Related papers: NH3 Observations of the Infrared Dark Cloud G28.34…
The dense molecular clump P1 in the infrared dark cloud (IRDC) complex G28.34+0.06 harbors a massive protostellar cluster at its extreme youth. Our previous Submillimeter Array (SMA) observations revealed several jet-like CO outflows…
We present Very Large Array observations of ammonia (NH3) (1,1), (2,2), and CCS (2_1-1_0) emission toward the Infrared Dark Cloud (IRDC) G19.30+0.07 at ~22GHz. The NH3 emission closely follows the 8 micron extinction. The NH3 (1,1) and…
We present Submillimeter Array (SMA) \lambda = 0.88mm observations of an infrared dark cloud (IRDC) G28.34+0.06. Located in the quiescent southern part of the G28.34 cloud, the region of interest is a massive ($>10^3$\,\msun) molecular…
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…
We present the results of combined NH3(1,1) and (2,2) line emission observed with the Very Large Array and the Effelsberg 100m telescope of the Infrared Dark Cloud G14.225-0.506. The NH3 emission reveals a network of filaments constituting…
At a distance of 2.4kpc, W33 is an outstanding massive and luminous 10pc sized star forming complex containing quiescent infrared dark clouds as well as highly active infrared bright cloud cores heated by young massive stars. We report…
We have observed a cluster forming clump (MM3) associated with the infrared dark cloud G34.43+00.24 in the 1.3 mm continuum and the CH3OH, CS, 13CS, SiO, CH3CH2CN, and HCOOCH3 lines with the Atacama Large Millimeter/submillimeter Array and…
We have observed the J=3-2 transition of N2H+ and N2D+ to investigate the trend of deuterium fractionation with evolutionary stage in three selected regions in the Infrared Dark Cloud (IRDC) G28.34+0.06 with the Submillimeter Telescope…
We present a submm study of the massive hot core G327.3-0.6 that constrains its physical parameters and environment. The APEX telescope was used to image CO and N2H+ emission, to observe lines from other molecules toward a hot and a cold…
We present results of a multi-line study of the filamentary infrared dark cloud G351.78-0.54 in the 1.3 and 0.8 mm wavelength bands. The lines of the three isotopologues of carbon monoxide CO, N$_2$H$^+$, CH$_3$CCH and HNCO were observed.…
We present wide area radio (12 mm) Mopra Telescope observations of the complex and rich massive star forming region G305. Our goals are to determine the reservoir for star formation within G305 using NH3 to trace the dense molecular…
We present high-angular resolution sub-millimeter continuum images and molecular line spectra obtained with the SMA toward two massive cores that lie within Infrared Dark Clouds; one actively star-forming (G034.43+00.24 MM1) and the other…
We present results of an extensive mapping survey of N2H+(1-0) in about 60 low mass cloud cores already mapped in the NH3(1,1) inversion transition line. The survey has been carried out at the FCRAO antenna with an angular resolution about…
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…
Infrared-dark high-mass clumps are among the most promising objects to study the initial conditions of the formation process of high-mass stars and rich stellar clusters. In this work, we have observed the (3-2) rotational transition of…
The {\it Planck} Galactic Cold Clumps (PGCCs) are the possible representations of the initial conditions and the very early stages of star formation. With an objective to understand better the star and star cluster formation, we probe the…
Aims: The G28.37+0.07 star-forming region is a prototypical infrared dark cloud (IRDC) located at the interface of a converging gas flow. This study characterizes the properties of this dynamic gas flow. Methods: Combining data from the…
We have surveyed the N2H+ J=1-0, HC3N J=5-4, CCS J_N=4_3-3_2, NH3 (J, K) = (1, 1), (2, 2), (3, 3), and CH3OH J=7-6 lines toward the 55 massive clumps associated with infrared dark clouds by using the Nobeyama Radio Observatory 45 m…
G79.29+0.46 is a nebula created by a Luminous Blue Variable (LBV) star candidate characterized by two almost circular concentric shells. In order to investigate whether the shells are interacting with the infrared dark cloud (IRDC)…
Infrared-dark clouds (IRDCs) are believed to be the birthplaces of rich clusters and thus contain the earliest phases of high-mass star formation. We use the Green Bank Telescope (GBT) and Very Large Array (VLA) maps of ammonia (NH3) in six…