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101. i light curve ans spectra of Hen2-11 central star
ID:
ivo://CDS.VizieR/J/A+A/562/A89
Title:
i light curve ans spectra of Hen2-11 central star
Short Name:
J/A+A/562/A89
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a detailed photometric study of the central star system of the planetary nebula Hen 2-11, selected for study because of its low-ionisation filaments and bipolar morphology - traits which have been strongly linked with central star binarity. Photometric monitoring with NTT-EFOSC2 reveals a highly irradiated, double-eclipsing, post-common-envelope system with a period of 0.609 d. Modelling of the lightcurve indicates that the nebular progenitor is extremely hot, while the secondary in the system is probably a K-type main sequence star. The chemical composition of the nebula is analysed, showing Hen 2-11 to be a medium-excitation non-Type I nebula. A simple photoionisation model is constructed determining abundance ratios of C/O and N/O which would be consistent with the common-envelope cutting short the AGB evolution of the nebular progenitor. The detection of a post-common-envelope binary system at the heart of Hen 2-11 further strengthens the link between binary progeny and the formation of axisymmetric planetary nebulae with patterns of low-ionisation filaments, clearly demonstrating their use as morphological indicators of central star binarity.
102. Infrared fluxes of HII regions and PNe
ID:
ivo://CDS.VizieR/J/A+A/537/A1
Title:
Infrared fluxes of HII regions and PNe
Short Name:
J/A+A/537/A1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We determine infrared color criteria for distinguishing between HII regions and planetary nebulae.
103. Infrared photometry of Galactic and MC PN
ID:
ivo://CDS.VizieR/J/MNRAS/396/1915
Title:
Infrared photometry of Galactic and MC PN
Short Name:
J/MNRAS/396/1915
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present mid-infrared (MIR) photometry for 367 Galactic disc, bulge and Large Magellanic Cloud (LMC) planetary nebulae (PNe), determined using data acquired with the Spitzer Space Telescope, and through the Legacy Programs GLIMPSE II (Galactic Legacy Infrared Mid-plane Survey Extraordinaire II) and SAGE (Surveying the Agents of the Galaxy's Evolution). This has permitted us to make a comparison between the luminosity functions of bulge and LMC PNe, and between the MIR colours of all three categories of source. It is determined that whilst the 3.6 {mu}m luminosity functions of the LMC and bulge sources are likely to be closely similar, the [3.6]-[5.8] and [5.8]-[8-0] indices of LMC nebulae are different from those of their disc and bulge counterparts. This may arise because of enhanced 6.2{mu}m polycyclic aromatic hydrocarbon emission within the LMC sources, and/or as a result of further, and more radical differences between the spectra of LMC and Galactic PNe. We also determine that the more evolved disc sources listed in the Macquarie/AAO/Strasbourg (MASH) catalogues of Parker et al. (2006MNRAS.373...79P) and Miszalski et al. (2008MNRAS.384..525M), Cat. V/127, have similar colours to those of the less evolved (and higher surface brightness) sources in the catalogue of Acker et al. (Cat. V/84), a result which appears at variance with previous studies of these sources.
104. Integrated spectrum of NGC 7027
ID:
ivo://CDS.VizieR/J/A+A/442/249
Title:
Integrated spectrum of NGC 7027
Short Name:
J/A+A/442/249
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present deep optical spectra of the archetypal young planetary nebula (PN) NGC 7027, covering a wavelength range from 3310 to 9160{AA}. The observations were carried out by uniformly scanning a long slit across the entire nebular surface, thus yielding average optical spectra for the whole nebula. A total of 937 emission features are detected. The extensive line list presented here should prove valuable for future spectroscopic analyses of emission line nebulae. The optical data, together with the archival IUE and ISO spectra, are used to probe the temperature and density structures and to determine the elemental abundances from lines produced by different excitation mechanisms.
105. Interacting planetary nebulae
ID:
ivo://CDS.VizieR/J/A+A/541/A98
Title:
Interacting planetary nebulae
Short Name:
J/A+A/541/A98
Date:
21 Oct 2021
Publisher:
CDS
Description:
We discuss the classification and orientation of planetary nebulae that interact with the interstellar medium throughout the Milky Way. A sample of 117 confirmed interacting planetary nebulae is used for this purpose. Our results indicate that the majority of interacting objects are located close to the Galactic plane, and ~77% of them are located inside the Galactic thin disk.
106. Internal proper motions in NGC2392
ID:
ivo://CDS.VizieR/J/ApJ/798/129
Title:
Internal proper motions in NGC2392
Short Name:
J/ApJ/798/129
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present measurements of internal proper motions at more than 500 positions of NGC 2392, the Eskimo Nebula, based on images acquired with WFPC2 on board the Hubble Space Telescope at two epochs separated by 7.695yr. Comparisons of the two observations clearly show the expansion of the nebula. We measured the amplitude and direction of the motion of local structures in the nebula by determining their relative shift during that interval. In order to assess the potential uncertainties in the determination of proper motions in this object, in general, the measurements were performed using two different methods, used previously in the literature. We compare the results from the two methods, and to perform the scientific analysis of the results we choose one, the cross-correlation method, because it is more reliable. We go on to perform a "criss-cross" mapping analysis on the proper motion vectors, which helps in the interpretation of the velocity pattern. By combining our results of the proper motions with radial velocity measurements obtained from high resolution spectroscopic observations, and employing an existing 3D model, we estimate the distance to the nebula to be 1.3kpc.
107. IPHAS new extended planetary nebulae release 1
ID:
ivo://CDS.VizieR/J/MNRAS/443/3388
Title:
IPHAS new extended planetary nebulae release 1
Short Name:
J/MNRAS/443/3388
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first results of our search for new, extended planetary nebulae (PNe) based on careful, systematic, visual scrutiny of the imaging data from the Isaac Newton Telescope Photometric Halpha Survey of the Northern Galactic plane (IPHAS). The newly uncovered PNe will help to improve the census of this important population of Galactic objects that serve as key windows into the late-stage evolution of low- to intermediate-mass stars. They will also facilitate study of the faint end of the ensemble Galactic PN luminosity function. The sensitivity and coverage of IPHAS allows PNe to be found in regions of greater extinction in the Galactic plane and/or those PNe in a more advanced evolutionary state and at larger distances compared to the general Galactic PN population. Using a set of newly revised optical diagnostic diagrams in combination with access to a powerful, new, multiwavelength imaging data base, we have identified 159 true, likely and possible PNe for this first catalogue release. The ability of IPHAS to unveil PNe at low Galactic latitudes and towards the Galactic Anticentre, compared to previous surveys, makes this survey an ideal tool to contribute to the improvement of our knowledge of the whole Galactic PN population.
108. IR colours of MASH planetary nebulae
ID:
ivo://CDS.VizieR/J/MNRAS/394/1875
Title:
IR colours of MASH planetary nebulae
Short Name:
J/MNRAS/394/1875
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have analysed the near-infrared (NIR) and far-infrared (FIR) colours of MASH I and MASH II (the Macquarie/AAO/Strasbourg surveys, Cat. <V/127>) planetary nebulae (PNe), using data deriving from the Two-Micron All-Sky Survey and Infrared Astronomical Satellite. We were able to identify ~5 per cent of the sources in the NIR, and a slightly larger fraction (~12 per cent) in the FIR. It is concluded that whilst the NIR colours of these nebulae are consistent with those of less evolved (and higher surface brightness) PNe, their FIR colours are markedly different. This disparity is likely to arise as a result of an evolution in dust temperatures, in their line emission characteristics, and in the relative contributions of the 8.6 and 11.3um polycyclic aromatic hydrocarbon emission features. A rump of~9 per cent of the detected sources have values log[F(25um)/F(60um)] which are lower than can be explained in terms of normal nebular evolution, however. If these are comparable in nature to the undetected PNe, then this would argue that ~1 in 10 of MASH I and II nebulae may represent galactic H ii regions, Stromgren spheres, symbiotic nebulae or other unrelated categories of source.
109. Iron Project. XLIV. Fe VI.
ID:
ivo://CDS.VizieR/J/A+AS/147/111
Title:
Iron Project. XLIV. Fe VI.
Short Name:
J/A+AS/147/111
Date:
21 Oct 2021
Publisher:
CDS
Description:
Relativistic atomic structure calculations for electric dipole (E1), electric quadrupole (E2) and magnetic dipole (M1) transition probabilities among the first 80 fine-structure levels of Fe VI, dominated by configurations 3d^3^, 3d^2^4s, and 3d^2^4p, are carried out using the Breit-Pauli version of the code SUPERSTRUCTURE. Experimental energies are used to improve the accuracy of these transition probabilities. Employing the 80-level collision-radiative (CR) model with these dipole and forbidden transition probabilities, and Iron Project R-matrix collisional data, we present a number of [Fe VI] line ratios applicable to spectral diagnostics of photoionized H II regions. It is shown that continuum fluorescent excitation needs to be considered in CR models in order to interpret the observed line ratios of optical [Fe VI] lines in planetary nebulae NGC 6741, IC 351, and NGC 7662. The analysis leads to parametrization of line ratios as function of, and as constraints on, the electron density and temperature, as well as the effective radiation temperature of the central source and a geometrical dilution factor. The spectral diagnostics may also help ascertain observational uncertainties. The method may be generally applicable to other objects with intensive background radiation fields, such as novae and active galactic nuclei. The extensive new Iron Project radiative and collisional calculations enable a consistent analysis of many line ratios for the complex iron ions.
110. JHKLM photometry of eight planetary nebulae
ID:
ivo://CDS.VizieR/J/PAZh/33/657
Title:
JHKLM photometry of eight planetary nebulae
Short Name:
J/PAZh/33/657
Date:
21 Oct 2021
Publisher:
CDS
Description:
We discuss the infrared (IR) (1.25-5microns) photometry of eight planetary nebulae performed in 1999-2006. For all of the nebulae under study, we have firmly established IR brightness and color variations on time scales shorter than one year and up to 6-8 years. The greatest IR brightness variations were observed in IC 2149, IC 4997, and NGC 7662. Their J magnitudes varied within 0.2-0.25mag. In the remaining objects, the J magnitude variations did not exceed 0.15mag. All of the planetary nebulae under study exhibited IR color variations. Based on the IR photometry, we have classified the central regions of planetary nebula NGC 1514 and of the northern part of NGC 7635 seen through a 12" aperture as B(3-7) main-sequence star (NGC 1514) and O9.5 upper-main-sequence star (NGC 7635). The nebulae IC 4997 and NGC 7027 exhibited an excess emission (with respect to the emission from a hot source) at wavelength more than 2.5micron.