Results 11 to 20 of about 1,094,944 (319)
Spatially Resolved Temperature and Density Structures of Nearby H ii Regions
The Astrophysical Journal, 2023 Photoionization models frequently assume constant temperature or density within H ii regions. We investigate this assumption by measuring the detailed temperature and density structures of four H ii regions in the Large Magellanic Cloud and the Small ...
Yifei Jin +3 more
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Clustered Formation of Massive Stars within an Ionized Rotating Disk
The Astrophysical Journal Letters, 2022 We present Atacama Large Millimeter/submillimeter Array observations with a 800 au resolution and radiative-transfer modeling of the inner part ( r ≈ 6000 au) of the ionized accretion flow around a compact star cluster in formation at the center of the ...
Roberto Galván-Madrid +9 more
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Excited Hydroxyl Outflow in the High-mass Star-forming Region G34.26 + 0.15
The Astrophysical Journal, 2023 G34.26 + 0.15 is a region of high-mass star formation that contains a broad range of young stellar objects in different stages of evolution, including a hot molecular core, hypercompact H ii regions, and a prototypical cometary ultracompact H ii region ...
Wei Siang Tan +6 more
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Backscattering and Line Broadening in Orion
The Astronomical Journal, 2022 Examination of emission lines in high-velocity-resolution optical spectra of the Orion Nebula confirms that the velocity component on the red wing of the main ionization front emission line is due to backscattering in the Photon Dominated Region.
C. R. O’Dell +2 more
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Comparing Complex Chemistry in Neighboring Hot Cores: NOEMA Studies of W3(H2O) and W3(OH)
The Astrophysical Journal, 2023 Presented here are NOEMA interferometric observations of the neighboring hot cores W3(H _2 O) and W3(OH). The presence of two star-forming cores at different evolutionary stages within the same parent cloud presents a unique opportunity to study how the ...
Will E. Thompson +3 more
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Mapping Physical Conditions in Neighboring Hot Cores: NOEMA Studies of W3(H2O) and W3(OH)
The Astrophysical Journal, 2023 The complex chemistry that occurs in star-forming regions can provide insight into the formation of prebiotic molecules at various evolutionary stages of star formation.
Morgan M. Giese +3 more
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Expansive components in H II regions [PDF]
Astronomy & Astrophysics, 2005 16 pages, 9 figures, accepted for publication in A& ...
Relano, M., Beckman, J. E.
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Surveying the Giant H ii Regions of the Milky Way with SOFIA: V. DR7 and K3-50
The Astrophysical Journal, 2023 We present our fifth set of results from our mid-infrared imaging survey of Milky Way Giant H ii (GH ii ) regions with our detailed analysis of DR7 and K3-50.
James M. De Buizer +3 more
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A population of hypercompact H II regions identified from young H II regions [PDF]
Astronomy & Astrophysics, 2021 Context. The derived physical parameters for young H II regions are normally determined assuming the emission region to be optically thin. However, this assumption is unlikely to hold for young H II regions such as hyper-compact H II (HC H II) and ultra-compact H II (UC H II) regions and leads to underestimation of their properties.
Yang, AY +10 more
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Symposium - International Astronomical Union, 1973 The observed far infrared flux of H II regions is interpreted as evidence for the presence of internal dust absorbing a fraction of Lyman continuum photons. The effect of this dust on the required number of ionizing photons and on the helium to hydrogen line intensity ratios are discussed and analytic formulae describing these effects are presented for
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