Benchmarking atomic data for astrophysics: a first look at the soft X-ray lines

Zanna, G. Del

doi:10.1051/0004-6361/201219923

Cited by 51 publications

(40 citation statements)

References 56 publications

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“…The third strongest line of the soft X-ray spectrum is the 3s 2 3p 5 3d 1 P 1 -3s3p 6 4s 1 S 0 (13-440) transition. We identified the same type of transitions (which are quite strong) for Fe x, Fe xi, Fe xii, and Fe xiii Del Zanna 2012a). Our "best" energy estimates predict this line to be around 104.6 Å.…”

Section: Discussion On Level Identificationssupporting

confidence: 60%

Atomic data for astrophysics: Ni XI

Zanna¹,

Storey

Badnell

2014

A&A

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We present a new large-scale R-matrix scattering calculation for electron collisional excitation of Ni xi, carried out with the intermediate-coupling frame transformation method. The target includes all the main configurations up to n = 4, and is a significant improvement over earlier R-matrix (only three n = 3 configurations) and distorted-wave (DW) calculations. We find significant enhancements in the collision strengths of many of the strong transitions to the n = 3, 4 levels. They are due to the resonances that arise within the present large-scale target. This results in significant increases in the predicted intensities of the UV and visible forbidden lines within the 3s 2 3p 5 3d configuration, the strong EUV lines that result from the decays of the 3s 2 3p 5 3d levels to the ground state, and the decays from the n = 4 levels, which are visible in the soft X-rays. We find good agreement between predicted and observed line intensities in the EUV. With the present atomic data, lines from Ni xi can reliably be used for plasma diagnostics. We also revise some level energies and suggest a few new possible identifications.

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Section: Discussion On Level Identificationssupporting

confidence: 60%

Atomic data for astrophysics: Ni XI

Zanna¹,

Storey

Badnell

2014

A&A

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“…The estimated wavelength in CHIANTI version 7.1 is 93.68 Å, while that one estimated by Del Zanna (2012a) is 93.49 Å. Note, however, that this wavelength has a significant uncertainty, considering that large discrepancies in the energies of the 3s 2 3p 2 4p levels have been found (Del Zanna 2012a). Figure 3 shows the AIA 94 Å responses calculated with the present data, together with previous CHIANTI versions.…”

Section: Aia 94 åmentioning

confidence: 55%

The multi-thermal emission in solar active regions

Zanna¹

2013

A&A

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159

110

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We present simultaneous SDO AIA and Hinode EIS observations of the hot cores of active regions (ARs) and assess the dominant contributions to the AIA EUV bands. This is an extension of our previous work. We find good agreement between SDO AIA, EVE and EIS observations, using our new EIS calibration and the latest EVE v.3 data. We find that all the AIA bands are multi-thermal, with the exception of the 171 and 335 Å, and provide ways to roughly estimate the main contributions directly from the AIA data. We present and discuss new atomic data for the AIA bands, showing that they are now sufficiently complete to obtain temperature information in the cores of ARs, with the exception of the 211 Å band. We found that the newly identified Fe xiv 93.61 Å line is the dominant contribution to the 94 Å band, whenever Fe xviii is not present. Three methods to estimate the Fe xviii emission in this band are presented, two using EIS and one directly from the AIA data. Fe xviii emission is often present in the cores of ARs, but we found cases where it is formed at 3 MK and not 7 MK, the temperature of peak ion abundance in equilibrium. The best EIS lines for elemental abundance determination and differential emission measure (DEM) analysis are discussed. A new set of abundances for many elements are obtained from EIS observations of hot 3 MK loops. The abundances of the elements with low first ionisation potential (FIP), relative to those of the high-FIP elements, are found to be enhanced by about a factor of three, compared to the photospheric values. A measurement of the path length implies that the absolute abundances of the low-FIP elements are higher than the photospheric values by at least a factor of three. We present a new DEM method customised for the AIA bands, to study the thermal structure of ARs at 1 resolution. This was tested on a few ARs, including one observed during the Hi-C rocket flight. We found excellent agreement between predicted and observed AIA count rates and EIS radiances. Overall we found few differences between the AIA and Hi-C 193 Å images of coronal structures, despite the higher Hi-C resolution (0.25 ). The Hi-C images and the AIA DEM modelling suggest that some of the cooler loops (below 1 MK) are already resolved by AIA, while the hotter (1.5-2.5 MK) "background" emission is in most places still unresolved even at the Hi-C resolution. This unresolved emission is significantly lower than previously observed with TRACE, the SOHO CDS, and Hinode EIS spectrometers. Its enhancement appears to be mostly due to increased iron abundance. We find an ubiquitous presence of emission at different temperatures that is not co-spatial, and suggest that future high-resolution imaging is carried out with isothermal bands.

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“…11 In summary, the original data sources include the following (for each ion): Fe II (Fuhr et al 1988;Nahar 1995;Zhang & Pradhan 1995) (Del Zanna et al 2004, 2012Del Zanna 2012). Charge exchange data is derived from Kingdon & Ferland (1996) and Ferland et al (1997).…”

Section: Treatment Of the Iron Ionsmentioning

confidence: 99%

Forbidden Iron Lines and Dust Destruction in Supernova Remnant Shocks: The Case of N49 in the Large Magellanic Cloud

Dopita

Seitenzahl

Sutherland

et al. 2016

ApJ

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We present the results of a complete integral-field survey of the bright supernova remnant (SNR) N49 in the Large Magellanic Cloud, obtained with the WiFeS instrument mounted on the ANU 2.3 m telescope at Siding Spring Observatory. From theoretical shock modeling with the new MAPPINGS 5.1 code, we have, for the first time, subjected the optical Fe emission line spectrum of an SNR to a detailed abundance and dynamical analysis covering eight separate stages of ionization. This allows us to derive the dust depletion factors as a function of ionization stage. We have shown that there is substantial (30%-90%) destruction of Fe-bearing dust grains in these fast shocks (v s ∼ 250 km s −1 ), and we have confirmed that the dominant dust destruction occurs through the nonthermal sputtering and grain-grain collision mechanisms developed in a number of theoretical works.

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Benchmarking atomic data for astrophysics: a first look at the soft X-ray lines

Cited by 51 publications

References 56 publications

Atomic data for astrophysics: Ni XI

Atomic data for astrophysics: Ni XI

The multi-thermal emission in solar active regions

Forbidden Iron Lines and Dust Destruction in Supernova Remnant Shocks: The Case of N49 in the Large Magellanic Cloud

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