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Cool Stars 13, Hamburg 2004 FUSE Spectroscopy of Cool Stars Graham Harper CASA, University of Colorado
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Cool Stars 13, Hamburg 2004 Far Ultraviolet Spectroscopic Explorer FUSE USA with France and Canada as partners FUSE Launched June 24, 1999. 765 km circular orbit, inclined 25 degrees, P = 100 minutes. 5-yr in orbit 3-yr Primary Mission ended Mar. 2003. Now all Guest Investigator (GI). Approx. 9 Msec/yr of science observations; ~ 600 objects/yr. 30% orbital efficiency for science observations
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Cool Stars 13, Hamburg 2004 Far Ultraviolet Spectroscopic Explorer 905Å < λ < 1187Å Resolution ~ 15 kms -1 Three Apertures LWRS 30x30" MDRS 4x20" HIRS 1.25x20" Pointing ~ 0.5" FWHM ~ 1" @ 1000Å
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Cool Stars 13, Hamburg 2004 FUV Spectral Diagnostics
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Cool Stars 13, Hamburg 2004 α TrA Hybrid chromosphere star
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Luminous Cool Stars A. Dupree kindly provided a figure from the Cool star PI team – from a paper in progress (not shown here) Fig. showed how the spectra are typically a combination of solar-like transition region lines and Fe II fluorescence Fig. showed discovery of O VI (a coronal proxy) in α Tau, and the Fe XVIII emission
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Cool Stars 13, Hamburg 2004 Hyades F dwarfs – touching the corona? Böhm-Vitense, Robinson, & Carpenter (2004 ApJ 606, 1174) Determine whether 300000 K plasma is heated by conduction from corona or the same heating that controls lower T e O VI & CIII 977Å compared with IUE/HST and ROSAT B-V and vsini trends for O VI very different from X-rays Conclude heating Te < 300,000 K not dominated by conduction from corona
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Cool Stars 13, Hamburg 2004 Convective/Radiative Boundary Simon et al. (2002 ApJ 579, 800) Search for FUV emission in A stars Follow up of ORFEUS-SPAS II α Cephei (A7 V)
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Cool Stars 13, Hamburg 2004 Convective/Radiative Boundary
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Cool Stars 13, Hamburg 2004 Convective/Radiative Boundary
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Cool Stars 13, Hamburg 2004 Convective/Radiative Boundary Simon et al. (2002 ApJ 579, 800) Search for FUV emission in A stars Teff < 8200 K: solar-like normalized fluxes Teff > 8300 K: non-detections <1/40 th solar Transition from convective to radiative envelope occurs near 8250 K in agreement with structure models
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A-F Supergiants: Blue loop activity A. Brown provided a figure showing the OVI region for a sample of A-F supergiants. These stars are consistent with blue-loop activity. B. The OVI is clearly detected in the A8 Ib star C. This work will be presented at the D. “Astrophysics in the Far Ultraviolet” Five Years of Discovery with FUSE – Victoria, BC August 2-6, 2004
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Cool Stars 13, Hamburg 2004 Electron Pressure/Opacity Diagnostics
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C III Electron Pressure Diagnostics Do not abandon hope! Samples of disk integrated fluxes CIII 1175/977Å Guinan et al. (2003 ApJ 594, 561) Sun-in-Time – snap-shots of Pe Combine DEM or proxy Ionization balance 1175.98Å relative to Σ1175Å
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Optical Depth Effects 1175Å AU Mic Bloomfield et al. (2002 A&A 390, 219) 1175.71Å & 1174.94Å share common upper-level J=2 Ratio changes during flare Low gravity stars: opacity effects play a larger role
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Cool Stars 13, Hamburg 2004 FUV Coronal Forbidden Lines Feldman et al. (2000 ApJ 544, 508) HST Fe XXI 1354Å Blended with C I HST Fe XII 1242,1349Å Jordan et al. (2001 MNRAS 322, L5) Redfield et al. (2003 ApJ 585, 993) FUSE Fe XVIII 974Å (clean) FUSE Fe XIX 1118Å (blend C I) Thermally broadened lines Plasma is not part of the wind
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Cool Stars 13, Hamburg 2004 Fe XVIII & Fe XIV
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Cool Stars 13, Hamburg 2004 Extended Coronal Rotation? Excess broadening Beyond thermal + vsini Consistent ΔR~0.4-1.3R ∗ OR excess turbulence
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Cool Stars 13, Hamburg 2004 Fluorescence Probe of intrinsic HI Lyα profile Before attenuation by ISM Before attenuation by wind FUSE & HST Fe II H 2
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Cool Stars 13, Hamburg 2004 Fluorescence: HLyα & Fe II
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Cool Stars 13, Hamburg 2004 Fluorescence: Mira B - HLyα & H 2 Mira A&B- Wood & Karovska (2004 ApJ 601 502) HST Lyman band lines FUSE reveals Werner band lines
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Cool Stars 13, Hamburg 2004 Fluorescence: Mira B - HLyα & H 2
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Cool Stars 13, Hamburg 2004 Fluorescence: Mira B - HLyα & H 2 Mira A&B - Wood & Karovska (2004 ApJ 601 502) HST Lyman band lines FUSE reveals Werner band lines Reconstructed Lyα T=3900 K & LogN(H 2 )=17.1 Photodissociation front Mira B H Lyα interacts Mira A’s wind
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Cool Stars 13, Hamburg 2004 FUSE Status Gyroless software installed and tested July 2003 worked seamlessly – no loss of science 4 operational gyros – currently in 2 gyro mode Allow for fast response of TOO CalFUSE v3.0.7: public release 15 th July 2004 New photon list data structure Allows for more efficient screening of data 2 reaction wheels + magnetic torquer bar Sky availability recently expanded Cycle 6 proposal deadline Sept 17 th 2004
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Cool Stars 13, Hamburg 2004 That’s All Folks … Other CS13 FUSE Presentations Talks Cian Crowley – Wind Velocity Laws of Symbiotics Posters Thomas Ake – Eclipsing Binaries Brian Espey – Mass Loss from Symbiotics
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Cool Stars 13, Hamburg 2004 Pre-mainsequence & Protoplanetary Systems T Tauri TW Hya - Herczeg et al. (2004 ApJ 607, 369) Herbig AeBe HD 104237 - Grady et al. (2004 ApJ 608, 809) Lecavelier des Etangs et al. (2003 A&A 407, 935) HD 100546 - Deleuil et al. (2004 A&A 418, 577) βPic systems Bouret et al. (2002 A&A 390, 1049)
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Cool Stars 13, Hamburg 2004 Thanks to George Sonneborn: FUSE Project Scientist Bill Blair: FUSE Chief of Observatory Operations All and Sundry for discussions and kindly providing figures
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