Academic Journal
TO APPEAR IN THE ASTROPHYSICAL JOURNAL LETTERS Preprint typeset using L ATEX style emulateapj v. 04/03/99 FAR-ULTRAVIOLET EMISSION FROM ELLIPTICAL GALAXIES AT z = 0.33 1
| العنوان: | TO APPEAR IN THE ASTROPHYSICAL JOURNAL LETTERS Preprint typeset using L ATEX style emulateapj v. 04/03/99 FAR-ULTRAVIOLET EMISSION FROM ELLIPTICAL GALAXIES AT z = 0.33 1 |
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| المؤلفون: | Thomas M. Brown, Henry C. Ferguson, Charles W. Bowers, Randy A. Kimble, R. Michael Rich |
| المساهمون: | The Pennsylvania State University CiteSeerX Archives |
| المصدر: | http://arxiv.org/pdf/astro-ph/0301364v1.pdf. |
| سنة النشر: | 2003 |
| المجموعة: | CiteSeerX |
| الوصف: | We present far-ultraviolet (far-UV) images of the rich galaxy cluster ZwCl1358.1+6245, taken with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope (HST). When combined with archival HST observations, our data provide a measurement of the UV-to-optical flux ratio in 8 early-type galaxies at z = 0.33. Because the UV flux originates in a population of evolved, hot, horizontal branch (HB) stars, this ratio is potentially one of the most sensitive tracers of age in old populations – it is expected to fade rapidly with lookback time. We find that the UV emission in these galaxies, at a lookback time of 3.9 Gyr, is significantly weaker than it is in the current epoch, yet similar to that in galaxies at a lookback time of 5.6 Gyr. Taken at face value, these measurements imply different formation epochs for the massive ellipticals in these clusters, but an alternative explanation is a “floor ” in the UV emission due to a dispersion in the parameters that govern HB morphology. |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.256.3255; http://arxiv.org/pdf/astro-ph/0301364v1.pdf |
| الاتاحة: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.256.3255 http://arxiv.org/pdf/astro-ph/0301364v1.pdf |
| Rights: | Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
| رقم الانضمام: | edsbas.752C586B |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |