Related papers: Gas infall via accretion disk feeding Cepheus A HW…
Young low-mass stars are characterized by ejection of collimated outflows and by circumstellar disks which they interact with through accretion of mass. The accretion builds up the star to its final mass and is also believed to power the…
The 6.7 GHz methanol maser is exclusively associated with high-mass star formation. However, it remains unclear what structures harbour the methanol masers. Cepheus A is one of the closest regions of massive star formation, making it an…
The hypothesis that massive stars form by accretion can be investigated by simple analytical calculations that describe the effect that the formation of a massive star has on its own accretion flow. Within a simple accretion model that…
We present a study of outflow, infall, and rotation in a ~10^5 Lsun (solar luminosity) star-forming region, IRAS 18360-0537, with Submillimeter Array (SMA) and IRAM 30m observations. The 1.3 mm continuum map shows a 0.5 pc dust ridge, of…
We present new far-ultraviolet observations of the young M8 brown dwarf 2MASS J12073346-3932539, which is surrounded by an accretion disk. The data were obtained using the Hubble Space Telescope-Cosmic Origins Spectrograph. Moderate…
We report the results of a search for pure rotational molecular hydrogen emission from the circumstellar environments of young stellar objects with disks using the Texas Echelon Cross Echelle Spectrograph (TEXES) on the NASA Infrared…
We propose a scenario in which massive stars form in a self-gravitating gaseous disc around a supermassive black hole. We find that once the surface density of the disc exceeds a critical value, the disc fragments into dense clumps. The…
We analyse the chemical properties of a set of solar vicinity stars, and show that the small dispersion in abundances of \alpha-elements at all ages provides evidence that the SFH has been uniform throughout the thick disk. In the context…
We use a suite a cooling halo simulations to study a new mechanism for rapid accretion of hot halo gas onto star-forming galaxies. Correlated supernovae events create converging 'superbubbles' in the halo gas. Where these collide, the…
We present high spatial resolution ($52$ au) observations of the high-mass young stellar object (HMYSO) G345.4938+01.4677 made using the Atacama Large Millimeter/sub-millimeter Array (ALMA). This O-type HMYSO is located at 2.38 kpc and it…
We describe the first three-dimensional simulation of the gravitational collapse of a massive, rotating molecular cloud that includes heating by both non-ionizing and ionizing radiation. We find that as the first protostars gain sufficient…
Solar-mass stars form via circumstellar disk accretion (disk-mediated accretion). Recent findings indicate that this process is likely episodic in the form of accretion bursts, possibly caused by disk fragmentation. Although it cannot be…
Galaxy formation depends on a complex interplay between gravitational collapse, gas accretion, merging, and feedback processes. Yet, after many decades of investigation, these concepts are poorly understood. This paper presents the argument…
Gas accretion is a key process in star formation. However, the gas infall detections in high-mass star forming regions with high-spatial resolution observations are rare. Here we report the detection of gas infall towards a cometary…
Astronomers have established that for a few million years newborn stars possess disks of orbiting gas and dust. Such disks, which are likely sites of planet formation, appear to disappear once these stars reach ages of 5-10 times 10^6 yr;…
The formation scenario of extended counter-rotating stellar disks in galaxies is still debated. In this paper, we study the S0 galaxy IC 719 known to host two large-scale counter-rotating stellar disks in order to investigate their…
Millimeter sized dust grains experience radial velocities exceeding the gas velocities by orders of magnitude. The viscous evolution of the accretion disk adds disk material onto the central star's convective envelope, influencing its…
We present ISO-SWS observations of H2 pure-rotational line emission from the disks around low and intermediate mass pre-main-sequence stars as well as from young stars thought to be surrounded by debris disks. We detect `warm' (T ~ 100-200…
(Reduced)Using the NewHorizon simulation, we have studied ten gas-versus-star counter-rotating galaxies in field environments with a stellar mass of M*~[1-5]x10^10 Msun. For all of them, the retrograde accretion of gas either from gas…
Massive stars can form within or be captured by AGN disks, influencing both the thermal structure and metallicity of the disk environment. In a previous work, we investigated isotropic accretion onto massive stars from a gas-rich,…