Speaker
Description
The observed correlation between the far-infrared and radio luminosities of galaxies illustrates the close connection between star formation and cosmic-ray production. Intriguingly, recent LOFAR observations find a peculiar radio excess in galaxies with low star-formation rates and high stellar masses. We show that recycled/millisecond pulsars (MSPs) can dominate the nonthermal emission in these massive quiescent galaxies and explain the excess. This is in line with recent gamma-ray observation suggesting that MSPs may also efficiently accelerate cosmic-ray electrons. We find that MSP-based models provide a significantly improved fit to the LOFAR data. We discuss the implications for the radio and gamma-ray excesses in M31 and local electron and positron observations.
Keywords
"Pulsars; cosmic-ray electrons; radio emission; galaxies"
| Subcategory | Theoretical Results |
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