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The IAC catalog of ultracool dwarfs Optical and Near-infrared spectra

The IAC catalog of ultracool dwarfs Optical and Near-infrared spectra. http://www.iac.es/galeria/ege/catalogo_espectral. Eduardo Martin, Juan Cabrera, Elena Cenizo. 21 March 2007. Contents. ~900 M,L,T dwarfs XML and XSL 600 kb UDC running number,name,coordinates

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The IAC catalog of ultracool dwarfs Optical and Near-infrared spectra

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  1. The IAC catalog of ultracool dwarfs Optical and Near-infrared spectra http://www.iac.es/galeria/ege/catalogo_espectral Eduardo Martin, Juan Cabrera, Elena Cenizo 21 March 2007

  2. Contents • ~900 M,L,T dwarfs • XML and XSL 600 kb • UDC running number,name,coordinates • Photometry (V,R,I,J,H,K,L,M) • Vsini (km/s), Parallax (arcsec) • Spectral type, Halpha equivalent width • Link to spectrum (ascii or fits) • Wavelength range of spectrum (microns)

  3. Substellar evolution Stars Brown dwarfs Planets Coolest stars are early L dwarfs. Hottest brown dwarfs are late-M, and Hottest planets have L-type.

  4. Optical spectra of late-M and L dwarfs M9 L3 L5 L8

  5. Near-infrared spectra of L and T dwarfs L5 L7 L8 T1 T6

  6. Ultracool Atmospheres Abundances of important chemical species in substellar atmospheres Water vapour CO Methane Most of the O is in water vapour. Below 1100-2000 K, most C is in CH4. CO + 3H2 -> H2O + CH4

  7. Abundances of important chemical species in substellar atmospheres Chemical equilibrium

  8. Lithium in L dwarfs L1.5 L2 L2.5 L3.5 L5 L6 L6 L8

  9. Alkali elements in ultracool atmospheres Constant surface gravity. Constant Teff .

  10. Condensation and opacity due to dust TiO CrH FeH VO VO TiO TiO KI Chemical equilibrium. Condensation of TiO, VO, and CrH. Additional continuum opacity due to dust grains in the atmosphere.

  11. Settlement of dust grains L5 L6.5 L7 L8 T2 T5 T6 T8

  12. L and T quantitative spectral classification Methane in the J-band Steam in the J-band Steam in the H-band Methane in the H-band Steam in the K-band Methane in the K-band

  13. Effective temperatures and colors for L and T dwarfs

  14. Colors of ultracool dwarfs

  15. Beyond the T dwarfs: Y dwarfs H J I K R Teff = 500 K, solar metallicity model, log g = 4.0 (cgs). Dust has sunk to the bottom of the photosphere.

  16. References Atm Clas Atm Var HR Clas Clas Clas Atm HR Allard, et al. 2001, ApJ, 556, 357 Burgasser, et al. 2006, ApJ, 637, 1067 Burrows, et al. 2002, ApJ 573, 394 Clarke, et al. 2002, MNRAS, 332, 361 Dahn, et al. 2002, ApJ, 124, 1170 Kirkpatrick, et al. 1999, ApJ, 519, 802 Martín, et al. 1999, AJ, 118, 2466 McLean, et al. 2001, ApJ, 561, L115 Pavlenko, et al. 2000, A&A, 355, 245 Schweitzer, et al. 2002, ApJ, 566, 435 Atm: L and T atmospheres. Clas: spectral classification. HR: HR diagram (Teff, absolute magnitudes, colors). Var: variability.

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