The Outflow and Accretion of Stellar Objects

A significant aspect of newly formed stars

Also known as stellar objects, is the ejection of materials. While matter is still accreting onto the identified protostar, mass is still lost vigorously through a wind in a bipolar manner which occurs perpendicularly to the rotation axis as well as the disk system (Morabito and Meyer 5). This perpendicular movement is influenced by two key mechanisms, X-wind model and disk wind, both relying on the magnetic fields to move the ionized gas outward while removing angular momentum from the disk. In the case of X-wind, coronial winds from the accretion disk and the central star combine to create a magnetized wind which is launched from some stellar radii. On the other hand, the disk wind mechanism which is launched from the disk surface may also push the materials in a perpendicular direction from as less as 1 AU to farthest as 100 AU (Kerr, Johnston, Hobbs, and Shannon 12). The materials can easily be launched outwardly due to the centrifugal support, and since X-wind derives from radii which are within the gravitational potential well of the star, this wind participates more in pushing the materials out of the star.

The protostellar jets and their role

Are observed to move in high velocity throughout the star-formation process since they regulate the activities by enabling matter to flow to the star center while also removing the angular momentum of the materials from the disk (Koupelis 382). Thus, the jets ensure they create a balance between outflow and accretion activities within the star objects; this scenario is supported by the fact that the outflow rates are about 0.01 to 0.1 times higher than the accretion rates (Salmeron and Ireland 1924). In the case that the velocity of the jet reduces, a balance in the outflow of materials between the disk and the star is interfered with, therefore, causing the star to disappear.

References

Kerr, Matthew, et al. “Limits on planet formation around young pulsars and implications for supernova fallback disks.” The Astrophysical Journal Letters 809.1 (2015): L11.

Koupelis, Theo. In Quest of the Universe. Sudbury, Mass: Jones and Bartlett Publishers, 2011. Print.

Morabito, Linda A., and David Meyer. ”Jets and Accretion Disks in Astrophysics-A Brief Review.” arXiv preprint arXiv:1211.0701 (2012).

Salmeron, Raquel, and Trevor Ireland. ”The role of protostellar jets in star formation and the evolution of the early solar system: Astrophysical and meteoritical perspectives.” Meteoritics & Planetary Science 47.12 (2012): 1922-1940.