IAR   05382
INSTITUTO ARGENTINO DE RADIOASTRONOMIA
Unidad Ejecutora - UE
artículos
Título:
Runaway massive stars as variable gamma-ray sources
Autor/es:
DEL VALLE, M. V.; ROMERO, G. E.
Revista:
ASTRONOMY AND ASTROPHYSICS
Editorial:
EDP SCIENCES S A
Referencias:
Lugar: Paris; Año: 2014 vol. 563
ISSN:
0004-6361
Resumen:
Context. Runaway stars are ejected from their formation sites well
within molecular cores in giant dark clouds. Eventually, these stars can
travel through the molecular clouds, which are highly inhomogeneous. The
powerful winds of massive runaway stars interact with the medium forming
bowshocks. Recent observations and theoretical modelling suggest that
these bowshocks emit non-thermal radiation. As the massive stars move
through the inhomogeneous ambient gas the physical properties of the
bowshocks are modified, producing changes in the non-thermal emission.
Aims: We aim to compute the non-thermal radiation produced in the
bowshocks of runaway massive stars when travelling through a molecular
cloud. Methods: We calculate the non-thermal emission and
absorption for two types of massive runaway stars, an O9I and an O4I, as
they move through a density gradient. Results: We present the
spectral energy distributions for the runaway stars modelled.
Additionally, we obtain light curves at different energy ranges. We find
significant variations in the emission over timescales of ~1 yr.
Conclusions: We conclude that bowshocks of massive runaway stars, under
some assumptions, might be variable gamma-ray sources, with variability
timescales that depend on the medium density profile. These objects
might constitute a population of galactic gamma-ray sources turning on
and off within years.