This article presents a conceptual diagram reflecting the current understanding of the distribution of interstellar medium in active galactic nuclei. It shows that dense molecular gas from galaxies is drawn towards black holes, moving along the disk’s surface. Near the black hole, the heat from the accumulated material breaks down this molecular gas, converting it into atoms and plasma. A notable finding is that while a large portion of this mixed interstellar material forms jets ejecting from the galaxy’s center (with plasma jets arising directly above the disk and atomic and molecular jets forming at an angle), a significant amount of these particles return to the disk in a fountain-like manner. This information comes with acknowledgment to ALMA (ESO/NAOJ/NRAO) and the work of T. Izumi and colleagues.
Recent breakthroughs in astrophysics have unveiled new details about gas flows near supermassive black holes, with observations at an impressively detailed light-year scale. These studies have shown that while a considerable volume of gas is attracted towards black holes, only about 3% is consumed. The majority is expelled, then reabsorbed by the host galaxy.
It’s noted that not all matter drawn towards a black hole is ingested; some is ejected as outflows. However, quantifying the ratio of consumed to ejected matter has been challenging.
A global team led by Takuma Izumi, an assistant professor at Japan’s National Astronomical Observatory, utilized the Atacama Large Millimeter/submillimeter Array (ALMA) to study the supermassive black hole in the Circinus Galaxy, situated 14 million light-years away in the Circinus constellation. This black hole is known for its active feeding.
ALMA provided a view of the Circinus Galaxy’s core. The presence of medium-density molecular gas is indicated by carbon monoxide (CO) in red, atomic gas by atomic carbon (C) in blue, high-density molecular gas by hydrogen cyanide (HCN) in green, and ionized gas by the hydrogen recombination line (H36α) in pink. The central dense gas disk, shown in green, spans about 6 light-years. The plasma outflow is almost perpendicular to the disk. This research was supported by ALMA (ESO/NAOJ/NRAO) and T. Izumi’s team.
ALMA’s Contribution to Deciphering Black Hole Enigmas
ALMA’s exceptional resolution enabled the team to be the first globally to accurately measure both inflow and outflow around the black hole at a scale of just a few light-years. By analyzing the movement of gases in various states (molecular, atomic, and plasma), they determined the black hole’s feeding efficiency to be roughly 3%. They also verified that gravitational instability prompts the inflow.
The study further revealed that most of the expelled outflows lack the velocity to leave the galaxy entirely. Instead, they are reintegrated into the areas surrounding the black hole, gradually gravitating back towards it.
This research, titled “Supermassive black hole feeding and feedback observed on subparsec scales” by Takuma Izumi and his team, was published on 2 November 2023 in Science (DOI: 10.1126/science.adf0569). The study received funding from the National Astronomical Observatory of Japan and the Japan Society for the Promotion of Science.
Frequently Asked Questions (FAQs) about Black Hole Astrophysics
What are the primary findings about black holes from recent astrophysical studies?
Recent studies have revealed that supermassive black holes attract a considerable amount of gas, but only about 3% of this gas is consumed. The rest is expelled and recycled back into the galaxy.
How did ALMA contribute to understanding black holes?
ALMA’s high-resolution capabilities allowed researchers to measure gas inflows and outflows around black holes to a few light-years scale, determining a black hole’s feeding efficiency and the recycling process of expelled gases.
What was unique about the supermassive black hole in the Circinus Galaxy observed by ALMA?
The supermassive black hole in the Circinus Galaxy, 14 million light-years away, was actively feeding. ALMA’s observations provided detailed insights into the gas dynamics around this black hole.
What did the observations reveal about the gas around black holes?
The observations showed that while most of the gas is ejected from black holes, it doesn’t escape the galaxy but is instead recycled back, gradually moving towards the black hole again.
Who led the international research team in these groundbreaking observations?
The research team was led by Takuma Izumi, an assistant professor at the National Astronomical Observatory of Japan.
More about Black Hole Astrophysics
- Science Journal Article on Black Hole Observations
- National Astronomical Observatory of Japan
- ALMA Telescope and Black Hole Research
- Circinus Galaxy Black Hole Study
- Takuma Izumi’s Astrophysical Research
- Supermassive Black Holes and Galactic Gas Dynamics
- Advances in Astrophysics
- Gravitational Instability and Black Hole Feeding
- Gas Recycling in Galaxies
- The Atacama Large Millimeter/submillimeter Array (ALMA)