Pulsations and magnetic activity in the IR Rafa Garrido & Pedro J. Amado Instituto de Astrofsica de Andaluca, CSIC. Granada Acoustic oscillations p ( r, , , t ) p
Angular dependence (l,m) f nlm (r) Y lm( , ) e i n,l t n,l,m Radial dependence (n) Standard solar model
1996 standard solar model inclusion of He settling & improved physics base of convection zone better physics for core needed Standard solar model
Differential rotation Small and large separations Solar oscillations (VIRGO-SOHO) Asteroseismic diagram: J. C. Christensen-Daslgaard, Rev. Mod. Phys., 74, 1073 Variability Zoo Scuti Doradus
Giants UMa Hya GSC 09137- 03505 Boo LAST RESULTS WITH HARPS B. Mosser (Corot week 6: May 2004, Orsay) A clear signature of the large separation : 89 Hz
HARPS PERFORMANCE 2 minutes integration time for V=6 on the ESO 3.6m: v=1 ms-1 @ vsini= 0 kms-1 v=3 ms-1 @ vsini=10 kms-1 RV S 0.5 0.5
R 1.5 Benefits from the IR Flux gain Benefits from the IR magnetic sensitivity
Problems Theory mode selection (amplitudes) amplitude & phase changes input physics in models
convection & overshooting diffusion & settling rotation magnetic field Observations
mode identification (spectroscopy & photometry) data analysis Dynamo Active stars: Science goals geometry Solar-like
or something different? Polar spots and active belts Spot structure Resolved or not? Differential
rotation and meridional flows Lifetimes of individual spots and active regions Stellar butterfly diagrams Different stellar types Pre-main sequence stars Young main-sequence stars with[out] radiative interiors Subgiants and giants Doppler Imaging A
A Intensity -v sin i Intensity v(spot) v sin i
-v sin i v(spot) v sin i Data requirements Time-series Good of hi-res (R > 30000) spectra:
supply of unblended intermediate-strength lines (!) Broad-band light-curves. TiO and other temperature diagnostics. Least-Square Deconvolution Assume observed spectrum = mean profile convolved with depth-weighted line pattern: Depth-weighted line pattern, - KNOWN Mean profile, z
(UNKNOWN) = Rotationally broadened spectrum, r KNOWN De-convolve mean profile zk via least squares: r j jk z k
2 Solve : 0, where 2 zk j j 2 2
S/N improves from ~100 to ~2500 per 3 km s1 pixel with ~2500 lines. DI Maps AB Dor DI Maps VW Cep ZDI Maps
AB Dor Benefits from the IR Spectral lines are less blended in the infrared. Hence, line profile variations are more clearly detected The Zeeman effect is enhanced for lines in the IR 2 Radiation flux and pulsation amplitudes increase with increasing wavelength for cooler stars. IR lines can probe different parts of the atmosphere.
Benefits from the IR Sun continuum contrast between photosphere and Tspot = 4250 K: 20% @ 0.6 m 70% @ 2.2 m
Resolving the telluric absorption lines (intrinsically narrow ~5 km s1) Pontoppidan & van Dishoeck, 2004, astroph 0405629 Zeeman sensitivity: the Fe I line at 1.56 m splits by twice the FWHM in 1.5 kG fields (slowly rotating stars): 2-3 times more sensitive than optical lines (Giampapa PASP 109)
MasterCard International Credit Card Security & Risk IS6800 Group Presentation Mike Cornish Kathleen Delpha Mary Erslon November 2004 Agenda MasterCard Organization Credit Card 101 Credit Card Fraud Case Studies Card Not Present Fraud Identity Theft Fraud Best Practices for Credit...
Unit 5 VCB, Level F Unit 5 Vocabulary Unit 5 -First 10 Words Amnesty Caveat Extricate Filch Flout Fractious Precepts Sepulchral Unwieldy Vapid Amnesty (n) A general pardon for an offense against a government; in general, an act of forgiveness...
802.16 - WiMAX and WMAN: Opportunity or Threat? Seamless Mobility . The Integration of Wi-Fi and WiMAX in HFC. Live . Learning. TM. Archives. SCTE Live Learning Webinar. Definition: One-hour technical web-based seminar, typically a "cutting edge" topic. SCTE LiveLearning...
What is each member's responsibility? Short progress reports are required Project Signup (1/2) Project Signup: Watch "Group/Section Signup" Link 4-5 members to a group Everyone in group must be able to actually attend same section The sections assigned to you...
review the Quartus II Software Release Notes and the SOPC Builder to Qsys Migration Application Note for known issues and limitations. ... Download latest Quartus II Software and get a Qsys productivity boost in your system design today! References. System...
The unique loop design provides 360° apposition and dynamic sizing in the 3.5 to 5.5 mm range. Emily STOP Heather Start During the procedure, a small flexible catheter with a metallic stent and a small filter device (umbrella-like) placed at...