* Astronomy

Blobrana · L

RE: Sharpless 2-106

Blobrana · L

Title: SOFIA observations of S106: Dynamics of the warm gas
Authors: Robert Simon, Nicola Schneider, Juergen Stutzki, Rolf Guesten, Urs Graf, Paul Hartogh, Xin Guan, Johannes Staguhn, Dominic Benford

Context. The HII region/PDR/molecular cloud complex S106 is excited by a single O-star. The full extent of the warm and dense gas close to the star has not been mapped in spectrally resolved high-J CO or [CII] lines, so the kinematics of the warm, partially ionised gas, are unknown. Whether the prominent dark lane bisecting the hourglass-shaped nebula is due solely to the shadow cast by a small disk around the exciting star or also to extinction in high column foreground gas was an open question until now.
Aims. To disentangle the morphology and kinematics of warm neutral and ionised gas close to the star, study their relation to the bulk of the molecular gas, and to investigate the nature of the dark lane.
Methods. We use the heterodyne receiver GREAT on board SOFIA to observe velocity resolved spectral lines of [C II] and CO 11-10 in comparison with so far unpublished submm continuum data at 350 micron (SHARC-II) and complementary molecular line data.
Results. The high angular and spectral resolution observations show a very complex morphology and kinematics of the inner S106 region, with many different components at different excitation conditions contributing to the observed emission. The [C II] lines are found to be bright and very broad, tracing high velocity gas close to the interface of molecular cloud and HII region. CO 11-10 emission is more confined, both spatially and in velocity, to the immediate surroundings of S106 IR showing the presence of warm, high density (clumpy) gas. Our high angular resolution submm continuum observations rule out the scenario where the dark lane separating the two lobes is due solely to the shadow cast by a small disk close to the star. The lane is clearly seen also as warm, high column density gas at the boundary of the molecular cloud and HII region.

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Blobrana · L

The bipolar star-forming region, called Sharpless 2-106, or S106 for short, looks like a soaring, celestial snow angel. The outstretched "wings" of the nebula record the contrasting imprint of heat and motion against the backdrop of a colder medium. Twin lobes of super-hot gas, glowing blue in this image, stretch outward from the central star. This hot gas creates the "wings" of our angel. A ring of dust and gas orbiting the star acts like a belt, cinching the expanding nebula into an "hourglass" shape.
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Blobrana · L

Sharpless 2-106 lies between Sadr and the Veil SNR in Cygnus. At first glance, it appears like a bipolar planetary nebula. However, it is not a PN. It is an emssion nebula. 600 pc distant and quite small at 0.5 pc long (~2000 and 1.6 light-years, respectively), and is ionised by an O8 star, S106IR.
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Position (J2000): R.A. 20 27 27.1 | Dec. +37° 22' 39''

Google earth file: Sh 2-106.kmz (2kb, kmz)

Blobrana · L

A dramatic new image from the Gemini North telescope illustrates the dynamic and sometimes violent process of star birth. It also demonstrates the capabilities of new filters available to researchers using the Gemini Multi-Object Spectrograph (GMOS).
Known as Sharpless 2-106 (Sh2-106), the hourglass-shaped (bipolar) nebula in the new Gemini image is a stellar nursery made up of glowing gas and light-scattering dust. The material shrouds a natal high-mass star thought to be mostly responsible for the hourglass shape of the nebula due to high-speed winds (more than 200 kilometres/second) which eject material from the forming star deep within (see the recent Gemini press release on the birth of a massive star which exhibits evidence of similar processes). Research also indicates that many sub-stellar objects are forming within the cloud and may someday result in a cluster of 50 to 150 stars in this region.

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