scholarly journals Dynamics of the M31 Planetary Nebula System

1995 ◽  
Vol 10 ◽  
pp. 473-474
Author(s):  
Xiaohui Hui
Keyword(s):  
Planetary Nebula ◽  
Globular Clusters ◽  
Planetary Nebulae ◽  
Radial Velocities ◽  
Stellar Disk ◽  
Dynamical Transition ◽  
Projected Area ◽  
Large Dataset ◽  
Dynamical Study ◽  
M 31

AbstractWe made a spatially complete and kinematically unbiased survey of M 31 for planetary nebulae (PNs). The survey covers a projected area of 20 by 40 kpc centered on M 31. Subsequently, we measured the radial velocities of over 800 PNs using the Hydra multi-object spectrograph on the KPNO 4-m telescope. With this large dataset, a detailed dynamical study of the stellar disk, bulge and halo populations in M 31 is currently underway. We are focusing on the dynamical transition between the disk, bulge and halo, and a comparison between the kinematics of the PNs and globular clusters.

scholarly journals On the triple-star origin of the planetary nebula Sh 2-71

2019 ◽  
Vol 489 (2) ◽  
pp. 2195-2203 ◽  
Author(s):  
David Jones ◽  
Ondřej Pejcha ◽  
Romano L M Corradi
Keyword(s):  
Mass Loss ◽  
Triple System ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Central Star ◽  
Radial Velocities ◽  
Proper Motions ◽  
Numerical Integrations ◽  
Open Questions ◽  
Triple Star

ABSTRACT Recent studies have indicated that triple-star systems may play a role in the formation of an appreciable number of planetary nebulae, however, only one triple central star is known to date (and that system is likely too wide to have had much influence on the evolution of its component stars). Here, we consider the possibility that Sh 2-71 was formed by a triple system that has since broken apart. We present the discovery of two regions of emission, seemingly aligned with the proposed tertiary orbit (i.e. in line with the axis formed by the two candidate central star systems previously considered in the literature). We also perform a few simple tests of the plausibility of the triple hypothesis based on the observed properties (coordinates, radial velocities, distances, and proper motions) of the stars observed close to the projected centre of the nebula, adding further support through numerical integrations of binary orbits responding to mass loss. Although a number of open questions remain, we conclude that Sh 2-71 is currently one of the best candidates for planetary nebula formation influenced by triple-star interactions.

scholarly journals JD1-The Planetary Nebulae and the Dynamics of NGC 1399

2009 ◽  
Vol 5 (H15) ◽  
pp. 66-66
Author(s):  
Emily McNeil ◽  
Magda Arnaboldi ◽  
Ortwin Gerhard ◽  
Kenneth Freeman ◽  
Payel Das ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Globular Clusters ◽  
Planetary Nebulae ◽  
Spectroscopy Technique ◽  
Dynamical Models ◽  
Kinematic Data

Dynamical models of galaxies are limited by the paucity of kinematic data at large radii. Beyond the feasible limit of integrated-light spectroscopy, we rely on discrete tracers such as planetary nebulae and globular clusters. We describe a large (~200) sample of planetary nebula (PN) velocities in the outer regions of the cD elliptical NGC 1399. These data were obtained with a counter-dispersed slitless-spectroscopy technique which traces the kinematics to about 60 kpc (McNeil et al., 2009).

scholarly journals A study of extragalactic planetary nebulae populations based on spectroscopy. I. Data compilation and first findings

2020 ◽  
Vol 498 (4) ◽  
pp. 5367-5385
Author(s):  
G Delgado-Inglada ◽  
J García-Rojas ◽  
G Stasińska ◽  
J S Rechy-García
Keyword(s):  
Strong Correlation ◽  
Planetary Nebula ◽  
Spectroscopic Data ◽  
Luminosity Function ◽  
Planetary Nebulae ◽  
The Other ◽  
H Ii Regions ◽  
Electron Densities ◽  
Data Compilation ◽  
M 31

ABSTRACT We compile published spectroscopic data and [O iii] magnitudes of almost 500 extragalactic planetary nebulae (PNe) in 13 galaxies of various masses and morphological types. This is the first paper of a series that aims to analyse the PN populations and their progenitors in these galaxies. Although the samples are not complete or homogeneous, we obtain some first findings through the comparison of a few intensity line ratios and nebular parameters. We find that the ionized masses and the luminosities in H β, LH β, of around 30 objects previously identified as PNe indicate that they are most likely compact H ii regions. We find an anticorrelation between the electron densities and the ionized masses in M 31, M 33, and NGC 300 that suggests that most of the PNe observed in these galaxies are probably ionization bounded. This trend is absent in LMC and SMC suggesting that many of their PNe are density bounded. The He ii λ4686/H β values found in many PNe in LMC and some in M 33 and SMC are higher than in the other galaxies. Photoionization models predict that these high values can only be reached in density bounded PNe. We also find that the brightest PNe in the sample are not necessarily the youngest since there is no correlation between electron densities and the H β luminosities. The strong correlation found between LH β and $L_{[\rm {O}\, \small {III}] }$ implies that the so far not understood cut-off of the planetary nebula luminosity function (PNLF) based on [O iii] magnitudes can be investigated using LH β, a parameter much easier to study.

scholarly journals A dedicated camera for extragalactic Planetary Nebulae: The Planetary Nebula Spectrograph

1997 ◽  
Vol 180 ◽  
pp. 493-494 ◽  
Author(s):  
N.G. Douglas ◽  
K. Taylor ◽  
K. C. Freeman ◽  
T. S. Axelrod
Keyword(s):  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Dynamical Behaviour ◽  
Virgo Cluster ◽  
Radial Velocities ◽  
External Galaxies

Photometry in [OIII] emission of Planetary Nebulae in external galaxies can be used to determine distances as great as that of the Virgo cluster and beyond, as forcefully argued elsewhere during this conference (G.H. Jacoby, invited talk). In addition, measurement of the radial velocities of the PN allows dynamical behaviour to be probed to much greater distance from the galaxian centre than integrated light techniques (e.g. Arnaboldi 1994).

scholarly journals The Planetary Nebula Luminosity Function (PNLF) of Our Galaxy Compared to those of other Galaxies

1995 ◽  
Vol 10 ◽  
pp. 498-500
Author(s):  
R. H. Méndez
Keyword(s):  
Planetary Nebula ◽  
Luminosity Function ◽  
Planetary Nebulae ◽  
Solar Neighborhood ◽  
Wise Decision ◽  
M 31 ◽  
The Individual

Nowadays it is possible to detect planetary nebulae, and measure their [O III] λ5007 fluxes, in many galaxies. Given this information it is relatively straightforward to build the [O III] λ5007 PNLF for any galaxy, because we can always assume all its PNs to be essentially at the same distance from us.Of course the situation is much more difficult for PNs in the solar neighborhood. We have two problems here: (1) the individual PN distances are poorly known, except for ∼ 25 objects; (2) in the literature there is no agreement on which are the 25 PNs with reliable distances. Clearly it was a wise decision to calibrate the PNLF method of extragalactic distance determinations using the distance to M 31 (Ciardullo et al. 1989, Jacoby et al. 1992). In these short notes I review if it may be possible to build a PNLF for our Galaxy (the answer is: yes, probably more than one) and discuss if it would be worth the trouble (the answer is: yes, it would) and what can be done to achieve that elusive goal.

scholarly journals Planetary Nebulae in M31: Abundances, and comparison with bright Planetary Nebulae in the LMC

1997 ◽  
Vol 180 ◽  
pp. 475-476
Author(s):  
M. G. Richer ◽  
G. Stasińska ◽  
M. L. McCall
Keyword(s):  
Planetary Nebula ◽  
Luminosity Function ◽  
Large Population ◽  
Wavelength Region ◽  
Planetary Nebulae ◽  
Surprising Result ◽  
Population Synthesis ◽  
Abundance Distribution ◽  
Wide Range ◽  
The Mean

We have obtained spectra of 28 planetary nebulae in the bulge of M31 using the MOS spectrograph at the Canada-France-Hawaii Telescope. Typically, we observed the [O II] λ3727 to He I λ5876 wavelength region at a resolution of approximately 1.6 å/pixel. For 19 of the 21 planetary nebulae whose [OIII]λ5007 luminosities are within 1 mag of the peak of the planetary nebula luminosity function, our oxygen abundances are based upon a measured [OIII]λ4363 intensity, so they are based upon a measured electron temperature. The oxygen abundances cover a wide range, 7.85 dex < 12 + log(O/H) < 9.09 dex, but the mean abundance is surprisingly low, 12 + log(O/H)–8.64 ± 0.32 dex, i.e., roughly half the solar value (Anders & Grevesse 1989). The distribution of oxygen abundances is shown in Figure 1, where the ordinate indicates the number of planetary nebulae with abundances within ±0.1 dex of any point on the x-axis. The dashed line indicates the mean abundance, and the dotted lines indicate the ±1 σ points. The shape of this abundance distribution seems to indicate that the bulge of M31 does not contain a large population of bright, oxygen-rich planetary nebulae. This is a surprising result, for various population synthesis studies (e.g., Bica et al. 1990) have found a mean stellar metallicity approximately 0.2 dex above solar. This 0.5 dex discrepancy leads one to question whether the mean stellar metallicity is as high as the population synthesis results indicate or if such metal-rich stars produce bright planetary nebulae at all. This could be a clue concerning the mechanism responsible for the variation in the number of bright planetary nebulae observed per unit luminosity in different galaxies (e.g., Hui et al. 1993).

scholarly journals Planetary Nebula Evolution Traced by Distance-Independent Parameters

1993 ◽  
Vol 155 ◽  
pp. 480-480
Author(s):  
C.Y. Zhang ◽  
S. Kwok
Keyword(s):  
Physical Properties ◽  
Mass Distribution ◽  
Planetary Nebula ◽  
Strong Support ◽  
Planetary Nebulae ◽  
Central Star ◽  
Evolution Model ◽  
The Core ◽  
Independent Parameters ◽  
Central Stars

Making use of the results from recent infrared and radio surveys of planetary nebulae, we have selected 431 nebulae to form a sample where a number of distance-independent parameters (e.g., Tb, Td, I60μm and IRE) can be constructed. In addition, we also made use of other distance-independent parameters ne and T∗ where recent measurements are available. We have investigated the relationships among these parameters in the context of a coupled evolution model of the nebula and the central star. We find that most of the observed data in fact lie within the area covered by the model tracks, therefore lending strong support to the correctness of the model. Most interestingly, we find that the evolutionary tracks for nebulae with central stars of different core masses can be separated in a Tb-T∗ plane. This implies that the core masses and ages of the central stars can be determined completely independent of distance assumptions. The core masses and ages have been obtained for 302 central stars with previously determined central-star temperatures. We find that the mass distribution of the central stars strongly peaks at 0.6 M⊙, with 66% of the sample having masses <0.64 MM⊙. The luminosities of the central stars are then derived from their positions in the HR diagram according to their core masses and central star temperatures. If this method of mass (and luminosity) determination turns out to be accurate, we can bypass the extremely unreliable estimates for distances, and will be able to derive other physical properties of planetary nebulae.

scholarly journals The Remarkable Evolution of the Post-Agb Star FG SGE

1998 ◽  
Vol 11 (1) ◽  
pp. 363-363
Author(s):  
Johanna Jurcsik ◽  
Benjamin Montesinos
Keyword(s):  
Time Scales ◽  
Effective Temperature ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Central Star ◽  
Evolutionary Models ◽  
Single Star ◽  
Line Intensities ◽  
Evolutionary Changes ◽  
Evolutionary Studies

FG Sagittae is one of the most important key objects of post-AGB stellar evolutionary studies. As a consequence of a final helium shell flash, this unique variable has shown real evolutionary changes on human time scales during this century. The observational history was reviewed in comparison with predictions from evolutionary models. The central star of the old planetary nebula (Hel-5) evolved from left to right in the HR diagram, going in just hundred years from the hot region of exciting sources of planetary nebulae to the cool red supergiant domain just before our eyes becoming a newly-born post-AGB star. The effective temperature of the star was around 50,000 K at the beginning of this century, and the last estimates in the late 1980s give 5,000-6,500 K. Recent spectroscopic observations obtained by Ingemar Lundström show definite changes in the nebular line intensities. This fact undoubtedly rules out the possibility that, instead of FG Sge, a hidden hot object would be the true central star of the nebula. Consequently, the observed evolutionary changes are connected with the evolution of a single star.

scholarly journals Age estimations of M 31 globular clusters from their spectral energy distributions

2006 ◽  
Vol 449 (1) ◽  
pp. 143-149 ◽  
Author(s):  
J. Ma ◽  
X. Zhou ◽  
D. Burstein ◽  
Y. Yang ◽  
Z. Fan ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Spectral Energy ◽  
Spectral Energy Distributions ◽  
Energy Distributions ◽  
M 31
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