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Suzanne K. Ramsay, Watson P. Varricatt, Chris J. Davis et Stephen Todd
A near-infrared imaging survey of intermediate and high-mass young stellar object outflow candidatesAbstract
We present a new near-infrared imaging survey of 50 luminous young stellar outflow candidates. Using high spatial resolution observations in the v=1-0 S(1) line of H2 we detect the outflows with a high success rate: 76% of the objects exhibit H2 emission and 50% or more of the objects exhibit aligned H2 emission features suggesting collimated outflows. Many of these are new detections. The young stellar objects responsible for the outflows are positively identified in many of our images based on their locations with respect to the outflow lobes, 2MASS colours and association with MSX, IRAS, millimetre and radio sources. The main results of our survey are as follows. The observations suggest that disk accretion is probably the leading mechanism in the formation of stars, at least up to late O spectral types. The close association of molecular outflows detected in CO with the H2 emission features produced by shock excitation by jets from the young stellar objects suggests that the outflows from these objects are jet-driven. Towards strong radio emitting sources, H2 jets were either not detected or were weak when detected, implying that most of the accretion happens in the pre-UCHII phase; accretion and outflows are probably weak when the YSO has advanced to its UCHII stage. Documents annexes
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Pour citer cet article :
Suzanne K. Ramsay, Watson P. Varricatt, Chris J. Davis et Stephen Todd. «A near-infrared imaging survey of intermediate and high-mass young stellar object outflow candidates». Bulletin de la Société Royale des Sciences de Liège,
Volume 80 - Année 2011 : 235 - 240
http://popups.ulg.ac.be/SRSL/document.php?id=2710 Quelques mots à propos de : Suzanne K. RamsayEuropean Southern Observatory, Karl-Schwarschild-Strasse, 2, 85748 Garching, Germany, sramsay@eso.org Quelques mots à propos de : Watson P. VarricattJoint Astronomy Centre, 660, N.A’ohuku Place, Hilo, HI 96720, USA Quelques mots à propos de : Chris J. DavisJoint Astronomy Centre, 660, N.A’ohuku Place, Hilo, HI 96720, USA Quelques mots à propos de : Stephen ToddUK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ, UK.
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