Radio Galaxy Zoo Talk

Sources restarting in different directions

  • WizardHowl by WizardHowl

    This source looks like it has restarted at least once in a different direction. FIRST shows two pairs of lobes at a slight angle to each other and perhaps also a fainter/more diffuse third pair at a much larger angle . The host is SDSS J094034.35+113139.8 Z_sp=0.075 and appears to be, optically, a normal elliptical galaxy. There is strong emission in the spectrum which is classed as AGN but the shape is typical of a red+dead type and there are also the expected absorption features.

    It is my understanding that restarted sources are moderately rare but I don't know how rare or what percentage of sources come into this category. Sources restarting in different directions are rarer, as are those restarting more than once (I think only a handful of these are known?) so if this has restarted twice and in a different direction each time, it would be highly unusual. This makes me look for alternative interpretations but the fact all three pairs of lobes share the same origin despite their differing orientation makes me inclined to rule out interference from any nearby sources - not that there appear to be any bright sources in either FIRST or NVSS for some distance. What do others think?

    Posted