This is the oldest observed example of such a wind to date and, according to its discoverers, is a tell-tale sign that huge black holes have a profound effect on the growth of galaxies since the earliest history of the Universe.
At the center of many large galaxies lurks a supermassive black hole that is millions to billions of times more massive than the Sun. Interestingly, the mass of the black hole is roughly proportional to the mass of the central region (bulge) of the galaxy in the nearby Universe. At first glance this may seem obvious, but it is actually very strange. The reason is that the sizes of galaxies and black holes differ by about 10 orders of magnitude. Based on this proportional relationship between the masses of two objects that are so different in size, astronomers believe that galaxies and black holes grew and evolved together (coevolution) through some kind of physical interaction.
“The question is when did the galactic winds arise in the Universe?”
A galactic wind can provide this kind of physical interaction between black holes and galaxies. A supermassive black hole swallows a large amount of matter. As that matter begins to move at high speed due to the black hole’s gravity, it emits intense energy, which can push the surrounding matter outward. This is how the galactic wind is created. “The question is when did the galactic winds arise in the Universe?” He says it’s a statement Takuma Izumi, lead author of the research paper and researcher at the National Astronomical Observatory of Japan (NAOJ). “This is an important question because it is related to an important problem in astronomy: how did galaxies and supermassive black holes coevolve?”
The research team first used NAOJ’s Subaru telescope to search for supermassive black holes. Thanks to their wide-field observation capabilities, they found more than 100 galaxies with supermassive black holes in the Universe more than 13 billion years ago.
The research team then used the high sensitivity of the ALMA (Atacama Large Millimeter / submillimeter Array) to investigate the motion of gas in the host galaxies of black holes. ALMA observed the HSC galaxy J124353.93 + 010038.5 (hereinafter J1243 + 0100), discovered by the Subaru Telescope, and captured radio waves emitted by dust and carbon ions in the galaxy.
The oldest observed galactic wind
Detailed analysis of the ALMA data revealed that there is a high-speed gas flow moving at 500 km per second at J1243 + 0100. This gas flow has enough energy to push stellar material away from the galaxy and stop activity. star formation. The gas flow found in this study is truly a galactic wind, and it is the oldest observed example of a galaxy with a large galactic-size wind. The previous record holder was a galaxy some 13 billion light years away; so this observation sets the beginning back another 100 million light years.
The team also measured the motion of the silent gas in J1243 + 0100 and estimated that the mass of the galaxy’s bulge, based on its gravitational balance, was approximately 30 billion times that of the Sun. The mass of the supermassive black hole in the galaxy, estimated by another method, was about 1% of that. The mass ratio of the bulge to the supermassive black hole in this galaxy is almost identical to the mass ratio of black holes to galaxies in the modern Universe. This implies that the coevolution of supermassive black holes and galaxies has been occurring since less than a billion years after the birth of the Universe.
“Our observations support recent high-precision computer simulations that have predicted that coevolutionary relationships existed as early as 13 billion years ago,” says Izumi. “We are planning to observe a large number of such objects in the future, and we hope to clarify whether the primordial coevolution seen on this object is an accurate picture of the general Universe at that time.”