  This work presents a re-analysis of the spectroscopic phase-curve
observations of the ultra hot Jupiter WASP-103 b obtained by the Hubble Space
Telescope (HST) and the Spitzer Telescope. Traditional 1D and unified 1.5D
spectral retrieval techniques are employed, allowing to map the thermal
structure and the abundances of trace gases in this planet as a function of
longitude. On the day-side, the atmosphere is found to have a strong thermal
inversion, with indications of thermal dissociation traced by continuum H-
opacity. Water vapor is found across the entire atmosphere but with depleted
abundances of around 1e-5, consistent with the thermal dissociation of this
molecule. Regarding metal oxide and hydrides, FeH is detected on the hot-spot
and the day-side of WASP-103 b, but TiO and VO are not present in detectable
quantities. Carbon-bearing species such as CO and CH4 are also found, but since
their detection is reliant on the combination of HST and Spizer, the retrieved
abundances should be interpreted with caution. Free and Equilibrium chemistry
retrievals are overall consistent, allowing to recover robust constraints on
the metallicity and C/O ratio for this planet. The analyzed phase-curve data
indicates that the atmosphere of WASP-103 b is consistent with solar elemental
ratios.
