Radio Galaxy Zoo Talk

completely isolated radio source

  • WizardHowl by WizardHowl

    the radio signal here is completely #isolated and has no IR emission anywhere near it. Does this mean it is not an extragalactic source or that the host galaxy has no IR emission at this wavelength? What types of galaxies might have no emission in this part of the IR and are there examples for the Spotters' Guide? Have not been doing this long but have seen several already where there is no IR match or only a very weak signal. Note that this radio signal is a singular compact source. Are there any known AGB stars with radio emission in the dataset for reference?

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  • KWillett by KWillett scientist, admin, translator

    Radio sources with no IR counterpart at all are rare, although they do certainly exist. In the initial ATLAS-SWIRE paper, astronomers found 31/1276 sources had no IR counterparts - only 2.5%. The information we have on these is limited, given only a radio detection.

    Results so far indicate that they're usually compact in the radio (so you won't see extended structure in RGZ). They are likely smaller than the typical galaxy, and a leading theory is that they are very high-redshift galaxies for which the radio emission is driven by an AGN. We don't see the galaxy because it's too obscured by dust and/or it's too faint because it's far away.

    Other theories, such as the conjecture that some of these objects might be pulsars (spinning neutron stars in our own galaxy), are also a possibility.

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