Results 11 to 20 of about 207,371 (176)
Radio Continuum Spectra of Planetary Nebulae
Galaxies, 2018 Radio continuum emission of planetary nebulae is a rich source of information about their structure and physical parameters. Although radio emission is well studied, planetary nebulae show higher spectral indices than expected for homogeneous sphere.
Marcin Hajduk +6 more
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Current Unsolved Problems in Planetary Nebulae Research
GalaxiesWhile there has been significant progress in our understanding of the origin and evolution of planetary nebulae in the last 50 years, there remain several unsolved problems.
Sun Kwok +7 more
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Planetary Nebulae Research: Past, Present, and Future [PDF]
GalaxiesWe review the evolution of our understanding of the planetary nebulae phenomenon and their place in the scheme of stellar evolution. The historical steps leading to our current understanding of central star evolution and nebular formation are discussed ...
Sun Kwok
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X-ray Observations of Planetary Nebulae since WORKPLANS I and Beyond
Galaxies, 2020 Planetary nebulae (PNe) were expected to be filled with hot pressurized gas driving their expansion. ROSAT hinted at the presence of diffuse X-ray emission from these hot bubbles and detected the first sources of hard X-ray emission from their central ...
Martín A. Guerrero
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Third-dredge-up oxygen in planetary nebulae [PDF]
, 2000 The planetary nebulae He 2-436 and Wray 16-423 in the Sagittarius dwarf galaxy appear to result from nearly twin stars, except that third-dredge-up carbon is more abundant in He 2-436. A thorough photoionization-model analysis implies that ratios Ne/O, S/
Dudziak, G. +3 more
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X-ray Shaping of Planetary Nebulae
Galaxies, 2018 The stellar winds of the central stars of planetary nebulae play an essential role in the shaping of planetary nebulae. In the interacting stellar winds model, the fast stellar wind injects energy and momentum, which are transferred to the nebular ...
Martín A. Guerrero
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Preface of “Asymmetric Planetary Nebulae 8e”
Galaxies, 2022 Planetary nebulae (PNe) are the progeny of low- and intermediate-mass stars, at the exact time in their late evolution when they eject their hydrogen-rich envelopes and start their transition towards white dwarfs [...]
Martin A. Guerrero +2 more
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On the Age of Galactic Bulge CSPNe: Too Young and Complicated?
Galaxies, 2020 We present preliminary results of our study of a small sample of planetary nebulae in the Galactic Bulge for which high-angular resolution Hubble Space Telescope imaging is available.
Foteini Lykou +2 more
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MULTI-STAGES OPTIMIZED PHOTOIONIZATION MODELLING OF PLANETARY NEBULA LMC SMP-21
Odessa Astronomical Publications, 2012 The new approximation expression for the representation of gas density distribution in planetary nebulae envelopes was proposed. The new multi-stages method for the caclulation of the chemical composition and physical parameters of planetary nebulae ...
B. Ya. Melekh +5 more
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(Sub)mm-Wavelength Observations of Pre-Planetary Nebulae and Young Planetary Nebulae
Galaxies, 2020 This is a non-comprehensive review of observations of pre-Planetary Nebulae (pPNe) and young Planetary Nebulae (yPNe) at (sub)mm-wavelengths, a valuable window for probing multi-phased gas and dust in these objects.
Carmen Sánchez Contreras
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