Age and metallicity gradients in the Galactic Bulge : A differential study using HST/WFPC2 observations

Feltzing, Sofia; Gilmore, Gerry (1999). Age and metallicity gradients in the Galactic Bulge : A differential study using HST/WFPC2 observations. Astrophysics and Space Science, 265, (1-4), 337 - 340
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Authors:
Feltzing, Sofia ; Gilmore, Gerry
Abstract:

We test for age and metallicity gradients in the Galactic Bulge between the two low extinction windows Baade's window (l = 1°.1 b = -4°.8) and Sagittarius-I (l = 1°.3 b = -2°.7). We derive a metallicity difference of ≤ 0.2 dex between BW and SGR-I window. This corresponds to a metallicity gradient of 1.3 dex kpc-1. This steep gradient is reconcilable with the existence of a short scale length inner component to the Bulge, most likely that prominent in the NIR, which perhaps forms a separate entity superimposed on the larger, optical Bulge. Through number counts in colour-magnitude diagram around the turnoff for several fields and clusters, extending over a range in galactic longitude we find no evidence for a significant young stellar population in the Galactic Bulge. Previous suggestions of the existence of a significant young stellar population have most likely incorrectly identified the foreground disk stars.

ISSN:
0004-640X
LUP-ID:
681d5c7b-bbdc-4183-83ea-32eb6bdb063e | Link: https://lup.lub.lu.se/record/681d5c7b-bbdc-4183-83ea-32eb6bdb063e | Statistics

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