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BINARIES - Key to Comprehension of the Universe, Brno, Czech Republic, June 8-12, 2009 Selim O. SELAM Mesut YILMAZ Ankara University Observatory Hideyuki.

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Presentation on theme: "BINARIES - Key to Comprehension of the Universe, Brno, Czech Republic, June 8-12, 2009 Selim O. SELAM Mesut YILMAZ Ankara University Observatory Hideyuki."— Presentation transcript:

1 BINARIES - Key to Comprehension of the Universe, Brno, Czech Republic, June 8-12, 2009 Selim O. SELAM Mesut YILMAZ Ankara University Observatory Hideyuki IZUMIURA Okayama Astrophysical Observatory-NAOJ Ilfan BIKMAEV Kazan State University Bun’ei SATO Tokyo Institute of Technology Eiji KAMBE Okayama Astrophysical Observatory-NAOJ Varol KESKİN Ege University Observatory

2 ? ? ? ? ? ? ? ? ? ? ?? ? ?? ? ? ? ? ? ? ? ? ?? ? ? ??? ? ? ? ? ? ?? ? ???? ? ? ? ? ? ? ? ?? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ??

3

4 HD (F9 V) Latham et al., 1989, Nature, 339, 38 M sini = 11 M jup P orb = 84 days i = ? a Brown Dwarf ? Confirmed by Marcy in 1996 M sini = M jup P orb = days a = 0.35 AU  Cephei (K1 IVe + M4V) Campbell, Walker & Yang, 1988 ApJ, 331, 902 K =  25 m/s P orb = 2.7 years M sini = 1.7 M jup ? Orbital Phase V r (km/s) Confirmed by Hatzes et al., 2003, ApJ, 599, 1383 M sini = 1.7 M jup P orb = 2.48 years a = 2.13 AU Radial velocity (m/s) Years

5 PSR Wolszczan & Frail, 1992, Nature, 355, 145 M sini : 3.4 M  & 2.8 M  P orb : 66.6 days & 98.2 days a : 0.36 AU & 0.47 AU 3 th planet ?!

6 51 Peg b Mayor & Queloz 1995 Nature, 378, 355 M sini = 0.47 M jup P orb = days a = 0.05 AU G1 V 14.1 pc 70 Vir b Marcy & Butler 1996 ApJ, 464, L147 M sini = 6.6 M jup P orb = days a = 0.43 AU G2.5 V 17.8 pc 47 UMa b Butler & Marcy 1996 ApJ, 464, L153 M sini = 2.39 M jup P rot = 2.98 years a = 2.1 AU G0 V 5.1 pc

7 Doppler Technique Astrometry Planetary Transits Microlensing Direct Imaging Timing Polarimetry 322 (>90 % DT) by 1 st June Data from: Schneider J., 2009,

8 Data From: Schneider J., 2009,

9 DOPPLER TECHNIQUE  Jupiter12.4 m/sec  Saturn 2.7 m/sec  Earth 0.1 m/sec  Mercury 0.01 m/sec  Limitations in precision of measured radial velocities arise from spatial and temporal differences in the way of obtaining the stellar and reference spectra a) taken at different times b) taken over different optical paths c) flexture and thermal changes in the spectrometer  1 km/s

10 Griffin & Griffin, 1973 (MNRAS, 162, 243 and MNRAS, 162, 255) Telluric Lines ( Å)  m/sn

11 FT t P AoAo Monochromatic Light wave  1/P AoAo Delta Function  1/P AoAo Perfect Spectrograph  AoAo Real Spectrograph  1/P AoAo Instrumental Profile The instrumental profile produces a 2-4 pixel wide “BLURING” effect and can be represented with Gaussian profiles. INSTRUMENTAL PROFILE (IP)

12 There is no problem with the IP if it not chance its character with time stable symmetic IP stable asymmetic IP IP with time dependent character   V  V  V ~  m/s

13 DOPPLER TECHNIQUE A Thermally Stabilized Gas Absorption Cell in the front of the entrance slit of a spectrograph Iodine Cell ( I 2 ) gas filter Butler et al., 1996, PASP, 108, 500  3 m/s ! (Lick 3m)  1 m/s ! (Keck 10m) Overlays thousands of sharp I 2 lines between Å onto stellar spectrum

14 THE MODEL I( ): Observed “star+I 2 ” composite spectrum S( ): Intrinsic stellar spectrum  : Stellar Doppler shift A( ): “Transmission function of the I 2 Cell”- I 2 template IP : “Instrumental Profile” – produced by the 1D Point Spread Function of the detector k : normalization factor * : represents the convolution process made by FT DOPPLER TECHNIQUE (Butler et al., 1996, PASP, 108, 500 / Endl et al., 2000, A&Ap, 362, 585 / Takeda et al., 2002, PASJ, 54, 113 / Sato et al., 2002, PASJ, 54, 873) The observed stellar spectrum through an I 2 -cell I( ) is expressed as the product of intrinsic stellar spectrum S( ), and the transmission function of the I 2 -cell A( ) convolved with a modelled IP

15 THE MODEL DOPPLER TECHNIQUE The modeling process can be divided into the following three major steps (Endl et al., 2000): Step 1: Reconstruction of instrumental effects and spectrograph instrumental profiles by modeling pure iodine spectra using a high resolution Fourier Transform Spectrum (FTS) of the I 2 -cell. Transmission function of the I2-cell, A( ) is also obtained at this step. Step 2: Obtaining the “template” stellar spectra by deconvolving a pure star spectrum (taken without the I 2 -cell) with the IPs reconstructed in step 1. Step 3: Complete modeling of the star+I 2 spectrum. Transmission function of the I 2 -cell from step 1 and the deconvolved “template” stellar spectrum from step 2 serve as model templates, A( ) and S( ) to synthesize the observation. The Doppler shift between the iodine reference and the stellar absorption lines is determined with high accuracy. LICK Group Valenti et al., 1995, PASP, 107, 966 Butler et al., 1996, PASP, 108, 500 ESO Group Endl et al., 2000, A&Ap, 362, 585 OKAYAMA Group Takeda et al., 2002, PASJ, 54, 113 Sato et al., 2002, PASJ, 54, 873

16 Turkish National Observatory (TUG) RTT150 Telescope - CES Taurus Mountains-Bakirlitepe / Antalya, h=2500 m, 36º 49' 27“ N, 30º 20' 08“ E RTT150 Telescope Ø = 1.5 meters Coude f/48 Cassegrain f/7.7 Coude Echelle Spectrograph (CES) R =  / = slit width = 1.5 arcsec (500  m) 3800 – Å (85 orders) SAO-RAS 1Kx1K 16  m pix LN cooled F.I. CCD Registered wavelength interval on CCD 3900 – 8700 Å (68 orders)

17 To start exoplanet searches at Turkish National Observatory (TUG) we established an international collaboration between Turkish-Russian-Japanese colleagues An I 2 -Cell and its temperature controller was produced by our Japanese colleagues at Okayama Astrophysical Observatory (OAO) and successfully integrated to RTT150-CES on OCTOBER 2007 (for technical details, see : Kambe et al., 2002, PASJ, 54, 865)

18 First Ligth with new I 2 -Cell 26 October 2007

19 Test Observations 2007-II :TUG_RTT test 2008-I :TUG_RTT test 2008-II :TUG_RTT test + targets 2009-I :09A_RTT test + targets 44 allocated nights distributed within 1.5 YEARS Radial Velocity Standards and well known Planet-harboring Stars whose RV behaviors are well established within a few m/sn

20 Radial Velocity StandardsPlanet-harboring Stars iot Per tau Cet

21 ACHIEVED RV PRECISION For V=3 mag stars under ~15 min. exposure time (S/N=200) m/s For V=6.5 mag stars under  30 min. exposure time (S/N=100) ~25 m/s TARGET STARS OF OUR PROJECT 50 G-type giants showing RMS>25 m/s RV variation in previous RV surveys slow rotators, many sharp absorption lines relatively stable against pulsations relatively low surface activity


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