Theoretical energies for the <i>n</i> = 1 and 2 states of the helium isoelectronic sequence up to <i>Z</i> = 100

Drake, G. W. F.

doi:10.1139/p88-100

Cited by 512 publications

(481 citation statements)

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“…1828 3 Sl-1s2p 3 PO,2 transitions of He-like species are of particular interest for theoretical physics: accurate wavelength measurements of the transitions are used as benchmarks for comparisons with calculations of both relativistic and quantum-electrodynamical effects in 3-body systems (Drake 1988). We have identified He-like lines from Ne 8+ to Si12+ and believe that our measurements of these wavelengths are the first to be done from collisional astrophysical plasmas (cf., Curdt et al 2000).…”

Section: Spectroscopic Features In the Euv Emission Of A M8 Flarementioning

confidence: 93%

Spectroscopic Features in the EUV Emission of a M8 Flare Observed by SUMER

Curdt

Landi

Feldman³

et al. 2001

Symp. - Int. Astron. Union

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Abstract.A flare of size M8 occurred while SUMER was recording a spectral scan above the active region NOAA 8537 at the west limb. We recorded spectra during the pre-Hare phase, at Hare onset, and during the decay phase of this main flare in a series of events. More than 60 flare lines were identified during this observation, which include Fe XVIII -Fe XXIII lines that provide evidence of 10 7 K plasmas. We also recorded lines from He-like ions, such as Ne IX, Na x, Mg XI, and Si XIII. Accurate wavelength measurements of such lines are of interest in basic atomic physics studies. Using plasma diagnostic techniques, we investigated the temporal evolution of the electron densities and temperatures during the event.

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Section: Spectroscopic Features In the Euv Emission Of A M8 Flarementioning

confidence: 93%

Spectroscopic Features in the EUV Emission of a M8 Flare Observed by SUMER

Curdt

Landi

Feldman³

et al. 2001

Symp. - Int. Astron. Union

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“…Discrete recombination lines from He-and H-like species are present in the MOS and PN spectra of 4U 1538−52. The energy resolution of the instruments is not sufficient to resolve the lines clearly (Drake 1988;Hojnacki et al 2007). Therefore, our identification could be a blend of other emission lines.…”

Section: Detecting Emission Lines In the Eclipse Spectrummentioning

confidence: 94%

“…We fitted these lines as Gaussian profiles (see Table 3 for parameter values). Because the energy resolution of the EPIC cameras is not high enough to resolve all Drake 1988;Hojnacki et al 2007). Figure 4 clearly shows the presence of the Fe Kα line at ∼6.4 keV, but a second broad emission line around 6.65 keV or an absorption edge at ∼7.2 keV associated with low-ionization iron is an unresolved issue within the deviation for PN and MOS ratios.…”

Section: Emission Linesmentioning

confidence: 99%

Detecting emission lines withXMM-Newtonin 4U 1538–52

Roca

Page

Torrejón

et al. 2010

A&A

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Context. The properties of the X-ray emission lines are a fundamental tool for studying the nature of the matter surrounding the neutron star and the phenomena that produce these lines. Aims. The aim of this work is to analyse the X-ray spectrum of 4U 1538−52 obtained by the XMM-Newton observatory and to look for the presence of diagnostic lines in the energy range 0.3−11.5 keV. Methods. We used a 54 ks PN & MOS/XMM-Newton observation of the high-mass X-ray binary 4U 1538−52 covering the orbital phase between 0.75 to 1.00 (the eclipse ingress). We modelled the 0.3−11.5 keV continuum emission with three absorbed power laws and looked for the emission lines. Results. We found previously unreported recombination lines in this system at ∼2.4 keV, ∼1.9 keV, and ∼1.3 keV, which is consistent with the presence of highly ionized states of S XV Heα, Si XIII Heα, and either Mg Kα or Mg XI Heα. On the other hand, in spectra that are both out of eclipse and in eclipse, we detect a fluorescence iron emission line at 6.4 keV, which is resolved into two components: a narrow (σ ≤ 10 eV) fluorescence Fe Kα line plus one hot line from highly photoionized Fe XXV. Conclusions. The detection of new recombination lines during eclipse ingress in 4U 1538−52 indicates that there is an extended ionized region surrounding the neutron star.

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“…3 and 4). They were calibrated with the very well known 1s -np transitions in H-like C 6+ ions, and 1s 2 1 S 0 -1s2p 1,3 P 1 and 1s 2 1 S 0 -1s3p 1 P 1 transitions in He-like ions of N [16,17,18,19]. Each of these is known to better than 1 mÅ.…”

Section: Methodsmentioning

confidence: 99%

Soft-X-ray spectra of highly charged Os, Bi, Th, and U ions in an electron beam ion trap

Beiersdörfer¹,

Fournier²,

Chen³

2005

Can. J. Phys.

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Systematic variation of the electron-beam energy in an electron-beam ion trap has been employed to produce soft-X-ray spectra of Os, Bi, Th, and U with highest charge states ranging up to Ni-like ions. Guided by relativistic atomic structure calculations, the strongest lines have been identified with ∆n=0 (n=4 to n =4) transitions in Rb-to Cu-like ions. The rather weak 4p-4d transitions are much less affected by QED contributions than the dominant 4s-4p transitions. Our wavelength measurements consequently provide benchmarks with and (almost) without QED. Because the radiative corrections are not very sensitive to the number of electrons in the valence shell, our data, moreover, provide benchmarks for the evaluation of electron-electron interactions.Résumé francais: (traduit par le journal)

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Theoretical energies for the n = 1 and 2 states of the helium isoelectronic sequence up to Z = 100

Cited by 512 publications

References 0 publications

Spectroscopic Features in the EUV Emission of a M8 Flare Observed by SUMER

Spectroscopic Features in the EUV Emission of a M8 Flare Observed by SUMER

Detecting emission lines withXMM-Newtonin 4U 1538–52

Soft-X-ray spectra of highly charged Os, Bi, Th, and U ions in an electron beam ion trap

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