Observations of absorption by water vapor toward Sagittarius B2
Journal or Book Title
We have observed the 110-101 pure rotational transitions of both H216O and H218O toward Sagittarius B2 using the Submillimeter Wave Astronomy Satellite. The spectra thereby obtained show a complex pattern of absorption and—in the case of H216O—emission, with numerous features covering a wide range of LSR velocities (-130 to 130 km s-1) and representing absorption both in gas associated with Sgr B2 as well as by several components of foreground gas along the line of sight. The ortho-water abundance derived for the absorbing foreground gas is ~6 × 10-7 relative to H2.
Neufeld, DA; Ashby, MLN; Bergin, EA; Chin, G; Erickson, NR; Goldsmith, PF; Harwit, M; Howe, JE; Kleiner, SC; Koch, DG; Patten, BM; Plume, R; Schieder, R; Snell, Ronald L.; Stauffer, JR; Tolls, V; Wang, Z; Winnewisser, G; Zhang, YF; and Melnick, GJ, "Observations of absorption by water vapor toward Sagittarius B2" (2000). ASTROPHYSICAL JOURNAL. 635.