- ID:
- ivo://CDS.VizieR/J/A+A/538/A54
- Title:
- Spectroscopy of 12 [WC] planetary nebulae
- Short Name:
- J/A+A/538/A54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Planetary nebulae (PNe) around Wolf-Rayet [WR] central stars ([WR]PNe) constitute a particular photoionized nebula class that represents about 10% of the PNe with classified central stars. We analyse deep high-resolution spectrophotometric data of 12 [WR] PNe. This sample of [WR]PNe represents the most extensive analysed so far, at such high spectral resolution. We aim to select the optimal physical conditions in the nebulae to be used in ionic abundance calculations that will be presented in a forthcoming paper.
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- ID:
- ivo://CDS.VizieR/J/A+A/626/A92
- Title:
- Spitzer/IRS analysis of the 30-micron sources
- Short Name:
- J/A+A/626/A92
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis and comparison of the 30{mu}m dust features seen in the Spitzer Space Telescope spectra of 207 carbon-rich asymptotic giant branch (AGB) stars, post-AGB objects, and planetary nebulae (PNe) located in the Milky Way, the Magellanic Clouds (MCs), or the Sagittarius dwarf spheroidal galaxy (Sgr dSph), which are characterised by different average metallicities. We investigated whether the formation of the 30{mu}m feature carrier may be a function of the metallicity. Through this study we expect to better understand the late stages of stellar evolution of carbon-rich stars in these galaxies. Our analysis uses the "Manchester method" as a basis for estimating the temperature of dust for the carbon-rich AGB stars and the PNe in our sample. For post-AGB objects we changed the wavelength ranges used for temperature estimation, because of the presence of the 21{mu}m feature on the short wavelength edge of the 30{mu}m feature. We used a black-body function with a single temperature deduced from the Manchester method or its modification to approximate the continuum under the 30{mu}m feature. We find that the strength of the 30{mu}m feature increases until dust temperature drops below 400K. Below this temperature, the large loss of mass and probably the self-absorption effect reduces the strength of the feature. During the post-AGB phase, when the intense mass-loss has terminated, the optical depth of the circumstellar envelope is smaller, and the 30{um}m feature becomes visible again, showing variety of values for post-AGB objects and PNe, and being comparable with the strengths of AGB stars. In addition, the AGB stars and post-AGB objects show similar values of central wavelengths - usually between 28.5 and 29.5{mu}m. However, in case of PNe the shift of the central wavelength towards longer wavelengths is visible. The normalised median profiles for AGB stars look uniformly for various ranges of dust temperature, and different galaxies. We analysed the profiles of post-AGB objects and PNe only within one dust temperature range (below 200K), and they were also similar in different galaxies. In the spectra of 17 PNe and five post-AGB objects we found the broad 16-24{mu}m feature. Two objects among the PNe group are the new detections: SMP LMC 51, and SMP LMC 79, whereas in the case of post-AGBs the new detections are: IRAS 05370-7019, IRAS 05537-7015, and IRAS 21546+4721. In addition, in the spectra of nine PNe we found the new detections of 16-18{mu}m feature. We also find that the Galactic post-AGB object IRAS 11339-6004 has a 21{mu}m emission. Finally, we have produced online catalogues of photometric data and Spitzer IRS spectra for all objects that show the 30{mu}m feature. These resources are available online for use by the community. The most important conclusion of our work is the fact that the formation of the 30{mu}m feature is affected by metallicity. Specifically that, as opposed to more metal-poor samples of AGB stars in the MCs, the feature is seen at lower mass-loss rates, higher temperatures, and has seen to be more prominent in Galactic carbon stars. The averaged feature (profile) in the AGB, post-AGB objects, and PNe seems unaffected by metallicity at least between a fifth and solar metallicity, but in the case of PNe it is shifted to significantly longer wavelengths.
- ID:
- ivo://CDS.VizieR/J/AJ/135/726
- Title:
- Spitzer SAGE observations of LMC PNe
- Short Name:
- J/AJ/135/726
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present IRAC and MIPS images and photometry of a sample of previously known planetary nebulae (PNe) from the Surveying the Agents of a Galaxy's Evolution (SAGE) survey of the Large Magellanic Cloud (LMC) performed with the Spitzer Space Telescope. Of the 233 known PNe in the survey field, 185 objects were detected in at least two of the IRAC bands, and 161 detected in the MIPS 24um images. Color-color and color-magnitude diagrams are presented using several combinations of IRAC, MIPS, and Two Micron All Sky Survey magnitudes. The location of an individual PN in the color-color diagrams is seen to depend on the relative contributions of the spectral components which include molecular hydrogen, polycyclic aromatic hydrocarbons (PAHs), infrared forbidden line emission from the ionized gas, warm dust continuum, and emission directly from the central star. The sample of LMC PNe is compared to a number of Galactic PNe and found not to significantly differ in their position in color-color space. We also explore the potential value of IR PNe luminosity functions (LFs) in the LMC. IRAC LFs appear to follow the same functional form as the well-established [OIII] LFs although there are several PNe with observed IR magnitudes brighter than the cut-offs in these LFs.
- ID:
- ivo://CDS.VizieR/J/ApJ/622/294
- Title:
- STIS UV spectra of LMC planetary nebulae
- Short Name:
- J/ApJ/622/294
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We acquired spectra of 24 LMC planetary nebulae (PNs) in the 1150-3000{AA} range in order to determine carbon and other ionic abundances. The sample more than doubles the number of LMC PNs with high-quality UV spectra in this wavelength range and whose optical images are available in the Hubble Space Telescope archive. The Space Telescope Imaging Spectrograph was used with a very large aperture to obtain virtually slitless spectra; thus, the monochromatic images in the major nebula emission lines are also available. The analysis of the data shows extremely high quality spectra. This paper presents the emission lines identified and measured and the calculation of the ionic abundances of the emitting carbon and other ions, as well as total carbon abundance.
- ID:
- ivo://CDS.VizieR/V/84
- Title:
- Strasbourg-ESO Catalogue of Galactic Planetary Nebulae
- Short Name:
- V/84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The electronic version of the catalogue referenced above includes 1143 true and probable planetary nebulae (Table 1 of publication); 347 objects which status is still unclear were classified among the "possible" planetary nebulae (file pospn, Table 2 of publication); and 330 objects have been rejected (file notpn, Table 3 of publication). The designation system of the planetary nebulae of this catalogue follows the recommendations of IAU Commission 5 (Astronomical Nomenclature) with the structure: PN Glll.l+bb.b where PN means "Planetary Nebula", G stands for "Galactic Coordinates", and lll.l+bb.b stand for the galactic longitude and latitude respectively, truncated to one decimal place. The designations following this system appear in the columns labelled "PNG" in the tables described below, where the "PN G" prefix has been stripped. Data concerning the 1143 true and probable planetary nebulae (part II of the publication) have been grouped in a set of related tables described below, all sorted by the "PNG" column. Note that, unlike the printed volume, only the bibliographic references corresponding to data listed in the tables are provided here, in the "refs.dat" file. Copies of the complete catalogue, including the Finding Charts (Part I) can still be ordered at the ESO Information Service, Karl-Schwarzschildstr. 2, D-85748 Garching bei Muenchen, Germany, at a price of DM 135.
- ID:
- ivo://CDS.VizieR/J/AJ/153/140
- Title:
- The kinematics of the C II {lambda}6578 line in PNe
- Short Name:
- J/AJ/153/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic observations of the C II {lambda}6578 permitted line for 83 lines of sight in 76 planetary nebulae at high spectral resolution, most of them obtained with the Manchester Echelle Spectrograph on the 2.1 m telescope at the Observatorio Astronomico Nacional on the Sierra San Pedro Martir. We study the kinematics of the C II {lambda}6578 permitted line with respect to other permitted and collisionally excited lines. Statistically, we find that the kinematics of the C II {lambda}6578 line are not those expected if this line arises from the recombination of C^2+^ ions or the fluorescence of C^+^ ions in ionization equilibrium in a chemically homogeneous nebular plasma, but instead its kinematics are those appropriate for a volume more internal than expected. The planetary nebulae in this sample have well-defined morphology and are restricted to a limited range in H{alpha} line widths (no large values) compared to their counterparts in the Milky Way bulge; both these features could be interpreted as the result of young nebular shells, an inference that is also supported by nebular modeling. Concerning the long-standing discrepancy between chemical abundances inferred from permitted and collisionally excited emission lines in photoionized nebulae, our results imply that multiple plasma components occur commonly in planetary nebulae.
- ID:
- ivo://archive.stsci.edu/tues
- Title:
- Tubingen Echelle Spectrograph
- Short Name:
- TUES
- Date:
- 22 Jul 2020 21:31:05
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- The Tübingen Echelle (TUES) obtained moderate dispersion observations (R=13,000) using an echelle grating including orders 40 - 61 from 910 - 1410 Angstroms. The instrument was designed and built by the University of Tübingen (PI: M. Grewing) and flew as one of three spectrographs on the ORFEUS/SPAS-2 mission for 14 days in November/December 1996. The instrumental resolution was about 10,000 and the effective aperture peaks at 1.3 cm2 near 1100 Angstroms. Objects were observed in a 10 arcsec entrance aperture. The wavelength calibration was established by means of interstellar molecular hydrogen lines.
- ID:
- ivo://CDS.VizieR/J/MNRAS/454/2586
- Title:
- UWISH2 extended H2 emission line sources
- Short Name:
- J/MNRAS/454/2586
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the extended source catalogue for the UKIRT Wide Field Infrared Survey for H2 (UWISH2). The survey is unbiased along the inner Galactic Plane from l~357{deg} to l~65{deg} and |b|<=1.5{deg} and covers 209deg^2^. A further 42.0 and 35.5deg^2^ of high dust column density regions have been targeted in Cygnus and Auriga. We have identified 33200 individual extended H_2_ features. They have been classified to be associated with about 700 groups of jets and outflows, 284 individual (candidate) planetary nebulae, 30 supernova remnants and about 1300 photodissociation regions. We find a clear decline of star formation activity (traced by H_2_ emission from jets and photodissociation regions) with increasing distance from the Galactic Centre. About 60 percent of the detected candidate planetary nebulae have no known counterpart and 25 percent of all supernova remnants have detectable H_2_ emission associated with them.
- ID:
- ivo://CDS.VizieR/J/AJ/159/21
- Title:
- V and Rc light curves of medium-bright PPNe
- Short Name:
- J/AJ/159/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 10 years of new photometric monitoring of the light variability of five evolved stars with strong mid-infrared emission from surrounding dust. Three are known carbon-rich proto-planetary nebulae (PPNe) with F-G spectral types; the nature of the other two was previously unknown. For the three PPNe, we determine or refine the pulsation periods of IRAS04296+3429 (71 days), 06530-0213 (80 days), and 23304+6147 (84 days). A secondary period was found for each, with a period ratio P_2_/P_1_ of 0.9. The light variations are small, 0.1-0.2mag. These are similar to values found in other PPNe. The other two are found to be giant stars. IRAS09296+1159 pulsates with a period of only 47 days but reaches pulsational light variations of 0.5mag. Supplemental spectroscopy reveals the spectrum of a CH carbon star. IRAS08359-1644 is a G1III star that does not display pulsational variability; rather, it shows nonperiodic decreases of brightness of up to 0.5mag over this 10 year interval. These drops in brightness are reminiscent of the light curves of R Corona Borealis variables, but with much smaller decreases in brightness and are likely due to transient dust obscuration. Its spectral energy distribution is very similar to that of the unusual oxygen-rich giant star HDE233517, which possesses mid-infrared hydrocarbon emission features. These two non-PPNe turn out to be members of the rare group of giant stars with large mid-infrared excesses due to dust, objects which presumably have interesting evolutionary histories.
- ID:
- ivo://CDS.VizieR/J/ApJ/709/1042
- Title:
- Variability in C-rich proto-PNe.
- Short Name:
- J/ApJ/709/1042
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out long-term (14 years) V and R photometric monitoring of 12 carbon-rich proto-planetary nebulae. The light and color curves display variability in all of them. The light curves are complex and suggest multiple periods, changing periods, and/or changing amplitudes, which are attributed to pulsation. A dominant period has been determined for each and found to be in the range of ~150 days for the coolest (G8) to 35-40 days for the warmest (F3). A clear, linear inverse relationship has been found in the sample between the pulsation period and the effective temperature and also an inverse relationship between the amplitude of light variation and the effective temperature. These are consistent with the expectation for a pulsating post-asymptotic giant branch (post-AGB) star evolving toward higher temperature at constant luminosity. The published spectral energy distributions and mid-infrared images show these objects to have cool (200K), detached dust shells and published models imply that intensive mass loss ended 400-2000 years ago.
