J/A+A/687/A123ivo://CDS.VizieR/J/A+A/687/A123doi:10.26093/cds/vizier.36870123CDSMiranda L.F.Vazquez R.Olguin L.Guillen P.F.Matias J.M.2024-11-21T20:01:54Z2024-07-02T08:24:04ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frplanetary-nebulaevisible-astronomyspectroscopyMe 2-1 is a high-excitation planetary nebula whose morphology and physical structure have not yet been investigated. We present narrow-band images in several emission lines, and high- and intermediate-resolution long-slit spectra aimed at investigating its morphology and 3D structure, and its physical parameters and chemical abundances. By applying deconvolution techniques to the images, we identified in Me 2-1 an elliptical ring, two elongated, curved structures (caps) that contain three pairs of bright point-symmetric knots (PS-knots), a shell interior the ring, and a faint halo or attached shell. The caps are observed in all images while the PS-knots only in the low-excitation emission line ones. These structures are also identified in the high-resolution long-slit spectra, hence allowing us to study their morphokinematics. The 3D reconstruction shows that Me 2-1 consists of a ring seen almost pole-on, and a virtually spherical shell, to which the caps and PS-knots are attached. Caps and PS-knots most probably trace the sites where high-velocity collimated bipolar outflows, ejected along a wobbling axis, collide with the spherical shell, are slowed down, and remain attached to it. Although the main excitation mechanism in Me 2-1 is found to be photoionization, a contribution of shocks in the PS-knots is suggested by their emission line ratios. The combination of collimated outflows and a ring with a spherical shell is unusual among planetary nebulae. We speculate that two planets, each with lesser than one Jupiter mass, could be involved in the formation of Me 2-1 if both enter a common envelope evolution during the AGB phase of the progenitor: a planet is tidally disrupted forming an accretion disk around the central star, from which collimated bipolar outflows are ejected, the other planet survives causing wobbling of the accretion disk. The physical parameters and chemical abundances obtained from our intermediate resolution spectrum are similar to those obtained in previous analysis, with the abundances also pointing to a low-mass progenitor for Me 2-1.2024A&A...687A.123Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/687/A123CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/687/A123https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/687/A123http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/687/A123https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/687/A123https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/687/A123http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/687/A123GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/687/A123/list (List of fits images and spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/687/A123/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/687/A123/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/687/A123/list?GETtext/xml+votable180.050000true230.58042-23.625280.0055555555555555566/44416https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/687/A123?format=asciiOpticaldefaultJ/A+A/687/A123/listList of fits images and spectraNxNumber of pixels along X-axismeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainscale? Scale of the imagearcsec/pixinstr.scalefloatnullableNy? Number of pixels along Y-axismeta.numberintnullableObs.dateObservation datetime.epoch;obsnullableblambda? Lower value of wavelength interval for the spectra0.1nmem.wlfloatnullableBlambda? Upper value of wavelength interval for the spectra0.1nmem.wlfloatnullabledlambda? Wavelength resolution for the spectra0.1nmspect.resolutiondoublenullablesizeSize of FITS fileKibytephys.size;meta.fitsintspShow the spectrummeta.ref.urlcharFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar