Skip to main content Accessibility help
×
Home
Hostname: page-component-846f6c7c4f-rmx46 Total loading time: 0.464 Render date: 2022-07-06T20:39:11.131Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true } hasContentIssue true

Book contents

UV Spectroscopy of Giant Extragalactic HII Regions: the Case of NGC 604

Published online by Cambridge University Press:  10 November 2010

G. Tenorio-Tagle
Affiliation:
Instituto de Astrofísica de Canarias, Tenerife
Lourdes Sanz Fernández de Cordoba
Affiliation:
Lab. Astrofísica Espacial y Física Fundamental, Instituto Nacional de Técnica Aeroespacial, Apartado 50727, 28080–Madrid, Spain
Get access

Summary

The UV spectrum of a giant extragalactic HII region is compared here with the synthetic spectrum generated by a fitting procedure which uses a combination of stellar spectra to match the observed spectrum.

Observations

The ultraviolet observations of giant extragalactic HII regions provide very valuable information on the stellar population embedded in these complexes.

The UV spectra of HII regions in the IUE short-wavelength range, SWP (1152–1950Å), show a stellar continuum which rises steeply towards the shorter wavelengths. Superposed over this continuum, emission lines and P-Cygni profiles are often observed, as an indication of the presence of hot luminous early-type stars with mass loss.

NGC 604, the brightest HII complex in the nearby galaxy M33, is, because of its size and distance, a good candidate for a detailed study of a giant extragalactic HII region in the UV based on IUE data.

NGC 604 has been observed with IUE on different occasions in low resolution (6 Å mm−1) with the large aperture slit (10 × 20 arcsec). A total of 16 SWP and 8 LWR, or LWP (1950–3200 Å), has been obtained. The spectra correspond to observations of different zones within the region.

The general characteristics of the IUE spectra of NGC 604 in the short wavelength range are similar to the ones mentioned above. In the near UV, the observed continuum is practically constant, no emission lines are detected, there is no 2200-Å absorption feature, and only interstellar absorption lines are present.

Type
Chapter
Information
Violent Star Formation
From 30 Doradus to QSOs
, pp. 41 - 42
Publisher: Cambridge University Press
Print publication year: 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Save book to Kindle

To save this book to your Kindle, first ensure coreplatform@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×