Contents of: VI/111/./abstract/JCERNICH_CRL_SPEC.abs

The following document lists the file abstract/JCERNICH_CRL_SPEC.abs from catalogue VI/111.
A plain copy of the file (without headers/trailers) may be downloaded.

==> In this proposal, more observing time is requested for IRC_SPEC AND NERI_1
CRL618  is  the  brightest  C-rich  PPN  star.  It  has  a very rich chemistry
characterized  by  the  large  variety  of  molecular  species  formed  in the
different  regions  of its circumstellar envelope and in the innermost shocked
regions  of  its  CSE.    We propose to perform a full spectral survey of this
object  between  2.38  and 196.7 um using the SWS and LWS instruments. The SWS
full  resolution  grating  sweep  between  2.38  and  45  um  will allow us to
determine  the  molecular  content  of  all  molecular  species  through their
stretching  or bending vibrational bands. The SWS grating mode and Fabry-Perot
observations  will  probe the high velocity gas in this object which is in the
evolutionary  track  from  the  late-AGB  to  the young PN stage. The proposed
observations  are  expected  to  shed  light  on  the  chemical abundances and
excitation  conditions  in  the high velocity winds (HVWs) and will provide us
with  new  information  that will permit us to refine current knowledge on the
evolutionary appearance of HVWs.
Finally,  we would like to perform a fast LWS FP scan of CRL618 between 43 and
196.7  um.  The  signal  to  noise ratio will be large enough to detect strong
absorption  or  emission  lines  of  heavy  molecules or fine structure atomic
lines. Key molecules like C3, C4, C5, C6, C4H, C5H, C6H, C4H2, C6H2, ..., have
their  low-lying  bending  levels in the LWS frequency coverage. This spectral
scan  will permit to identify these species, study their role in the growth of
carbon  chains  and  to  characterize  their  spectral  constants. In order to
fully  characterize  this  object  we  would like to perfom an ISOCAM-CVF from
5  to  18  um.  The  dust emission, together with the molecular emission, will
allow a detailed study of this remarkable object.
After  IRC+10216,  CRL618 has the richest molecular spectrum at millimeter and
submillimeter  wavelenghts.  Taking into account that IRC+10216 is not visible
at  all  the  proposed  observations  will  constitute  the only high spectral
resolution survey performed by ISO in an evolved object.

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