Super Bubbles of Gas Detected Around Massive Black Holes
In a study[1] led by Sandy Morais, a PhD student at Instituto de Astrofísica e Ciências do Espaço (IA[2]) and Faculty of Sciences of the University of Porto (FCUP), researchers found massive super bubbles of gas and dust around two distant radio galaxies[3], about 11.5 billion light-years away.
Andrew Humphrey (IA & University of Porto), the leader of the project commented: “By studying violent galaxies like these, we have gained a new insight into the way supermassive black holes affect the evolution of the galaxies in which they reside.”
The researchers used two of the largest observatories available today, the Keck II (Hawaii) and the Gran Telescópio de Canárias (GTC), to observe TXS0211-122 and TXS 0828+193, two powerful radio galaxies, harboring the most energetic type of active galactic nuclei (AGN) known. This type of galaxy houses the most massive black holes and have the most powerful continuous energy ejections known.
The team discovered expanding super bubbles of gas around each of TXS 0211-122 and TXS 0828+193, most likely caused by “feedback” activity whereby the AGN injects vast quantities of energy into its host galaxy, creating a powerful wind that sweeps up gas and dust into an expanding super bubble.
Study of the symbiosis between the supermassive black hole and the galaxy is a key to understanding the evolution of the most massive galaxies. Ultraviolet emission from the black hole’s accretion disk can inhibit star formation temporarily, by ionizing the Interstellar medium, and the great outflows of gas towards the black hole can lead to permanent inhibition of star formation.
Notes:
1. The article “Ionization and feedback in Lyman alpha haloes around two radio galaxies at z ~ 2.5” was published in the journal Monthly Notices of the Royal Astronomical Society Vol. 465, issue 3, March 2017 (http://dx.doi.org/10.1093/mnras/stw2926).
2. The Instituto de Astrofísica e Ciências do Espaço (Institute of Astrophysics and Space Sciences — IA) is the largest Portuguese research unit of space sciences, which integrates researchers from University of Porto and University of Lisbon, and encompasses most of the field’s national scientific output. It was evaluated as Excellent in the last evaluation from the European Science Foundation (ESF). IA’s activity is funded by national and international funds, including Fundação para a Ciência e a Tecnologia (UID/FIS/04434/2013), POPH/FSE and FEDER through COMPETE 2020.
3. Radio galaxies are a type of galaxy with an ‘active galactic nucleus’ (AGN) at their centre. This AGN consumes material like gas at such a high rate that it emits powerful radiation across the entire electromagnetic spectrum. The AGN also launches powerful jets of material that glow brightly at radio frequencies.
