We report the detection of far-infrared (FIR) CO rotational emission from nearby active galactic nuclei (AGN) and starburst galaxies, as well as several merging systems and Ultra-Luminous Infrared Galaxies (ULIRGs). Using Herschel-PACS, we have detected transitions in the J upp = 14 -20 range (λ ∼ 130 -185 µm, ν ∼ 1612 -2300 GHz) with upper limits on (and in two cases, detections of) CO line fluxes up to J upp = 30. The PACS CO data obtained here provide the first well-sampled FIR extragalactic CO Spectral Line Energy Distributions (SLEDs) for this range, and will be an essential reference for future high redshift studies. We find a large range in the overall SLED shape, even amongst galaxies of similar type, demonstrating the uncertainties in relying solely on high-J CO diagnostics to characterize the excitation source of a galaxy. Combining -2our data with low-J line intensities taken from the literature, we present a CO ratio-ratio diagram and discuss its potential diagnostic value in distinguishing excitation sources and physical properties of the molecular gas. The position of a galaxy on such a diagram is less a signature of its excitation mechanism, than an indicator of the presence (or absence) of warm, dense molecular gas. We then quantitatively analyze the CO emission from a subset of the detected sources with Large Velocity Gradient (LVG) radiative transfer models to fit the CO SLEDs. Using both single-component and two-component LVG models to fit the kinetic temperature, velocity gradient, number density and column density of the gas, we derive the molecular gas mass and the corresponding CO-to-H 2 conversion factor, α CO , for each respective source. For the ULIRGs we find α values in the canonical range 0.4 -5 M /(K kms −1 pc 2 ), while for the other objects, α varies between 0.2 and 14. Finally, we compare our best-fit LVG model results with those obtained in previous studies of the same galaxies and comment on any differences.

We have recently detected the [CII] 157.7 µm line in eight star forming galaxies at redshifts 1 to 2 using the redshift(z) Early Universe Spectrometer (ZEUS). Our sample targets star formation dominant sources detected in PAH emission. This represents a significant addition to [CII] observations during the epoch of peak star formation. We have augmented this survey with observations of the [OI] 63 µm line and far infrared photometry from the PACS and SPIRE Herschel instruments as well as Spitzer IRS spectra from the literature showing PAH features. Our sources exhibit above average gas heating efficiency, many with both [OI]/FIR and [CII]/FIR ∼1% or more. The relatively strong [CII] emissionis consistent with our sources being dominated by star formation powered PDRs, extending to kpc scales. We suggest that the star formation mode in these systems follows a Schmidt-Kennicutt law similar to local systems, but at a much higher rate due to molecular gas surface densities 10 to 100 times that of local star forming systems. The source of the high molecular gas surface densities may be the infall of neutral gas from the cosmic web. In addition to the high [CII]/FIR values, we also find high [CII]/PAH ratios and, in at least one source, a cool dust temperature. This source, SWIRE 4-5, bears a resemblance in these diagnostics to shocked regions of Stephan's Quintet, suggesting that another mode of [CII] excitation in addition to normal photoelectric heating may be contributing to the observed [CII] line.

We report the detection of far-IR CO rotational emission from the prototypical Seyfert 2 galaxy NGC 1068. Using Herschel-PACS, we have detected 11 transitions in the J upper = 14 − 30 (E upper /k B = 580 − 2565 K) range, all of which are consistent with arising from within the central 10 ′′ (700 pc). The detected transitions are modeled as arising from 2 different components: a moderate excitation (ME) component close to the galaxy systemic velocity, and a high excitation (HE) component that is blueshifted by ∼80 km s −1 . We employ a large velocity gradient (LVG) model and derive n H2 ∼ 10 5.6 cm −3 , T kin ∼ 170 K, and M H 2 ∼ 10 6.7 M ⊙ for the ME component, and n H2 ∼ 10 6.4 cm −3 , T kin ∼ 570 K, and M H 2 ∼ 10 5.6 M ⊙ for the HE component, although for both components the uncertainties in the density and mass are ±(0.6 − 0.9) dex. Both components arise from denser and possibly warmer gas than traced by low-J CO transitions, and the ME component likely makes a significant contribution to the mass budget in the nuclear region. We compare the CO line profiles with those of other molecular tracers observed at higher spatial and spectral resolution, and find that the ME transitions are consistent with these lines arising in the ∼200 pc diameter ring of material traced by H 2 1-0 S(1) observations. The blueshift of the HE lines may also be consistent with the bluest regions of this H 2 ring, but a better kinematic match is found with a clump of infalling gas ∼40 pc north of the AGN. We consider potential heating mechanisms, and conclude that X-ray or shock heating of both components is viable, while far-UV heating is unlikely. We discuss the prospects of placing the HE component near the AGN, and conclude that while the moderate thermal pressure precludes an association with the ∼1 pc radius H 2 O maser disk, the HE component could potentially be located only a few parsecs more distant from the AGN, and might then provide the N H ∼ 10 25 cm −2 column obscuring the nuclear hard X-rays. Finally, we also report sensitive upper limits extending up to J upper = 50, which place constraints on a previous model prediction for the CO emission from the X-ray obscuring torus.

We report the detection of 13 CO emission from the nucleus of the starburst galaxy NGC 253 with J p 6 r 5 the redshift (z) and Early Universe Spectrometer (ZEUS), a new submillimeter grating spectrometer. This is the first extragalactic detection of the 13 CO transition, which traces warm, dense molecular gas. We employ J p 6 r 5 a multiline LVG analysis and find ≈35%-60% of the molecular interstellar medium is both warm ( K) T ∼ 110 and dense ( cm Ϫ3 ). We analyze the potential heat sources and conclude that ultraviolet and X-ray photons 4 n ∼ 10 H 2 are unlikely to be energetically important. Instead, the molecular gas is most likely heated by an elevated density of cosmic rays or by the decay of supersonic turbulence through shocks. If the cosmic rays and turbulence are created by stellar feedback within the starburst, then our analysis suggests the starburst may be self-limiting.

SuperSpec is an on-chip filter-bank spectrometer designed for wideband moderateresolution spectroscopy at millimeter wavelengths, employing TiN kinetic inductance detectors. SuperSpec technology will enable large-format spectroscopic integral field units suitable for high-redshift line intensity mapping and multi-object spectrographs. In previous results we have demonstrated noise performance in individual detectors suitable for photon noise limited ground-based observations at excellent mm-wave sites. In these proceedings we present the noise performance of a full R ∼ 275 spectrometer measured using deployment-ready RF hardware and software. We report typical noise equivalent powers through the full device of ∼ 3 × 10 −16 W Hz −1/2 at expected sky loadings, which are photon noise dominated. Based on these results, we plan to deploy a six-spectrometer demonstration instrument to the Large Millimeter Telescope in early 2020.