TOLL FREE CERN Courier November 2015 1800 4250 433 CIN: L32309KA1954GO1000787 Sciencewatch C OMPILED BY J OHN S WAIN , N ORTHEASTERN U NIVERSITY BEL, an integral part of the Ocean on Enceladus Big Bang experiment Enceladus, one of Saturn’s (62!) moons, has a global sub-surface ocean. Using pictures from the Cassini probe, P C Thomas of Cornell University and colleagues observed the object’s libration and found it so large as to imply a global ocean. Liquid water and vapour had been seen in jets from a south-polar depression, but the new work rules out a localised polar sea. Salts and organic material have been detected in the jets, so this now looks like an interesting place to search for life. ● Weblink dx.doi.org/10.1016/j.icarus.2015.08.037 Saturn’s moon Enceladus. (Image credit: NASA/JPL/Space Science Institute.) Photonic molecules quantum mechanics, time is a global Artifi cial leaf parameter, but in general relativity it is Two photons can form a Coulomb bound local proper time that matters, this opens state. This sounds, of course, ridiculous, An artifi cial “leaf” can make fuels from carbon new avenues to understanding the interplay dioxide, and possibly compete with solar cells, photo by [email protected] because photons are uncharged, but between quantum mechanics and gravity. M F Maghrebi of NIST/University of capturing energy in the form of combustible Maryland and colleagues took advantage of chemicals instead of electricity. Eva M Nichols ● Further reading the photon coupling to Rydberg states via of the University of California in Berkeley and Y Margalit et al. 2015 Science 349 1205. electromagnetically induced transparency, colleagues use a scheme coupling photoactive which provides an effective Coulomb inorganic materials such as platinum, or X-ray laser potential, at least in theory. Such bound α-NiS, to release hydrogen from water. The states could provide a means to couple to hydrogen is used, together with carbon dioxide, A stable atomic narrow-band X-ray laser has quantum information storied in photons by micro-organisms, which produce methane reached the shortest wavelength ever: 1.5 Å, for quantum computing, and it should be with a Faradaic effi ciency as high as 86%. and about 10 times shorter than had been possible to couple arbitrarily many photons The basic scheme could be generalised to use previously achieved. in this way. sunlight to synthesize more complex chemical Hitoki Yoneda of the University of products. Electro-Communications in Tokyo and the ● Further reading RIKEN SPring-8 Center in Hyogo, Japan, Solid State silicon detectors from BEL M F Maghrebi et al. 2015 Phys. Rev. Lett. 115 123601. ● Further reading and colleagues used a photoionisation- E M Nichols et al. 2015 Proc. Nat. Acad. Sci. 112 pumping scheme proposed back in 1967, 11461. Bharat Electronics Ltd (BEL), India’s leading Defence electronics company, has The farthest galaxy where an X-ray photon from a pump developed state-of-the-art solid\state silicon detectors for the CMS experiment at pulse removes an inner shell 1s electron CERN, Geneva. The most distant galaxy yet observed is Self-interfering clock from a copper atom, effectively making at z = 8.68, or more than 13.2 billion years it an excited medium in which amplifi ed BEL’s initiative started with the development of large area silicon sensors to be old, dating just 600 million years from Interference experiments give us much of spontaneous emission (ASE) can occur, used in the pre-shower detector of the CMS experiment in 1999. Since then, BEL Bharat Electronics Limited the start of our universe. Adi Zitran of our information about fundamental physics, with photons emitted from 2p electrons that has developed and manufactured silicon detectors of various sizes, geometries For more details please write to: Caltech and colleagues used the W M Keck and now they can be done with a new twist: fall to 1s.A second “seed” X-ray photon, and characteristics for applications such as position sensing, charge particle [email protected] Telescope in Mauna Kea, Hawaii, to self-interfering clocks. tuned to the correct wavelength, is then detection, gamma detection, photo-detection, X-ray detection, pocket dosimetry or call at 080-22195303/5539 discover the EGSY8p7 galaxy via its Lyman Ron Folman of Ben-Gurion University sent in to be amplifi ed. This is a proof of and spectroscopy. or fax: 080-28382322 alpha emissions, with a signifi cance of of the Negev in Beer-Sheva, Israel, principle, with a rather low (2%) effi ciency, about 7.5 standard deviations. Further and colleagues demonstrated the idea but wavelength stability, which could make BEL now offers a range of silicon detectors such as PIN Diodes, strip detectors, Marketing Components photo diode detectors, linear array photo diode detectors, quadrant detectors and spectroscopic studies could help our using Bose–Einstein condensates of this sort of laser competitive with X-ray Bharat Electronics Ltd (A Govt of India Enterprise) 87 double-sided strip detectors. Apart from these there are other detectors under understanding of early galaxy formation. about 10,000 Rb atoms prepared in free-electron lasers in the future. development such as Delta E-E detector, MOSFET detector and Silicon photo Jalahalli Post, Bengaluru - 560013 a superposition of two Zeeman states multiplier detector. These detectors are used in nuclear, medical & safety applications. www.bel-india.com ● Further reading as clocks. The clock time serves as a ● Further reading A Zitrin et al. 2015 Astrophys. J. Lett. 810 L12. “which-way” witness. Because in standard H Yoneda et al. 2015 Nature 524 446. 15 A Navratna Defence PSU CCOct15Ad_Bharat_FP.indd 1 07/10/2015 13:30 CERNCOURIER www. V OLUME 5 5 N UMBER 9 N OMBERV E 2 0 1 5 CERN Courier November 2015 KJLC® European Manufacturing is Expanding! Astrowatch C OMPILED BY M ARC TÜRLER , ISDC AND O BSERVATORY OF THE U NIVERSITY OF G ENEVA , AND CHIPP, U NIVERSITY OF Z URICH Massive black-hole pair is on fast-merger track Increased Earlier this year, astronomers discovered the observed quasi-sinusoidal signal in the Component Stock what appeared to be a pair of supermassive optical emission of the quasar should also black holes (SMBHs) circling towards a be seen in the ultraviolet (UV). Analysing collision, which would send out a burst of archival UV observations collected gravitational waves. A new study of the by NASA’s Hubble and GALEX space periodic signal from the quasar PG 1302-102 telescopes, D’Orazio and colleagues found seems to confi rm this interpretation by the same period with a 2–3 times higher Precision CNC showing that it could naturally arise due to amplitude. The stronger signal corresponds Machining relativistic Doppler boosting. precisely to the model expectations, by Black-hole binaries are expected to be taking into account the difference of spectral common in large elliptical galaxies, because slope measured from the optical to the UV. they most likely form by the merger of spiral Artist’s conception of a pair of super-massive By estimating the combined and relative galaxies, each hosting a central SMBH. A black holes, each surrounded by spiralling mass of the black holes in PG 1302-102, they way to fi nd binary systems in quasars is to gas forming an accretion disc. (Image credit: narrow down the predicted time until the search for a period signal repeating over P Marenfeld/NOAO/AURA/NSF.) black holes coalesce to between 20,000 and several years. This is quite challenging, 350,000 years from now, with a best estimate owing to the erratic variability of these 14 per cent every fi ve years, suggesting the of 100,000 years – a very long time for distant active galactic nuclei. Until recently, pair was less than a tenth of a light-year apart. humans but not in the life of stars and black only one rather peculiar object, called OJ287, In a new study, also published in Nature, holes. If confi rmed by more observations was clearly identifi ed as a double black-hole Daniel D’Orazio and his group at the in the years to come, this discovery and that system, with a smaller black hole plunging Columbia University interpret the sinusoidal of other binary black-hole candidates will twice through the extended accretion disc modulation as due to relativistic Doppler improve the chances of witnessing a merger of the primary black hole along its inclined, boosting. They fi nd that the signal is and the gravitational waves predicted, but not eccentric 12 year-long orbit. consistent with a model where most of the yet detected, by the theory of general relativity In January, a team led by Matthew optical emission comes from a smaller black laid down by Einstein 100 years ago. Graham, a computational astronomer at hole orbiting a heavier one at nearly a tenth the California Institute of Technology, of the speed of light. At that speed – via the ● Weblinks designed an algorithm to detect sinusoidal relativistic Doppler beaming effect – the www.nature.com/nature/journal/v525/n7569/full/ intensity variations from 247,000 quasars smaller black hole would appear to slightly nature15262.html monitored by optical telescopes in brighten as it approaches the Earth and fade www.nature.com/nature/journal/v518/n7537/full/ Arizona and Australia. Of the 20 pairs of as it moves away on its orbit. They note that nature14143.html black-hole candidates discovered, they hydrodynamical simulations do, indeed, www.eurekalert.org/pub_releases/2015-09/ focused on the most compelling bright suggest that the smaller black hole should be cu-nsf090915.php quasar – PG 1302-102.