Large-Scale CO Maps of the Lupus Molecular Cloud Complex

Fully sampled degree-scale maps of the 13CO 2-1 and CO 4-3 transitions toward three members of the Lupus Molecular Cloud Complex - Lupus I, III, and IV - trace the column density and temperature of the molecular gas. Comparison with IR extinction maps from the c2d project requires most of the gas to have a temperature of 8-10 K. Estimates of the cloud mass from 13CO emission are roughly consistent with most previous estimates, while the line widths are higher, around 2 km/s. CO 4-3 emission is found throughout Lupus I, indicating widespread dense gas, and toward Lupus III and IV. Enhanced line widths at the NW end and along the edge of the B228 ridge in Lupus I, and a coherent velocity gradient across the ridge, are consistent with interaction between the molecular cloud and an expanding HI shell from the Upper-Scorpius subgroup of the Sco-Cen OB Association. Lupus III is dominated by the effects of two HAe/Be stars, and shows no sign of external influence. Slightly warmer gas around the core of Lupus IV and a low line width suggest heating by the Upper-Centaurus-Lupus subgroup of Sco-Cen, without the effects of an HI shell.Comment: 54 pages, 27 figures, 5 tables. To appear in ApJS. Preprint also available (with full-size figures) from http://www.astro.ex.ac.uk/people/nfht/publications.html Datacubes available from http://www.astro.ex.ac.uk/people/nfht/resources.htm

[CII] At 1 < z < 2: Observing Star Formation in the Early Universe with Zeus (1 and 2)

We report the detection of the [CII] 158 micron fine structure line from six submillimeter galaxies with redshifts between 1.12 and 1.73. This more than doubles the total number of [CII] 158 micron detections reported from high redshift sources. These observations were made with the Redshift(z) and Early Universe Spectrometer(ZEUS) at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii between December 2006 and March 2009. ZEUS is a background limited submm echelle grating spectrometer (Hailey-Dunsheath 2009). Currently we are constructing ZEUS-2. This new instrument will utilize the same grating but will feature a two dimensional transition-edge sensed bolometer array with SQUID multiplexing readout system enabling simultaneous background limited observations in the 200, 340,450 and 650 micron telluric windows. ZEUS-2 will allow for long slit imaging spectroscopy in nearby galaxies and a [CII] survey from z 0.25 to 2.5

Mid-J CO Emission From NGC 891: Microturbulent Molecular Shocks in Normal Star Forming Galaxies

We have detected the CO(6-5), CO(7-6), and [CI] 370 micron lines from the nuclear region of NGC 891 with our submillimeter grating spectrometer ZEUS on the CSO. These lines provide constraints on photodissociation region (PDR) and shock models that have been invoked to explain the H_2 S(0), S(1), and S(2) lines observed with Spitzer. We analyze our data together with the H_2 lines, CO(3-2), and IR continuum from the literature using a combined PDR/shock model. We find that the mid-J CO originates almost entirely from shock-excited warm molecular gas; contributions from PDRs are negligible. Also, almost all the H_2 S(2) and half of the S(1) line is predicted to emerge from shocks. Shocks with a pre-shock density of 2x10^4 cm^-3 and velocities of 10 km/s and 20 km/s for C-shocks and J-shocks, respectively, provide the best fit. In contrast, the [CI] line emission arises exclusively from the PDR component, which is best parameterized by a density of 3.2x10^3 cm^-3 and a FUV field of G_o = 100 for both PDR/shock-type combinations. Our mid-J CO observations show that turbulence is a very important heating source in molecular clouds, even in normal quiescent galaxies. The most likely energy sources for the shocks are supernovae or outflows from YSOs. The energetics of these shock sources favor C-shock excitation of the lines.Comment: 18 pages, 2 figures, 6 tables, accepted by Ap

Detection of the 13CO(J=6-5) Transition in the Starburst Galaxy NGC 253

We report the detection of 13CO(J=6-5) emission from the nucleus of the starburst galaxy NGC 253 with the redshift (z) and Early Universe Spectrometer (ZEUS), a new submillimeter grating spectrometer. This is the first extragalactic detection of the 13CO(J=6-5) transition, which traces warm, dense molecular gas. We employ a multi-line LVG analysis and find ~ 35% - 60% of the molecular ISM is both warm (T ~ 110 K) and dense (n(H2) ~ 10^4 cm^-3). We analyze the potential heat sources, and conclude that UV and X-ray photons 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.Comment: 4 pages, 2 figures, accepted by ApJ Letter

Detection of the 158 micron [CII] Transition at z=1.3: Evidence for a Galaxy-Wide Starburst

We report the detection of 158 micron [CII] fine-structure line emission from MIPS J142824.0+352619, a hyperluminous (L_IR ~ 10^13 L_sun) starburst galaxy at z=1.3. The line is bright, and corresponds to a fraction L_[CII]/L_FIR = 2 x 10^-3 of the far-IR (FIR) continuum. The [CII], CO, and FIR continuum emission may be modeled as arising from photodissociation regions (PDRs) that have a characteristic gas density of n ~ 10^4.2 cm^-3, and that are illuminated by a far-UV radiation field ~10^3.2 times more intense than the local interstellar radiation field. The mass in these PDRs accounts for approximately half of the molecular gas mass in this galaxy. The L_[CII]/L_FIR ratio is higher than observed in local ULIRGs or in the few high-redshift QSOs detected in [CII], but the L_[CII]/L_FIR and L_CO/L_FIR ratios are similar to the values seen in nearby starburst galaxies. This suggests that MIPS J142824.0+352619 is a scaled-up version of a starburst nucleus, with the burst extended over several kiloparsecs.Comment: 6 pages, 3 figures, accepted by ApJ Letter

CCAT-prime: Science with an Ultra-widefield Submillimeter Observatory at Cerro Chajnantor

We present the detailed science case, and brief descriptions of the telescope design, site, and first light instrument plans for a new ultra-wide field submillimeter observatory, CCAT-prime, that we are constructing at a 5600 m elevation site on Cerro Chajnantor in northern Chile. Our science goals are to study star and galaxy formation from the epoch of reionization to the present, investigate the growth of structure in the Universe, improve the precision of B-mode CMB measurements, and investigate the interstellar medium and star formation in the Galaxy and nearby galaxies through spectroscopic, polarimetric, and broadband surveys at wavelengths from 200 um to 2 mm. These goals are realized with our two first light instruments, a large field-of-view (FoV) bolometer-based imager called Prime-Cam (that has both camera and an imaging spectrometer modules), and a multi-beam submillimeter heterodyne spectrometer, CHAI. CCAT-prime will have very high surface accuracy and very low system emissivity, so that combined with its wide FoV at the unsurpassed CCAT site our telescope/instrumentation combination is ideally suited to pursue this science. The CCAT-prime telescope is being designed and built by Vertex Antennentechnik GmbH. We expect to achieve first light in the spring of 2021.Comment: Presented at SPIE Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX, June 14th, 201

Detection of the 205 um [NII] Line from the Carina Nebula

We report the first detection of the 205 um 3P1 - 3P0 [NII] line from a ground-based observatory using a direct detection spectrometer. The line was detected from the Carina star formation region using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) on the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) at South Pole. The [NII] 205 um line strength indicates a low-density (n ~ 32 cm^-3 ionized medium, similar to the low-density ionized halo reported previously in its [OIII] 52 and 88 um line emission. When compared with the ISO [CII] observations of this region, we find that ~27% of the [CII] line emission arises from this low-density ionized gas, but the large majority ~ 73% of the observed [CII] line emission arises from the neutral interstellar medium. This result supports and underpins prior conclusions that most of the observed [CII] 158 um line emission from Galactic and extragalactic sources arises from the warm, dense photodissociated surfaces of molecular clouds. The detection of the [NII] line demonstrates the utility of Antarctic sites for THz spectroscopy.Comment: 8 pages, 2 figures. To appear in the Astrophysical Journal Letter

The performance of TripleSpec at Palomar

We report the performance of Triplespec from commissioning observations on the 200-inch Hale Telescope at Palomar Observatory. Triplespec is one of a set of three near-infrared, cross-dispersed spectrographs covering wavelengths from 1 - 2.4 microns simultaneously at a resolution of ~2700. At Palomar, Triplespec uses a 1×30 arcsecond slit. Triplespec will be used for a variety of scientific observations, including moderate to high redshift galaxies, star formation, and low mass stars and brown dwarfs. When used in conjunction with an externally dispersed interferometer, Triplespec will also detect and characterize extrasolar planets