883 research outputs found
Ultra-micro indentation characterisation of mouthguard materials
Abstract no. 109published_or_final_versio
Aligned Molecular Clouds towards SS433 and L=348.5 degrees; Possible Evidence for Galactic "Vapor Trail" Created by Relativistic Jet
We have carried out a detailed analysis of the NANTEN 12CO(J=1-0) dataset in
two large areas of ~25 square degrees towards SS433 (l~40 degree) and of ~18
square degrees towards l~348.5 degree, respectively. We have discovered two
groups of remarkably aligned molecular clouds at |b|~1--5 degree in the two
regions. In SS433, we have detected 10 clouds in total, which are well aligned
nearly along the axis of the X-ray jet emanating from SS433. These clouds have
similar line-of-sight velocities of 42--56 km s^-1 and the total projected
length of the feature is ~300 pc, three times larger than that of the X-ray
jet, at a distance of 3 kpc. Towards l~348.5 degree, we have detected four
clouds named as MJG348.5 at line-of-sight velocities of -80 -- -95 km s^-1 in
V_LSR, which also show alignment nearly perpendicular to the Galactic plane.
The total length of the feature is ~400 pc at a kinematic distance of 6 kpc. In
the both cases, the CO clouds are distributed at high galactic latitudes where
such clouds are very rare. In addition, their alignments and coincidence in
velocity should be even rarer, suggesting that they are physically associated.
We tested a few possibilities to explain these clouds, including protostellar
outflows, supershells, and interactions with energetic jets. Among them, a
favorable scenario is that the interaction between relativistic jet and the
interstellar medium induced the formation of molecular clouds over the last
~10^5-6 yrs. It is suggested that the timescale of the relativistic jet may be
considerably larger, in the order of 10^5-6 yrs, than previously thought in
SS433. The driving engine of the jet is obviously SS433 itself in SS433,
although the engine is not yet identified in MJG348.5 among possible several
candidates detected in the X-rays and TeV gamma rays.Comment: 29 pages, 10 figures, already published in PASJ, 2008,60, 71
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