Project VeSElkA: results of abundance analysis I – HD 71030, HD 95608, HD 116235 and HD 186568

Leblanc, F.; Khalack, V.; Yameogo, B.; Thibeault, C.; Gallant, I.

doi:10.1093/mnras/stv1466

Cited by 12 publications

(11 citation statements)

References 39 publications

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“…Several stars from this sample have already been analyzed and some of them revealed signatures of vertical stratification of metals. HD 22920 shows vertical stratification of Cr (Khalack & Poitras 2015), HD 95608 and HD 116235 show vertical stratification of Fe and Cr (LeBlanc et al 2015), while HD 41076 and HD 148330 show vertical stratification of several metals (Khalack et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Project VeSElkA: results of abundance analysis for HD 53929 and HD 63975

N'Diaye

Leblanc

Khalack

2018

Monthly Notices of the Royal Astronomical Society

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Project VeSElkA (Vertical Stratification of Element Abundances) has been initiated with the aim to detect and study the vertical stratification of element abundances in the atmosphere of chemically peculiar stars. Abundance stratification occurs in hydrodynamically stable stellar atmospheres due to the migration of the elements caused by atomic diffusion. Two HgMn stars, HD 53929 and HD 63975 were selected from the VeSElkA sample and analysed with the aim to detect some abundance peculiarities employing the ZEEMAN2 code. We present the results of abundance analysis of HD 53929 and HD 63975 observed recently with the spectropolarimeter ESPaDOnS at Canada-France-Hawaii Telescope. Evidence of phosphorus vertical stratification was detected in the atmosphere of these two stars. In both cases, phosphorus abundance increases strongly towards the superficial layers. The strong overabundance of Mn found in stellar atmosphere of both stars confirms that they are HgMn type stars.

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Section: Introductionmentioning

confidence: 99%

Project VeSElkA: results of abundance analysis for HD 53929 and HD 63975

N'Diaye

Leblanc

Khalack

2018

Monthly Notices of the Royal Astronomical Society

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“…A number of the upper main sequence CP stars observed in the frame of the VeSElkA project (Khalack & LeBlanc 2015a;Khalack & LeBlanc 2015b) have been studied using the aforementioned approach. The abundance analysis resulted in detection of indications of vertical stratification of iron abundance in stellar atmosphere of HD 95608 and HD 116235 (Khalack et al 2013;LeBlanc et al 2015) and of chromium abundance in stellar atmosphere of HD 22920 (Khalack & Poitras 2015). Here, we presented our estimate of the effective temperature, gravity and metallicity (see Fig.…”

Section: Discussionmentioning

confidence: 99%

“…In the first approach we can use the high-resolution (R=60000) and high signal-to-noise ratio (S/N¿250) spectra to derive from the fitting procedure values of the free model parameters with a precision sufficiently high to track the abundance variation with optical depth (Khalack et al 2014;Khalack & Poitras 2015;LeBlanc et al 2015). The spectra with lower resolution (R=45000) and smaller S/N ratio also can be used, but the fitting procedure will results in a lower precision of abundance estimates (Khalack et al 2007; Khalack et al 2008; Khalack et al 2010).…”

Section: First Approachmentioning

confidence: 99%

Project VeSElkA: abundance analysis of chemical species in HD 41076 and HD 148330

Khalack¹,

Gallant²,

Thibeault³

2017

Monthly Notices of the Royal Astronomical Society

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A new semi-automatic approach is employed to carry out the abundance analysis of highresolution spectra of HD 41076 and HD 148330 obtained recently with the spectropolarimetre ESPaDOnS at the CFHT. This approach allows to prepare in a semi-automatic mode the input data for the modified ZEEMAN2 code and to analyse several hundreds of line profiles in sequence during a single run. It also provides more information on abundance distribution for each chemical element at the deeper atmospheric layers. Our analysis of the Balmer profiles observed in the spectra of HD 41076 and HD 148330 has resulted in the estimates of their effective temperature, gravity, metallicity and radial velocity. The respective models of stellar atmosphere have been calculated with the code PHOENIX and used to carry out abundance analysis employing the modified ZEEMAN2 code. The analysis shows a deficit of the C, N, F, Mg, Ca, Ti, V, Cu, Y, Mo, Sm and Gd, and overabundance of Cr, Mn, Fe, Co, Ni, Sr, Zr, Ba, Ce, Nd and Dy in the stellar atmosphere of HD 41076. In the atmosphere of HD 148330, the C, N and Mo appear to be underabundant, while the Ne, Na, Al, Si, P, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Sr, Y, Zr, Ba, Ce, Pr, Nd, Sm, Eu, Gd and Dy are overabundant. We also have found signatures of vertical abundance stratification of Fe, Ti, Cr and Mn in HD 41076, and of Fe, Ti, V, Cr, Mn, Y, Zr, Ce, Nd, Sm and Gd in HD 148330.

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“…In this way, the magnetic eld can stabilise the structure of abundance peculiarities in atmospheres of magnetic CP stars, so that they remain stable over more than fty years of spectral observations [41,50]. Therefore, for a comprehensive study of the structure of stellar atmospheres in CP stars, it is important to detect and observationally estimate the intensity of vertical abundance stratication of dierent chemical species [30,38]. Such detections are the main goal of Project VeSElkA.…”

Section: Espadons Acquires High Resolution (R = 65000)mentioning

confidence: 99%

“…The obtained stellar atmosphere parameters have been used to calculate homogeneous stellar atmosphere models, which were employed to perform an abundance analysis of HD 22920, HD 23878, HD 95608, HD 116235 and HD 186568 [28,29,38] with the help of the modied ZEEMAN2 code [24,25]. Among the studied CP stars, signatures of vertical stratication of silicon and chromium abundances were found in HD 22920 [29], and of iron and chromium abundances in HD 95608 and HD 116235 [28,38]. in a single exposure [11].…”

Section: Espadons Acquires High Resolution (R = 65000)mentioning

confidence: 99%

Project VeSElkA: Vertical Stratification of Element Abundances in CP stars

Khalack

Leblanc

2015

Adv.Astron.Spa.Physics

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A new research project on spectral analysis which aims to characterize the vertical stratication of element abundances in stellar atmospheres of chemically peculiar (CP) stars, is discussed in detail. Some results on detection of vertical abundance stratication in several slowly rotating main sequence CP stars are presented and considered as an indicator of the eectiveness of the atomic diusion mechanism responsible for the observed peculiarities of chemical abundances. This study is carried out in the frame of Project VeSElkA (Vertical Stratication of Elements Abundance) for which 34 slowly rotating CP stars have been observed with the ESPaDOnS spectropolarimetre at CFHT.

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Project VeSElkA: results of abundance analysis I – HD 71030, HD 95608, HD 116235 and HD 186568

Cited by 12 publications

References 39 publications

Project VeSElkA: results of abundance analysis for HD 53929 and HD 63975

Project VeSElkA: results of abundance analysis for HD 53929 and HD 63975

Project VeSElkA: abundance analysis of chemical species in HD 41076 and HD 148330

Project VeSElkA: Vertical Stratification of Element Abundances in CP stars

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