scholarly journals Galaxy Rotation Curves Disfavor Traditional and Self-interacting Dark Matter Halos, Preferring a Disk Component or Einasto Function

2021 ◽  
Vol 920 (1) ◽  
pp. L10
Author(s):  
Nicolas Loizeau ◽  
Glennys R. Farrar
2018 ◽  
Vol 27 (02) ◽  
pp. 1850007 ◽  
Author(s):  
Christian G. Böhmer ◽  
Nicola Tamanini ◽  
Matthew Wright

We consider a modification of General Relativity motivated by the treatment of anisotropies in Continuum Mechanics. The Newtonian limit of the theory is formulated and applied to galactic rotation curves. By assuming that the additional structure of spacetime behaves like a Newtonian gravitational potential for small deviations from isotropy, we are able to recover the Navarro–Frenk–White profile of dark matter halos by a suitable identification of constants. We consider the Burkert profile in the context of our model and also discuss rotation curves more generally.


2012 ◽  
Vol 21 (11) ◽  
pp. 1242002 ◽  
Author(s):  
PRITI MISHRA ◽  
TEJINDER P. SINGH

Flat galaxy rotation curves and the accelerating Universe both imply the existence of a critical acceleration, which is of the same order of magnitude in both the cases, in spite of the galactic and cosmic length scales being vastly different. Yet, it is customary to explain galactic acceleration by invoking gravitationally bound dark matter, and cosmic acceleration by invoking a "repulsive" dark energy. Instead, might it not be the case that the flatness of rotation curves and the acceleration of the Universe have a common cause? In this essay we propose a modified theory of gravity. By applying the theory on galactic scales we demonstrate flat rotation curves without dark matter, and by applying it on cosmological scales we demonstrate cosmic acceleration without dark energy.


2004 ◽  
Vol 220 ◽  
pp. 281-286 ◽  
Author(s):  
Roelof S. de Jong ◽  
Susan Kassin ◽  
Eric F. Bell ◽  
Stéphane Courteau

We present a simple technique to estimate mass-to-light (M/L) ratios of stellar populations based on two broadband photometry measurements, i.e. a colour-M/L relation. We apply the colour-M/L relation to galaxy rotation curves, using a large set of galaxies that span a great range in Hubble type, luminosity and scale size and that have accurately measured HI and/or Hα rotation curves. Using the colour-M/L relation, we construct stellar mass models of the galaxies and derive the dark matter contribution to the rotation curves.We compare our dark matter rotation curves with adiabatically contracted Navarro, Frenk, & White (1997, NFW hereafter) dark matter halos. We find that before adiabatic contraction most high surface brightness galaxies and some low surface brightness galaxies are well fit by a NFW dark matter profile. However, after adiabatic contraction, most galaxies are poorly fit in the central few kpc. the observed angular momentum distribution in the baryonic component is poorly matched by ACDM model predictions, indicating that the angular momentum distribution is not conserved during the galaxy assembly process. We find that in most galaxies the dark matter distribution can be derived by scaling up the HI gas contribution. However, we find no consistent value for the scaling factor among all the galaxies.


2016 ◽  
Vol 466 (2) ◽  
pp. 1648-1668 ◽  
Author(s):  
Harley Katz ◽  
Federico Lelli ◽  
Stacy S. McGaugh ◽  
Arianna Di Cintio ◽  
Chris B. Brook ◽  
...  

2019 ◽  
Vol 488 (4) ◽  
pp. 5127-5144 ◽  
Author(s):  
Lizbeth M Fernández-Hernández ◽  
Ariadna Montiel ◽  
Mario A Rodríguez-Meza

ABSTRACT We present a non-parametric reconstruction of the rotation curves (RCs) for 88 spiral galaxies using the LOESS (locally weighted scatterplot smoothing) + SIMEX (simulation and extrapolation) technique. In order to compare methods, we also use a parametric approach, assuming core and cuspy dark matter (DM) profiles: pseudo-isothermal (PISO), Navarro−Frenk–White (NFW), Burkert, Spano, the soliton, and two fuzzy soliton + NFW. As a result of these two approaches, a comparison of the RCs obtained is carried out by computing the distance between the central curves and the distance between the 1σ error bands. Furthermore, we perform a model selection according to two statistical criteria, the Bayesian information criterion and the value of $\chi ^2_{\rm red}$. We work with two groups. The first is a comparison between PISO, NFW, Spano and Burkert, showing that Spano is the most favoured model satisfying our selection criteria. For the second group, we select the soliton, NFW and fuzzy models, resulting in soliton as the best model. Moreover, according to the statistical tools and non-parametric reconstruction, we are able to classify galaxies as core or cuspy. Finally, using a Markov chain Monte Carlo method, for each of the DM models we compute the characteristic surface density, μDM = ρsrs, and the mass within 300 pc. We find that there is a common mass for spiral galaxies of the order of 107 M⊙, which is in agreement with results for dSph Milky Way satellites, independent of the model. This result is also consistent with our finding that there is a constant characteristic volume density of haloes. Finally, we also find that μDM is not constant, which is in tension with the literature.


2019 ◽  
Vol 64 (11) ◽  
pp. 1042 ◽  
Author(s):  
A. M. Gavrilik ◽  
I. I. Kachurik ◽  
M. V. Khelashvili

We elaborate further the м-deformation-based approach to the modeling of dark matter, in addition to the earlier proposed use of м-deformed thermodynamics. Herein, we construct м-deformed analogs of the Lane–Emden equation (for density profiles) and find their solutions. Using these, we plot the rotation curves for a number of galaxies. Different curves describing the chosen galaxies are labeled by respective (different) values of the deformation parameter м. As a result, the use of м-deformation leads to the improved agreement with observational data. For all the considered galaxies, the obtained rotation curves (labeled by м) agree better with data, as compared to the well-known Bose–Einstein condensate model results of T. Harko. Besides, for five of the eight cases of galaxies, we find a better picture for rotation curves, than the corresponding Navarro–Frenk–White (NFW) curves. The possible physical meaning of the parameter м basic for this version of м-deformation is briefly discussed.


1990 ◽  
Vol 124 ◽  
pp. 19-23
Author(s):  
Jane C. Charlton ◽  
Edwin E. Salpeter

AbstractThe distributions of projected separations and radial velocity differences of pairs of galaxies in the CfA and SSRS redshift catalogs are examined. We focus on pairs that fall in low density environments rather than in clusters or large groups. The projected separation distribution is nearly flat, while uncorrelated galaxies would have given one linearly rising with rp. There is no break in this curve even below 50 kpc, the minimum halo size consistent with measured galaxy rotation curves. The significant number of pairs at small separations is inconsistent with the N-body result that galaxies with overlapping halos will rapidly merge, unless there are significant amounts of matter distributed out to a few hundred kpc of the galaxies. This dark matter may either be in distinct halos or more loosely distributed. Large halos would allow pairs at initially large separations to head toward merger, replenishing the distribution at small separations. In the context of this model, we estimate that roughly 10 — 25% of these low density galaxies are the product of a merger, compared with the elliptical / S0 fraction of 18%, observed in low density regions of the sample.


2006 ◽  
Vol 636 (2) ◽  
pp. 721-741 ◽  
Author(s):  
J. R. Brownstein ◽  
J. W. Moffat

2014 ◽  
Vol 89 (6) ◽  
Author(s):  
F. S. Guzmán ◽  
F. D. Lora-Clavijo ◽  
J. J. González-Avilés ◽  
F. J. Rivera-Paleo

2000 ◽  
Vol 119 (4) ◽  
pp. 1579-1591 ◽  
Author(s):  
Frank C. van den Bosch ◽  
Brant E. Robertson ◽  
Julianne J. Dalcanton ◽  
W. J. G. de Blok

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