_{1}

^{*}

Collisionless dark matter can only expand adiabatically. To test this idea and constrain the properties of dark matter, we study spiral galaxies in the “Spitzer Photometry and Accurate Rotation Curves” (SPARC) sample. Fitting the rotation curves, we obtain the root-mean-square (rms) velocity and density of dark matter in the core of the galaxies. We then calculate the rms velocity
*v*_{hrms} (1) that dark matter particles would have if expanded adiabatically from the core of the galaxies to the present mean density of dark matter in the universe. We obtain this “adiabatic invariant”
*v*
_{hrms} (1) for 40 spiral galaxies. The distribution of
*v*
_{hrms} (1) has a mean 0.87 km/s and a standard deviation of 0.27 km/s. This low relative dispersion is noteworthy given the wide range of the properties of these galaxies. The adiabatic invariant
*v*
_{hrms} (1) may, therefore, have a cosmological origin. In this case, the rms velocity of non-relativistic dark matter particles in the early universe when density perturbations are still linear is
*v*_{hrms} (*a*)=*v*_{hrms} (1)/*a*, where
*a* is the expansion parameter. The adiabatic invariant obtains the ratio of dark matter temperature
*T*
* _{h}* (a) to mass

*m*

_{h}in the early universe.

This is our motivation. Collisionless non-relativistic dark matter can only expand adiabatically conserving v h rms / ρ h 1 / 3 , where v h rms is the root-mean-square (rms) of the dark matter particle velocities, and ρ h is the density of dark matter. It turns out that we are able to measure v h rms / ρ h 1 / 3 in the core of spiral galaxies by fitting their rotation curves. In the early universe, when density perturbations are relatively small, v h rms ( a ) of non-relativistic dark matter can be written in the form

v h rms ( a ) = v h rms ( 1 ) a , (1)

and ρ h = Ω c ρ crit / a 3 , where a is the expansion parameter. Note that the expansion is adiabatic. Consider a free observer in a density peak. The dark matter in this peak expands, reaches maximum expansion, and then contracts forming a galaxy, conserving v h rms / ρ h 1 / 3 . Let 〈 v r h 2 〉 1 / 2 be the root-mean-square of the radial component of the dark matter particle velocities, and let ρ h ( r → 0 ) be the dark matter density in the core of the galaxy. Adiabatic expansion then implies that [

v h rms ( 1 ) ≡ 3 〈 v r h 2 〉 1 / 2 ( Ω c ρ crit ρ h ( r → 0 ) ) 1 / 3 . (2)

Note that v h rms ( 1 ) is, by definition, the rms velocity of dark matter particles when dark matter with density ρ h ( r → 0 ) in the core of the galaxy is expanded adiabatically until it acquires the present mean dark matter density of the universe Ω c ρ crit [

In this article, we present a study of the adiabatic invariant v h rms ( 1 ) of galaxies in the “Spitzer Photometry and Accurate Rotation Curves” (SPARC) sample [

We analyze the publicly available data of the SPARC galaxy sample [

In the present analysis, we study the 99 galaxies with high-quality rotation curves, i.e. galaxies with quality flag Q = 1. We further visually examine the galaxy rotation curves, in order to guarantee sufficient data points in the flat part (to constrain 〈 v r h 2 〉 1 / 2 ), and sufficient data points in the galaxy core (to constrain ρ h ( r → 0 ) ). We are interested in galaxies with a relaxed structure in a steady-state, and so, by visual inspection, remove galaxies with rotation curves with extraneous features that may indicate recent mergers, strong warps, or galaxies with multi-spin components.

The rotation velocity v tot ( r ) ≡ v ( r ) is by definition the velocity of a test particle in a circular orbit of radius r in the plane of the galaxy. v ( r ) has contributions from baryons (stars in the disk and bulge, and gas), and the halo of dark matter [

v ( r ) 2 = v b ( r ) 2 + v h ( r ) 2 , (3)

v b = | v gas | v gas + ϒ disk | V disk | V disk + ϒ bulge | V bulge | V bulge . (4)

V disk and V bulge are stellar contributions to the rotation velocity inferred from the 3.6 μm photometry assuming a stellar mass-to-light ratio 1 M ⊙ / L ⊙ . The mass-to-light ratios of stars in the disk and bulge in units of M ⊙ / L ⊙ are taken to be ϒ disk ≡ ϒ * and ϒ bulge = 1.4 ϒ * respectively [

Examples of spiral galaxy rotation curves are presented in Figures 1-3. The flat rotation velocity v ( r ) at large r determines 〈 v r h 2 〉 / ( 1 − κ h ) = v flat 2 / 2 . The slopes of v ( r ) and v b ( r ) at small r determine

ρ h ( r → 0 ) = 3 [ v ( r ) 2 − v b ( r ) 2 ] / ( 4 π G r 2 ) .

κ h is a correction to account for possible dark matter rotation.

To take full advantage of the measured rotation curves, we integrate differential equations describing two self-gravitating non-relativistic gases: baryons and dark matter, see Reference [

a χ 2 between the measured rotation curves v ( r ) and v b ( r ) , and the corresponding calculated rotation curves. The calculated rotation curves are presented in Figures 1-3 with continuous lines. Note that good fits are obtained with 〈 v r h 2 〉 ′ and 〈 v r b 2 〉 ′ taken to be independent of r. A core correction Δ ρ h = ρ h ( r → 0 ) − ρ h ( r min ) is obtained by extrapolation.

In Reference [

The χ 2 of the fits requires the assignment of uncertainties to v ( r ) and v b ( r ) . The uncertainties of the v ( r ) measurements are given by the SPARC data. We generally assign Δ v b ( r ) = ± 3 km / s to cover point-to-point fluctuations (this may vary in some galaxies), plus a term ( ϒ * − 0.4 ) 2 / 0.15 2 in the χ 2 to allow for coherent fluctuations of v b ( r ) . The fit is accepted only if the fitted ϒ * lies in the range from 0.2 to 0.5. We set m h to some large value, e.g. 500 eV, to avoid the onset of Fermi-Dirac or Bose-Einstein degeneracy [

Additionally we perform fits with fixed ϒ * = 0.5 and ϒ * = 0.2 . Finally, we perform a fit for fermions with N f = 2 degrees of freedom, m h = 53.5 eV corresponding to chemical potential μ ≈ 0 [

For comparison, in

Note that fluctuations of the measured v h rms ( 1 ) are expected from irregularities of the rotation curves (for example, see Figures 1-3), as well as due to dark matter rotation, and statistical uncertainties.

The galaxies listed in

We consider the case of dark matter that decouples from the Standard Model sector and from self-annihilation while density perturbations are still linear. We neglect interactions of non-relativistic dark matter particles, except for gravity, or elastic dark matter-dark matter collisions. A non-relativistic gas of non-interacting particles can only expand or contract adiabatically conserving v h rms / ρ h 1 / 3 . When dark matter particles are non-relativistic, and density perturbations are still linear, the rms velocity of dark matter particles in the expanding universe has the form

v h rms ( a ) = v h rms ( 1 ) a , (5)

with v h rms ( 1 ) given by Equation (2). In conclusion, if dark matter decouples while density perturbations are still linear, then the adiabatic invariant v h rms ( 1 ) given by Equation (2) should be the same for all relaxed, steady-state galaxies, independently of their history of hierarchical formation and mergers (except for a correction due to dark matter rotation).

Consider a galaxy with v flat = 300 km / s . From the adiabatic invariant, the dark matter density in the core of this galaxy is approximately 8 × 10^{7} times the mean dark matter density of the universe. What stopped the dark matter collapse

Galaxy selection | N | Mean v h rms ( 1 ) | Std. dev. |
---|---|---|---|

[km/s] | [km/s] | ||

All | 40 | 0.866 | 0.273 |

L 3.6 < 1 × 10 9 L ⊙ | 11 | 0.838 | 0.297 |

L 3.6 > 4 × 10 9 L ⊙ | 11 | 1.036 | 0.192 |

M H I < 1 × 10 9 M ⊙ | 17 | 0.714 | 0.239 |

〈 v r h 2 〉 1 / 2 < 50 km / s | 17 | 0.786 | 0.259 |

〈 v r h 2 〉 1 / 2 > 60 km / s | 16 | 0.969 | 0.227 |

de Vaucouleurs class 5, 6 or 7 | 15 | 0.820 | 0.277 |

de Vaucouleurs class 9 or 10 | 18 | 0.869 | 0.258 |

SBdisk < 100 × 10 9 L ⊙ / pc 2 | 10 | 0.843 | 0.174 |

ρ h ( 0 ) > ρ b ( 0 ) | 37 | 0.842 | 0.255 |

from reaching infinite density? Why a core and not a cusp? We consider three alternatives:

1) The collapse is ongoing. Then the distribution of v h rms ( 1 ) would be very wide contrary to observation.

2) If v h rms ( 1 ) is of cosmological origin, i.e. if v h rms ( 1 ) is the same for all relaxed, steady-state galaxies, then a galaxy with a given v flat = 2 〈 v r h 2 〉 1 / 2 , has a well defined dark matter density in the core ρ h ( r → 0 ) given by Equation (2).

3) Fermi-Dirac degeneracy of fermion dark matter may halt the collapse.

Note that v h rms ( a ) in Equation (5) obtains the ratio of dark matter temperature T h ( a ) to mass m h in the early universe. To obtain the mass m h and temperature T h ( a ) separately, one more relation is needed, for example, the chemical potential μ of dark matter [

We have obtained the adiabatic invariant v h rms ( 1 ) of 40 galaxies in the SPARC sample. The distribution of v h rms ( 1 ) has a mean 0.87 km/s and a standard deviation of 0.27 km/s for relaxed galaxies with properties in wide ranges. This small relative standard deviation suggests a cosmological origin of v h rms ( 1 ) . If so, non-relativistic dark matter in the early universe, when density perturbations are still linear, satisfies

v h rms ( a ) = v h rms ( 1 ) a = 3 k T h ( a ) m h . (6)

In summary, the adiabatic invariant v h rms ( 1 ) obtains the ratio of dark matter temperature T h ( a ) to mass m h in the early universe. Note that temperature can be assigned to dark matter because it satisfies the Boltzmann distribution [

The author declares no conflicts of interest regarding the publication of this paper.

Hoeneisen, B. (2019) The Adiabatic Invariant of Dark Matter in Spiral Galaxies. International Journal of Astronomy and Astrophysics, 9, 355-367. https://doi.org/10.4236/ijaa.2019.94025

Galaxy | 〈 v r h 2 〉 ′ 1 / 2 | 〈 v r b 2 〉 ′ 1 / 2 | ρ h ( r min ) | ρ b ( r min ) | r min | Δ ρ h |
---|---|---|---|---|---|---|

[km/s] | [km/s] | [ 10 − 2 M ⊙ ⋅ pc − 3 ] | [ 10 − 2 M ⊙ ⋅ pc − 3 ] | [kpc] | [same] | |

D631-7 | 49.8 ± 4.4 | 21.2 ± 1.1 | 1.04 ± 0.12 | 1.59 ± 0.39 | 0.45 | 0.00 ± 0.00 |

DDO064 | 34.9 ± 5.8 | 40.8 ± 9.3 | 4.49 ± 1.23 | 1.13 ± 0.37 | 0.10 | 0.00 ± 0.00 |

DDO161 | 48.7 ± 1.5 | 32.5 ± 1.1 | 0.62 ± 0.05 | 0.76 ± 0.15 | 0.60 | 0.00 ± 0.00 |

ESO116 | ||||||

-G012 | 73.9 ± 3.7 | 57.4 ± 3.9 | 6.26 ± 1.32 | 3.71 ± 1.94 | 0.25 | 0.00 ± 0.00 |

F563-1 | 66.7 ± 2.2 | 83.9 ± 7.2 | 4.62 ± 0.81 | 0.21 ± 0.07 | 1.07 | 0.50 ± 0.50 |

F563-V2* | 72.8 ± 4.4 | 85.0 ± 7.5 | 10.88 ± 2.65 | 1.11 ± 0.28 | 0.28 | 0.00 ± 0.00 |

F568-1 | 80.3 ± 3.5 | 190.5 ± 86.3 | 7.12 ± 1.44 | 0.16 ± 0.08 | 0.44 | 0.00 ± 0.00 |

F568-3 | 68.0 ± 3.2 | 79.7 ± 10.2 | 2.05 ± 0.22 | 0.25 ± 0.13 | 0.64 | 0.00 ± 0.00 |

F568-V1 | 70.1 ± 3.1 | 88.2 ± 14.8 | 9.44 ± 2.02 | 0.42 ± 0.37 | 0.39 | 0.00 ± 0.00 |

F571-8* | 99.9 ± 2.7 | 40.6 ± 1.0 | 4.44 ± 0.42 | 14.60 ± 2.08 | 0.22 | 0.00 ± 0.00 |

F574-1* | 60.0 ± 1.4 | 65.8 ± 3.3 | 4.52 ± 0.61 | 0.75 ± 0.11 | 0.47 | 0.00 ± 0.00 |

F579-V1 | 69.5 ± 2.3 | 87.7 ± 6.2 | 21.17 ± 5.36 | 1.28 ± 0.77 | 0.42 | 2.00 ± 1.00 |

F583-1 | 51.5 ± 2.1 | 99.5 ± 20.8 | 2.21 ± 0.22 | 0.09 ± 0.03 | 0.26 | 0.00 ± 0.00 |

F583-4 | 40.4 ± 2.1 | 38.2 ± 4.1 | 4.18 ± 1.58 | 1.18 ± 0.58 | 0.22 | 0.10 ± 0.10 |

NGC0024 | 71.3 ± 1.1 | 66.5 ± 3.1 | 35.49 ± 4.46 | 6.03 ± 2.99 | 0.21 | 1.00 ± 1.00 |

NGC0100 | 60.7 ± 4.2 | 40.9 ± 1.9 | 2.71 ± 0.59 | 2.22 ± 0.85 | 0.23 | 0.00 ± 0.00 |

NGC3109 | 46.1 ± 1.8 | 34.7 ± 3.2 | 1.88 ± 0.14 | 0.42 ± 0.10 | 0.26 | 0.00 ± 0.00 |

NGC3972 | 83.2 ± 3.3 | 86.4 ± 8.1 | 7.08 ± 1.40 | 1.37 ± 0.92 | 0.87 | 0.80 ± 0.60 |

NGC4183 | 71.2 ± 1.1 | 72.2 ± 3.3 | 5.22 ± 0.72 | 1.05 ± 0.35 | 0.87 | 0.70 ± 0.70 |

NGC4559* | 91.0 ± 2.3 | 66.1 ± 1.0 | 2.59 ± 0.36 | 7.82 ± 0.48 | 0.67 | 0.20 ± 0.20 |

NGC6503 | 83.9 ± 0.6 | 64.1 ± 0.6 | 18.66 ± 0.97 | 23.58 ± 2.86 | 0.76 | 5.50 ± 5.50 |

UGC00731 | 43.1 ± 1.0 | 106.1 ± 32.6 | 3.02 ± 0.37 | 0.13 ± 0.03 | 0.91 | 0.50 ± 0.50 |

UGC01230 | 68.6 ± 2.8 | 75.5 ± 4.2 | 4.18 ± 1.00 | 0.60 ± 0.22 | 0.78 | 0.30 ± 0.30 |

UGC01281 | 39.7 ± 3.0 | 36.9 ± 4.5 | 2.33 ± 0.35 | 0.56 ± 0.15 | 0.08 | 0.00 ± 0.00 |

UGC04325 | 55.9 ± 1.4 | 70.7 ± 6.6 | 16.85 ± 2.09 | 1.90 ± 0.73 | 0.70 | 4.00 ± 4.00 |

UGC04499 | 45.8 ± 2.0 | 48.6 ± 5.0 | 2.91 ± 0.52 | 0.85 ± 0.29 | 0.91 | 0.50 ± 0.50 |

UGC05005* | 61.6 ± 3.9 | 62.7 ± 4.1 | 0.76 ± 0.18 | 0.14 ± 0.02 | 0.78 | 0.00 ± 0.00 |

UGC05750 | 50.1 ± 5.9 | 55.5 ± 5.6 | 0.65 ± 0.13 | 0.14 ± 0.05 | 1.47 | 0.05 ± 0.05 |

UGC06399 | 55.5 ± 3.3 | 54.8 ± 5.9 | 3.46 ± 0.70 | 0.76 ± 0.32 | 0.87 | 0.40 ± 0.30 |

Galaxy | 〈 v r h 2 〉 ′ 1 / 2 | 〈 v r b 2 〉 ′ 1 / 2 | ρ h ( r min ) | ρ b ( r min ) | r min | Δ ρ h |
---|---|---|---|---|---|---|

[km/s] | [km/s] | [ 10 − 2 M ⊙ ⋅ pc − 3 ] | [ 10 − 2 M ⊙ ⋅ pc − 3 ] | [kpc] | [same] | |

UGC06446 | 50.0 ± 1.1 | 64.8 ± 6.9 | 8.11 ± 1.22 | 0.64 ± 0.26 | 0.58 | 1.15 ± 1.00 |

UGC06667 | 53.6 ± 1.7 | 82.4 ± 18.2 | 3.89 ± 0.44 | 0.21 ± 0.06 | 0.87 | 0.50 ± 0.40 |

UGC06917 | 67.3 ± 2.8 | 75.9 ± 8.2 | 3.54 ± 0.56 | 0.68 ± 0.31 | 1.74 | 1.05 ± 0.90 |

UGC06930 | 67.7 ± 2.7 | 74.0 ± 5.6 | 2.91 ± 0.68 | 0.66 ± 0.25 | 1.74 | 0.70 ± 0.70 |

UGC07125 | 38.6 ± 1.4 | 47.8 ± 5.4 | 0.83 ± 0.17 | 0.22 ± 0.09 | 1.44 | 0.15 ± 0.15 |

UGC07151 | 43.3 ± 1.3 | 52.2 ± 6.9 | 11.07 ± 1.95 | 2.07 ± 1.29 | 0.50 | 2.00 ± 2.00 |

UGC07323 | 62.6 ± 8.8 | 56.6 ± 8.7 | 2.38 ± 0.73 | 1.20 ± 0.63 | 0.58 | 0.10 ± 0.10 |

UGC07399 | 63.2 ± 1.5 | 62.3 ± 5.8 | 18.63 ± 1.98 | 2.11 ± 0.92 | 0.61 | 4.25 ± 4.00 |

UGC07524 | 47.6 ± 0.8 | 79.1 ± 15.0 | 2.71 ± 0.22 | 0.19 ± 0.08 | 0.35 | 0.05 ± 0.05 |

UGC07603 | 41.4 ± 1.6 | 32.4 ± 2.8 | 11.12 ± 1.75 | 4.07 ± 1.72 | 0.34 | 1.00 ± 1.00 |

UGC07608 | 42.9 ± 5.6 | 63.7 ± 25.2 | 3.88 ± 1.25 | 0.31 ± 0.13 | 0.60 | 0.30 ± 0.30 |

UGC08286 | 51.4 ± 0.8 | 56.3 ± 6.8 | 11.09 ± 1.27 | 1.25 ± 0.78 | 0.47 | 1.50 ± 1.50 |

UGC08490 | 53.4 ± 0.9 | 45.1 ± 1.9 | 22.02 ± 2.98 | 10.43 ± 3.91 | 0.34 | 4.00 ± 4.00 |

UGC10310 | 43.1 ± 2.9 | 56.6 ± 8.5 | 4.05 ± 1.17 | 0.68 ± 0.30 | 1.10 | 1.00 ± 1.00 |

UGC11914* | 197.8 ± 0.7 | 188.1 ± 1.1 | 526.8 ± 17.3 | 421.0 ± 11.1 | 0.28 | 165 ± 165 |

UGC12632 | 43.3 ± 1.0 | 63.4 ± 10.7 | 3.03 ± 0.40 | 0.25 ± 0.11 | 0.71 | 0.40 ± 0.40 |

UGCA442 | 38.0 ± 1.0 | 28.7 ± 2.3 | 2.66 ± 0.32 | 1.23 ± 0.34 | 0.42 | 0.20 ± 0.20 |

Galaxy | Fitted | v h rms ( 1 ) | v h rms ( 1 ) | v h rms ( 1 ) | v h rms ( 1 ) |
---|---|---|---|---|---|

ϒ * | [km/s] | ϒ * = 0.5 | ϒ * = 0.2 | m h = 53.5 eV | |

D631-7 | 0.32 ± 0.14 | 1.27 ± 0.16 | 1.30 ± 0.18 | 1.19 ± 0.15 | 0.99 ± 0.16 |

DDO064 | 0.44 ± 0.14 | 0.55 ± 0.14 | 0.59 ± 0.16 | n.a. | 0.66 ± 0.09 |

DDO161 | 0.29 ± 0.14 | 1.47 ± 0.09 | 1.54 ± 0.09 | 1.44 ± 0.08 | 1.40 ± 0.09 |

ESO116-G012 | 0.42 ± 0.17 | 1.03 ± 0.13 | 1.10 ± 0.07 | 0.91 ± 0.04 | 0.77 ± 0.07 |

F563-1 | 0.33 ± 0.14 | 1.00 ± 0.10 | 1.01 ± 0.11 | 1.00 ± 0.10 | 0.83 ± 0.09 |

F563-V2 | n.a. | n.a. | 0.85 ± 0.12 | 0.83 ± 0.11 | n.a. |

F568-1 | 0.19 ± 0.09 | 1.08 ± 0.12 | 1.04 ± 0.12 | 1.07 ± 0.12 | 0.84 ± 0.09 |

F568-3 | 0.28 ± 0.13 | 1.38 ± 0.11 | 1.43 ± 0.12 | 1.36 ± 0.10 | 1.20 ± 0.13 |

F568-V1 | 0.30 ± 0.19 | 0.86 ± 0.10 | 0.84 ± 0.10 | 0.87 ± 0.10 | 0.68 ± 0.06 |

F571-8 | n.a. | n.a. | n.a. | 1.57 ± 0.09 | n.a. |

F574-1 | n.a. | n.a. | 0.94 ± 0.06 | 0.91 ± 0.06 | n.a. |

F579-V1 | 0.28 ± 0.14 | 0.63 ± 0.07 | 0.64 ± 0.08 | 0.63 ± 0.07 | 0.57 ± 0.04 |

F583-1 | 0.27 ± 0.08 | 1.02 ± 0.08 | 1.03 ± 0.08 | 1.01 ± 0.07 | 0.83 ± 0.05 |
---|---|---|---|---|---|

F583-4 | 0.40 ± 0.15 | 0.64 ± 0.12 | 0.67 ± 0.13 | 0.60 ± 0.09 | 0.66 ± 0.09 |

NGC0024 | 0.26 ± 0.13 | 0.55 ± 0.03 | 0.60 ± 0.03 | 0.54 ± 0.02 | 0.54 ± 0.03 |

NGC0100 | 0.43 ± 0.13 | 1.12 ± 0.16 | 1.19 ± 0.11 | 0.94 ± 0.06 | 0.84 ± 0.12 |

NGC3109 | 0.40 ± 0.15 | 0.96 ± 0.06 | 0.98 ± 0.06 | 0.94 ± 0.05 | 0.81 ± 0.03 |

NGC3972 | 0.22 ± 0.14 | 1.08 ± 0.12 | 1.22 ± 0.16 | 1.07 ± 0.10 | 0.79 ± 0.07 |

NGC4183 | 0.20 ± 0.08 | 1.01 ± 0.08 | 1.16 ± 0.11 | 1.01 ± 0.07 | 0.91 ± 0.09 |

NGC4559 | n.a. | n.a. | 1.67 ± 0.13 | 1.07 ± 0.05 | 1.77 ± 0.21 |

NGC6503 | 0.29 ± 0.03 | 0.75 ± 0.09 | 0.83 ± 0.12 | 0.72 ± 0.07 | 0.77 ± 0.12 |

UGC00731 | 0.42 ± 0.14 | 0.73 ± 0.07 | 0.73 ± 0.07 | 0.73 ± 0.07 | 0.63 ± 0.05 |

UGC01230 | 0.41 ± 0.14 | 1.07 ± 0.13 | 1.08 ± 0.13 | 1.07 ± 0.14 | 0.99 ± 0.13 |

UGC01281 | 0.48 ± 0.12 | 0.77 ± 0.10 | 0.78 ± 0.10 | n.a. | n.a. |

UGC04325 | 0.38 ± 0.15 | 0.52 ± 0.06 | 0.53 ± 0.06 | 0.52 ± 0.06 | 0.46 ± 0.08 |

UGC04499 | 0.40 ± 0.15 | 0.78 ± 0.10 | 0.81 ± 0.10 | 0.75 ± 0.08 | 0.66 ± 0.07 |

UGC05005 | n.a. | n.a. | 1.85 ± 0.30 | 1.74 ± 0.25 | n.a. |

UGC05750 | 0.38 ± 0.14 | 1.45 ± 0.27 | 1.50 ± 0.28 | 1.39 ± 0.25 | 1.28 ± 0.30 |

UGC06399 | 0.39 ± 0.15 | 0.91 ± 0.12 | 0.94 ± 0.13 | 0.87 ± 0.10 | 0.74 ± 0.07 |

Galaxy | Fitted | v h rms ( 1 ) | v h rms ( 1 ) | v h rms ( 1 ) | v h rms ( 1 ) |
---|---|---|---|---|---|

ϒ * | [km/s] | ϒ * = 0.5 | ϒ * = 0.2 | m h = 53.5 eV | |

UGC06446 | 0.35 ± 0.14 | 0.61 ± 0.05 | 0.62 ± 0.06 | 0.61 ± 0.05 | 0.57 ± 0.04 |

UGC06667 | 0.44 ± 0.14 | 0.84 ± 0.07 | 0.84 ± 0.07 | 0.84 ± 0.07 | 0.71 ± 0.04 |

UGC06917 | 0.40 ± 0.15 | 1.04 ± 0.15 | 1.07 ± 0.16 | 1.01 ± 0.12 | 0.85 ± 0.12 |

UGC06930 | 0.37 ± 0.14 | 1.14 ± 0.17 | 1.18 ± 0.19 | 1.09 ± 0.14 | 1.03 ± 0.18 |

UGC07125 | 0.32 ± 0.15 | 1.00 ± 0.13 | 1.08 ± 0.15 | 0.96 ± 0.10 | 0.75 ± 0.08 |

UGC07151 | 0.31 ± 0.16 | 0.47 ± 0.05 | 0.50 ± 0.06 | 0.46 ± 0.04 | 0.55 ± 0.10 |

UGC07323 | 0.36 ± 0.15 | 1.19 ± 0.29 | 1.40 ± 0.35 | 1.05 ± 0.15 | 0.85 ± 0.14 |

UGC07399 | 0.37 ± 0.15 | 0.57 ± 0.06 | 0.58 ± 0.06 | 0.56 ± 0.06 | 0.54 ± 0.06 |

UGC07524 | 0.21 ± 0.11 | 0.87 ± 0.04 | 0.90 ± 0.04 | 0.87 ± 0.04 | 0.71 ± 0.03 |

UGC07603 | 0.40 ± 0.14 | 0.47 ± 0.05 | 0.48 ± 0.04 | 0.44 ± 0.03 | 0.52 ± 0.31 |

UGC07608 | 0.39 ± 0.15 | 0.69 ± 0.17 | 0.69 ± 0.17 | 0.68 ± 0.16 | 0.68 ± 0.12 |

UGC08286 | 0.35 ± 0.18 | 0.57 ± 0.04 | 0.59 ± 0.04 | 0.55 ± 0.03 | 0.55 ± 0.04 |

UGC08490 | 0.47 ± 0.14 | 0.47 ± 0.04 | 0.47 ± 0.04 | 0.43 ± 0.03 | 0.44 ± 0.04 |

UGC10310 | 0.40 ± 0.15 | 0.65 ± 0.13 | 0.66 ± 0.13 | 0.63 ± 0.11 | 0.55 ± 0.11 |

UGC11914* | n.a. | n.a. | n.a. | 0.58 ± 0.06 | n.a. |

UGC12632 | 0.36 ± 0.16 | 0.74 ± 0.06 | 0.75 ± 0.07 | 0.73 ± 0.06 | 0.62 ± 0.04 |

UGCA442 | 0.40 ± 0.15 | 0.69 ± 0.05 | 0.69 ± 0.05 | 0.68 ± 0.05 | 0.56 ± 0.04 |