Empirical distributions of galactic $λ$ spin parameters from the SDSS
| dc.creator | Hernandez, X. | |
| dc.creator | Park, Changbom | |
| dc.creator | Cervantes-Sodi, B. | |
| dc.creator | Choi, Yun-Young | |
| dc.date | 2006-07-26 | |
| dc.date | 2006-11-10 | |
| dc.date.accessioned | 2026-07-07T10:23:22Z | |
| dc.date.available | 2026-07-07T10:23:22Z | |
| dc.description | Using simple dimensional arguments for both spiral and elliptical galaxies, we present formulas to derive an estimate of the halo spin parameter $λ$ for any real galaxy, in terms of common observational parameters. This allows a rough estimate of $λ$, which we apply to a large volume limited sample of galaxies taken from the SDSS data base. The large numbers involved (11,597) allow the derivation of reliable $λ$ distributions, as signal adds up significantly in spite of the errors in the inferences for particular galaxies. We find that if the observed distribution of $λ$ is modeled with a log-normal function, as often done for this distribution in dark matter halos that appear in cosmological simulations, we obtain parameters $λ_{0}=0.04 \pm 0.005$ and $σ_λ=0.51 \pm 0.05$, interestingly consistent with values derived from simulations. For spirals, we find a good correlation between empirical values of $λ$ and visually assigned Hubble types, highlighting the potential of this physical parameter as an objective classification tool. | |
| dc.description | 8 pages, 6 figures, expanded final version, MNRAS (in press) | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0607605 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0607605 | |
| dc.identifier | Mon.Not.Roy.Astron.Soc.375:163-170,2007 | |
| dc.identifier | doi:10.1111/j.1365-2966.2006.11274.x | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/175804 | |
| dc.subject | Astrophysics | |
| dc.title | Empirical distributions of galactic $λ$ spin parameters from the SDSS | |
| dc.type | text |