Evidence against baryonic dark matter in elliptical galaxies

1989 ◽  
Vol 346 ◽  
pp. 648 ◽  
Author(s):  
Dennis J. Hegyi ◽  
Keith A. Olive
Keyword(s):  
Dark Matter ◽  
Elliptical Galaxies ◽  
Baryonic Dark Matter

scholarly journals Understanding the internal dynamics of elliptical galaxies without non-baryonic dark matter

2016 ◽  
Vol 463 (2) ◽  
pp. 1865-1880 ◽  
Author(s):  
J. Dabringhausen ◽  
P. Kroupa ◽  
B. Famaey ◽  
M. Fellhauer
Keyword(s):  
Dark Matter ◽  
Elliptical Galaxies ◽  
Internal Dynamics ◽  
Baryonic Dark Matter

scholarly journals MIMAC: aμTPC detector for non-baryonic dark matter search

2009 ◽  
Vol 36 ◽  
pp. 263-268 ◽  
Author(s):  
F. Mayet ◽  
O. Guillaudin ◽  
D. Santos ◽  
A. Trichet
Keyword(s):  
Dark Matter ◽  
Dark Matter Search ◽  
Baryonic Dark Matter

Dark matter in elliptical galaxies

1995 ◽  
Author(s):  
Francesco Bertola ◽  
Alessandro Pizzella
Keyword(s):  
Dark Matter ◽  
Elliptical Galaxies

scholarly journals Thermodynamic Constraints on the Non-Baryonic Dark Matter Gas Composing Galactic Halos

Galaxies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 77
Author(s):  
Anne M. Hofmeister
Keyword(s):  
Dark Matter ◽  
Galactic Halos ◽  
Gas Temperature ◽  
Macroscopic Models ◽  
Available Energy ◽  
Massive Halos ◽  
Classical Thermodynamics ◽  
Halo Gas ◽  
Occupy Central ◽  
Baryonic Dark Matter

To explain rotation curves of spiral galaxies through Newtonian orbital models, massive halos of non-baryonic dark matter (NBDM) are commonly invoked. The postulated properties are that NBDM interacts gravitationally with baryonic matter, yet negligibly interacts with photons. Since halos are large, low-density gaseous bodies, their postulated attributes can be tested against classical thermodynamics and the kinetic theory of gas. Macroscopic models are appropriate because these make few assumptions. NBDM–NBDM collisions must be elastic to avoid the generation of light, but this does not permit halo gas temperature to evolve. If no such collisions exist, then the impossible limit of absolute zero would be attainable since the other available energy source, radiation, does not provide energy to NBDM. The alternative possibility, an undefined temperature, is also inconsistent with basic thermodynamic principles. However, a definable temperature could be attained via collisions with baryons in the intergalactic medium since these deliver kinetic energy to NBDM. In this case, light would be produced since some proportion of baryon collisions are inelastic, thereby rendering the halo detectable. Collisions with baryons are unavoidable, even if NBDM particles are essentially point masses. Note that <0.0001 × the size of a proton is needed to avoid scattering with γ-rays, the shortest wavelength used to study halos. If only elastic collisions exist, NBDM gas would collapse to a tiny, dense volume (zero volume for point masses) during a disturbance—e.g., cosmic rays. NBDM gas should occupy central galactic regions, not halos, since self-gravitating objects are density stratified. In summary, properties of NBDM halos as postulated would result in violations of thermodynamic laws and in a universe unlike that observed.

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