From Interstellar Clouds to Star-Forming Galaxies: Universal Processes? Proceedings IAU Symposium No. 315, 2015 P. Jablonka, Ph. Andr´ e & F. van der Tak, eds. c  International Astronomical Union 2016 doi:10.1017/S1743921316007201 High-J CO Intensity Measurements for Galaxies Observed by the Herschel FTS Julia Kamenetzky 1 , Naseem Rangwala 2 , Jason Glenn 3 , Philip Maloney 3 and Alex Conley 3 1 Steward Observatory, University of Arizona, Tucson, AZ, U.S. email: jkamenetzky@as.arizona.edu 2 NASA Ames Research Center, Mountain View, CA, U.S. 3 Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO, U.S. Abstract. Molecular gas is the raw material for star formation and is commonly traced by the carbon monoxide (CO) molecule. The atmosphere blocks all but the lowest-J transitions of CO for observatories on the ground, but the launch of the Herschel Space Observatory revealed the CO emission of nearby galaxies from J = 4−3 to J = 13−12. Herschel showed that mid- and high-J CO lines in nearby galaxies are emitted from warm gas, accounting for approximately 10% of the molecular mass, but the majority of the CO luminosity. The energy budget of this warm, highly-excited gas is a significant window into the feedback interactions among molecular gas, star formation, and galaxy evolution. Likely, mechanical heating is required to explain the excitation. Such gas has also been observed in star forming regions within our galaxy. We have examined all ∼300 spectra of galaxies from the Herschel Fourier Transform Spec- trometer and measured line fluxes or upper limits for the CO J = 4 − 3 to J = 13 − 12, [CI], and [NII] 205 micron lines in ∼200 galaxies, taking systematic effects of the FTS into account. We will present our line fitting method, illustrate trends available so far in this large sample, and preview the full 2-component radiative transfer likelihood modeling of the CO emission using an illustrative sample of 20 galaxies, including comparisons to well-resolved galactic regions. This work is a comprehensive study of mid- and high-J CO emission among a variety of galaxy types, and can be used as a resource for future (sub)millimeter studies of galaxies with ground-based instruments. Keywords. galaxies: ISM – ISM: molecules – submillimeter 1. Introduction Molecular gas is the raw material for star formation, and it is also influenced by the ongoing processes of star formation, life, and death. This work focuses on CO as a tracer of molecular gas, specifically the new view of the high-J lines (up to J = 13-12) afforded to us by the Herschel Fourier Transform Spectrometer. The atmosphere blocks all but the lowest-J transitions of CO for observatories on the ground, but the launch of the Herschel Space Observatory revealed the CO emission of nearby galaxies from J = 4-3 to J = 13-12. The early science results from the Herschel demonstrated that the high-J emission from CO was significantly higher than predicted by standard, T kin < 100 K molecular gas described by the low-J lines in the nearby starburst galaxy M82 (Panuzzo et al. 2010). Subsequent studies, such as Kamenetzky et al. (2014) and references therein, found this was true for a variety of galaxies, shown in Figure 1. 26 https://www.cambridge.org/core/terms. https://doi.org/10.1017/S1743921316007201 Downloaded from https://www.cambridge.org/core. IP address: 54.70.40.11, on 25 May 2019 at 02:36:31, subject to the Cambridge Core terms of use, available at