PHANGS–JWST First Results: Destruction of the PAH Molecules in H ii Regions Probed by JWST and MUSE [PDF]
The Astrophysical Journal Letters, 2023 Polycyclic aromatic hydrocarbons (PAHs) play a critical role in the reprocessing of stellar radiation and balancing the heating and cooling processes in the interstellar medium but appear to be destroyed in H ii regions.
Oleg V. Egorov +32 more
doaj +2 more sources
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
openaire +8 more sources
New Infrared Sources Associated with H II Regions [PDF]
Symposium - International Astronomical Union, 1973 Photometry and mapping in the wavelength range 1.65–20 μ of the H II regions W3 and NGC 7538 have led to the discovery of a dozen new infrared emission sources. The sources have flux densities ranging up to 10–23 Wm–2 Hz–1 at 20 μ and diameters from < 3 to 40″.
C. G. Wynn-Williams +2 more
openaire +2 more sources
Metallicity Structure in the Milky Way Disk Revealed by Galactic H ii Regions [PDF]
Astrophysical Journal, 2019 The metallicity structure of the Milky Way disk stems from the chemodynamical evolutionary history of the Galaxy. We use the National Radio Astronomy Observatory Karl G.
T. Wenger +3 more
semanticscholar +3 more sources
Astronomy & Astrophysics, 2018 Aims. We aim to identify bipolar Galactic H II regions and to understand their parental cloud structures, morphologies, evolution, and impact on the formation of new generations of stars. Methods. We use the Spitzer-GLIMPSE, Spitzer-MIPSGAL, and Herschel-Hi-GAL surveys to identify bipolar H II regions and to examine their morphologies.
Samal, M. +5 more
openaire +3 more sources
Oxygen and helium abundances in Galactic H ii regions — II. Abundance gradients [PDF]
, 2000 L. Deharveng +3 more
semanticscholar +2 more sources
ATOMS: ALMA three-millimeter observations of massive star-forming regions – III. Catalogues of candidate hot molecular cores and hyper/ultra compact H ii regions [PDF]
Monthly notices of the Royal Astronomical Society, 2021 We have identified 453 compact dense cores in 3 mm continuum emission maps in the ALMA Three-millimetre Observations of Massive Star-forming regions survey, and compiled three catalogues of high-mass star-forming cores.
Hongli Liu +52 more
semanticscholar +1 more source
Studies of ultracompact H ii regions — II. High-resolution radio continuum and methanol maser survey [PDF]
, 1998 A. Walsh +3 more
semanticscholar +2 more sources
Ionization correction factors and dust depletion patterns in giant H ii regions [PDF]
, 2021 We provide new ionization correction factors (ICFs) for carbon, nitrogen, neon, sulfur, chlorine, and argon in giant H ii regions. The ICFs were computed using the most representative photoionization models from a large initial grid.
A. Amayo +2 more
semanticscholar +1 more source
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
doaj +1 more source