DWARFS IN HIPASS AND SDSS

DWARFS IN HIPASS AND SDSS

Their properties merge smoothly with giants and show no extra

Dark Matter

HOW MUCH GLOBAL INFORMATION/ GALAXY?

• HOW MANY PHYSICAL PARAMETERS COULD CONTROL GALAXIES?

• Total Mass, Baryon fract, Ang Mom,Radius, Concentration,Gas Mass,Age; ie SEVEN LESS 1 for Virial Theorem. Therefore SIX physical params.

• HOW MANY INDEPENDENT OBSERVABLES CAN BE MEASURED?

• Eg Lum, Radius, Concentration, M(HI), Internal Vel disp, Colour ……ie SIX too.

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ΔV( )2

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ΔV( )2

Dwarfs v ClustersGilmore et al 2007

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M/L ratios in Dwarfs Gilmore 2007

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Montage of ES galaxies

SB v Col Density

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HOW MUCH INDEPENDENCE?

• We find 200 objects in HI Blind survey coincident with SDSS images and correlate all the following props:Lum, Colour, Radius,M(HI), R(90)/R(50), and M(dyn).

• Each indep correl must reduce 6 independent variables by 1.

• We find 5 correls (one new).Thus HI selected Galaxies form a ONE PARAMETER SET.

• This is confirmed by Principal Component Analysis.

Concentration v Mass

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HIMASS versus opt radius

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Colour v Luminosity

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Mass v Luminosity

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SB versus Luminosity

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Dynamical Mass v R(cubed)

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Correlation plot for 5 variables, not including colour

Principal Components for 5 variables, no colour

Correlations between 6 variables including colour

Principal components including colour

Simulation.2 variables correlated, the third is random

PCA of above. Note random varbl. has strong PC2

OBSERVE THE REAL SKY

• This high degree of organisation is totally inconsistent with Hierarchical galaxy Formation.(at least 4) and mergers.

• Galaxy astronomers should look at their observations free of prejudices drawn from cosmological simulations which look increasingly misleading!

• Observations of Galaxies contain far more reliable information about the process of Gal formation than numerical simulations.