Magnetic Fields in the Formation of Massive Stars
Josep M. Girart,1,*
Maria T. Beltrán,2,
Qizhou Zhang,3
Ramprasad Rao,4
Robert Estalella2
Massive stars play a crucial role in the production of heavy
elements and in the evolution of the interstellar medium, yet
how they form is still a matter of debate. We report high-angular-resolution
submillimeter observations toward the massive hot molecular
core (HMC) in the high-mass star-forming region G31.41+0.31.
We find that the evolution of the gravitational collapse of
the HMC is controlled by the magnetic field. The HMC is simultaneously
contracting and rotating, and the magnetic field lines threading
the HMC are deformed along its major axis, acquiring an hourglass
shape. The magnetic energy dominates over the centrifugal and
turbulence energies, and there is evidence of magnetic braking
in the contracting core.
2 Departament d'Astronomia i Meteorologia (IEEC-UB). Institut de Ciencies del Cosmos y Unitat Associada a CSIC, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalunya, Spain.
3 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA.
4 Academia Sinica, Institute of Astronomy and Astrophysics, 645 North Aohoku Place, Hilo, HI 96720, USA.
Present address: Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy.
* To whom correspondence should be addressed. E-mail: girart@ieec.cat
