Related Experiment Video
Updated: Apr 21, 2026
07:17
Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry
Published on: August 1, 2017
14.8K
Turbulent heating in galaxy clusters brightest in X-rays.
I Zhuravleva1, E Churazov2, A A Schekochihin3
11] Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, California 94305-4085, USA [2] Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305-4060, USA.
Nature
|November 4, 2014
Summary
Turbulent heating in galaxy clusters balances energy losses in the hot intracluster medium (ICM). This process resolves the gas cooling problem, explaining observations of X-ray-emitting systems.
Area of Science:
- Astrophysics
- Cosmology
- Plasma Physics
Background:
- The intracluster medium (ICM) in galaxy clusters is a hot, X-ray-emitting plasma, constituting the majority of baryonic matter.
- Radiative energy losses in the ICM cores are significant, leading to gas cooling on timescales shorter than the system's age.
- Unchecked cooling contradicts observations, suggesting a heating mechanism is required to maintain the ICM's hot state.
Purpose of the Study:
- To investigate the mechanism responsible for heating the intracluster medium (ICM) and counteracting radiative cooling.
- To determine if turbulent heating can adequately compensate for energy losses in galaxy cluster cores.
- To explore the universal applicability of this heating mechanism in various X-ray-emitting gas-rich systems.
Main Methods:
- Utilized deep X-ray data from galaxy clusters.
- Developed and applied a novel data analysis method to directly quantify the ICM heating rate.
- Evaluated heating specifically from the dissipation of turbulence within the ICM.
Main Results:
- Turbulent heating was found to be sufficient to offset radiative cooling in the ICM.
- The heating rate from turbulence appears to balance radiative cooling locally at each radius.
- This suggests turbulence plays a crucial role in regulating ICM temperature and preventing excessive cooling.
Conclusions:
- Turbulent heating is identified as a plausible and effective solution to the gas cooling problem in galaxy cluster cores.
- This mechanism likely resolves the discrepancy between theoretical cooling and observed ICM properties.
- The findings have broader implications for understanding gas-rich systems, including galaxy groups and elliptical galaxies.
Related Concept Videos
01:24Turbulent Flow
895
Turbulent flow is characterized by unpredictable fluctuations in velocity and pressure, which result in a chaotic fluid movement distinct from the orderly patterns of laminar flow. While laminar flow is governed by smooth, parallel layers with minimal mixing, turbulent flow exhibits highly irregular, three-dimensional patterns. This behavior arises due to instabilities in the fluid's velocity profile, and amplifies as the flow velocity increases. Minor disturbances, known as turbulent...
895
01:20Mechanisms of Heat Transfer II
4.3K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
4.3K
01:20Maxwell-Boltzmann Distribution: Problem Solving
2.3K
Individual molecules in a gas move in random directions, but a gas containing numerous molecules has a predictable distribution of molecular speeds, which is known as the Maxwell-Boltzmann distribution, f(v).
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
2.3K
02:44Heating and Cooling Curves
23.0K
When a substance—isolated from its environment—is subjected to heat changes, corresponding changes in temperature and phase of the substance is observed; this is graphically represented by heating and cooling curves.
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance,...
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance,...
23.0K
01:10Detection of Black Holes
1.7K
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
1.7K
01:25Heat Capacities of an Ideal Gas III
2.1K
The number of independent ways a gas molecule can move along straight line, rotate, and vibrate is called its degrees of freedom. Supposing d represents the number of degrees of freedom of an ideal gas, the molar heat capacity at constant volume of an ideal gas in terms of d is
2.1K