4,856 research outputs found
Detection of C3O in the low-mass protostar Elias 18
We have performed new laboratory experiments which gave us the possibility to
obtain an estimate of the amount of carbon chain oxides (namely C3O2, C2O, and
C3O) formed after irradiation (with 200 keV protons) of pure CO ice, at 16 K.
The analysis of laboratory data indicates that in dense molecular clouds, when
high CO depletion occurs, an amount of carbon chain oxides as high as 2-3x10^-3
with respect to gas phase carbon monoxide can be formed after ion irradiation
of icy grain mantles. Then we have searched for gas phase C2O and C3O towards
ten low-mass young stellar objects. Among these we have detected the C3O line
at 38486.891 MHz towards the low-mass protostar Elias 18. On the basis of the
laboratory results we suggest that in dense molecular clouds gas phase carbon
chain oxides are formed in the solid phase after cosmic ion irradiation of
CO-rich icy mantles and released to the gas phase after desorption of icy
mantles. We expect that the Atacama Large Millimeter Array (ALMA), thanks to
its high sensitivity and resolution, will increase the number of carbon chain
oxides detected in dense molecular clouds.Comment: 19 Pages, 5 figures, Accepted to Ap
ASCA view on High-Redshift Radio-Quiet Quasars
We briefly discuss the latest ASCA results on the X-ray spectral properties
of high-redshift radio-quiet quasars.Comment: 4 pages, 1 figure, to appear in the Proceedings of the Conference
"X-ray Astronomy '999: Stellar Endpoints, AGNs, and the Diffuse X-ray
Background (September 6-10 - 1999
A deep look at the inner regions of the mini-BAL QSO PG 1126-041 with XMM-Newton
A long XMM-Newton observation of the mini-BAL QSO PG 1126-041 allowed us to
detect a highly ionized phase of X-ray absorbing gas outflowing at v~15000
km/s. Physical implications are briefly discussed.Comment: 2 pages, 2 figures. Proceedings of "X.ray Astronomy 2009", Bologna
09/7-11/2009, AIP Conference Series, Eds. A. Comastri, M. Cappi, L. Angelin
Numerical study of the scaling properties of SU(2) lattice gauge theory in Palumbo non-compact regularization
In the framework of a non-compact lattice regularization of nonabelian gauge
theories we look, in the SU(2) case, for the scaling window through the
analysis of the ratio of two masses of hadronic states. In the two-dimensional
parameter space of the theory we find the region where the ratio is constant,
and equal to the one in the Wilson regularization. In the scaling region we
calculate the lattice spacing, finding it at least 20% larger than in the
Wilson case; therefore the simulated physical volume is larger.Comment: 24 pages, 7 figure
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