Matches in SemOpenAlex for { <https://semopenalex.org/work/W2005371035> ?p ?o ?g. }
Showing items 1 to 80 of
80
with 100 items per page.
- W2005371035 endingPage "794" @default.
- W2005371035 startingPage "781" @default.
- W2005371035 abstract "We present precise relative radial velocity (RV) measurements for the rapidly oscillating Ap (roAp) star 33 Librae measured from high-resolution data spanning the wavelength interval 5000–6200 A. We find that the pulsational radial velocity amplitude determined over a broad wavelength range (≈100 A) depends on the spectral region that is examined and can be as high as 60 m s−1 at 5600 A and as low as 7 m s−1 in the 5900 A region. RV measurements of individual spectral lines can show higher amplitudes than results obtained using a ‘broad-band’ measurement that includes many spectral lines. The acoustic cross-sections of the atmosphere, i.e. the phase and amplitude of the pulsations, as a function of optical depth are found for spectral lines of Ca, Cr, Fe, La, Ce, Gd, Er and Nd. This analysis shows that pulsation phase is variable through the atmosphere and that Nd iii lines pulsate almost 180° out of phase with those of Nd ii features and are formed significantly higher in the stellar atmosphere. This conclusively establishes the presence of at least one radial node to the pulsations in the upper stellar atmosphere. We have estimated that this acoustic node is located above an optical depth log τ < −4.5 and below the level where the Nd iii lines are formed. We also suspect that there may be a second atmospheric node in the lower atmosphere below or at log τ≃−0.9 and close to continuum formation level.The histogram of pulsational phases for all individual spectral features shows a bimodal Gaussian distribution with 17 per cent of the lines having a pulsational phase ≈165° out of phase with most other spectral lines. This is also consistent with the presence of a radial node in the stellar atmosphere. The accumulation of phase due to a running wave component can explain the 165° phase difference as well as the broader width (by a factor of 2) of one of the Gaussian components of the phase distribution.We also found evidence for phase variations as a function of effective Landeg-factors. This may be the influence of magnetic field and magnetic intensification effect on depths of spectral line formation and shows that the magnetic field is controlling the pulsations. Our RV measurements for 33 Lib suggest that we are seeing evidence of vertical structure to the oscillations as well as the influence of the distribution of elements on the stellar surface.We suggest and briefly discuss a new semi-empirical tomographic procedure for mono- and multimode roAp stars that will use acoustic cross-sections obtained on different chemical elements and different pulsation modes for restoring the abundance and acoustic profiles throughout the stellar atmosphere and across the stellar surface." @default.
- W2005371035 created "2016-06-24" @default.
- W2005371035 creator A5020332782 @default.
- W2005371035 creator A5044207777 @default.
- W2005371035 creator A5047808099 @default.
- W2005371035 date "2003-11-01" @default.
- W2005371035 modified "2023-10-03" @default.
- W2005371035 title "Radial velocity variations in pulsating Ap stars - II. 33 Librae" @default.
- W2005371035 cites W1658542051 @default.
- W2005371035 cites W1710938835 @default.
- W2005371035 cites W178648595 @default.
- W2005371035 cites W1985601475 @default.
- W2005371035 cites W1986316936 @default.
- W2005371035 cites W2016268550 @default.
- W2005371035 cites W2038844072 @default.
- W2005371035 cites W2044119909 @default.
- W2005371035 cites W2062225125 @default.
- W2005371035 cites W2067366609 @default.
- W2005371035 cites W2079493947 @default.
- W2005371035 cites W2079624808 @default.
- W2005371035 cites W2080880313 @default.
- W2005371035 cites W2087015211 @default.
- W2005371035 cites W2088735077 @default.
- W2005371035 cites W2103204974 @default.
- W2005371035 cites W2109579875 @default.
- W2005371035 cites W2112675814 @default.
- W2005371035 cites W2113207832 @default.
- W2005371035 cites W2152575109 @default.
- W2005371035 cites W2615108302 @default.
- W2005371035 cites W3043579296 @default.
- W2005371035 cites W4242284424 @default.
- W2005371035 cites W60795444 @default.
- W2005371035 doi "https://doi.org/10.1046/j.1365-8711.2003.07002.x" @default.
- W2005371035 hasPublicationYear "2003" @default.
- W2005371035 type Work @default.
- W2005371035 sameAs 2005371035 @default.
- W2005371035 citedByCount "59" @default.
- W2005371035 countsByYear W20053710352012 @default.
- W2005371035 countsByYear W20053710352013 @default.
- W2005371035 countsByYear W20053710352014 @default.
- W2005371035 countsByYear W20053710352016 @default.
- W2005371035 countsByYear W20053710352018 @default.
- W2005371035 countsByYear W20053710352022 @default.
- W2005371035 crossrefType "journal-article" @default.
- W2005371035 hasAuthorship W2005371035A5020332782 @default.
- W2005371035 hasAuthorship W2005371035A5044207777 @default.
- W2005371035 hasAuthorship W2005371035A5047808099 @default.
- W2005371035 hasBestOaLocation W20053710351 @default.
- W2005371035 hasConcept C121332964 @default.
- W2005371035 hasConcept C1276947 @default.
- W2005371035 hasConcept C150846664 @default.
- W2005371035 hasConcept C41074950 @default.
- W2005371035 hasConcept C44870925 @default.
- W2005371035 hasConceptScore W2005371035C121332964 @default.
- W2005371035 hasConceptScore W2005371035C1276947 @default.
- W2005371035 hasConceptScore W2005371035C150846664 @default.
- W2005371035 hasConceptScore W2005371035C41074950 @default.
- W2005371035 hasConceptScore W2005371035C44870925 @default.
- W2005371035 hasIssue "3" @default.
- W2005371035 hasLocation W20053710351 @default.
- W2005371035 hasLocation W20053710352 @default.
- W2005371035 hasOpenAccess W2005371035 @default.
- W2005371035 hasPrimaryLocation W20053710351 @default.
- W2005371035 hasRelatedWork W1986109513 @default.
- W2005371035 hasRelatedWork W1989693711 @default.
- W2005371035 hasRelatedWork W1994702306 @default.
- W2005371035 hasRelatedWork W2029125027 @default.
- W2005371035 hasRelatedWork W2033821860 @default.
- W2005371035 hasRelatedWork W2103449991 @default.
- W2005371035 hasRelatedWork W2155757706 @default.
- W2005371035 hasRelatedWork W3104025681 @default.
- W2005371035 hasRelatedWork W3106428885 @default.
- W2005371035 hasRelatedWork W3121952711 @default.
- W2005371035 hasVolume "345" @default.
- W2005371035 isParatext "false" @default.
- W2005371035 isRetracted "false" @default.
- W2005371035 magId "2005371035" @default.
- W2005371035 workType "article" @default.