We present a multi-wavelength integral field spectroscopic ( IFS ) study of the low-z luminous infrared galaxy IRAS F11506-3851 ( ESO 320-G030 ) on the basis of the moderate spectral resolution observations ( R \sim 3400 - 4000 ) taken with the VIMOS and SINFONI instruments at the ESO VLT .
The morphology and the 2D kinematics of the gaseous ( neutral and ionized ) and stellar components have been mapped in the central regions ( < 3 kpc ) using the NaD \lambda \lambda 5890,5896 \AA absorption doublet , the H \alpha \lambda 6563 \AA line , and the near-IR CO ( 2-0 ) \lambda 2.293 \mu m and CO ( 3-1 ) \lambda 2.322 \mu m bands . The kinematics of the ionized gas and the stars are dominated by rotation , with large observed velocity amplitudes ( \Delta V ( H \alpha ) = 203 \pm 4 km s ^ { -1 } ; \Delta V ( CO ) = 188 \pm 11 km s ^ { -1 } , respectively ) and centrally peaked velocity dispersion maps ( \sigma _ { c } ( H \alpha ) = 95 \pm 4 km s ^ { -1 } and \sigma _ { c } ( CO ) = 136 \pm 20 km s ^ { -1 } ) .
The stars lag behind the warm gas and represent a dynamically hotter system , as indicated by the observed V/ \sigma ratios ( 4.5 and 2.4 for the gas and the stars , respectively ) .
Thanks to these IFS data we have disentangled the contribution of the stars and the interstellar medium to the NaD feature , finding that it is dominated by absorption of neutral gas clouds in the ISM ( \sim 2/3 of total EW ) .
The 2D kinematics of the neutral gas shows a complex structure dominated by two main components .
On the one hand , the thick slowly rotating disk ( \Delta V ( NaD ) = 81 \pm 12 km s ^ { -1 } ) lags significantly compared to the ionized gas and the stars , and it has an irregular and off-center velocity dispersion map ( with values of up to \sim 150 km s ^ { -1 } at \sim 1 kpc from the nucleus ) .
On the other hand , a kpc-scale neutral gas outflow perpendicular to the disk , as is revealed by the large blueshifted velocities ( in the range 30 - 154 km s ^ { -1 } ) observed along the galaxy ’ s semi-minor axis ( within the inner 1.4 kpc ) . On the basis of a simple free wind scenario , we derive an outflowing mass rate ( \dot { M _ { w } } ) in neutral gas of about 48 M _ { \odot } yr ^ { -1 } .
Although this implies a global mass loading factor ( i.e. , \eta = \dot { M _ { w } } /SFR ) of \sim 1.4 , the 2D distribution of the ongoing SF as traced by the H \alpha emission map suggests a much larger value of \eta associated with the inner regions ( R < 200 pc ) , where the current observed star formation ( SF ) represents only \sim 3 percent of the total .
However , the relatively strong emission by SNe in the central regions , as traced by the [ FeII ] emission , indicates recent strong episodes of SF .
Therefore , our data show clear evidence of the presence of a strong outflow with large loading factors associated with the nuclear regions , where recent starburst activity took place about 7 Myr ago , although it currently shows relatively modest SF levels .
All together these results strongly suggest that we are witnessing ( nuclear ) quenching due to SF feedback in IRAS F11506-3851 .
However , the relatively large mass of molecular gas detected in the nuclear region via the H _ { 2 } 1 -0 S ( 1 ) line suggests that further episodes of SF may take place again .