2023/12/07 by C. Sánchez Contreras, Daniel Tafoya, Contreras, C. Sánchez +9
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2312.04188
openalex publication_date 2023/12/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report on recent results from our successful and pioneering observational program with ALMA to study emerging ultracom pact HII regions of pre-Planetary Nebulae (pPNe) using mm-wavelength recombination lines (mRRLs) as new optimal tracers. We focus on our study of two poster-child pPNe, namely, M2-9 and CRL618. We reveal the structure and kinematics of the en igmatic inner nebular regions of these objects with an unprecedented angular resolution down to 20-30mas (~15-30AU). For both targets, the ionized central regions are elongated along the main symmetry axis of the large-scale nebulae, consiste nt with bipolar winds, and show notable axial velocity gradients with expansion velocities of up to ~100km/s. The H30a pr ofiles exhibit time variability, reflecting changes in the physical properties and kinematics on scales of a few years. O ur ongoing analysis employs 3D, non-LTE radiative transfer modeling, providing a detailed description of the innermost la yers of these well known pPNe with exceptional clarity.