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The FU Orionis binary system RNO 1B/1C

McMuldroch, Stuart and Blake, Geoffrey A. and Sargent, Anneila I. (1995) The FU Orionis binary system RNO 1B/1C. Astronomical Journal, 110 (1). pp. 354-365. ISSN 0004-6256.

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Observations of CS (7→6) emission reveal a ≥3M_⊙ core, 1.8×10^4 AU in size, surrounding the FU Orionis binary system RNO 1B/1C. Fractional chemical abundances, calculated from LVG and LTE codes, are mostly similar to those in the cold core TMC 1. However, values for Si0/H_2 and CH_(3)0H/H_2 are enhanced, possibly by sputtering reactions or grain-grain collisions in tile outflow associated with the young stars. Aperture syntllesis maps of tile 2.6 and 3.1 mm continuum emission at ~5" and ~9" resolution, respectively, reveal that RNO 1C is surrounded by a flattened, dusty envelope, ~5000 AU in size, with mass ≥1.1 M_⊙. High spatial resolution (~3") interferometer observations of CS (2→1) emission may trace the dense walls of ail outflow cavity comprised of two concentric arcs with dynamical ages of 4×10^3 and 1×10^4 yr. The velocity structure of lower density gas imaged in the CO (1→0) transition is consistent with the arcs being formed by two energetic FU Orionis outbursts. Each event may have imparted more than 4 M_⊙km s^(-1) to the outflow, implying outburst mass loss rates of ~10^(-4) M_⊙ yr^(-1). It appears that RNO 1C is probably the driving source for the outflow and tllat, while pre-main sequence stars are in tile FU Orionis stage, outbursts may dominate both outflow morphology and energetics.

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URLURL TypeDescription
Blake, Geoffrey A.0000-0003-0787-1610
Sargent, Anneila I.0000-0002-4633-5098
Additional Information:© 1995 American Astronomical Society. Received 1994 June 8; revised 1994 September 19. We are indebted to the staff of the Owens Valley millimeter-wave array and the Caltech Submillimeter Observatory for their unfailing support and extend special thanks to Taco for his assistance with the CSO mapping software. We are extremely grateful to Ewine van Dishoeck and Todd Groesbeck for providing use of their LVG and LTE codes. We extend our thanks to the referee for many helpful suggestions. Astronomy with the Owens Valley Array is funded by NSF Grant AST 93-14079 and the CSO by NSF Grant AST 93-13929. S.M. is supported by NASA Grants NAGW-2297 and NAGW-3140, part of the Origins of Solar Systems Research Program.
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NSFAST 93-14079
NSFAST 93-13929
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Deposited On:13 Sep 2012 18:41
Last Modified:03 Oct 2019 04:15

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