We present an overview of data available for the Ophiuchus and Perseus molecular clouds from ``Phase I'' of the COMPLETE Survey of Star-Forming Regions. This survey provides a range of data complementary to the Spitzer Legacy Program ``From Molecular Cores to Planet Forming Disks.'' Phase I includes: Extinction maps derived from 2MASS near-infrared data using the NICER algorithm; extinction and temperature maps derived from IRAS 60 and 100um emission; HI maps of atomic gas; 12CO and 13CO maps of molecular gas; and submillimetre continuum images of emission from dust in dense cores. Not unexpectedly, the morphology of the regions appears quite different depending on the column-density tracer which is used, with IRAS tracing mainly warmer dust and CO being biased by chemical, excitation and optical depth effects. Histograms of column-density distribution are presented, showing that extinction as derived from 2MASS/NICER gives the closest match to a log-normal distribution as is predicted by numerical simulations. All the data presented in this paper, and links to more detailed publications on their implications are publically available at the COMPLETE website.Comment: Accepted by AJ. Full resolution version available from: http://www.cfa.harvard.edu/COMPLETE/papers/complete_phase1.pd

We present results from 1078 high resolution spectra of 990 stars in the young open cluster NGC 2264, obtained with the Hectochelle multiobject echelle spectrograph on the 6.5m MMT. We confirm 471 stars as members, based on their radial velocity and/or Hα emission. The radial velocity distribution of cluster members is non-Gaussian with a dispersion of σ ≈ 3.5km s −1 . We find a substantial north-south velocity gradient and spatially coherent structure in the radial velocity distribution, similar to that seen in the molecular gas in the region. Our results suggest that there are at least three distinguishable subclusters in NGC 2264, correlated with similar structure seen in 13 CO emission, which is likely to be a remnant of initial structure in this very young cluster. We propose that this substructure is the result of gravitational amplification of initial inhomogeneities during overall collapse to a filamentary distribution of gas and stars, as found in simulations by Burkert & Hartmann (2004).

We have created new dust temperature and column density maps of Perseus, Ophiuchus and Serpens using 60 and 100 µm data from the IRIS recalibration of IRAS data. We describe an optimized method for finding the dust temperature, emissivity spectral index, and optical depth using optical and NIR extinction maps. The creation of these temperature and extinction maps (covering tens of square degrees of molecular clouds) is one of the first results from the ongoing COordinated Molecular Probe Line Extinction Thermal Emission (COMPLETE) Survey of Star Forming regions. However, while the extinctions derived from the IRIS emission maps are globally accurate, we warn that FIR emission is not a good proxy for extinction on the scale of one pixel (∼5 ′ ).In addition to describing the global dust properties of these clouds, we have found two particularly interesting features in the column density and temperature maps. In the Ophiuchus dark cloud complex, the new dust temperature map shows a little known warm (25 K) dust ring with 2 pc diameter. This shell is approximately centered on the B star ρ-Ophiuchus, 1 • north of the well-studied ρ-Oph star-forming cluster. In Perseus, the column density map shows a 10 pc diameter ring, a feature not apparent in the filamentary chain of clouds seen in molecular gas. These rings are further discussed in detail in companion papers to this one.

As the first step of a multi-wavelength investigation into the relationship between young stellar clusters and their environment we present fully-sampled maps in the J=1-0 lines of 13 CO and C 18 O and the J=2-1 line of C 18 O for a selected group of thirty young stellar groups and clusters within 1 kpc of the Sun. This is the first systematic survey of these regions to date. The clusters range in size from several stars to a few hundred stars. Thirty fields ranging in size from 8 ′ ×8 ′ to 30 ′ × 60 ′ were mapped with 47 ′′ resolution simultaneously in the two J=1-0 lines at the Five College Radio Astronomy Observatory. Seventeen sources were mapped over fields ranging in size from 3 ′ × 3 ′ to 13 ′ × 13 ′ in the J=2-1 line with 35 ′′ resolution at the Submillimeter Telescope Observatory. We compare the cloud properties derived from each of the three tracers in order to better understand systematic uncertainties in determining masses and linewidths. Cloud masses are determined independently using the 13 CO and C 18 O transitions; these masses range from 30 to 4000 M ⊙ . Finally, we present a simple morphological classification scheme which may serve as a rough indicator of cloud evolution.

Outflows from young stellar objects (YSOs) have been identified as a possible source of turbulence in molecular clouds. To investigate the relationship between outflows, cloud dynamics, and turbulence, we compare the kinematics of the molecular gas associated with NGC 1333, traced in 13 CO (1-0), with the distribution of YSOs within. We find a velocity dispersion of $1-1.6 km s À1 in 13 CO that does not significantly vary across the cloud and is uncorrelated with the number of nearby young stellar outflows identified from optical and submillimeter observations. However, from velocity channel maps we identify about 20 depressions in the 13 CO intensity of scales k0.1-0.2 pc and velocity widths 1-3 km s À1 . The depressions exhibit limb-brightened rims in both individual velocity channel maps and position-velocity diagrams, suggesting that they are slowly expanding cavities. We interpret these depressions to be remnants of past YSO outflow activity: if these cavities are presently empty, they would fill in on timescales of $10 6 yr. This can exceed the lifetime of a YSO outflow phase or the transit time of the central star through the cavity, explaining the absence of any clear correlation between the cavities and YSO outflows. We find that the momentum and energy deposition associated with the expansion of the cavities is sufficient to power the turbulence in the cloud. In this way we conclude that the cavities are an important intermediate step between the conversion of YSO outflow energy and momentum into cloud turbulent motions.

We have surveyed a ~0.9-square-degree area of the W3 giant molecular cloud and star-forming region in the 850-micron continuum, using the SCUBA bolometer array on the James Clerk Maxwell Telescope. A complete sample of 316 dense clumps was detected with a mass range from around 13 to 2500 Msun. Part of the W3 GMC is subject to an interaction with the HII region and fast stellar winds generated by the nearby W4 OB association. We find that the fraction of total gas mass in dense, 850-micron traced structures is significantly altered by this interaction, being around 5% to 13% in the undisturbed cloud but ~25 - 37% in the feedback-affected region. The mass distribution in the detected clump sample depends somewhat on assumptions of dust temperature and is not a simple, single power law but contains significant structure at intermediate masses. This structure is likely to be due to crowding of sources near or below the spatial resolution of the observations. There is little evidence of any difference between the index of the high-mass end of the clump mass function in the compressed region and in the unaffected cloud. The consequences of these results are discussed in terms of current models of triggered star formation.Comment: 13 pages, 8 figures, 1 table (full source table available on request). Accepted for publication in Monthly Notices of the Royal Astronomical Society (Main Journal

Abstract. Spitzer Space Telescope observations of a point-like source, L1014-IRS, close to the dust peak of the low-mass dense core L1014, have raised questions about its starless nature. These show the presence of an object with colors expected for an embedded protostar with the implication that L1014-IRS would be the lowest luminosity isolated protostar known, and an ideal target with which to test star formation theories at the low mass end. In order to study its molecular content and to search for the presence of a molecular outflow, we mapped L1014 in at least one transition of 12 No classical signatures of molecular outflow are found in the 12 CO and 13 CO FCRAO observations. In particular, no high velocity wings are found, and no well-defined blue-red lobes of 12 CO emission are seen in the channel maps. Sensitive, higher resolution observations will clarify the presence of a molecular outflow on a smaller scale than that probed by our observations.

Abstract. We have made12 CO 2-1 and 1-0 maps of eleven molecular outflows associated with intermediate to high-mass young stellar objects (YSOs) in order to establish whether the correlations between outflow parameters and source bolometric luminosity hold in the high-mass regime. It is important to consider the effects of Malmquisttype biases when looking at high-mass YSOs, as they are generally much more distant than their low mass counterparts. We therefore chose only objects located at ∼2 kpc. We find that the relations show much more scatter than is seen in similar studies of low-mass YSOs. We also find that the mass-spectrum is significantly steeper in high-mass outflows, indicating a larger mass-fraction at lower velocities, a low collimation factor (∼1-2) and no Hubble-like relationship.