Astronomy and Astrophysics – Astrophysics
Scientific paper
2000-07-27
Astronomy and Astrophysics
Astrophysics
31 Pages, Accepted in the Astrophysical Journal
Scientific paper
10.1086/317127
Using the U.C. Berkeley Infrared Spatial Interferometer with an RF filterbank, the first interferometric observations of mid-infrared molecular absorption features of ammonia (NH_3) and silane (SiH_4) with very high spectral resolution (R ~ 100000) were made. Under the assumptions of spherical symmetry and uniform outflow, these new data permitted the molecular stratification around carbon star IRC+10216 and red supergiant VY CMa to be investigated. For IRC+10216, both ammonia and silane were found to form in the dusty outflow significantly beyond both the dust formation and gas acceleration zones. Specifically, ammonia was found to form before silane in a region of decaying gas turbulence (>~ 20 R_star), while the silane is produced in a region of relatively smooth gas flow much further from the star (>~ 80 R_star). The depletion of gas-phase SiS onto grains soon after dust formation may fuel silane-producing reactions on the grain surfaces. For VY CMa, a combination of interferometric and spectral observations suggest that NH_3 is forming near the termination of the gas acceleration phase in a region of high gas turbulence (~ 40 R_star).
Danchi William C.
Hale David D. S.
Monnier John D.
Townes Charles H.
Tuthill Peter G.
No associations
LandOfFree
Mid-infrared interferometry on spectral lines: III. Ammonia and Silane around IRC+10216 and VY CMa does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Mid-infrared interferometry on spectral lines: III. Ammonia and Silane around IRC+10216 and VY CMa, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mid-infrared interferometry on spectral lines: III. Ammonia and Silane around IRC+10216 and VY CMa will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-719599