NGC6543 and NGC6552 of the North Ecliptic Pole

Figure 1 - DSS (POSS2) view of the NEP region; the width is 0.5 deg.	Figure 2 - IRAC view of NGC6543 (center) and NGC6552 (left side). The data was taken such that IRAC 1-4 fully covers NGC6543, but NGC6552 is only covered by IRAC-1.

I. Introduction

The tip of the north ecliptic pole (NEP) is blessed with two interesting extended sources: NGC6543 and NGC6552. The former is a very bright planetary nebula, aka the "Cat's Eye", that is truly spectacular with HST. The latter is a barred spiral galaxy with a Sy2 nucleus. This document presents some Spitzer imaging of both objects to demonstrate the impact these objects (most notably N6543) will have on WISE imaging of the pole ; see Fig. 2 above.

Table 1 - Coordinates

NGC6543 (PN)
Ref Frame	longitude (deg)	latitude (deg)
equatorial (J2000)	269.639115	66.633190
ecliptic (J2000)	153.010897	89.839375
NGC6552 (SB)
Ref Frame	longitude (deg)	latitude (deg)
equatorial (J2000)	270.030375	66.615083
ecliptic (J2000)	77.499141	89.944302

Notes to Table 1: Coordinates are taken from the NASA Extragalactic Database.
NGC6552 has a helio. radial velocity of 7942 km/s.

II. NGC6543

This source is relatively bright at near-infrared wavelengths and positively luminous at mid-infrared wavelengths (see spectrum below). The 2MASS XSC lists 8.97, 9.08, 8.34 mag for J, H, Ks, respectively. The IRAS FSC measurements are 7.522, 110.1, 125.5 and 60.9 Jy for 12, 25, 60 and 100 um, respectively. IRAC imaging of the PN reveals a number of electronic and light-scattering artifacts (e.g., banding, ghosts, persistence, droop). The MIPS 24um images are even more horrifying; see below.

Figure 3 - IRAC 8.0um view of NGC6543.	Figure 4 - MIPS 24um view of NGC6543. Note the severe "droop" offsets.	Figure 5 - MIPS 24um "dark" latents.	Figure 6 - ISO SWS spectrum of N6543.

MIPS parameter notes: TargetName: NGC 6543 - 160 cluster; ReqKey: 11412736 (Mark Morris); Fixed Cluster-Offsets; exp. time = 10s, with 2 cycles

III. NGC6552

This well resolved (for 2MASS) galaxy is located roughly 10 arcmin to the east (equatorial) of N6543. Unfortunately, the only Spitzer imaging that covers this galaxy is 3.6 and 5.8um (channels 1,3). We have optical imaging at B (partial coverage), and R-bands to supplement the 2MASS JHK and IRAC 1,3; see images below. Note the large-scale "bar" and red nucleus (Sy2 nucleus), where most of the radio continuum is probably originating. This galaxy will serve well as a secondary 'extended source' calibrator.

Figure 7 - 2MASS JHK image of NGC6552.	Figure 8 - 2MASS JH + IRAC1 image of NGC6552.	Figure 9 - R-band + 2MASS JH + IRAC-1 image of NGC6552.	Figure 10 - 1.49 GHz (20cm) radio continuum map (from NED).