Kategorie: Kosmologie

Flickering loops of plasma above the Sun’s churning surface have been captured in movies made by Japan’s Hinode spacecraft, providing a preview of what the probe will do once it begins its main phase of scientific observations. The spacecraft was launched by the Japan Aerospace Exploration Agency (JAXA) on 22 September 2006. JAXA is collaborating with NASA, ESA, and other organisations for the mission. Hinode’s three telescopes will make simultaneous observations in visible light, ultraviolet, and X-rays to help scientists understand the Sun’s ever-changing magnetic field. It is hoped that its observations will shed light on what triggers solar eruptions – so-called coronal mass ejections (CMEs). These ejections spew out radiation that poses a health risk for astronauts and they can also knock out satellites.

Development of loops of hot plasma above the Sun’s surface (15.9 MB; MPEG format)

Activity around a sunspot (8.5 MB; MPEG format)

A trio of space telescopes have combined to create a stunning image of the N49 supernova remnant in the Milky Way’s neighbouring galaxy, the Large Magellanic Cloud. The Spitzer Space Telescope imaged relatively cool gas toward the outer edge of the remnant in infrared, seen in red. The blue in the centre of the image, taken by the Chandra X-ray Observatory, indicates extremely hot gas. The Hubble Space Telescope is responsible for the optical view of white and yellow filaments.
https://chandra.harvard.edu/photo/2006/n49/

Astronomers using the H.E.S.S. telescopes have discovered the first ever modulated signal from space in Very High Energy Gamma Rays – the most energetic such signal ever observed. Regular signals from space have been known since the 1960s, when the first radio pulsar was discovered. This is the first time a signal has been seen at such high energies – 100.000 times higher than previously known – and is reported in the Journal „Astronomy and Astrophysics“.

https://www.mpi-hd.mpg.de/hfm/HESS/pages/press/old/PressRelease/LS5039Press-2006/PressRelease_E.html

ESA’s Integral space observatory has spotted a blast of gamma rays from a suspected black hole in the Milky Way. The outburst occurred on September 17, 2006, and gradually built in brightness over the course of a few days before declining again. It’s this rise and fall of brightness, called a light curve, that allowed astronomers identify the source as a black hole. It’s likely that a disk of gas and material orbiting the black hole became unstable, and a portion of it collapsed, creating the outburst.

Integral catches a new erupting black hole

The results, described in the article „IGJ 717497-2821: A new X-ray Nova“ by Roland Walter et al., appeared in „Astronomy and Astrophysics 461, L17-L20 (2007)“.
A free access online version can be found here.

New clues about the origins of cosmic rays, mysterious high-energy particles that bombard the Earth, have been revealed using NASA’s Chandra X-ray Observatory. An extraordinarily detailed image of the remains of an exploded star provides crucial insight into the generation of cosmic rays. For the first time, astronomers have mapped the rate of acceleration of cosmic ray electrons in a supernova remnant. The new map shows that the electrons are being accelerated at close to the theoretically maximum rate. This discovery provides compelling evidence that supernova remnants are key sites for energizing charged particles. The map was created from an image of Cassiopeia A, a 325-year-old remnant produced by the explosive death of a massive star. The blue, wispy arcs in the image trace the expanding outer shock wave where the acceleration takes place. The other colors in the image show debris from the explosion that has been heated to millions of degrees.
Chandra Discovers Relativistic Pinball Machine

The captivating appearance of an image of the starburst galaxy NGC 1313, taken with the FORS instrument at ESO’s Very Large Telescope, belies its inner turmoil. The dense clustering of bright stars and gas in its arms, a sign of an ongoing boom of star births, shows a mere glimpse of the rough times it has seen. Probing ever deeper into the heart of the galaxy, astronomers have revealed many enigmas that continue to defy our understanding.
The Topsy-Turvy Galaxy

Black holes bend our understanding of the Universe and laws of physics. But astronomers have discovered a black hole spinning so quickly, it breaks all the speed laws for rotation. The stellar mass black hole in question is known as GRS1915+105, and it’s spinning more than 950 times every second. As the black hole spins, it drags the surrounding space around with it, and gives astronomers an opportunity to study some of Einstein’s predictions about relativity.
Spinning Black Hole Pushes the Limit

U.S. astronomers using NASA’s Swift satellite have discovered a rare event: two supernovas side by side in one galaxy. The scientists say large galaxies typically play host to three supernovas per century, but Galaxy NGC 1316 has had two supernovas in fewer than five months – and a total of four supernovas in 26 years. That makes NGC 1316 – a massive elliptical galaxy about 80 million light-years from Earth – the most prodigious known producer of supernovas. Although NGC 1316 recently merged with a spiral galaxy, astronomers are quick to note all four supernovas in NGC 1316 appear to be of a variety previously not associated with galaxy mergers and massive star formation. Scientists are using the satellite to investigate whether the high supernova rate is a coincidence or a result of the merger.

http://science.psu.edu/news-and-events/2006-news/Swift11-2006.htm

Researchers at the University of California, Santa Cruz, have used NASA’s most powerful supercomputer to run the largest simulation to date of the formation and evolution of the dark matter halo that envelopes the Milky Way galaxy. Their results show substructures within the halo in unprecedented detail, providing a valuable tool for understanding the evolutionary history of our galaxy.
https://news.ucsc.edu/2006/11/977.html

Dark energy isn’t new. In fact, it’s been around for at least 9 billion years. According to new data gathered by the Hubble Space Telescope, this mysterious force was already working to speed up the expansion of the Universe when it was only a few billion years old. Hubble measured the light from 24 of the most distant supernovae ever seen, and found that the Universe is further apart than it should be if only gravity was around to slow things down.
Hubble Finds Evidence for Dark Energy in the Young Universe

https://www.nasa.gov/mission_pages/hubble/news/dark_energy.html