- ID:
- ivo://CDS.VizieR/J/A+A/518/A44
- Title:
- NGC 1399 planetary nebula velocities
- Short Name:
- J/A+A/518/A44
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a counter-dispersed slitless spectroscopy technique, we detect and measure the line-of-sight velocities of 187 planetary nebulae (PNe) around one of the nearest cD galaxies, NGC 1399, with FORS1 on the VLT. We describe the method for identifying and classifying the emission-line sources and the procedure for computing their J2000 coordinates and velocities. The number of PN detections and the errors in the velocity measurements (37km/s) indicate that this technique is comparable to other methods. **************************************************************************** * * * The PN line-of-sight velocities will be published with a * * subsequent paper that also includes dynamical models of the system. * * * ****************************************************************************
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162. NGC 5128 PN. III.
- ID:
- ivo://CDS.VizieR/J/ApJ/449/592
- Title:
- NGC 5128 PN. III.
- Short Name:
- J/ApJ/449/592
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the halo dynamics and mass distributions of the nearby giant elliptical galaxy NGC 5128 using planetary nebulae (PNs) as test particles. Radial velocities of 433 PNs were obtained with multifiber spectrographs on both the Anglo-Australian Telescope (AAT) and the Cerro Tololo Inter-American Observatory (CTIO) 4m telescope. The velocities were measured from the [O III]{lambda}5007 emission line with a typical 1{sigma} error of +/-4km/s and +/-30km/s for the AAT and the CTIO data, respectively. These PNs cover the entire galaxy to a radius of 10kpc and extend along the photometric major axis out to 20kpc. The PN velocity field shows the distinctive characteristics of a triaxial potential: the galaxy's rotation axis is offset from its photometric minor axis by 39+/-10deg; the rotation axis and the line of maximum rotation are likely not orthogonal. We also find that the ordered motions of the stars become more important with increasing radius compared to their random motions. The rotation reaches approximately 100km/s and 50km/s along the photometric major and minor axes, giving a local V/{sigma} ratio of about 1.0 and 0.5, respectively. The aximuthal variation of the velocity dispersion appears to be modulated by rotation, i.e., it reaches a maximum where the largest rotation is observed and drops to a minimum at zero rotation. The amplitude of this modulation is about 20km/s, compared to a mean dispersion velocity of 110km/s. The kinematics of the globular clusters depend on the metallicity. Taking [Fe/H]=-1.0 as the dividing point, the metal-poor clusters do not show any significant rotation. However the metal-rich clusters show both major and minor axis rotation, and the amplitudes of the rotation are similar to that of the PNs. The stellar velocity dispersion measured from absorption-line spectra together with an H{alpha} rotation curve of the dust lane suggest that the stellar orbits are isotropic and the mass-to-light ratio (M/L_B_) is 3.9 in the central region of the galaxy. By applying the isotropic Jeans equation to the observed PN major axis rotation and velocity dispersion, we show that the M/L_B_ increases with radius, suggesting the presence of dark matter in the halo. Within a 25kpc radius, the total mass of the galaxy is 3.1x10^11^M_{sun}_ and M/L_B_=10. The rotation velocity of the recently detected H I ring at a radius of 15kpc confirms our mass model. The misalignment of the rotation axis relative to the photometric minor axis, combined with the knowledge of the dust lane orientation, allows us to uniquely determine the observer's viewing direction. The true shape of the galaxy is nearly spherical yet sufficiently triaxial to impose a distinctive gravitational signature on the kinematics.
- 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.
- 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.
