A gentle breeze at the speed of light bubbles the ‘Teacup’ galaxy

The IAC detects a jet of energy that changes the temperature of the surrounding gas

A gentle breeze traveling at the speed of light from the center of the Teacup Galaxy is capable of making this suggestive structure bubble. The galaxy, known for its peculiar shape that evokes one of these containers, also behaves, metaphorically, as an infusion would. Their winds heat and reshape the surrounding gas into small or large bubbles with as yet undiscovered consequences for the formation of their stars.

The Teacup Galaxy is so bright, despite its distance -1.3 billion light years. However, what is hidden inside is not as harmless as the lights that illuminate the night sky. At its center is a black hole with an active nucleus. That means matter from the galaxy falls toward the black hole at its center, releasing enormous amounts of energy. This violent interaction is responsible for expelling intense jets of energy or jets out of the galaxy that travel almost at the speed of light.

The result is the creation of winds that interact with the cold gases of the quasar. As the ejecta propagates through the galaxy, it collides with surrounding clouds and gas and, in some cases, pushes this material away as winds. These winds can drastically change the fate of galaxies, as by heating up the gas, they prevent the formation of new stars and halt galactic growth.

But this galaxy also has a peculiarity, and that is that its activity is not seen, as with others, through radio waves. A radio-silent quasar located 1.3 billion light-years away, its nickname comes from the expanding bubbles seen in visible light and radio, one of which forms a bulge resembling the handle of a teacup. In addition, the central region (about 3,300 light-years in size) harbors a young, compact radius jet that is slightly tilted with respect to the galaxy’s disk.

Greater impacts
But even when the energy it gives off is more like a breeze than a wind, its effects are far greater than those of a more powerful jet. ‘It used to be thought that low-powered jets had a negligible impact on the galaxy, but work like ours shows that, even in the case of radio-quiet galaxies, the jet is redistributing and perturbing the gas around it, which will have associated with an impact on the galaxy’s ability to form new stars,” says Cristina Ramos Almeida, a researcher at the IAC and co-author of the study published in the journal Astronomy & Astrophysics Letters.

Specifically, their observations showed that this low-powered, “compact jet” was not only disturbing the distribution and temperature of the surrounding gas, but was also accelerating it in an unusual way.

The team hoped to detect these extreme conditions in the impacted regions along the jet, but when they analyzed the observations, they found that this gas is turbulent and hotter in the direction perpendicular to the jet’s propagation direction.

“This is due to the interaction of the bubble produced by the jet with the surrounding gas, which it heats and disperses as it expands laterally,” explains Anelise Audibert, IAC researcher and lead author of this paper. “Based on comparison with computer simulations, we believe that the orientation between the cold disk and the jet is a crucial factor in effectively driving these crosswinds,” she adds.

Carbon molecules
These scientific results were obtained through observations made in the Chilean desert with the Atacama Large Millimeter/submillimeter Array (ALMA), the team managed to capture the presence of dense and cold gas in the central part of the Teacup galaxy. In particular, they detected the emission of carbon monoxide molecules that can only exist under certain conditions of density and temperature.

The next step for the IAC research group is to observe a larger sample of radio silent quasars with MEGARA, an instrument installed on the Gran Telescopio de Canarias (GTC or Grantecan).

The observations made by these researchers from the Instituto de Astrofísica de Canarias will help to understand the impact of the jets on the thinnest and hottest gas, and to measure the changes in star formation caused by the winds. This is one of the objectives of the QSOFEED project, developed by an international scientific team led by Cristina Ramos Almeida and dedicated to investigating how the winds from supermassive black holes affect the galaxies that host them.