Radio Galaxy Zoo Talk

ARG00037b7 Is it a Star forming cloud or a GALAXY Radio Source?

  • 1001G by 1001G

    enter image description here

    SDSS J144601.71+082945.8 Radio Source Galaxy.

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  • 42jkb by 42jkb scientist, admin

    This looks to be a galaxy that has gone through an interaction with another galaxy. The radio emission looks to be coming from the "centre" of the galaxy and could be the start of an AGN which usually occurs during during an interaction or merger. The star is in the foreground.

    Posted

  • JeanTate by JeanTate in response to 1001G's comment.

    Host is z_sp 0.035 SDSS J144601.95+082946.5, whose nucleus - where the FIRST radio emission originates - may be hidden by dust:

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    The spectrum being of a star-burst region (red square), and not the nucleus (cyan circle to its right), may explain why the strong emission lines are more characteristic of a starburst than an AGN:

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    Later I will do a WISE overlay, or perhaps a FIRST overlay on a Luptonized WISE image, to see how strongly the nucleus shines through in longer wavelengths.

    Boilerplate: SDSS image per http://skyservice.pha.jhu.edu/DR10/ImgCutout/getjpeg.aspx, FIRST (red) contours derived from the FITS file produced using SkyView with Python code described in this RGZ Talk thread. Image center (J2000.0) is the galactic object SDSS J144601.95+082946.5; "z_sp" its SDSS spectroscopic redshift.

    Posted

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

    Later I will do a WISE overlay, or perhaps a FIRST overlay on a Luptonized WISE image, to see how strongly the nucleus shines through in longer wavelengths.

    I quite like this one; it's a Luptonized WISE composite, with band 1 (3.4μ) as blue, 3 (12μ) as green, and 4 (22μ) as red, and linear scaling:

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    The blue blob is the bright foreground star; the red 'halo' reflects the fact that band 4 resolution is lower than that of band 3; and the yellow color the fact that the band 3 and 4 emission is ~comparable.

    But is the WISE IR peak ~the same as the FIRST one? Or is it closer to where the SDSS spectroscopic fiber was positioned? Let's see ...

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    WISE band 4 (22μ) contours in lime. Within the rather poor resolution limits of band 4, it seems pretty clear that the IR and radio peaks are the same. So, this is very likely a 'hidden' AGN, with intense starformation taking place elsewhere (that's what the SDSS spectrum picked up).

    But is there more?

    The FIRST contours are not quite circular, and there are two 'bumps'. Yes, this is a very 'local' galaxy, so the radio luminosity is pretty low; nevertheless, can we perhaps see the beginnings of a jet? One that extends beyond the optical galaxy?

    What do you think?

    The images in this post were created from sources, and using methods, described in this RGZ Talk post. The object at the center of the images is SDSS J144601.95+082946.5.

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