Magnetic Field of HD119419 From Four Stokes Parameter Observations
Student paper other, 20 credits / 30 HE creditsStudent thesis
We have used a series of observations of HD119419, performed in 2012 and 2013at the European Southern Observatory 3.6-m telescope in La Silla, Chile. These are high resolutionspectropolarimetric observations with coverage in all four Stokes parameters.
We performed a chemical abundance analysis of HD119419, in the absence of any being published previously for this star. We used a LLmodels stellar atmosphere code with effective temperature11500 K and surface gravity log g = 4.0, together with the spectrum synthesis code synmast. Abundances were adjusted until the synthetic spectra matched the mean observed spectra as well as possible, and these abundances were assumed to be representative of the photosphere of HD119419. We found good estimates for some Fe-peak elements and rare-earth elements.
The abundance estimates were used to compute least-squares deconvolution Stokes spectra, from which we calculated how the longitudinal magnetic field and net linear polarization varies with rotational phase for HD119419.
We calculated an improved rotational period for HD119419 using our longitudinal magnetic field measurements together with previous measurements from the literature, determining it to be 2.60059(1) days.
We found that the Stokes QUV are unusually strong for the rare-earth elements in HD119419, considering their weaker Stokes I profiles compared to the Fe-peak elements in particular.
Place, publisher, year, edition, pages
2015. , 23 p.
magnetic, HD119419, HD 119419, Stokes, Chemically peculiar, Ap, Ap/Bp, Cp, polarisation, polarization, Zeeman effect, LSD, least-squares deconvolution, abundance, abundance anlysis, longitudinal magnetic field, rotational period, period
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:uu:diva-260223OAI: oai:DiVA.org:uu-260223DiVA: diva2:846715
2015-06-12, 14:30 (English)
Kochukhov, Oleg, universitetslektorRusomarov, Naum, Doktorand
Edvardsson, Bengt, Universitetslektor