ESO | VLT | MUSE | ALMA (ESO/NRAO/NAOJ) | 2018 Nov 06
Galaxy-Scale Fountain Seen in Full GloryObservations by ALMA and data from the MUSE spectrograph on ESO’s VLT have revealed a colossal fountain of molecular gas powered by a black hole in the brightest galaxy of the Abell 2597 cluster — the full galactic cycle of inflow and outflow powering this vast cosmic fountain has never before been observed in one system.
- Composite image of the Abell 2597 galaxy cluster showing the fountain-like flow of gas powered by the supermassive black hole in the central galaxy. The yellow is ALMA data showing cold gas. The red is data from the MUSE instrument on ESO’s Very Large Telescope showing the hot hydrogen gas in the same region. The blue-purple is the extended hot, ionized gas as imaged by the Chandra X-ray Observatory. Credit: ALMA (ESO/NAOJ/NRAO), Tremblay et al.; NRAO/AUI/NSF, B. Saxton; NASA/Chandra; ESO/VLT/MUSE)
A mere one billion light-years away in the nearby galaxy cluster known as Abell 2597, there lies a gargantuan galactic fountain. A massive black hole at the heart of a distant galaxy has been observed pumping a vast spout of cold molecular gas into space, which then rains back onto the black hole as an intergalactic deluge. The in- and outflow of such a vast cosmic fountain has never before been observed in combination, and has its origin in the innermost 100 000 light-years of the brightest galaxy in the Abell 2597 cluster. ...
Tremblay and his team used ALMA to track the position and motion of molecules of carbon monoxide within the nebula. These cold molecules, with temperatures as low as minus 250–260°C, were found to be falling inwards to the black hole. The team also used data from the MUSE instrument on ESO’s Very Large Telescope to track warmer gas — which is being launched out of the black hole in the form of jets. ...
Together these two sets of data form a complete picture of the process; cold gas falls towards the black hole, igniting the black hole and causing it to launch fast-moving jets of incandescent plasma into the void. These jets then spout from the black hole in a spectacular galactic fountain. With no hope of escaping the galaxy’s gravitational clutches, the plasma cools off, slows down, and eventually rains back down on the black hole, where the cycle begins anew.
This unprecedented observation could shed light on the life cycle of galaxies. The team speculates that this process may be not only common, but also essential to understanding galaxy formation. While the inflow and outflow of cold molecular gas have both previously been detected, this is the first time both have been detected within one system, and hence the first evidence that the two make up part of the same vast process. ...
ALMA | NRAO | ESO | NAOJ | 2018 Nov 06
Infalling and Outflowing Gas Give More Complete Understanding of the Evolution of Galaxies
A Galaxy-Scale Fountain of Cold Molecular Gas Pumped by a Black Hole ~ Grant R. Tremblay et al
- Astrophysical Journal 865(1):13 (20 Sep 2018) DOI: 10.3847/1538-4357/aad6dd
arXiv.org > astro-ph > arXiv:1808.00473 > 01 Aug 2018