Radio Galaxy Zoo Talk

Spiral Galaxy

  • Tobend by Tobend

    Found this very clear source in the centre of a spiral galaxy in SDSS. One might imagine the radio shows a jet viewed not quite end on. I'd appreciate some expert comments. How commonly are these seen etc. if there's a link to a discussion thread that'd be great. Is there a tag for tees? Thanks

    Posted

  • JeanTate by JeanTate in response to Tobend's comment.

    CAUTION: I am not an expert.

    However, I'll offer some comments! 😛

    The radio source is compact, and - as far as I can tell - is at the same position as the nucleus of the spiral galaxy. This is quite common, if the supermassive black hole at the center of the nucleus is surrounded by an 'active' accretion disk, making it an AGN (active galactic nucleus). And the spectrum of the region around the nucleus - as shown in this SDSS page - has a feature which is often seen in AGNs (strong emission lines). However, strong emission lines are also found in star-forming regions, and many spiral galaxies have active star-forming regions in the nuclei (our own galaxy, the Milky Way, included). Further, star-forming regions are the home of many supernovae, and supernova remnants are radio sources.

    In short, I think you need more data than I looked at to tell if the radio source here is associated with an AGN or a nuclear star-forming region (or both). However, there's no sign of any jet (as far as I can see).

    The jets (and lobes) we so often see in RGZ are rarely associated with spiral galaxies. In fact, raynorris (SCIENTIST) says only two or three are known (see this thread)! 😮 Why is that? I don't know (and he didn't answer my question 😦)

    Posted

  • Tobend by Tobend

    Thanks for the helpful response Jean.

    Posted