Radio Galaxy Zoo Talk

Classification?

  • BoazWildcat by BoazWildcat

    Would greatly appreciate an explanation of the radio pattern here. Checked out the WISE and FIRST data but still can't figure it out. I would've guessed they were jets, but the radio waves seem to be originating from the "orbs" on the top, center and bottom.

    Posted

  • ivywong by ivywong scientist, admin

    In this subject, our line-of-sight is roughly perpendicular to the jet axis. Some jets are also "blobbier" than others. Check out the examples shown in the Spotter's Guide (located to the left on the "Classify" pages) for a taste of how different each jet can be.

    Posted

  • Dolorous_Edd by Dolorous_Edd

    Hmm the host is a bit unusual

    What is going on here? Few galaxies close to each other?

    enter image description here

    Posted

  • akapinska by akapinska scientist

    Note, that they have various redshifts estimated (well, as much as z_ph is reliable) - not really similar ones, so close to each other on the image plane, but not physically.

    Posted

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

    SDSS J120452.77+293004.2, at z_ph 0.655 ± 0.1648/0.570 ± 0.2250, would seem to be a long way away. And it's certainly the host!

    enter image description here

    The strange colors - red on one side, green the other - may be telling us something (if they're not artifacts); perhaps they're EELRs (extended emission line regions, a.k.a. voorwerpjes, AGN clouds), with one reddened by dust? Perhaps the host is a lot closer than z ~0.61? Without at least a spectrum we can only speculate ... 😦

    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 galaxy SDSS J120452.77+293004.2; "z_ph" its SDSS photometric redshift.

    Posted

  • 42jkb by 42jkb scientist, admin in response to JeanTate's comment.

    z = 0.61 is indeed far away and the majority of bright FRII radio galaxies live at z > 1. To me radio galaxies are the sign posts of the early Universe. SDSS redshifts are detected for galaxies living a z < 1 ( well depending on what type of redshift was used).

    Not too sure what is going on here with the red wispy signature around the host - could turn out to be something very interesting.

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  • Dolorous_Edd by Dolorous_Edd

    DSS 2 Red

    Lets try to rule out artifact hypotesis? IMO object is clearly extended in SW and NE direction which is consistent with SDSS

    enter image description here

    WISE magnitudes

    w1mag = 12.289

    w2mag = 11.096

    w3mag = 8.304

    w4mag = 5.716

    Color - color

    W1 - W2 = 1.193

    W2 - W3 = 2,792

    Posted

  • ivywong by ivywong scientist, admin

    Thanks @DolorousEdd for checking. I think that you're right that it's not an artefact. However, it's more difficult at this point to figure out if it's confusion between multiple galaxies seen in projection or if it is indeed an EELR (as suggested by @JeanTate)

    Posted