Unveiling compact planetary nebulae: Broad-band survey analysis and LAMOST confirmation

Abstract

Planetary nebulae (PNe) are pivotal for advancing our knowledge of stellar evolution and galactic chemical enrichment. Recent progress in surveys and data analysis has revolutionized PN research, leading to the discovery of new objects and deeper insights into their properties. We have devised a novel photometric selection method, integrating GAIA and Pan-STARRS photometry, to identify compact PN candidates. This approach utilizes color-color diagrams, specifically (G-g) versus (GBP-GRP) and (G-r) versus (GBP-GRP), as primary criteria for candidate selection. The subsequent verification step involves confirming these candidates through LAMOST spectroscopic data. By cross-referencing a comprehensive dataset of PNe, GAIA, Pan-STARRS, and LAMOST DR7 spectra, we explore the potential of our approach and the crucial role played by these surveys in PN research. The LAMOST spectra provide compelling evidence supporting our selection criteria, especially for compact PNe characterized by strong emission lines and low continuum. Applying these criteria to a catalog of emission line objects, we have selected a PN candidate. Detailed analysis of its LAMOST spectrum unveiled classical Balmer emission lines and high-ionization lines (He II, [Ar V], [Ar III], [Ne III]), characteristic of high-ionization PNe, without low-excitation lines. Using the photoionization code Cloudy, our modeling revealed parameters including an ionizing source temperature of 180x10^3 K, luminosity around 3400 Lsun, and gas abundances encompassing various elements. Comparing the PNe evolution track, the progenitor star was estimated to have a mass of 2 Msun. Our findings show strong promise for separating compact PNe from other objects and provide a robust framework for further exploration of these surveys in the context of planetary nebulae.