CYBERSKA

 A Cyberinfrastructure platform to meet the needs of data intensive radio astronomy on route to the SKA

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  • Low Surface Brightness Galaxies in the SDSS: the link between environment, star-forming properties...

Low Surface Brightness Galaxies in the SDSS: the link between environment, star-forming properties and AGN

http://arxiv.org/abs/1007.4014

Using the Sloan Digital Sky Survey (SDSS) data release 4 (DR 4), we investigate the spatial distribution of low and high surface brightness galaxies (LSBs and HSBs, respectively). In particular, we focus our attention on the influence of interactions between galaxies on the star formation strength in the redshift range $0.01 < z < 0.1$. With cylinder counts and projected distance to the first and fifth-nearest neighbor as environment tracers, we found that LSBs tend to have a lack of companions compared to HSBs at small scales ($<2$ Mpc). Regarding the interactions, we have evidence that the fraction of LSBs with strong star formation activity increases when the neighbor is closer than $r_{p}/r_{90} \sim 4$. The intensity of the effect of the interaction on the star formation strength, measured by the average value of the birthrate parameter $b$, seems to be stronger for HSBs than for LSBs. The analysis of our population of LSBs and HSBs hosting an AGN show that, regardless of the mass range, the fraction of LSBs having an AGN is lower than the corresponding fraction of HSBs with an AGN. This result, and those concerning the star-forming properties of LSBs as a function of the environment, fit with the scenario proposed by some authors where, below a given threshold of mass density, LSB disks are unable to propagate instabilities, preventing the massive central black hole of galaxies from being fed and activated. Our results suggest that, rather than being a condition for their survival and evolution, isolation of LSBs is more connected with their formation scenario.