A dataset provided by the European Space Agency

Name IRREGAL
Title EFFECTS OF METALLICITY ON STAR FORMING CLOUDS IN IRREGULAR GALAXIES
URL

http://nida.esac.esa.int/nida-sl-tap/data?RETRIEVAL_TYPE=OBSERVATION&PRODUCT_LEVEL=ALL&obsno=343009230
DOI https://doi.org/10.5270/esa-9rro5gv
Author MADDEN, SUZANNE C.
Description despite the fact that low metallicity dwarf irregular galaxies often have a paucity of observable co, they exhibit star formation activity that can be as high as that found in starburst galaxies. our recent kuiper airborne observatory (kao) observations, show that the 158 micron cii line is bright and extended in dwarf galaxies. the cii line intensities for the metal poor galaxies that we have detected with the kao are 1x10^4 to 6x10^4 times the co(1-0) line intensity. this effect is due to the decreased metallicity and dust content which results in reduced co cores surrounded by larger photodissociation regions. these observations suggest that the co(1-0) line may not be a good tracer of molecular gas in these galaxies since h2 may exhist in the cii zone. the kao is only able to detect a very limited number of dwarf galaxies due to its relatively poor sensitivity. thus, very few metal-poor low luminosity dwarf galaxies have been observed. we propose to extend our kao sample to lower luminosity irregular galaxies of varying metallicities with iso observations of cii, oi and nii. combined with co, fir continuum and 21 cm hi measurements, these observations will allow us to determine the physical conditions of the photodissociated gas in these galaxies. for the first time, we will be able to make a complete inventory of the gas reservoir in dwarf irregular galaxies where use of co alone to infer h2 may significantly underestimate the molecular mass. the results of this study will help to address unresolved questions about the physical properties of clouds and star formation processes in irregular galaxies.
Instrument LWS02
Temporal Coverage 1996-10-24T22:17:38Z/1998-02-04T18:14:09Z
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 1999-04-16T00:00:00Z
Last Update 2026-07-09
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, MADDEN et al., 1999, 'EFFECTS OF METALLICITY ON STAR FORMING CLOUDS IN IRREGULAR GALAXIES', 1.0, European Space Agency, https://doi.org/10.5270/esa-9rro5gv
Rights Data hosted in the ESA Space Science Archives are distributed under the CC BY-NC 3.0 IGO license.