2002/10/10 by M. Contini, Marcella Contini · 15 citations
Engineering · Physics and Astronomy · #Astronomy #Astrophysics #Calibration and Measurement Techniques #Emission spectrum #Engineering Applied Research #Line (geometry) #Optical Systems and Laser Technology #Physics #Spectral line #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2003.06153.x
published in Monthly Notices of the Royal Astronomical Society 339(1), 125-132 (Oxford University Press) · 9 pages, MN LaTeX style (including 3 Tables) + 6 PostScript figures. To appear in The Monthly Notices of the Royal Astronomical Society
arxiv created 2002/10/10 · openalex publication_date 2003/02/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The UV and optical spectra from the HST FOS and from the FAST spectrograph at the Whipple Observatory at different phases are analysed, leading to new results about the configuration of AG Peg. Consistent modelling by the code SUMA, which accounts for the coupled effect of photoionisation from the hot star and the shock, shows the important role of at least three nebulae: 1) the nebula between the stars, downstream of the shock created by collision of the winds, which propagates in reverse towards the WD, 2) the nebula downstream of the shock expanding in the outskirts of the giant atmosphere, and 3) the shock propagating outwards the binary system, that is not reached by the hot source radiation. The relative contribution of the three nebulae to the final spectra at different phases are calculated for all the lines. It is found that the contribution to the different lines changes with the viewing angle of the system. The relatively low preshock density and magnetic field adopted in the modelling of the expanding shocks reveal that they are merging with the ISM, thus explaining the slow decline of AG Peg.