Constraints on free-free emission from Anomalous Microwave Emission Sources in the Perseus Molecular Cloud

Abstract

We present observations performed with the Green Bank Telescope at 1.4 and 5 GHz of three strips coincident with the anomalous microwave emission features previously identified in the Perseus molecular cloud at 33 GHz with the Very Small Array. With these observations we determine the level of the low frequency (~1 - 5 GHz) emission. We do not detect any significant extended emission in these regions and we compute conservative 3σupper limits on the fraction of free-free emission at 33 GHz of 27%, 12%, and 18% for the three strips, indicating that the level of the emission at 1.4 and 5 GHz cannot account for the emission observed at 33 GHz. Additionally, we find that the low frequency emission is not spatially correlated with the emission observed at 33 GHz. These results indicate that the emission observed in the Perseus molecular cloud at 33 GHz, is indeed in excess over the low frequency emission, hence confirming its anomalous nature.

Accepted for publication in ApJ

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Cited by in corpus (4)

• The State-of-Play of Anomalous Microwave Emission (AME) Research
• Search for PAHs in the Perseus molecular cloud with the Green Bank Telescope
• Probes of turbulent driving mechanisms in molecular clouds from fluctuations in synchrotron intensity
• Far-infrared to centimeter emission of very nearby galaxies with archival data