Stellar haloes of disc galaxies at z ˜ 1

Trujillo, I.; Bakos, J.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society, Volume 431, Issue 2, p.1121-1135

Advertised on:
5
2013
Number of authors
2
IAC number of authors
2
Citations
32
Refereed citations
27
Description
Taking advantage of the ultradeep near-infrared imaging obtained with the Hubble Space Telescope on the Hubble Ultra Deep Field, we detect and explore for the first time the properties of the stellar haloes of two Milky Way-like galaxies at z ˜ 1. We find that the structural properties of those haloes (size and shape) are similar to the ones found in the local Universe. However, these high-z stellar haloes are approximately three magnitudes brighter and exhibit bluer colours ((g - r) ≲ 0.3 mag) than their local counterparts. The stellar populations of z ˜ 1 stellar haloes are compatible with having ages ≲1 Gyr. This implies that the stars in those haloes were formed basically at 1 < z < 2. This result matches very well the theoretical predictions that locate most of the formation of the stellar haloes at those early epochs. A pure passive evolutionary scenario, where the stellar populations of our high-z haloes simply fade to match the stellar halo properties found in the local universe, is consistent with our data.
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Traces of Galaxy Formation: Stellar populations, Dynamics and Morphology
We are a large, diverse, and very active research group aiming to provide a comprehensive picture for the formation of galaxies in the Universe. Rooted in detailed stellar population analysis, we are constantly exploring and developing new tools and ideas to understand how galaxies came to be what we now observe.
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