Related papers: SDC13 infrared dark clouds: Longitudinally collaps…
We performed a multiwavelength study toward infrared dark cloud (IRDC) G34.43+0.24. New maps of 13CO $J$=1-0 and C18}O J=1-0 were obtained from the Purple Mountain Observatory (PMO) 13.7 m radio telescope. At 8 um (Spitzer - IRAC), IRDC…
Context. Infrared dark clouds (IRDCs) are ubiquitous in the Milky Way, yet they play a crucial role in breeding newly-formed stars. Aims. With the aim of further understanding the dynamics, chemistry, and evolution of IRDCs, we carried out…
Infrared Dark Clouds appear to be the long sought population of cold and dense aggregations with the potential of harbouring the earliest stages of massive star formation. Up to now there has been no systematic study on the temperature…
Context. Low-mass star-forming cores differ from their surrounding molecular cloud in turbulence, shape, and density structure. Aims. We aim to understand how dense cores form out of the less dense cloud material by studying the connection…
We present new Plateau de Bure Interferometer observations of a region in the filamentary infrared-dark cloud (IRDC) G011.11-0.12 containing young, star-forming cores. In addition to the 3.2mm continuum emission from cold dust, we map this…
We present SOFIA-upGREAT observations of [CII] emission of Infrared Dark Cloud (IRDC) G035.39-00.33, designed to trace its atomic gas envelope and thus test models of the origins of such clouds. Several velocity components of [CII] emission…
Infrared Dark Clouds (IRDCs) are dense molecular clouds seen as extinction features against the bright mid-infrared Galactic background. Millimeter continuum maps toward 38 IRDCs reveal extended cold dust emission to be associated with each…
To study the fragmentation and gravitational collapse of dense cores in infrared dark clouds (IRDCs), we have obtained submillimeter continuum and spectral line data as well as multiple inversion transitions of NH3 and H2O maser data of…
Much of the dense gas in molecular clouds has a filamentary structure but the detailed structure and evolution of this gas is poorly known. We have observed 54 cores in infrared dark clouds (IRDCs) using N$_2$H$^+$ (1-0) and (3-2) to…
The aim of this study is to better understand the physical and chemical properties of the filamentary IRDC G304.74+01.32. In particular, we aim to investigate the kinematics and dynamical state of the cloud and clumps within it, and the…
Some theories of dense molecular cloud formation involve dynamical environments driven by converging atomic flows or collisions between preexisting molecular clouds. The determination of the dynamics and physical conditions of the gas in…
We present millimeter interferometric observations of the young stellar object SVS13 in NCG1333 in the N2H+(1-0) line and at 1.4 and 3mm dust continuum, using the IRAM Plateau de Bure interferometer. The results are complemented by infrared…
Infrared-dark clouds (IRDCs) are the precursors to massive stars and stellar clusters. G011.11-0.12 is a well-studied filamentary IRDC, though, to date, the absence of far-infrared data with sufficient spatial resolution has limited the…
High-mass stars have an enormous influence on the evolution of the interstellar medium in galaxies, so it is important that we understand how they form. We examine the central clumps within a sample of seven infrared-dark clouds (IRDCs)…
Stars are born from dense cores in molecular clouds. Observationally, it is crucial to capture the formation of cores in order to understand the necessary conditions and rate of the star formation process. The {\it Atacama Large Mm/sub-mm…
Interferometric observations of the W33A massive star-formation region, performed with the Submillimeter Array (SMA) and the Very Large Array (VLA) at resolutions from 5 arcsec (0.1 pc) to 0.5 arcsec (0.01 pc) are presented. Our three main…
Infrared Dark Clouds (IRDCs) are cold, high mass surface density and high density structures, likely to be representative of the initial conditions for massive star and star cluster formation. CO emission from IRDCs has the potential to be…
It is commonly assumed that cold and dense Infrared Dark Clouds (IRDCs) likely represent the birth sites massive stars. Therefore, this class of objects gets increasing attention. To enlarge the sample of well-characterised IRDCs in the…
The G14.225-0.506 infrared dark cloud (IRDC G14.2) displays a remarkable complex of parallel dense molecular filaments projected on the plane of the sky. Previous dust emission and molecular-line studies have speculated whether magnetic…
The relative importance of primordial molecular cloud fragmentation versus large-scale accretion still remains to be assessed in the context of massive core/star formation. Studying the kinematics of the dense gas surrounding massive-star…