We investigate spatially resolved specific star formation rate ( SSFR ) in the inner \sim 40 pc for a nearby Seyfert 2 galaxy , M51 ( NGC 5194 ) by analyzing spectra obtained with the Hubble Space Telescope ( HST ) Space Telescope Imaging Spectrograph ( STIS ) .
We present 24 radial spectra measured along the STIS long slit in M51 , extending \sim 1 \arcsec from the nucleus ( i.e. , -41.5 pc to 39.4 pc ) .
By the simple stellar population synthesis , the stellar contributions in these radial optical spectra are modeled .
Excluding some regions with zero young flux fraction near the center ( from -6 pc to 2 pc ) , we find that the mean flux fraction of young stellar populations ( younger than 24.5 Myr ) is about 9 % , the mean mass fraction is about 0.09 % .
The young stellar populations are not required in the center inner \sim 8 pc in M51 , suggesting a possible SSFR suppression in the circumnuclear region ( \sim 10 pc ) from the feedback of active galactic nuclei ( AGNs ) .
The radial distribution of SSFR in M51 is not symmetrical with respect to the long slit in STIS .
This unsymmetrical SSFR distribution is possibly due to the unsymmetrical AGN feedback in M51 , which is related to its jet .