Bibcode
Riera, A.; Phillips, J. P.; Mampaso, A.
Referencia bibliográfica
(IAU, European Regional Astronomy Meeting, 11th, La Laguna, Spain, July 3-8, 1989) Astrophysics and Space Science (ISSN 0004-640X), vol. 171, no. 1-2, Sept. 1990, p. 231-234.
Fecha de publicación:
9
1990
Número de citas
4
Número de citas referidas
4
Descripción
Intermediate-long-slit spectroscopy of the protoplanetary-nebula
candidate CRL 618, obtained using an IPCS on the 2.5-m telescope at the
Observatorio Roque de los Muchachos, are reported. The data are
presented in plots of forbidden N II (6548 + 6584 A) vs H-alpha and
compared with the predictions of theoretical models. Best agreement is
found with the model of Canto (1978 and 1980), in which the outflow from
the central B star is supersonic with respect to the surrounding medium
and two shock waves develop, one propagating into the stellar wind and
one moving into the envelope of the primary. In this scenario the
expansion velocities of the molecular and ionized gas are 20 and 80
km/sec, respectively; the mass-loss rate is a few times 10 to the -6th
solar mass/yr; the velocity of the fast wind is about 140 km/sec; the
shocked-wind density is 100-1000/cu cm; the shocked-gas density in the
principal outflow envelope is 1,000-10,000/cu cm; and the shock velocity
within the envelope is about 50 km/sec.