Physical Sciences and Mathematics Commons^™

Resolving The Far-Ir Line Deficit: Photoelectric Heating And Far-Ir Line Cooling In Ngc 1097 And Ngc 4559, Kevin V. Croxall, J. D. Smith, M. G. Wolfire, H. Roussel, K. M. Sandstrom, B. T. Draine, G. Aniano, D. A. Dale, L. Armus, P. Beirão, G. Helou, A. D. Bolatto, P. N. Appleton, B. R. Brandl, Daniela Calzetti, A. F. Crocker, M. Galametz, B. A. Groves, C.-N. Hao, L. K. Hunt, B. D. Johnson, R, C, Kennicutt, J. Koda, O. Krause, Y. Li, S. E. Meidt, E. J. Murphy, N. Rahman, H.-W. Rix, M. Sauvage, E. Schinnerer, F. Walter, C. D. Wilson

Daniela Calzetti

The physical state of interstellar gas and dust is dependent on the processes which heat and cool this medium. To probe heating and cooling of the ISM over a large range of infrared surface brightness, on sub-kiloparsec scales, we employ line maps of [C \ii] 158 $\mu$m, [O \one] 63 $\mu$m, and [N \ii] 122 $\mu$m in NGC 1097 and NGC 4559, obtained with the PACS spectrometer onboard {\it Herschel}. We matched new observations to existing Spitzer-IRS data that trace the total emission of polycyclic aromatic hydrocarbons (PAHs). We confirm at small scales in these galaxies that the canonical measure …