- ID:
- ivo://CDS.VizieR/J/ApJS/124/195
- Title:
- PN medium-resolution spectra
- Short Name:
- J/ApJS/124/195
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present medium-resolution (R~700) near-infrared (lambda=1-2.5m) spectra of a sample of planetary nebulae (PNe). A narrow slit was used which sampled discrete locations within the nebulae; observations were obtained at one or more positions in the 41 objects included in the survey. The PN spectra fall into one of four general categories: HI emission line-dominated PNe, HI and H_2_ emission line PNe, H_2_ emission line-dominated PNe, and continuum-dominated PNe. These categories correlate with morphological type, with the elliptical PNe falling into the first group, and the bipolar PNe primarily in the H_2_ and continuum emission groups. The categories also correlate with C/O ratio, with the O-rich objects generally falling into the first group and the C-rich objects in the other groups. Other spectral features were observed in all categories, such as continuum emission from the central star, C_2_, CN, and CO emission, and warm dust continuum emission toward the long wavelength end of the spectra. Molecular hydrogen was detected for the first time in four PNe. An excitation analysis was performed using the H_2_ line ratios for all of the PN spectra in the survey where a sufficient number of lines were observed.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/510/3102
- Title:
- PN Ou5 gri and RV curves
- Short Name:
- J/MNRAS/510/3102
- Date:
- 19 Jan 2022 08:33:22
- Publisher:
- CDS
- Description:
- We present a detailed study of the stellar and orbital parameters of the post-common envelope binary central star of the planetary nebula Ou5. Low-resolution spectra obtained during the primary eclipse - to our knowledge the first isolated spectra of the companion to a post-common-envelope planetary nebula central star - were compared to catalogue spectra, indicating that the companion star is a late K- or early M-type dwarf. Simultaneous modelling of multi-band photometry and time-resolved radial velocity measurements was then used to independently determine the parameters of both stars as well as the orbital period and inclination. The modelling indicates that the companion star is low mass (~0.25M_{sun}_) and has a radius significantly larger than would be expected for its mass. Furthermore, the effective temperature and surface gravity of nebular progenitor, as derived by the modelling, do not lie on single-star post-AGB evolutionary tracks, instead being more consistent with a post-RGB evolution. However, an accurate determination of the component masses is challenging. This is principally due to the uncertainty on the locus of the spectral lines generated by the irradiation of the companion's atmosphere by the hot primary (used to derive companion star's radial velocities), as well as the lack of radial velocities of the primary.
- ID:
- ivo://CDS.VizieR/J/MNRAS/414/860
- Title:
- PN towards Galactic bulge. [OIII] fluxes
- Short Name:
- J/MNRAS/414/860
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present [OIII]{lambda}5007 fluxes and angular diametres for 435 Planetary Nebulae (PNe) in the central 10{deg}x10{deg} region towards the Galactic bulge. Our sample is taken from the new discoveries of the MASH PN surveys as well as previously known PN. This sample accounts for 80 per cent of known PN in this region. Fluxes and diametres are measured from narrow-band imaging with the MOSAIC-II camera on the 4-m Blanco Telescope at the Cerro-Tololo Inter-American Observatory. This is the largest (~60deg^2^), uniform [OIII]{lambda}5007 survey of the inner Galactic bulge ever undertaken. 104 of the objects have measured [OIII]{lambda}5007, [OIII]{lambda}4959, H{alpha} or H{beta} fluxes from the literature, which we use to undertake a detailed comparison to demonstrate the integrity of our new fluxes. Our independent measurements are in excellent agreement with the very best literature sources over two orders of magnitude, while maintaining good consistency over five orders of magnitude. The excellent resolution and sensitivity of our data allows not only for a robust set of homogenous PN fluxes, but provides greater detail into their intricate, otherwise undetermined [OIII]{lambda}5007 morphologies. These new, extensive measurements significantly increase the sample of reliable [OIII]{lambda}5007 fluxes for Galactic bulge PN making it a valuable resource and a prelude to the construction of our new Galactic bulge PN luminosity function (Paper II, Kovacevic et al., in prep.).
- ID:
- ivo://CDS.VizieR/J/A+AS/76/317
- Title:
- Possible new planetary nebulae in IRAS PSC
- Short Name:
- J/A+AS/76/317
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A method for searching new possible planetary nebulae among the unidentified sources of the IRAS Point Source Catalog is described. Sources were selected according to their far infrared colours, proximity to galactic equator, and quality of the IRAS detection. A catalog of 388 new possible planetary nebulae is presented and the properties of the selected sample are discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A25
- Title:
- Post-AGB and CSPNe evolutionary models
- Short Name:
- J/A+A/588/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The post-asymptotic giant branch (AGB) phase is arguably one of the least understood phases of the evolution of low- and intermediate- mass stars. The two grids of models presently available are based on outdated micro- and macrophysics and do not agree with each other. Studies of the central stars of planetary nebulae (CSPNe) and post-AGB stars in different stellar populations point to significant discrepancies with the theoretical predictions of post-AGB models. We study the timescales of post-AGB and CSPNe in the context of our present understanding of the micro- and macrophysics of stars. We want to assess whether new post-AGB models, based on the latter improvements in TP-AGB modeling, can help us to understand the discrepancies between observation and theory and within theory itself. In addition, we aim to understand the impact of the previous AGB evolution for post-AGB phases. We computed a grid of post-AGB full evolutionary sequences that include all previous evolutionary stages from the zero age main sequence to the white dwarf phase. We computed models for initial masses between 0.8 and 4M_{sun}_ and for a wide range of initial metallicities (Z_0_= 0.02, 0.01, 0.001, 0.0001). This allowed us to provide post-AGB timescales and properties for H-burning post-AGB objects with masses in the relevant range for the formation of planetary nebulae (~0,5-0,8M_{sun}_). We included an updated treatment of the constitutive microphysics and included an updated description of the mixing processes and winds that play a key role during the thermal pulses (TP) on the AGB phase.
- ID:
- ivo://CDS.VizieR/J/A+A/648/A93
- Title:
- 4 post-AGB stars datacubes
- Short Name:
- J/A+A/648/A93
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- There is a class of binary post-AGB stars with a remarkable near-infrared excess that are surrounded by Keplerian or quasi-Keplerian disks and extended outflows composed of gas escaping from the disk. The Keplerian dynamics had been well identified in four cases, namely the Red Rectangle, AC Her, IW Car, and IRAS 08544-4431. In these objects, the mass of the outflow represents ~10% of the nebular mass, the disk being the dominant component of the nebula. We aim to study the presence of rotating disks in sources of the same class in which the outflow seems to be the dominant component. We present interferometric NOEMA maps of ^12^CO and ^13^CO J=2-1 in 89 Her and ^12^CO J=2-1 in AC Her, IRAS 19125+0343, and R Sct. Several properties of the nebula are obtained from the data and model fitting, including the structure, density, and temperature distributions, as well as the dynamics. We also discuss the uncertainties on the derived values. The presence of an expanding component in AC Her is doubtful, but thanks to new maps and models, we estimate an upper limit to the mass of this outflow of <=3x10^-5^M^{sun}_, that is, the mass of the outflow is <=5% of the total nebular mass. For 89 Her, we find a total nebular mass of 1.4x10^-2^M_{sun}_, of which ~50% comes from an hourglass-shaped extended outflow. In the case of IRAS 19125+0343, the nebular mass is 1.1x10^-2^M_{sun}_, where the outflow contributes ~70% of the total mass. The nebular mass of R Sct is 3.2x10^-2^M_{sun}_, of which ~75% corresponds to a very extended outflow that surrounds the disk. Our results for IRAS 19125+0343 and R Sct lead us to introduce a new subclass of binary post-AGB stars, for which the outflow is the dominant component of the nebula. Moreover, the outflow mass fraction found in AC Her is smaller than those found in other disk-dominated binary post-AGB stars. 89 Her would represent an intermediate case between both subclasses.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A17
- Title:
- Post-common-envelope PN and mol. mass
- Short Name:
- J/A+A/658/A17
- Date:
- 21 Mar 2022 09:39:31
- Publisher:
- CDS
- Description:
- Most planetary nebulae (PNe) show beautiful, axisymmetric morphologies despite their progenitor stars being essentially spherical. Close binarity is widely invoked to help eject an axisymmetric nebula, after a brief phase of engulfment of the secondary within the envelope of the Asymptotic Giant Branch (AGB) star, known as the common envelope (CE). The evolution of the AGB would thus be interrupted abruptly, its still quite massive envelope being rapidly ejected to form the PN, which a priori would be more massive than a PN coming from the same star, were it single. We aim at testing this hypothesis by investigating the ionised and molecular masses of a sample consisting of 21 post-CE PNe, roughly one fifth of the known total population of these objects, and comparing them to a large sample of 'regular' (i.e. not known to arise from close-binary systems) PNe. We have gathered data on the ionised and molecular content of our sample from the literature, and carried out molecular observations of several previously unobserved objects. We derive the ionised and molecular masses of the sample by means of a systematic approach, using tabulated, dereddened H-beta fluxes for finding the ionised mass, and ^12^CO J=2-1 and J=3-2 observations for estimating the molecular mass. There is a general lack of molecular content in post-CE PNe. Our observations only reveal molecule-rich gas around NGC 6778, distributed into a low-mass, expanding equatorial ring lying beyond the ionised broken ring previously observed in this nebula. The only two other objects showing molecular content (from the literature) are NGC 2346 and NGC 7293. Once we derive the ionised and molecular masses, we find that post-CE PNe arising from Single-Degenerate (SD) systems are just as massive, on average, as the 'regular' PNe sample, whereas post-CE PNe arising from Double-Degenerate (DD) systems are considerably more massive, and show substantially larger linear momenta and kinetic energy than SD systems and `regular' PNe. Reconstruction of the CE of four objects, for which a wealth of data on the nebulae and complete orbital parameters are available, further suggests that the mass of SD nebulae actually amounts to a very small fraction of the envelope of their progenitor stars. This leads to the uncomfortable question of where the rest of the envelope is and why we cannot detect it in the stars' vicinity, thus raising serious doubts on our understanding of these intriguing objects.
- ID:
- ivo://CDS.VizieR/J/A+A/479/155
- Title:
- Proper motions of Galactic Planetary Nebulae
- Short Name:
- J/A+A/479/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- More than 1500 Galactic planetary nebulae (PNe) are known but only a tiny fraction of them have measured proper motions. To date, the largest set of proper motion (PM) data for PNe is the one by Cudworth (1974AJ.....79.1384C), which includes 62 objects 25 of which have PM with significance better than 3{sigma}. With our new compilation of 234 PNe we enlarge - compared to Cudworth's 25 - by almost an order of magnitude the number of PNe and central stars (CSs) with reliably measured proper motion (i.e. with significance better than 3{sigma} in at least one component) and confirm some previous measurements. We have used all-sky astrometric catalogues available via the Vizier database to collect proper motion information for a sample of objects selected from the catalogue of PNe positions of Kerber et al. (2003, Cat. <J/A+A/408/1029>).
- ID:
- ivo://CDS.VizieR/J/A+A/593/A29
- Title:
- Properties of galactic PNe central stars
- Short Name:
- J/A+A/593/A29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained multi-wavelength observations of compact Galactic planetary nebulae (PNe) to probe post-asymptotic giant branch (AGB) evolution from the onset of nebular ejection. We analyze new observations from Hubble Space Telescope to derive the masses and evolutionary status of their central stars (CSs) in order to better understand the relationship between the CS properties and those of the surrounding nebulae. We work with HST/WFC3 images of 51 targets obtained in a snapshot survey (GO-11657). The high spatial resolution of HST allows us to resolve these compact PNe and distinguish the CS emission from that of their surrounding PNe. The targets were imaged through the filters F200LP, F350LP, and F814W from which we derive Johnson V and I magnitudes. We derive CS bolometric luminosities and effective temperatures using the Zanstra technique, from a combination of HST photometry and ground-based spectroscopic data. We present new unique photometric measurements of 50 CSs, and derived effective temperatures and luminosities for most of them.
- ID:
- ivo://CDS.VizieR/J/A+A/649/A164
- Title:
- Protoplanetary nebulae and young PN CO spectra
- Short Name:
- J/A+A/649/A164
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Fast outflows and their interaction with slow shells (generally known as the fossil circumstellar envelope of asymptotic giant branch stars) play an important role in the structure and kinematics of protoplanetary and planetary nebulae (pPNe, PNe). To properly study their effects within these objects, we also need to observe the intermediate-temperature gas, which is only detectable in the far-infrared (FIR) and submillimetre (submm) transitions. We study the physical conditions of the outflows presented in a number of pPNe and PNe, with a focus on their temperature and excitation states. We carried out Herschel/HIFI observations in the submm lines of 12CO in nine pPNe and nine PNe and complemented them with low-J CO spectra obtained with the IRAM 30m telescope and taken from the literature. The spectral resolution of HIFI allows us to identify and measure the different nebular components in the line profiles. The comparison with large velocity gradient (LVG) model predictions was used to estimate the physical conditions of the warm gas in the nebulae, such as excitation conditions, temperature, and density. We found high kinetic temperatures for the fast winds of pPNe, typically reaching between 75K and 200K. In contrast, the high-velocity gas in the sampled PNe is colder, with characteristic temperatures between 25K and 75K, and it is found in a lower excitation state. We interpret this correlation of the kinetic temperature and excitation state of fast outflows with the amount of time elapsed since their acceleration (probably driven by shocks) as a consequence of the cooling that occurred during the pPN phase.
