Friday.
1605.01414
Wavelet reconstruction of E and B modes for CMB polarization and cosmic shear analyses
Listed, McEwen, Büttner, Peiris
Present new methods for mapping the curl-free (E-mode) and divergence-free (B-mode) components of spin 2 signals using spin directional wavelets. The methods are equally applicable to measurements of the polarization of the CMB and the shear of galaxy shapes due to WL. Derive pseudo and pure wavelet estimators, where E-B mixing arising due to incomplete sky coverage is suppressed in wavelet space using scale- and orientation-dependent masking and weighting schemes. In the case of the pure estimator, ambiguous modes (which have vanishing curl and divergence simultaneously on the incomplete sky) are also cancelled. On simulations, demonstrate the improvement (i.e., reduction in leakage) provided by the wavelet space estimators over standard harmonic space approaches. The new methods can be directly interfaced in a coherent and computationally-efficient manner with component separation or feature extraction techniques that also exploit wavelets.
1605.01489
New lessons from the HI size-mass relation of galaxies
Wang, et al
Revisit the HI size-mass (D_HI-M_HI) relation of galaxies with a sample of >500 nearby galaxies covering over 5 orders of magnitude in HI mass and more than 10 B-band magnitudes. The relation is remarkably tight with a scatter sigma~0.06 dex, or 14%. The scatter does not change as a function of galaxy luminosity, HI richness or morphological type. The relation is linked to the fact that dwarf and spiral galaxies have a homogeneous radial profile of HI surface density in the outer regions when the radius is normalized by D_HI. The early-type disk galaxies typically have shallower HI radial profiles, indicating a different gas accretion history. Argue that the process of atomic-to-molecular gas conversion of SF cannot explain the tightness of the D_HI-M_HI relation. This simple relation puts strong constraints on simulation models for galaxy formation.
1605.01414
Wavelet reconstruction of E and B modes for CMB polarization and cosmic shear analyses
Listed, McEwen, Büttner, Peiris
Present new methods for mapping the curl-free (E-mode) and divergence-free (B-mode) components of spin 2 signals using spin directional wavelets. The methods are equally applicable to measurements of the polarization of the CMB and the shear of galaxy shapes due to WL. Derive pseudo and pure wavelet estimators, where E-B mixing arising due to incomplete sky coverage is suppressed in wavelet space using scale- and orientation-dependent masking and weighting schemes. In the case of the pure estimator, ambiguous modes (which have vanishing curl and divergence simultaneously on the incomplete sky) are also cancelled. On simulations, demonstrate the improvement (i.e., reduction in leakage) provided by the wavelet space estimators over standard harmonic space approaches. The new methods can be directly interfaced in a coherent and computationally-efficient manner with component separation or feature extraction techniques that also exploit wavelets.
1605.01489
New lessons from the HI size-mass relation of galaxies
Wang, et al
Revisit the HI size-mass (D_HI-M_HI) relation of galaxies with a sample of >500 nearby galaxies covering over 5 orders of magnitude in HI mass and more than 10 B-band magnitudes. The relation is remarkably tight with a scatter sigma~0.06 dex, or 14%. The scatter does not change as a function of galaxy luminosity, HI richness or morphological type. The relation is linked to the fact that dwarf and spiral galaxies have a homogeneous radial profile of HI surface density in the outer regions when the radius is normalized by D_HI. The early-type disk galaxies typically have shallower HI radial profiles, indicating a different gas accretion history. Argue that the process of atomic-to-molecular gas conversion of SF cannot explain the tightness of the D_HI-M_HI relation. This simple relation puts strong constraints on simulation models for galaxy formation.
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