Which galaxies host bars and disks? A study of the Coma Cluster.

Figure Caption: Optical bar fraction of strong (solid black line) and weak+strong (dashedblue line) as a function of the galaxy absolute magnitude in r band (left panel)and galaxy mass (right panel). Red points and black circles represent the strong and w
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(2010)The Astrophysical Journal Letters, Volume 711, Issue 2, pp. L61-L65

In this work we present a recent study of the bar fraction in the ComaCluster galaxies based on a sample of ~190 galaxies selected from theSloan Digital Sky  Survey Data Release 6 and observed with the Hubble Space Telescope (HST)  Advanced  Camera for Survey  (ACS).The unprecedented resolution of the HST-ACS  images allows us  to explore the presence of bars, detected by visual classification, throughout luminosity range of 9 mag (-23 < Mr < -14), permitting us to study th poor known region  of dwarf galaxies. We find that  bars are hosted bygalaxies in  a tight range of both  luminosities (-22 < Mr  < -17)an masses (109 < M*/Msun < 1011).  This result holds when compared witha sample of  bright/massive field galaxies. In addition,  we find that the  bar fraction  does not  vary  significantly when going from  the center  to the  cluster outskirts,  implying that  cluster environmentplays a second-order role in bar formation/evolution. The shape of the bar fraction distribution with respect  to both luminosity and mass is well matched by the luminosity  distribution of disk galaxies in Coma indicating that bars  are good  tracers  of cold stellar disks.  We discuss the  implications of our results for  the  formation and evolution scenarios of bars and disks.

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