J/A+A/617/A31ivo://CDS.VizieR/J/A+A/617/A31doi:10.26093/cds/vizier.36170031CDSAlonso-Albi T.Riviere-Marichalar P.Fuente A.Pacheco-Vazquez S.,Montesinos B.Bachiller R.Trevino-Morales S.P.2018-10-01T13:10:51Z2018-09-12T11:27:27ZCDS support team

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

cds-question@unistra.frprotostarsbe-starspre-main-sequence-starsinterferometryTo our knowledge, R Mon is the only B0 star in which a gaseous Keplerian disk has been detected. However, there is some controversy about the spectral type of R Mon. Some authors propose that it could be a later B8e star, where disks are more common. Our goal is to re-evaluate the R Mon spectral type and characterize its protoplanetary disk. The spectral type of R Mon has been re-evaluated using the available continuum data and UVES emission lines. We used a power-law disk model to fit previous ^12^CO 1-0 and 2-1 interferometric observations and the PACS CO data to investigate the disk structure. Interferometric detections of ^13^CO J=1-0, HCO^+^ 1-0, and CN 1-0 lines using the IRAM Plateau de Bure Interferometer (PdBI) are presented. The HCN 1-0 line was not detected. Our analysis confirms that R Mon is a B0 star. The disk model compatible with the ^12^CO 1-0 and 2-1 interferometric observations falls short of predicting the observed fluxes of the 14<Ju<31 PACS lines; this is consistent with the scenario in which some contribution to these lines is coming from a warm envelope and/or UV-illuminated outflow walls. More interestingly, the upper limits to the fluxes of the Ju>31 CO lines suggest the existence of a region empty of CO at R<=20au in the proto-planetary disk. The intense emission of the HCO^+^ and CN lines shows the strong influence of UV photons on gas chemistry. The observations gathered in this paper are consistent with the presence of a transition disk with a cavity of Rin>=20 au around R Mon. This size is similar to the photoevaporation radius that supports the interpretation that UV photoevaporation is main disk dispersal mechanism in massive stars2018A&A...617A..31Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/617/A31CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/617/A31https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/617/A31http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/617/A31https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/617/A31https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/617/A31http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/617/A31GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/617/A31/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/617/A31/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/617/A31/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/617/A31/list?GETtext/xml+votable180.050000true99.791598.735990.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/617/A316/23636https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/617/A31?format=asciidefaultJ/A+A/617/A31/listList of fits imagesNyNumber of pixels along Y-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.mainNxNumber of pixels along X-axismeta.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fits