COBE Far Infrared Absolute Spectrophotometer Observations of Galactic Lines
1999; IOP Publishing; Volume: 526; Issue: 1 Linguagem: Inglês
10.1086/307962
ISSN1538-4357
AutoresD. J. Fixsen, C. L. Bennett, John C. Mather,
Tópico(s)Atmospheric Ozone and Climate
ResumoThe COBE Far Infrared Absolute Spectrophotometer (FIRAS) observations constitute an unbiased survey over the wavelength range from 100 μm to 1 cm over 99% of the sky. Improved calibration of the FIRAS instrument and the inclusion of all of the FIRAS data allow an improved signal-to-noise ratio determination of the spectral lines by a factor of ~2 over our previous results. The resolution is low (0.45 cm-1), so only the strongest lines are observable. The CO chain from J = 1-0 to J = 8-7 is observed toward the Galactic center. The line ratios are roughly consistent with a 40 K excitation temperature. The 157.7 μm C II and 205.3 μm N II lines are observable over most of the sky. The 370.4 and 609.1 μm lines of C I and the 121.9 μm line of N II are observed in the Galactic plane. The line ratios at the Galactic center are consistent with a density of n0 ~ 30 cm-3 and a UV flux of G0 ≈ 15 μW m-2 sr-1 (10 Habing units). The 269 μm H2O line is observed toward the Galactic center in absorption.
Referência(s)