scholarly journals The morpho-kinematical structure and chemical abundances of the complex planetary nebula NGC 1514

2021 ◽  
Author(s):  
A Aller ◽  
R Vázquez ◽  
L Olguín ◽  
L F Miranda ◽  
M Ressler
Keyword(s):  
High Resolution ◽  
Planetary Nebula ◽  
Current Data ◽  
Time Sequence ◽  
Emission Lines ◽  
Physical Parameters ◽  
Chemical Abundances ◽  
Mid Infrared ◽  
Kinematical Analysis ◽  
Multiple Structures

Abstract We present high-resolution, long-slit optical spectra and images of the planetary nebula NGC 1514. The position velocity maps of the [O iii] emission line reveal complex kinematics with multiple structures. A morpho-kinematical analysis suggests an inner shell, originally spherical and now distorted by several bubbles, and an attached outer shell. The two well-defined, mid-infrared rings of NGC 1514 are not detected in our high-resolution, long-slit spectra, which prevented us from doing a kinematical analysis of them. Based exclusively on their morphology, we propose a barrel-like structure to explain the rings. Several ejection processes have been possibly involved in the formation of the nebula although a time sequence is difficult to establish with the current data. We also analyse intermediate-resolution, long-slit spectra with the goal of studying the physical parameters and chemical abundances of NGC 1514. The nebular spectra reveal a moderate-excitation nebula with weak emission lines of [Ar iii], [Ne iii], He i and He ii. No [N ii] neither other low-excitation emission lines are detected. We found an electron temperature around 14000 K in the gas and an electron density in the range of 2000 and 4000 cm−3.

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 Small Galactic Nebulae

1987 ◽  
Vol 115 ◽  
pp. 191-192
Author(s):  
Yervant Terzian ◽  
Kenneth C. Turner
Keyword(s):  
High Resolution ◽  
Planetary Nebula ◽  
Physical Parameters ◽  
H Ii Regions ◽  
Radio Observations ◽  
Cluster Emission ◽  
Active Star ◽  
Star Forming ◽  
Cometary Nebula ◽  
Significant Flux

We have performed high resolution VLA radio observations for several small H II regions, including the cluster emission nebulae S258, S255, S257, and S256. The region (PP56) between S255 and S257 at λ2 cm reveals significant flux structure close to OH, H2O and infrared emitting sources as shown in Figure 1. The flux densities and positions are indicated in Table 1. Observations of the cometary nebula PP59 (S269) also reveal similar characteristics as shown in Figure 2. These regions are considered to be active star-forming clouds. The cometary nebula PP40 was also observed and we note that its physical parameters are very similar to those of a typical planetary nebula.

scholarly journals Morphological and kinematical analysis of the planetary nebula Hu 1-2 and its irradiated bow-shocks

2011 ◽  
Vol 7 (S283) ◽  
pp. 440-441
Author(s):  
Luis F. Miranda ◽  
Mónica Blanco ◽  
Martín A. Guerrero ◽  
Angels Riera
Keyword(s):  
High Resolution ◽  
High Velocity ◽  
Planetary Nebula ◽  
Narrow Band ◽  
Central Star ◽  
Kinematical Analysis ◽  
Near Ir ◽  
Bow Shocks

AbstractWe present narrow-band optical and near-IR images, and high-resolution long-slit spectra of the planetary nebula Hu 1-2 that allow us to make a detailed description of its unusual morphology and internal kinematics. The data also reveal that the ansae of Hu 1-2 probably represent bow-shocks associated to high velocity outflows that are irradiated from the central star.

scholarly journals High-resolution spectroscopy of the high-velocity hot post-AGB star IRAS 18379–1707 (LS 5112)

2019 ◽  
Vol 491 (4) ◽  
pp. 4829-4842 ◽  
Author(s):  
N P Ikonnikova ◽  
M Parthasarathy ◽  
A V Dodin ◽  
S Hubrig ◽  
G Sarkar
Keyword(s):  
High Resolution ◽  
Model Atmosphere ◽  
Emission Lines ◽  
High Resolution Spectroscopy ◽  
Atmospheric Parameters ◽  
Optical Counterpart ◽  
Chemical Abundances ◽  
Balmer Lines ◽  
Cno Abundances ◽  
First Time

ABSTRACT The high-resolution ($R\sim 48\, 000$) optical spectrum of the B-type supergiant LS 5112, identified as the optical counterpart of the post-AGB candidate IRAS 18379–1707 is analysed. We report the detailed identifications of the observed absorption and emission features in the wavelength range 3700–9200 Å for the first time. The absorption line spectrum has been analysed using non-LTE model atmosphere techniques to determine stellar atmospheric parameters and chemical composition. We estimate Teff = 18 000 ± 1000 K, log g = 2.25 ± 0.08, ξt = 10 ± 4 km s−1, and vsin i = 37 ± 6 km s−1, and the derived abundances indicate a metal-deficient ([M/H] ≈ −0.6) post-AGB star. Chemical abundances of eight different elements were obtained. The estimates of the CNO abundances in IRAS 18379–1707 indicate that these elements are overabundant with [(C + N + O)/S] = + 0.5 ± 0.2 suggesting that the products of helium burning have been brought to the surface as a result of third dredge-up on the AGB. From the absorption lines, we derived heliocentric radial velocity of Vr = −124.0 ± 0.4 km s−1. We have identified permitted emission lines of O i, N i, Na i, S ii, Si ii, C ii, Mg ii, and Fe iii. The nebula forbidden lines of [N i], [O i], [Fe ii], [N ii], [S ii], [Ni ii], and [Cr ii] have also been identified. The Balmer lines H α, H β, and H γ show P-Cygni behaviour clearly indicating post-AGB mass-loss process in the object with the wind velocity up to 170 km s−1.

scholarly journals High-resolution spectroscopic study of the planetary nebula Abell 78

1999 ◽  
Vol 193 ◽  
pp. 374-375
Author(s):  
Selene Medina ◽  
Miriam Peña
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Spectroscopic Study ◽  
Spectral Resolution ◽  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Central Star ◽  
Heavy Elements ◽  
Physical Parameters ◽  
Processed Material

High resolution optical spectra of the planetary nebula Abell 78 were gathered, covering the wavelength ranges 3500–6600 Å and 3358–7361 Å, with a spectral resolution of ∼0.1 Å. Two different regions of Abell 78 are analyzed: the strongest knot near the central star which is thought to be a mass-loaded wind from the central star, and the outer, hydrogen-rich envelope. Physical parameters and chemical composition of both regions are estimated. The inner knot appears to be cooler and denser than the hydrogen-rich envelope. The chemical composition of the inner knot shows that there is almost no hydrogen near the central star and the emission is dominated by helium and processed material which has been dredged-up from the inner layers of the star. The outer, hydrogen-rich envelope appears to be deficient in heavy elements, mainly in oxygen, compared to the average abundances that are found among galactic planetary nebulae.

scholarly journals Planetary nebulae and the chemical evolution of the galactic bulge: New abundances of older objects

2011 ◽  
Vol 7 (S283) ◽  
pp. 326-327 ◽  
Author(s):  
Oscar Cavichia ◽  
Roberto D. D. Costa ◽  
Mercedes Mollá ◽  
Walter J. Maciel
Keyword(s):  
Chemical Evolution ◽  
Planetary Nebula ◽  
Luminosity Function ◽  
Planetary Nebulae ◽  
Physical Parameters ◽  
Galactic Bulge ◽  
Chemical Abundances ◽  
The Galaxy ◽  
Low Dispersion ◽  
Chemical Evolution Model

AbstractIn view of their nature, planetary nebulae have very short lifetimes, and the chemical abundances derived so far have a natural bias favoring younger objects. In this work, we report physical parameters and abundances for a sample of old PNe located in the galactic bulge, based on low dispersion spectroscopy secured at the SOAR telescope using the Goodman Spectrograph. The new data allow us to extend our database including older, weaker objects that are at the faint end of the planetary nebula luminosity function (PNLF). The results show that the abundances of our sample are lower than those from our previous work. Additionally, the average abundances of the galactic bulge do not follow the observed trend of the radial abundance gradient in the disk. These results are in agreement with a chemical evolution model for the Galaxy recently developed by our group.

scholarly journals Evidence of Expansion in the Central Region of NGC 2346

1989 ◽  
Vol 131 ◽  
pp. 187-187
Author(s):  
D.P.K. Banerjee ◽  
B. G. Anandarao ◽  
J. N. Desai ◽  
S. K. Jain ◽  
D.C.V. Mallik
Keyword(s):  
High Resolution ◽  
Spectral Range ◽  
Central Region ◽  
Planetary Nebula ◽  
Signal To Noise Ratio ◽  
Emission Lines ◽  
Expansion Velocity ◽  
Signal To Noise ◽  
Central Spot ◽  
Fabry Perot

We present observations of the bipolar planetary nebula NGC 2346 carried out with the 1-m telescope at the Vainu Bappu Observatory in Kavalur, India using (1) a high resolution piezo-electric scanned Fabry-Pérot Spectrometer (with a velocity resolution of 10 km s−1) for line studies in the 6000 A - 7000 A spectral range and (2) a pressure scanned Fabry-Pérot spectrometer (with a velocity-resolution of 5 km s−1) in the green region. The nebula was observed in the H I 6563 A and [N II] 6583 A emission lines using a 15″ aperture and in the [O III] 5007 A line using an 8″ aperture centered on the bright central spot. A number of scans in each of these lines were co-added to improve the signal-to-noise ratio. The [O III] profile shows a well defined split between the blue and the red component, typical of an expanding shell. The [N II] profile does not show a well resolved split, although a pronounced suggestion of a split was observed in all the scans. The Hα profile was broad and asymmetric. The composite [O III] and [N II] profiles were decomposed into two individual Gaussians for obtaining the expansion velocity.

scholarly journals The Central Region of the Planetary Nebula A58

1993 ◽  
Vol 155 ◽  
pp. 387-387
Author(s):  
D.L. Pollacco ◽  
P.W. Hill ◽  
R.E.S. Clegg
Keyword(s):  
High Resolution ◽  
Central Region ◽  
Planetary Nebula ◽  
Emission Lines

We present images and high–resolution spectra of the hydrogen deficient knot at the centre of the old planetary nebula A58. The spectra confirm that this region contains essentially no hydrogen, as previously suspected. Emission lines from the knot are broad (FWHM ∼ 180 and 270 km/s for [NII] and [OIII] lines respectively) and are blue–shifted by ∼100 km/s relative to the systematic velocity.

scholarly journals Near- and Mid-Infrared Imaging of the PN IC 418

1993 ◽  
Vol 155 ◽  
pp. 210-210
Author(s):  
J. L. Hora ◽  
L. K. Deutsch ◽  
W. F. Hoffmann ◽  
G. G. Fazio ◽  
K. Shivanandan
Keyword(s):  
High Resolution ◽  
Planetary Nebula ◽  
Infrared Imaging ◽  
Central Star ◽  
Infrared Images ◽  
Mid Infrared ◽  
Near Ir ◽  
Ir Emission ◽  
Array Camera ◽  
Infrared Array

We present high-resolution near- and mid-infrared images of the planetary nebula IC 418 at 1.2 (J), 1.6 (H), 2.2 (K), 9.8, and 11.7 μm. The near-IR images were obtained with a 64×64 pixel Hg:Cd:Te array camera, and the mid-IR images were obtained using the new 20×64 pixel Mid-Infrared Array Camera (MIRAC). The size of IC 418 in the near-IR is seen to vary with wavelength, being largest at K and smallest at J. Differences in the morphology of the nebula are seen between the J and K images. There is excess near-IR emission in the center of the nebula, after subtracting out the emission from the central star. Faint halo emission is detected at H and K, extending to a total diameter of approximately 40″. The 9.8 μm emission is distributed nonsymmetrically, with the peak in the NE lobe.

High‐Resolution X‐Ray Image of the Hydrogen‐deficient Planetary Nebula Abell 30

1997 ◽  
Vol 482 (2) ◽  
pp. 891-896 ◽  
Author(s):  
You‐Hua Chu ◽  
Thomas H. Chang ◽  
Gail M. Conway
Keyword(s):  
High Resolution ◽  
Planetary Nebula ◽  
X Ray
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