J/A+A/658/A17ivo://CDS.VizieR/J/A+A/658/A17doi:10.26093/cds/vizier.36580017CDSSantander-Garcia M.Jones D.Alcolea J.Bujarrabal V.Wesson R.2022-03-21T09:39:31Z2022-01-26T08:52:00ZCDS support team

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

cds-question@unistra.frplanetary-nebulaeco-line-emissionvisible-astronomyh-alpha-photometryMost planetary nebulae (PNe) show beautiful, axisymmetric morphologies despite their progenitor stars being essentially spherical. Close binarity is widely invoked to help eject an axisymmetric nebula, after a brief phase of engulfment of the secondary within the envelope of the Asymptotic Giant Branch (AGB) star, known as the common envelope (CE). The evolution of the AGB would thus be interrupted abruptly, its still quite massive envelope being rapidly ejected to form the PN, which a priori would be more massive than a PN coming from the same star, were it single. We aim at testing this hypothesis by investigating the ionised and molecular masses of a sample consisting of 21 post-CE PNe, roughly one fifth of the known total population of these objects, and comparing them to a large sample of 'regular' (i.e. not known to arise from close-binary systems) PNe. We have gathered data on the ionised and molecular content of our sample from the literature, and carried out molecular observations of several previously unobserved objects. We derive the ionised and molecular masses of the sample by means of a systematic approach, using tabulated, dereddened H-beta fluxes for finding the ionised mass, and ^12^CO J=2-1 and J=3-2 observations for estimating the molecular mass. There is a general lack of molecular content in post-CE PNe. Our observations only reveal molecule-rich gas around NGC 6778, distributed into a low-mass, expanding equatorial ring lying beyond the ionised broken ring previously observed in this nebula. The only two other objects showing molecular content (from the literature) are NGC 2346 and NGC 7293. Once we derive the ionised and molecular masses, we find that post-CE PNe arising from Single-Degenerate (SD) systems are just as massive, on average, as the 'regular' PNe sample, whereas post-CE PNe arising from Double-Degenerate (DD) systems are considerably more massive, and show substantially larger linear momenta and kinetic energy than SD systems and `regular' PNe. Reconstruction of the CE of four objects, for which a wealth of data on the nebulae and complete orbital parameters are available, further suggests that the mass of SD nebulae actually amounts to a very small fraction of the envelope of their progenitor stars. This leads to the uncomfortable question of where the rest of the envelope is and why we cannot detect it in the stars' vicinity, thus raising serious doubts on our understanding of these intriguing objects.2022A&A...658A..17Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/658/A17CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/658/A17https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/658/A17http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/658/A17https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/658/A17https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/658/A17http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/658/A17GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalRadiodefaultJ/A+A/658/A17/table4-A1Ionised and molecular masses of post-common-envelope (table 4) and regular comparison (table A1) PNerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSampPNe type (Post-Common-Envelope from table 4 or regular from table A1)src.classcharPNGGalactic PN designationmeta.idcharNameCommon PN namemeta.id;meta.maincharDistDistance to the PNkpcpos.distancefloatE_DistPositive (upper) error on distancekpcstat.error;stat.maxfloate_DistNegative (lower) error on distancekpcstat.errorfloatMionIonised masssolMassphys.massfloatE_MionPositive (upper) error on ionised masssolMassstat.error;stat.maxfloate_MionNegative (lower) error on ionised masssolMassstat.errorfloatl_Mmol[<] Upper limit flag on Mmolmeta.code.errorcharMmolMolecular mass (or upper limit, see flag)solMassphys.massfloate_Mmol? Error on molecular mass, only if Mmol is not an upper limitsolMassstat.errorfloatnullableJ/A+A/658/A17/tableb1Parameters used to estimate the masses of the whole sampleNameCommon PN namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintnElectronic densitycm**-3phys.densityintE_n? Positive (upper) error on densitycm**-3stat.error;stat.maxintnullablee_n? Negative (lower) error on densitycm**-3stat.errorintnullableTeElectronic temperature (1)kKphys.temperaturefloatE_Te? Positive (upper) error on temperaturekKstat.error;stat.maxfloatnullablee_Te? Negative (lower) error on temperaturekKstat.errorfloatnullableDistDistance to the PNkpcpos.distancefloatE_DistPositive (upper) error on distancekpcstat.error;stat.maxfloate_DistNegative (lower) error on distancekpcstat.errorfloatDiamaPN diameter along major axisarcsecphys.angSizefloatDiambPN diameter along minor axisarcsecphys.angSizefloatvexp? PN characteristic expansion velocitykm/sphys.veloc.expansionfloatnullablelogS(Ha)Logarithm of H-alpha dereddened fluxlog(mW.m**-2.sr**-1)phot.flux;em.line.Halphafloate_logS(Ha)Error on the logarithmic H-alpha fluxlog(mW.m**-2.sr**-1)stat.errorfloatTelTelescope used for CO observationsinstr.setup;obscharTransCO rotational (J) transition usedphyscharrms? Sensitivity on CO non-detectionmKstat.errorfloatnullableInt? CO intensity on single-pointingK.km/sphot.flux.densityfloatnullableFlux? CO total fluxK.km.s**-1.arcsec**2phot.fluxfloatnullableRefReferences (in refs.dat file)meta.refcharJ/A+A/658/A17/refsReferencesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference codemeta.noteintBibCodeBibCodemeta.bib.bibcodecharAutAuthors' namemeta.id;meta.maincharComCommentsmeta.notechar