4 ms·
see https://arxiv.org/abs/astro-ph/0612434 https://arxiv.org/abs/astro-ph/0612434
by FrozenVoid 10y ago
see https://arxiv.org/abs/astro-ph/0612434 https://arxiv.org/abs/astro-ph/0612434
- nonbel 10y ago>"The stars in spiral galaxies are settled thin disks with an exponential surface mass distribution" Can you expand on that post? The paper you linked appears to assume the very thing being questioned here...
- FrozenVoid 10y agoIts explained on the next page(it a simplification) In fact, by relaxing some of the assumptions made above, we have the more general relationship: L ∝ V 2/(+s+q−t) opt (here s, q and t can be band- dependent) that can be even more complex and non-linear when the scaling laws (2), (3), (4) are not just power laws. As a matter of fact, in several different large samples of galaxies it has been found that the TF has different slope and scatter in different bands: a I ≃ 10, s I ∼ 0.4mag, while a B ≃ 7.7, s B ∼ 0.5mag (Pierce & Tully 1992), (Salucci et al. 1993). Moreover, a non linearity in the TF is often found at low rotation velocities (Aaronson et al. 1982).
- nonbel 10y agoThanks, I will take a closer look.