An article published in “The Astrophysical Journal” reports the discovery of high-speed gas flows pushed by the supermassive black hole at the center of a galaxy over 13 billion light-years from Earth. A team of researchers led by Takuma Izumi of the National Astronomical Observatory of Japan (NAOJ) used the ALMA radio telescope to observe the galaxy HSC J124353.93+010038.5, or simply J1243+0100. It’s the oldest known galaxy so far with a wind of that size. This shows how supermassive black holes can heavily influence the galaxies that host them and that this has been happening since the universe was very young.
The birth and evolution of galaxies and supermassive black holes that typically are at their center are an important subject of study in the field of astronomy. According to current models, there’s a coevolution between galaxies and supermassive black holes, which means that they evolve together, a process that occurs through interactions such as a galactic wind. This type of event can be generated when a supermassive black hole swallows large amounts of materials that move around it at high speeds emitting energy that pushes the outermost materials away.
In quasars’ case, the energy emitted is so high as to generate electromagnetic emissions so strong as to make them the brightest objects in the universe. That’s very useful for detecting very distant galaxies that we see as they were when the universe was very young. Discovered thanks to the Subaru telescope, J1243+0100 is an example of a primordial quasar, as we see it as it was about 13.1 billion years ago, one of more than 100 primordial quasars discovered in a specific research.
The ALMA (Atacama Large Millimeter/submillimeter Array) radio telescope, inaugurated in March 2013, was used for follow-up observations of the quasar J1243+0100. Taking advantage of this instrument’s extraordinary sensitivity, it was possible to detect the moving gas in that galaxy thanks to radio emissions from the dust and carbon ions pushed by the supermassive black hole at speeds reaching 500 kilometers per second.
The quasar’s activity has a significant influence on the galaxy because the galactic wind pushes away other materials, including the hydrogen needed to form new stars. Basically, the quasar is inhibiting star formation. That’s an important conclusion to understand under what conditions a supermassive black hole can have such an effect and under which conditions it can favor star formation instead.
An important result confirming the theory of the coevolution of galaxies and their supermassive black holes comes from the estimates of their masses in the galaxy J1243+0100. Observations of galaxies in the modern universe, and therefore at relatively short distances, showed a proportionality between those values with a difference of ten orders of magnitude. That proportionality was also found in J1243+0100, showing that there was the same type of coevolution in the early universe.
To understand the mechanisms of coevolution between galaxies and their supermassive black holes, the researchers intend to study many other primordial quasars. This will allow first of all to verify the theory of coevolution and to search for objects in different phases of growth, hoping to be able to observe the beginning of a galactic wind, a crucial moment in that coevolution.
