Direct evidence for magnetohydrodynamic disk winds driving rotating outflows in protostar HOPS 358

arXiv (Cornell University)

Abstract

Angular momentum removal is a fundamental requirement for star and planet formation, yet the mechanisms driving this process remain debated. Magnetohydrodynamic disk winds, launched along magnetic field lines from extended disk regions, offer a promising solution, particularly in regions where magnetorotational turbulence is weak. Here we present high-resolution Atacama Large Millimeter/submillimeter Array observations of the Class 0 protostar HOPS 358, revealing a rotating, nested outflow structure traced by H2CO, SO, and CH3OH emission. The outflow preserves the disk's rotational sense and is aligned with the disk axis, providing direct observational evidence for a magnetically launched disk wind. From the measured kinematics, we derive a dimensionless magnetic lever arm of approximately 2.3 and constrain the wind-launching region to radii of 10-18 astronomical units within the planet-forming zone. These results demonstrate that magnetohydrodynamic disk winds operate during the deeply embedded phase, efficiently extracting angular momentum while shaping disk evolution and establishing initial conditions for planet formation.

Authors 7

1. Chul-Hwan Kim
2. Jeong-Eun Lee

   Seoul National University

   Affiliation as printed

   Department of Physics and Astronomy , Seoul National University , 1 Gwanak-ro , Gwanak-gu , 08826 , Seoul , Republic of Korea

   SNU Astronomy Research Center , Seoul National University , 1 Gwanak-ro , Gwanak-gu , 08826 , Seoul , Republic of Korea

3. Doug Johnstone

   Herzberg Institute of Astrophysics · University of Victoria

   Affiliation as printed

   Department of Physics and Astronomy , University of Victoria , 3800 Finnerty Rd , Elliot Building , Victoria , V8P 5C2 , British Columbia , Canada

   NRC Herzberg Astronomy and Astrophysics , 5071 West Saanich Rd , Victoria , V9E 2E7 , British Columbia , Canada

4. Gregory J. Herczeg

   Peking University

   Affiliation as printed

   Department of Astronomy , Peking University , Yiheyuan 5 , Haidian Qu , 100871 , Beijing , China

   Kavli Institute for Astronomy and Astrophysics , Peking University , Yiheyuan 5 , Haidian Qu , 100871 , Beijing , China

5. Chin‐Fei Lee

   Institute of Astronomy and Astrophysics, Academia Sinica · Academia Sinica

   Affiliation as printed

   Institute of Astronomy and Astrophysics , Academia Sinica , No. 1 , Sec. 4 , Roosevelt Rd , Taipei , 106216 , Taiwan

6. Logan Francis Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory , Leiden University , Gorlaeus Building , Einsteinweg 55 , Leiden , 2300 RA , South Holland , The Netherlands

7. Patrick Sheehan

   National Radio Astronomy Observatory

   Affiliation as printed

   National Radio Astronomy Observatory , 520 Edgemont Rd , Charlottesville , 22903 , Virginia , USA