Les trous noirs sont plus puissants que prévu – les champs magnétiques pénètrent plus profondément dans les galaxies

Vue d’artiste de Cygnus A, entouré par le tore de poussière et de débris avec des jets partant de son centre. Les champs magnétiques sont illustrés piégeant la poussière près du trou noir supermassif au cœur de la galaxie. Cette étude initiale a motivé la comparaison plus large de l’intensité radio à la polarisation et a été incluse dans l’ensemble de données composites. Crédit : NASA/SOFIA/Lynette Cook

Les champs magnétiques aident les trous noirs à pénétrer plus profondément dans les galaxies

Les trous noirs ont potentiellement une influence encore plus grande sur les galaxies qui les entourent que nous ne le pensions. Et l’Observatoire Stratosphérique d’Astronomie Infrarouge (

SOFIA
SOFIA, l’Observatoire stratosphérique pour l’astronomie infrarouge, est un observatoire d’astronomie infrarouge aéroporté qui est un projet conjoint 80/20 de la NASA et du Centre aérospatial allemand (DLR). Il est basé sur un avion gros porteur Boeing 747SP qui a été modifié pour inclure une grande porte dans le fuselage arrière qui peut être ouverte en vol pour permettre à un télescope réfléchissant de 2,5 m (8,2 pieds) de diamètre d’accéder au ciel.

” data-gt-translate-attributes=”[{” attribute=””>SOFIA) provided a new way to look at their impact.

Active galactic nuclei (AGN) — the central region of a galaxy, which houses its supermassive

“We see that some AGN have very powerful radio jets and some don’t, even though all AGN are intrinsically the same — they all have a supermassive black hole in the center and accrete mass,” said Enrique Lopez-Rodriguez, a research scientist at Stanford University’s Kavli Institute for Particle Astrophysics and Cosmology and lead author on the new SOFIA finding. “We don’t understand why some of them are so powerful, and some of them are not.”

Now, using SOFIA, Lopez-Rodriguez and his team have found that the polarization of infrared light from AGN also increases with their radio loudness, providing a new way to study black hole characteristics.

NASA SOFIA

SOFIA soars over the snow-covered Sierra Nevada mountains with its telescope door open during a test flight. SOFIA is a modified Boeing 747SP aircraft. SOFIA achieved full operational capability in 2014 and concluded its final science flight on September 29, 2022. Credit: NASA/Jim Ross

Motivated by the 2018 SOFIA discovery that the infrared light from the strongest known radio-loud AGN, Cygnus A, was highly polarized, the researchers developed a follow-up observation program with SOFIA to determine whether there’s a relationship between infrared polarization and radio loudness, and if so, why. They looked at the magnetic fields of a total of nine AGN, four of them radio loud and five radio quiet.

From SOFIA observations of light polarization, astronomers can deduce the structure of the magnetic field in the region. In the AGN sample Lopez-Rodriquez and his team studied, these polarizations show that in radio-loud AGN — AGN with strong jets — there’s a donut-shaped magnetic field perpendicular to the jets, along the equator of the AGN. That only radio-loud AGN have such a strong toroidal magnetic field indicates that the field is helping to transfer energy inward, feeding the black hole with matter coming from the host galaxy. The stronger the jets, the stronger the magnetic field, and the more energy there is in the system.

The group was surprised by the strength of the result.

“We were hoping for it, but we weren’t expecting such a nice correlation,” Lopez-Rodriguez said. “There’s so much physics behind it that we don’t understand, and future hydromagnetic models are required.”

Though a lot of science behind these objects remains unexplained, the result implies that black holes are potentially affecting galaxy evolution and jet production quite a bit more than astronomers previously realized. While astronomers typically consider gravity as the only force influencing supermassive black holes, this work shows that magnetic fields can aid in bridging the interface between black holes and matter in their host galaxy. With the help of these magnetic fields, black holes can impact not only the matter immediately around them, but can also work at even larger distances within the galaxy.

SOFIA was a joint project of

Leave a Comment