Symbiotic or planetary nebulae? Miguel Santander-García Romano L. M. Corradi Antonio Mampaso Asymmetrical Planetary Nebulae IV, Los Cancajos, La Palma, June 21, 2007
“Symbiotic Miras can do it” (APN II) “Symbiotic Miras are wide binary systems with Porb ~ tens - hundreds years which strongly interact and produce large aespherical nebulae” Symbiotic nebulae are not planetary nebulae: • PPN/PN → A star ejecting its envelope and (later) ionizing it • Symbiotic nebula → A hot star ionizing another star’s (mostly a Mira) envelope
But some objects classified as PPN/PN show: • High density nebular cores with complex spectra similar to those of symbiotic Miras • Hα line profiles with broad wings similar to those of symbiotic Miras • NIR colors similar to those of symbiotic Miras
DENIS NIR dereddened diagram Schmeja & Kimeswenger 2001 A&A 377, L 18 + 9 PPN
How could we distinguish them? PPN/PN Symbiotic Mira NGC 6537 Morphology indistinguishable ! Ionised mass ~0. 1 -1 M⊙ (PN) ~0. 01 M⊙
Hen 2 -104: Ionised mass estimate • By assuming a distance of 800 pc (Schwarz 1989) and determining a density of ne = 300 -1000 cm-3 for the Outer and Inner Lobes, Corradi & Schwarz (1993) estimated an ionised mass of ~0. 02 M⊙ for the nebula
Hen 2 -104: Ionised mass estimate II Santander-García et al. (in preparation) DJets = 3. 5 ± 0. 7 kpc VLT+ARGUS [SII] 6716 Å + [SII] 6731 Å Ionised mass of the nebula. . . ~0. 2 -1. 7 M⊙ !!!
Looking for the Mira • in the NIR spectrum Hen 2147 NTT+SOFI NIR spectrum dominated by the Mira
Looking for the Mira • in the NIR spectrum • in the NIR photometric monitoring Hen 2147 Ppulsation = 373 days
Looking for the Mira Hen 2104 NTT+SOFI Quite strong dust continuum component, some features from the Mira
Looking for the Mira Hora et al. 1999 Ap. JS 124, 195 Strong dust continuum component, no evidence of a cool companion
Looking for the Mira Smith 2005 MNRAS 342, 383 Strong dust continuum component, no evidence of a cool companion
Photometric variability • Mz 3: 6 records, small variabilty • M 2 -9: 4 records, no variability
M 2 -9: The Light House
Summary and conclusions • The ionised mass of the nebula around Hen 2 -104 is much larger than previously estimated • So far we have found no evidence of a Mira in suspected symbiotics like Mz 3 or M 2 -9 • From the observational point of view, it is sometimes difficult to distinguish symbiotic from genuine PPN/PN
Thank you!
Скачать презентацию Symbiotic or planetary nebulae Miguel Santander-García Romano L
5a36f8a61de74574d1bc81fac8ec6340.ppt