The Formation of Crystalline Dust in AGB Winds from Binary-induced Spiral Shocks

Edgar, Richard G.; Nordhaus, Jason; Blackman, Eric G.; Frank, Adam

doi:10.1086/533436

Cited by 44 publications

(54 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the case of circumstellar disks, it is possible that the grains reside in the inner part of the disk close to the central star where the temperature is warm enough for annealing. It is also possible to anneal amorphous grains in-situ in colder parts of the disk by shocks or other processes (Desch & Cuzzi 2000;Ábrahám et al 2009;Edgar et al 2008). The composition of crystalline olivine formed by these processes is difficult to predict, since it is unlikely that the in-situ formation of crystals happens under equilibrium conditions.…”

Section: Formation Of Forsteritementioning

confidence: 99%

“…Heating of the dust above the glass temperature could also be caused by shocks in the circumstellar environment. It is unclear how such a process could play a role in the outflow of single stars, but shocks caused by binary interaction could create the conditions for heating up the amorphous grains sufficiently (Edgar et al 2008) either in the outflowing material or in a circumbinary disk. In the case of disks, it would also be possible that the grains reside in the inner part of the disk close to the central star where the temperature is high enough for annealing (Gail 2001;De Ruyter 2005).…”

Section: Introductionmentioning

confidence: 99%

“…Crystalline silicates are, however, also known to exist in disks that are too cold for annealing (Molster et al 1999a). This suggests that it should also be possible to anneal amorphous grains in-situ in colder parts of the disk by shocks or other processes (Desch & Cuzzi 2000;Ábrahám et al 2009;Edgar et al 2008).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Herschel/PACS observations of the 69μm band of crystalline olivine around evolved stars

Blommaert

Vries

Waters

et al. 2014

A&A

View full text Add to dashboard Cite

Context. We present 48 Herschel/PACS spectra of evolved stars in the wavelength range of 67-72 µm. This wavelength range covers the 69 µm band of crystalline olivine (Mg 2−2x Fe (2x) SiO 4 ). The width and wavelength position of this band are sensitive to the temperature and composition of the crystalline olivine. Our sample covers a wide range of objects: from high mass-loss rate AGB stars (OH/IR stars, Ṁ ≥ 10 −5 M /yr), through post-AGB stars with and without circumbinary disks, to planetary nebulae and even a few massive evolved stars. Aims. The goal of this study is to exploit the spectral properties of the 69 µm band to determine the composition and temperature of the crystalline olivine. Since the objects cover a range of evolutionary phases, we study the physical and chemical properties in this range of physical environments. Methods. We fit the 69 µm band and use its width and position to probe the composition and temperature of the crystalline olivine. Results. For 27 sources in the sample, we detected the 69 µm band of crystalline olivine (Mg (2−2x) Fe (2x) SiO 4 ). The 69 µm band shows that all the sources produce pure forsterite grains containing no iron in their lattice structure. The temperature of the crystalline olivine as indicated by the 69 µm band, shows that on average the temperature of the crystalline olivine is highest in the group of OH/IR stars and the post-AGB stars with confirmed Keplerian disks. The temperature is lower for the other post-AGB stars and lowest for the planetary nebulae. A couple of the detected 69 µm bands are broader than those of pure magnesium-rich crystalline olivine, which we show can be due to a temperature gradient in the circumstellar environment of these stars. The disk sources in our sample with crystalline olivine are very diverse. They show either no 69 µm band, a moderately strong band, or a very strong band, together with a temperature for the crystalline olivine in their disk that is either very warm (∼600 K), moderately warm (∼200 K), or cold (∼120 K), respectively.

show abstract

Section: Formation Of Forsteritementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Herschel/PACS observations of the 69μm band of crystalline olivine around evolved stars

Blommaert

Vries

Waters

et al. 2014

A&A

View full text Add to dashboard Cite

show abstract

“…Much more work is required to develop the scenario further, e.g. incorporating the role of spiral shocks in the spatial distribution of LIS (Sandquist et al 1998;Edgar et al 2008). …”

Section: A Binary Formation Scenario For Low-ionisation Structuresmentioning

confidence: 99%

Binary planetary nebulae nuclei towards the Galactic bulge

Miszalski

Acker

Parker

et al. 2009

A&A

144

218

View full text Add to dashboard Cite

Considerable effort has been applied towards understanding the precise shaping mechanisms responsible for the diverse range of morphologies exhibited by planetary nebulae (PNe). A binary companion is increasingly gaining support as a dominant shaping mechanism, however morphological studies of the few PNe that we know for certain were shaped by binary evolution are scarce or biased. Newly discovered binary central stars (CSPN) from the OGLE-III photometric variability survey have significantly increased the sample of post common-envelope (CE) nebulae available for morphological analysis. We present Gemini South narrow-band images for most of the new sample to complement existing data in a qualitative morphological study of 30 post-CE nebulae. Nearly 30% of nebulae have canonical bipolar morphologies, however this rises to 60% once inclination effects are incorporated with the aid of geometric models. This is the strongest observational evidence yet linking CE evolution to bipolar morphologies. A higher than average proportion of the sample shows low-ionisation knots, filaments or jets suggestive of a binary origin. These features are also common around emission-line nuclei which may be explained by speculative binary formation scenarios for H-deficient CSPN.

show abstract

“…Even if the right conditions do not arise and the accretion rate onto the companion is modest, simulations show that the focussing of the AGB wind by the companion should still cause a departure from spherical symmetry (e.g. Edgar et al 2008). The results of these simulations would seem to indicate that wide binaries can also have a significant influence on the morphology of any resulting PN, but there are so few PNe known to harbour wide binaries that it is particularly difficult to characterise their influence observationally.…”

Section: Introductionmentioning

confidence: 99%

The long-period binary central stars of the planetary nebulae NGC 1514 and LoTr 5

Jones

Winckel

Aller

et al. 2017

A&A

View full text Add to dashboard Cite

The importance of long-period binaries for the formation and evolution of planetary nebulae is still rather poorly understood, which in part is due to the lack of central star systems that are known to comprise such long-period binaries. Here, we report on the latest results from the on-going Mercator-HERMES survey for variability in the central stars of planetary nebulae. We present a study of the central stars of NGC 1514, BD+30• 623, the spectrum of which shows features associated with a hot nebular progenitor as well as a possible A-type companion. Cross-correlation of high-resolution HERMES spectra against synthetic spectra shows the system to be a highly eccentric (e ∼ 0.5) double-lined binary with a period of ∼3300 days. Previous studies indicated that the cool component might be a horizontal branch star of mass ∼0.55 M , but the observed radial velocity amplitudes rule out such a low mass. If we assume that the nebular symmetry axis and binary orbital plane are perpendicular, then the data are more consistent with a post-main-sequence star ascending towards the giant branch. We also present the continued monitoring of the central star of LoTr 5, HD 112313, which has now completed one full cycle, allowing the orbital period (P∼2700 days) and eccentricity (e ∼ 0.3) to be derived. To date, the orbital periods of BD+30• 623 and HD 112313 are the longest to have been measured spectroscopically in the central stars of planetary nebulae. Furthermore, these systems, along with BD+33• 2642, comprise the only spectroscopic wide-binary central stars currently known.

show abstract

The Formation of Crystalline Dust in AGB Winds from Binary-induced Spiral Shocks

Cited by 44 publications

References 29 publications

Herschel/PACS observations of the 69μm band of crystalline olivine around evolved stars

Herschel/PACS observations of the 69μm band of crystalline olivine around evolved stars

Binary planetary nebulae nuclei towards the Galactic bulge

The long-period binary central stars of the planetary nebulae NGC 1514 and LoTr 5

Contact Info

Product

Resources

About