A Carbon-rich Hot Bubble in the Planetary Nebula NGC 5189

Abstract We present the discovery of extended X-ray emission from the planetary nebula (PN) NGC 5189 around the [WO1]-type WD 1330−657 with XMM-Newton. The X-ray-emitting gas fills the cavities detected in the Hubble Space Telescope [O iii] narrowband image and presents a limb-brightened morphology toward the outer edges of the east and west lobes. The bulk of the X-ray emission is detected in the soft (0.3–0.7 keV) band with the XMM-Newton EPIC spectra dominated by the C vi Lyα line at 0.37 keV (=33.7 Å). Spectral analysis resulted in carbon and neon abundances 38 and 6 times their solar values, with a plasma temperature of kT = 0.14 ± 0.01 keV (T = 1.6 × 106 K) and X-ray luminosity of L X = (2.8 ± 0.8) × 1032 erg s−1. NGC 5189 is an evolved and extended PN (≲0.70 pc in radius), thus, we suggest that the origin of its X-ray emission is consistent with the born-again scenario in which the central star becomes carbon-rich through an eruptive very late thermal pulse, subsequently developing a fast, carbon-rich wind powering the X-ray emission as suggested for A 30 and A 78.