From IAC-The Institute of Astrophysics of the Canary Islands [Instituto de Astrofísica de Canarias] (ES): “Discovery of relativistic jets blowing bubbles in the central region of the Teacup Galaxy” 

From IAC-The Institute of Astrophysics of the Canary Islands [Instituto de Astrofísica de Canarias] (ES)

Anelise Audibert

Cristina Ramos Almeida

The compact radio jet in the center of the Teacup galaxy blows a lateral turbulent wind in the cold dense gas, as predicted by the simulations. Credit: M. Meenakshi/ D. Mukherjee/ A. Audibert/HST/ ALMA/ VLA.

A study led by Anelise Audibert, a researcher at the Instituto de Astrofísica de Canarias (IAC), reveals a process that explains the peculiar morphology of the central region of the Teacup galaxy, a massive quasar located 1.3 billion light-years away from us. This object is characterized by the presence of expanding gas bubbles produced by winds emanating from its central supermassive black hole. The study confirms that a compact jet, only visible at radio waves, is altering the shape and increasing the temperature of the surrounding gas, blowing bubbles that expand laterally. These findings, based on observations from the ALMA telescope in Chile and hydrodynamical simulations, are published today in the journal Astronomy & Astrophysics Letters [below].

When matter falls into supermassive black holes in the centers of galaxies, it unleashes enormous amounts of energy and is called an active galactic nuclei (or AGN). A fraction of AGN release part of this energy as jets that are detectable in radio wavelengths that travel at velocities close to light speed. While the jet travels across the galaxy, it collides with the clouds and gas around it and in some cases may push this material away in the form of winds. However, which conditions preferentially trigger these winds to blow out the gas from galaxies are still poorly understood.

The effect of jets impacting the content of the galaxies, like the stars, dust, and gas, plays an important role in how galaxies evolve in the Universe. The most powerful radio jets, hosted in ´radio-loud’ galaxies, are responsible for drastically changing the fate of galaxies because they heat the gas, preventing new star formation and galaxy growth. Computer simulations of relativistic jets piercing into disky galaxies predict that jets alter the shape of the surrounding gas by blowing bubbles as they penetrate further into the galaxy. One of the key elements in the simulations that make the jets efficient in driving winds is the angle between the gaseous disk and the jet’s direction of propagation. Surprisingly, less powerful jets, like the ones in ‘radio-quiet’ galaxies, are able to inflict more damage on the surrounding medium than the very powerful ones.

An international scientific team, led by the IAC researcher Anelise Audibert, discovered an ideal case in which to study the interaction of the radio jet with the cold gas around a massive quasar: the Teacup galaxy. The Teacup is a radio-quiet quasar located 1.3 billion light years from us and its nickname comes from the expanding bubbles seen in the optical and radio images, one of which is shaped like the handle of a teacup. In addition, the central region (around 3300 light-years in size) harbors a compact and young radio jet that has a small inclination relative to the galaxy disk.

Effects on star formation

Using observations performed in the Chilean desert with the Atacama Large Millimeter/submillimeter Array (ALMA), the team was able to characterize with an unprecedented level of detail the cold, dense gas in the central part of the Teacup. In particular, they detected the emission of carbon monoxide molecules that can only exist under certain conditions of density and temperature. Based on these observations, the team found that the compact jet, despite its low power, is not only clearly disrupting the distribution of the gas and heating it, but also accelerating it in an unusual way.

The team expected to detect extreme conditions in the impacted regions along the jet, but when they analyzed the observations, they found that the cold gas is more turbulent and warmer in the directions perpendicular to the jet propagation. “This is caused by the shocks induced by the jet-driven bubble, which heats up and blows the gas in its lateral expansion”, explains A. Audibert “Supported by the comparison with computer simulations, we believe that the orientation between the cold gas disk and the jet is a crucial factor in efficiently driving these lateral winds”, she adds.

“It was previously believed that low-power jets had a negligible impact on the galaxy, but works like ours show that, even in the case of radio-quiet galaxies, jets can redistribute and disrupt the surrounding gas, and this will have an impact on the galaxy’s ability to form new stars”, says Cristina Ramos Almeida, an IAC researcher and co-author of the study.

The next step is to observe a larger sample of radio-quiet quasars with MEGARA, an instrument installed on the Gran Telescopio CANARIAS (GTC or Grantecan).

The observations will help us to understand the impact of the jets on the more tenuous and hot gas, and to measure changes in star formation caused by winds. This is one of the goals of the QSOFEED project, developed by an international team led by C. Ramos Almeida at the IAC, whose aim is to discover how winds from supermassive black holes affect the galaxies that host them.

Astronomy & Astrophysics Letters

See the full article here .

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IAC-The Institute of Astrophysics of the Canary Islands [Instituto de Astrofísica de Canarias] (ES) operates two astronomical observatories in the Canary Islands:

Roque de los Muchachos Observatory on La Palma
Teide Observatory on Tenerife.

The Instituto de Astrofísica the headquarters, which is in La Laguna (Tenerife).

Observatorio del Roque de los Muchachos at La Palma (ES) at an altitude of 2400m.

The seeing statistics at ORM make it the second-best location for optical and infrared astronomy in the Northern Hemisphere, after Mauna Kea Observatory Hawai’i.

Mauna Kea Observatories Hawai’i altitude 4,213 m (13,822 ft).

The site also has some of the most extensive astronomical facilities in the Northern Hemisphere; its fleet of telescopes includes the 10.4 m Gran Telescopio Canarias [below], the world’s largest single-aperture optical telescope as of July 2009; the Telescopio Nazionale Galileo (IT) (ES) [below] a 3.58-meter Italian telescope; the William Herschel Telescope (second largest in Europe) [below], and the adaptive optics corrected Swedish 1-m Solar Telescope [below].

Gran Telescopio Canarias [Instituto de Astrofísica de Canarias ](ES) sited on a volcanic peak 2,267 metres (7,438 ft) above sea level.

Isaac Newton Group 4.2 meter William Herschel Telescope at Roque de los Muchachos Observatory on La Palma in the Canary Islands(ES), 2,396 m (7,861 ft).

The Swedish 1m Solar Telescope SST at the Roque de los Muchachos observatory on La Palma Spain, Altitude 2,360 m (7,740 ft).

The observatory was established in 1985, after 15 years of international work and cooperation of several countries with the Spanish island hosting many telescopes from Britain, The Netherlands, Spain, and other countries. The island provided better seeing conditions for the telescopes that had been moved to Herstmonceux by the Royal Greenwich Observatory, including the 98 inch aperture Isaac Newton Telescope (the largest reflector in Europe at that time). When it was moved to the island it was upgraded to a 100-inch (2.54 meter), and many even larger telescopes from various nations would be hosted there.

Tiede Observatory, Tenerife, Canary Islands (ES)

Teide Observatory [Observatorio del Teide], IAU code 954, is an astronomical observatory on Mount Teide at 2,390 metres (7,840 ft), located on Tenerife, Spain. It has been operated by the Instituto de Astrofísica de Canarias since its inauguration in 1964. It became one of the first major international observatories, attracting telescopes from different countries around the world because of the good astronomical seeing conditions. Later the emphasis for optical telescopes shifted more towards Roque de los Muchachos Observatory on La Palma.