REVIEW 6 cited by
A universal angular momentum profile for galactic halos
Not yet reviewed by Pith; the record is open.
This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.
SPECIMEN: schema-true, not a live event
T0 review · schema-true
One-sentence machine reading of the paper's core claim.
pith:XXXXXXXX · record.json · timestamp
read the original abstract
[Abridged] We study the angular-momentum profiles of a statistical sample of halos drawn from a high-resolution N-body simulation of the LCDM cosmology. We find that the cumulative mass distribution of specific angular momentum, j, in a halo of mass Mv is well fit by a universal function, M(<j) = Mv \mu j/(j_0+j). This profile is defined by one shape parameter (\mu or j_0) in addition to the global spin parameter \lambda. It follows a power-law over most of the mass, and flattens at large j, with the flattening more pronounced for small values of \mu. Compared to a uniform sphere in solid-body rotation, most halos have a higher fraction of their mass in the low- and high-j tails of the distribution. The spatial distribution of angular momentum in halos tends to be cylindrical and is well-aligned within each halo for ~80% of the halos. We investigate two ideas for the origin of this profile. The first is based on a revised version of linear tidal-torque theory combined with extended Press-Schechter mass accretion, and the second focuses on j transport in minor mergers. Finally, we briefly explore implications of the M(<j) profile on the formation of galactic disks assuming that j is conserved during an adiabatic baryonic infall. The implied gas density profile deviates from an exponential disk, with a higher density at small radii and a tail extending to large radii. The steep central density profiles may imply disk scale lengths that are smaller than observed. This is reminiscent of the "angular-momentum problem" seen in hydrodynamic simulations, even though we have assumed perfect j conservation. A possible solution is to associate the central excesses with bulge components and the outer regions with extended gaseous disks.
Forward citations
Cited by 6 Pith papers
-
Learning the Universe with cosmological rescaling of merger trees and semi-analytic galaxy formation models
Rescaling merger trees with a one-parameter halo-profile correction plus a semi-analytic model matches dedicated N-body suites for Ω_m and σ_8 inference at a fraction of the cost.
-
Void spin distribution as a powerful probe of $\sigma_{8}$
Void spin distributions, fitted by a generalized Gamma function, are shown in simulations to vary sensitively with sigma8 but not with Omega_cdm h^2, neutrino mass, or dark energy equation of state, offering a new deg...
-
Vortices and rotating solitons in ultralight dark matter
Rotating solitons in self-interacting ultralight dark matter form through a uniform vortex lattice, with a maximum radius about 1.59 times and a maximum rotation rate about 1.34 times the square root of the central density.
-
MSA-3D: Rotation Curves and Dark Matter Fractions at z~0.5-1.7 with JWST/NIRSpec
New JWST data on 23 galaxies at 0.5<z<1.7 show median dark matter fraction of 0.63 at effective radius with 0.2 dex scatter, and a mix of rising, flat, and falling rotation curves.
-
Bulgeless Evolution And the Rise of Discs (BEARD) III. A numerical simulation view of satellites around Milky-Way analogues
Simulation comparison finds bulgeless galaxies host more centrally concentrated, disc-aligned satellites with steeper faint-end luminosity functions than bulge-dominated controls, reflecting co-evolution and quieter m...
-
Bulgeless Evolution And the Rise of Discs (BEARD) I. Physical drivers of the mass-size relation for Milky Way-like galaxies
Bulgeless galaxies trace the upper envelope of the mass-R1 relation with scatter driven by central stellar density and the spatial configuration of mergers rather than their number.
Discussion (0). Continue with ORCID to comment.