Astronomers at the Harvard Center for Astrophysics have mapped the local bubble surrounding our Solar System. A one-of-a-kind map that could help understand the origins of stars and the influences of magnetic fields in the cosmos. The pre-print work is published on the prestigious university’s website (ref.).
The map reveals the probable structure of the magnetic field of the local bubble, a cavity 1,000 light-years wide that surrounds the Sun and the Solar System. But it is not a unique or isolated phenomenon, our galaxy, the Milky Way is full of these so-called superbubbles. The violent explosions of supernovae, disturb these structures. Deflagration, concentrates gas and dust, the fuel to create new stars, on the outer surfaces of the bubbles.
The surfaces of these regions therefore serve as rich sites for the formation of stars and planets. Until now, however, the understanding of the mechanisms that regulate this phenomenon was completely unknown. With the new 3D map of the magnetic field, researchers now have new information. These data could be useful to better explain the evolution of superbubbles and their influence on star formation. “Putting together this 3D map of the local bubble will help us examine superbubbles in new ways” says Theo O’Neill, who led the work of creating the map.
“Space is full of these superbubbles that trigger the formation of new stars and planets and influence the overall shapes of galaxies” added O’Neill. “By learning more about the exact mechanisms that guide the Local Bubble surrounding the Solar System, we can know more about the evolution and dynamics of superbubbles in general”. O’Neill and his colleagues presented the results at the 241st annual meeting of the American Astronomical Society on Wednesday January 11th.
Gaia & Planck
The research was conducted under the guidance of Harvard Professor Alyssa Goodman, in collaboration with Catherine Zucker, Jesse Han and Juan Soler, an expert on magnetic fields in Rome. “From the point of view of basic physics, we have known for some time that magnetic fields must play an important role in many astrophysical phenomena” says Goodman. “But studying these magnetic fields has notoriously been difficult. The difficulty takes us away, but then new observation tools and computational methods give us new impetus. The simulations and investigations of today could finally be good enough to start understanding magnetic fields and how the universe works. From the movements of tiny grains of dust to the dynamics of galaxy clusters.”
The 3D magnetic field map, was based in part on data from Gaia, a space observatory launched by the European Space Agency (ESA). During the measurement of the positions and movements of stars, Gaia was also used to deduce the position of cosmic dust, tracing its local concentrations and showing the approximate boundaries of the Local Bubble. The data was cross-referenced with another space telescope led by ESA, Planck. This latter carried out a sky survey from 2009 to 2013, and was designed to observe the light of the Big Bang.
Specifically, the interesting data from the Planck database is polarized light, light that vibrates in a specific direction. Polarization is produced by dust particles aligned according to the orientation of the magnetic field. From the magnetic field lines, the researchers derived the 3D map of the Local Bubble. “With this map, we can really start probing the influences of magnetic fields on star formation” says Goodman. “And otherwise, you understand better how these fields influence so many other cosmic phenomena.”