Determinations of S III, O IV, and NE V abundances in planetary nebulae from infrared lines

Shure, M. A.; Herter, T.; Houck, J. R.; Briotta, D. A.; Forrest, W. J.; Gull, G. E.; McCarthy, John F.

doi:10.1086/161155

Cited by 12 publications

(7 citation statements)

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“…Ground‐based observations have detected broad emission features attributed to silicates (mineral dust rich in silicon and oxygen), PAHs (polyaromatic hydrocarbons) and silicon carbide (SiC, at 11.5 μm), and a number of forbidden lines including [Ar iii ], [S iv ] and [Ne ii ]. Airborne observations with the Kuiper Airborne Observatory (McCarthy, Forrest & Houck 1978; Rubin et al 1997) and space‐based observations with IRAS (Pottasch et al 1986; Zhang & Kwok 1990, hereafter ZK) and ISO (Waters et al 1998; Beintema & Pottasch 1999) have extended the wavelength coverage to include the far‐infrared and portions of the mid‐infrared which are opaque to ground‐based observations, finding additional silicate features, PAH features and nebular forbidden lines, including [Ne v ] 14.3 μm, [Ne iii ] 15.56 μm and [S iii ] 18.71 μm in the MIR (Shure et al 1983). The particular value of these observations has been the examination of the broad dust (silicate, SiC, PAH) features which do not appear in the optical.…”

Section: Introductionmentioning

confidence: 99%

Mid-infrared spectroscopy of protoplanetary and planetary nebulae

Rinehart¹,

Houck²,

Smith³

et al. 2002

Monthly Notices of the Royal Astronomical Society

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Section: Introductionmentioning

confidence: 99%

Mid-infrared spectroscopy of protoplanetary and planetary nebulae

Rinehart¹,

Houck²,

Smith³

et al. 2002

Monthly Notices of the Royal Astronomical Society

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“…More recently Rowlands et al (1993) have detected [Ne V] j3425 in PNs with a tilting-Ðlter, nonimaging spectrometer, with subtraction of Balmer continuum and [O III] j3429. Shure et al (1983) and Rowlands et al (1989) have obtained spectra at the 24.28 km Ðne-structure transition of Ne V in PNs from the Kuiper Airborne Observatory. A key advantage of observing in the [Ne V] j3425 line is that this wavelength is detectable with blue-optimized, backside-illuminated charge-coupled devices (CCDs) on ground-based telescopes of moderate aperture with standard reÑective coatings (aluminum) and ultraviolet (UV) transmissive refractive elements (fused silica or calcium Ñuoride).…”

Section: Introductionmentioning

confidence: 99%

[Nev] Imaging of the Cygnus Loop

Szentgyorgyi

Raymond

Hester

et al. 2000

ApJ

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We present continuum-subtracted images of a 20@ ] 20@ region of the eastern Cygnus Loop (NGC 6995) in the 3425 forbidden line of Ne V. The images reveal bright linear Ðlaments which are associ-A ated with, but not positionally coincident with, bright features seen in Ha, [O III], and other narrowband images. In some areas, the [Ne V] Ðlaments deÐne the edge of X-rayÈemitting regions. The Ðlaments exhibit a peak surface brightness of 1.2 ] 10~4 photons cm~2 s~1 arcsec~2 at the top of the atmosphere in images with typical detection limits of D10~5 photons cm~2 s~1 arcsec~2. We present arguments that these structures are produced by radiative shock waves and discuss implications for the shock velocities and the three-dimensional structure of this section of the Cygnus Loop. We place limits on the importance of thermal conductionÈdriven evaporation as a contribution to the mass of X-rayÈemitting gas. Lack of evidence of [Ne V] emission resulting from thermal evaporation may have signiÐcance for supernova remnants and interstellar medium models that rely heavily on the importance of thermal evaporation. 5 ] 104 K) and the high-temperature regime imaged in X-rays (T º 106 K). The ionization potential of Ne IV is 97.11 eV, so the concentration of Ne V peaks at a temperature of D3 ] 105 K in collisionally ionized equilibrium plasmas. While there are alternative plasma diagnostics in this temperature regime (e.g., O VI, N V), only the forbidden Ne V lines at jj3345.8, 3425.9, corresponding to the 2p2 3PÈ2p2 1D transition, are observable at ground-based optical telescopes ; all other bright emission features formed near this temperature are well shortward of the atmospheric cuto † near 3000 or in the thermal infrared and thus are A the exclusive province of exoatmospheric telescopes. The j3425.9 feature (henceforth integerized to j3425) is preferred for narrowband imaging, since the transition probability is 2.7 times that of j3345.8 transition (Giles 1979 ;Nussbaumer & Rusca 1979 Rowlands et al. (1989) have obtained spectra at the 24.28 km Ðne-structure transition of Ne V in PNs from the Kuiper Airborne Observatory. A key advantage of observing in the [Ne V] j3425 line is that this wavelength is detectable with blue-optimized, backside-illuminated charge-coupled devices (CCDs) on ground-based telescopes of moderate aperture with standard reÑective coatings (aluminum) and ultraviolet (UV) transmissive refractive elements (fused silica or calcium Ñuoride). The images we present in this paper are the Ðrst continuum-subtracted astronomical images in [Ne V] j3425.While photoionized plasmas are characterized by highionization states and low temperatures, collisionally ionized plasma, as exempliÐed by SNR shocks, may have quite high temperatures. The requisite temperatures for strong Ne V concentrations occur behind shock with velocities 190È250 km s~1. For faster shocks, [Ne V] images "" connect ÏÏ hightemperature X-ray images to images of cooler plasmas in the postshock regions of the Ñow (Fig. 1). The morphology exhi...

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“…Only four lines have been measured earlier and the comparison is made difficult because different diaphragms were used. The IRAS measurements refer to the entire nebula, and this is probably the case for the measurements of Shure et al (1983). Increasing the ISO measurements by the factor 1.5 gives good agreement on average for the 3 lines above 12 µm and 1.72 appears consistent for the [S iv] line.…”

Section: Comparison With Other Infrared Observationsmentioning

confidence: 95%

“…But because the differences are less than 10% we have chosen not to use this more complicated variant. (1) Pottasch et al (1986); (2) re-reduced measurements; (3) Gillett et al 11 diaphragm; (4) Beck et al (1981) 6 diaphragm: (5) Shure et al (1983) 30 diaphragm.…”

Section: Comparison With Other Infrared Observationsmentioning

confidence: 99%

Abundances of planetary nebulae NGC 7662 and NGC 6741

Pottasch¹,

Beintema²,

Salas³

et al. 2001

A&A

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Abstract. The ISO and IUE spectra of the elliptical nebulae NGC 7662 and NGC 6741 are presented. These spectra are combined with the spectra in the visual wavelength region to obtain a complete, extinction corrected, spectrum. The chemical composition of the nebulae is then calculated and compared to previous determinations. The abundances found are compared to determinations made in other nebulae using ISO data. A discussion is given to see if possible evolutionary effects can be found from the abundance differences. IntroductionIncluding the ISO SWS spectra of planetary nebulae with spectra of the nebula in other spectral regions allows an abundance determination which has several important advantages. These have been discussed in earlier papers (e.g. see Pottasch & Beintema (1999), Pottasch et al. (2000), or Bernard Salas et al. (2001. The most important advantage is that the infrared lines originate from very low energy levels and thus give an abundance which is not sensitive to the temperature in the nebula, nor to possible temperature fluctuations. Furthermore, when a line originating from a high-lying energy level in the same ion is observed, it is possible to determine an effective temperature at which the lines in that particular ion are formed. When the effective temperature for many ions can be determined, it is possible to make a plot of effective temperature against ionization potential, which can be used to determine the effective temperature for ions for which only lines originating from a high energy level are observed. Use of an effective electron temperature takes into account the fact that ions are formed in different regions of the nebula. At the same time possible temperature fluctuations are taken into account.Use of the ISO spectra have further advantages. One of them is that the number of observed ions used in the Send offprint requests to: S. R. Pottasch, e-mail: pottasch@astro.rug.nl Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, The Netherlands and the UK) and with the participation of ISAS and NASA.abundance analysis is approximately doubled, which removes the need for using large "Ionization Correction Factors", thus substantially lowering the uncertainty in the abundance. A further advantage is that the extinction in the infrared is almost negligible, eliminating the need to include large correction factors.In much of the previously published analysis of PN using ISO spectra the nebulae involved had a bipolar morphology. In this paper we discuss two nebulae classified as "elliptical": NGC 7662 and NGC 6741. Their abundances will be compared to the other nebulae in the final section. The spectrum of NGC 7662 ISO observationsThe ISO SWS observations were made with the SWS02 observing template which gives good spectral resolution for a limited number of lines. This was supplemented by an SWS01 observation. The intensity of the lines found in the spectrum is shown in Table 1. The uncertainty of ...

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Determinations of S III, O IV, and NE V abundances in planetary nebulae from infrared lines

Cited by 12 publications

References 0 publications

Mid-infrared spectroscopy of protoplanetary and planetary nebulae

Mid-infrared spectroscopy of protoplanetary and planetary nebulae

[Nev] Imaging of the Cygnus Loop

Abundances of planetary nebulae NGC 7662 and NGC 6741

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