Galaxy Zoo Talk

Green Object near the center

  • metalmania by metalmania

    If you zoom into the SDSS image for this AGZ000ba60, right near the nucleus at 8oclock is a small green object, this doesn't show in DECaLS.
    I don't think it's an asteroid (there's no purple component I can see) plus it looks part of the galaxy.
    Any ideas?

    Posted

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

    Here's a zoomed in SDSS image:

    enter image description here

    It looks real, doesn't it? And it's likely too small to show up in POSS images; has this field been imaged by a CFHT survey perhaps? What does it look like in UKIDSS? If you download SDSS data into DS9, how obvious is the green object in the other four SDSS bands/filters?

    Hope this helps, and happy hunting! 😃

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    The focal point of the spectra is exactly in the middle of the two 'objects', while the photometric object is the galaxy center

    Posted

  • JeanTate by JeanTate in response to Ghost Sheep SWR's comment.

    At first glance, the spectrum seems quite usual:

    enter image description here

    However, if you examine it using the interactive spectrum tool, it turns out to be somewhat unusual! For example, the nebular [NII] 6583 emission line is quite strong, the [OII] 3725/3727 ones rather weak (cf their usual strong appearance), and the H-alpha emission only ~as strong as the [NII] 6583.

    No sign, to my amateur eyes, of anything like a 'green star' in the spectrum. Perhaps it was a transient (the SDSS photometry/images were taken at quite different times from the spectra)?

    Posted