the sdss-iii marvels survey: overview and first results nathan de lee and the marvels team
TRANSCRIPT
De Lee, Shanghai 2009
MARVELS TEAM
Principal investigator: Jian Ge (UF)
Survey scientist: Holland Ford (JHU)
Project manager: Fred Hearty (UF)
Instrument scientist: Xiaoke Wan (UF)
SWG chair: Eric Agol (UW)
Data coordinator: Brian Lee (UF)
MARVELS SWG Members: E. Agol, E. Ford, H. Ford, S. Gaudi, D. Schneider, J. Holtzman & S. Seager
UF Staff and Postdocs: X. Wan, S. Mahadevan, B. Lee, B. Zhao, J. Groot, F. Hearty, K. Hanna, F. Varosi, J. van Eyken, S. Kane (UF and IPAC), L. Chang, Z. Chen, J. Liu, C. Murphey, S. Thirupathi, &
N. De Lee
UF Grads and Undergrads: S. Fleming, P. Guo, P. Jiang, M. Malik, A. Shelden, J. Crepp, J. Wang, A. Fletcher, P. Rohan, E. Costello, & S. McDowell
Other collaborators: D. Eisenstein, D. Weinberg, J. Gunn, F. Leger, P. Harding, M. Blanton, J. E. Martin, Bochanski, A. Wolczczan, A. Niedzielski, D. Montes, S. Hawley, D. Schlegel, & S. Snedden
De Lee, Shanghai 2009
SDSS-III
Since September 2008, SDSS III has been using the wide field Sloan 2.5m Telescope for up to 4 projects: All using massive fiber-fed spectroscopic surveys
• BOSS: A Baryon Oscillation Survey with a 1000 fiber spectrograph
• APOGEE: A NIR H band R~20k spectrograph to look at K giants
• SEGUE-2: Galactic Dynamics using current SDSS spectrographs
• MARVELS: Multi-Object APO Radial Velocity Exoplanet Large Area Survey
De Lee, Shanghai 2009
MARVELS Overview
• Monitor a total of 10,000 V=7.6-12 FGK dwarfs and subgiants
• Monitor a total of 1,000 V=7.6-10 G and K giants
• Both groups will be selected with minimal metallicity and age biases for detecting and characterizing ~200 giant planets.
• Use all of the bright time in 2008-2011 and share the bright time with APOGEE in 2011-2014
• Approx. 120 fields will be monitored about 30 times over ~18 months
• Up to two multi-object Doppler instruments with a total of 120+ object capability
• The wavelength coverage ~ 500-570 nm
• Spectral resolution ~10,000
De Lee, Shanghai 2009
MARVELS Science Goals
To find a homogeneous sample of several hundreds of giant planets that can be used for statistical study of planet properties and comparison to theory
Constrain formation, migration & dynamical evolution of planetary systems
Discovery of rare systems (e.g. “Very Hot Jupiters”, short-period super-massive planets, short-period eccentric planets, transiting planets, highly eccentric planets, rapidly interacting multiple planet systems, planets orbiting low-metallicitiy host stars, planets around active and young stars, and other rare types of planets)
Find signposts for lower-mass or more distant planets
Quantify the brown dwarf desert
De Lee, Shanghai 2009
MARVELS Field Selection
Survey area is ~800 sq deg, a total of ~120 fields, mainly along the Galactic plane
About 80 fields will be shared with APOGEE in 2011-2014
Field selection is based on sufficient number of bright observable stars in each field, and some fields need to have known calibrators for initial instrument calibration
64 fields, including some calibration fields, have been selected for the first two years of operation
A number of fields have also been selected to coincide with the one of the 21 CCD modules of the KEPLER space mission
De Lee, Shanghai 2009
Preselection Targets
• Targets initially selected from GSC2.3 catalog matched up with 2MASS for J, H, K colors
• SDSS spectroscopy pre-selection efficiently remove giants (e.g., log g < 3.0) and stars that are too hot (e.g., Teff > 6250 K) from the
initially color selected targets• 25-35% of the ~500 candidates
per field are acceptable targets Effective temperature and gravity plot
of target candidates of 7 fields
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Final Distribution of Targets
Final distributions based on 41 of the 60 first season fields
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Current Survey Status
Number of Survey Observations: 489
Number of Plates Observed: 43
Total Number of stars: 2580
De Lee, Shanghai 2009
Current Error Estimates
RMS errors based on current pipeline from the Instrument Acceptance Review.
De Lee, Shanghai 2009
Reference Star Fits
HD 68988 V=8.21, G0, 1.9 MJ, P=6.276
days, e=0.14 (Vogt et al. 2002)
HIP 14810bV=8.52, G5, 3.84 MJ, P=6.67
days, e=0.15 (Butler et al. 2006)
De Lee, Shanghai 2009
Brown Dwarf Candidate
More information will be available in Lee et al. 2009 in preparation
De Lee, Shanghai 2009
MARVELS Pipeline Development
To help reduce systematics in the MARVELS data, a number of avenues are being looked at:– PV Scale correction– Cosmic ray rejection– Distortion correction– Low flux spectra
Dispersion direction
De Lee, Shanghai 2009
Summary and Future Work
The MARVELS instrument is producing radial velocity data in survey mode.
Continue work on the MARVELS Pipeline Look into methods to increase throughput Work on hardware upgrades / repairs Develop large scale RV fitting procedures Further the groundwork for the second instrument. Follow-up current candidates