316 research outputs found
Opposite role of different carbon fiber reinforcements on the non-isothermal crystallization behavior of poly(etheretherketone)
Characterization of thermally annealed PEEK and CFR-PEEK composites: Structure-properties relationships
MALTODEXTRIN-BASED ELECTROSPUN MAT AS ADSORBENTS FOR THE REMOVAL OF ATENOLOL AS EMERGING POLLUTANTS FROM WATER
The Orion-Taurus ridge: a synchrotron radio loop at the edge of the Orion-Eridanus superbubble
Large-scale synchrotron loops are recognized as the main source of diffuse
radio-continuum emission in the Galaxy at intermediate and high Galactic
latitudes. Their origin, however, remains rather unexplained. Using a
combination of multi-frequency data in the radio band of total and polarized
intensities, for the first time in this letter, we associate one arc --
hereafter, the Orion-Taurus ridge -- with the wall of the most prominent
stellar-feedback blown shell in the Solar neighborhood, namely the
Orion-Eridanus superbubble. We traced the Orion-Taurus ridge using 3D maps of
interstellar dust extinction and column-density maps of molecular gas, . We found the Orion-Taurus ridge at a distance of 400\,pc, with a
plane-of-the-sky extent of \,pc. Its median value is
cm. Thanks to the broadband
observations below 100 MHz of the Long Wavelength Array, we also computed the
low-frequency spectral-index map of synchrotron emissivity, , in the
Orion-Taurus ridge. We found a flat distribution of with a median value
of that we interpreted in terms of depletion of
low-energy ( GeV) cosmic-ray electrons in recent supernova remnants (
- yrs). Our results are consistent with plane-of-the-sky magnetic-field
strengths in the Orion-Taurus ridge larger than a few tens of G (G). We report the first detection of diffuse synchrotron emission from
cold-neutral, partly molecular, gas in the surroundings of the Orion-Eridanus
superbubble. This observation opens a new perspective to study the multiphase
and magnetized interstellar medium with the advent of future high-sensitivity
radio facilities, such as the C-Band All-Sky Survey and the Square Kilometre
Array.Comment: Accepted for publication in Astronomy & Astrophysic
Manganiakasakaite-(La) and Ferriakasakaite-(Ce), Two New Epidote Supergroup Minerals from Piedmont, Italy
Two new monoclinic (P21/m) epidote supergroup minerals manganiakasakaite-(La) and ferriakasakaite-(Ce) were found in the small Mn ore deposit of Monte Maniglia, Bellino, Varaita Valley, Cuneo Province, Piedmont, Italy. Manganiakasakaite-(La) occurs as subhedral grains embedded in pyroxmangite. Its empirical formula is A(1)(Ca0.62Mn2+0.38) A(2)(La0.52Nd0.08Pr0.07Ce0.07Y0.01Ca0.25) M(1)(Mn3+0.52Fe3+0.28Al0.18V3+0.01) M(2)Al1.00 M(3)(Mn2+0.60Mn3+0.27Mg0.13) T(1−3)(Si2.99Al0.01) O12 (OH), corresponding to the end-member formula CaLaMn3+AlMn2+(Si2O7)(SiO4)O(OH). Unit-cell parameters are a = 8.9057(10), b = 5.7294(6), c = 10.1134(11) Å, β = 113.713(5)°, V = 472.46(9) Å3, Z = 2. The crystal structure of manganiakasakaite-(La) was refined to a final R1 = 0.0262 for 2119 reflections with Fo > 4σ(Fo) and 125 refined parameters. Ferriakasakaite-(Ce) occurs as small homogeneous domains within strongly inhomogeneous prismatic crystals, where other epidote supergroup minerals coexist [manganiandrosite-(Ce), “androsite-(Ce)”, and epidote]. Associated minerals are calcite and hematite. Its empirical formula is A(1)(Ca0.64Mn2+0.36) A(2)(Ce0.37La0.17Nd0.06Pr0.03Ca0.35â–¡0.02) M(1)(Fe3+0.61Al0.39) M(2)Al1.00 M(3)(Mn2+0.64Mn3+0.33Fe3+0.02Mg0.01) T(1−3)Si3.01 O12 (OH), the end-member formula being CaCeFe3+AlMn2+(Si2O7)(SiO4)O(OH). Unit-cell parameters are a = 8.9033(3), b = 5.7066(2), c = 10.1363(3) Å, β = 114.222(2)°, V = 469.66(3) Å3, Z = 2. The crystal structure of ferriakasakaite-(Ce) was refined to a final R1 = 0.0196 for 1960 unique reflections with Fo > 4σ(Fo) and 124 refined parameters
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