Related papers: The "True" Column Density Distribution in Star-For…

We report the results of an HCO+ (3-2) and N2D+ (3-2) molecular line survey performed toward 91 dense cores in the Perseus molecular cloud using the James Clerk Maxwell Telescope, to identify the fraction of starless and protostellar cores…

We present an analysis of ~3.5 square degrees of submillimetre continuum and extinction data of the Perseus molecular cloud. We identify 58 clumps in the submillimetre map and we identify 39 structures (`cores') and 11 associations of…

We present a method of mapping dust column density in dark clouds by using near-infrared scattered light. Our observations of the Lupus 3 dark cloud indicate that there is a well defined relation between (1) the H-Ks color of an individual…

We investigate 35 pre-stellar cores and 36 proto-stellar cores in the Perseus molecular cloud. We find a very tight correlation between the physical parameters describing the N2H+ and NH3 gas. Both the velocity centroids and the line widths…

We generalize the technique of Lada et al. (1994) to map dust column density through a molecular cloud (NICE) to an optimized multi-band technique (NICER) that can be applied to any multi-band survey of molecular clouds. We present a first…

We present a new, approximate method of calculating the column density of ammonia in mapping observations of the 23 GHz inversion lines. The temperature regime typically found in star forming regions allows for the assumption of a slowly…

We report high resolution observations of the $^{12}$CO$(1\rightarrow0)$ and $^{13}$CO$(1\rightarrow0)$ molecular lines in the Carina Nebula and the Gum 31 region obtained with the 22-m Mopra telescope as part of the The Mopra Southern…

We use the COMPLETE data to derive new calibrations of the X-factor and the 13CO abundance within Perseus. We divide Perseus into six sub-regions. The standard X factor, X=N(H2)/W(12CO), is derived both for the whole Perseus Complex and for…

Emission from carbon monoxide (CO) is ubiquitously used as a tracer of dense star forming molecular clouds. There is, however, growing evidence that a significant fraction of CO emission originates from diffuse molecular gas. Quantifying…

Context. he study of prestellar cores is essential to understanding the initial stages of star formation. With $Herschel$ more cold clumps have been detected than ever before. For this study we have selected 21 cold clumps from 20…

Column density (N) PDFs serve as a powerful tool to characterize the physical processes that influence the structure of molecular clouds. Star-forming clouds can best be characterized by lognormal PDFs for the lower N range and a power-law…

The factor relating CO emission to molecular hydrogen column density, XCO, is still subject to uncertainty, in particular at low metallicity. Here, to quantify XCO at two different spatial resolutions, we exploit a dust-based method…

Context: In the last years, there have been many studies on the omnipresence and structures of filaments in star-forming regions, as well as their role in the process of star formation. Those filaments are normally identified as elongated…

We investigate the impact of high optical depth on the HI saturation observed in the Perseus molecular cloud by using Arecibo HI emission and absorption measurements toward 26 radio continuum sources. The spin temperature and optical depth…

Far-infrared continuum data from the {\it COBE}/{\it DIRBE} instrument were combined with Nagoya 4-m $\cOone$ spectral line data to infer the multiparsec-scale physical conditions in the Orion$ $A and B molecular clouds, using…

We present a complete survey of current star formation in the Perseus molecular cloud, made at 850 and 450 micron with SCUBA at the JCMT. Covering 3 deg^2, this submillimetre continuum survey for protostellar activity is second in size only…

Protostellar multiplicity is a common outcome of the star formation process. To fully understand the formation and evolution of these systems, the physical parameters of the molecular gas together with the dust must be systematically…

We present a survey of the Perseus molecular cloud in the J $=$ 1$\rightarrow$0 transition of HCN, a widely used tracer of dense molecular gas. The survey was conducted with the CfA 1.2 m telescope, which at 89 GHz has a beam width of 11'…

We aim to compare variations in the full-UV dust extinction curve (912-3000 Angstrom), with the HI/H$_2$/total H content along diffuse Milky Way sightlines, to investigate possible connections between ISM conditions and dust properties. We…

We present a method to estimate the total gas column density, dust-to-gas and dust-to-metal ratios of distant galaxies from rest-frame optical spectra. The technique exploits the sensitivity of certain optical lines to changes in depletion…