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

The following document lists the file abstract/JCERNICH_IRC_SPEC.abs from catalogue VI/111.
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  IRC+10216  is  the  nearest  and brightest C-rich star. It has a rich
chemistry  characterized  by  a variety of processes (thermoequilibrium
reactions,  radical-  radical  reactions,  ion-molecule  reactions  and
possibly  grain  surface    reactions) and a large variety of molecular
species.  It  is the only C-rich envelope where metal-bearing molecules
have  been  found (NaCl, AlF, AlCl, KCl, MgNC, NaCN) and where the long
carbon chain radicals have been detected (C5H, C6H).
  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 to search
for  the  presence  of  nearly all likely molecular species by covering
their  stretching  and/or bending vibrational bands. It will also allow
to  determine  their  abundances.  Many  new molecules will probably be
detected,  and  our  knowledge  of  the  envelope molecular composition
greatly  improved.  The  spectral  resolution  provided by the SWS full
resolution  grating  observations,  R 1500-2000, will permit to resolve
the  rotational structure of the molecular bands arising from molecules
with    rotational  constants  larger  than  0.15  cm-1  --  i.e.  from
practically    all   diatomic  and  triatomic  species  and  from  some
four-atomic molecular species.
 In  order  to derive the physical conditions of the gas, we would also
like  to  observe  some ro-vibrational lines of known molecular species
with  the  SWS FP instrument.  Finally, we would like to perform a fast
LWS  FP  scan of IRC+10216 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. The spectral scan
will  allow to identify these species, precise their spectral constants
and study their role in the growth of carbon chains molecules.

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