Galaxy Zoo Talk

NGC 3081 a barred spiral with resonance ring

  • Budgieye by Budgieye moderator

    The resonance ring is the smaller ring, at to the ends of the bar.

    enter image description here

    http://www.nasa.gov/sites/default/files/styles/full_width_feature/public/hubble_3.jpg?itok=IYvOSGMV

    http://www.nasa.gov/content/goddard/hubble-eyes-golden-rings-of-star-formation

    Taking center stage in this new NASA/ESA Hubble Space Telescope image
    is a galaxy known as NGC 3081, set against an assortment of glittering
    galaxies in the distance. Located in the constellation of Hydra (The
    Sea Serpent), NGC 3081 is located over 86 million light-years from us.
    It is known as a type II Seyfert galaxy, characterized by its dazzling
    nucleus.

    NGC 3081 is seen here nearly face-on. Compared to other spiral
    galaxies, it looks a little different. The galaxy's barred spiral
    center is surrounded by a bright loop known as a resonance ring. This
    ring is full of bright clusters and bursts of new star formation, and
    frames the supermassive black hole thought to be lurking within NGC
    3081 — which glows brightly as it hungrily gobbles up in-falling
    material.

    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-organized star formation.

    Hubble snapped this magnificent face-on image of the galaxy using the
    Wide Field Planetary Camera 2. This image is made up of a combination
    of ultraviolet, optical, and infrared observations, allowing
    distinctive features of the galaxy to be observed across a wide range
    of wavelengths.

    Image credit: ESA/Hubble & NASA; acknowledgement: R. Buta (University
    of Alabama) Text credit: European Space Agency

    Last Updated: May 22, 2015 Editor: Rob Garner

    http://iopscience.iop.org/1538-3881/127/4/1982/fulltext/

    #NGC #NGC3081

    Forum The Kinematics and Dynamics of Galactic Rings The Physics of Resonance http://www.galaxyzooforum.org/index.php?topic=10635.msg125230#msg125230

    Posted

  • Budgieye by Budgieye moderator

    Outside the SDSS footprint ? so we aren't likely to come across it right now.

    FIG. 1 CITED IN TEXT | HIGH-RESOLUTION IMAGE (211 kB) | Next
    Schematic showing the relative shapes, sizes, and major-axis orientations of all of the bar and ring features of NGC 3081, including the "dimples" in the outer R1 ring feature. Here "nr" refers to the nuclear ring, and "nb" to the nuclear (secondary) bar. Axes are labeled in arcsecond offsets relative to the nucleus. North is at the top, and east is to the left.

    enter image description here

    http://iopscience.iop.org/1538-3881/127/4/1982/fulltext/

    Posted