- ID:
- ivo://CDS.VizieR/J/A+A/553/A126
- Title:
- Far-UV spectra of PN central stars
- Short Name:
- J/A+A/553/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The occurrence of stellar wind in the central star of a planetary nebula (CSPN) can be revealed by the presence of P Cygni profiles of high-excitation lines overimposed on its stellar continuum. We have examined the entire Far-Ultraviolet Spectroscopic Explorer FUSE archive and merged all useful spectroscopic observations of CSPNe to produce the highest quality spectra that can be used to assess the occurrence of stellar winds. Furthermore, the individual spectra of each CSPN have been compared to search for variability in the P Cygni profile. P Cygni profiles of high-excitation lines have been found in 44 CSPNe, with a clear correlation between the ionization potential of the lines and the effective temperature of the star.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/696/729
- Title:
- Fluxes and abundances of PNe in M33
- Short Name:
- J/ApJ/696/729
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The planetary nebula (PN) population of M33 is studied via multifiber spectroscopy with Hectospec at the MMT. In this paper, we present the spectra of 102 PNe, whereas plasma diagnostic and chemical abundances were performed on the 93 PNe where the necessary diagnostic lines were measured. About 20% of the PNe are compatible with being Type I; the rest of the sample is the progeny of an old disk stellar population, with main sequence masses M<3M_{sun}_ and ages t>0.3Gyr. Our observations do not seem to imply that the metallicity gradient across the M33 disk has flattened considerably with time. We report also the discovery of a PN with Wolf-Rayet features, PN039, belonging the class of late [WC] stars.
- ID:
- ivo://CDS.VizieR/J/A+A/637/A62
- Title:
- Fornax3D. Planetary nebulae automated detection
- Short Name:
- J/A+A/637/A62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extragalactic Planetary Nebulae (PNe) are detectable via relatively strong nebulous [OIII] emission, acting as direct probes into the local stellar population. Due to an apparently universal, invariant magnitude cut-off, PNe are also considered to be a remarkable standard candle for distance estimation. Through detecting PNe within the galaxies, we aim to connect the relative abundances of PNe to the properties of their host galaxy stellar population. By removing the stellar background components from FCC 167 and FCC 219, we aim to produce PN Luminosity Functions (PNLF) of those galaxies, and therefore also estimate the distance modulus to those two systems. Finally, we test the reliability and robustness of the our novel detection and analysis method. It detects the presence of unresolved point sources via their [OIII] 5007{AA} emission, within regions previously unexplored. We model the [OIII] emissions in both the spatial and spectral dimensions together, as afforded to us by the Multi Unit Spectroscopic Explorer (MUSE) and drawing on data gathered as part of the Fornax3D survey. For each source, we inspect the properties of the nebular emission lines present to remove other sources, that could hinder the safe construction of the PNLF, such as supernova remnants and HII regions. As a further step, we characterise any potential limitations and draw conclusions about the reliability of our modelling approach via a set of simulations. Through the application of this novel detection and modelling approach to IFU observations, we report for both galaxies: distance estimates, luminosity specific PNe frequency values. Furthermore, we include an overview into source contamination, galaxy differences and how they may affect the PNe populations in the dense stellar environments.
- ID:
- ivo://CDS.VizieR/J/A+A/653/A167
- Title:
- Fornax3D PNe Catalogue
- Short Name:
- J/A+A/653/A167
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Extragalactic planetary nebulae (PNe) offer a way to determine the distance to their host galaxies thanks to the nearly universal shape of the luminosity function (PNLF). Accurate PNe distance measurements rely on obtaining well- sampled PNLFs and the number of observed PNe scales with the encompassed stellar mass. This means either disposing of wide-field observations or on focusing on the bright central regions of galaxies. In this work we take this second approach and conduct a census of the PNe population in the central regions of galaxies in the Fornax cluster, using VLT/MUSE data for the early- type galaxies observed over the course of the Fornax3D survey. Using such integral-field spectroscopic observations to carefully separate the nebular emission from the stellar continuum, we isolate [OIII] 5007{AA} sources of interest, filter out unresolved impostor sources or kinematic outliers, and present a catalogue of 1350 unique PNe sources across 21 early- type galaxies, which includes their positions, [OIII} 5007{AA} line magnitudes and line-of-sight velocities. Using the PNe catalogued within each galaxy, we present independently-derived distance estimates based on the fit to the entire observed PNLF observed while carefully accounting for the PNe detection incompleteness. With these individual measurements we arrive at an average distance to the Fornax cluster itself of 19.86+/-0.32Mpc ({mu}_PNLF_=31.49+/-0.04mag). Our PNLF distance measurements agree well with previous distances based on surface brightness fluctuations, finding no significant systematic offsets between the two methods as otherwise reported in previous studies.
- ID:
- ivo://CDS.VizieR/J/A+A/656/A110
- Title:
- Gaia EDR3 planetary nebula central star distances
- Short Name:
- J/A+A/656/A110
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Planetary nebulae (PNe) are a brief but important phase of stellar evolution. The study of Galactic PNe has historically been hampered by uncertain distances, but the parallaxes of PN central stars (CSPNe) measured by Gaia are improving the situation. Gaia's Early Data Release 3 (EDR3) offers higher astrometric precision and greater completeness compared to previous releases. Taking advantage of these improvements requires that the CSPNe in the catalogue be accurately identified. We applied our automated technique based on the likelihood ratio method to cross-match known PNe with sources in Gaia EDR3, using an empirically derived position and colour distribution to score candidate matches. We present a catalogue of over 2000 sources in Gaia EDR3 that our method has identified as likely CSPNe or compact nebula detections. We show how the more precise parallaxes of these sources compare to previous PN statistical distances and introduce an approach to combining them to produce tighter distance constraints. We also discuss Gaia's handling of close companions and bright nebulae. Gaia is unlocking new avenues for the study of PNe. The catalogue presented here will remain valid for the upcoming Gaia Data Release 3 (DR3) and thus provide a valuable resource for years to come.
- ID:
- ivo://CDS.VizieR/J/ApJ/724/748
- Title:
- Galactic anticenter PNe and oxygen abundance
- Short Name:
- J/ApJ/724/748
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained spectrophotometric observations of 41 anticenter planetary nebulae (PNe) located in the disk of the Milky Way. Electron temperatures and densities, as well as chemical abundances for He, N, O, Ne, S, Cl, and Ar were determined. Incorporating these results into our existing database of PN abundances (Henry et al., 2004AJ....127.2284H, Milingo et al., 2010, Cat. J/ApJ/711/619) yielded a sample of 124 well-observed objects with homogeneously determined abundances extending from 0.9 to 21kpc in galactocentric distance. We performed a detailed regression analysis which accounted for uncertainties in both oxygen abundances and radial distances in order to establish the metallicity gradient across the disk to be 12+log(O/H)=(9.09+/-0.05)-(0.058+/-0.006)xR_g_, with R_g_ in kpc. While we see some evidence that the gradient steepens at large galactocentric distances, more objects toward the anticenter need to be observed in order to confidently establish the true form of the metallicity gradient.
- ID:
- ivo://CDS.VizieR/J/A+A/447/921
- Title:
- Galactic Open Cluster Candidates
- Short Name:
- J/A+A/447/921
- Date:
- 14 Jan 2022 07:59:11
- Publisher:
- CDS
- Description:
- An inspection of DSS and 2MASS images of selected Milky Way regions led to the discovery of 66 stellar groupings whose morphologies, color-magnitude diagrams and stellar density distributions suggest that these objects are possible open clusters that are not yet listed in any catalogue. For 24 of these, which we consider to be the most likely candidates, we provide extensive descriptions on the basis of 2MASS photometry and their visual impression on DSS and 2MASS. Of those cluster candidates, 9 have fundamental parameters determined by fitting the color-magnitude diagrams with solar metallicity Padova isochrones. Additional 10 cluster candidates have distance moduli and reddenings derived from K magnitudes and (J-K) color indices of helium-burning red clump stars. As an addendum, we provide a list of a number of apparently yet unknown galactic and extragalactic objects which were also discovered during the survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/714/1096
- Title:
- Galactic planetary nebulae
- Short Name:
- J/ApJ/714/1096
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use an extended and homogeneous data set of Galactic planetary nebulae (PNe) to study the metallicity gradients and the Galactic structure and evolution. The most up-to-date abundances, distances (calibrated with Magellanic Cloud PNe), and other parameters have been employed, together with a novel homogeneous morphological classification, to characterize the different PN populations. We studied the {alpha}-element distribution within the Galactic disk, and found that the best selected disk population (i.e., excluding bulge and halo component), together with the most reliable PN distance scale yields to a radial oxygen gradient of {Delta}log(O/H)/{Delta}R_G_=-0.023+/-0.006dex/kpc for the whole disk sample, and of {Delta}log(O/H)/{Delta}R_G_=-0.035+/-0.024, -0.023+/-0.005, and -0.011+/-0.013dex/kpc, respectively for Type I, II, and III PNe, i.e., for high-, intermediate-, and low-mass progenitors. We also extend the Galactic metallicity gradient comparison by revisiting the open cluster [Fe/H] data from high resolution spectroscopy.
- ID:
- ivo://CDS.VizieR/J/MNRAS/410/2257
- Title:
- Galactic planetary nebulae at 24{mu}m
- Short Name:
- J/MNRAS/410/2257
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained 24{mu}m imaging, profiles and fluxes for 224 planetary nebulae (PNe) lying within the limits of the Galactic survey undertaken with the Multiband Imaging Photometer for Spitzer (MIPSGAL). It is noted that most of the PNe having extended 24{mu}m emission also possess circular morphologies, suggesting that the emission derives from cool grains located within the Asymptotic Giant Branch (AGB) mass-loss regimes. Certain of these haloes are found to have a surface brightness fall-off which may be consistent with secularly invariant mass loss within the PNe progenitors. By contrast, the 8.0{mu}m envelopes are detected out to smaller distances from the nuclei, and have a steeper rate of surface brightness fall-off; a phenomenon which may arise from changes in the excitation of polycyclic aromatic hydrocarbons (PAHs) within external photo-dissociation regimes (PDRs). Our 24{mu}m fluxes are compared to those in previously published studies, and this appears to indicate that many of the prior fluxes have been underestimated; a disparity may imply that previous aperture sizes were too small. We have also combined our 24{mu}m fluxes with measures at shorter mid-infrared (MIR) wavelengths, taken with the Infrared Array Camera (IRAC). These are used to investigate the positioning of PNe within the IRAC-MIPSGAL colour planes. The [8.0]-[24] and [5.8]-[24] colours are found to be large, and extend over the respective ranges 3.4-8.7mag, and 5.4-10.3mag; indices which are only explainable where a broad range of mechanisms contribute to the fluxes, including PAH bands, cool dust continua and a variety of ionic transitions. These and other components also affect the morphologies of the sources, and lead to wavelength-dependent changes in the widths of the profiles.
- ID:
- ivo://CDS.VizieR/J/ApJ/889/21
- Title:
- Galactic planetary nebulae with Gaia data
- Short Name:
- J/ApJ/889/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We matched the astrometry of central stars (CSs) of spectroscopically confirmed Galactic planetary nebulae (PNe) with DR2 Gaia parallaxes (p), finding 430 targets in common with p>0 and |{sigma}_p_/p|<1. A catalog of PNe whose CSs have DR2 Gaia parallaxes is presented in Table 1. We compared DR2 parallaxes with those in the literature, finding good correlation between the two samples. We used PNe parallaxes to calibrate the Galactic PN distance scale. Restricting the sample to objects with 20% parallax accuracy, we derive the distance scale log(R_pc_)=-(0.226+/-0.0155)xlog(S_H{beta}_)-(3.920+/-0.215), which represents a notable improvement with respect to previous ones. We found that the ionized mass versus optical thickness distance scale for Galactic PNe is not as constrained by the Gaia calibrators, but gives important insight into the nature of the PNe, and is essential to define the domain for our distance scale application. We placed the CSs whose distance has been determined directly by parallax on the HR diagram, and found that their location on the post-asymptotic-giant-branch (AGB) H-burning evolutionary tracks is typical for post-AGB stars.
