Romanian Academy

About: Romanian Academy is a archive organization based out in Bucharest, Romania. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 3662 authors who have published 10491 publications receiving 146447 citations. The organization is also known as: Academia Română & Societatea Literară Română.

Galaxy And Mass Assembly (GAMA) : trends in galaxy colours, morphology, and stellar populations with large-scale structure, group, and pair environments

Abstract: We explore trends in galaxy properties with Mpc-scale structures using catalogues of environment and large-scale structure from the Galaxy And Mass Assembly (GAMA) survey. Existing GAMA catalogues of large-scale structure, group, and pair membership allow us to construct galaxy stellar mass functions for different environmental types. To avoid simply extracting the known underlying correlations between galaxy properties and stellar mass, we create a mass matched sample of galaxies with stellar masses within 9.5 ≤ log M*/h−2 M⊙ ≤ 11 for each environmental population. Using these samples, we show that mass normalized galaxies in different large-scale environments have similar energy outputs, u − r colours, luminosities, and morphologies. Extending our analysis to group and pair environments, we show that galaxies that are not in groups or pairs exhibit similar characteristics to each other regardless of broader environment. For our mass controlled sample, we fail to see a strong dependence of Sersic index or galaxy luminosity on halo mass, but do find that it correlates very strongly with colour. Repeating our analysis for galaxies that have not been mass controlled introduces and amplifies trends in the properties of galaxies in pairs, groups, and large-scale structure, indicating that stellar mass is the most important predictor of the galaxy properties we examine, as opposed to environmental classifications.

Toeplitz Operators on Symplectic Manifolds

Abstract: We study the Berezin-Toeplitz quantization on symplectic manifolds making use of the full off-diagonal asymptotic expansion of the Bergman kernel. We give also a characterization of Toeplitz operators in terms of their asymptotic expansion. The semi-classical limit properties of the Berezin-Toeplitz quantization for non-compact manifolds and orbifolds are also established.

Synthesis and Structural Characterization of Single-Phase BiFeO3 Powders from a Polymeric Precursor

Abstract: The present investigation reports on a simple technique for the preparation of single-phase BiFeO3 powders using the polymerized complex method, starting from iron and bismuth nitrates. A mixed aqueous solution with citric acid, ethylene glycol, Bi, and Fe ions was polymerized. The formation mechanism, the homogeneity, and the structure of the obtained powders have been investigated by thermogravimetry, X-ray diffraction (XRD), Raman spectroscopy, and scanning and transmission electron microscopy measurements. XRD results demonstrated that thermally induced crystallization of rhombohedral BiFeO3 from the Bi–Fe polymeric precursor occurred at temperatures as low as 400°C. Pure single-phase BiFeO3 nanocrystallites without any impurity or amorphous phases were obtained when the precursor was treated at 600°C for 3 h.