From Instituto de Astrofísica de Canarias – IAC: “A faint galaxy that outshines the others”


From Instituto de Astrofísica de Canarias – IAC

Manu Astrónomus

Almudena Prieto:
Alberto Ardila Rodríguez:

Image of the active galaxy ESO little light LLAGN 428-G14.

According to an international investigation which involved scientists from the Institute of Astrophysics of the Canary Islands (IAC) , luminous galaxies with active nuclei have little enough to expel gas quantities similar to those removed galaxies with bright nuclei much energy.

The gas is essential in the process of formation of a galaxy. During the early stages, the amount of gas present determines the number of stars that will be in it. Active galaxies nucleus (AGN, for its acronym in English) they are those that have a higher brightness region in its center. This bright area is caused by the presence of a massive black hole, the effect of its gravity, accumulated material around a process known as accretion.

Supermassive black holes heat the surrounding gas and pushing part of it to the outside Galaxy (feedback effect). It was thought that AGN lower luminosity did not have enough to expel large amounts of gas energy. But an international study, in which two researchers from the Institute of Astrophysics of the Canary Islands (IAC) involved, proves otherwise.

The red dots represent the spatial distribution and morphology due to high
ionization of the gas cloud, due to the strong emission of the jets hole
black of this active galaxy. Credit: D.May et al.

In the article, recently published in the journal Monthly Notices of the Royal Astronomical Society, they analyzed the galaxy ESO 428-G14, which has a slightly luminous AGN. Thanks to the data obtained with integral field spectrograph SINFONI the Very Large Telescope (VLT) , the European Southern Observatory (ESO) detected that this galaxy has the strongest feedback effect seen in one of its class.


ESO VLT at Cerro Paranal in the Atacama Desert, •ANTU (UT1; The Sun ),
•KUEYEN (UT2; The Moon ),
•MELIPAL (UT3; The Southern Cross ), and
•YEPUN (UT4; Venus – as evening star).
elevation 2,635 m (8,645 ft) from above Credit J.L. Dauvergne & G. Hüdepohl atacama photo,

“In this galaxy dim glow explains Daniel May, researcher at the Institute of Astronomy, Geophysics and Atmospheric Sciences at the University of Sao Paulo and first author of the publication-, the jet is responsible for carrying out the work of expulsion gas. However, in the most luminous active nuclei, this task is performed by the radiation emitted by the nucleus itself.”

a): Image HI Brγ λ21661 Å emission (total flow 24 ± 1 × 10-15 erg s-1 cm-2)
the dashed ellipses highlight the ‘helix’ into two substructures, b1 and b2. (B): The line
of [Si VI] of all cubes combined data (DS2), with a smaller FOV and
greater signal / noise ratio. The contrast shows the fainter structures and b4 b3.
The cross marks the position of the AGN. The flow bar is in units of
10 -19 erg s-1 cm-2 A-1. Credit: D.May et al.

Radio galaxies, which are AGN with powerful jets, expels the material at rates between 1 and 50 solar masses per year. ESO 428-G14, which has a modest jet, it is in the range of 3 to 8 solar masses per year. “With these data -comenta Almudena Prieto, IAC researcher and co-author of the study, is the least luminous galaxy with the strongest feedback observed to date.”

“Our findings open a debate on the role of supermassive black holes as efficient in the heart of galaxies, regardless of its brightness engines,” says Alberto Ardila Rodríguez, a visiting researcher and co-author IAC.

Through further studies, the team of scientists attempt to discover the nature of the process makes it possible as little light as ESO 428-G14, core so efficiently removing gaseous matter. “He’s probably related to own source of gas in the galaxy,” said May.

See the full article here.

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The Instituto de Astrofísica de Canarias(IAC) is an international research centre in Spain which comprises:

The Instituto de Astrofísica, the headquarters, which is in La Laguna (Tenerife).
The Centro de Astrofísica en La Palma (CALP)
The Observatorio del Teide (OT), in Izaña (Tenerife).

These centres, with all the facilities they bring together, make up the European Northern Observatory(ENO).

The IAC is constituted administratively as a Public Consortium, created by statute in 1982, with involvement from the Spanish Government, the Government of the Canary Islands, the University of La Laguna and Spain’s Science Research Council (CSIC).

The International Scientific Committee (CCI) manages participation in the observatories by institutions from other countries. A Time Allocation Committee (CAT) allocates the observing time reserved for Spain at the telescopes in the IAC’s observatories.

The exceptional quality of the sky over the Canaries for astronomical observations is protected by law. The IAC’s Sky Quality Protection Office (OTPC) regulates the application of the law and its Sky Quality Group continuously monitors the parameters that define observing quality at the IAC Observatories.

The IAC’s research programme includes astrophysical research and technological development projects.

The IAC is also involved in researcher training, university teaching and outreachactivities.

The IAC has devoted much energy to developing technology for the design and construction of a large 10.4 metre diameter telescope, the ( Gran Telescopio CANARIAS, GTC), which is sited at the Observatorio del Roque de los Muchachos.

Gran Telescopio Canarias at the Roque de los Muchachos Observatory on the island of La Palma, in the Canaries, SpainGran Telescopio CANARIAS, GTC