Issue |
A&A
Volume 478, Number 2, February I 2008
|
|
---|---|---|
Page(s) | 443 - 452 | |
Section | Interstellar and circumstellar matter | |
DOI | https://doi.org/10.1051/0004-6361:20078339 | |
Published online | 04 December 2007 |
VLA and Effelsberg observations of the interstellar medium around the runaway star WR 124
1
Instituto de Astronomía y Física del Espacio (IAFE), CC67, Suc.28, 1428 Buenos Aires, Argentina e-mail: scicho@iafe.uba.ar
2
Département de Physique and Observatoire du Mont Mégantic, Université Laval, Ste-Foy, Québec, G1K 7P4, Canada
3
Instituto Argentino de Radioastronomía, C.C.5, 1894 Villa Elisa, Argentina
4
Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, 1900 La Plata, Argentina
Received:
23
July
2007
Accepted:
22
October
2007
Aims.We present very large array (VLA) and Effelsberg radio
continuum and 21 cm line observations of the interstellar
medium (ISM) surrounding the runaway star WR 124 and the nebula
M 1-67. The H I data have been used to investigate the effects that
a star with a strong stellar wind and a high peculiar velocity has
on the ISM.
Methods.The VLA 21 cm H I observations were
combined with single-dish Effelsberg observations to produce a series
of H I images sensitive to all angular scales from the VLA resolution
limit (∼) up to the primary field of individual VLA
antennae (FWHM = 36′). MSX and IRIS images were used to analyze the
infrared emission around the star. Because the star is highly
supersonic with respect to its local ISM, the observed
H I distribution around the star is interpreted in terms of a simple
bow shock model.
Results.The analysis of the H I data reveals the presence
of a cavity centered on the star at an LSR velocity of ∼60 ,
consistent with a distance estimate of 5 kpc for WR 124. A second
H I cavity is observed located 10′ to the north of the stellar
position, consistent with the direction of motion of WR 124. The VLA
continuum image at 8.5 GHz shows a remarkable resemblance to the
optical images. All available radio continuum data suggest a purely
thermal spectrum for the nebula. The MSX and IRIS infrared data show
a changing morphology with wavelength. The dust temperature deduced
from the infrared luminosities is in agreement with previous
observations of bow shocks.
Key words: ISM: bubbles / ISM: individual objects: WR 124 / stars: Wolf-Rayet / ISM: H II regions
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.