The gas turbulence in planetary nebulae: quantification and multi-D maps from long-slit, wide-spectral range echellograms

Sabbadin, F.; Turatto, M.; Benetti, S.; Ragazzoni, Roberto

doi:10.1051/0004-6361:200809429

Cited by 7 publications

(5 citation statements)

References 46 publications

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“…Lower values of turbulence produce a symmetric brightness, even in the optically thick regime. This is a reasonable value for turbulence velocity in PNe (Guerrero, Villaver, & Manchado 1998;Sabbadin et al 2008).…”

Section: 1)supporting

confidence: 58%

ALMA imaging of the nascent planetary nebula IRAS 15103–5754

Gómez

Niccolini

Suárez

et al. 2018

Monthly Notices of the Royal Astronomical Society

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We present continuum and molecular-line (CO, C18O, HCO+) observations carried out with the Atacama Large Millimeter/submillimeter Array toward the ‘water fountain’ star IRAS 15103–5754, an object that could be the youngest planetary nebula (PN) known. We detect two continuum sources, separated by 0.39 ± 0.03 arcsec. The emission from the brighter source seems to arise mainly from ionized gas, thus confirming the PN nature of the object. The molecular-line emission is dominated by a circumstellar torus with a diameter of ≃0.6 arcsec (2000 au) and expanding at ≃23 km s−1. We see at least two gas outflows. The highest-velocity outflow (deprojected velocities up to 250 km s−1), traced by the CO lines, shows a biconical morphology, whose axis is misaligned ≃14° with respect to the symmetry axis of the torus, and with a different central velocity (by ≃8 km s−1). An additional high-density outflow (traced by HCO+) is oriented nearly perpendicular to the torus. We speculate that IRAS 15103–5754 was a triple stellar system that went through a common envelope phase, and one of the components was ejected in this process. A subsequent low-collimation wind from the remaining binary stripped out gas from the torus, creating the conical outflow. The high velocity of the outflow suggests that the momentum transfer from the wind is extremely efficient, or that we are witnessing a very energetic mass-loss event.

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Section: 1)supporting

confidence: 58%

ALMA imaging of the nascent planetary nebula IRAS 15103–5754

Gómez

Niccolini

Suárez

et al. 2018

Monthly Notices of the Royal Astronomical Society

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“…Gesicki et al (2006) also estimated that only about 1/10 of PNe around H-rich central stars needed the assumption of a turbulent velocity component in order to explain their emission line profiles whereas the share for PNe around H-deficient central stars is rather 9/10. Note, however, that these numbers can only be considered approximate since ambiguities with assumptions of slightly altered non-turbulent velocity laws within the nebulae cannot be excluded (Sabbadin et al 2008). Thus, shares of 0 and 1 resp.…”

Section: Interpreting the Observationsmentioning

confidence: 99%

The evolution of planetary nebulae

Jacob

Schönberner

Steffen

2013

A&A

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Context. The visibility time of planetary nebulae (PNe) in stellar systems is an essential quantity for estimating the size of a PN population in the context of general population studies. For instance, it enters directly into the PN death rate determination. Aims. The basic ingredient for determining visibility times is the typical nebular expansion velocity, as a suited average over all PN sizes of a PN population within a certain volume or stellar system. The true expansion speed of the outer nebular edge of a PN is, however, not accessible by spectroscopy -a difficulty that we surmount by radiation-hydrodynamics modelling. Methods. We first discuss the definition of the PN radius and possible differences between the observable PN radius and its physical counterpart, the position of the leading shock of the nebular shell. We also compare the Hα surface-brightness evolution predicted by our radiation-hydrodynamics models with the recent Hα surface-brightness radius calibration of Frew (2008, Ph.D. Thesis, Macquarie University, Australia) and find excellent agreement. We then carefully investigate the existing spectroscopic data on nebular expansion velocities for a local PN sample with objects up to a distance of 2 kpc with well-defined round/elliptical shapes. We evaluate, by means of our radiation-hydrodynamics models, how these observed expansion velocities must be corrected in order to get the true expansion speed of the outer nebular edge. Results. We find a mean true expansion velocity of 42 km s −1 , i.e. nearly twice as high as the commonly adopted value to date. Accordingly, the time for a PN to expand to a radius of, say 0.9 pc, is only 21 000 ± 5000 years. This visibility time of a PN holds for all central star masses since a nebula does not become extinct as the central star fades. There is, however, a dependence on metallicity in the sense that the visibility time becomes shorter for lower nebular metal content. Conclusions. These statements on the visibility time only hold for volume-limited samples. Extragalactic samples that contain spatially unresolved nebulae are flux limited, and in this case the visibility time directly depends on the limiting magnitude of the survey. To reach a visibility time of 21 000 years, the survey must reach about 7 mag below the bright cut-off of the planetary nebula luminosity function. With the higher expansion rate of PNe derived here we determined their local death-rate density as (1.4 ± 0.5) × 10 −12 PN pc −3 yr −1 , using the local PN density advocated by .

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“…Turbulent velocities are contributing also to the FWHM. Such velocities have been analysed, among others, by Sabbadin et al (2008); ; . The latter authors concluded that turbulence is significant in PNe with [WC] central stars, but has small values in other PNe.…”

Section: The Kinematicsmentioning

confidence: 99%

Abundance Discrepancy Factors in high density planetary nebulae

Ruiz-Escobedo,

Peña

2022

Preprint

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From high-resolution spectra, chemical abundances from collisionally excited lines (CELs) and optical recombination lines (ORLs) have been determined for planetary nebulae Cn 3-1, Vy 2-2, Hu 2-1, Vy 1-2 and IC 4997, which are young and dense objects. The main aim of this work is to derive their O +2 /H + Abundance Discrepancy Factors, ADFs, between CELs and ORLs. He, O, N, Ne, Ar, S, and Cl abundances were obtained and our values are in agreement with those previously reported. We found that Cn 3-1, Hu 2-1, and Vy 1-2 have O abundances typical of disc PNe, while Vy 2-2 and IC 4997 are low O abundance objects (12 + log(O/H) ∼ 8.2), which can be attributed to possible O depletion into dust grains. ADFs(O +2 ) of 4.30 +1.00 −1.16 , 1.85 ± 1.05, 5.34 +1.27 −1.08 and 4.87 +4.34 −2.71 were determined for Vy 2-2, Hu 2-1, Vy 1-2 and IC 4997, respectively. The kinematics of CELs and ORLs was analysed for each case to study the possibility that different coexisting plasmas in the nebula emit them. Expansion velocities of [O ] and O are equal within uncertainties in three PNe, providing no evidence for these lines being emitted in different zones. Exception are Hu 2-1 and Vy 2-2, where ORLs might be emitted in different zones than CELs. For Vy 2-2 and IC 4997 we found that nebular and auroral lines of the same ion (S + , N + , Ar +2 , Ar +3 , O +2 ) might present different expansion velocities. Auroral lines show lower V exp which might indicate that they are emitted in a denser and inner zone than the nebular ones.

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The gas turbulence in planetary nebulae: quantification and multi-D maps from long-slit, wide-spectral range echellograms

Cited by 7 publications

References 46 publications

ALMA imaging of the nascent planetary nebula IRAS 15103–5754

ALMA imaging of the nascent planetary nebula IRAS 15103–5754

The evolution of planetary nebulae

Abundance Discrepancy Factors in high density planetary nebulae

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