A galaxy is born

January 29, 2012 • 6:36 am

From the website Starts with a Bang, we have a lovely video (based on computer simulations) depicting the formation of a galaxy similar to ours beginning at the Big Bang and evolving up to the present (“Gyrs” on the lower right represent the passage of billions of years).

(Video credit: Fabio Governato et al./U. of Washington/NASA Advanced Supercomputing.)

Mergers of galaxies are common in their evolution. This movie shows the evolution of a galaxy with similar mass to our own Milky Way, commencing shortly after the Big Bang. The simulation is in a fully cosmological setting, according to our knowledge of Big Bang cosmology. This particular galaxy has a rich merging history, including a major merger at redshift of ~1, i.e. at a time when the Universe was almost half its current age. A large disk reforms from gas left over after the merger, and from subsequent gaseous accretion.

I’d be remiss if I didn’t add that Ethan Siegel, creator of Starts with a Bang, presents this simulation to tout a worthy project: The Charity Engine, in which you can donate some of your own computer’s time to help perform scientific calculations like those involved in the galaxy simulation—and help good charities at the same time.

h/t: Michael

11 thoughts on “A galaxy is born

  1. I assume that video isn’t showing the Dark Matter. I would enjoy seeing a sim that would give me some idea of how DM is distributed in relation to the 3% [?] of normal ‘stuff’ during galaxy formation.

    All the same a very cool simulation that deserves a waltz accompaniment. It all looks very protean & ‘spermy’ ~ as if imaged from a microscope

    1. I think it is with DM, see my more detailed comment #4.

      The Eris simulation I link there is much the same froth and dynamical evolution, only the Milky Way type spiral structure comes out better. (They have the size right too.)

      And the music is well picked!

  2. These projects are very worth while, I run the one for Stanford’s Folding@home myself.

    As a non-scientist I cannot make any contributions to science myself, so I am glad I have this way of helping.

  3. I love how it shows the galaxy formation and trajectories along the dark matter filaments that the gas clouds adhere to.

    [Note to Michael Fisher: Its youtube page claims “a fully cosmological setting” so it has to include DM.

    Baryon matter gas clouds are mostly interspersed within dark matter aggregations for gravity reasons AFAIK. It is when dynamical processes such as galaxy collisions or gas jets occur that they strip or inject gas from ‘DM only’ regions. I don’t know how extensive such volumes are.]

    The real beaut IMHO is the recent Eris simulation. It was the first time a spiral galaxy was faithfully modeled, and the necessary component was DM. Recommended to watch for sheer awesome beauty.

    That simulation removed the last “alternative gravity” formed hole of some pathological science circles, that of predicting mass curves of galaxies better than standard cosmological structure formation models.

    To paraphrase Dobzhansky:

    – Nothing in Cosmology Makes Sense Except in the Light of Dark Matter.

  4. Question for those who use charityengine.

    I have lots of tasks that are “ready to report” under the status column, what do you have to do then. I see no visible way to send those completed tasks.

  5. I am glad to know, that WE are only local !
    Does not matter,your creed,colour,sex,race,nothing.We are LOCAL.

    I will keep with my Greeks,and remember, all that is known, is nothing, to what is KNOWN by THE Gods !!

    Keep well,keep safe.

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