It could even help us comprehend the origin and distribution of dark matter, write three scientists currently preparing for the GLAST mission from NASA’s Goddard Space Flight Centre in Greenbelt, Maryland, USA, in this month’s Physics World.
The Gamma-Ray Large Area Space Telescope (GLAST), to be launched on 16 May 2008, is a four-tonne observatory packed with state-of-the-art particle detectors that will study the gamma-ray sky in unprecedented detail.
Gamma rays are a form of electromagnetic radiation with much higher frequency and energy than visible light, UV light or even X-rays. Having such high energy, gamma rays are hard to collect and focus in the way that a conventional telescope does with visible light. Gamma rays are therefore the most difficult form of electromagnetic radiation to track in space.
Whereas visible light reveals thousands of stars and individual planets moving slowly across the sky, studying the skies at gamma-ray frequencies reveals a much weirder picture of space.
Gamma rays are not produced by hot, glowing objects, but from collisions between charged, very rapidly moving, particles and matter or light. The high frequency photons that are emitted from these collisions provide a glimpse of the most extreme astrophysical processes known.
Black holes, for example, accelerate matter to produce extreme energies in active galaxies. The gamma rays emitted in these scenarios have the equivalent energy to that of all the stars in an entire galaxy over all wavelengths.
Until now, however, existing ground-based gamma-ray detectors have not been sophisticated enough to measure these emissions in any detail over long periods. The astrophysicists cite looking for signatures of as-yet-unknown fundamental physical processes as a key reason for embarking on this project.
Julie McEnery, Steve Ritz and Neil Gehrels of NASA’s Goddard Space Centre, write, “We expect GLAST to have a large impact on many areas of astrophysics but what is most exciting are the surprises: with any luck, the greatest GLAST science has not even been thought of yet.”
Joseph Winters | alfa
A new force for optical tweezers awakens
19.06.2019 | University of Gothenburg
View of the Earth in front of the Sun
19.06.2019 | Georg-August-Universität Göttingen
The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.
Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...
The well-known representation of chemical elements is just one example of how objects can be arranged and classified
The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...
Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.
Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...
Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.
The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...
Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.
The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
19.06.2019 | Physics and Astronomy
19.06.2019 | Information Technology
19.06.2019 | Materials Sciences