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Measuring the ionisation fraction in a jet from a massive protostar
R Fedriani1,2, A Caratti O Garatti3,4, S J D Purser3
1Dublin Institute for Advanced Studies, School of Cosmic Physics, Astronomy & Astrophysics Section, 31 Fitzwilliam Place, Dublin, D02 XF86, Ireland. fedriani@cp.dias.ie.
Nature Communications
|August 11, 2019
Summary
Massive star formation may involve disc accretion, similar to low-mass stars. This study found similar ionization fractions in massive protostellar jets, suggesting a unified shock ionization mechanism across the stellar mass spectrum.
Area of Science:
- Astrophysics
- Star Formation
- Protostellar Jets
Background:
- Massive star formation mechanisms are not fully understood.
- Protostellar jets are crucial for angular momentum removal during stellar collapse.
- Observing jets from massive stars is challenging due to distance and dust.
Purpose of the Study:
- To investigate if massive stars form via disc accretion like low-mass stars.
- To determine the ionization fraction in jets from massive protostars.
- To compare ionization fractions across the protostellar mass spectrum.
Main Methods:
- Analyzed spatially coincident infrared and radio emission from the massive protostar G35.20-0.74N.
- Determined the ionization fraction within the protostellar jet.
Main Results:
- The ionization fraction in the jet of G35.20-0.74N was found to be approximately 5-12%.
- This ionization fraction is comparable to values observed in jets from low-mass young stars.
Conclusions:
- The findings imply a unified shock ionization mechanism in protostellar jets across a wide range of stellar masses, up to at least 10 solar masses.
- This supports the hypothesis that massive stars may form through disc accretion, similar to their low-mass counterparts.
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