2,809 research outputs found
The catalogue of OB associations in IC 1613
We present a catalogue of OB associations in IC 1613. Using an automatic and
objective method (Battinelli's 1991 technique) 60 objects were found. The size
distribution reveals a significant peak at about 60 parsecs if a distance
modulus of 24.27 mag is assumed. Spatial distributions of the detected
associations and H II regions are strongly correlated.Comment: 5 pages, 3 figures, A&A accepte
Appalachian Farmers: Building Value from Values
This trio of authors has presented a microcosm of values-based shared business practices, involving local food production and distribution in a small, rural Appalachian region in the United States. They focus upon the collective activities of a group committed to advancing local business practices while eliminating unnecessary transportation costs, boosting the region’s economic infrastructure, and most importantly, bringing people together to share experiences and pass along knowledge designed to benefit their communities and generate a sustainable agricultural-based economy
The influence of massive stars in the interstellar medium of IC 1613: the supernova remnant S8 and the nebula S3 associated with a WO star
We present a detailed kinematical analysis of two selected nebulae in the
Local Group irregular galaxy IC 1613. The nebulae are: S8, the only known
supernova remnant in this galaxy, and S3, a Wolf-Rayet nebula associated with
the only WO star in this galaxy. For S8, we have obtained and analyzed its
radial velocity field, where we found complex profiles which can be fitted by
several velocity components. These profiles also show the presence of high
velocity, low density gas. From this, we have obtained the expansion velocity,
estimated the preshock density and calculated the basic kinematical parameters
of this SNR. We suggest that in S8 we are seing a SNR partially hidden by dust.
This suggestion comes from the fact that the SNR is located between two
superbubbles where a ridge of obscured material unveils the existence of dust.
Moreover, we show that this hypothesis prevails when energetic arguments are
taken into account. In the case of S3, this nebula shows bipolar structure. By
means of its kinematics, we have analyzed its two lobes, the ``waist'', as well
as its relation with the nearest superbubbles. For the first time we are able
to see closed the NW lobe, showing a clover leaf shape. This fact allows a
better quantitative knowledge of the nebula as a whole. Furthermore, we found
evidence of an expansion motion in the NW lobe. In the light of our results, we
can express that these nebulae are the product of very massive stellar
evolution. It is surprising the influence these stars still have in shaping
their surrounding gas, and on the energy liberation towards the interstellar
medium of this galaxy.Comment: Accepted for publication in the Astronomical Journal, July issue. 11
pages, 12 figures. High resolution figures can be found at
http://www.inaoep.mx/~mago/PAPERS/AJ
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