FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2799058728> ?p ?o ?g. }

• W2799058728 endingPage "A19" @default.
• W2799058728 startingPage "A19" @default.
• W2799058728 abstract "In sunspot umbrae, convection is largely suppressed by the strong magnetic field. Previous measurements reported on negligible convective flows in umbral cores. Based on this, numerous studies have taken the umbra as zero reference to calculate Doppler velocities of the ambient active region. To clarify the amount of convective motion in the darkest part of umbrae, we directly measured Doppler velocities with an unprecedented accuracy and precision. We performed spectroscopic observations of sunspot umbrae with the Laser Absolute Reference Spectrograph (LARS) at the German Vacuum Tower Telescope. A laser frequency comb enabled the calibration of the high-resolution spectrograph and absolute wavelength positions. A thorough spectral calibration, including the measurement of the reference wavelength, yielded Doppler shifts of the spectral line Ti i 5713.9 {AA} with an uncertainty of around 5 m s-1. The measured Doppler shifts are a composition of umbral convection and magneto-acoustic waves. For the analysis of convective shifts, we temporally average each sequence to reduce the superimposed wave signal. Compared to convective blueshifts of up to -350 m s-1 in the quiet Sun, sunspot umbrae yield a strongly reduced convective blueshifts around -30 m s-1. {W}e find that the velocity in a sunspot umbra correlates significantly with the magnetic field strength, but also with the umbral temperature defining the depth of the titanium line. The vertical upward motion decreases with increasing field strength. Extrapolating the linear approximation to zero magnetic field reproduces the measured quiet Sun blueshift. Simply taking the sunspot umbra as a zero velocity reference for the calculation of photospheric Dopplergrams can imply a systematic velocity error." @default.
• W2799058728 created "2018-05-07" @default.
• W2799058728 creator A5000115308 @default.
• W2799058728 creator A5004840278 @default.
• W2799058728 creator A5006493901 @default.
• W2799058728 creator A5030233609 @default.
• W2799058728 creator A5033364971 @default.
• W2799058728 creator A5035452425 @default.
• W2799058728 date "2018-09-01" @default.
• W2799058728 modified "2023-10-10" @default.
• W2799058728 title "Absolute velocity measurements in sunspot umbrae" @default.
• W2799058728 cites W1510483402 @default.
• W2799058728 cites W1965635970 @default.
• W2799058728 cites W1977125661 @default.
• W2799058728 cites W1981195233 @default.
• W2799058728 cites W1984139711 @default.
• W2799058728 cites W1985505410 @default.
• W2799058728 cites W1993415900 @default.
• W2799058728 cites W1994418909 @default.
• W2799058728 cites W2003124783 @default.
• W2799058728 cites W2005825070 @default.
• W2799058728 cites W2008652390 @default.
• W2799058728 cites W2010659008 @default.
• W2799058728 cites W2015423371 @default.
• W2799058728 cites W2025015530 @default.
• W2799058728 cites W2029457318 @default.
• W2799058728 cites W2029643060 @default.
• W2799058728 cites W2034681035 @default.
• W2799058728 cites W2034807285 @default.
• W2799058728 cites W2049708180 @default.
• W2799058728 cites W2051148721 @default.
• W2799058728 cites W2052036336 @default.
• W2799058728 cites W2057770074 @default.
• W2799058728 cites W2062579310 @default.
• W2799058728 cites W2066620326 @default.
• W2799058728 cites W2067780101 @default.
• W2799058728 cites W2079067504 @default.
• W2799058728 cites W2089135799 @default.
• W2799058728 cites W2090103540 @default.
• W2799058728 cites W2094483427 @default.
• W2799058728 cites W2095221459 @default.
• W2799058728 cites W2097921125 @default.
• W2799058728 cites W2098479911 @default.
• W2799058728 cites W2119032654 @default.
• W2799058728 cites W2154260301 @default.
• W2799058728 cites W2154824150 @default.
• W2799058728 cites W2158612941 @default.
• W2799058728 cites W2161588005 @default.
• W2799058728 cites W2168745915 @default.
• W2799058728 cites W2171062718 @default.
• W2799058728 cites W2171752484 @default.
• W2799058728 cites W301151546 @default.
• W2799058728 cites W3098349814 @default.
• W2799058728 cites W3099085070 @default.
• W2799058728 cites W3099311451 @default.
• W2799058728 cites W3100789880 @default.
• W2799058728 cites W3105215486 @default.
• W2799058728 cites W4293763429 @default.
• W2799058728 cites W4301168978 @default.
• W2799058728 doi "https://doi.org/10.1051/0004-6361/201832886" @default.
• W2799058728 hasPublicationYear "2018" @default.
• W2799058728 type Work @default.
• W2799058728 sameAs 2799058728 @default.
• W2799058728 citedByCount "10" @default.
• W2799058728 countsByYear W27990587282019 @default.
• W2799058728 countsByYear W27990587282020 @default.
• W2799058728 countsByYear W27990587282021 @default.
• W2799058728 countsByYear W27990587282023 @default.
• W2799058728 crossrefType "journal-article" @default.
• W2799058728 hasAuthorship W2799058728A5000115308 @default.
• W2799058728 hasAuthorship W2799058728A5004840278 @default.
• W2799058728 hasAuthorship W2799058728A5006493901 @default.
• W2799058728 hasAuthorship W2799058728A5030233609 @default.
• W2799058728 hasAuthorship W2799058728A5033364971 @default.
• W2799058728 hasAuthorship W2799058728A5035452425 @default.
• W2799058728 hasBestOaLocation W27990587281 @default.
• W2799058728 hasConcept C10899652 @default.
• W2799058728 hasConcept C115260700 @default.
• W2799058728 hasConcept C120665830 @default.
• W2799058728 hasConcept C121332964 @default.
• W2799058728 hasConcept C1276947 @default.
• W2799058728 hasConcept C142757262 @default.
• W2799058728 hasConcept C151730666 @default.
• W2799058728 hasConcept C197370839 @default.
• W2799058728 hasConcept C198352243 @default.
• W2799058728 hasConcept C2524010 @default.
• W2799058728 hasConcept C2778861254 @default.
• W2799058728 hasConcept C2779343474 @default.
• W2799058728 hasConcept C33923547 @default.
• W2799058728 hasConcept C44870925 @default.
• W2799058728 hasConcept C4839761 @default.
• W2799058728 hasConcept C57879066 @default.
• W2799058728 hasConcept C62520636 @default.
• W2799058728 hasConcept C6260449 @default.
• W2799058728 hasConcept C86803240 @default.
• W2799058728 hasConceptScore W2799058728C10899652 @default.
• W2799058728 hasConceptScore W2799058728C115260700 @default.
• W2799058728 hasConceptScore W2799058728C120665830 @default.

• next