Astronomy and Astrophysics – Astrophysics
Scientific paper
Jul 1997
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997ap%26ss.251..285y&link_type=abstract
Astrophysics and Space Science, Volume 251, Issue 1-2, pp. 285-288
Astronomy and Astrophysics
Astrophysics
Scientific paper
The combination of a time-dependent spherically symmetric hydrodynamic model of stellar atmosphere pulsation and a radiation transport code, which incorporates maser saturation theory, enabled us to synthesise maps and spectra of H2O maser emission from the circumstellar envelopes of long period variable stars. The synthetic maps and spectra compare favourably with observed 22, 321 and 325 GHz H2O maser emission. As is observed in H2O maser regions the peak emission occurs between 3 8 stellar radii from the star. The calculated H2O maser regions are in conditions of nH2 = 106 - 108 cm-3, assuming a fractional abundance of 10-4; kinetic temperatures of 550 3000 K; dust ensemble temperatures of 500 1200 K and an accelerating velocity field. The IR radiation field is explicitly included in the radiation transport model, incorporating the latest absorption efficiency data for silicates from Draine. We reproduce the features seen in high angular resolution MERLIN spectral line datacubes. This shows that a mass outflow model which extends the photosphere using pulsations and incorporates radiation pressure on silicate based dust particles can produce the observed data on small (10-mas) angular scales.
Humphreys E. M. L.
Richards Anita M. S.
Yates Jeremy A.
No associations
LandOfFree
Simulating H2O Maser Emission in the Mass Outflows from Evolved Stars 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 Simulating H2O Maser Emission in the Mass Outflows from Evolved Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Simulating H2O Maser Emission in the Mass Outflows from Evolved Stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1184706