Infall motions in massive star-forming regions: results from years 1 and 2 of the MALT90 survey

  title={Infall motions in massive star-forming regions: results from years 1 and 2 of the MALT90 survey},
  author={Yuxin He and Jianjun Zhou and Jarken. Esimbek and Wei-guang Ji and Gang Wu and Xindi Tang and Ye Yuan and Da-lei Li and Willem A. Baan},
  journal={Monthly Notices of the Royal Astronomical Society},
Massive star-forming regions with observed infall motions are good sites for studying the birth of massive stars. In this paper, 405 compact sources have been extracted from the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) compact sources that also have been observed in the Millimetre Astronomy Legacy Team 90-GHz (MALT90) survey during years 1 and 2. These observations are complemented with Spitzer GLIMPSE/MIPSGAL mid-IR survey data to help classify the elected star-forming clumps… 
Properties of massive star-forming clumps with infall motions
In this work, we aim to characterise high-mass clumps with infall motions. We selected 327 clumps from the Millimetre Astronomy Legacy Team 90-GHz (MALT90) survey, and identified 100 infall
In search of infall motion in molecular clumps II: HCO+ (1–0) and HCN (1–0) observations toward a sub-sample of infall candidates
Gravitational accretion accumulates the original mass, and this process is crucial for us to understand the initial phases of star formation. Using the specific infall profiles in optically thick and
The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). IV. Star Formation Signatures in G023.477
With a mass of ∼1000 M ⊙ and a surface density of ∼0.5 g cm−2, G023.477+0.114, also known as IRDC 18310-4, is an infrared dark cloud (IRDC) that has the potential to form high-mass stars and has been
Probing the Massive Star-forming Environment: A Multiwavelength Investigation of the Filamentary IRDC G333.73+0.37
We present a multiwavelength study of the filamentary infrared dark cloud (IRDC) G333.73+0.37. The region contains two distinct mid-infrared sources S1 and S2 connected by dark lanes of gas and dust.
We present dust column densities and dust temperatures for ∼3000 young, high-mass molecular clumps from the Millimeter Astronomy Legacy Team 90 GHz survey, derived from adjusting single-temperature
In Search of Infall Motion in Molecular Clumps. III. HCO+ (1-0) and H13CO+ (1-0) Mapping Observations toward Confirmed Infall Sources
The study of infall motion helps us to understand the initial stages of star formation. In this paper, we use the IRAM 30 m telescope to make mapping observations of 24 infall sources confirmed in
Searching for Inflow toward Massive Starless Clump Candidates Identified in the Bolocam Galactic Plane Survey
Recent Galactic plane surveys of dust continuum emission at long wavelengths have identified a population of dense, massive clumps with no evidence for ongoing star formation. These massive starless
MALT90 molecular content on high-mass IR-dark clumps
Context. High mass stars form in groups or clusters in dense molecular clumps with sizes of 1 pc and masses of 200 M⊙. Infrared-dark clumps and the individual cores within them with sizes < 0.1 pc
The Chemical Structure of Young High-mass Star-forming Clumps. II. Parsec-scale CO Depletion and Deuterium Fraction of HCO+
The physical and chemical properties of cold and dense molecular clouds are key to understanding how stars form. Using the IRAM 30 m and NRO 45 m telescopes, we carried out a Multiwavelength
Herschel-HOBYS study of the earliest phases of high-mass star formation in NGC 6357
Aims. To constrain models of high-mass star formation it is important to identify the massive dense cores (MDCs) that are able to form high-mass star(s). This is one of the purposes of the


The chemical changes of high-mass star-forming regions provide a potential method for classifying their evolutionary stages and, ultimately, ages. In this study, we search for correlations between
Signatures of Inflow Motion in Cores of Massive Star Formation: Potential Collapse Candidates
Using the IRAM 30 m telescope, a mapping survey in optically thick and thin lines was performed toward 46 high-mass-star-forming regions. The sample includes UC H II precursors and UC H II regions.
A comparative study of high-mass cluster forming clumps
Aims. We have searched for star formation activity (mainly infall and outflow signatures) in a sample of high-mass molecular clumps (M > 100 M� )i n different evolutionary stages and with a wide
Outflow and Infall in a Sample of Massive Star-forming Regions
We present single-pointing observations of SiO, HCO+, and H13CO+ from the James Clerk Maxwell Telescope toward 23 massive star-forming regions previously known to contain molecular outflows and
SIMBA survey of southern high-mass star forming regions. I. Physical parameters of the 1.2-mm/IRAS sources
We report the results of a 1.2 mm continuum emission survey toward 146 IRAS sources thought to harbour high- mass star forming regions. The sources have FIR colors typical of UCHII regions and were
Looking for outflow and infall signatures in high-mass star-forming regions
Context. Many physical parameters change with time in star-forming regions. Here we attempt to correlate changes in the infall and outflow motions in high-mass star-forming regions with evolutionary
ATLASGAL – environments of 6.7 GHz methanol masers
Using the 870 μm APEX Telescope large area survey of the Galaxy, we have identified 577 submillimetre continuum sources with masers from the methanol multibeam survey in the region 280° 20 M.
The RMS survey - 6 cm continuum VLA observations towards candidate massive YSOs in the northern hemisphere
Context. The Red MSX Source (RMS) survey is an ongoing multi-wavelength observational programme designed to return a large, well-selected sample of massive young stellar objects (MYSOs). We have
A Search for Infall Motions toward Nearby Young Stellar Objects
We report observations of 47 candidate protostars in two optically thick lines [H2CO (212-111) and CS (2-1)] and one optically thin line [N2H+ (1-0)] using the IRAM 30 m, SEST 15 m, and Haystack 37 m
A 5-GHz VLA Survey of the Galactic Plane (Becker+ 1994)
We have used the Very Large Array (VLA) to survey the inner Galaxy (absolute value of b less than 0.4 deg, l = 350-40 deg) at 5 GHz to a limiting sensitivity of between 2.5 and 10 mJy. The survey has