The physical properties of galactic winds are one of the keys to understand galaxy formation and evolution .
These properties can be constrained thanks to background quasar lines of sight ( LOS ) passing near star-forming galaxies ( SFGs ) .
We present the first results of the MusE GAs FLOw and Wind ( MEGAFLOW ) survey obtained of 2 quasar fields which have 8 Mg ii absorbers of which 3 have rest-equivalent width greater than 0.8 Å .
With the new Multi Unit Spectroscopic Explorer ( MUSE ) spectrograph on the Very Large Telescope ( VLT ) , we detect 6 ( 75 \% ) Mg ii host galaxy candidates withing a radius of 30 \arcsec from the quasar LOS .
Out of these 6 galaxy–quasar pairs , from geometrical arguments , one is likely probing galactic outflows , two are classified as “ ambiguous ” , two are likely probing extended gaseous disks and one pair seems to be a merger .
We focus on the wind - pair and constrain the outflow using a high resolution quasar spectra from Ultraviolet and Visual Echelle Spectrograph ( UVES ) .
Assuming the metal absorption to be due to gas flowing out of the detected galaxy through a cone along the minor axis , we find outflow velocities of the order of \approx 150 { km s } ^ { -1 } ( i.e .
smaller than the escape velocity ) with a loading factor , \eta = \dot { M } _ { out } / SFR , of \approx 0.7 .
We see evidence for an open conical flow , with a low-density inner core .
In the future , MUSE will provide us with about 80 multiple galaxy - quasar pairs in two dozen fields .