Dice Question Streamline Icon: https://streamlinehq.com

Origin of the spectral-type dependence in YSO radio luminosities

Determine which physical processes produce the 3 GHz radio emission underlying the observed dependence of radio luminosity density and detection fraction on stellar spectral type among Taurus–Auriga young stellar objects in the Karl G. Jansky Very Large Array Sky Survey Quick Look images.

Information Square Streamline Icon: https://streamlinehq.com

Background

The paper reports a monotonic increase in radio detection fractions from late to early spectral types in Taurus–Auriga young stellar objects (YSOs), with cumulative distributions showing a significant luminosity enhancement for earlier-type stars. This pattern indicates a strong spectral-type dependence in 3 GHz radio luminosity densities.

However, the data are limited to a single frequency band and Stokes I (total intensity), preventing measurement of radio spectral indices or polarization and, therefore, hindering identification of the underlying emission mechanisms. The authors note that the origin of the dependence is unclear and suggest that magnetic activity or binary interactions could be responsible, but cannot determine the dominant process with the current data.

References

The origin of the observed dependence for YSOs nevertheless remains unclear. Two limitations of this study are that VLASS Quick Look images provide data at i) a single frequency band, and ii) with Stokes I (total intensity), and thus cannot robustly measure radio spectral index nor polarization that can be used to infer underlying radio emission mechanisms. Thus, we cannot yet determine which physical processes are responsible for the observed emission.

— The Radiowave Hunt for Young Stellar Object Emission and Demographics (RADIOHEAD): A Radio Luminosity${-}$Spectral Type Dependence in Taurus${-}$Auriga YSOs (2501.06188 - Rahman et al., 10 Jan 2025) in Subsubsection 'Interpreting the spectral type dependence' (Section 3.3.2)