eCite Digital Repository

The ACS LCID Project. XI. On the early time resolution of SFHs of local group dwarf galaxies: comparing the effects of reionization in models with observations

Citation

Aparicio, A and Hidalgo, SL and Skillman, E and Cassisi, S and Mayer, L and Navarro, J and Cole, A and Gallart, C and Monelli, M and Weisz, D and Bernard, E and Dolphin, A and Stetson, P, The ACS LCID Project. XI. On the early time resolution of SFHs of local group dwarf galaxies: comparing the effects of reionization in models with observations, The Astrophysical Journal, 823, (1) Article 9. ISSN 0004-637X (2016) [Refereed Article]


Preview
PDF
468Kb
  

Copyright Statement

Copyright 2016 The American Astronomical Society

DOI: doi:10.3847/0004-637X/823/1/9

Abstract

The analysis of the early star formation history (SFH) of nearby galaxies, obtained from their resolved stellar populations, is relevant as a test for cosmological models. However, the early time resolution of observationally derived SFHs is limited by several factors. Thus, direct comparison of observationally derived SFHs with those derived from theoretical models of galaxy formation is potentially biased. Here we investigate and quantify this effect. For this purpose, we analyze the duration of the early star formation activity in a sample of four Local Group dwarf galaxies and test whether they are consistent with being true fossils of the pre-reionization era; i.e., if the quenching of their star formation occurred before cosmic reionization by UV photons was completed. Two classical dSph (Cetus and Tucana) and two dTrans (LGS-3 and Phoenix) isolated galaxies with total stellar masses between $1.3\times {10}^{6}$ and $7.2\times {10}^{6}$ ${M}_{\odot }$ have been studied. Accounting for time resolution effects, the SFHs peak as much as 1.25 Gyr earlier than the optimal solutions. Thus, this effect is important for a proper comparison of model and observed SFHs. It is also shown that none of the analyzed galaxies can be considered a true fossil of the pre-reionization era, although it is possible that the outer regions of Cetus and Tucana are consistent with quenching by reionization.

Item Details

Item Type:Refereed Article
Keywords:early universe, galaxies: dwarf, galaxies: evolution, galaxies: photometry, galaxies: stellar content, galaxies: structure
Research Division:Physical Sciences
Research Group:Astronomical and Space Sciences
Research Field:Cosmology and Extragalactic Astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Physical Sciences
Author:Cole, A (Dr Andrew Cole)
ID Code:112820
Year Published:2016
Web of Science® Times Cited:2
Deposited By:Mathematics and Physics
Deposited On:2016-11-30
Last Modified:2017-05-09
Downloads:3 View Download Statistics

Repository Staff Only: item control page