We study the properties of the circumgalactic medium (CGM) of high-$z$ galaxies in the metal enrichment simulations presented in Pallottini et al. 2014. At $z=4$, we find that the simulated CGM gas density profiles are self-similar, once scaled with the virial radius of the parent dark matter halo. We also find a simple analytical expression relating the neutral hydrogen equivalent width ($\rm EW_\rm HI$) of CGM absorbers as a function of the line of sight impact parameter ($b$). We test our predictions against mock spectra extracted from the simulations, and show that the model reproduces the $\rm EW_\rm HI(b)$ profile extracted from the synthetic spectra analysis. When compared with available data, our CGM model nicely predicts the observed $\rm EW_\rm HI(b)$ in $z\lesssim2$ galaxies, and supports the idea that the CGM profile does not evolve with redshift.
The circumgalactic medium of high-redshift galaxies
PALLOTTINI, ANDREA;GALLERANI, SIMONA;FERRARA, ANDREA
2014
Abstract
We study the properties of the circumgalactic medium (CGM) of high-$z$ galaxies in the metal enrichment simulations presented in Pallottini et al. 2014. At $z=4$, we find that the simulated CGM gas density profiles are self-similar, once scaled with the virial radius of the parent dark matter halo. We also find a simple analytical expression relating the neutral hydrogen equivalent width ($\rm EW_\rm HI$) of CGM absorbers as a function of the line of sight impact parameter ($b$). We test our predictions against mock spectra extracted from the simulations, and show that the model reproduces the $\rm EW_\rm HI(b)$ profile extracted from the synthetic spectra analysis. When compared with available data, our CGM model nicely predicts the observed $\rm EW_\rm HI(b)$ in $z\lesssim2$ galaxies, and supports the idea that the CGM profile does not evolve with redshift.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
