We present two-dimensional gaseous kinematics of the inner 1.1 \times 1.6 kpc ^ { 2 } of the Seyfert 2 galaxy NGC 2110 , from optical spectra ( 5600–7000 Å ) obtained with the GMOS integral field spectrograph on the Gemini South telescope at a spatial resolution of \approx 100 pc .
Gas emission is observed over the whole field-of-view , with complex – and frequently double – emission-line profiles .
We have identified four components in the emitting gas , according to their velocity dispersion ( \sigma ) , which we refer to as : ( 1 ) warm gas disk ( \sigma = 100–220 km s ^ { -1 } ) ; ( 2 ) cold gas disk ( \sigma = 60–90 km s ^ { -1 } ) ; ( 3 ) nuclear component ( \sigma = 220–600 km s ^ { -1 } ) ; and ( 4 ) northern cloud ( \sigma = 60–80 km s ^ { -1 } ) .
Both the cold and warm disk components are dominated by rotation and have similar gas densities , but the cold gas disk has lower velocity dispersions and reaches higher rotation velocities .
We attribute the warm gas disk to a thick gas layer which encompasses the cold disk as observed in some edge-on spiral galaxies .
After subtraction of a rotation model from the cold disk velocity field , we observe excess blueshifts of \approx 50 km s ^ { -1 } in the far side of the galaxy ( NE ) as well as similar excess redshifts in the near side ( SW ) .
These residuals can be interpreted as due to nuclear inflow in the cold gas , with an estimated ionized gas mass inflow rate of \phi \approx 2.2 \times 10 ^ { -2 } M _ { \odot } yr ^ { -1 } .
We have also subtracted a rotating model from the warm disk velocity field and found excess blueshifts of \approx 100 km s ^ { -1 } to the SW of the nucleus and excess redshifts of \approx 40 km s ^ { -1 } to the NE , which we attribute to gas disturbed by an interaction with a nuclear spherical outflow .
This nuclear outflow is the origin of the nuclear component observed within the inner 300 pc and it has a mass outflow rate of 0.9 M _ { \odot } yr ^ { -1 } .
In a region between 1″ and 4″ north of the nucleus , which shows strong X-ray and [ O III ] \lambda 5007Å emission , we find a new low \sigma component of ionized gas which we attribute to a high latitude cloud photoionized by the nuclear source .
The identification of the 4 distinct kinematic components has clarified the nature of the apparent asymmetry in the rotation curve of the galaxy pointed out in previous studies : it results from the dominance of different components to the south and north of the nucleus .
We conclude that a comprehensive two-dimensional coverage of the kinematics and geometry of the nuclear gas around the AGN is necessary to reveal the different processes at play , such as its feeding – via the cold inflowing gas – and the feedback , via the warm gas outflows .