A new study has begun this analysis process and has monitored an area that covers the equivalent of 15 times the full moon.
Many people will remember the experiments in school with iron filings and magnetic bars to reveal your magnetic field. However, it is not so easy to capture the magnetic field of the Milky Way. The new method of measuring the field relies on the tiny grains of dust that permeate the space between stars.
Gaia’s Milky Way in motion (3D)
The difficulty of measuring the magnetic field of the Milky Way
The grains of dust They are similar in size to smoke particles, but are not spherical. Like a ship that drifts with the current, the longitudinal axis of the dust particles tends to align with the local magnetic field. As they do so, they emit a glow at the same frequency as the cosmic background radiation and this is what astronomers have been tuning into.
The particles not only They shine but also absorb starlight that passes through them as if they were polarizing filters. The polarization of light is familiar to photographers who might use polarizing filters to darken skies and manage reflections. The phenomenon of polarization refers to the propagation of light. As it moves through a medium, it transports energy from one place to another, but along the way it shows wave characteristics.
The wave nature is composed of alternating displacements of the medium through which they move (imagine a wave in water). The displacement is not always the same as the direction of travel; Sometimes it is parallel and other times it is perpendicular. In polarization, the displacement is limited to a single direction.
In the particles of interstellar space, Polarizing properties capture the magnetic field and polarize the light traveling through them revealing the details of the magnetic field. As on Earth, magnetic field lines are of crucial importance for galactic evolution. They regulate the formation of starsshape the structure of a galaxy and, like giant galactic rivers, shape and direct the flow of gas around the galaxy.
Researchers from the Interuniversity Institute of High Energy in Belgium used the study PASIPHAE, an international collaboration to explore magnetic field polarization in interstellar dust, to start the process. They measured the polarization of more than 1,500 stars covering an area of sky no more than 15 times the size of the full moon.
The team then used Gai astrometry satellite dataThere is a new algorithm to map the galaxy’s magnetic fields in that part of the sky. The study is published in the journal Astronomy & Astrophysics.
This is the first time a large-scale project has attempted to map the Milky Way’s gravitational field.. The full mapping will take some time to complete, but when it is complete it will provide a great view not only of the magnetic field of galaxies but of the evolution of galaxies throughout the universe.
Reference
V. Pelgrims et al, The first degree-scale starlight-polarization-based tomography map of the magnetized interstellar medium, Astronomy & Astrophysics (2024). DOI: 10.1051/0004-6361/202349015
This entry was published in News on Apr 29, 2024 by Francisco Martín León
