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		| Paper: | 
		Simulations of Long-Lived Double-Barred Galaxies | 
	 
	
		| Volume: | 
		419, Galaxy Evolution: Emerging Insights and Future Challenges | 
	 
	
		| Page: | 
		153 | 
	 
	
		| Authors: | 
		Shen, J.; Debattista, V. P. | 
	 
	
	
		| Abstract: | 
		Many barred galaxies harbor small-scale secondary bars in the center.  The evolution of such double-barred galaxies is still not well understood, partly because of a lack of realistic N-body models with which to study them. Here we report the generation of such systems in the presence of rotating pseudobulges. We demonstrate with high mass and force resolution collisionless N-body simulations that long-lived secondary bars can form spontaneously without requiring gas, contrary to previous claims. We find that secondary bars rotate faster than primary ones. The rotation is not rigid: the secondary bars pulsate, with their amplitude and pattern speed oscillating as they rotate through the primary bars. This self-consistent study supports previous work based on orbital analysis in the potential of two rigidly rotating bars. We also characterize the density and kinematics of the N-body simulations of the double-barred galaxies, compare with observations to achieve a better understanding of such galaxies. The pulsating nature of secondary bars may have important implications for understanding the central region of double-barred galaxies. | 
	 
	
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