They map the structure of the magnetic field of the Milky Way

The research provides maps of the Milky Way that give a detailed description of the sky in a new frequency range, from 10 to 20 GHz.


The researchers of the Quijote experiment have presented six scientific articles that provide information on the magnetic field of the Milky Way and will help to understand the energy processes that took place at the birth of the Universe.

The Spanish Institute of Astrophysics of the Canary Islands (IAC) is one of those participating, together with the Department of Communications Engineering of Santander and the Institute of Physics of Cantabria (IFCA), both in Spain, as well as the Jodrell Bank Observatory of the University of Manchester, the Cavendish Laboratory (Cambridge) and the IDOM company.

The most accurate map

As explained by the IAC in a statement, in these articles the polarization of the microwave emission of the Milky Way is described more precisely than up to now , something that provides complementary information to that obtained by some space missions (Planck and WMAP). dedicated to the study of the cosmic microwave background (FCM), the fossil radiation from the Big Bang.

The maps provide a detailed description of the sky in a new frequency range, from 10 to 20 GHz, complementary to space missions that have previously observed the sky in microwaves, such as Planck (ESA) and WMAP (NASA), comments José Alberto Rubiño , scientific director of Quijote and principal investigator of the European project Radioforegrounds.

He adds that the polarization of the synchrotron emission from the Milky Way has been characterized with unprecedented precision , and comments that it is the result of the emission of charged particles that move at speeds close to that of light within the magnetic field. galactic.

These maps, the result of almost 9,000 hours of observation, are a unique tool for studying magnetism in the Universe, adds Rubiño.

The cosmic microwave background is a fossil radiation that comes from the first moments of the Universe and that is observed in the domain of radio waves.

Ricardo Génova-Santos, a researcher at the IAC, specifies that this type of radiation is studied by scientists because, by investigating its polarization properties, they intend to find the indirect trace of the existence of gravitational waves generated after the Big Bang.

To access this signal of the origin of the Universe, scientists must remove the emission veil associated with our galaxy and Quixote’s maps provide a tool to carry out this task.

“One of the most interesting results that we have found is that the polarized synchrotron emission from our galaxy is much more spatially variable than previously thought,” comments Elena de la Hoz, a researcher at the Institute of Physics of Cantabria, who adds that the results obtained constitute a reference to help future experiments to detect the cosmological signal.

The detection of said cosmological signal, a very specific pattern in the polarization of the microwave background associated with the presence of gravitational waves generated during the so-called inflationary era, would open a new window to fundamental Physics, Rubiño emphasizes.

He goes on to say that in this way it allows us to explore energy scales billions of times higher than those that can currently be explored from Earth with particle accelerators, and adds: “Their study would allow us to understand the energetic processes that took place at the birth of the Universe “.

a new field

The new Quijote data are also a “unique” tool for studying anomalous microwave emission (EAM), a type of emission first detected about 25 years ago and thought to be produced by rotating particles of very small dust from the interstellar medium that tend to orient themselves due to the presence of the galactic magnetic field.

The polarization properties of these emissions “have to be characterized and understood in detail in order to decontaminate the FCM polarization maps for Cosmology”, comments Frederick Poidevin, a researcher at the IAC.

“With the new Quixote data we have improved our understanding of EAM in multiple regions of our galaxy,” says Denis Tramonte, a researcher at the Purple Mountain Observatory (PMO-CAS, China).

Quixote’s maps have also made it possible to study the microwave emission coming from the galactic center.

The IAC points out that an excess of microwave emission of still unknown origin has recently been detected in this region, but that it could be associated with processes of decay of dark matter particles.

“With Quijote we have confirmed the existence of this excess emission and found evidence that this signal could be polarized. This information is essential to understand the nature of this emission”, comments Federica Guidi, a researcher at the Institut d’Astrophysique de Paris (IAP , France).

In addition, the new Quixote maps have made it possible to carry out a systematic study of more than 700 radio and microwave emission sources, both of galactic and extragalactic origin. EFE