Artículo de revista
High resolution CO observations towards the Bright Eastern Knot of the SNR Puppis A
Fecha
2008-03Registro en:
ASTRONOMY & ASTROPHYSICS, Volume: 480, Issue: 2, Pages: 439-443, 2008
0004-6361
Autor
Paron, S.
Dubner, G.
Reynoso, E.
Rubio López, Mónica
Institución
Resumen
Aims. This paper reports molecular observations towards the Bright Eastern Knot
(BEK) in the SNR Puppis A, a feature where radio and X-ray studies suggest that the
shock front is interacting with a dense molecular clump.
Methods. We performed high-resolution millimetric observations towards the BEK of
Puppis A using the SEST telescope in the 12CO J=1–0 and 2–1 lines (beams of 45′′ and
23′′ respectively). More extended, lower angular resolution 12CO J=1–0 observations
taken from NANTEN archival data were also analyzed to obtain a complete picture.
Results. In the velocity range near 16 km s−1, the Puppis A systemic velocity, our study
revealed two important properties: (i) no dense molecular gas is detected immediately
adjacent to the eastern border of the BEK and (ii) the molecular clump detected very
close to the radiocontinuum maximum is probably located in the foreground along the
line of sight and has not yet been reached by the SNR shock front. We propose two
possible scenarios to explain the absence of molecular emission eastwards of the BEK
border of Puppis A. Either the shock front has completely engulfed and destroyed a
molecular clump or the shock front is interacting with part of a larger cloud and we
do not detect CO emission immediately beyond it because the molecules have been
dissociated by photodissociation and by reactions with photoionized material due to
the radiative precursor.