P4-1 Precision Radial Velocity Spectrometer (PRVS) 2nd generation (“Aspen”) instrument for...
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Transcript of P4-1 Precision Radial Velocity Spectrometer (PRVS) 2nd generation (“Aspen”) instrument for...
P4-1 Precision Radial Velocity Spectrometer (PRVS)
• 2nd generation (“Aspen”) instrument for Gemini• R=70,000, 1.0-1.8 m, RV stability < 1 m/s• Goal: Find terrestrial (HZ) planets around M dwarfs.
H. Jones (Hertfordshire), J. Rayner (Hawaii), L. Ramsey (PSU), B. Dent (UK ATC), A. Longmore (UK ATC), B. Vacca (Hawaii), M. Liu (Hawaii), A Webster (UK ATC), A. Wolscznan (PSU), et al.
4. TRACEBILITY2. IMPACT ON THE DISK
3. CIII] emissivity (stellar 1kG dipolar field)
Stellar Wind
Episodic Plasmoids Ejection
Disk Wind
Disk dynamo in action No disk dynamo
1. THE BASICS
Gómez de Castro & von Rekowski, 2007
z-axis
r-axis
z-axis
Propagation of 2MeV electrons in the inner
border of the disk
DiskMidplane
•Most of the energy is releasead along the incidence direction within a beam of 2 107 cmand a depth of 8 107cm (disk height 109 cm)
•Energy spreading has to be done through the Hard Bremsstrahlung radiation energy cascade. Selective absorption by disk molecules produces PDRs
•A non-negligible source of ionization further than the atmosphere.
•A source of high energy electrons to interact with molecules collisionally
Gómez de Castro & Antonicci, 2007
1993 2001
Optically thin lines emitted by the plasma
@Tє[3000-300,000]K -> UV wavelengths
Tracing the interaction of the stellar wind with the
young planetary disk material
Detecting the output from accretion and outflow
(densities and temperatures are similar)RY Tau: Gómez de Castro & Verdugo, 2007,ApJL
AB Dor: Gómez de Castro 2002
A Clear Signature of Star-Disk Interaction in NGC 2264 and the Orion Nebula Cluster
P4-4 Cieza & Baliber
ORION
NGC 2264 ONC
MC MODEL
A Search for Disk-Locking in Chamaeleon I and Taurus-AurigaA Search for Disk-Locking in Chamaeleon I and Taurus-AurigaD. C. Nguyen, R. Jayawardhana, M. H. van Kerkwijk, A. Brandeker, A. Scholz
University of Toronto
D. C. Nguyen, R. Jayawardhana, M. H. van Kerkwijk, A. Brandeker, A. Scholz
University of Toronto
Cha I Tau-Aur
1. Accretors and non-accretors are clearly delineated by H 10% width2. Preliminary results show a smaller fraction of fast rotators that are accreting than not
accreting in both samples3. Our sample has smaller fraction of fast rotators than Orion Molecular Cloud population
sampled by Rebull et al. (2006, ApJ, 646, 297)
1. Accretors and non-accretors are clearly delineated by H 10% width2. Preliminary results show a smaller fraction of fast rotators that are accreting than not
accreting in both samples3. Our sample has smaller fraction of fast rotators than Orion Molecular Cloud population
sampled by Rebull et al. (2006, ApJ, 646, 297)
Spitzer Observations of h & Persei: Protoplanetary Disk Evolution & Planet Formation at 10-15 Myr
• stellar mass-dependent evolution of disks
• λ – dependent evolution of disks
• Terrestrial-Zone Debris Disks
T. Currie, et al. 2007, ApJ, 659, 599
Poster P4-6
Imaging survey of optically visible Herbig stars from Gemini North & South (12 m & 18 m)
Mid-IR extended emission is resolved in 10/20 sources with sizes 100 to 500 AU
There is an additional compact unresolved component in all sources
•8 sources resolved @ FWHM &
lower brightness level
•2 sources resolved @ lower brightness level
•9 sources unresolved
Exploring the Geometry of Protoplanetary Disks in the Mid-Infrared
Mariñas, N., Telesco, C.M., Packham, C., and Fisher, R.S.
Compact sources => younger, more massive, higher mass accretion rates!
(Proposed evolution of disks by Dullemond & Dominik 2004)
• Our study: image thermally-emitting dust in nearby (<100 pc) debris disk candidates (identified by Spitzer/MIPS photometry) with subarcsecond resolution
• Observing program of 20 sources at 10 & 18 microns at Gemini is near completion
• 2 sources spatially resolved so far: Zeta Lep & HD 32297
P4-9Moerchen et al.
P4-11
A Search for Warm Dust in the Habitable Zones Around Solar-like Stars David Ciardi, Samantha Lawler, Chas Beichman, Rachel Akeson (Michelson Science Center/Caltech)
Geoff Bryden, Karl Stapelfeldt, Angelle Tanner (Jet Propulsion Laboratory)
Goals
• Survey 152 FGK(M) stars for warm dust
• Spitzer IRS SL (7 – 14 m) & LL (14 – 35 m)
• Are there more stars like HD 69830 ???
Summary of Results
• 19/152 (13%) have IRS excess (87% no excess)
• All excesses at > 14 m
• No spectral features observed (large grains)
• If a star has an IRS excess & 70 m data, then the star also has 70 m excess
• 5 stars with 70 m have NO IRS excess
Lisse et al. 2006