Related papers: Hot high-mass accretion disk candidates
Aims: We resolve the small-scale structure around the high-mass hot core region G351.77-0.54 to investigate its disk and fragmentation properties. Methods: Using ALMA at 690GHz with baselines exceeding 1.5km, we study the dense gas, dust…
Young massive stars warm up the large amount of gas and dust which condenses in their vicinity, exciting a forest of lines from different molecular species. Their line brightness is a diagnostic tool of the gas physical conditions locally,…
A classical paradox in high-mass star formation is that powerful radiation pressure can halt accretion, preventing further growth of a central star. Disk accretion has been proposed to solve this problem, but the disks and the accretion…
Increasing evidence suggests that, similar to their low-mass counterparts, high-mass stars form through a disk-mediated accretion process. At the same time, formation of high-mass stars still necessitates high accretion rates, and hence,…
Based on spectroscopic signatures, about one-third of known H$_2$O maser sources in active galactic nuclei (AGN) are believed to arise in highly inclined accretion disks around central engines. These "disk maser candidates" are of interest…
We have observed the ultracompact HII region G10.6-0.4 with the VLA in 23 GHz continuum and the NH3(3,3) inversion line. By analyzing the optical depth of the line as well as the kinematics, we have detected a flattened, rotating, molecular…
This is the first paper of our series of high resolution (1") studies of the massive star forming region G10.6--0.4. We present the emission line observations of the hot core type tracers (O$^{13}$CS, OCS, SO$_{2}$) with $\sim$0$"$.5…
Using the OVRO, Nobeyama, and IRAM mm-arrays, we searched for ``disk''-outflow systems in three high-mass (proto)star forming regions: G16.59-0.05, G23.01-0.41, and G28.87+0.07. These were selected from a sample of NH3 cores associated with…
The formation process of massive stars is not well understood, and advancement in our understanding benefits from high resolution observations and modelling of the gas and dust surrounding individual high-mass (proto)stars. Here we report…
Circumstellar disks are an essential ingredient of the formation of low-mass stars. It is unclear, however, whether the accretion-disk paradigm can also account for the formation of stars more massive than about 10 solar masses, in which…
We present results of continuum and spectral line observations with ALMA and 22 GHz water (H$_2$O) maser observations using KaVA and VERA toward a high-mass star-forming region, G25.82-0.17. Multiple 1.3 mm continuum sources are revealed,…
We report on the detection of four rotating massive disks in two regions of high-mass star formation. The disks are perpendicular to known bipolar outflows and turn out to be unstable but long lived. We infer that accretion onto the…
Submillimeter Array 1.3mm line and continuum observations toward the young massive star-forming region IRAS18182-1433 are presented. The data are complemented with short-spacing CO(2-1) observations and SiO(1-0) data from the VLA. Multiple…
The massive young stellar object S255IR NIRS3 embedded in the star forming core SMA1 has been recently observed with a luminosity burst, which is conjectured as a disc-mediated variable accretion event. In this context, it is imperative to…
The fragmentation mode of high-mass molecular clumps and the accretion processes that form the most massive stars ($M\gtrsim 8M_\odot$) are still not well understood. To this end, we have undertaken a large observational program (CORE)…
This paper is the third in a series of ammonia multilevel imaging studies in well-known high-mass star forming regions. Using the JVLA, we have mapped the hot and dense molecular gas in W51 Main, with about 0.2 arcsec angular resolution, in…
In the disk-mediated accretion scenario for the formation of the most massive stars, gravitational instabilities in the disk can force it to fragment. We investigate the effects of inclination and spatial resolution on observable kinematics…
It is well established that Solar-mass stars gain mass via disk accretion, until the mass reservoir of the disk is exhausted and dispersed, or condenses into planetesimals. Accretion disks are intimately coupled with mass ejection via polar…
We present high angular resolution interferometric observations of the 3 and 1.3mm continuum emission, and HCO+(1-0) and SiO(2-1)v=0 lines, obtained with the Owens Valley Radio Observatory millimeter-wave array, toward two hot cores (HCs)…
Of 104 AGN known to exhibit H$_2$O maser emission, X-ray data that enable estimation of column densities, or lower limits, are available for 42. Contributing to this, we report analysis of new and archival X-ray data for 8 galaxies and…