1 / 13

Spectral Analysis Cycle for Stellar Variability Study

Overview of methodology and tasks for analyzing stellar spectra to detect variability, determine radial velocity and vsini for different types of stars. Includes methods, observations, and improvement cycles.

jerome
Download Presentation

Spectral Analysis Cycle for Stellar Variability Study

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. Meeting GHOST2 Participation in CU6 13-14/11/2006 LAM

  2. Overview • Different deadlines depending on the state of the workpackages • rv, Vsini for all types of stars: cold to hot stars • General information on spectra • rv, Vsini on component of multiple system • Detection of the variability

  3. Algos…

  4. Algo, Single transit analysis

  5. Single transit analysisCoarse characterization of sourcesS650-06000 C.Martayan, A.-M. Hubert • Lists of abs/Em lines (common with CU8) • Give S/N ratios • Give slopes of spectra • Determine RVS magnitudes, comparisons RVS vs spectro-photométrie and vs ground-based photometry • Use templates/masks for lines and cross-correlation

  6. Single transit analysisCoarse characterization of sources • Other tasks to add ? • Cycle 2: 10/2006-05/2007 • Define methods • Specification of requirements • Obtaining observed and synthetic spectra • Cycle 3: 05/2007-11/2007 • Define and write algorithms • Observations • Tests with observed and synthetic spectra • Improvement of methods/algo.

  7. Algos…

  8. Single transit analysisrv & Vsini in Fourier spaceS650-08000/09000 Y. Frémat, A. Lobel, C. Delle-Luche, S. Jankov • rv, use of cross-correlation in Fourier space • Functional analysis done • Fortran prototype good results: • Cold to hot stars • Vsini=0, rv=20 <rv>:19.75-19.84 for V:6-14 • Vsini=150, rv=20 <rv>:18.94-19.27 for V:6-14

  9. Single transit analysisrv & Vsini in Fourier spaceS650-08000/09000 Y. Frémat, A. Lobel, C. Delle-Luche, S. Jankov • Cycle 2: • delivery soft requirements, • soft design, • end of fortran prototype, implementation of java algo. • Tests of java algo, delivery soft products • Validation of soft • Cycle 3: beginning of Vsini study

  10. Single transit analysisrv & Vsini by mini distance methodS650-10000 R. Blomme, A. Lobel • Input: grids of template spectra Teff, logg (provided by CU8) • Method defined • Algo try broadening function, rv shift, best fit • Other method: Least Square Deconvolution • Cycle 2: implementation 1st solution direct in java • Cycle 3: implementation 2nd solution

  11. Algos… & multiple transits analysis

  12. Multiple transits analysisRV & Vsini for multiple line systemsS660-04000 E. Gosset, G. Rauw, Y. Nazé • Using TODCOR method: 2D cross-correlation with 2 templates of spectra • Ratio of flux pre-defined or fitted • Cycle2: flux ratio fixed, test data to be computed • Problems of parameters difficult in case of multiple lines • Provide a flag to indicate the multiplicity • Recruitment of 1 postdoc

  13. Multiple transits analysisAssess source variabilityS660-06000 P. De Cat, L. Eyer, A.-M. Hubert, S. Jankov, P. Dubath, S. Udry • Drv as function of type of variable • Detection of the variability in CU6 (CU7 analyses) • Function of the S/N ratio • Statistical tests (low S/N) • Cross-correlation peak (intermediate S/N) • Line profile variation, study of Em lines (good S/N) • Cycle2: analysis on low S/N ratio, statistical tests on rv distributions, prototypes will be developed • Cycle3: request for simulated data

More Related