Results 21 to 30 of about 1,144,964 (311)
The Chocolate Chip Cookie Model: Dust-to-metal Ratio of H ii Regions
The Astrophysical Journal Letters, 2023 Using a sample of face-on star-forming galaxies selected from the Sloan Digital Sky Survey, we statistically derive the typical optical depth τ _cl of individual H ii regions based on the “Chocolate Chip Cookie” model of Lu et al. (2022).
Jiafeng Lu +3 more
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H II regions with He II emission [PDF]
Publications of the Astronomical Society of the Pacific, 1991 H II regions which exhibit surprisingly strong nebular He II λ4686 emission, with I(λ4686)/I (Hβ) as high as 0.3 in some cases. The He II emission in-these objects is associated with a rather diverse set of stars, with WO stars, very early WN stars, and luminous X-ray binaries involved, and in one case what appears to be a normal O-type star. Extension
Donald R. Garnett +3 more
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Diffuse continuum transfer in H���ii regions [PDF]
Monthly Notices of the Royal Astronomical Society, 2009 12 pages, 7 figures, to be published in ...
Williams, R. J. R., Henney, W. J.
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Stellar associations powering H II regions
Astronomy & AstrophysicsNewly formed stars profoundly affect their environment by depositing energy and momentum into the surrounding gas. However, only a fraction of the stellar feedback is retained in the cloud, and observational constraints are needed to improve our ...
Scheuermann Fabian +29 more
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The observational signature of the first H ii regions [PDF]
Monthly Notices of the Royal Astronomical Society, 2009 13 pages, 7 figures, published in ...
Greif, Thomas H. +3 more
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Massive Star Formation in the Ultraviolet Observed with the Hubble Space Telescope
Galaxies, 2020 Spectroscopic observations of a massive star formation in the ultraviolet and their interpretation are reviewed. After a brief historical retrospective, two well-studied resolved star clusters and the surrounding H II regions are introduced: NGC 2070 in ...
Claus Leitherer
doaj +1 more source
The Astrophysical JournalWe employ observations of the 205 μ m [N ii ] fine structure (FS) line and radio recombination line (RRL) emission to derive the electron density in 10 well-known H ii regions. The combination of these two spectral lines (the RRL–FS line method) provides
Paul. F. Goldsmith +4 more
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Pediatric Blood &Cancer, EarlyView.ABSTRACT Primary lung carcinomas and bronchial carcinoid tumors (BC) are very rare malignancies in childhood. While typical BC and mucoepidermoid carcinomas are mostly low‐grade, localized tumors with a more favorable prognosis than in adults, necessitating avoidance of overtreatment, adenocarcinomas of the lung are often diagnosed at advanced disease ...
Michael Abele +19 more
wiley +1 more source
New giant H II regions in the southern sky [PDF]
, 2005 We present results of a search for giant H II regions in southern galaxies. Using high-resolution spectra, obtained with the Magellan Inamori Kyocera Echelle (MIKE) at the Las Campanas Magellan II telescope, we were able to resolve the emission-line ...
Bosch, Guillermo Luis +5 more
core +1 more source
The Astrophysical Journal, 1968 H II regions expansion around O, B and A stars due to interstellar hydrogen ionization by stellar radiation ...
R. C. Newman, W. I. Axford
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