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Dead Star And Distant Black Holes Dazzle In X-Rays

January 10, 2014 Leave a comment

Image credit: NASA/JPL-Caltech/McGill

Image credit: NASA/JPL-Caltech/McGill

Two new views from NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, showcase the telescope’s talent for spying objects near and far. One image shows the energized remains of a dead star, a structure nicknamed the “Hand of God” after its resemblance to a hand. Another image shows distant black holes buried in blankets of dust.

“NuSTAR’s unique viewpoint, in seeing the highest-energy X-rays, is showing us well-studied objects and regions in a whole new light,” said Fiona Harrison, the mission’s principal investigator at the California Institute of Technology in Pasadena, Calif.

NuSTAR launched into space June 13, 2012, on a mission to explore the high-energy X-ray universe. It is observing black holes, dead and exploded stars and other extreme objects in our own Milky Way galaxy and beyond.

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A Galaxy With Two Hearts

January 10, 2014 Leave a comment

Messier 83. Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

Messier 83. Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)

This new Hubble image shows the spiral galaxy Messier 83, otherwise known as the Southern Pinwheel Galaxy. One of the largest and closest barred spirals to us, this galaxy is dramatic and mysterious; it has hosted a large number of supernova explosions, and is thought to have a double nucleus lurking at its core.

Messier 83 is not one to blend into the background. Located some 15 million light-years away in the constellation of Hydra (The Sea Serpent), it is one of the most conspicuous galaxies of its type in our skies. It is a prominent member of a group of galaxies known as the Centaurus A/M83 Group, which also counts dusty Centaurus A (heic1110) and irregular NGC 5253 (potw1248a) as members.

Spiral galaxies come in a range of types depending on their appearance and structure — for example, how tightly wound their arms are, and the characteristics of the central bulge. Messier 83 has a “bar” of stars slicing through its centre, leading to its classification as a barred spiral. The Milky Way also belongs to this category.

These bars are thought to act a bit like a funnel, channelling gas inwards towards the galaxy’s centre. This gas is then used to form new stars and also to feed the galaxy’s central black hole, explaining why many barred spirals — including Messier 83 — have very active and luminous central regions.

However, Messier 83’s centre is mysterious and unusual; the supermassive black hole at its heart is not alone.

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First Detailed Look At A Normal Galaxy In The Very Early Universe

January 10, 2014 Leave a comment

University of Hawaii at Manoa astronomer Regina Jorgenson has obtained the first image that shows the structure of a normal galaxy in the early universe as captured by the W. M. Keck Observatory. The results were presented at the winter American Astronomical Society meeting being held this week near Washington, DC.

The galaxy, called DLA2222-0946, is so faint that it is virtually invisible at all but a few specific wavelengths. It is a member of a class of galaxies thought to be the progenitors of spiral galaxies like our own Milky Way.

These galaxies are known to contain most of the neutral gas that is the fuel for star formation, so they are an important tool for understanding star and galaxy formation and evolution. Discovered and classified over 30 years ago, they have been notoriously difficult to see directly.

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Unraveling The Web Of A Cosmic Creepy-Crawly

January 10, 2014 Leave a comment

Image credit: NASA, ESA, E. Sabbi (STScI)

Image credit: NASA, ESA, E. Sabbi (STScI)

This new Hubble image is the best-ever view of a cosmic creepy-crawly known as the Tarantula Nebula, a region full of star clusters, glowing gas, and dark dust. Astronomers are exploring and mapping this nebula as part of the Hubble Tarantula Treasury Project, in a bid to try to understand its starry anatomy.

The Tarantula Nebula is located in one of our closest galactic neighbours, the Large Magellanic Cloud. Hubble has released images of this celestial spider several times before: in 2004 (heic0416), 2010 (heic1008), 2011 (heic1105) and 2012 (heic1206). While these images show striking panoramic views of this turbulent region, this new image gives us the deepest and most detailed view yet.

Created using observations taken as part of the Hubble Tarantula Treasury Project (HTTP), this image is composed of near-infrared observations from both Hubble’s Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS). Due to the combination of infrared filters in this image a purple haze fills the frame, with deep red wisps of dust and bright stars scattered throughout.

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One-Percent Measure Of The Universe Constrains Dark Energy

January 10, 2014 Leave a comment

At the January AAS meeting, researchers from the Baryon Oscillation Spectroscopic Survey (BOSS) announced that they have measured the distance to galaxies more than six billion light years away to an accuracy of one percent. Together with information on the rate at which the Universe was expanding, these measurements allow the scientists at the Max Planck Institute for Extraterrestrial Physics to place powerful constraints on the properties of the mysterious Dark Energy. This component is thought to be responsible for the current accelerated expansion of the Universe.

The new distance measurements were presented at the meeting of the American Astronomical Society by Harvard University astronomer Daniel Eisenstein, the director of SDSS-III. They are detailed in a series of articles submitted by the BOSS collaboration last month and available online. “Determining distance is a fundamental challenge of observational astronomy,” said Eisenstein. “You see something in the sky — how far away is it?”

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