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Related papers: New advances in photoionisation codes: How and wha…

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We present literature on abundance determinations in planetary nebulae (PN) as well as public tools that can be used to derive them. Concerning direct methods to derive abundances we discuss in some depth such issues as reddening…

Astrophysics of Galaxies · Physics 2023-12-05 Grazyna Stasinska

We describe a pseudo-3D photoionization code, NEBU_3D and its associated visualization tool, VIS_NEB3D, which are able to easily and rapidly treat a wide variety of nebular geometries, by combining models obtained with a 1D photoionization…

Astrophysics · Physics 2009-11-13 C. Morisset , G. Stasinska , M. Pena

Accurate emission line fluxes from planetary nebulae (PNe) provide important constraints on the nature of the final phases of stellar evolution. Large, evolved PNe may trace the latest stages of PN evolution, where material from the AGB…

Astrophysics · Physics 2009-11-11 G. J. Madsen , D. J. Frew , Q. A. Parker , R. J. Reynolds , L. M. Haffner

We briefly describe the current version of the PHOENIX code. We then present some illustrative results from the modeling of Type Ia and Type II supernovae, hot stars, and irradiated giant planets. Good fits to observations can be obtained,…

Planetary nebulae (PNe) are pivotal for advancing our knowledge of stellar evolution and galactic chemical enrichment. Recent progress in surveys and data analysis has revolutionized PN research, leading to the discovery of new objects and…

Solar and Stellar Astrophysics · Physics 2025-05-27 L. A. Gutiérrez-Soto , M. Belén Mari , W. A. Weidmann , F. R. Faifer

Many of the fundamental questions in astrophysics can be addressed using spectroscopic observations of photoionized cosmic plasmas. However, the reliability of the inferred astrophysics depends on the accuracy of the underlying atomic data…

Astrophysics · Physics 2007-05-23 Daniel Wolf Savin

Coded-illumination can enable quantitative phase microscopy of transparent samples with minimal hardware requirements. Intensity images are captured with different source patterns and a non-linear phase retrieval optimization reconstructs…

Signal Processing · Electrical Eng. & Systems 2019-02-07 Michael R. Kellman , Emrah Bostan , Nicole Repina , Laura Waller

Photoionized nebulae, comprising HII regions and planetary nebulae, are excellent laboratories to investigate the nucleosynthesis and chemical evolution of several elements in the Galaxy and other galaxies of the Local Group. Our purpose in…

Astrophysics of Galaxies · Physics 2017-02-14 W. J. Maciel , R. D. D. Costa , O. Cavichia

Since the last IAU symposium on planetary nebulae (PNe), several deep spectroscopic surveys of the relatively faint optical recombination lines (ORLs) emitted by heavy element ions in PNe and H II regions have been completed. New diagnostic…

Astrophysics · Physics 2009-11-11 X. -W. Liu

A hot central star illuminating the surrounding ionized H II region usually produces very rich atomic spectra resulting from basic atomic processes: photoionization, electron-ion recombination, bound-bound radiative transitions, and…

Astrophysics · Physics 2007-05-23 Sultana N. Nahar

We present a detailed model of the discrete X-ray spectroscopic features expected from steady-state, low-density photoionized plasmas. We apply the Flexible Atomic Code (FAC) to calculate all of the necessary atomic data for the full range…

Astrophysics · Physics 2007-05-23 A. Kinkhabwala , E. Behar , M. Sako , M. F. Gu , S. M. Kahn , F. B. S. Paerels

Our understanding of planetary nebulae has been significantly enhanced as a result of several recent large surveys (Parker et al., these proceedings). These new discoveries suggest that the `PN phenomenon' is in fact more heterogeneous than…

Astrophysics of Galaxies · Physics 2015-06-04 D. J. Frew , Q. A. Parker

Extragalactic planetary nebulae (PNe) are detectable through relatively strong nebulous [OIII] emission and act as direct probes into the local stellar population. Because they have an apparently universal invariant magnitude cut-off, PNe…

The recent HST optical images, and the optical and ultraviolet spectra, of Magellanic planetary nebulae (PNe), together with the large data-base that has been collected in the past decade, allows unprecedented insight in the evolution of…

Astrophysics · Physics 2007-05-23 Letizia Stanghellini

Photoelectron angular distributions (PADs) obtained from ionization of potassium atoms using moderately intense femtosecond IR fields ($\sim$10$^{12}$Wcm$^{-2}$) of various polarization states are shown to provide a route to "complete"…

Atomic Physics · Physics 2015-01-15 Paul Hockett , Matthias Wollenhaupt , Christian Lux , Thomas Baumert

Photoionization and its inverse, electron-ion recombination, are key processes that influence many astrophysical plasmas (and gasses), and the diagnostics that we use to analyse the plasmas. In this review we provide a brief overview of the…

Solar and Stellar Astrophysics · Physics 2023-03-21 D. John Hillier

Recent weak emission-line long-slit surveys and modelling studies of PNe have convincingly argued in favour of the existence of an unknown component in the planetary nebula plasma consisting of cold, hydrogen-deficient gas, as an…

Astrophysics · Physics 2009-11-11 Y. G. Tsamis , J. R. Walsh , D. Pequignot , M. J. Barlow , X. -W. Liu , I. J. Danziger

We have conducted a large-scale survey of 120 planetary nebulae (PNe) to search for the near-infrared emission lines [Kr III] 2.199 and [Se IV] 2.287 microns. The neutron(n)-capture elements Se and Kr may be enriched in a PN if its…

Astrophysics · Physics 2007-05-23 N. C. Sterling , Harriet L. Dinerstein , T. R. Kallman

How well do we know the physical/chemical properties of PNe? 1D (CLOUDY) and 3D (MOCASSIN) photoionisation codes are used in this contribution to model the PNe K 4-47 and NGC 7009 as an attempt to question whether or not the high Te (higher…

Astrophysics · Physics 2016-08-30 Denise R. Goncalves

The study of extragalactic planetary nebulae (EPN) is a rapidly expanding field. The advent of powerful new instrumentation such as the PN spectrograph has led to an avalanche of new EPN discoveries both within and between galaxies. We now…

Astrophysics · Physics 2015-06-24 Quentin A Parker , Richard Shaw