Black hole growth,

Question 1

what is black hole feedback?

Answer 1

Black hole feedback refers to the process by which energy released from the accretion of matter onto a supermassive black hole influences the surrounding environment, such as the galaxy in which the black hole resides. This feedback mechanism can take different forms, including thermal feedback associated with higher accretion rates and kinetic feedback associated with lower accretion rates. The energy injected by black holes can impact the galactic atmosphere, regulate star formation, and influence the overall evolution of galaxies.

Question 2

What is Baryon lifting?

Answer 2

Baryon lifting refers to the process by which energy injected by a central black hole into the circumgalactic medium (CGM) of a galaxy increases the entropy and cooling time of the gas, effectively lifting the entire atmosphere of the galaxy

Question 3

What is circum Galactic Medium and what is its significance?

Answer 3

The gas surrounding galaxies outside their disks or interstellar medium and inside their virial radii is known as the circumgalactic medium (CGM).
The CGM is a source of a galaxy’s star-forming fuel, the venue for galactic feedback and recycling, and perhaps the key regulator of the galactic gas supply.

Question 4

What is the importance of Baryon lifting?

Answer 4

This process is believed to be necessary for the long-term quenching of star formation in galaxies, as it limits the supply of cold gas needed for star formation

Question 5

What is quenching? What are the factors affecting it?

Answer 5

Star formation quenching refers to the process by which the formation of new stars in a galaxy is suppressed or halted.
This can occur due to various factors such as feedback from supermassive black holes, depletion of gas reservoirs, or environmental influences

Question 6

Why is quenching essential to understand?

Answer 6

Quenching is essential for understanding the evolution of galaxies, as it plays a crucial role in regulating the growth and properties of galaxies over cosmic time.

Question 7

What is Cosmological Halos?

Answer 7

Spherical regions of matter that surround galaxies and contain dark matter, gas, and stars

Question 8

What is Kinetic Energy Input?

Answer 8

The amount of energy injected by a central black hole into the circumgalactic gas, which is necessary for long-term quenching of star formation

Question 9

What is Thermal-Mode Feedback:?

Answer 9

A mode of feedback in which energy is released in pulses to limit radiative losses of the injected feedback energy, coupling more efficiently with the circumgalactic medium

Question 10

What is Eddington Luminosity:?

Answer 10

The maximum luminosity that a source of radiation can achieve when the outward force due to radiation pressure is balanced by the inward gravitational force.

Question 11

What is the Binding Energy of Baryons:?

Answer 11

The energy required to disperse the baryons in a galaxy’s halo, is crucial for understanding the quenching of star formation.

Question 12

What is a Halo Gas Fraction?

Answer 12

The fraction of gas present in a galaxy’s halo, which can be influenced by feedback processes

Question 13

What is Thermal Feedback?

Answer 13

A mode of feedback in which energy is released thermally to regulate the properties of the surrounding gas and influence star formation.

Question 14

What is Kinetic Feedback?

Answer 14

A mode of feedback in which energy is released in the form of kinetic energy to influence the surrounding gas and regulate star formation.

Question 15

What is Central Entropy?

Answer 15

The measure of disorder or randomness in the central region of a galaxy which can be influenced by feedback processes.

Question 16

What is Cooling Time?

Answer 16

The time it takes for a gas cloud to cool down and form new stars, which can be affected by feedback mechanisms

Question 17

What is Starburst Galaxies?

Answer 17

Galaxies that undergo a rapid burst of star formation, often triggered by external factors such as galaxy interactions or mergers

Question 18

What is Feedback Efficiency?

Answer 18

The effectiveness with which energy released by black holes or other sources influences the surrounding environment and regulates star formation.

Question 19

Here is the story of the paper. Revise once and read for the refresher.

Answer 19

Once upon a time, in the vast expanse of the universe, there existed galaxies with supermassive black holes at their centers. These black holes were not mere cosmic entities but powerful sources of energy that influenced the very fabric of their galactic homes. As matter spiraled into these black holes, a process known as accretion, immense amounts of energy were released in the form of radiation and jets, a phenomenon known as black hole feedback. This feedback had a profound impact on the surrounding environment, including the galaxy itself.

One crucial consequence of this black hole feedback was baryon lifting, where the injected energy lifted the gas in the galaxy’s circumgalactic medium, increasing its entropy and cooling time. This process effectively lifted the entire atmosphere of the galaxy, influencing the formation of new stars within it. The energy injected by the central black hole played a key role in regulating star formation, as it limited the supply of cold gas needed for the birth of new stars.

As star formation was quenched in these galaxies, the connection between black hole growth, baryon lifting, and the suppression of star formation became apparent. The binding energy of the halo’s baryons was closely linked to the growth of the central black hole, suggesting that quenching resulted from the lifting of the baryons in the halo. This intricate dance between black hole feedback, baryon lifting, and star formation quiescence highlighted the interconnected nature of galaxy evolution.

Observations revealed that the mass of a galaxy’s central black hole correlated closely with its velocity dispersion, indicating a causal link between galaxy evolution and black hole growth. The shutdown of star formation, known as quenching, was found to be influenced by both galactic structure and black hole growth, with feedback energy eruptions playing a crucial role in limiting black hole growth.

In the cosmic symphony of black holes, halos, and star formation, the story of baryon lifting and quenching unfolded. The energy released by black holes lifted the baryons in the galaxy’s halo, influencing the formation of stars and shaping the evolution of galaxies. This intricate web of connections between black hole feedback, baryon lifting, and star formation quiescence painted a vivid picture of the cosmic ballet that governed the destiny of galaxies in the universe.

Question 20

What are the unique findings of this paper?

Answer 20

The unique finding of the paper is that despite the anomalous relation between black hole growth and halo mass in the IllustrisTNG simulations, both black hole growth and the quenching of star formation are indeed linked to baryon lifting.

Question 21

What does the State Of The Art idiom mean?

Answer 21

the highest point of technological achievement at a particular time

Question 22

What is TNG simulation?

Answer 22

The TNG (IllustrisTNG) simulation is a state-of-the-art cosmological hydrodynamical simulation that aims to model the formation and evolution of galaxies in the universe. It is an extension of the original Illustris simulation and stands for “The Next Generation” simulation.

Question 23

Against which constraints, were the computational results from TNG simulation compared?

Answer 23

Observational constraints and theoretical models

Question 24

Which simulations were compared in the study to find discrepancies in black hole masses at different halo masses?

Answer 24

The study compared simulations from IllustrisTNG and EAGLE to find discrepancies in black hole masses at different halo masses.

Question 25

What adjustments to simulation parameters are suggested in the paper to better align with observations and theoretical predictions?

Answer 25

The paper suggests adjustments to simulation parameters to better align with observations and theoretical predictions, particularly in the context of black hole masses at different halo masses.

Question 26

What drives the transition to quiescence in galaxies according to the study?

Answer 26

The transition to quiescence in galaxies is driven by kinetic feedback, with energy injection lifting baryons in the halo, decreasing gas pressure, and increasing cooling time.

Question 27

Which feedback mode is highlighted as being less effective in the study?

Answer 27

The study highlights that thermal feedback is less effective compared to kinetic feedback in driving the transition to quiescence in galaxies.

Question 28

What determines the feedback mode and star formation behavior in galaxies according to the research?

Answer 28

The black hole mass and cumulative kinetic energy input are key factors that determine the feedback mode and star formation behavior in galaxies.

Question 29

How does the study suggest that the efficiency of feedback in lifting baryons and quenching star formation depends on?

Answer 29

The study suggests that the efficiency of feedback in lifting baryons and quenching star formation depends on the balance between kinetic and thermal modes of feedback.

Question 30

What is the influence of the black hole mass and energy injected into the circumgalactic medium on the price of feedback for quenching star formation?

Answer 30

The simulations show that the price of feedback for quenching star formation is influenced by the black hole mass and the energy injected into the circumgalactic medium.

Question 31

How does the transition to a quiescent state in galaxies generally occur according to the research?

Answer 31

The transition to a quiescent state in galaxies generally occurs near a halo mass of around 10^12 solar masses, where the cumulative kinetic energy input exceeds the halo’s baryonic binding energy scale.

Question 32

What is the role of black hole growth in the suppression of star formation in galaxies as discussed in the paper?

Answer 32

Black hole growth plays a crucial role in the suppression of star formation in galaxies, with the transition to a quiescent state coinciding with the cumulative kinetic energy input exceeding the halo’s baryonic binding energy scale

Question 33

How do the EAGLE and TNG100 simulations compare with observational points in terms of predicting black hole masses in more massive halos?

Answer 33

The EAGLE and TNG100 simulations overlap with observational points up to a halo mass of around 10^13.5 solar masses but predict smaller black hole masses in more massive halos, indicating discrepancies in predicting black hole masses at different halo masses.

Question 34

What is the significance of the specific star formation rate (sSFR) in relation to the black hole-circumgalactic medium (CGM) relation?

Answer 34

The specific star formation rate (sSFR) aligns with the black hole-circumgalactic medium (CGM) relation, indicating a connection between star formation quenching and black hole feedback