The physical nature of the 8 o'clock arc based on near-IR IFU spectroscopy with SINFONI
| Autor: | Shirazi, M., Vegetti, S., Nesvadba, N., Allam, S., Brinchmann, J., Tucker, D. |
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| Rok vydání: | 2013 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stu316 |
| Popis: | We present an analysis of near-infrared integral field unit spectroscopy of the 8 o'clock arc, a gravitationally lensed Lyman break galaxy, taken with SINFONI. We explore the shape of the spatially-resolved H\beta\ profile and demonstrate that we can decompose it into three components that partially overlap (spatially) but are distinguishable when we include dynamical information. We use existing B and H imaging from the Hubble Space Telescope to construct a rigorous lens model using a Bayesian grid based lens modelling technique. We apply this lens model to the SINFONI data cube to construct the de-lensed H\beta\ line-flux velocity and velocity dispersion maps of the galaxy. We find that the 8 o'clock arc has a complex velocity field that is not simply explained by a single rotating disk. The H\beta\ profile of the galaxy shows a blue-shifted wing suggesting gas outflows of ~ 200 km s^{-1}. We confirm that the 8 o'clock arc lies on the stellar mass--oxygen abundance--SFR plane found locally, but it has nevertheless significantly different gas surface density (a factor of 2--4 higher) and electron density in the ionized gas (five times higher) from those in similar nearby galaxies, possibly indicating a higher density interstellar medium for this galaxy. Comment: 23 pages, 25 figures |
| Databáze: | arXiv |
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