scholarly journals A Detailed Study of the Galactic Planetary Nebula G 258-15.7

1993 ◽  
Vol 155 ◽  
pp. 384-384
Author(s):  
P. Leisy ◽  
M. Dennefeld
Keyword(s):  
Planetary Nebula ◽  
Central Star ◽  
Striking Feature ◽  
Subsequent Paper ◽  
Type I ◽  
Significant Difference ◽  
Two Sides ◽  
Galactic Planetary Nebula

The galactic Planetary Nebula G 258-15.7 is a large, bright nebula well suited for a detailed study. Known since Wray (1966), its morphology presents several blobs and ansae, generally associated with type I nebulae, and could be described as “late-butterfly” type according to the classification by Balick (1989). The central star has been classified as hydrogen-deficient by Mendez et al. (1985). Spectroscopy of the two main blobs shows a clear overabundance in He and N, with a marginally significant difference between the two sides. The most striking feature is the jet-like structure appearing on the [OIII]/Halpha picture (Fig. 1), the “jets” being located within the main blobs seen on the monochromatic images. A detailed appraisal of all the data will be presented in a subsequent paper.

scholarly journals When nature tries to trick us

2018 ◽  
Vol 619 ◽  
pp. A84 ◽  
Author(s):  
Henri M. J. Boffin ◽  
David Jones ◽  
Roger Wesson ◽  
Yuri Beletsky ◽  
Brent Miszalski ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Binary Star ◽  
Central Star ◽  
Equal Mass ◽  
Type I ◽  
Eclipsing Binary ◽  
Common Envelope ◽  
Bright Object ◽  
F Stars ◽  
Central Stars

Bipolar planetary nebulae (PNe) are thought to result from binary star interactions and, indeed, tens of binary central stars of PNe have been found, in particular using photometric time-series that allow for the detection of post-common envelope systems. Using photometry at the NTT in La Silla we have studied the bright object close to the centre of PN M 3-2 and found it to be an eclipsing binary with an orbital period of 1.88 days. However, the components of the binary appear to be two A or F stars, of almost equal mass, and are therefore too cold to be the source of ionisation of the nebula. Using deep images of the central star obtained in good seeing conditions, we confirm a previous result that the central star is more likely much fainter, located 2″ away from the bright star. The eclipsing binary is thus a chance alignment on top of the planetary nebula. We also studied the nebular abundance and confirm it to be a Type I PN.

scholarly journals Twenty years of observations of PM 1-188: Its chemical abundances and extraordinary kinematics

2021 ◽  
Author(s):  
Miriam Peña ◽  
Liliana Hernández-Martínez ◽  
Francisco Ruiz-Escobedo
Keyword(s):  
Chemical Composition ◽  
Planetary Nebula ◽  
Central Star ◽  
Emission Lines ◽  
Type I ◽  
Chemical Abundances ◽  
Line Intensities ◽  
Physical Conditions ◽  
The Past ◽  
Spectrophotometric Data

Abstract The analysis of 20 years of spectrophotometric data of the double shell planetary nebula PM 1-188 is presented, aiming to determine the time evolution of the emission lines and the physical conditions of the nebula, as a consequence of the systematic fading of its [WC 10] central star whose brightness has declined by about 10 mag in the past 40 years. Our main results include that the [O iii], [O ii], [N ii] line intensities are increasing with time in the inner nebula as a consequence of an increase in electron temperature from 11 000 K in 2005 to more than 14 000 K in 2018, due to shocks. The intensity of the same lines are decreasing in the outer nebula, due to a decrease in temperature, from 13 000 K to 7000 K, in the same period. The chemical composition of the inner and outer shells was derived and they are similar. Both nebulae present subsolar O, S and Ar abundances, while they are He, N and Ne rich. For the outer nebula the values are 12+log He/H = 11.13 ± 0.05, 12+log O/H = 8.04 ± 0.04, 12+log N/H = 7.87 ± 0.06, 12+log S/H = 7.18 ± 0.10 and 12+log Ar = 5.33 ± 0.16. The O, S and Ar abundances are several times lower than the average values found in disc non-Type I PNe, and are reminiscent of some halo PNe. From high resolution spectra, an outflow in the N-S direction was found in the inner zone. Position-velocity diagrams show that the outflow expands at velocities in the −150 to 100 km s−1 range, and both shells have expansion velocities of about 40 km s−1.

scholarly journals Thermal and Density Structures and Elemental Abundances in the Bipolar PN Mz 3

2003 ◽  
Vol 209 ◽  
pp. 377-378
Author(s):  
Y. Zhang ◽  
X.-W. Liu
Keyword(s):  
Fine Structure ◽  
Planetary Nebula ◽  
Far Infrared ◽  
Central Star ◽  
Type I ◽  
Ionized Gas ◽  
Elemental Abundances ◽  
Angular Extent ◽  
Salient Features ◽  
Fine Structure Lines

Mz 3 is a young bipolar planetary nebula (PN) with lobes extending over ~ 50 arcsec on the sky. It consists of a bright core, two approximately spherical bipolar lobes and two outer large filamentary bipolar nebulae. The salient features of Mz 3 are more easily studied than other bipolar nebula because of its large angular extent. It is very bright in the far-infrared. There is an extended shell of warm dust surrounding the central star. And the bipolar lobes are filled with hot ionized gas. Cohen et al. (1978) found that Mz 3 is He-rich. Based on the LWS observations of the far-IR fine-structure lines, Liu et al. (2001) derived a high N/O ratio in Mz 3 and identified the bipolar nebula as a Type-I PN.

scholarly journals HST spectrophotometric data of the central star of the Planetary Nebula LMC-N66

1997 ◽  
Vol 180 ◽  
pp. 126-127
Author(s):  
M. Peña ◽  
W.-R. Hamann ◽  
L. Koesterke ◽  
J. Maza ◽  
R.H. Méndez ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Central Star ◽  
Short Time Scale ◽  
Type I ◽  
Ionization Degree ◽  
Filamentary Structure ◽  
High Ionization ◽  
Spectrophotometric Data ◽  
History Of ◽  
Short Time

N66 (WS 35, SMP 83) is a Type I (He-N rich) PN in the LMC with a high ionization degree. It shows a bipolar morphology with a filamentary structure (Dopita et al. 1993). Its central star has shown very impressive changes, in short time scale, that have been investigated. Here we describe the history of these changes:

scholarly journals 3D photoionization models: the bipolar PN IC 4406

1997 ◽  
Vol 180 ◽  
pp. 231-231
Author(s):  
R. Gruenwald ◽  
S. M. Viegas ◽  
D. Broguière
Keyword(s):  
Planetary Nebula ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Diffuse Radiation ◽  
Central Star ◽  
Type I ◽  
Chemical Abundances ◽  
Line Intensities ◽  
Physical Conditions ◽  
Self Consistent

A three-dimensional (3D) self-consistent photoionization code is developed in order to build more realistic models for asymmetrical and/or inhomogeneous photoionized nebulae. With these models the assumption of spherical or plane-parallel symmetry can be dropped and models with various geometries can be treated. The gaseous region is divided into numberous cubic cells, and the physical conditions in each cell are obtained taking into account the effect of the other cells in the optical depth and their contribution into the diffuse radiation. A model for IC 4406, which is a typical example of bipolar planetary nebula is presented. The model assumes a torus of dense material around the central star, as suggested in the literature. Its presence is confirmed by the model, in particular by the shape of the theoretical Hα + [NII] isophotal map. The chemical abundances required to explain the observed line intensities indicate that the chemical properties of this bipolar nebula are not characteristic of type I planetaries. A detailed paper will be published in Ap.J. (FAPESP, CNPq)

scholarly journals A barium central star binary in the Type I diamond ring planetary nebula Abell 70★

2011 ◽  
Vol 419 (1) ◽  
pp. 39-49 ◽  
Author(s):  
B. Miszalski ◽  
H. M. J. Boffin ◽  
D. J. Frew ◽  
A. Acker ◽  
J. Köppen ◽  
...  
Keyword(s):  
Planetary Nebula ◽  
Central Star ◽  
Type I ◽  
Star Binary ◽  
Diamond Ring

Rates of muscle protein synthesis in paraspinal muscles: Lateral disparity in children with idiopathic scoliosis

1988 ◽  
Vol 75 (1) ◽  
pp. 79-83 ◽  
Author(s):  
J. N. A. Gibson ◽  
M. J. McMaster ◽  
C. M. Scrimgeour ◽  
P. J. Stoward ◽  
M. J. Rennie
Keyword(s):  
Protein Synthesis ◽  
Idiopathic Scoliosis ◽  
Muscle Protein ◽  
Contractile Activity ◽  
Muscle Protein Synthesis ◽  
Fibre Diameter ◽  
Type I ◽  
Multifidus Muscle ◽  
Significant Difference ◽  
Two Sides

1. The rate of paraspinal (multifidus) muscle protein synthesis was measured bilaterally at the top, apex and bottom of the thoracic curve in nine children with an idiopathic scoliosis, using the stable-isotope-labelled amino acid l-[1-13C]leucine. 2. No significant difference was observed in rates of muscle protein synthesis between the two sides of the spine, at the levels of the first vertebrae in neutral alignment at the top and bottom of the curve. However, in every patient, at the apex of the spinal curve, synthesis was higher on the convexity than on the concavity (0.077 ±0.04 %/h convex, 0.052 ±0.02 %/h concave, means ±sd, P < 0.01). 3. Muscle RNA activity (μg of protein synthesized h−1 μg−1 of RNA) was lower at the curve apices on the concave than the convex side (0.019 ± 0.09 μg h−1 μg−1 convex apex, 0.016 ±0.06 μg h−1 μg−1 concave apex, P < 0.05). Activities were similar on the two sides at the top and bottom of the curve. 4. Differences in muscle histology between the two sides were also observed only at the apex, with a lower type I fibre diameter (50.9 ±8.5 μm convex, 38.3 ±2.4 μm concave, P < 0.05) and a lesser proportion of type I fibres (63 ± 12% convex, 49 ±9% concave, P < 0.05) on the concavity. 5. The results are consistent with effects on muscle protein turnover secondary to an increased muscle contractile activity on the curve convexity and functional immobilization of the muscle on the curve concavity.

scholarly journals Deep imaging of type I PN

1997 ◽  
Vol 180 ◽  
pp. 239-239
Author(s):  
C. T. Hua ◽  
M. A. Dopita
Keyword(s):  
Planetary Nebula ◽  
Total Mass ◽  
Quantitative Measurement ◽  
Central Star ◽  
Type I ◽  
Star System ◽  
Unknown Parameters ◽  
Ccd Imaging ◽  
Total Mass Loss ◽  
Deep Imaging

Progress in developing theories concerning the evolution of the central star and the surrounding planetary nebula requires a large, uniform set of data (monochromatic images, isophotes) which CCD imaging of PN can supply at present (Kaler, 1985; Balick 1987). One of the unknown parameters remains the mass budget of the (PN + central star) system. As a matter of fact, existing inventories of the measured ionised mass in PN reveal a shortfall as compared with theory. Nonetheless, since the major portion of the total mass loss occurs in the earlier ejection phases, a main objective was to detect the faint brightness peripheral nebular emissions and to provide quantitative measurement when possible of the global ionised mass.

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.

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