We present two-dimensional ( 2D ) gas kinematics and excitation of the inner 300 pc of the Seyfert galaxy ESO 428-G14 at a sampling of 14 pc ^ { 2 } , from near-infrared spectroscopic observations at R \approx 6000 obtained with the Integral Field Unit of the Gemini Near-Infrared Spectrograph .
From measurements of fluxes and profiles of the emission lines [ Fe ii ] \lambda 1.257 \mu m , Pa \beta , H _ { 2 } \lambda 2.121 \mu m and Br \gamma , we construct 2D maps of line intensities and ratios , radial velocities and velocity dispersions .
Emission lines “ tomography ” is provided by velocity slices obtained across the line profiles , a unique capability of IFUs , which allows the mapping of not only of peak velocities but including also the wings .
We compare these maps with a previously published high spatial resolution radio map and find a tight relation between the radio structure and the emission-line flux distributions and kinematics , revealing that the radio-jet plays a fundamental role not only in shaping the NLR but also in the imprint of its kinematics .
Blueshifts of up to 400 km s ^ { -1 } and velocity dispersions of up to 150 km s ^ { -1 } are observed in association with the radio jet at position angle PA = 129 ^ { \circ } , which is also the PA of the photometric major axis of the galaxy .
We conclude that the radio jet is launched at a small angle relative to the galactic plane , with the NW side slightly oriented toward us .
This angle is small enough for the radio jet to shock and compress the gas in the plane of the galaxy , and for the nuclear continuum to ionize and heat it .
The distinct kinematics and flux distributions observed for the different emission lines suggest different origins for their emission .
The [ Fe ii ] shows the largest blueshifts and velocity dispersions and its flux distribution is concentrated along the jet , while the H _ { 2 } shows the lowest velocity dispersions and has additional flux contribution from regions beyond the jet .
Both X-rays emitted by the active galactic nucleus and shocks produced by the radio jet can excite the H _ { 2 } and [ Fe ii ] emission lines .
We use the 2D velocity dispersion maps to estimate upper limits to the contribution of the radio jet to the excitation of [ Fe ii ] and H _ { 2 } which may reach 90 % for [ Fe ii ] and 80 % for H _ { 2 } in the jet region .
The [ Fe ii ] /Pa \beta emission-line ratios and the association of the [ Fe ii ] flux distribution and kinematics with the radio structure supports a stronger contribution of the radio jet to the [ Fe ii ] excitation than to that of H _ { 2 } .
In the regions beyond the jet the observations favor X-ray excitation .