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Session 48 - Spiral & Field Galaxies.
Display session, Tuesday, January 16
North Banquet Hall, Convention Center
We use deep B-band CCD images of the galaxy NGC 5248 to map its spiral structure to a surface brightness of 27.5 magnitudes / sq. arcsec. The two main spiral arms clearly continue well beyond the presumed outer Lindblad resonance. Measurements of the arm/interarm contrast show that the strenths of the main arms reach local maxima near the co-rotation resonance, as well as near the outermost of our detected features. Likewise, the pitch of the main arms varies with radius, so that the spiral features become nearly circular both near co-rotation as well as near the outer edge. Limited color information suggests the strong outer spiral features are composed of a relatively young stellar population.
Program listing for Tuesday