Related papers: Outflow and dense gas emission from massive Infrar…
We have used data taken as part of the Herschel infrared Galactic Plane survey (Hi-GAL) to study 3171 infrared-dark cloud (IRDC) candidates that were identified in the mid-infrared (8 {\mu}m) by Spitzer (we refer to these as 'Spitzer-dark'…
Chemical composition of the massive cores forming high-mass stars can put some constrains on the time scale of the massive star formation: sulphur chemistry is of specific interest due to its rapid evolution in warm gas and because the…
We mapped the MSX dark cloud G084.81-01.09 in the NH3 (1,1) - (4,4) lines and in the J = 1-0 transitions of 12CO, 13CO, C18O and HCO+ in order to study the physical properties of infrared dark clouds, and to better understand the initial…
Water is a key molecule in the star formation process, but its spatial distribution in star-forming regions is not well known. We study the distribution of dust continuum and H2O and 13CO line emission in DR21, a luminous star-forming…
We characterize the physical properties of star-formation driven outflows in a sample of 29 local dwarf galaxies drawn from the Dwarf Galaxy Survey. We make use of Herschel/PACS archival data to search for atomic outflow signatures in the…
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…
The connection between high-mass stars and young stellar clusters has been well established by near-IR observations showing young massive stars in HII regions surrounded by clusters of lower mass stars. Mm-wave observations show that these…
We present a search for infrared dust emission associated with the Leo cloud, a large intergalactic cloud in the M96 group. Mid-infrared and far-infrared images were obtained with IRAC and MIPS on the Spitzer Space Telescope. Our analysis…
The evolutionary sequence for high-mass star formation starts with massive starless clumps that go on to form protostellar, young stellar objects and then compact HII regions. While there are many examples of the three later stages, the…
We present search results of 22 high latitude (b > 25 deg.) sightlines for OH 18-cm emission using the 305-m radio telescope at the Arecibo Observatory. These sightlines appear in neutral hydrogen emission at intermediate velocities (V_lsr…
The 500 central pc of the Galaxy (hereafter GC) exhibit a widespread gas component with a kinetic temperature of 100-200 K. The bulk of this gas is not associated to the well-known thermal radio continuum or far infrared sources like Sgr A…
We present observations of 1.2-mm dust continuum emission, made with the Swedish ESO Submillimeter Telescope, towards eighteen luminous IRAS point sources, all with colors typical of compact HII regions and associated with CS(2-1) emission,…
The densest infrared dark clouds (IRDCs) may represent the earliest observable stage of high-mass star formation. These clouds are very cold, hence they emit mainly at far-infrared and sub-mm wavelengths. For the first time, Herschel has…
We have searched for massive molecular outflows in a sample of high-mass star forming regions, and we have characterised both the outflow properties and those of their associated molecular clumps. With a sample composed largely of more…
Based on color-selected IRAS point sources, we have started to conduct a survey of 47 high-mass star-forming regions in the southern hemisphere in 870um dust continuum and molecular line emission in several frequency ranges between 290 GHz…
Dense cores in massive, parsec-scale molecular clumps are sites that harbor protocluster formation. We present results from observations towards a hub-filament structure of a massive Infrared Dark Cloud (IRDC) G14.225-0.506 using the…
We aim at characterizing the large-scale distribution of H2O in G327.3-0.6, a massive star-forming region made of individual objects in different evolutionary phases. We investigate variations of H2O abundance as function of evolution. We…
We observe 1.3~mm spectral lines at 2000~AU resolution toward four massive molecular clouds in the Central Molecular Zone of the Galaxy to investigate their star formation activities. We focus on several potential shock tracers that are…
The onset of massive star formation is not well understood because of observational and theoretical difficulties. To find the dense and cold clumps where massive star formation can take place, we compiled a sample of high infrared…
We present Very Large Array observations of NH3 (1,1) and (2,2) in a sample of six infrared-dark clouds (IRDCs) with distances from 2 to 5 kpc. We find that ammonia serves as an excellent tracer of dense gas in IRDCs, showing no evidence of…