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CCAT is a 25 meter submm telescope proposed to be built at 5600 meters elevation on Cerro Chajnantor overlooking the ALMA site in northern Chile. The CCAT site is the best submm site that is accessible by truck, so that with its large aperture, exceptionally good surface accuracy (~17 µm rms total wavefront error, WFE), state-of-theart instrumentation and large (≥20 arcmin) field-of-view (FoV) CCAT will deliver unsurpassed point source sensitivity and mapping speeds across the submm telluric windows. Our primary science goals are: (1) to trace the obscurred star formation (SF) history of the Universe through multicolor submm surveys of 100's deg² on the sky followed up by spectroscopy to characterize the energy sources in dusty SF galaxies; (2) to measure and characterize the SF process in the Milky Way galaxy and nearby resolved galaxies through submm spectroscopic and dust continuum surveys; and (3) to probe galaxy cluster astrophysics through the Sunyaev-Zeldovich (SZ) effect. [ABSTRACT FROM AUTHOR]

Atomic fine-structure line emission is a major cooling process in the interstellar medium (ISM). In particular the [C II] 158 µm line is one of the dominant cooling lines in photon-dominated regions (PDRs). However, it is not confined to PDRs only but can also originate from the ionized gas closely surrounding young massive stars. Here we discuss the question how much of the [C II] emission in the nucleus of the nearby spiral galaxy IC 342 is contributed by PDRs and by the ionized gas. Particularly the correlation of the [C II] line with the also observed [N II] 205 µm emission line coming exclusively from the H II regions is investigated. The emission coming from the ionized gas shows a kinematic component in addition to the general Doppler signature of the molecular gas. We discuss how this requires an adaptation of our understanding of the geometrical structure of the nucleus of IC 342. Applying predictions from numerical models of H II and PDR regions to derive the contribution from the ionized phase to the total [C II] emission we find that 30-60% of the observed [C II] intensity stems from the ionized gas if both phases contribute. [ABSTRACT FROM AUTHOR]

This paper describes the Heterodyne Instrument for the Far-Infrared (HIFI) to be launched onboard of ESA's Herschel Space Observatory, by 2008. The instrument is designed to be electronically tunable over a wide and continuous frequency range in the Far Infrared, with velocity resolutions better than 0.1 kms-1 and a high sensitivity. This will allow detailed investigations of a wide variety of astronomical sources, ranging from solar system objects, star formation regions to nuclei of galaxies. The instrument comprises 5 frequency bands covering 480-1150 GHz with SIS mixers and a sixth dual frequency band, for the 1410-1910 GHz range, with Hot Electron Bolometer Mixers (HEB). The Local Oscillator (LO) subsystem consists of a Ka-band synthesizer followed by 14 chains of frequency multipliers, 2 chains for each frequency band. A pair of Auto-Correlators and a pair of Acousto-Optic spectrometers process the two IF signals from the dual-polarization front-ends to provide instantaneous frequency coverage of 4 GHz, with a set of resolutions (140 kHz to 1 MHz), better than <0.1 kms-1. After a successful qualification program, the flight instrument entered the testing phase. We will also report on the first pre-flight test and calibration results together with the expected in-flight performance. [ABSTRACT FROM AUTHOR]

Based on [Ci] (1-0) observations and complementary Hi, 12/13CO (1-0), 12CO (2-1) and [Cii] data we estimated the column density and fraction of molecular hydrogen in GMCs along the major axis of the galaxy M33. We found that on average 75%±14% of the hydrogen is in molecular form. Roughly 40-45% of the H2 is both traced by [CII] and CO, while ~15% by the [Ci] lines. The found CO-dark H2 gas fractions are within the predictions by Wolfire et al. (2010) for a half solar metallicity, Z = 0.5Zʘ, as in M33. [ABSTRACT FROM AUTHOR]

The CO N+ Deuterium Observations Receiver (CONDOR) is one of the very few heterodyne receivers operational between 1.25 and 1.53 THz. It has successfully obtained first-light observations on APEX and is currently being modified to fly as the low frequency channel of GREAT on SOFIA. [ABSTRACT FROM AUTHOR]

We present high-angular resolution (10 pc) sub-millimeter observations of the N159W region in the LMC obtained with the NANTEN2 telescope. We observed the 12CO J = 4 → 3, J = 7 → 6, 13CO J = 4 → 3 rotational and the [CI] 609 μm and [CI] 370 μm fine-structure transitions toward this region. We detected the [CI] 370 μm and 13CO J = 4 → 3 transitions for the first time in the LMC. [ABSTRACT FROM AUTHOR]

Studying molecular gas in the central regions of the star burst galaxies NGC4945 and Circinus enables us to characterize the physical conditions in these starbursts and compare them with previous studies of local and high-z galaxies. Using the new NANTEN2 4 m sub-millimeter telescope on Pampa La Bola, Chile, we observed for the first time CO 4-3 and [CI] 1-0 at the centers of both galaxies at linear scales of about 700 pc. We find that the centers of NGC4945 and Circinus are very [CI] bright objects, exhibiting [CI] 1-0 luminosities of 91 and 67 Kkms-1 kpc², respectively. The [CI] 1-0/CO 4-3 integrated intensity rations show high values of about 1.2 in NGC 4945 and 2.8 in Circinus. In both galaxies, the estimated total [CI] cooling intensity of both fine structure transitions is stronger by factors of ~1-3 compared to the total CO cooling intensity. The CO/C abundance ratios are 0.2-2. Similarly low values are found in Galactic translucent clouds (Mookerjea et al. 2006). [ABSTRACT FROM AUTHOR]