Quasars are some of the brightest objects in the Universe, and astronomers believe they’re caused by the outpouring of radiation from the environment around an actively feeding supermassive black hole. New research using the Chandra X-Ray Observatory has looked inside a quasar, to see the disk of material spiraling into the black hole. Astronomers used the gravity from a relatively nearby galaxy as a gravitational lens to focus the light from the more distant quasar, giving this impressive view.
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There’s more dark matter than regular matter in the Universe, and they’re normally all mixed up together in galaxies. But astronomers using the Chandra X-Ray Observatory have found a situation where dark matter and normal matter can be wrenched apart. In a collision between giant galaxy clusters, hot gas clouds in the clusters encounter friction as they pass through one another, separating them from the stars. The dark matter isn’t affected by this friction either, so astronomers were able to calculate the effect of its gravity on regular matter.
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When a star flared briefly, astronomers knew it was because a dimmer star had passed directly in front, acting as a lens with its gravity to focus light. Unfortunately, they couldn’t find the star. This was important, because the brief microlensing event also turned up the fact that this lensing star has a planet. Astronomers have used the power of the Hubble Space Telescope to find this dim star two years after the lensing event. Identifying the star is critical, because it allows astronomers to measure its unique characteristics, such as mass, temperature and composition.
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Imagine looking at red houses, and sometimes you see a crow fly past. But every time you look at a blue house, there’s always a crow flying right in front of the house. The crow and the house could be miles apart, so this must be impossible, right? Well, according to a new survey if you look at a quasar, you’ll see a galaxy in front 25% of the time. But for gamma ray bursts, there’s almost always an intervening galaxy. Even though they could be separated by billions of light years. Figure that out. Dr. Jason X. Prochaska, from the University of California, Santa Cruz speaks to me about the strange results they’ve found, and what could be the cause.
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