Uncovering the structure and kinematics of the ionized core of M\,2-9 with ALMA
arXiv:2411.03825 · doi:10.1051/0004-6361/202451669
Abstract
We present interferometric observations at 1 and 3\,mm with the Atacama Large Millimeter Array (ALMA) of the free-free continuum and mm-wavelength recombination line (mRRL) emission of the ionized core (within $\lsim$130\,au) of the young Planetary Nebula (PN) candidate M\,2-9.These inner regions are concealed in the vast majority of similar objects. A spectral index for the mm-to-cm continuum of 0.9 indicates predominantly free-free emission from an ionized wind, with a minor contribution from warm dust. The mm-continuum emission in M\,2-9 reveals an elongated structure along the main symmetry axis of the large-scale bipolar nebula with a C-shaped curvature surrounded by a broad-waisted component. This structure is consistent with an ionized bent jet and a perpendicular compact dusty disk. The presence of a compact equatorial disk (of radius 50\,au) is also supported by red-shifted CO and \trecem\ absorption profiles observed from the base of the receding north lobe against the compact background continuum. The redshift observed in the CO absorption profiles likely signifies gas infall movements from the disk toward a central source. The mRRLs exhibit velocity gradients along the axis, implying systematic expansion in the C-shaped bipolar outflow. The highest expansion velocities (80\,\kms) are found in two diagonally opposed compact regions along the axis, referred to as the high-velocity spots/shells (HVS), indicating either rapid wind acceleration or shocks at radial distances of 0\farc02-0\farc04 (15-25\,au) from the center. A subtle velocity gradient perpendicular to the lobes is also found, suggestive of rotation. Our ALMA observations detect increased brightness and broadness in the mRRLs... (abridged).
arXiv comment28 pages. Accepted for publication in A&A
References in corpus (30)
- A computer program for fast non-LTE analysis of interstellar line spectra
- A Grid of NLTE Line-Blanketed Model Atmospheres of Early B-type Stars
- Post-Asymptotic Giant Branch Evolution of Low- and Intermediate-Mass Stars. Preliminary Results
- New models for the evolution of Post-Asymptotic Giant Branch stars and Central Stars of Planetary Nebulae
- The Formation of Very Narrow Waist Bipolar Planetary Nebulae
- Mass Transfer and Disc Formation in AGB Binary Systems
- A newly discovered stellar type: dusty post-red giant branch stars in the Magellanic Clouds
- Probing the inner wind of AGB stars: Interferometric observations of SiO millimetre line emission from the oxygen-rich stars R Dor and L2 Pup
- A Massive Bipolar Outflow and a Dusty Torus with Large Grains in the Pre-Planetary Nebula IRAS 22036+5306
- A morpho-kinematic and spectroscopic study of the bipolar nebulae: M 2-9, Mz 3, and Hen 2-104
- Broad Halpha wings in Nebulae around Evolved Stars and in Young Planetary Nebulae
- Collimated Outflow Formation via Binary Stars. 3-D Simulations of AGB Wind and Disk Wind Interactions
- PPN as Explosions: Bullets vs Jets and Nebular Shaping
- The "Twin Jet" Planetary Nebula M2-9
- Bipolar Symbiotic Planetary Nebulae in the Thermal-IR: M2-9, Mz3, and He2-104
- A disk inside the bipolar planetary nebula M2-9
- The evolution of M 2-9 from 2000 to 2010
- A non-LTE radiative transfer model to study ionized outflows and disks. The case of MWC349A
- A pilot search for mm-wavelength recombination lines from emerging ionized winds in pre-planetary nebulae candidates
- Two short mass-loss events that unveil the binary heart of Minkowski's Butterfly Nebula
- HD101584: Circumstellar characteristics and evolutionary status
- Raman Scattered He II Line in the Planetary Nebula M2-9 and the Symbiotic Stars RR Telescopii and He 2-106
- A census of Post-AGB stars in Gaia DR3: evidence for a substantial population of Galactic post-RGB stars
- Structure and dynamics of the inner nebula around the symbiotic stellar system R Aqr
- Origin of the ionized wind in MWC 349A
- Shock excitation of the knots of Hen 3-1475
- Models of the Mass-Ejection Histories of pre Planetary Nebulae. II. The Formation of the Butterfly and its Proboscis in M2-9
- A rotating fast bipolar wind and disk system around the B[e]-type star MWC 922
- Dissecting the central regions of OH 231.8 + 4.2 with ALMA: a salty rotating disk at the base of a young bipolar outflow
- The symbiotic and bipolar nebula M2-9: Morphological variability of the collimated ionized wind arising from the core