A dataset provided by the European Space Agency

Name PROP_190
Title H II REGIONS ASSOCIATED WITH YOUNG GALACTIC CLUSTERS: COMPARISON OF STELLAR AND NEBULAR CHEMICAL COMPOSITIONS.
URL

http://nida.esac.esa.int/nida-sl-tap/data?RETRIEVAL_TYPE=OBSERVATION&PRODUCT_LEVEL=ALL&obsno=838016010
DOI https://doi.org/10.5270/esa-zm3eqey
Author DUFTON, PHILIP L
Description from model atmosphere analyses of the spectra of b-type stars in young clusters, we have found zero galactic abundance gradients for the solar neighbourhood (i.e. within 3 kpc of the sun). at larger galactocentic distances, we find considerable abundance variations over relatively small distance scales (i.e. ~1 kpc). these results are significantly different from those deduced from h ii region observations. however our discussion of these discrepancies has been compromised by the lack of data for both the b-type stars and their associated h ii regions. we therefore plan to observe with iso the h ii regions directly associated with early-type stars that we have previously analysed viz. s 208, s 212 and s 285 for a spring and the first two only for an autumn launch. the iso observations will be supplemented with our existing optical data for the h ii regions plus new observations, which will be obtained using time recently awarded to us on the 4.2 m william herschel telescope. the nebular abundances will be compared with the b-type stellar values, which will allow us to investigate if the discrepancies discussed above are due to: (a) errors in (probably) the h ii region analyses, (b) variations in their dust content, and/or (c) the stellar observations identifying abundance variations on a small spatial scale beyond those seen in the h ii region results. as h ii regions are used extensively to map abundances in external galaxies, it is important that these discrepancies are understood.
Instrument LWS01 , SWS02
Temporal Coverage 1998-03-02T21:09:56Z/1998-03-02T22:23:24Z
Version 1.0
Mission Description The Infrared Space Observatory (ISO) was the worlds first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
Creator Contact https://support.cosmos.esa.int/iso/
Date Published 1999-03-24T00:00:00Z
Last Update 2026-03-02
Keywords Infrared Space Observatory data, ESA ISO mission dataset, ISO infrared observations, mid-infrared astronomy data, far-infrared spectroscopy dataset, ISOCAM imaging data, ISOPHOT photometry data, SWS short wavelength spectrometer data, LWS long wavelength spectrometer data, infrared spectral line observations, infrared imaging survey data, dust emission infrared observations, star formation infrared dataset, interstellar medium spectroscopy data, polycyclic aromatic hydrocarbons PAH features data, active galactic nuclei infrared observations, circumstellar envelope infrared data, planetary nebula infrared spectroscopy, extragalactic infrared survey data, calibrated ISO data products, FITS files infrared astronomy, spectral energy distribution infrared data, continuum photometry dataset, infrared spectral cubes, flux-calibrated infrared maps, ESA ISO Data Archive, legacy infrared space mission dataset
Publisher And Registrant European Space Agency
Credit Guidelines European Space Agency, DUFTON et al., 1999, 'H II REGIONS ASSOCIATED WITH YOUNG GALACTIC CLUSTERS: COMPARISON OF STELLAR AND NEBULAR CHEMICAL COMPOSITIONS.', 1.0, European Space Agency, https://doi.org/10.5270/esa-zm3eqey