Decades passed AstronomersAstronomers Note that some galaxies are almost empty of them the cloudsthe clouds of nuclear and dusty gases, i.e. where are the reservoirs DownfallDownfall Gravity Star Nurseries. Theorists are trying to understand what could have “killed” these galaxies and some have advanced the idea, supported by calculations and observations, that there must be culprits. A supermassive black holeA supermassive black hole From a million to several billion solar masses are found at the heart of all the large galaxies we know.
When these black holes are fueled by massive streams of matter falling onto them, for whatever reason, cold dark matter filaments or mergers with galaxies after collisions, the matter heats up significantly. growth discgrowth disc Around a giant black hole, which is also rotating. We get plasma and jets of matter, as well as radiation pressurepressure can oppose the downward flow of nuclear matter toward a black hole. The radiation is so intense that we get a cosmic lighthouse clearly visible from billions of miles away.light yearslight years And radiates like all stars in a massive galaxy: quasars.
And here’s the idea: radiation pressureradiation pressure As the flow of, can be so important solar windsolar wind on the tail of a CometComet, that it ejects molecular gas from the interstellar medium into the outer galaxies. They then find themselves bereft of material that can be used to “die” new stars and galaxies, unless they are replenished with gas. This is further proof of the existence of this phenomenon that a team of researchers led by Assistant Professor Dragon Salak (Hokkaido University), Assistant Professor Takuya Hashimoto (University of Tsukuba) and Professor Akio Inoue (Waseda University).
First evidence of quasar-driven suppression of star formation in the early universe
Hokkaido University press release accompanying the publication of the team’s work The Astrophysical Journal (an article on the subject is freely accessible on arXiv) also explains that it ” First evidence of suppression of star formation due to inflows of molecular gas into the host galaxy QuasarQuasar In L’universeuniverse primitive ” was acquired with the famous network of Radio telescopeRadio telescope handsets acting as a large Alma device (Atacama Large Millimeter/Submillimeter Array), in Chile, by precisely studying a quasar-containing galaxy called J2054-0005.
Dragon Salak explains that “ Theoretical work suggests that nuclear gas flows play an important role in the formation and evolution of galaxies from early ages, as they can control star formation. Quasars are particularly energetic sources, so we expect them to be able to produce powerful outflows. “
His colleague Hashimoto explains that “ J2054-0005 is one of the brightest quasars in the distant Universe, so we decided to target this object as an excellent candidate for their study.
” But only Alma had the sensibility and frequency bandfrequency band sufficient to detect the nuclear fluxes that cause observed quasars in the distant early universe.Still in the same press release from Hokkaido University, the method used by Dragon Salak AstrophysicistsAstrophysicists To achieve their goals: The outgoing molecular gas (OH) was discovered by exploitationexploitation. This means that we did not see the microwave radiation coming directly from it nuclearnuclear Oh; Instead, we observed radiation coming from a bright quasar – and absorption means that OH molecules absorb some of the quasar’s radiation. So it was like revealing the presence of gas by seeing a “shadow” projected in front of the light source. “
Did you know ?
In 1963, Martin Schmidt And John Beverley Oak published in the newspaper Nature Especially the results of observations they made using occultation techniques. They tried to determine the optical counterpart of a powerful radio source discovered by another astronomer a few years earlier, Alan Sandage. The source was named 3C 273, which means it was 273E Subject of the Third Cambridge Catalog of Radio Sources.
Schmidt and Oke’s article was a bolt from the blue in the sky of astrophysics and cosmology. Spectral analysis of the star that they identified in the visible Virgo Constellation The hydrogen emission lines are strongly red-shifted. This meant that what appeared to be a star was located outside the Milky Way, but at most a cosmological distance away. To be observable from such a distance, the object must be of incredible luminosity.
This discovery a A quasi-stellar radio sourcea Quasar According to the name proposed in 1964 by an astrophysicist of Chinese origin Hong Yi Chiu, showing that the universe was different in the past, and was therefore evolving. This was not possible within the framework of the standard cosmological model of the time, according to which, although expanding, the universe should appear unchanged to all observers, regardless of their position at the time. On the other hand, the existence of 3C 273 was in complete agreement with the principle of Big Bang, because this predicts that if we observe objects at large enough distances, we will go further and further back into the past and into the history of the evolving universe. It is therefore common to observe a universe billions of light-years away that has a different appearance than the universe it had only millions of years ago, hence the atmosphere close to the Milky Way.
We now know that quasar 3C 273 is located 2.44 billion light-years away within a giant elliptical galaxy.