- ID:
- ivo://CDS.VizieR/J/A+A/640/A10
- Title:
- Catalogue of planetary nebulae central stars
- Short Name:
- J/A+A/640/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Planetary nebulae represent a potential late stage of stellar evolution, however, their central stars (CSPNe) are relatively faint and, therefore, pertinent information is available for merely <20% of the Galactic sample. Consequently, the literature was surveyed to construct a new catalogue of 620 CSPNe featuring important spectral classifications and information. The catalogue supersedes the existing iteration by 25% and includes physical parameters such as luminosity, surface gravity, temperature, magnitude estimates, and references for published spectra. The marked statistical improvement enabled the following pertinent conclusions to be determined: the H-rich/H-poor ratio is 2:1, there is a deficiency of CSPNe with types [WC 5-6], and nearly 80% of binary central stars belong to the H-rich group. The last finding suggests that evolutionary scenarios leading to the formation of binary central stars interfere with the conditions required for the formation of H-poor CSPN. Approximately 50% of the sample with derived values of logL, logT_eff_, and logg, exhibit masses and ages consistent with single stellar evolutionary models. The implication is that single stars are indeed able to form planetary nebulae. Moreover, it is shown that H-poor CSPNe are formed by higher mass progenitors.
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- ID:
- ivo://CDS.VizieR/J/A+A/526/A6
- Title:
- Central stars of galactic planetary nebulae
- Short Name:
- J/A+A/526/A6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There are more than 3000 confirmed and probable known Galactic planetary nebulae (PNe), but central star spectroscopic information is available for only 13% of them. We undertook a spectroscopic survey of central stars of PNe at low resolution and compiled a large list of central stars for which information was dispersed in the literature. We present a catalogue of 492 confirmed and probable CSPN and provide a preliminary spectral classification for 45 central star of PNe. This revises previous values of the proportion of CSPN with atmospheres poor in hydrogen in at least 30% of cases and provide statistical information that allows us to infer the origin of H-poor stars. Based on data collected at the Complejo Astronomico El Leoncito (CASLEO), which is operated under agreement between the Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina y Universidades Nacionales de La Plata, Cordoba y San Juan, Argentina.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A172
- Title:
- Central stars of planetary nebulae. II.
- Short Name:
- J/A+A/531/A172
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- There are more than 3000 confirmed and probably known Galactic planetary nebulae (PNe), but central star spectroscopic information is available for only 13% of them. We have undertaken a spectroscopic survey of the central stars in PNe to identify their spectral types. We performed spectroscopic observations at low resolution with the 2-m telescope at CASLEO, Argentina. We present the spectra of 46 central stars of PNe, most of them are OB-type and emission-line stars.
- ID:
- ivo://CDS.VizieR/J/A+A/638/A103
- Title:
- Central stars of planetary nebulae in Gaia DR2
- Short Name:
- J/A+A/638/A103
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate distance measurements are fundamental to the study of planetary nebulae (PNe) but they have long been elusive. The most accurate and model-independent distance measurements for galactic PNe come from the trigonometric parallaxes of their central stars, which were only available for a few tens of objects prior to the Gaia mission. The accurate identification of PN central stars (CSPNe) in the Gaia source catalogues is a critical prerequisite for leveraging the unprecedented scope and precision of the trigonometric parallaxes measured by Gaia. Our aim is to build a complete sample of PN central star detections with minimal contamination. We developed and applied an automated technique based on the likelihood ratio method to match candidate central stars in Gaia Data Release 2 (DR2) to known PNe in the Hong Kong/AAO/Strasbourg H{alpha} (HASH) PN catalogue (Parker et al. 2016, 2016JPhCS.728c2008P), taking into account the BP-RP colours of the Gaia sources as well as their positional offsets from the nebula centres. These parameter distributions for both true central stars and background sources were inferred directly from the data. We present a catalogue of over 1000 Gaia sources that our method has automatically identified as likely PN central stars. We demonstrate how the best matches enable us to trace nebula and central star evolution and to validate existing statistical distance scales, and we discuss the prospects for further refinement of the matching based on additional data. We also compare the accuracy of our catalogue to that of previous works.
- ID:
- ivo://CDS.VizieR/J/MNRAS/368/1959
- Title:
- Chemical abundances for Hf 2-2
- Short Name:
- J/MNRAS/368/1959
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-quality optical spectroscopic observations of the planetary nebula (PN) Hf 2-2. The spectrum exhibits many prominent optical recombination lines (ORLs) from heavy-element ions. Analysis of the H I and He I recombination spectrum yields an electron temperature of ~900K, a factor of 10 lower than given by the collisionally excited [O III] forbidden lines. The ionic abundances of heavy elements relative to hydrogen derived from ORLs are about a factor of 70 higher than those deduced from collisionally excited lines (CELs) from the same ions, the largest abundance discrepancy factor (adf) ever measured for a PN.
- ID:
- ivo://CDS.VizieR/J/A+A/567/A12
- Title:
- Chemical abundances in Galactic PNe
- Short Name:
- J/A+A/567/A12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new low-resolution (R~800) optical spectra of 22 Galactic PNe with Spitzer spectra. These data are combined with recent optical spectroscopic data available in the literature to construct representative samples of compact (and presumably young) Galactic disc and bulge PNe with Spitzer spectra. Attending to the nature of the dust features seen in their Spitzer spectra, Galactic disc and bulge PNe are classified according to four major dust types (oxygen chemistry or OC, carbon chemistry or CC, double chemistry or DC, featureless or F) and subtypes (amorphous and crystalline, and aliphatic and aromatic). Nebular gas abundances of He, N, O, Ne, S, Cl, and Ar, as well as plasma parameters (e.g. Ne, Te) are homogeneously derived and we study the median chemical abundances and nebular properties in Galactic disc and bulge PNe depending on their Spitzer dust types and subtypes. A comparison of the derived median abundance patterns with AGB nucleosynthesis predictions show mainly that i) DC PNe, both with amorphous and crystalline silicates, display high-metallicity (solar/supra-solar) and the highest He abundances and N/O ratios, suggesting relatively massive (~3-5M_{sun}_) hot bottom burning AGB stars as progenitors; ii) PNe with O-rich and C-rich unevolved dust (amorphous and aliphatic) seem to evolve from subsolar metallicity (z~0.008) and lower mass (<3M_{sun}_) AGB stars; iii) a few O-rich PNe and a significant fraction of C-rich PNe with more evolved dust (crystalline and aromatic, respectively) display chemical abundances similar to DC PNe, suggesting that they are related objects. A comparison of the derived nebular properties with predictions from models combining the theoretical central star evolution with a simple nebular model is also presented. Finally, a possible link between the Spitzer dust properties, chemical abundances, and evolutionary status is discussed.
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/4070
- Title:
- Chemical abundances in the PN Wray16-423
- Short Name:
- J/MNRAS/452/4070
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We performed a detailed analysis of elemental abundances, dust features, and polycyclic aromatic hydrocarbons (PAHs) in the C-rich planetary nebula (PN) Wray16-423 in the Sagittarius dwarf spheroidal galaxy, based on a unique data set taken from the Subaru/HDS, MPG/ESO FEROS, HST/WFPC2, and Spitzer/IRS. We performed the first measurements of Kr, Fe, and recombination O abundance in this PN. The extremely small [Fe/H] implies that most Fe atoms are in the solid phase, considering into account the abundance of [Ar/H]. The Spitzer/IRS spectrum displays broad 16-24 {mu}m and 30 {mu}m features, as well as PAH bands at 6-9 and 10^-14^ {mu}m. The unidentified broad 16-24 {mu}m feature may not be related to iron sulphide (FeS), amorphous silicate, or PAHs. Using the spectral energy distribution model, we derived the luminosity and effective temperature of the central star, and the gas and dust masses. The observed elemental abundances and derived gas mass are in good agreement with asymptotic giant branch nucleosynthesis models for an initial mass of 1.90 M_{sun}_ and a metallicity of Z=0.004. We infer that respectively about 80, 50, and 90 per cent of the Mg, S, and Fe atoms are in the solid phase. We also assessed the maximum possible magnesium sulphide (MgS) and iron-rich sulphide (Fe50S) masses and tested whether these species can produce the band flux of the observed 30 {mu}m feature. Depending on what fraction of the sulphur is in sulphide molecules such as CS, we conclude that MgS and Fe50S could be possible carriers of the 30 {mu}m feature in this PN.
- ID:
- ivo://CDS.VizieR/J/A+A/423/199
- Title:
- Chemical abundances of planetary nebulae
- Short Name:
- J/A+A/423/199
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we report new observations and derive chemical abundances for a sample of 26 planetary nebulae (PN) located in the anti-center direction. Most of these nebulae are far away objects, located at galactocentric distances greater than about 8kpc, so that they are particularly useful for the determination of the radial gradients at large distances from the galactic center.
- ID:
- ivo://CDS.VizieR/J/A+A/280/581
- Title:
- Chemical abundances of PNe
- Short Name:
- J/A+A/280/581
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- All modern determinations of chemical abundances of He/H, O/H, C/H, N/H and Ne/H in 277 galactic Planetary Nebulae have been used to update our knowledge of the chemical behavior of Planetary Nebulae, as a whole and in Peimbert's groups. The data have been used to set up the problem of the chemical gradients in the Galaxy from Planetary Nebulae. The Interstellar Medium has been found to be more inhomogeneous in the past epochs of the Galaxy than in the present time.
- ID:
- ivo://CDS.VizieR/J/A+A/463/265
- Title:
- Chemical compositions of 48 WR planetary nebulae
- Short Name:
- J/A+A/463/265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Chemical compositions and other properties of planetary nebulae around central stars of spectral types [WC], [WO], and wels are compared with those of "normal" central stars, in order to clarify the evolutionary status of each type and their interrelation. We use plasma diagnostics to derive from optical spectra the plasma parameters and chemical compositions of 48 planetary nebulae. We also reanalyze the published spectra of a sample of 167 non-WR PN. The results as well as the observational data are compared in detail with those from other studies of the objects in common.
