Massive Stars and the Energy Balance of the Interstellar Medium. II. The 35<i>M</i><sub>⊙</sub>Star and a Solution to the “Missing Wind Problem”

Freyer, Tim; Hensler, G.; Yorke, H. W.

doi:10.1086/498734

Cited by 133 publications

(173 citation statements)

References 29 publications

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“…They agree with predictions from recent numerical simulations from Freyer et al (2003) and (Freyer et al 2006). The analysis by Freyer et al takes into account the action of the stellar wind and the ionizing flux from stars of 35 and 60 M and find that E kin E w is in the range 0.10−0.04.…”

Section: Scenariosupporting

confidence: 84%

Molecular gas toward G18.8+1.8

Vasquez

Rubio

Cappa

et al. 2012

A&A

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Aims. This work aims at investigating the characteristics of the molecular gas associated with the nebula G18.8+1.8, which is linked to the Wolf-Rayet star HD 168206 (WR 113), and its relation to other components of its local interstellar medium. Methods. We carried out molecular observations of the 12 CO(J = 1−0) and (J = 2−1) lines with an angular resolution of 44 and 22 using the SEST telescope. Complementary NANTEN data of the 12 CO(1−0) line were also used. The dust emission was analyzed using Spitzer-IRAC images at 8.0 μm, and WISE data at 3.4 μm, 4.6 μm, and 12.0 μm. Results. The SEST data allowed us to identify a molecular component (Cloud 3) that has velocities in the interval from ∼+30 to +36 km s −1 and is most probably linked to the nebula. Morphological and kinematical properties suggest that Cloud 3 consists of a wind-blown molecular half-shell, which expands around WR 113. The ratio R 2−1/1−0 and excitation temperatures indicate that the molecular gas is being irradiated by strong UV radiation. The location of the inner optical ring in the outer edge of Cloud 3 suggests that the stars SerOB2-1, -2, -3, -63, and -64 are responsables for the ionization of Cloud 3 and the inner ring nebula. A comparison between the spatial distribution of the molecular gas and the PAH emission at 8 μm indicates the existence of a photodissociation region between the ionized and the molecular gas. A search for candidate young stellar objects (YSOs) in the region around G18.8+1.8 based on available 2MASS, MSX, IRAS, and Spitzer-IRAC catalogs resulted in the detection of about sixty sources, some of them projected onto Cloud 3. Two small spots of clustered candidate YSOs are projected near the outer border of Cloud 3, although a triggered stellar formation scenario is doubtful.

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Section: Scenariosupporting

confidence: 84%

Molecular gas toward G18.8+1.8

Vasquez

Rubio

Cappa

et al. 2012

A&A

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“…Capriotti & Kozminski (2001) and Freyer et al (2003Freyer et al ( , 2006 developed analytical models and hydrodynamical simulations of H ii regions, including stellar winds. At the beginning of its evolution, the young H ii region should not be significantly affected by the wind of its exciting star(s).…”

Section: Morphology and Evolution Of An H II Regionmentioning

confidence: 99%

A gallery of bubbles

Deharveng

Schüller

Anderson

et al. 2010

A&A

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584

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Context. This study deals with infrared bubbles, the H ii regions they enclose, and triggered massive-star formation on their borders.Aims. We attempt to determine the nature of the bubbles observed by Spitzer in the Galactic plane, mainly to establish if possible their association with massive stars. We take advantage of the very simple morphology of these objects to search for star formation triggered by H ii regions, and to estimate the importance of this mode of star formation.Methods. We consider a sample of 102 bubbles detected by Spitzer-GLIMPSE, and catalogued by Churchwell et al. (2006; hereafter CH06). We use mid-infrared and radio-continuum public data (respectively the Spitzer-GLIMPSE and -MIPSGAL surveys and the MAGPIS and VGPS surveys) to discuss their nature. We use the ATLASGAL survey at 870 μm to search for dense neutral material collected on their borders. The 870 μm data traces the distribution of cold dust, thus of the dense neutral material where stars may form. Results. We find that 86% of the bubbles contain ionized gas detected by means of its radio-continuum emission at 20-cm. Thus, most of the bubbles observed at 8.0 μm enclose H ii regions ionized by O-B2 stars. This finding differs from the earlier CH06 results (∼25% of the bubbles enclosing H ii regions). Ninety-eight percent of the bubbles exhibit 24 μm emission in their central regions. The ionized regions at the center of the 8.0 μm bubbles seem to be devoid of PAHs but contain hot dust. PAH emission at 8.0 μm is observed in the direction of the photodissociation regions surrounding the ionized gas. Among the 65 regions for which the angular resolution of the observations is high enough to resolve the spatial distribution of cold dust at 870 μm, we find that 40% are surrounded by cold dust, and that another 28% contain interacting condensations. The former are good candidates for the collect and collapse process, as they display an accumulation of dense material at their borders. The latter are good candidates for the compression of pre-existing condensations by the ionized gas. Thirteen bubbles exhibit associated ultracompact H ii regions in the direction of dust condensations adjacent to their ionization fronts. Another five show methanol masers in similar condensations. Conclusions. Our results suggest that more than a quarter of the bubbles may have triggered the formation of massive objects.Therefore, star formation triggered by H ii regions may be an important process, especially for massive-star formation.

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“…The sum in the above equation includes mass loss via different types of winds ejected by the star at different stages of stellar evolution: the main sequence stage ( Eldridge (2009). This includes the mass-loss rate from the slow red supergiant stage wind ΔM RSGS 19 M (Freyer et al 2006). Therefore, the remaining 10M of the hot intercloud gas in the γ 2 Velorum SWB correspond to fast MSS and WR winds.…”

Section: Implications For the Models Of The Wolf-rayet Starmentioning

confidence: 99%

“…We can compare these estimates with the results of numerical simulations of stellar wind bubbles around WR stars. Numerical simulations of the evolution of a star with an initial mass M ini = 35 M , as proposed by Eldridge (2009) for WR11, were made by Freyer et al (2006) for an environment with a density of n 0 = 20 cm −3 and a temperature of T 0 = 200 K. They show that at the end of the calculations (before the SN explosion) the hot gas bubble has a mean radius of 34 pc and shell-like HII and HI regions of the swept up ambient gas extend out to a distance of 43−44 pc, the total mass is 1.5 × 10 5 M , the kinetic energy is 4.9 × 10 49 erg, the thermal energy of the hot gas is 1.1 × 10 50 erg, of the warm gas 4.3 × 10 49 erg, i.e., the radius, total mass and total energy (kinetic and thermal, 2×10 50 erg) are surprisingly close to our estimate for γ 2 Velorum. Nevertheless, two important differences should be clarified for γ 2 Velorum namely, the kinetic energy dominance and the low density of the ISM.…”

Section: Ivsmentioning

confidence: 99%

Modeling of the Vela complex including the Vela supernova remnant, the binary systemγ² Velorum, and the Gum nebula

Sushch

Hnatyk

Neronov

2010

A&A

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We study the geometry and dynamics of the Vela complex including the Vela supernova remnant (SNR), the binary system γ 2 Velorum and the Gum nebula. We show that the Vela SNR belongs to a subclass of non-Sedov adiabatic remnants in a cloudy interstellar medium (ISM), the dynamics of which is determined by the heating and evaporation of ISM clouds. We explain observable characteristics of the Vela SNR with a SN explosion with energy 1.4 × 10 50 erg near the step-like boundary of the ISM with low intercloud densities (∼10 −3 cm −3 ) and with a volume-averaged density of clouds evaporated by shock in the north-east (NE) part about four times higher than the one in the south-west (SW) part. The observed asymmetry between the NE and SW parts of the Vela SNR could be explained by the presence of a stellar wind bubble (SWB) blown by the nearest-to-the Earth Wolf-Rayet (WR) star in the γ 2 Velorum system. We show that the size and kinematics of γ 2 Velorum SWB agree with predictions of numerical calculations for the evolution of the SWB of M ini = 35 M star. The low initial mass of the WR star in γ 2 Velorum implies that the luminosity of the nuclear line of 26 Al, produced by γ 2 Velorum, is below the sensitivity of existing gamma-ray telescopes.

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Massive Stars and the Energy Balance of the Interstellar Medium. II. The 35M_⊙Star and a Solution to the “Missing Wind Problem”

Cited by 133 publications

References 29 publications

Molecular gas toward G18.8+1.8

Molecular gas toward G18.8+1.8

A gallery of bubbles

Modeling of the Vela complex including the Vela supernova remnant, the binary systemγ² Velorum, and the Gum nebula

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Massive Stars and the Energy Balance of the Interstellar Medium. II. The 35M⊙Star and a Solution to the “Missing Wind Problem”

Cited by 133 publications

References 29 publications

Molecular gas toward G18.8+1.8

Molecular gas toward G18.8+1.8

A gallery of bubbles

Modeling of the Vela complex including the Vela supernova remnant, the binary systemγ2 Velorum, and the Gum nebula

Contact Info

Product

Resources

About

Massive Stars and the Energy Balance of the Interstellar Medium. II. The 35M_⊙Star and a Solution to the “Missing Wind Problem”

Modeling of the Vela complex including the Vela supernova remnant, the binary systemγ² Velorum, and the Gum nebula