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Evidence for large baryonic feedback at low and intermediate redshifts from kinematic Sunyaev-Zel\u27dovich observations with ACT and DESI photometric galaxies
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The Mother of All Tableaux: Order, Equivalence, and Geometry in the Largescale Structure of Optimality Theory [book review]
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Measuring Bar and Spiral Arm Pattern Speeds in MaNGA Barred Spiral Galaxies
No full textWe measure independent pattern speeds for bar and spiral arms in 98 barred spiral galaxies with Mapping Nearby Galaxies at Apache Point Observatory data. Some galaxies exhibit statistically different pattern speeds (Ωbar ≠ Ωspiral), while others have statistically equal pattern speeds. We find no trends of ΔΩ with stellar mass or galaxy color. Our results are consistent with a Universe which might have some bar-driven spirals (ΔΩ = 0), but some spirals in barred galaxies must be tidally driven or self-excited (ΔΩ ≠ 0). These results demonstrate the potential for ΔΩ measurements to constrain spiral arm formation mechanisms
Fuzzy dark matter constraints from the Hubble Frontier Fields
No full textIn fuzzy dark matter (FDM) cosmologies, the dark matter consists of ultralight bosons (m≲10−20 eV). The astrophysically large de Broglie wavelengths of such particles hinder the formation of low-mass dark matter haloes. This implies a testable prediction: a corresponding suppression in the faint end of the ultraviolet luminosity function (UVLF) of galaxies. Notably, recent estimates of the faint-end UVLF at z∼5−9 in the Hubble Frontier Fields, behind foreground lensing clusters, probe up to five magnitudes fainter than typical (‘blank-field’) regions. These measurements thus far disfavour prominent turnovers in the UVLF at low luminosity, implying bounds on FDM. We fit a semi-empirical model to these and blank-field UVLF data, including the FDM particle mass as a free parameter. This fit excludes cases where the dark matter is entirely a boson of mass m\u3c 1.5×10−21 eV (with 2σ confidence). We also present a less stringent bound deriving solely from the requirement that the total observed abundance of galaxies, integrated over all luminosities, must not exceed the total halo abundance in FDM. This more model-agnostic bound disfavours m\u3c 5×10−22 eV (2σ). We forecast that future UVLF measurements from JWST lensing fields may probe masses several times larger than these bounds, although we demonstrate this is subject to theoretical uncertainties in modelling the FDM halo mass function
