COS-Halos Dataset

This document describes the COS-Halos dataset.

Sources

The COS-Halos Survey is a set of HST/COS (Tumlinson et al. (2013)) and Keck/HIRES spectra (Werk et al. (2013)) for the analysis of the circumgalactic medium of z~0.2 galaxies. The quasars are a set of sources from the SDSS with zem ~ 0.3 to 1. and bright in the FUV.

Meta Data

The additional meta data are from Table 1 and include the following for the HST/COS rows.

Key Type Description
m_FUV float FUV magnitude from GALEX
t_G130M float Exposure time (sec) for the G130M grating
t_G160M float Exposure time (sec) for the G160M grating
Visit str Visit ID(s)

Use pyigm to access the measurements from the COS-Halos survey.

Spectra

The HST/COS spectra are wavelength and flux calibrated spectra using CALCOS and then coadded with proprietary code (see Tumlinson et al. 2013).

The Keck/HIRES spectra are standard HIRedux reductions (see Werk et al. 2013). These spectra are normalized.