High- and low-resolution UV spectrograms of the symbiotic star Z Andromedae were made during 1978-79 with the International Ultraviolet Explorer (IUE) and coordinated with ground-based observations. The spectrograms extend from 1200 to 3341 A and show a rich emission line spectrum with a wide range of ionization energy, from O I, Mg I and II and Fe II to He II, N V, O V, and Mg V. From the analysis of the emission lines, an electron density of 2 x 10 to the 10th/cu cm is derived, along with an emitting volume of 1 x 10 to the 37th/cu cm and a maximum line-of-sight thickness of 6 x 10 to the 10th cm. It is argued that the high-ionization emission lines are formed in a region which is not nebular, but in a solar-type transition zone around the cool star.
Altamore, A., Baratta G., B., Cassatella, A., Friedjung, M., Giangrande, A., Ricciardi, O., et al. (1981). Ultraviolet and coordinated ground based observations of Z Andromedae. THE ASTROPHYSICAL JOURNAL, 245, 630-643 [10.1086/158839].
Ultraviolet and coordinated ground based observations of Z Andromedae
ALTAMORE, Aldo;
1981-01-01
Abstract
High- and low-resolution UV spectrograms of the symbiotic star Z Andromedae were made during 1978-79 with the International Ultraviolet Explorer (IUE) and coordinated with ground-based observations. The spectrograms extend from 1200 to 3341 A and show a rich emission line spectrum with a wide range of ionization energy, from O I, Mg I and II and Fe II to He II, N V, O V, and Mg V. From the analysis of the emission lines, an electron density of 2 x 10 to the 10th/cu cm is derived, along with an emitting volume of 1 x 10 to the 37th/cu cm and a maximum line-of-sight thickness of 6 x 10 to the 10th cm. It is argued that the high-ionization emission lines are formed in a region which is not nebular, but in a solar-type transition zone around the cool star.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
