CLASSY IV: Exploring UV diagnostics of the interstellar medium in local high-$z$ analogs at the dawn of the JWST era

Understand

The COS Legacy Archive Spectroscopic SurveY (CLASSY) HST/COS treasury program provides the first high-resolution spectral catalogue of 45 local high-z analogues in the UV (1200-2000\AA) to investigate their stellar and gas properties.

• We present a toolkit of UV interstellar medium (ISM) diagnostics, analyzing the main emission lines of CLASSY spectra (i.e., NIV]$\lambda\lambda$1483,87, CIV$\lambda\lambda$1548,51, HeII$\lambda$1640, OIII]$\lambda\lambda$1661,6, SiIII]$\lambda\lambda$1883,92, CIII]$\lambda\lambda$1907,9).
• Specifically, we focus our investigation on providing accurate diagnostics for reddening, electron density and temperature, gas-phase metallicity and ionization parameter, taking into account the different ionization zones of the ISM.
• We calibrate our UV toolkit using well-known optical diagnostics, analyzing archival optical spectra for all the CLASSY targets.