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Cold cores in interstellar molecular clouds represent the very first phase in star formation. The physical conditions of these objects are studied in order to understand how molecular clouds evolve and how stellar masses are determined. The purpose of this study is to probe conditions in the dense, starless clump Ophichus D (Oph D). The ground-state (1(10)-1(11)) rotational transition of ortho-H2D+ was observed with APEX towards the density peak of Oph D. The width of the H2D+ line indicates that the kinetic temperature in the core is about 6 K. So far, this is the most direct evidence of such cold gas in molecular clouds. The observed H2D+ spectrum can be reproduced with a hydrostatic model with the temperature increasing from about 6 K in the centre to almost 10 K at the surface. The model is unstable against any increase in the external pressure, and the core is likely to form a low-mass star. The results suggest that an equilibrium configuration is a feasible intermediate stage of star formation even if the larger scale structure of the cloud is thought to be determined by turbulent fragmentation. In comparison with the isothermal case, the inward decrease in the temperature makes smaller, i.e. less massive, cores susceptible to externally triggered collapse.
The decay B0 -> D K*0 and the charge conjugate mode are studied using 1.0fb-1 of pp collision data collected by the LHCb experiment at sqrt(s) = 7TeV in 2011. The CP asymmetry between the B0 -> D K*0 and the B0bar -> D K*0bar decay rates, with the ne
Using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) the COS Science Team has conducted a high signal-to-noise survey of 14 bright QSOs. In a previous paper (Savage et al. 2014) these far-UV spectra were used to discover 14
LMC2 has the highest X-ray surface brightness of all know supergiant shells in the Large Magellanic Cloud (LMC). The X-ray emission peaks within the ionized filaments that define the shell boundary, but also extends beyond the southern border of LMC2
We use the LDA+U method to study the possibility of exciton condensation in perovskites of transition metals with $d^6$ electronic configuration such as LaCoO$_3$. For realistic interaction parameters we find several distinct solutions exhibiting spi
The branching fractions of the doubly Cabibbo-suppressed decays $D^+rightarrow K^-K^+K^+$, $D^+rightarrow pi^-pi^+K^+$ and $D^+_srightarrowpi^-K^+K^+$ are measured using the decays $D^+rightarrow K^-pi^+pi^+$ and $D^+_srightarrow K^-K^+pi^+$ as norma