Radio Galaxy Zoo Talk

ARG0001w1a - extended diffuse emission around spiral galaxy

  • Dolorous_Edd by Dolorous_Edd

    To the S from the ARG field is IC 4234

    A large patch of diffuse emission is visible in NVSS around ( also seems to be visble in GB6 survey )

    SDSS J132259.87+270659.1 - 1237667323799994428 aka IC 4234

    enter image description hereenter image description here

    There is clearly large (and rather complex ) patch of diffuse emission around spiral galaxy, what could it be?

    FIRST (blue) / NVSS (red)

    SE ( from the galaxy ) compact source in FIRST doesn't have optical / IR ID

    enter image description here

    Posted

  • JeanTate by JeanTate

    Cool! 😃 I wonder what the TGSS contour overlay looks like? Will find out ...

    Posted

  • Dolorous_Edd by Dolorous_Edd

    Spoiler

    there is nothing, only triple which is in ARG field is visible

    Posted

  • ivywong by ivywong scientist, admin

    Hi @Dolorous_Edd, how much above the noise is your lowest NVSS contour?

    Posted

  • ChrisMolloy by ChrisMolloy

    Here's a First/NVSS overlay of the above image.

    enter image description here

    The contour overlay image in this post was created from sources, and using methods, described in this RGZ Talk
    thread.     First in red, NVSS cyan.

    NVSS and First parameters are as follows:

    Nnsignoise = 2 (# NVSS noise floor, in sigmas);
    Nsf = np.sqrt(2.0) (# NVSS contour scale factor);
    Nsmooth = 20 (# sigma for gaussian smoothing) (NVSS contours)

    Fnsignoise = 1.5 (# FIRST noise floor, in sigmas);
    Fsf = np.sqrt(3.0) (# FIRST contour scale factor);
    Fsmooth = 4.0 (# sigma for gaussian smoothing) (FIRST contours)

    Posted

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

    That's a really cool image! 😃

    Very unusual morphology for NVSS, wouldn't you say? I wonder how a professional radio astronomer would classify it?

    Posted

  • DocR by DocR scientist

    pretty cool! i'll check it out tomorrow

    Posted

  • DocR by DocR scientist

    This looks real to me. I subtracted out the two compact sources. the extended emission looks to be about 400kpc across. still working...

    Posted

  • DocR by DocR scientist

    The compact source at the bottom has no SDSS or WISE counterpart, so likely an unrelated background source, but curious. The AGN itself, IC4234, is located in a filament outside the Coma cluster, with a differential velocity of about 3000 km/s, so it's not bound to the cluster. I've never seen a source like this before. I'm talking with Tom Jones about how it could be explaned, so the story will continue...

    Posted