Astronomers first saw the flicker of a quasar - ForumDaily
The article has been automatically translated into English by Google Translate from Russian and has not been edited.
Переклад цього матеріалу українською мовою з російської було автоматично здійснено сервісом Google Translate, без подальшого редагування тексту.
Bu məqalə Google Translate servisi vasitəsi ilə avtomatik olaraq rus dilindən azərbaycan dilinə tərcümə olunmuşdur. Bundan sonra mətn redaktə edilməmişdir.

Astronomers first saw the flicker of a quasar

Quasars are one of the brightest objects in the Universe and in fact are active galactic nuclei. Observing these space objects is extremely important for basic science. It is known that quasars draw energy from black holes located in their very heart. But this energy is not always stable, so the quasar glows, rather, not like a lantern, but like a beacon, now fading, then rising again.

Before scientists could not see directly both phases of a luminescence at the same object. For the first time, this was done by a team from Yale University in the USA, which registered a coefficient of brightness on one of the quasars on 6-7 points less than was registered several years before.

“We studied hundreds of thousands of quasars in this zone of the starry sky. And finally, we found one object in the “off” phase,” says astrophysicist Megan Urry from Yale University, lead author of the study.

Along with her colleague Stephanie LaMassa and other members of the astrophysics department, Urry observed quasars located in the so-called Stripe 82 zone, which stretches along the celestial equator. This region is one of the most studied in the observable universe, as it has been scanned by several devices, including the 2,5-meter telescope of the Sloan Digital Sky Survey program.

“The observed effect is a bit like turning a light on with a switch. In this case, we witnessed how the source of the quasar's power - the black hole - was depleted and stopped feeding the galactic core as actively as before. The lifespan of a quasar is incredibly long, so we are simply happy that in one human lifetime we were able to see two phases of the glow of this grandiose beacon of the Universe at once,” says LaMassa.

For astronomers, it was also important not only to register a drop in the brightness of a quasar, but also to see the weakening of its broad emission lines. Visible in the optical spectrum, these lines are in fact the signatures of a gas that is still too far from the horizon of a black hole event to be absorbed by it, but already close enough to it to acquire titanic energy, which the black hole accretion disk tells it.

As described in a Yale press release, the change in emission lines suggests that the black hole literally “went on a diet” and, as a result, began to release less energy. That is why the quasar entered the darkening phase.

Urry and her colleagues ruled out the possibility of a background phenomenon in which the dimming of the quasar could be caused simply by the passage of a cloud of dust and gas across the disk of the brightest object. Scientists did this by analyzing data from various observations, as well as comparing optical and x-ray observations, Vesti.ru writes.

“This discovery is, first of all, of great importance for astrophysicists studying black holes. The fact that we directly saw the energy decay of this enormous object changes scientific understanding of how black holes grow,” explains LaMassa.

In the U.S. USA Science space
Subscribe to ForumDaily on Google News


 
1072 requests in 1,067 seconds.