Jeans mass
E59371
The Jeans mass is the critical mass above which a cloud of gas becomes gravitationally unstable and begins to collapse, playing a key role in the formation of stars and galaxies.
Aliases (1)
- Jeans length ×1
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
astrophysical concept
→
gravitational instability criterion → physical quantity → |
| appliesTo |
interstellar molecular clouds
→
primordial gas in the early universe → protogalactic gas clouds → |
| approximateFormula |
M_J ∝ T^{3/2} ρ^{-1/2}
→
M_J ≈ (5 k_B T / G μ m_H)^{3/2} (3 / 4πρ)^{1/2} → |
| assumes |
Newtonian gravity
→
isothermal gas → small perturbations in an infinite medium → uniform density → |
| balances |
thermal pressure against gravitational attraction at the stability threshold
→
|
| characterizes |
onset of gravitational instability in a self-gravitating gas
→
|
| condition |
cloud remains stable when mass is below Jeans mass
→
collapse occurs when cloud mass exceeds Jeans mass → |
| contrastedWith |
Bonnor–Ebert mass
→
|
| dependsOn |
gas density
→
gas temperature → mean molecular weight of the gas → sound speed in the gas → |
| describes |
critical mass for gravitational collapse of a gas cloud
→
|
| dimension |
mass
→
|
| directlyProportionalTo |
3/2 power of gas temperature
→
|
| field |
astrophysics
→
cosmology → star formation theory → |
| historicalContext |
introduced in early 20th century gravitational instability analyses
→
|
| influences |
fragmentation scale of collapsing clouds
→
typical mass scale of forming stars → |
| inverselyProportionalTo |
square root of gas density
→
|
| namedAfter |
James Jeans
→
|
| relatedTo |
Jeans instability
→
Jeans length → free-fall time → self-gravity of gas clouds → thermal pressure support → virial theorem → |
| roleIn |
formation of galaxies
→
formation of stars → formation of stellar clusters → |
| symbol |
M_J
→
|
| usedIn |
initial mass function studies
→
models of molecular cloud fragmentation → numerical simulations of star formation → structure formation in the early universe → |
Referenced by (2)
| Subject (surface form when different) | Predicate |
|---|---|
|
Chandrasekhar limit
→
|
relatedConcept |
|
Jeans mass
("Jeans length")
→
|
relatedTo |