Planetary Nebulae in the eROSITA eRASS1 catalog

Some planetary nebulae (PNe) host X-ray-emitting hot bubbles shaped by stellar wind interactions and/or harbor X-ray-emitting central stars due to accretion, shocks within their fast stellar winds, or even chromospheric emission from binary companions. In both cases, the properties of the X-ray emission critically probe late-stages of stellar evolution for such low- and intermediate-mass stars. While extant Chandra and XMM-Newton observations have detected X-ray emission in PNe, the numbers known remain very small ($\sim 40$) compared to the overall Galactic PNe population ($\sim 4000$). We have initiated a project aimed at increasing the sample of known PNe with X-ray emission using both current and new space-based X-ray telescopes such as the Einstein probe. To further investigate their X-ray properties to elucidate what drives current X-ray PN detections, we have cross-searched the SRG {\it eROSITA-DE} eRASS1 source catalogue and Hong Kong (HASH) PNe Database. Five known X-ray PNe have been detected (Abell,30, NGC,2392, NGC,3242, NGC,5315, and LoTr,5), two new X-ray PNe are revealed (IC,1297 and NGC,2867), one (K,1-27) is removed from previous X-ray compilations, and another 11 previously detected X-ray emitting PNe are not recovered. A comparison of the X-ray flux of detected and undetected X-ray PNe reveals that eROSITA eRASS1 is sensitive to PNe with X-ray fluxes larger than $\approx 2\times {10}^{-14}$ erg~cm${}^{-2}$~s${}^{-1}$. The frequency of occurrence is $\simeq$0.5% among the 1430 HASH True PNe in the eRASS1 footprint.