Atomic data from the Iron project

Meléndez, M.; Bautista, M. A.

doi:10.1051/0004-6361:20042025

Cited by 6 publications

(2 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Within this project we have been systematically working on the data for the low ionization stages of iron peak elements, e.g. radiative and collisional rates for Fe i-iv (Bautista & Pradhan 1998), Ni ii (Bautista 2004), Ni iii (Bautista 2001), Ni iv (Meléndez & Bautista 2005). The objective of the present work is to provide accurate and complete atomic data for a detailed spectral modeling of Ca ii.…”

Section: Introductionmentioning

confidence: 99%

Atomic data from the IRON project

Meléndez

Bautista²,

Badnell

2007

A&A

Self Cite

View full text Add to dashboard Cite

Aims. This work reports radiative transition rates and electron impact excitation rate coefficients for levels of the n = 3, 4, 5, 6, 7, 8 configurations of Ca ii.Methods. The radiative data were computed using the Thomas-Fermi-Dirac central potential method in the frozen core approximation and includes the polarization interaction between the valence electron and the core using a model potential. This method allows for configuration interactions (CI) and relativistic effects in the Breit-Pauli formalism. Collision strengths in LS-coupling were calculated in the close coupling approximation with the R-matrix method. Then, fine structure collision strengths were obtained by means of the intermediate-coupling frame transformation (ICFT) method which accounts for spin-orbit coupling effects.Results. We present extensive comparisons with the most recent calculations and measurements for Ca ii as well as a comparison between the core polarization results and the "unpolarized" values. We find that core polarization affects the computed lifetimes by up to 20%. Our results are in very close agreement with recent measurements for the lifetimes of metastable levels. The present collision strengths were integrated over a Maxwellian distribution of electron energies and the resulting effective collision strengths are given for a wide range of temperatures. Our effective collision strengths for the resonance transitions are within ∼11% from previous values derived from experimental measurements, but disagree with later computations using the distorted wave approximation.

show abstract

Section: Introductionmentioning

confidence: 99%

Atomic data from the IRON project

Meléndez

Bautista²,

Badnell

2007

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…For atomic ions, new work has primarily focused on excitation and includes: C + (Wilson et al 2005), N + , O + (Tayal 2007), Al 12+ (Aggarwal et al 2005, 386 DIVISION XII / COMMISSION 14 / WORKING GROUP , S 4+ (Hudson & Bell 2006), Ar 16+ (Aggarwal & Keenan 2005b), Ca + (Meléndez et al 2007), Kr 6+ (Ishikawa & Vilkas 2008), Fe + (Ramsbottom et al 2007), Fe 3+ (McLaughlin et al 2006), Fe 4+ (Ballance et al 2007), Fe 6+ (Witthoeft & Badnell 2008), Fe 9+ (Aggarwal & Keenan 2005a), Fe 11+ (Storey et al 2005), Fe 15+ (Aggarwal & Keenan 2006), Fe 17+ (Witthoeft et al 2006), Fe 19+ (Witthoeft et al 2007), Fe 22+ (Chidichimo et al 2005), Fe 25+ , Ni 3+ (Meléndez & Bautista 2005), and for Si, Cl, and Ar isonuclear sequences (Colgan et al 2008).…”

Section: Electron-ion Scatteringmentioning

confidence: 99%

Division Xii / Commission 14 / Working Group Collision Processes

Peach¹,

Dimitrijević²,

Stancil³

2008

Proc. IAU

View full text Add to dashboard Cite

Research in atomic and molecular collision processes and spectral line broadening has been very active since our last report (Schultz & Stancil 2007, Allard & Peach 2007). Given the large volume of the published literature and the limited space available, we have attempted to identify work most relevant to astrophysics. Since our report is not comprehensive, additional publications can be found in the databases at the web addresses listed in the final section. Elastic and inelastic collisions among electrons, atoms, ions, and molecules are included and reactive processes are also considered, but except for charge exchange, they receive only sparse coverage.

show abstract

Signatures of Delayed Detonation, Asymmetry, and Electron Capture in the Mid‐Infrared Spectra of Supernovae 2003hv and 2005df

Gerardy

Meikle

Kotak

et al. 2007

ApJ

101

154

View full text Add to dashboard Cite

We present mid-infrared (5.2Y15.2 m) spectra of the Type Ia supernovae (SNe Ia) 2003hv and 2005df observed with the Spitzer Space Telescope. These are the first observed mid-infrared spectra of thermonuclear supernovae, and show strong emission from fine-structure lines of Ni, Co, S, and Ar. The detection of Ni emission in SN 2005df 135 days after the explosion provides direct observational evidence of high-density nuclear burning forming a significant amount of stable Ni in a SN Ia. The SN 2005df Ar lines also exhibit a two-pronged emission profile, implying that the Ar emission deviates significantly from spherical symmetry. The spectrum of SN 2003hv also shows signs of asymmetry, exhibiting blueshifted [Co iii], which matches the blueshift of [ Fe ii ] lines in nearly coeval near-infrared spectra. Finally, local thermodynamic equilibrium abundance estimates for the yield of radioactive 56 Ni give M56 Ni % 0:5 M , for SN 2003hv, but only M56 Ni % 0:13Y0:22 M for the apparently subluminous SN 2005df, supporting the notion that the luminosity of SNe Ia is primarily a function of the radioactive 56 Ni yield. The observed emission-line profiles in the SN 2005df spectrum indicate a chemically stratified ejecta structure, which matches the predictions of delayed detonation ( DD) models, but is entirely incompatible with current three-dimensional deflagration models. Furthermore, the degree that this layering persists to the innermost regions of the supernova is difficult to explain even in a DD scenario, where the innermost ejecta are still the product of deflagration burning. Thus, while these results are roughly consistent with a delayed detonation, it is clear that a key piece of physics is still missing from our understanding of the earliest phases of SN Ia explosions. Subject headingg s: supernovae: general -supernovae: individual (SN 2003hv, SN 2005df )

show abstract

Atomic data from the Iron project

Cited by 6 publications

References 23 publications

Atomic data from the IRON project

Atomic data from the IRON project

Division Xii / Commission 14 / Working Group Collision Processes

Signatures of Delayed Detonation, Asymmetry, and Electron Capture in the Mid‐Infrared Spectra of Supernovae 2003hv and 2005df

Contact Info

Product

Resources

About