An accurate determination of the slope of the UV continuum in z ~ 3 star-forming galaxies

4th Young Researcher Meeting, Trieste 2013

Pilo, Stefano^1

INAF, Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monteporzio (RM), Italy^1

关键词: Dust extinctions;    Galaxy evolution;    High redshift-galaxies;    Image simulations;    Measurements of;    Selection criteria;    Star formation rates;    Star forming galaxy;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/470/1/012010/pdf
DOI  :  10.1088/1742-6596/470/1/012010

来源: IOP

【 摘 要 】

Measuring dust extinction in high-redshift galaxies is fundamental to estimate the star formation rate density and constrain galaxy evolution models. I measure dust extinction in Lyman break galaxies at z ∼ 3 where a broad peak in the star formation rate density is thought to occur. On the basis of image simulations I perform a new method for accurate extraction of colours from images with different point spread functions. Taking advantage of a new colour selection criterion I select a sample of 225 LBGs at redshift ∼ 3.2. The UV slope of the sampled galaxies is determined by a linear fit of the observed magnitudes through a proper set of filters coherently with the original definition of the slope β. By performing measurements of β through IZY filters I find -1.79; moreover I find that the β value strongly depends on the set of filters I use for linear fitting. I find a good agreement comparing the three bands fit in our sample with CANDELS GOODS-South data set at the same redshift. UV slope value fits well in the trend for which dust extinction increase at decreasing redshift.