28,886 research outputs found
Tracing the magnetic field morphology of the Lupus I molecular cloud
Deep R-band CCD linear polarimetry collected for fields with lines-of-sight
toward the Lupus I molecular cloud is used to investigate the properties of the
magnetic field within this molecular cloud. The observed sample contains about
7000 stars, almost 2000 of them with polarization signal-to-noise ratio larger
than 5. These data cover almost the entire main molecular cloud and also sample
two diffuse infrared patches in the neighborhood of Lupus I. The large scale
pattern of the plane-of-sky projection of the magnetic field is perpendicular
to the main axis of Lupus I, but parallel to the two diffuse infrared patches.
A detailed analysis of our polarization data combined with the Herschel/SPIRE
350 um dust emission map shows that the principal filament of Lupus I is
constituted by three main clumps acted by magnetic fields having different
large-scale structure properties. These differences may be the reason for the
observed distribution of pre- and protostellar objects along the molecular
cloud and its apparent evolutive stage. On the other hand, assuming that the
magnetic field is composed by a large-scale and a turbulent components, we find
that the latter is rather similar in all three clumps. The estimated
plane-of-sky component of the large-scale magnetic field ranges from about 70
uG to 200 uG in these clumps. The intensity increases towards the Galactic
plane. The mass-to-magnetic flux ratio is much smaller than unity, implying
that Lupus I is magnetically supported on large scales.Comment: 10 pages, 9 figures. Accepted for publication in Ap
Explosion of smoothness for conjugacies between multimodal maps
Let and be smooth multimodal maps with no periodic attractors and no
neutral points. If a topological conjugacy between and is
at a point in the nearby expanding set of , then is a smooth
diffeomorphism in the basin of attraction of a renormalization interval of .
In particular, if and are unimodal maps and
is at a boundary of then is in .Comment: 22 page
An Exact Approach to Early/Tardy Scheduling with Release Dates
In this paper we consider the single machine earliness/tardiness scheduling problem with di?erent release dates and no unforced idle time. The problem is decomposed into a weighted earliness subproblem and a weighted tardiness subproblem. Lower bounding procedures are proposed for each of these subproblems, and the lower bound for the original problem is then simply the sum of the lower bounds for the two subproblems. The lower bounds and several versions of a branch-and-bound algorithm are then tested on a set of randomly generated problems, and instances with up to 30 jobs are solved to optimality. To the best of our knowledge, this is the first exact approach for the early/tardy scheduling problem with release dates and no unforced idle time.scheduling, early/tardy, release dates, lower bounds, branch-and-bound
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