论文标题
行星星云NGC 7009：ii的[S II]光谱图像。主要轴
The [S II] Spectral Images of the Planetary Nebula NGC 7009: II. Major Axis
论文作者
论文摘要
我们在椭圆形的行星nebula ngc 7009沿主要（PA = 77 $^{\ circ} $）轴沿主要的位置 - 速度密度分布图（PA = 77 $^{\ circ} $），并带有凯克雇用[SII] 6716/6731 \ a，Doublet Spectral频谱图像。主壳的平均密度和NGC 7009的平均密度源自[SII] 6716/673 \ a，在视力线上集成的通量表明，密度范围为$ n _ {\ rm e} $ = $ 10^{3.4} $ 10^{3.4} $ to formanties to^{3.4} $ to 10 $^3.9 $^{3.9} $ $ cmm cm^3} $ cm^3} nens wer在视线沿线的径向速度下解决，显示了大约10 $^{2.8} $ -10 $^{4.7} $ $ $ $ CM^{ - 3} $的范围相当大的范围。主壳的主要轴的派生投影角度约为$ψ\ sim $ 18.3（$ \ pm $ 2）$^{\ circ} $。假设主壳是一个椭圆形的外壳，$ a \ simeq $ 16 $''$和$ b \ simeq 6''$，我们发现了膨胀速度，半径和四个节和热气泡的范围。在对称位置处的四个结与纬度扩展的相同轴$ ϕ \ sim \ sim \ pm 34.5（\ pm 0.6）^{\ circ} $：一对在大约35 $ kmms^{ - 1} $近距离扩展的$ 60 $ kmss $ kmss $ kmss upplancy of 35 $ kmms^{ - 1} $ a。 $ r \ sim 16'' $。在纬度范围内$ ϕ = $ 65-75 $^{\ circ} $，相对较大的结构的热气泡迅速扩展，速度为130-150 $ kms^{ - 1} $。在与主要结构形成不同的时期，四到三个喷发形成的四个结和热气泡点似乎是由两到三个爆发形成的。
We derived position-velocity density distribution diagrams along the major (PA = 77$^{\circ}$) axis of the elliptical planetary nebula NGC 7009 with the Keck HIRES [SII] 6716/6731 \A, doublet spectral images. The average densities of the main shell and knots of NGC 7009 derived from the [SII] 6716/673 \A, fluxes integrated over the line of sight indicate a density range of $N_{\rm e}$ = $10^{3.4}$ to 10$^{3.9}$ $cm^{-3}$, while the local densities from the volume fraction resolved in radial velocities along the line of sight show a considerably large range of about 10$^{2.8}$ -- 10$^{4.7}$ $cm^{-3}$. The derived projection angle of the major axis of the main shell is about $ψ\sim$18.3($\pm$2)$^{\circ}$. Assuming that the main shell is an ellipsoidal shell with $a \simeq$16$''$ and $b \simeq 6''$, we found the range of expansion velocity, radius, and latitude of four knots and a hot bubble. The four knots at the points in symmetrical positions are roughly aligned with the same axis of expansion of latitudes $ϕ\sim \pm 34.5(\pm 0.6)^{\circ}$: One pair expands at about 35 $kms^{-1}$ close to the main ellipsoidal shell, and the other expands rapidly at about 60 $kms^{-1}$ at a distance of $r \sim 16''$. In the latitude range $ϕ= $65 -- 75$^{\circ}$, the hot bubble of a relatively large structure expands rapidly with a velocity of 130 -- 150 $kms^{-1}$. Four knots and hot bubble points that expand faster than the main shell appear to have been formed by two to three eruptions at a different epoch than the primary structure formation.
