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University of Massachusetts Amherst

2000

ISM: abundances

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Submillimeter Wave Astronomy Satellite Observations Of Extended Water Emission In Orion, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick Oct 2000

Submillimeter Wave Astronomy Satellite Observations Of Extended Water Emission In Orion, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick

Neal Erickson

We have used the Submillimeter Wave Astronomy Satellite to map the ground-state 1_{10}-1_{01} transition of ortho-water at 557 GHz in the Orion molecular cloud. Water emission was detected in Orion over an angular extent of about 20 arcmin, or nearly 3 pc. The water emission is relatively weak, with line widths (3-6 km s^{-1}) and V_{LSR} velocities (9-11 km s^{-1}) consistent with an origin in the cold gas of the molecular ridge. We find that the ortho-water abundance relative to H_2 in the extended gas in Orion varies between 1 and 8x10^{-8}, with an average of 3x10^{-8}. The absence of …


The Distribution Of Water Emission In M17sw, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick Aug 2000

The Distribution Of Water Emission In M17sw, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick

Neal Erickson

We present a 17-point map of the M17SW cloud core in the 1_{10}-1_{01} transition of ortho-water at 557 GHz obtained with the Submillimeter Wave Astronomy Satellite. Water emission was detected in 11 of the 17 observed positions. The line widths of the water emission vary between 4 and 9 km s^{-1}, and are similar to other emission lines that arise in the M17SW core. A direct comparison is made between the spatial extent of the water emission and the ^{13}CO J = 5\to4 emission; the good agreement suggests that the water emission arises in the same warm, dense gas as …


Water Abundance In Molecular Cloud Cores, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick Aug 2000

Water Abundance In Molecular Cloud Cores, R. L. Snell, J. E. Howe, M. L. N. Ashby, E. A. Bergin, G. Chin, Neal A. Erickson, P. F. Goldsmith, M. Harwit, S. C. Kleiner, D. G. Koch, D. A. Neufeld, B. M. Patten, R. Plume, R. Schieder, J. R. Stauffer, V. Tolls, Z. Wang, G. Winnewisser, Y. F. Zhang, G. J. Melnick

Neal Erickson

We present Submillimeter Wave Astronomy Satellite (SWAS) observations of the 1_{10}-1_{01} transition of ortho-water at 557 GHz toward 12 molecular cloud cores. The water emission was detected in NGC 7538, Rho Oph A, NGC 2024, CRL 2591, W3, W3(OH), Mon R2, and W33, and was not detected in TMC-1, L134N, and B335. We also present a small map of the water emission in S140. Observations of the H_2^{18}O line were obtained toward S140 and NGC 7538, but no emission was detected. The abundance of ortho-water relative to H_2 in the giant molecular cloud cores was found to vary between 6x10^{-10} …