THE ORIGIN AND EVOLUTION OF THE HALO PN BoBn 1: FROM A VIEWPOINT OF CHEMICAL ABUNDANCES BASED ON MULTIWAVELENGTH SPECTRA

Journal Article · Mon Nov 01 04:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/723/1/658· OSTI ID:21467147

Otsuka, Masaaki ^[1]; Tajitsu, Akito ^[2]; Hyung, Siek ^[3]; Izumiura, Hideyuki ^[4]

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1. Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)
2. Subaru Telescope, NAOJ, 650 North A'ohoku Place, Hilo, HI 96720 (United States)
3. School of Science Education (Astronomy), Chungbuk National University, 12 Gaeshin-dong Heungduk-gu, CheongJu, Chungbuk 361-763 (Korea, Republic of)
4. Okayama Astrophysical Observatory, NAOJ, 3037-5, Honjo, Kamogata-cho, Asakuchi-shi, Okayama, 719-0232 (Japan)

We have performed a comprehensive chemical abundance analysis of the extremely metal-poor ([Ar/H] < -2) halo planetary nebula (PN) BoBn 1 based on International Ultraviolet Explorer archive data, Subaru/High-Dispersion Spectrograph spectra, VLT/UVES archive data, and Spitzer/IRS spectra. We have detected over 600 lines in total and calculated ionic and elemental abundances of 13 elements using detected optical recombination lines (ORLs) and collisionally excited lines (CELs). The estimations of C, N, O, and Ne abundances from the ORLs and Kr, Xe, and Ba from the CELs are done the first for this nebula, empirically and theoretically. The C, N, O, and Ne abundances from ORLs are systematically larger than those from CELs. The abundance discrepancies apart from O could be explained by a temperature fluctuation model, and that of O might be by a hydrogen-deficient cold component model. We have detected five fluorine and several slow neutron capture elements (the s-process). The amounts of [F/H], [Kr/H], and [Xe/H] suggest that BoBn 1 is the most F-rich among F-detected PNe and is a heavy s-process element rich PN. We have confirmed dust in the nebula that is composed of amorphous carbon and polycyclic aromatic hydrocarbons with a total mass of 5.8 x 10{sup -6} M{sub sun}. The photoionization models built with non-LTE theoretical stellar atmospheres indicate that the progenitor was a 1-1.5 M{sub sun} star that would evolve into a white dwarf with an {approx}0.62 M{sub sun} core mass and {approx}0.09 M{sub sun} ionized nebula. We have measured a heliocentric radial velocity of +191.6 {+-}1.3 km s{sup -1} and expansion velocity 2V{sub exp} of 40.5 {+-} 3.3 km s{sup -1} from an average over 300 lines. The derived elemental abundances have been reviewed from the standpoint of theoretical nucleosynthesis models. It is likely that the elemental abundances except N could be explained either by a 1.5 M{sub sun} single star model or by a binary model composed of 0.75 M{sub sun} + 1.5 M{sub sun} stars. Careful examination implies that BoBn 1 has evolved from a 0.75 M{sub sun} + 1.5 M{sub sun} binary and experienced coalescence during the evolution to become a visible PN, similar to the other extremely metal-poor halo PN, K 648 in M 15.

• OSTI ID: 21467147
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 723; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
AROMATICS
ATMOSPHERES
BARYONS
DUSTS
DWARF STARS
ELEMENTARY PARTICLES
ELEMENTS
EVOLUTION
FERMIONS
FLUORINE
HADRONS
HALOGENS
HYDROCARBONS
IONIZATION
MATHEMATICAL MODELS
METALS
NEBULAE
NEUTRONS
NONMETALS
NUCLEONS
NUCLEOSYNTHESIS
ORGANIC COMPOUNDS
PHOTOIONIZATION
PLANETARY NEBULAE
POLYCYCLIC AROMATIC HYDROCARBONS
S PROCESS
SLOW NEUTRONS
SPECTRA
STAR EVOLUTION
STAR MODELS
STARS
STELLAR ATMOSPHERES
SYNTHESIS
WHITE DWARF STARS