|   | 
				
					
	
		  | 
	 
	
		| Paper: | 
		The Photo Dissociation Region Toolbox | 
	 
	
		| Volume: | 
		394, Astronomical Data Analysis Software and Systems (ADASS) XVII | 
	 
	
		| Page: | 
		654 | 
	 
	
		| Authors: | 
		Pound, M.W.; Wolfire, M.G. | 
	 
	
	
		| Abstract: | 
		Ultraviolet photons from O and B stars strongly influence the structure and emission spectra of the interstellar medium. The UV photons energetic enough to ionize hydrogen (hν > 13.6 eV) will create the H II region around the star, but lower energy UV photons escape. These far-UV photons (6 eV < hν < 13.6 eV) are still energetic enough to photodissociate molecules and to ionize low ionization-potential atoms such as carbon, silicon, and sulfur. They thus create a photodissociation region (PDR) just outside the H II region. In aggregate, these PDRs dominates the heating and cooling of the neutral interstellar medium. As part of the Web Infrared Tool Shed (WITS) we have developed a web tool, called the PDR Toolbox, that allows users to determine the physical parameters of a PDR from a set of spectral line observations. Typical observations of both Galactic and extragalactic PDRs come from groundbased millimeter and submillimeter telescopes such as CARMA or the CSO, or space-based telescopes such as Spitzer, ISO, SOFIA, and Herschel. Given a set of observations of spectral line intensities, PDR Toolbox will compute best-fit FUV incident intensity and cloud density based on our published models of PDR emission. The PDR Toolbox is available at http://dustem.astro.umd.edu/pdrt. | 
	 
	
		| 
			
			
		 | 
	 
	
		  | 
	 
 
					 
				 | 
				  |