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Titolo:
Infrared spectra and spectral energy distributions of late M and L dwarfs
Autore:
Leggett, SK; Allard, F; Geballe, TR; Hauschildt, PH; Schweitzer, A;
Indirizzi:
Joint Astron Ctr, Hilo, HI 96720 USA Joint Astron Ctr Hilo HI USA 96720Joint Astron Ctr, Hilo, HI 96720 USA Ecole Normale Super Lyon, CRAL, F-69364 Lyon, France Ecole Normale Super Lyon Lyon France F-69364 CRAL, F-69364 Lyon, France Gemini Observ, Hilo, HI 96720 USA Gemini Observ Hilo HI USA 96720Gemini Observ, Hilo, HI 96720 USA Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA Univ Georgia Athens GA USA 30602 Dept Phys & Astron, Athens, GA 30602 USA Univ Georgia, Ctr Simulat Phys, Athens, GA 30602 USA Univ Georgia Athens GA USA 30602 , Ctr Simulat Phys, Athens, GA 30602 USA
Titolo Testata:
ASTROPHYSICAL JOURNAL
fascicolo: 2, volume: 548, anno: 2001,
parte:, 1
pagine: 908 - 918
SICI:
0004-637X(20010220)548:2<908:ISASED>2.0.ZU;2-4
Fonte:
ISI
Lingua:
ENG
Soggetto:
BROWN DWARFS; ABSORPTION-LINES; STARS; DENIS; ATMOSPHERES; LUMINOSITY; METHANE;
Keywords:
infrared : stars; stars : fundamental parameters; stars : late-type; stars : low-mass; brown dwarfs;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
46
Recensione:
Indirizzi per estratti:
Indirizzo: Leggett, SK Joint Astron Ctr, Univ Pk, Hilo, HI 96720 USA Joint Astron CtrUniv Pk Hilo HI USA 96720 Hilo, HI 96720 USA
Citazione:
S.K. Leggett et al., "Infrared spectra and spectral energy distributions of late M and L dwarfs", ASTROPHYS J, 548(2), 2001, pp. 908-918

Abstract

We have obtained 1.0-2.5 km spectra at R similar to 600 of 14 disk dwarfs with spectral types M6-L7. For four of the dwarfs, we have also obtained infrared spectra at R similar to 3000 in several narrow intervals. In addition, we present new L' photometry for four of the dwarfs in the sample, whichallows improved determinations of their bolometric luminosities. While obtaining the photometry we resolved the L dwarf Denis-P J0205-1159 into an identical pair of objects separated by The spectra together with the 0."35. published energy distribution for one other L5 dwarf are compared to synthetic spectra generated by upgraded model atmospheres. Good matches are found for 2200 K greater than or equal to T-eff greater than or equal to 1900 K (spectral types around M9-L3), but discrepancies exist at T-eff greater thanor equal to 2300 K (M8) and T-eff less than or equal to 1800 K (L4-L7). Atthe higher temperatures the mismatches are due to incompleteness in the water vapor opacity line list. At the lower temperatures the disagreement is probably due to our treatment of dust; we assume a photospheric distribution in equilibrium with the gas phase and neglect any diffusion mechanisms. We derive effective temperatures for the sample from the comparison with synthetic spectra and also by comparing our observed total intrinsic luminosities to structural model calculations (which are mostly independent of the atmosphere but are dependent on the unknown masses and ages of the targets). The two derivations agree to about 200 K except for the faintest object inthe sample, where the discrepancy is larger. Agreement with other temperature determinations is also +/- similar to 200 K, except for the L7 dwarf.

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Documento generato il 25/05/18 alle ore 09:01:13