The optical spectrum of the young planetary nebula Hubble 12

Hyung, Siek; Aller, L. H.

doi:10.1093/mnras/278.2.551

Cited by 46 publications

(48 citation statements)

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“…The southern lobe is clearly detected from −30 km s −1 to 30 km s −1 , whereas the northern lobe is detected from 30 km s −1 to 90 km s −1 , indicating an inclination of the main nebular axis from the innermost region of the nebula with respect to the plane of the sky, with the northern lobe tilted away from the observer and the southern one toward the observer. This tilt of the main bipolar axis in the inner nebular region coincides with the results inferred by Hyung & Aller (1996) and Vaytet et al (2009) from optical spectroscopy at larger scales. The [Fe ii] lobes coincide spatially with the shock-excited [Fe ii] "polar bubbles" described by (Welch et al 1999).…”

Section: Lobessupporting

confidence: 89%

“…It ranges from 2.24 kpc (Cahn et al 1992), 8.1 kpc (Zhang 1995), to the extreme value of 14.25 kpc (Stanghellini & Hayworth 2010). Hb 12 is a low excitation PN (Hyung & Aller 1996;Sahai & Trauger 1998;Rudy et al 1993) with its inner regions dominated by UV-excited, fluorescent, H 2 emission (Dinerstein et al 1988). Radiative fluorescence has been shown to dominate over shock excitation in the inner core regions of young PNe (Smith et al 2003) and to be correlated to the evolutionary stage of the post-asymptotic-giant-branch star, as this becomes hot enough to produce UV photons (García-Hernandez et al 2002).…”

Section: Resultsmentioning

confidence: 99%

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A DETAILED STUDY OF THE STRUCTURE OF THE NESTED PLANETARY NEBULA, Hb 12, THE MATRYOSHKA NEBULA

Clark¹,

López²,

Edwards

et al. 2014

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We present near-IR, integral field spectroscopic observations of the planetary nebula (PN) Hb 12 using Nearinfrared Integral Field Spectrograph (NIFS) on Gemini-North. Combining NIFS with the adaptive optics system Altair, we provide a detailed study of the core and inner structure of this PN. We focus the analysis in the prominent emission lines [Fe ii] (1.6436 μm), He i (2.0585 μm), H 2 (2.1214 μm), and Br γ (2.16553 μm). We find that the [Fe ii] emission traces a tilted system of bipolar lobes, with the northern lobe being redshifted and the southern lobe blueshifted. The [Fe ii] emission is very faint at the core and only present close to the systemic velocity. There is no H 2 emission in the core, whereas the core is prominent in the He i and Br γ recombination lines. The H 2 emission is concentrated in equatorial arcs of emission surrounding the core and expanding at ∼30 km s −1 . These arcs are compared with Hubble Space Telescope images and shown to represent nested loops belonging to the inner sections of a much larger bipolar structure that replicates the inner one. The He i and Br γ emission from the core clearly show a cylindrical central cavity that seems to represent the inner walls of an equatorial density enhancement or torus. The torus is 0. 2 wide (≡200 AU radius at a distance of 2000 pc) and expanding at 30 km s −1 . The eastern wall of the inner torus is consistently more intense than the western wall, which could indicate the presence of an off-center star, such as is observed in the similar hourglass PN, MyCn 18. A bipolar outflow is also detected in Br γ emerging within 0. 1 from the core at ∼±40 km s −1 .

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Section: Lobessupporting

confidence: 89%

Section: Resultsmentioning

confidence: 99%

A DETAILED STUDY OF THE STRUCTURE OF THE NESTED PLANETARY NEBULA, Hb 12, THE MATRYOSHKA NEBULA

Clark¹,

López²,

Edwards

et al. 2014

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“…A compilation of the relevant references for the transition probabilities and collision strengths used in this paper to derive T e, N e and the ionic and chemical composition is given by Hyung & Aller (1996) and Liu et al (2000).…”

Section: The Physical Conditionsmentioning

confidence: 99%

The 3-D ionization structure of the planetary nebula NGC 6565

Turatto

Ragazzoni

Benetti

et al. 2002

A&A

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Abstract.A detailed study of the planetary nebula NGC 6565 has been carried out on long-slit echellograms (λ/∆λ = 60 000, spectral range = λλ3900-7750Å) at six, equally spaced position angles. The expansion velocity field, the c(Hβ) distribution and the radial profile of the physical conditions (electron temperature and density) are obtained. The distance, radius, mass and filling factor of the nebula and the temperature and luminosity of the central star are derived. The radial ionization structure is analyzed using both the classical method and the photo-ionization code CLOUDY. Moreover, we present the spatial structure in a series of images from different directions, allowing the reader to "see" the nebula in 3-D. NGC 6565 results to be a young (2000-2500 years), patchy, optically thick triaxial ellipsoid (a = 10.1 arcsec, a/b = 1.4, a/c = 1.7) projected almost pole-on. The matter close to major axis was swept-up by some accelerating agent (fast wind? ionization? magnetic fields?), forming two faint and asymmetric polar cups. A large cocoon of almost neutral gas completely embeds the ionized nebula. NGC 6565 is in a recombination phase, because of the luminosity drop of the massive powering star, which is reaching the white dwarf domain (log T * 5.08 K; log L * /L 2.0). The stellar decline started about 1000 years ago, but the main nebula remained optically thin for other 600 years before the recombination phase occurred. In the near future the ionization front will re-grow, since the dilution factor due to the expansion will prevail on the slower and slower stellar decline. NGC 6565 is at a distance of 2.0 (±0.5) kpc and can be divided into three radial zones: the "fully ionized" one, extending up to 0.029-0.035 pc at the equator (0.050 pc at the poles), the "transition" one, up to 0.048-0.054 pc (0.080 pc), the "halo", detectable up to 0.110 pc. The ionized mass ( 0.03 M ) is only a fraction of the total mass (≥0.15 M ), which has been ejected by an equatorial enhanced superwind of 4 (±2) × 10 −5 M yr −1 lasted for 4 (±2) × 10 3 years.

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“…Thus, for instance, Bohigas (1994), Goodrich (1991), Trammell & Goodrich (1996) and Lopez et al (1995) have noted spectral signatures consistent with shocks extending throughout large fractions of the nebular ionised regimes, whilst Cuesta et al (1993Cuesta et al ( , 1995 have found that the spatio-kinematic structures of certain sources are consistent with shock interaction between interior winds and external (superwind) envelopes. These latter models (see also Balick et al 1987;Icke & Preston 1989;Icke et al 1992) also bear a striking resemblance to the radiative modelling structures of Hyung et al (1994 and Hyung & Aller (1996), and it is pertinent to ask whether such radiative analyses should not also make allowance for components of shock excitation.…”

Section: Shock Excitation Of the Nebular Spectramentioning

confidence: 99%

“…Aller 1982), lower excitation line simulations are frequently grossly in error (cf. Köppen 1983;Middlemass 1990); a disparity which has only partially been alleviated through recent use of more realistic (nonhomogeneous, non-spherically symmetric) source structures (Hyung et al 1994Hyung & Aller 1996). Whilst the reasons for these differences are far from clear, it appears likely that "excess" components of emission are associated (in part) with micro-filamentary structures and clumps (Hyung et al 1994Köppen 1979;Boeshaar 1974;.…”

Section: Introductionmentioning

confidence: 99%

Spectral trends in planetary nebulae: The roles of radiative and shock excitation

Phillips¹,

Guzmán²

1998

Astron. Astrophys. Suppl. Ser.

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Abstract. We have investigated de-reddened spectral line ratios for some 538 planetary nebulae. As a result, it has proved possible to define comparative variations between differing transitions, evaluate the viability of radiative modeling for the generality of nebulae, and assess the importance of shocks in modifying low-excitation line strengths. Whilst most transitions are well represented in terms of radiative excitation, the [OI] λ6300Å line appears to be appreciably too strong in most of the present sample; a deviation which may arise through shock interaction between the primary outflow shell and enveloping superwind material. Comparison between shock modeling and line excesses also suggests that an appreciable proportion of [SII] λ6716/31Å emission may arise through shock excitation; a conclusion which, if confirmed, may have serious consequences for nebular density estimations. Some 14 nebulae are identified as likely shock candidates, whilst it is proposed that the majority of bipolar nebulae may also show spectral deviations associated with shock excitation. Line excesses for these latter sources are most consistent with shock velocities V s ∼ 80 ⇒ 100 km s −1 ; values which are also comparable to observed wind velocities.Finally, sources containing FLIERs (Balick et al. 1993) are shown to be confined to highly specific spectral regimes; a result which permits us to identify three further possible FLIER sources, and propose characteristic line ratio diagnostics for the further discovery of such features.

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The optical spectrum of the young planetary nebula Hubble 12

Cited by 46 publications

References 0 publications

A DETAILED STUDY OF THE STRUCTURE OF THE NESTED PLANETARY NEBULA, Hb 12, THE MATRYOSHKA NEBULA

A DETAILED STUDY OF THE STRUCTURE OF THE NESTED PLANETARY NEBULA, Hb 12, THE MATRYOSHKA NEBULA

The 3-D ionization structure of the planetary nebula NGC 6565

Spectral trends in planetary nebulae: The roles of radiative and shock excitation

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