- ID:
- ivo://CDS.VizieR/J/A+A/552/A74
- Title:
- NIR photometry of Galactic PNe with VVV Survey
- Short Name:
- J/A+A/552/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Aperture photometry of known PNe in the VVV area was retrieved from source catalogues. 579 PNe were selected from the VVV (VISTA Variables in the Via Lactea) survey catalogue. Of these 353 present near-infrared photometry, 75 are highly extended sources, and 123 PNe could not be related to any source in the VVV images, the remainder are sources which NIR emission of the PN is detected in the frames, but there are no photometric data in the VSA database.
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- ID:
- ivo://CDS.VizieR/J/ApJ/831/L3
- Title:
- NIR spectra of 10 PNe in LMC and SMC
- Short Name:
- J/ApJ/831/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present near-infrared spectra of 10 planetary nebulae (PNe) in the Large and Small Magellanic Clouds (LMC and SMC), acquired with the FIRE and GNIRS spectrometers on the 6.5 m Baade and 8.1 m Gemini South Telescopes, respectively. We detect Se and/or Kr emission lines in eight of these objects, the first detections of n-capture elements in Magellanic Cloud PNe. Our abundance analysis shows large s-process enrichments of Kr (0.6-1.3 dex) in the six PNe in which it was detected, and Se is enriched by 0.5-0.9 dex in five objects. We also estimate upper limits to Rb and Cd abundances in these objects. Our abundance results for the LMC are consistent with the hypothesis that PNe with 2-3 M_{\sun}_ progenitors dominate the bright end of the PN luminosity function in young gas-rich galaxies. We find no significant correlations between s-process enrichments and other elemental abundances, central star temperature, or progenitor mass, though this is likely due to our small sample size. We determine S abundances from our spectra and find that [S/H] agrees with [Ar/H] to within 0.2 dex for most objects, but is lower than [O/H] by 0.2-0.4 dex in some PNe, possibly due to O enrichment via third dredge-up. Our results demonstrate that n-capture elements can be detected in PNe belonging to nearby galaxies with ground-based telescopes, allowing s-process enrichments to be studied in PN populations with well-determined distances.
- ID:
- ivo://CDS.VizieR/J/A+AS/102/251
- Title:
- Objective-prism survey of em. objects in M31
- Short Name:
- J/A+AS/102/251
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using GRENS plates taken at the Canada-France-Hawaii telescope, we have searched almost the whole extent of M31 for small-diameter objects with strong emission lines. Most are planetary nebulae candidates, but there are also many Wolf-Rayet star candidates and small HII regions or compact parts of large HII regions. A catalogue is presented with a cross-identification with previous catalogues. Many new planetary nebulae and Wolf-Rayet candidates are found. Their distribution is compared with those of other tracers in M31. In particular the distribution of planetary nebulae candidates is compared with that of the integrated blue light and we confirm the result obtained by Jacoby ( 1980ApJS...42....1J) and Ciardullo et al. (1989ApJ...339...53C): the number of planetary nebulae per unit total luminosity is a constant throughout the disk of M31. The Wolf- Rayet star candidates are concentrated in the well-known ring of star formation; their total number is estimated as 300 within the limit of detection of the deepest existing surveys, but this may still be an underestimate of the true number.
- ID:
- ivo://CDS.VizieR/J/A+AS/125/419
- Title:
- Obscured AGB in Magellanic Clouds. I.
- Short Name:
- J/A+AS/125/419
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have selected 198 IRAS sources in the Large Magellanic Cloud, and 11 in the Small Magellanic Cloud, which are the best candidates to be mass-loosing AGB stars (or possibly post-AGB stars). We used the catalogues of Schwering & Israel (1990, Cat. II/181) and Reid et al. (1990, Cat. J/ApJ/348/98). They are based on the IRAS pointed observations and have lower detection limits than the Point Source Catalogue. We also made cross-identifications between IRAS sources and optical catalogues.
- ID:
- ivo://CDS.VizieR/J/ApJ/778/16
- Title:
- Observations of HCO^+^ in NGC 7293
- Short Name:
- J/ApJ/778/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The J=1->0 transition of HCO^+^ at 89GHz has been mapped across the Helix Nebula (NGC 7293) with 70" spatial resolution (1.68km/s velocity resolution) using the Arizona Radio Observatory 12m telescope. This work is the first large-scale mapping project of a dense gas tracer (n(H_2_)~10^5^/cm3) in old planetary nebulae. Observations of over 200 positions encompassing the classical optical image were conducted with a 3{sigma} noise level of ~20mK. HCO^+^ was detected at most positions, often exhibiting multiple velocity components indicative of complex kinematic structures in dense gas. The HCO^+^ spectra suggest that the Helix is composed of a bipolar, barrel-like structure with red- and blue-shifted halves, symmetric with respect to the central star and oriented ~10{deg} east from the line of sight. A second bipolar, higher velocity outflow exists as well, situated along the direction of the Helix "plumes." The column density of HCO^+^ across the Helix is N_tot_~1.5x10^10^-5.0x10^11^/cm2, with an average value N_ave_~1x10^11^/cm2, corresponding to an abundance, relative to H_2_, of f~1.4x10^-8^. This value is similar to that observed in young PN, and contradicts chemical models, which predict that the abundance of HCO^+^ decreases with nebular age. This study indicates that polyatomic molecules readily survive the ultraviolet field of the central white dwarf, and can be useful in tracing nebular morphology in the very late stages of stellar evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/431/523
- Title:
- Observing log of 9 planetary nebulae
- Short Name:
- J/A+A/431/523
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of the infrared fine-structure lines of [Si II] (34.8{mu}m), [O I] (63.2 and 145.5{mu}m) and [C II] (157.7{mu}m) obtained with the ISO SWS and LWS spectrographs of nine Planetary Nebulae (PNe). These lines originate in the Photo-Dissociation Regions (PDRs) associated with the nebulae and provide useful information on the evolution and excitation conditions of the ejected material in these regions. In order to interpret the observations, the measured line intensities have been compared with those predicted by photo-dissociation models.
- ID:
- ivo://CDS.VizieR/J/A+AS/137/157
- Title:
- O III recombination coefficients
- Short Name:
- J/A+AS/137/157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We calculate effective recombination coefficients for the formation of the 5g-4f lines of O III in the intermediate coupling scheme. Photoionization data for the 5g levels calculated using the R-matrix method are used to derive their recombination coefficients. Cascading from higher states is included, allowing for the effects of finite electron density in a hydrogenic approximation. We explicitly include the distribution of population between the two ground levels of O^3+^ in the calculation of the line intensities. The results are presented as a simple programmable formula allowing the calculation of recombination line intensities for electron temperatures, T_e_ in the range 5000-20000K and electron densities, N_e_ in the range 10^2^-10^6^cm^-3^.
- ID:
- ivo://CDS.VizieR/J/ApJ/614/745
- Title:
- Optical and IUE spectra of NGC 7026
- Short Name:
- J/ApJ/614/745
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigated spectroscopic data of the extended planetary nebula NGC 7026 in the wavelengths 3700-10050{AA}, secured with the Hamilton Echelle Spectrograph at Lick Observatory. This optical wavelength spectrum has been analyzed along with the International Ultraviolet Explorer (IUE) UV spectral data.
- ID:
- ivo://CDS.VizieR/J/other/RMxAA/37.115
- Title:
- Optical coordinates of southern PNe
- Short Name:
- J/other/RMxAA/37
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A homogeneous set of new measurements of nearly all (995 out of 1007) objects from the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Cat. <V/100>) or in the first supplement of this catalogue in the area covered by the DENIS survey (<B/denis>) ({delta}<+2{deg}) is given here. A list of 24 new and 27 wrong cross-identifications with sources in the IRAS PSC catalogue and some confusion in the literature is listed as well.
- ID:
- ivo://CDS.VizieR/J/A+A/563/A63
- Title:
- Optical spectra of new low-excitation PNs
- Short Name:
- J/A+A/563/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present mid-resolution spectroscopic observations of four new planetary nebula (PN) candidates selected from the INT/WFC Photometric H-alpha Survey of the Northern Galactic Plane (IPHAS) and Deep Sky Hunter (DSH) catalogues. The PN status of these objects was confirmed by mid-resolution spectra. Based on the locations of these objects in the log(H-alpha/[NII]) versus log (H-alpha/[SII]) diagnostic diagram, these sources are evolved low- excitation PNs.
