Galaxy rotation curve Definition and 12 Threads

The existence of dark matter was initially proposed to address discrepancies between observed galaxy rotation curves and the expected behavior dictated by our current understanding of gravity. Typically, it's argued that stars at the edges of galaxies rotate faster than expected, leading to...

Hello, What I understood from multiple answers on different threads is that the effect of the time dilation is too small to explain the galaxy rotation curve. I was advised to do some calculations in order to see it myself. And this is what I would like to do but I need some help. - What is...

I apologize for the simple question, but I am trying to understand the Mass Discrepancy-Acceleration Relation and its relationship to ##\mu(x)## (from https://arxiv.org/pdf/astro-ph/0403610.pdf). The mass discrepancy, defined as the ratio of the gradients of the total to baryonic...

I apologize for the simple question, but I have not been able to find the answer. For the inner portion of a galaxy rotation curve (where the outer portion is the part invariant to distance and the inner part is where rotational velocity increases with radius), how much is simply due to...

What is the density of galactic centre? Thus what form of Kepler's law account for the galaxy rotation curve increasing near the galactic centre?

The diagram below is from https://en.wikipedia.org/wiki/Galaxy_rotation_curve . I would much appreciate a derivation explaining the shape of the "Expected from visible disk" curve in the diagram. Naively, based on Newtonian mechanics for the orbital velocity of a circular orbit, V = √GM/R ∝...

How would a galaxy rotation curve look if every matter simply had a 6 times larger mass than the visible? (please neglect how that could be) Wouldn't a same size galaxy then reside in a 6 times larger gravitational well so that the spiral arms would still be in the steep part of the well...

Hi folks, I'm supposed to derive the func. form of the rotation curve for the outer parts of our galaxy, in the absence of dark matter. Im assuming that I treat this as a linear curve, since in reality, dark matter flattens out the curve, when it should continue following the linear(?)...

Do any of you know which article(s) are used to do the "expected" rotation curve for galaxies, that always seem to be used to compare with data for calculating the distribution of dark matter? I'm just trying to find which authors have worked out a published result for the theoretical...

Hi all, this is the problem: Homework Statement A galaxy shows a rotation curve with a given velocity v(r) . r is the distance from the center, c is the speed of light and r_{c} = 1 kpc is constant. I have to find: 1) the mass density profile of the galaxy \rho(r) 2) the total mass M...

Is it possible that the very high concentration of mass at the centers of galaxies is causing a significant enough time dilation to explain a non-negligible part of the rotational curve problem? i.e. time is traveling more slowly in the super-massive, black hole rich cores of galaxies and faster...

Homework Statement Derive and plot the rotation curve of a galaxy with logarithmic potential: \Phi(R, z) = \frac{v_0^2}{2}\ln{(R_c^2 + R^2 + q_{\phi}^{-2} z^2)} where R_c = 2 kpc, q_{\phi} = const. and v_o = 200 kms^{-1}. Note that v_c is defined for z = 0 only. Homework Equations...