APOD: The role for Resonance Rings in star formation

Posted: February 9, 2015 by tallbloke in Astronomy, Astrophysics
Tags: ,

H/T Oldbrew.

Golden rings of star formation

NGC 3081 is seen here nearly face-on. Compared to other spiral galaxies, it looks a little different. The galaxy’s barred spiral centre is surrounded by a bright loop known as a resonance ring. This ring is full of bright clusters and bursts of new star formation.

These rings form in particular locations known as resonances, where gravitational effects throughout a galaxy cause gas to pile up and accumulate in certain positions. These can be caused by the presence of a “bar” within the galaxy, as with NGC 3081, or by interactions with other nearby objects. It is not unusual for rings like this to be seen in barred galaxies, as the bars are very effective at gathering gas into these resonance regions, causing pile-ups which lead to active and very well-organised star formation.

Comments
  1. oldbrew says:

    It’s not just one resonance ring.

    ‘NGC 3081, an absolute magnitude MB = -20.0 early-type barred spiral having four well-defined resonance rings: a nuclear ring, an inner ring, an outer R1 ring, and an outer R pseudoring. Here we focus on a photometric study of the inner ring, a feature likely associated with an inner 4 : 1 resonance near the ends of the bar.’

    http://iopscience.iop.org/1538-3881/127/4/1982/fulltext/203365.text.html#rf20

  2. Doug Proctor says:

    The idea that there are more than 4 dimensions, but they are tiny, made me wonder if they could show up their presence at the galactic scale by distortions in shape, internal motion or structure that might be misinterpreted as measurement errors or uncertainties. Differences in apparent rotational xyzt values that don’t make sense at face value: a stable rotating object can’t have non-coherent elements. Essentially the local laws of physics appear different without the entirety disintegrating. Like seeing a warped torus from above and expecting it to be flat.

    If the forward direction of time and the expansion of space is a function of the “unfolding” of space-time, presently dominated by the initial Big Bang, local large, concentrated fusion events could create apparent distortions that take large volumes of our universe to average out. We might think the observation is from unseen “normal” matter or processes, or a reflection of observation limitations.

    Dark energy or dark matter strikes me as something like this, a cosmic Trenberth missing oceanic heat, only “missing” because conventional IPCC models require it to be present for the models to truly reflect climatological processes.

  3. oldbrew says:

    Doug P says: ‘Dark energy or dark matter strikes me as something like this, a cosmic Trenberth missing oceanic heat’

    AKA a fudge factor😉

    ‘A fudge factor is an ad hoc quantity introduced into a calculation, formula or model in order to make it fit observations or expectations. Examples include Einstein’s Cosmological Constant, dark energy, dark matter and inflation.’

    http://en.wikipedia.org/wiki/Fudge_factor

  4. Doug Proctor says:

    Thanks.
    Most interesting response.
    D.

  5. Gerry Pease says:

    “String Theory” is just a bunch of unobservable fudge factors used to create a “theory of everything.”

  6. oldbrew says:

    Is this a resonance ring? It seems to be stable.

    ‘Orion has a giant dust hula hoop around its waist’

    http://www.newscientist.com/article/dn26977-orion-has-a-giant-dust-hula-hoop-around-its-waist.html#.VOMQTeasWSo

    Quote: “a pattern stood out: a dust ring some 330 light years wide that includes the major star-forming regions in Orion.”

    ‘330 light years wide’ – that’s vast.