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Published byRichard Daniel Modified over 9 years ago
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1 * Pulsar V=5-50 AU/yr CNM How do we observe AU-scale structure? Pulsars, and optical depth imaging against extended radio continuum sources…. Epoch 1Epoch 2
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2 Equivalent width variations EW = 0 within 2 for: 0823, 1133,1737, 2016 EW 0 for 1929 TSAS: L=5-50AU, n~10 4 cm -4, P~10 6 cm -3 K Stanimirovic, Weisberg et al. (2010)
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3 PSR at ~330pc * Welsh et al. (2010) Distance=350 pc, closest in the sample ½ of LOS inside the Local Bubble. HD178125 and HD180555 show NaI absorption as similar velocity TSAS is within the LB! LOS to B1929+10 pierces the LB wall for 50-60 pc. Many diffuse clouds in this direction (Aquila Rift) condensing out of the LB wall or ablated nearby molecular gas TSAS Tspin = 150-200 K CNM/WNM ratio = only 7% TSAS properties/production influenced by the history/evolution of the Local Bubble What’s going on with B1929+10 ?
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4 With different sources, essentially continuous coverage. No observed power-law turbulent spectrum on scales: 1 to ~1000 AU. Kendall’s tau test for censored data: P(no correlation) ~60% Inhomogeneity in Galactic distribution of TSAS + v.f.f.<~1% TSAS is not pervasive. If TSAS is tracing the end-scales of turbulence then turbulence may dissipate in bursts or active pockets, or it dissipates very fast. Does the power spectrum extend down to AU- scales? Low optical depth High optical depth * : interferometric other: pulsars
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5 With different sources, essentially continuous coverage. No observed power-law turbulent spectrum on scales: 1 to ~1000 AU. Kendall’s tau test for censored data: P(no correlation) ~60% Inhomogeneity in Galactic distribution of TSAS + v.f.f.<~1% TSAS is not pervasive. If TSAS is tracing the end-scales of turbulence then turbulence may dissipate in bursts or active pockets, or it dissipates very fast. Does the power spectrum extend down to AU- scales? * : interferometric other: pulsars
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