baryonic Tully–Fisher relation (in MOND context)
E808787
The baryonic Tully–Fisher relation in the MOND context is an empirical law, central to Milgrom’s modified gravity framework, linking a galaxy’s total baryonic mass to the fourth power of its asymptotic rotation velocity without invoking dark matter.
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
astrophysical relation
ⓘ
empirical law ⓘ galactic scaling relation ⓘ |
| abbreviation | BTFR ⓘ |
| appliesTo |
gas-rich dwarf galaxies
ⓘ
late-type spiral galaxies ⓘ low surface brightness galaxies ⓘ |
| assumes |
asymptotically flat rotation curve
ⓘ
galaxy is rotationally supported ⓘ |
| baryonicMassIncludes |
cold gas mass
ⓘ
other detectable baryonic components ⓘ stellar mass ⓘ |
| category | relation between mass and kinematics in galaxies ⓘ |
| constantInvolved |
MOND acceleration constant a_0
ⓘ
Newtonian gravitational constant G ⓘ |
| contrastWith |
classical Tully–Fisher relation based only on luminosity
ⓘ
dark-matter-based explanations of galaxy rotation curves ⓘ |
| coreStatement | the total baryonic mass of a rotationally supported galaxy scales as the fourth power of its asymptotic circular velocity ⓘ |
| dependsOn | deep-MOND regime where accelerations are much smaller than a_0 ⓘ |
| empiricalFeature |
slope close to 4 in log–log space
ⓘ
zero-point consistent with a_0 inferred from other MOND phenomenology ⓘ |
| excludes | non-baryonic dark matter ⓘ |
| field |
galaxy dynamics
ⓘ
modified gravity ⓘ observational cosmology ⓘ |
| historicalContext | developed in the 1980s as part of Milgrom’s original MOND proposal ⓘ |
| implies | outer rotation velocity is determined by baryonic mass distribution alone in MOND ⓘ |
| mathematicalForm |
M_b = (V_f^4) / (G a_0) in the deep-MOND limit
ⓘ
M_b ∝ V_f^4 ⓘ |
| observationalStatus | well supported by data for many disk galaxies ⓘ |
| origin | MOND modification of the relation between acceleration and Newtonian gravity ⓘ |
| predicts |
small intrinsic scatter in the mass–velocity relation
ⓘ
tight correlation between baryonic mass and outer rotation velocity ⓘ |
| proposedBy | Mordehai Milgrom NERFINISHED ⓘ |
| relatedConcept |
mass discrepancy–acceleration relation
ⓘ
radial acceleration relation ⓘ |
| relatesQuantity |
asymptotic rotation velocity of a galaxy
ⓘ
total baryonic mass of a galaxy ⓘ |
| roleInMOND |
key phenomenological success of MOND
ⓘ
used to fix the numerical value of the MOND acceleration scale a_0 ⓘ |
| scaleInvarianceProperty | in deep-MOND limit the dynamics become scale invariant leading to M_b ∝ V^4 ⓘ |
| testedBy |
HI rotation curve surveys
ⓘ
near-infrared photometry of stellar disks ⓘ |
| theoreticalFramework | Modified Newtonian Dynamics NERFINISHED ⓘ |
| usedFor |
constraining galaxy formation models
ⓘ
estimating baryonic masses from rotation curves ⓘ testing modified gravity theories ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.