1 / 38

Orbital motion of substellar companions

Orbital motion of substellar companions. Christian Ginski , Ralph Neuhäuser, Markus Mugrauer , Tobias Schmidt AIU Jena. „ Brown Dwarfs come of Age “ 22th May 2013. Background Image Credit : ESO/L. Calcada. Motivation.

les
Download Presentation

Orbital motion of substellar companions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Orbital motion of substellar companions Christian Ginski, Ralph Neuhäuser, Markus Mugrauer, Tobias Schmidt AIU Jena „Brown Dwarfs come of Age“ 22th May 2013 Background Image Credit:ESO/L. Calcada

  2. Motivation C. Ginski 2013 May 22th

  3. DetectionMethods

  4. DetectionMethods

  5. DetectionMethods

  6. DetectionMethods

  7. DetectionMethods Jupiter Saturn Neptune Uranus

  8. DetectionMethods young old

  9. DetectionMethods – Direct Imaging Confirmationof Companion Candidates: Multiple images in different observing epochs can be taken to confirm that the companion candidate is co-moving with the primary star. Photometry and spectra can be taken to confirm that the object is low-mass and of a similar age as the primary star. Problems: Observation campaigns target young associations in which all members exhibit similar proper motion Associationmembersexhibitsimilarage Detectionof orbital motionwouldsolvetheseproblems, i.e. wouldfinallyconfirmcompanionship + studyoforbitparametersmightgiveinsightto planet andbrowndwarfformation + determinationoftheorbitallowsdynamiccalculationofthe total systemmass

  10. ObservingEpochs and AstrometricMeasurements C. Ginski 2013 May 22th

  11. Observations – HD130948 VLT – NaCo NB 2.17 Caha 3.5m – ALFA: Ω-CASS H-Band N H-Band E N E Gemini North – Hokupa‘a/QUIRC Potter et al. 2002 Dupuy & Liu 2011: 0.1095 ± 0.0022 Mʘ

  12. Observations – GSC 08047 Neuhäuser et al. 2003 NTT – SHARPI N 2 arcsec E VLT – NaCo Ks-Band N E

  13. Observations Very Large Telescope, Chile Calar Alto Observatory, Spain

  14. Archive Data – HD130948 Gemini – NIRI Subaru – IRCS HST – ACS CH4 (short) H-Band F850 LP Gemini – Hokupa‘a/QuIRC H-Band N N N N E E E E

  15. Astrometric Calibration Binaries Cluster 47 Tuc VLT – NaCo Ks-Band HIP 73357 N E

  16. AstrometricResults – HD130948 VLT – NaCo NB 2.17 N E

  17. AstrometricResults – HD130948 N E

  18. AstrometricResults – HD130948 2.2 ± 3.7 mas/yr

  19. AstrometricResults – HD130948 0.16 ± 0.07 deg/yr

  20. AstrometricResults – GSC08047 6.3 ± 0.9 mas/yr

  21. AstrometricResults – GSC08047

  22. Orbit Fitting C. Ginski 2013 May 22th

  23. Least-Squares Monte-Carlo Method Implemented in Python SciPy (E. Jones, T. Oliphant , P. Peterson et al. 2001) - open-source software for mathematics, science, and engineering NumPy (D. Ascher et al. 1999) - fundamental package for scientific computing with Python Matplotlib (J. Hunter et al. 2007) - python 2D plotting library which produces publication quality figures

  24. Results - HD130948 Hill stabilitycriterionasgiven in Donnison et al. 2010

  25. Results - HD130948

  26. Results - HD130948

  27. Results - HD130948

  28. Results - HD130948

  29. Results - HD130948

  30. Results - GSC08047

  31. Results - GSC08047

  32. Conclusions C. Ginski 2013 May 22th

  33. Conclusions • Common proper motioncouldbeconfirmedforbothpresentedcompanions • orbital motion was detected but noorbitcurvatureyet • thedetectedorbitmotionisconsistentwithlowmassobjects on wideorbits • high eccentricitieswould fit scatterscenarios Astrometric Calibration of future measurements is vital for orbit determination !

  34. Further Work Small orbitcurvature was detected in thecaseofthe PZ Tel systemandtheorbitcouldbeconstrainedwellwiththe LSMC method. The system was not discussedherebecausethestudyisledby Dr. Markus Mugrauer. P = 110 yr Mugrauer, Röll, Ginski et al. 2012

  35. Thanksforyourattention !

  36. Additional Information

  37. LSMC vs MCMC

  38. Absolute Orbits GQ Lupby Neuhäuser et al. 2008 HD203030 byMetchev et al. 2006 CT Chaby Schmidt et al. 2008

More Related