Cold Dark Matter (CDM) models struggle to match the observations at galactic scales. The tension can be reduced either by dramatic baryonic feedback effects or by modifying the particle physics of ...CDM. Here, we consider an ultra-light scalar field DM particle manifesting a wave nature below a DM particle mass-dependent Jeans scale. For DM mass m ∼ 10−22 eV, this scenario delays galaxy formation and avoids cusps in the centre of the dark matter haloes. We use new measurements of half-light mass in ultra-faint dwarf galaxies Draco II and Triangulum II to estimate the mass of the DM particle in this model. We find that if the stellar populations are within the core of the density profile then the data are in agreement with a Wave Dark Matter model having a DM particle with m ∼ 3.7–5.6 × 10−22 eV. The presence of this extremely light particle will contribute to the formation of a central solitonic core replacing the cusp of a Navarro–Frenk–White profile and bringing predictions closer to observations of cored central density in dwarf galaxies.
Abstract We present fluxes and light curves for a population of asteroids at millimeter wavelengths, detected by the Atacama Cosmology Telescope (ACT) over 18,000 deg 2 of the sky using data from ...2017 to 2021. We utilize high cadence maps, which can be used in searching for moving objects such as asteroids and trans-Neptunian Objects, as well as for studying transients. We detect 170 asteroids with a signal-to-noise of at least 5 in at least one of the ACT observing bands, which are centered near 90, 150, and 220 GHz. For each asteroid, we compare the ACT measured flux to predicted fluxes from the near-Earth asteroid thermal model fit to WISE data. We confirm previous results that detected a deficit of flux at millimeter wavelengths. Moreover, we report a spectral characteristic to this deficit, such that the flux is relatively lower at 150 and 220 GHz than at 90 GHz. Additionally, we find that the deficit in flux is greater for S-type asteroids than for C-type.
Political Shiisms Beaumont, Robin; Calabrese, Erminia Chiara
Revue des mondes musulmans et de la Méditerranée,
2021, Letnik:
145
Journal Article
Recenzirano
Odprti dostop
Among the many scholarly and popular discourses that proliferated with the advent of the third millennium and which took on new intensity, particularly since 2012, on the confessional polarization of ...the Arab world and intensification of transnational conflict between Sunni and Shia Islam, a certain geohistorical narrative appears to be emerging at the regional and particularly Middle Eastern level which would symmetrically oppose the fragmentation of Sunni Islam to the rise of a unified Shii...
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