An in-depth analysis of a prototypical giant H II region: NGC 604
Abstract
NGC 604 is, together with 30 Doradus, the extragalactic prototype giant H II region. Its stellar content and mass { 200 O+WR stars, 10**5 M_Sun}, age { 3.5 Myr}, proximity {840 kpc}, and low foreground extinction {E{B-V} <= 0.1} make it an ideal object to study the massive stellar population of a scaled OB association, its interaction with the surrounding medium, and the effects caused by the strong differential extinction. We propose new HST observations which, combined with existent ones, will provide the most thorough multi-wavelength study of NGC 604 from the FUV to the NIR. We will obtain spectral classifications for 200 stars, measure their spectral energy distributions from 1300 A to 2.2 microns, identify embedded very-young stellar populations hidden inside dust clouds, measure the extinction law and its possible variations as a function of environmental conditions, and analyze the relationship between the hot stars and the surrounding gas. The new data we are proposing is divided into three parts: {a} slitless objective-prism FUV spectroscopy using ACS/SBC, {b} multi-filter {6 broad-band and 2 narrow-band} NUV-optical imaging using ACS/HRC, and {c} HST/NICMOS broadband imaging. Our final goal is to analyze in detail a well-resolved giant H II region in order to understand the properties of similar but unresolved objects located at cosmological distances.
- Publication:
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HST Proposal
- Pub Date:
- July 2004
- Bibcode:
- 2004hst..prop10419B