2 Observations

Moderate resolution, integral field observations were obtained on 2010 April 22 under program number 1100147 (PI: Q.A. Parker) with the Wide Field Spectrograph (WiFeS; Dopita et al., 2007; Dopita et al., 2010) mounted on the Australian National University (ANU) 2.3 m telescope at Siding Spring Observatory. CCD chips with $4096 \times 4096$ pixels are used as detectors. The spectrograph samples 0$\mbox{$.\!\!^{\prime\prime}$}$$5$ along each of twenty five $38\hbox{$^{\prime\prime}$}\times 1\hbox{$^{\prime\prime}$}$ slitlets, which provides a field-of-view of $25\hbox {$^{\prime \prime }$}\times 38\hbox {$^{\prime \prime }$}$ and a spatial resolution element of $1$$\mbox{$.\!\!^{\prime\prime}$}$$0\times0$$\mbox{$.\!\!^{\prime\prime}$}$$5$. Each slitlet is designed to project to 2 pixels on the CCD chips, yielding a reconstructed point-spread function with a full width at half maximum (FWHM) of $\sim 2\hbox{$^{\prime\prime}$}$.

Figure 1 shows the WiFeS areal footprint used for our study. The main shell, the northeast (NE) jet and the southwest (SW) jet are also labeled on the figure. We used the spectral resolution of $R\sim 7000$, covering $\lambda\lambda$4415-5589Å in the blue channel and $\lambda\lambda$5222-7070Å in the red channel. The red spectrum has a linear wavelength dispersion per pixel of $0.45$ Å, which yields a resolution of $\sim 20$ kms${}^{-1}$ in velocity channels. The exposure time of 20min used for our observation yields a signal-to-noise ratio of S/N $\gtrsim 10$ for the [NII] emission line. Data reduction was performed with the wifes IRAF package (described by Danehkar et al., 2014; Danehkar et al., 2013).

Figure: From left to right, spatial distribution maps of flux intensity and LSR velocity of [NII] $\lambda$6584. Flux unit is in logarithm of $10^{-15}$ ergs${}^{-1}$cm${}^{-2}$spaxel${}^{-1}$ and velocity in kms${}^{-1}$. The rectangles show apertures used to extract fluxes across the main shell ( $6\hbox {$^{\prime \prime }$}\times 7\hbox {$^{\prime \prime }$}$), and the NE and SW jets ( $4\hbox {$^{\prime \prime }$}\times 7\hbox {$^{\prime \prime }$}$). The white/black contour lines show the distribution of the narrow-band emission of H$\alpha$ in arbitrary unit obtained from the SHS. North is up and east is toward the left-hand side.

Table: Observed line fluxes $F(\lambda )$ and dereddened fluxes $I(\lambda )$ measured from the apertures shown in Fig.2.

$\lambda_{0}$(Å)	ID	Mult	Main Shell		NE Jet		SW Jet
			$F(\lambda )$	$I(\lambda )$	$F(\lambda )$	$I(\lambda )$	$F(\lambda )$	$I(\lambda )$
4471.50	HeI	V14	4.56	5.67	4.07	4.97	3.75	4.58
4609.44	OII	V92a	0.03	0.04	-	-	-	-
4634.14	NIII	V2	0.13	0.15	-	-	-	-
4649.13	OII	V1	0.35	0.39	-	-	-	-
4676.23	OII	V1	0.09	0.10	-	-	-	-
4685.68	HeII	3.4	0.30	0.34	0.34	0.37	-	-
4740.17	[ArIV]	F1	0.51	0.54	-	-	-	-
4861.33	HI4-2	H4	100.00	100.00	100.00	100.00	100.00	100.00
4881.11	[FeIII]	F2	0.05	0.05	-	-	-	-
4921.93	HeI	V48	1.45	1.41	-	-	1.68	1.63
4958.91	[OIII]	F1	226.94	214.89	172.83	164.37	193.45	184.01
5006.84	[OIII]	F1	728.99	672.08	529.92	491.74	589.62	547.27
5666.63	NII	V3	0.07	0.04	-	-	-	-
5679.56	NII	V3	0.11	0.07	-	-	-	-
5754.60	[NII]	F3	1.03	0.66	2.21	1.47	1.35	0.90
5875.66	HeI	V11	24.78	15.20	23.82	15.20	25.96	16.58
6101.83	[KIV]	F1	0.05	0.03	-	-	-	-
6312.10	[SIII]	F3	2.24	1.18	-	-	-	-
6461.95	CII	V17.04	0.12	0.06	-	-	-	-
6548.10	[NII]	F1	26.55	12.87	82.73	42.49	56.74	29.21
6562.77	HI3-2	H3	-	286.00	564.29	288.58	564.65	289.38
6583.50	[NII]	F1	81.59	39.10	258.01	131.14	174.03	88.64
6678.16	HeI	V46	8.60	4.00	8.59	4.25	8.81	4.36
6716.44	[SII]	F2	8.16	3.75	39.09	19.11	28.82	14.12
6730.82	[SII]	F2	12.97	5.93	36.51	17.78	30.02	14.65
$c$(H$\beta$)				0.989		0.910		0.907

Table 1 presents a full list of observed line fluxes measured from three different apertures shown in Fig.2: the main shell ( $6\hbox {$^{\prime \prime }$}\times 7\hbox {$^{\prime \prime }$}$), the NE jet ( $4\hbox {$^{\prime \prime }$}\times 7\hbox {$^{\prime \prime }$}$) and the SW jet ( $4\hbox {$^{\prime \prime }$}\times 7\hbox {$^{\prime \prime }$}$). The laboratory wavelength, emission line identification and multiplet number are given in columns 1-3, respectively. Columns 4-9 present the observed line fluxes $F(\lambda )$ and the dereddened fluxes $I(\lambda )$ after correction for interstellar extinction for the three different regions, respectively. All fluxes are given relative to H$\beta$, on a scale where ${\rm H}\beta=100$. To extract the observed line fluxes, we applied a single Gaussian profile to each line. The logarithmic extinction $c({\rm H}\beta)$ was calculated from the Balmer flux ratio H$\alpha$/H$\beta$. However, we adopted the extinction $c$(H$\beta$)$=0.989$ derived by Wang & Liu (2007) for the main shell since the H$\alpha$ emission line was saturated over the main shell area.