Analysis of the 3d64s(6D)6dsubconfiguration of Fe I by laser-enhanced ionisation and emission spectroscopy

Nave, Gillian; Johansson, Sveneric; Axner, Ove; Ljungberg, Peter; Malmsten, Yvonne; Baschek, B.

doi:10.1088/0031-8949/49/5/014

Cited by 11 publications

(3 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Blueward of 5000 the Kurucz 1998 May 25 atomic line A , lists gf 0300.100, gf 0400.100, and gf 00500.100 were used. These di †er signiÐcantly from those used in the Kurucz Ñux distribution calculations in including only atomic lines identiÐed in the laboratory (with laboratory gf-values where available)Èlike those of Kurucz & Bell (1995) but with the addition of many lines of Fe I, Fe II, and other species whose upper energy levels were newly determined in near-UV laboratory spectra (e.g., Nave et al 1994). Because the strengths or proÐles of many lines were mismatched when using line parameters directly from this list, their gf-values and damping constants were changed where necessary, as described shortly.…”

Section: Spectrum Analysismentioning

confidence: 85%

Modeling Mid‐Ultraviolet Spectra. I. Temperatures of Metal‐poor Stars

Peterson

Dorman

Rood

2001

ApJ

View full text Add to dashboard Cite

Determining the properties of remote globular clusters and elliptical galaxies using evolutionary population synthesis requires a library of reliable model stellar Ñuxes. Empirical libraries are limited to spectra of stars in the solar neighborhood, with nearly solar abundances and abundance ratios. We report here a Ðrst step toward providing a Ñux library that includes nonsolar abundances, based on calculations from Ðrst principles that are calibrated empirically. Because the mid-ultraviolet spectrum of an old stellar system is dominated by the contribution from its main-sequence turno † stars, we have started by modeling these.We have calculated mid-ultraviolet spectra for the Sun and nine nearby, nearÈmain-sequence stars spanning metallicities from less than 1/100 solar to greater than solar, encompassing a range of lightelementÈabundance enhancements. We Ðrst determined temperatures of eight of the stars by analyzing optical echelle spectra together with the mid-ultraviolet. Both could be matched at the same time only when models with no convective overshoot were adopted and only when an approximate chromosphere was incorporated near the surface of relatively metal-rich models. Extensive modiÐcations to mid-UV line parameters were also required, notably the manual assignment of approximate identiÐcations for mid-UV lines missing from laboratory line lists. Without recourse to additional missing opacity, these measures suffice to reproduce in detail almost the entire mid-UV spectrum of solar-temperature stars up to 1/10 solar metallicity and the region from 2900 to 3100 throughout the entire metallicity range. A RamiÐcations for abundance determinations in individual metal-poor stars and for age-metallicity determinations of old stellar systems are brieÑy discussed, with emphasis on the predictive power of the calculations.

show abstract

Section: Spectrum Analysismentioning

confidence: 85%

Modeling Mid‐Ultraviolet Spectra. I. Temperatures of Metal‐poor Stars

Peterson

Dorman

Rood

2001

ApJ

View full text Add to dashboard Cite

show abstract

“…The table for Fe I in the AEL-SC incorporates the revised levels of Crosswhite (1975) and Litzén (1976) and contains a list of references to earlier work. Since 1985, revisions to the energy levels and extensions to the term system have been made by Johansson (1987), Brown et al (1988), O'Brian et al (1991, Zhu and Knight (1992); further extensions based on the spectra presented in the current paper have been published by Johansson and Learner (1990), Nave and Johansson (1993a,b), Nave et al (1994), andJohansson et al (1994). Bièmont et al (1985) have also compiled a list of Fe I lines in the infrared solar spectrum.…”

Section: Introductionmentioning

confidence: 95%

A new multiplet table for Fe I

Nave¹,

Johansson²,

Learner³

et al. 1994

ApJS

340

344

View full text Add to dashboard Cite

We have recorded spectra of iron-neon and iron-argon hollow cathode lamps in the region 1700Å -5 µm (59 000 -2000 cm −1 ), with Fourier transform (FT) spectrometers at the National Solar Observatory, Tucson, Arizona, U.S.A. and Imperial College, London, U.K., and with a high resolution grating spectrograph at the National Institute of Standards and Technology, Gaithersburg, U.S.A. The uncertainty of the strongest lines in the FT spectra is <0.002 cm −1 (0.2 mÅ at 3000Å; 8 mÅ at 2 µm ). Pressure and current-dependent shifts are <0.001 cm −1 for transitions between low lying levels, increasing to 0.006 cm −1 for transitions between the most highly excited levels. We report 28 new energy levels of Fe I and revised values of another 818 levels. We have identified 9501 lines as due to 9759 transitions in Fe I, and these are presented in the form of a new multiplet table and finding list. This compares with the ∼5500 lines due to 467 energy levels in the multiplet tables of Moore (1950, 1959). The biggest increase is in the near ultraviolet and near infra-red, and many of the new lines are present in the solar spectrum. Experimental log(gf) values are included where they are available. A further 125 unidentified lines due to Fe I are given. The tables are also available in computer-readable form.

show abstract

“…We also downloaded the Kurucz (1991) grid of ATLAS9 models and colors, and the line lists gf 0400.100 and gf 0050.100 dated 25-May-98. As described by Kurucz (1995), they differ from those of Kurucz & Bell (1995) in incorporating for many iron-group species all newly identified and revised transitions whose energy levels were measured recently by Nave et al (1994) and other laboratory groups. Moreover, they include only atomic lines identified in the laboratory.…”

Section: Spectrum Analysismentioning

confidence: 95%

Hot Horizontal‐Branch Stars in the Galactic Bulge. I.

Peterson

Terndrup

Sadler

et al. 2001

ApJ

View full text Add to dashboard Cite

We present the Ðrst results of a survey of blue horizontal-branch (BHB) stars in the Galactic bulge. In this exploratory study, candidates with 15 ¹ V ¹ 17.5 covering a wide range in B[V color were selected from Cerro Tololo Inter-American Observatory (CTIO) Schmidt UBV photometry. Blue spectra were recorded at 2.4 FWHM resolution for 164 stars in a 1.3 deg2 Ðeld, from the Galactic center. Ó D7¡ .5 Radial velocities were measured for all stars. For stars with strong Balmer lines, we devised and applied a spectroscopic technique to determine stellar temperature gravity log g, and metallicity [Fe/H] T eff , independent of reddening. The reddening and distance to each star were then found from UBV photometry. Forty-seven BHB candidates were identiÐed with K. Seven have the gravities of Popu-T eff º 7250 lation I stars, three are ambiguous, and 37 are HB stars, including perhaps a dozen RR Lyrae stars. The unambiguous BHB stars are all cooler than 9000 K. They span a wide metallicity range, from solar to 1/300 solar. The warmer BHB stars are more metal-poor and loosely concentrated toward the Galactic center, while the cooler ones are of somewhat higher metallicity and are situated closer to the center. We detect two cool solar-metallicity HB stars in the bulge of our own Galaxy, the Ðrst such stars known. Still elusive are their fainter hot counterparts, the metal-rich sdB/O stars strong in ultraviolet light.

show abstract

Analysis of the 3d⁶4s(⁶D)6dsubconfiguration of Fe I by laser-enhanced ionisation and emission spectroscopy

Cited by 11 publications

References 7 publications

Modeling Mid‐Ultraviolet Spectra. I. Temperatures of Metal‐poor Stars

Modeling Mid‐Ultraviolet Spectra. I. Temperatures of Metal‐poor Stars

A new multiplet table for Fe I

Hot Horizontal‐Branch Stars in the Galactic Bulge. I.

Contact Info

Product

Resources

About