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Measuring Metallicities with HST/WFC3 photometry
dc.contributor.author | Ross, Teresa L. | |
dc.contributor.author | Holtzman, Jon | |
dc.contributor.author | Anthony-Twarog, Barbara | |
dc.contributor.author | Bond, Howard | |
dc.contributor.author | Twarog, Bruce A. | |
dc.contributor.author | Saha, Abhijit | |
dc.contributor.author | Walker, Alistair | |
dc.date.accessioned | 2015-12-21T19:37:36Z | |
dc.date.available | 2015-12-21T19:37:36Z | |
dc.date.issued | 2013-10-17 | |
dc.identifier.citation | Ross, Teresa L., Jon A. Holtzman, Barbara J. Anthony-Twarog, Howard E. Bond, Bruce Twarog, Abhijit Saha, and Alistair Walker. "Measuring Metallicities With Hubble Space Telescope /wide-Field Camera 3 Photometry." The Astronomical Journal 147.1 (2013): 4. http://arxiv.org/abs/1310.4553 | en_US |
dc.identifier.uri | http://hdl.handle.net/1808/19318 | |
dc.description | This is the published version. Copyright 2013 American Astronomical Society | en_US |
dc.description.abstract | We quantified and calibrated the metallicity and temperature sensitivities of colors derived from nine Wide Field Camera 3 (WFC3) filters aboard the Hubble Space Telescope using Dartmouth isochrones and Kurucz atmospheres models. The theoretical isochrone colors were tested and calibrated against observations of five well studied galactic clusters: M92, NGC 6752, NGC 104, NGC 5927, and NGC 6791, all of which have spectroscopically determined metallicities spanning -2.30 < [Fe/H] < +0.4. We found empirical corrections to the Dartmouth isochrone grid for each of the following color magnitude diagrams (CMD) (F555W--F814W, F814W), (F336W-F555W, F814W), (F390M-F555W, F814W) and (F390W-F555W, F814W). Using the empirical corrections we tested the accuracy and spread of the photometric metallicities assigned from CMDs and color-color diagrams (which are necessary to break the age-metallicity degeneracy). Testing three color-color diagrams [(F336W-F555W),(F390M-F555W),(F390W-F555W), vs (F555W-F814W)], we found the colors (F390M-F555W) and (F390W-F555W), to be the best suited to measure photometric metallicities. The color (F390W-F555W) requires much less integration time, but generally produces wider metallicity distributions, and, at very-low metallicity, the MDF from (F390W-F555W) is ~60% wider than that from (F390M-F555W). Using the calibrated isochrones we recovered the overall cluster metallicity to within ~0.1 dex in [Fe/H] when using CMDs (i.e. when the distance, reddening and ages are approximately known). The measured metallicity distribution function (MDF) from color-color diagrams show this method measures metallicities of stellar clusters of unknown age and metallicity with an accuracy of ~0.2 - 0.5 dex using F336W--F555W, ~0.15 - 0.25 dex using F390M-F555W, and ~0.2 - 0.4 dex with F390W-F555W, with the larger uncertainty pertaining to the lowest metallicity range. | en_US |
dc.publisher | American Astronomical Society | en_US |
dc.relation.isversionof | http://arxiv.org/abs/1310.4553 | en_US |
dc.title | Measuring Metallicities with HST/WFC3 photometry | en_US |
dc.type | Article | |
kusw.kuauthor | Anthony-Twarog, Barbara | |
kusw.kudepartment | Physics and Astronomy | en_US |
kusw.oaversion | Scholarly/refereed, publisher version | |
kusw.oapolicy | This item meets KU Open Access policy criteria. | |
dc.rights.accessrights | openAccess |