A Wide-Field View of Leo II – A Structural Analysis Using the SDSS
نویسندگان
چکیده
Using SDSS I data, we have analysed the stellar distribution of the Leo II dwarf spheroidal galaxy (distance of 233 kpc) to search for evidence of tidal deformation. The existing SDSS photometric catalogue contains gaps in regions of high stellar crowding, hence we filled the area at the centre of Leo II using the DAOPHOT algorithm applied to the SDSS images. The combined DAOPHOTSDSS dataset contains three-filter photometry over a 4× 4 square degree region centred on Leo II. By defining a mask in three-filter colour-magnitude space, we removed the majority of foreground field stars. We have measured the following Leo II structural parameters: a core radius of rc = 2.64± 0.19 arcmin (178± 13 pc), a tidal radius of rt = 9.33± 0.47 arcmin (632± 32 pc) and a total V -band luminosity of LV = (7.4± 2.0)× 10 L⊙ (MV = −9.9± 0.3). Our comprehensive
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