%0 Conference Paper %1 Shu1987 %A Shu, Frank H. %A Adams, Fred C. %B Circumstellar Matter %D 1987 %E Appenzeller, I. %E Jordan, C. %K 14MAST Astrophysics, Bipolar Circumstellar Clouds, Clouds:Star Collapse, Ejection, Emission Envelopes, Evolution, Formation, Formation:Bipolar Formation:Molecular Formation:T Gravitational Infrared Mass Matter Matter:Young Models, Molecular Outflows, Outflows:Star Protostars, Spectra, Star Stars, Stars:Circumstellar Stars:Star Stellar T Tauri Young astronomía %P 7 %T Star formation and the circumstellar matter of young stellar objects. %V 122 %X The authors propose that the formation of low mass stars in molecular clouds takes place in four stages. The first stage is the formation of slowly rotating cloud cores through the slow leakage of magnetic (and turbulent) support by ambipolar diffusion. The second phase begins when a condensing cloud core passes the brink of instability and collapses dynamically from ''inside-out'', building up a central protostar and nebular disk. The emergent spectral energy distributions of theoretical models in the infall stage are in close agreement with those of recently found infrared sources with steep spectra. As the rotating protostar gains mass, deuterium will eventually ignite in the central regions and drive the star nearly completely convective if its mass is less than about 2 M\_sun;. This initiates the next step of evolution - the bipolar outflow phase - in which a stellar wind pushes outward and breaks through the infalling envelope. The initial breakout is likely to occur along the rotational poles, leading to collimated jets and bipolar outflows. The intense stellar wind eventually widens to sweep out gas in nearly all 4\pi steradian, revealing the fourth stage - a T Tauri star with a surrounding remnant nebular disk. Radiation from a disk adds an infrared excess to the expected spectral energy distribution of the revealed source.

@inproceedings{Shu1987, __markedentry = {[oriol:6]}, abstract = {{The authors propose that the formation of low mass stars in molecular clouds takes place in four stages. The first stage is the formation of slowly rotating cloud cores through the slow leakage of magnetic (and turbulent) support by ambipolar diffusion. The second phase begins when a condensing cloud core passes the brink of instability and collapses dynamically from ''inside-out'', building up a central protostar and nebular disk. The emergent spectral energy distributions of theoretical models in the infall stage are in close agreement with those of recently found infrared sources with steep spectra. As the rotating protostar gains mass, deuterium will eventually ignite in the central regions and drive the star nearly completely convective if its mass is less than about 2 M\_sun;. This initiates the next step of evolution - the bipolar outflow phase - in which a stellar wind pushes outward and breaks through the infalling envelope. The initial breakout is likely to occur along the rotational poles, leading to collimated jets and bipolar outflows. The intense stellar wind eventually widens to sweep out gas in nearly all 4{\ensuremath{\pi}} steradian, revealing the fourth stage - a T Tauri star with a surrounding remnant nebular disk. Radiation from a disk adds an infrared excess to the expected spectral energy distribution of the revealed source.}}, added-at = {2019-11-04T18:50:55.000+0100}, adsnote = {Provided by the SAO/NASA Astrophysics Data System}, adsurl = {https://ui.adsabs.harvard.edu/\#abs/1987IAUS..122....7S}, author = {{Shu}, Frank H. and {Adams}, Fred C.}, biburl = {https://www.bibsonomy.org/bibtex/2cbde1d7a79b72b2204951b4575c94b8f/osso73}, booktitle = {Circumstellar Matter}, editor = {{Appenzeller}, I. and {Jordan}, C.}, interhash = {97f625007d403f2e766c9a75e3a9b07a}, intrahash = {cbde1d7a79b72b2204951b4575c94b8f}, keywords = {14MAST Astrophysics, Bipolar Circumstellar Clouds, Clouds:Star Collapse, Ejection, Emission Envelopes, Evolution, Formation, Formation:Bipolar Formation:Molecular Formation:T Gravitational Infrared Mass Matter Matter:Young Models, Molecular Outflows, Outflows:Star Protostars, Spectra, Star Stars, Stars:Circumstellar Stars:Star Stellar T Tauri Young astronomía}, month = Jan, pages = 7, series = {IAU Symposium}, timestamp = {2019-11-08T09:39:11.000+0100}, title = {{Star formation and the circumstellar matter of young stellar objects.}}, volume = 122, year = 1987 }