  Evidence has been accumulated on the existence of a thermal-like component
during the prompt phase of GRBs. This component, often associated with the GRB
jet's photosphere, is usually subdominant compared to a much stronger
non-thermal one. The prompt emission of Fermi GRB 131014A provides a unique
opportunity to study this thermal-like component. Indeed, the thermal emission
in GRB 131014A is much more intense than in other GRBs and a pure thermal
episode is observed during the initial 0.16 s. The thermal-like component cools
monotonically during the first second while the non-thermal emission kicks off.
The intensity of the non-thermal component progressively increases until being
energetically dominant at late time. This is a perfect scenario to disentangle
the thermal component from the non-thermal one. A low-energy spectral index of
+0.6 better fit the thermal component than the typical index value +1
corresponding to a pure Planck function. The non-thermal component is
adequately fitted with a Band function whose low and high energy power law
indices are ~-0.7 and <~-3, respectively; this is also statistically equivalent
to a cutoff power law with a ~-0.7 index. This is in agreement with our
previous results. Finally, a strong correlation is observed between the
time-resolved luminosity of the non-thermal component, L$_i^{nTh}$, and its
corresponding rest frame spectral peak energy, E$_{peak,i}^{rest,nTh}$, with a
slope similar to the one reported in our previous articles. Assuming this
relation to be universal for all GRBs we estimate a redshift of ~1.55 for GRB
131014A that is a typical value for long GRBs. These observational results are
consistent with the models in which the non-thermal emission is produced well
above the GRB jet photosphere but they may also be compatible with other
scenarios (e.g., dissipative photosphere) that are not discussed in this
article.
