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Posts Tagged ‘Milky Way’

Realistic Simulation of the Formation of a Milky Way-Like Galaxy

August 31, 2011 1 comment

The first realistic simulation of a spiral galaxy similar to our own Milky Way has been generated by researchers at the University of California, Santa Cruz, and the Institute for Theoretical Physics in Zurich.

The simulation, called ERIS, took 1.4 million processor hours to complete. And that was on the 7th most powerful supercomputer in the world, NASA’s Pleiades supercomputer, which runs at 1.09 petaflops per second.

The simulation follows the formation of a galaxy equivalent to 7.9 × 1011 solar masses (1 solar mass is equal to the mass of our Sun) and has a total of 18.6 million particles.

The resulting galaxy has a radius of 2.5 kilo-parsecs (about 7.7 × 1016 kilometers). Previous attempts at simulating a realistic galaxy have failed, resulting in simulated galaxies which have too large of a central bulge. The finding of this study, which has been accepted for publication in Astrophysical Journal, found that,

A high star formation threshold appears therefore key in obtaining realistic late-type galaxies, as it enables the development of an inhomogeneous interstellar medium where star formation and heating by supernovae occur in a clustered fashion. The resulting outflows at high redshifts reduce the baryonic content of galaxies and preferentially remove low angular momentum gas, decreasing the mass of the bulge component.

Another important result of this work is that it supports the idea that cold dark matter constitutes a large portion of the mass in the universe.

Turning Boring Data Into Awesome Movies

January 21, 2011 Leave a comment

As reported today on Scientific American, the Advanced Visualization Laboratory at the National Center for Supercomputing Applications (NCSA), turn terabytes worth of data into majestic astronomic visual treats.

They talk more about the process in the Scientific American piece.  For me though, sometimes you just want to see the Universe in all its awesomeness, and leave the data analysis to the experts. (That last statement is a bit ironic since I am a data analyst, but that’s not important right now…)

The first mini-galaxies formed when the universe was just a few hundred million years old. Over time, these small galaxies interacted and merged to build up ever larger galaxies, including big spirals like our own Milky Way. Credit: NCSA/NASA/B. O’Shea (MSU) and M. Norman (UC San Diego)

Two spiral galaxies undergo a protracted crash lasting two billion years, eventually merging into a single elliptical galaxy. Credit: NCSA/NASA/B. Robertson (Caltech) and L. Hernquist (Harvard Univ.)

Beginning when the universe is about 20 million years old and continuing to the present day, this visualization provides a glimpse of how the cosmic web may have developed. Credit: NCSA/NASA/R. Cen and J. Ostriker, (Princeton Univ.)

You can see a few more videos like these at the James Webb Telescope page.

Umm…WTF is that?

January 11, 2011 Leave a comment

Image Credit: NASA, ESA, W. Keel (University of Alabama) and the Galaxy Zoo Team

What is that green blob in this photo?

It is called Hanney’s Voorwerp. Does that help? (It means Hanney’s Object in Dutch)

No? Ok, well it is a long stream of gas (about 300,000 light-years long, in fact) that is being illuminated by the Quasar being emitted from galaxy IC 2947.

A quasar is a bright stream of light that gets emitted from a black hole. Do you see the bright stream of light from the center of the galaxy? No?

That is because the quasar turned off about 200,000 years ago. The light from it is only now reaching the gas stream and illuminating it.

The image was taken by the Hubble Space Telescope around April 2010, and it has been a bit of a curiosity for a while. NASA has just released an explanation for what it is.

I could seriously do a blog made of entirely cool astronomy photos and it would always be interesting. Oh wait, there already is a site like that…damn.