A multispectral view of the periodic events in Eta Carinae

• Autores: Damineli, A.; Hillier, D. J.; Corcoran, Michael; Stahl, O.; Groh, J. H.; Arias, Julia I.; Teodoro, M.; Morrell, Nidia I.; Gamen, Roberto C.; Gonzalez, Jorge F.; Leister, N. V.; Levato, Orlando H.; Levenhagen, R. S.; Grosso, Monica G.; Albacete Colombo, Juan Facundo; Wallerstein, G.
• Año de publicación: 2008
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Ciencias Exactas y Naturales; stars; η Carinae; Ciencias Exactas y Naturales
• Institución: Universidad Nacional de Río Negro

Fil: Damineli, A. Universidade de Sao Paulo; Brasil
Fil: Hillier, D. J. University of Pittsburgh; Estados Unidos
Fil: Corcoran, Michael. CRESST and X-ray Astrophysics Laboratory; Estados Unidos
Fil: Stahl, O. Zentrum für Astronomie. Landessternwarte; Alemania
Fil: Groh, J. H. Universidade de Sao Paulo; Brasil
Fil: Arias, Julia I. Universidad de La Serena; Chile
Fil: Teodoro, M. Universidade de Sao Paulo; Brasil
Fil: Morrell, Nidia I. Las Campanas Observatory; Chile
Fil: Gamen, Roberto C. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; Argentina
Fil: Gonzalez, Jorge F. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico ; Argentina
Fil: Leister, N. V.. Universidade de Sao Paulo; Brasil
Fil: Levato, Orlando H. Consejo Nacional de Investigaciones Científicas y Técnicas. Argentina
Fil: Levenhagen, R. S.. Universidade de Sao Paulo; Brasil
Fil: Grosso, Monica G. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Albacete Colombo, Juan F. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina
Fil: Wallerstein, G.. University of Washington; Estados Unidos
A full description of the 5.5-yr low excitation events in η Carinae is presented. We show that they are not as simple and brief as previously thought, but a combination of two components. The first, the slow variation component, is revealed by slow changes in the ionization level of circumstellar matter across the whole cycle and is caused by gradual changes in the wind– wind collision shock-cone orientation, angular opening and gaseous content. The second, the collapse component, is restricted to around the minimum, and is due to a temporary global collapse of the wind–wind collision shock. High-energy photons (E > 16 eV) from the companion star are strongly shielded, leaving the Weigelt objects at low-ionization state for more than six months. High-energy phenomena are sensitive only to the collapse, low energy only to the slow variation and intermediate energies to both components. Simple eclipses and mechanisms effective only near periastron (e.g. shell ejection or accretion on to the secondary star) cannot account for the whole 5.5-yr cycle. We find anti-correlated changes in the intensity and the radial velocity of P Cygni absorption profiles in Fe II λ6455 and He I λ7065 lines, indicating that the former is associated to the primary and the latter to the secondary star. We present a set of light curves representative of the whole spectrum, useful for monitoring the next event (2009 January 11).