Galaxy Zoo Talk

Ionized gas?

  • GoldenRule by GoldenRule

    http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?id=1237648705132625937
    Is this an example of a vorjeworp, ionized gas cloud, or just star formation producing the emission lines? I looked at the chat refrences as well as the ned and the simbad references n I don't understand the difference.

    Posted

  • Budgieye by Budgieye moderator

    white-blue colour - starforming galaxy - spectrum shows blue stars

    bright blue- starburst galaxy with OII areas

    deep blue or bright pink - voorwerpje

    enter image description here

    enter image description here

    http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?id=1237648705132625937

    This colour explanation is good for SDSS images.

    Peas and OIII regions bright blue of one colour has lots of star formation and star explosions, Stars explode and shine UV light on their nebulae, and the oxygen in the nebula re-emits the light. Only one shade of blue is produced , so the colour is pure. So, there are lots of hot supernova nebulae containing hot oxygen producing those OIII emission lines. The temperatures involved is about 50,000 degrees.

    Blue stars white fuzzy blue is a galaxy that has many blue stars. There is a rise in the 4000-5000 angstrom area in the spectrum. Blue is mixed with yellow and orange, so the colour is not pure. So, lots of blue stars shining. The temperature of the stars is between 3,000 and 10,000 degrees.

    So this image has OIII regions in a galaxy of mostly blue stars.

    enter image description here

    enter image description here enter image description here

    AGN-clouds are mostly interstellar hydrogen that is being illuminated by UV light, frin a hot AGN, maybe a million degrees.

    UV light shining on hydrogen, making it hot and emitting deep blue light I think that it is a deep blue colour because the UV light that illuminates the gas cloud is very powerful, and can do more difficult ionizations. The pink

    AGN-clouds, Hanny's Voorwerp and voorwerps are all gas ionized by the nucleus of a galaxy, an AGN

    Info

    Galaxy Redshift Chart https://talk.galaxyzoo.org/#/boards/BGZ0000007/discussions/DGZ0000ulp?page=2

    Spectra guide for SDSS images in Galaxy Zoo Talk https://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=3&comment_id=53fef2ee3d5a77490c0001b6

    AGN clouds, voorwerp, voorwerpje

    Posted

  • GoldenRule by GoldenRule

    In one of the simbads 4 points in the galaxy is labeled SHOC496a HII ionized gas. So does that mean it's just from the star formation?

    Posted

  • Budgieye by Budgieye moderator

    Yes. In astronomy speak, "star formation" often means "lots of Wolf-Rayet stars and supernovae"

    Rapidly formed stars are usually big and blue, and only live for several million years before they explode. That creates lots of UV light that strips electrons from hydrogen, and from the newly created oxygen and nitrogen.

    star formation = supernova

    see

    https://en.wikipedia.org/wiki/H_II_region

    https://en.wikipedia.org/wiki/Wolf–Rayet_star

    Posted