The Formation of Massive Stars by Accretion through Trapped Hypercompact H II Regions

By E. Keto. 2003

167 citations recorded by the source corpus.

The formation of massive stars may take place at relatively low accretion rates over a long period of time if the accretion can continue past the onset of core hydrogen ignition. The accretion may continue despite the formation of an ionized H II region around the star if the H II region is small enough that the gravitational attraction of the star dominates the thermal pressure of the H II region. The accretion may continue despite radiation pressure acting against dust grains in the molecular gas if the momentum of the accretion flow is sufficient to push the dust grains through a narrow zone of high dust opacity at the ionization boundary and into the H II region where the dust is sublimated. This model of massive star formation by continuing accretion predicts a new class of gravitationally trapped, long-lived, hypercompact H II regions. The observational characteristics of the trapped hypercompact H II regions can be predicted for comparison with observations.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/4bea64cfb21f69e95435e0ca6f8dea3d94228d21

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Citations in the corpus

Theory of Star Formation (2007, background): “Keto (2002, 2003) has studied this model further, focusing on the associated H II regions.”
The 6-GHz multibeam maser survey-I. Techniques (2008, background): “…† Deceased 2006 November 1. rent star formation models encounter difficulties in creating stars much more massive than ∼8 M⊙ (e.g. Keto 2003; Yorke 2004) and observations of these events are hampered by the speed with which the process occurs, and hence the relative rarity…”
ATLASGAL — towards a complete sample of massive star forming clumps ⋆ (2014, background): “The association of these compact radio sources with methanol masers may indicate that accretion continues after the formation of the H II regions through ionized infall (Keto 2003, 2007) or through the partial shielding of the ionizing radiation by the accretion flow (Peters et al. 2010).”
Physical Processes in the Interstellar Medium (2014, background): “This means that accretion as well as ionizing and non-ionizing radiation needs to be considered in concert (Keto, 2002; Keto, 2003, 2007; Peters et al., 2010a; Peters et al., 2010b).”
LIMITING ACCRETION ONTO MASSIVE STARS BY FRAGMENTATION-INDUCED STARVATION (2010, background): “This means that accretion as well as ionizing and non-ionizing radiation needs to be considered in concert (Keto 2002, 2003, 2007; Peters et al. 2010a,b).”
A study of the Keplerian accretion disk and precessing outflow in the massive protostar IRAS 20126+4104 (2005, unknown): “As a matter of fact, the presence of infall in massive star forming regions has been observationally established (see e.g. Keto et al. 1988; Ho et al. 1996; Sollins et al. 2004) and theoretically predicted (Keto 2003) as a crucial phenomenon profoundly affecting the formation of early-type stars.”
CIRCUMVENTING THE RADIATION PRESSURE BARRIER IN THE FORMATION OF MASSIVE STARS VIA DISK ACCRETION (2010, background): “A formation of massive stars by breaking through the ionization boundary into regions of sublimated dust grains was studied for spherically symmetric accretion flows (Keto 2003) as well as for 2D effects in the socalled small radius limit (Jijina & Adams 1996).”
H II REGIONS: WITNESSES TO MASSIVE STAR FORMATION (2010, background): “The pressure of the 104 K ionized gas far exceeds that in the 102 K accreting molecular gas, producing feedback in the form of ionized outflows (Keto 2002, 2003, 2007).”
The Formation of Massive Stars: Accretion, Disks, and the Development of Hypercompact H II Regions (2006, methodology): “The hypothesis ofmassive star formation presented here, following Keto (2002b, 2003) suggests that both occur.”