pacific Ocean made of non-combustible residues flooding cargo vehicle (THC) Progress M-24M. In accordance with the program laid down in the ship's onboard computer experts Mission Control Center (MCC) FSUE TsNIIMash, at 2:00 MSK on "space truck" was included on the inhibition of the propulsion system, and then began a controlled reduction of THC from orbit.

Image above: Progress Spacecraft 42P reentry plasma trail viewed from the International Space Station. Image Credit: NASA.

Carrier rocket Soyuz-U with TGC Progress M-24M was launched from the Baikonur Cosmodrome July 24, 2014 at 01:44 Moscow time. July 24, 2014 at 07:31 MSK was carried out docking cargo spacecraft Progress M-24M with the International Space Station. Docked to the docking bay Pierce (CO1) of the Russian segment of the ISS was carried out in an automatic mode.
Cargo spacecraft delivered to ISS about 2.3 tons of cargo, including fuel, oxygen, food, equipment for scientific experiments and parcels for the crew.

Image above: The Progress resupply vehicle is an automated, unpiloted version of the Soyuz spacecraft that is used to bring supplies and fuel to the ISS. Image Credit: NASA.

Undocking from the ISS TGC held in October 27, 2014 at 8 o'clock 38 minutes Moscow time. After her Progress was in free flight, during which the space experiment was conducted "Reflection". During this time, experts studied the possibility of transmission of optical signals to study the modifications of the earth's atmosphere.

ROSCOSMOS Press Release: http://www.federalspace.ru/21129/

Images (mentioned), Text, Credits: Press Service of the Russian Federal Space Agency/ROSCOSMOS/Translation: Orbiter.ch Aerospace.

Greetings, Orbiter.ch

Rosetta continues into its full science phase

ESA - Rosetta Mission patch.

20 November 2014

With the Philae lander’s mission complete, Rosetta will now continue its own extraordinary exploration, orbiting Comet 67P/Churymov–Gerasimenko during the coming year as the enigmatic body arcs ever closer to our Sun.

Last week, ESA’s Rosetta spacecraft delivered its Philae lander to the surface of the comet for a dramatic touchdown.

The lander’s planned mission ended after about 64 hours when its batteries ran out, but not before it delivered a full set of results that are now being analysed by scientists across Europe.

Rosetta spacecraft

Rosetta’s own mission is far from over and the spacecraft remains in excellent condition, with all of its systems and instruments performing as expected.

“With lander delivery complete, Rosetta will resume routine science observations and we will transition to the ‘comet escort phase’,” says Flight Director Andrea Accomazzo.

“This science-gathering phase will take us into next year as we go with the comet towards the Sun, passing perihelion, or closest approach, on 13 August, at 186 million kilometres from our star.”

On 16 November, the flight control team moved from the large Main Control Room at ESA’s Space Operations Centre in Darmstadt, Germany, where critical operations during landing were performed, to a smaller Dedicated Control Room, from where the team normally flies the craft.

Rosetta control room

Since then, Rosetta has performed a series of manoeuvres, using its thrusters to begin optimising its orbit around the comet for the 11 scientific instruments.

“Additional burns planned for today, 22 and 26 November will further adjust the orbit to bring it up to about 30 km above the comet,” says Sylvain Lodiot, Spacecraft Operations Manager.

From next week, Rosetta’s orbit will be selected and planned based on the needs of the scientific sensors. After arrival on 6 August, the orbit was designed to meet the lander’s needs.

Getting as close as feasible

On 3 December, the craft will move down to height of 20 km for about 10 days, after which it will return to 30 km.

With the landing performed, all future trajectories are designed purely with science as the driver, explained Laurence O’Rourke and Michael Küppers at the Rosetta Science Operations Centre near Madrid, Spain.

“The desire is to place the spacecraft as close as feasible to the comet before the activity becomes too high to maintain closed orbits,” says Laurence.

Rosetta path after 12 November

“This 20 km orbit will be used by the science teams to map large parts of the nucleus at high resolution and to collect gas, dust and plasma at increasing activity.”

Planning the science orbits involves two different trajectories: ‘preferred’ and ‘high-activity’. While the intention is always to fly the preferred path, Rosetta will move to the high-activity trajectory in the event the comet becomes too active as it heats up.

“This will allow science operations to continue besides the initial impact on science planning that such a move would entail,” adds Michael.

Science takes a front seat

“Science will now take front seat in this great mission. It’s why we are there in the first place!” says Matt Taylor, Rosetta Project Scientist.

“The science teams have been working intensively over the last number of years with the science operations centre to prepare the dual planning for this phase.”

When solar heat activates the frozen gases on and below the surface, outflowing gas and dust particles will create an atmosphere around the nucleus, known as the coma.

First spacecraft to track a comet toward the Sun

Rosetta will become the first spacecraft to witness at close quarters the development of a comet’s coma and the subsequent tail streaming for millions of kilometres into space. Rosetta will then have to stay further from the comet to avoid the coma affecting its orbit.

In addition, as the comet nears the Sun, illumination on its surface is expected to increase. This may provide sufficient sunlight for the DLR-operated Philae lander, now in hibernation, to reactivate, although this is far from certain.

Early next year, Rosetta will be switched into a mode that allows it to listen periodically for beacon signals from the surface.

Rosetta orbiting the comet

More about Rosetta

Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander is provided by a consortium led by DLR, MPS, CNES and ASI.

Regular updates on Rosetta’s continuing mission and its scientific explorations will be posted in the mission blog, via http://blogs.esa.int/rosetta.

For more information about Rosetta mission, visit: http://www.esa.int/Our_Activities/Space_Science/Rosetta

Related links:

Rosetta overview: http://www.esa.int/Our_Activities/Space_Science/Rosetta_overview

Rosetta factsheet: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Rosetta_factsheet

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Rosetta/Frequently_asked_questions

Rosetta  Operations: http://www.esa.int/Our_Activities/Operations

Images, video, Text, Credits: ESA / J. Huart.

Best regards, Orbiter.ch

NASA's Swift Mission Probes an Exotic Object: ‘Kicked’ Black Hole or Mega Star?

NASA - SWIFT Mission patch.

November 19, 2014

An international team of researchers analyzing decades of observations from many facilities, including NASA's Swift satellite, has discovered an unusual source of light in a galaxy some 90 million light-years away.

The object's curious properties make it a good match for a supermassive black hole ejected from its home galaxy after merging with another giant black hole. But astronomers can't yet rule out an alternative possibility. The source, called SDSS1133, may be the remnant of a massive star that erupted for a record period of time before destroying itself in a supernova explosion.

Swift Probes Exotic Object: 'Kicked' Black Hole or Mega Star?

Video above: Zoom into Markarian 177 and SDSS1133 and see how they compare with a simulated galaxy collision. When the central black holes in these galaxies combine, a "kick" launches the merged black hole on a wide orbit taking it far from the galaxy's core. Video Credit: NASA Goddard's Scientific Visualization Studio.

"With the data we have in hand, we can't yet distinguish between these two scenarios," said lead researcher Michael Koss, an astronomer at ETH Zurich, the Swiss Federal Institute of Technology. "One exciting discovery made with NASA's Swift is that the brightness of SDSS1133 has changed little in optical or ultraviolet light for a decade, which is not something typically seen in a young supernova remnant."

In a study published in the Nov. 21 edition of Monthly Notices of the Royal Astronomical Society, Koss and his colleagues report that the source has brightened significantly in visible light during the past six months, a trend that, if maintained, would bolster the black hole interpretation. To analyze the object in greater detail, the team is planning ultraviolet observations with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope in October 2015.

Image above: The dwarf galaxy Markarian 177 (center) and its unusual source SDSS1133 (blue) lie 90 million light-years away. The galaxies are located in the bowl of the Big Dipper, a well-known star pattern in the constellation Ursa Major. Image Credit: Sloan Digital Sky Survey.

Whatever SDSS1133 is, it's persistent. The team was able to detect it in astronomical surveys dating back more than 60 years.

The mystery object is part of the dwarf galaxy Markarian 177, located in the bowl of the Big Dipper, a well-known star pattern within the constellation Ursa Major. Although supermassive black holes usually occupy galactic centers, SDSS1133 is located at least 2,600 light-years from its host galaxy's core.

In June 2013, the researchers obtained high-resolution near-infrared images of the object using the 10-meter Keck II telescope at the W. M. Keck Observatory in Hawaii. They reveal the emitting region of SDSS1133 is less than 40 light-years across and that the center of Markarian 177 shows evidence of intense star formation and other features indicating a recent disturbance. 

"We suspect we're seeing the aftermath of a merger of two small galaxies and their central black holes," said co-author Laura Blecha, an Einstein Fellow in the University of Maryland's Department of Astronomy and a leading theorist in simulating recoils, or "kicks," in merging black holes. "Astronomers searching for recoiling black holes have been unable to confirm a detection, so finding even one of these sources would be a major discovery."

Image above: Using the Keck II telescope in Hawaii, researchers obtained high-resolution images of Markarian 177 and SDSS1133 using a near-infrared filter. Twin bright spots in the galaxy's center are consistent with recent star formation, a disturbance that hints this galaxy may have merged with another. Image Credit: Credit: W. M. Keck Observatory/M. Koss (ETH Zurich) et al.

The collision and merger of two galaxies disrupts their shapes and results in new episodes of star formation. If each galaxy possesses a central supermassive black hole, they will form a bound binary pair at the center of the merged galaxy before ultimately coalescing themselves.

Merging black holes release a large amount of energy in the form of gravitational radiation, a consequence of Einstein's theory of gravity. Waves in the fabric of space-time ripple outward in all directions from accelerating masses. If both black holes have equal masses and spins, their merger emits gravitational waves uniformly in all directions. More likely, the black hole masses and spins will be different, leading to lopsided gravitational wave emission that launches the black hole in the opposite direction.

The kick may be strong enough to hurl the black hole entirely out of its home galaxy, fating it to forever drift through intergalactic space. More typically, a kick will send the object into an elongated orbit. Despite its relocation, the ejected black hole will retain any hot gas trapped around it and continue to shine as it moves along its new path until all of the gas is consumed.

Animation above: SDSS1133 (bright spot, lower left) has been a persistent source for more than 60 years. This sequence of archival astronomical imagery, taken through different instruments and filters, shows that the source is detectable in 1950 and brightest in 2001. Image Credit: NASA's Goddard Space Flight Center/M. Koss (ETH Zurich).

If SDSS1133 isn't a black hole, then it might have been a very unusual type of star known as a Luminous Blue Variable (LBV). These massive stars undergo episodic eruptions that cast large amounts of mass into space long before they explode. Interpreted in this way, SDSS1133 would represent the longest period of LBV eruptions ever observed, followed by a terminal supernova explosion whose light reached Earth in 2001.

The nearest comparison in our galaxy is the massive binary system Eta Carinae, which includes an LBV containing about 90 times the sun's mass. Between 1838 and 1845, the system underwent an outburst that ejected at least 10 solar masses and made it the second-brightest star in the sky. It then followed up with a smaller eruption in the 1890s.

In this alternative scenario, SDSS1133 must have been in nearly continual eruption from at least 1950 to 2001, when it reached peak brightness and went supernova. The spatial resolution and sensitivity of telescopes prior to 1950 were insufficient to detect the source. But if this was an LBV eruption, the current record shows it to be the longest and most persistent one ever observed. An interaction between the ejected gas and the explosion's blast wave could explain the object's steady brightness in the ultraviolet.

Whether it's a rogue supermassive black hole or the closing act of a rare star, it seems astronomers have never seen the likes of SDSS1133 before.

Related Links:

Download HD video and print-resolution images from NASA Goddard's Scientific Visualization Studio:
http://svs.gsfc.nasa.gov/goto?10082

Paper: "SDSS1133: an unusually persistent transient in a nearby dwarf galaxy":
http://mnras.oxfordjournals.org/content/445/1/515

Simulations Uncover 'Flashy' Secrets of Merging Black Holes (09.27.12):
http://www.nasa.gov/topics/universe/features/black-hole-secrets.html

Giant Black Hole Kicked Out of Home Galaxy (06.04.2012):
http://www.nasa.gov/mission_pages/chandra/news/H-12-182.html

For more information about SWIFT mission, visit: http://swift.gsfc.nasa.gov/ and http://www.nasa.gov/mission_pages/swift/main/

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Francis Reddy.

Best regards, Orbiter.ch

LHCb observes two new baryon particles

CERN - European Organization for Nuclear Research logo.

November 19, 2014

Today the collaboration for the LHCb experiment at CERN’s Large Hadron Collider announced the discovery of two new particles in the baryon family. The particles, known as the Xi_b'^- and Xi_b*^-, were predicted to exist by the quark model but had never been seen before. A related particle, the Xi_b*⁰, was found by the CMS experiment at CERN in 2012. The LHCb collaboration submitted a paper reporting the finding to Physical Review Letters.

Like the well-known protons that the LHC accelerates, the new particles are baryons made from three quarks bound together by the strong force. The types of quarks are different, though: the new X_ib particles both contain one beauty (b), one strange (s), and one down (d) quark. Thanks to the heavyweight b quarks, they are more than six times as massive as the proton. But the particles are more than just the sum of their parts: their mass also depends on how they are configured. Each of the quarks has an attribute called "spin". In the Xi_b'^- state, the spins of the two lighter quarks point in opposite directions, whereas in the Xi_b*^- state they are aligned. This difference makes the Xi_b*^- a little heavier.

“Nature was kind and gave us two particles for the price of one," said Matthew Charles of the CNRS's LPNHE laboratory at Paris VI University. "The Xi_b'^- is very close in mass to the sum of its decay products: if it had been just a little lighter, we wouldn't have seen it at all using the decay signature that we were looking for.”

"This is a very exciting result. Thanks to LHCb's excellent hadron identification, which is unique among the LHC experiments, we were able to separate a very clean and strong signal from the background," said Steven Blusk from Syracuse University in New York. “It demonstrates once again the sensitivity and how precise the LHCb detector is.”

CERN’s Large Hadron Collider (LHC)

As well as the masses of these particles, the research team studied their relative production rates, their widths – a measure of how unstable they are – and other details of their decays. The results match up with predictions based on the theory of Quantum Chromodynamics (QCD).

QCD is part of the Standard Model of particle physics, the theory that describes the fundamental particles of matter, how they interact and the forces between them. Testing QCD at high precision is a key to refine our understanding of quark dynamics, models of which are tremendously difficult to calculate.

“If we want to find new physics beyond the Standard Model, we need first to have a sharp picture,” said LHCb’s physics coordinator Patrick Koppenburg from Nikhef Institute in Amsterdam. “Such high precision studies will help us to differentiate between Standard Model effects and anything new or unexpected in the future.”

The measurements were made with the data taken at the LHC during 2011-2012. The LHC is currently being prepared – after its first long shutdown – to operate at higher energies and with more intense beams. It is scheduled to restart by spring 2015.

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 20 Member States.

Further information:

Read the paper on Arxiv (link is external): http://arxiv.org/abs/1411.4849

LHCb collaboration website: http://lhcb-public.web.cern.ch/lhcb-public/Welcome.html#StrBeaBa

CMS collaboration website: http://cms.web.cern.ch/news/observation-new-xib0-beauty-particle

Related links:

LHCb experiment: http://home.web.cern.ch/about/experiments/lhcb

LHC - Large Hadron Collider: http://home.web.cern.ch/topics/large-hadron-collider

Image, Text, Credits: CERN/Cian O'Luanaigh.

Greetings, Orbiter.ch

Second Time Through, Mars Rover Examines Chosen Rocks

NASA - Mars Science Laboratory (MSL) logo.

November 19, 2014

Image above: This small ridge, about 3 feet (1 meter) long, appears to resist wind erosion more than the flatter plates around it. Image Credit: NASA/JPL-Caltech/MSSS.

NASA's Curiosity Mars rover has completed a reconnaissance "walkabout" of the first outcrop it reached at the base of the mission's destination mountain and has begun a second pass examining selected rocks in the outcrop in more detail.

Exposed layers on the lower portion of Mount Sharp are expected to hold evidence about dramatic changes in the environmental evolution of Mars. That was a major reason NASA chose this area of Mars for this mission. The lowermost of these slices of time ascending the mountain includes a pale outcrop called "Pahrump Hills." It bears layers of diverse textures that the mission has been studying since Curiosity acquired a drilled sample from the outcrop in September.

In its first pass up this outcrop, Curiosity drove about 360 feet (110 meters), and scouted sites ranging about 30 feet (9 meters) in elevation. It evaluated potential study targets from a distance with mast-mounted cameras and a laser-firing spectrometer.

Image above: This patch of Martian bedrock, about 2 feet (70 centimeters) across, is finely layered rock with some pea-size inclusions. Image Credit: NASA/JPL-Caltech/MSSS.

"We see a diversity of textures in this outcrop -- some parts finely layered and fine-grained, others more blocky with erosion-resistant ledges," said Curiosity Deputy Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory, Pasadena, California. "Overlaid on that structure are compositional variations. Some of those variations were detected with our spectrometer. Others show themselves as apparent differences in cementation or as mineral veins. There's a lot to study here."

During a second pass up the outrcrop, the mission is using a close-up camera and spectrometer on the rover's arm to examine selected targets in more detail. The second-pass findings will feed into decisions about whether to drill into some target rocks during a third pass, to collect sample material for onboard laboratory analysis.

"The variations we've seen so far tell us that the environment was changing over time, both as the sediments were laid down and also after they hardened into bedrock," Vasavada said. "We have selected targets that we think give us the best chance of answering questions about how the sediments were deposited -- in standing water? flowing water? sand blowing in the wind? -- and about the composition during deposition and later changes."

Image above: A wheel track cuts through a windblown ripple of dusty sand in this Nov. 7, 2014, image from the Mastcam on NASA's Curiosity rover. The view spans about four feet across. Image Credit: NASA/JPL-Caltech/MSSS.

The first target in the second pass is called "Pelona," a fine-grained, finely layered rock close to the September drilling target at the base of Pahrump Hills outcrop. The second is a more erosion-resistant ledge called "Pink Cliffs."

Before examining Pelona, researchers used Curiosity's wheels as a tool to expose a cross section of a nearby windblown ripple of dust and sand. One motive for this experiment was to learn why some ripples that Curiosity drove into earlier this year were more difficult to cross than anticipated.

While using the rover to investigate targets in Pahrump Hills, the rover team is also developing a work-around for possible loss of use of a device used for focusing the telescope on Curiosity's Chemistry and Camera (ChemCam) instrument, the laser-firing spectrometer.

Diagnostic data from ChemCam suggest weakening of the instrument's smaller laser. This is a continuous wave laser used for focusing the telescope before the more powerful laser is fired. The main laser induces a spark on the target it hits; light from the spark is received though the telescope and analyzed with spectrometers to identify chemical elements in the target. If the smaller laser has become too weak to continue using, the ChemCam team plans to test an alternative method: firing a few shots from the main laser while focusing the telescope, before performing the analysis. This would take advantage of more than 2,000 autofocus sequences ChemCam has completed on Mars, providing calibration points for the new procedure.

Image above: This northeast-facing view from the lower edge of the pale "Pahrump Hills" outcrop at the base of Mount Sharp includes wind-sculpted ripples of sand and dust in the middle ground. It was taken by Curiosity's Navcam on Nov. 13, 2014. Image Credit: NASA/JPL-Caltech/MSSS.

Curiosity landed on Mars in August 2012, but before beginning the drive toward Mount Sharp, the rover spent much of the mission's first year productively studying an area much closer to the landing site, but in the opposite direction. The mission accomplished its science goals in that Yellowknife Bay area. Analysis of drilled rocks there disclosed an ancient lakebed environment that, more than three billion years ago, offered ingredients and a chemical energy gradient favorable for microbes, if any existed there.

Curiosity spent its second year driving more than 5 miles (8 kilometers) from Yellowknife Bay to the base of Mount Sharp, with pauses at a few science waypoints.

NASA's Mars Science Laboratory Project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions. JPL, a division of the California Institute of Technology in Pasadena, built the rover and manages the project for NASA's Science Mission Directorate in Washington.

For more information about Curiosity, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/

You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity

Images (mentioned), Text, Credits: NASA/JPL/Guy Webster.

Cheers, Orbiter.ch

Spooky Alignment of Quasars Across Billions of Light-years

ESO - European Southern Observatory logo.

19 November 2014

VLT reveals alignments between supermassive black hole axes and large-scale structure

Artist’s impression of mysterious alignment of quasar rotation axes

New observations with ESO’s Very Large Telescope (VLT) in Chile have revealed alignments over the largest structures ever discovered in the Universe. A European research team has found that the rotation axes of the central supermassive black holes in a sample of quasars are parallel to each other over distances of billions of light-years. The team has also found that the rotation axes of these quasars tend to be aligned with the vast structures in the cosmic web in which they reside.

Quasars are galaxies with very active supermassive black holes at their centres. These black holes are surrounded by spinning discs of extremely hot material that is often spewed out in long jets along their axes of rotation. Quasars can shine more brightly than all the stars in the rest of their host galaxies put together.

A team led by Damien Hutsemékers from the University of Liège in Belgium used the FORS instrument on the VLT to study 93 quasars that were known to form huge groupings spread over billions of light-years, seen at a time when the Universe was about one third of its current age.

Simulation of large scale structure

“The first odd thing we noticed was that some of the quasars’ rotation axes were aligned with each other — despite the fact that these quasars are separated by billions of light-years,” said Hutsemékers.

The team then went further and looked to see if the rotation axes were linked, not just to each other, but also to the structure of the Universe on large scales at that time.

When astronomers look at the distribution of galaxies on scales of billions of light-years they find that they are not evenly distributed. They form a cosmic web of filaments and clumps around huge voids where galaxies are scarce. This intriguing and beautiful arrangement of material is known as large-scale structure.

The new VLT results indicate that the rotation axes of the quasars tend to be parallel to the large-scale structures in which they find themselves. So, if the quasars are in a long filament then the spins of the central black holes will point along the filament. The researchers estimate that the probability that these alignments are simply the result of chance is less than 1%.

Artist's impression of mysterious alignment of quasar rotation axes

“A correlation between the orientation of quasars and the structure they belong to is an important prediction of numerical models of evolution of our Universe. Our data provide the first observational confirmation of this effect, on scales much larger that what had been observed to date for normal galaxies,” adds Dominique Sluse of the Argelander-Institut für Astronomie in Bonn, Germany and University of Liège.

The team could not see the rotation axes or the jets of the quasars directly. Instead they measured the polarisation of the light from each quasar and, for 19 of them, found a significantly polarised signal. The direction of this polarisation, combined with other information, could be used to deduce the angle of the accretion disc and hence the direction of the spin axis of the quasar.

“The alignments in the new data, on scales even bigger than current predictions from simulations, may be a hint that there is a missing ingredient in our current models of the cosmos,” concludes Dominique Sluse.

More information:
This research was presented in a paper entitled “Alignment of quasar polarizations with large-scale structures“, by D. Hutsemékers et al., to appear in the journal Astronomy & Astrophysics on 19 November 2014.

The team is composed of D. Hutsemékers (Institut d’Astrophysique et de Géophysique, Université de Liège, Liège, Belgium), L. Braibant (Liège), V. Pelgrims (Liège) and D. Sluse (Argelander-Institut für Astronomie, Bonn, Germany; Liège).

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Links:

Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1438/eso1438a.pdf

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

Images, Text, Credits: ESO/M. Kornmesser/Illustris Collaboration/Video: ESO/M. Kornmesser.

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