2007/01/13 by A. K. Mainzer, A. Mainzer, Thomas L. Roellig +7 · 3 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Infrared #Infrared spectroscopy #Physics #Spectral line #Spectral resolution #Spectrograph #Spectroscopy #Spitzer Space Telescope #Stellar, planetary, and galactic studies #Telescope #astro-ph
paper · pdf · doi:10.1086/516561
published as Astrophys.J.662:1245-1253,2007 · 19 pages, 7 figures, accepted ApJ 1/12/07
arxiv created 2007/01/13 · openalex publication_date 2007/06/12 · arxiv updated 2011/02/11 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present 10-19 μm moderate-resolution spectra of 10 M dwarfs, one L dwarf, and two T dwarf systems obtained with the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope . The IRS allows us to examine molecular spectroscopic features/lines at moderate spectral resolution in a heretofore untapped wavelength regime. These R = λ/Δλ ~ 600 spectra allow for a more detailed examination of clouds and nonequilibrium chemistry, as well as the molecular features of H 2 O, NH 3 , and other trace molecular species that are the hallmarks of these objects. A cloud-free model best fits our mid-infrared spectrum of the T1 dwarf Indi Ba, and we find that the NH 3 feature in Indi Bb is best explained by a nonequilibrium abundance due to vertical transport in its atmosphere. We examined a set of objects (mostly M dwarfs) in multiple systems to look for evidence of emission features, which might indicate an atmospheric temperature inversion, as well as trace molecular species; however, we found no evidence of either.