Saturday, June 22, 2024

NFW And Einasto DM Halos Don't Work

Neither of the leading models for dark matter particle distributions in dark matter halos can accommodate the observed reality that galaxies have an inner core, rather than an inner cusp. 

[A]n ideal spherically symmetric stellar system with isotropic velocities and an inner core cannot reside in a Navarro, Frenk, and White (NFW) gravitational potential. . . . stellar cores are also inconsistent with Einasto potentials. This result may have implications to constrain the nature of DM through interpreting the stellar cores often observed in dwarf galaxies.
From  Jorge Sanchez Almeida, "Einasto gravitational potentials have difficulty to hold spherically symmetric stellar systems with cores" arXiv:2406.13613 (June 19, 2024) (RNAAS complementing our previous paper Sanchez Almeida et al. (2023, ApJ, 954, 153; doi: https://doi.org/10.3847/1538-4357/ace534)).

9 comments:

neo said...

arXiv:2406.01705 (hep-ph)
[Submitted on 3 Jun 2024]
Dark Matter
Marco Cirelli, Alessandro Strumia, Jure Zupan

We review observational, experimental and theoretical results related to Dark Matter.

Comments: 510 pages
Subjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)
Cite as: arXiv:2406.01705 [hep-ph]

x17 mentioned

andrew said...

510 pages!

Maybe not at the top of my reading list.

neo said...

I ask Stacy McGaugh if he's going to read it and he said yes

it's an updated latest review

almost like a free textbook on Dark Matter

andrew said...

@neo

Textbook length review articles certainly have their place. I'm not really knocking it. But, not being a professional astrophysicist I just don't have time to read it.

neo said...

there is a section for MOND

neo said...

Bad news for dark matter: This data doesn't fit at all


One of the biggest ongoing dramas in science is whether or not dark matter is real. A new update speaks strongly against dark matter and gives a boost to its alternative: Modified Newtonian Dynamics. Let’s have a look.

Paper: https://arxiv.org/abs/2406.09685

https://www.youtube.com/watch?v=n33aurhg788

andrew said...

I have, of course, already blogged that paper at https://dispatchesfromturtleisland.blogspot.com/2024/06/flat-rotation-curves-extend-long-way.html

neo said...

MOND has problems in both larger scales than galaxies like galaxies clusters and large scale structures and possibly smaller larger scales like wide binaries and CMB

andrew said...

CMB is very large scale and MOND has managed it. MOND also predicted early galaxy formation.

The jury is out on wide binaries. Some researchers say it strongly supports MOND others disagree, when both are drawing on basically the same data.

MOND underestimates galaxy cluster effects, although there is a similar scaling law seen there with a different slope.