C. S. Peri, P. Benaglia, D. P. Brookes, I. R. Stevens, N. Isequilla
Context: Bow shocks are produced by many astrophysical objects where shock
waves are present. Stellar bow shocks, generated by runaway stars, have been
previously detected in small numbers and well-studied. Along with progress in
model development and improvements in observing instruments, our knowledge of
the emission produced by these objects and its origin can now be more clearly
understood. Aims: We produce a stellar bow-shock catalogue by applying uniform
search criteria and a systematic search process. This catalogue is a starting
point for statistical studies, to help us address fundamental questions such
as, for instance, the conditions under wich a stellar bow shock is detectable.
Methods: By using the newest infrared data releases, we carried out a search
for bow shocks produced by early-type runaway stars. We first explored whether
a set of known IRAS bow shock candidates are visible in the most recently
available IR data, which has much higher resolution and sensitivity. We then
carried out a selection of runaway stars from the latest, large runaway
catalogue available. In this first release, we focused on OB stars and searched
for bow-shaped features in the vicinity of these stars. Results: We provide a
bow-shock candidate survey that gathers a total of 28 members which we call the
Extensive stellar BOw Shock Survey (E-BOSS). We derive the main bow-shock
parameters, and present some preliminary statistical results on the detected
objects. Conclusions: Our analysis of the initial sample and the newly detected
objects yields a bow-shock detectability around OB stars of $\sim$ 10 per cent.
The detections do not seem to depend particularly on either stellar mass, age
or position. The extension of the E-BOSS sample, with upcoming IR data, and by
considering, for example, other spectral types as well, will allow us to
perform a more detailed study of the findings.
View original:
http://arxiv.org/abs/1109.3689
No comments:
Post a Comment