Related papers: Triggered star formation surrounding Wolf-Rayet st…
The current generation of millimeter interferometers have revealed a population of compact (r <~ 0.1 pc), massive (M ~ 100 Msun) gas cores that are the likely progenitors of massive stars. I review models for the evolution of these objects…
We present several molecular line emission arcsec and subarcsec observations obtained with the Submillimeter Array (SMA) in the direction of the massive protostar IRAS 18162-2048, the exciting source of HH 80-81. The data clearly indicates…
We present the detection and characterization of a peculiar low-mass protostar (IRAS 22129+7000) located ~0.4 pc from Ced 201 Photodissociation Region (PDR) and ~0.2 pc from the HH450 jet. The cold circumstellar envelope surrounding the…
We study the molecular and the ionized gas in a possible precursor of an UC HII region to contribute to the understanding of how high-mass stars build-up their masses once they have reached the zero-age main secuence. We carried out…
We present a multi-wavelength study of the IR bubble G24.136+00.436. The J=1-0 observations of $^{12}$CO, $^{13}$CO and C$^{18}$O were carried out with the Purple Mountain Observatory 13.7 m telescope. Molecular gas with a velocity of 94.8…
We studied the environment of the dust bubble N10 in molecular emission. Infrared bubbles, first detected by the GLIMPSE survey at 8.0 $\mu$m, are ideal regions to investigate the effect of the expansion of the HII region on its…
Using new continuum and molecular line data from the ALMA Three-millimeter Observations of Massive Star-forming Regions (ATOMS) survey and archival VLA, 4.86 GHz data, we present direct observational evidence of hierarchical triggering…
A supersonic cloud-cloud collision produces a shock-compressed layer which leads to formation of high-mass stars via gravitational instability. We carried out a detailed analysis of the layer by using the numerical simulations of…
To unravel the star formation process, we present a multi-scale and multi-wavelength study of the filamentary infrared dark cloud (IRDC) G333.73+0.37, which hosts previously known two HII regions located at its center. Each HII region is…
We use 2MASS and MSX infrared observations, along with new molecular line (CO) observations, to examine the distribution of young stellar objects (YSOs) in the molecular cloud surrounding the halo HII region KR 140 in order to determine if…
We present images and initial results from our extensive Spitzer Space Telescope imaging survey of the W5 H II region with the Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS). We detect dense clusters of…
The physical structure of hot molecular cores, where forming massive stars have heated up dense dust and gas, but have not yet ionized the molecules, poses a prominent challenge in the research of high-mass star formation and…
We present ultraviolet, optical, near-infrared, Spitzer mid-infrared, and radio images of 14 radio-selected objects in M 33. These objects are thought to represent the youngest phase of star cluster formation. We have detected the majority…
High-resolution observations in the near infrared show star clusters around the active galactic nucleus (AGN) of the Seyfert 1 NGC2110, along with a 90 x 35 pc bar of shocked gas material around its nucleus. These are seen for the first…
With the High Resolution Spectrograph aboard the Hubble Space Telescope we obtained high signal-to-noise (S/N > 200 - 600 per 17 km/s resolution element) spectra of narrow absorption lines toward the Wolf-Rayet star HD 50896. The ring…
We present a unified model for molecular core formation and evolution, based on numerical simulations of converging, supersonic flows. Our model applies to star formation in GMCs dominated by large-scale turbulence, and contains four main…
We model the late evolution and mass loss history of rapidly rotating Wolf-Rayet stars in the mass range $5\,\rm{M}_{\odot}\dots 100\,\rm{M}_{\odot}$. We find that quasi-chemically homogeneously evolving single stars computed with enhanced…
Super-sonic turbulence fragments molecular clouds (MC) into a very complex density field with density contrasts of several orders of magnitude. A fraction of the gas is locked into dense and gravitationally bound cores, which collapse as…
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…
Stars generally form faster than the ambipolar diffusion time, suggesting that several processes short circuit the delay and promote a rapid collapse. These processes are considered here, including turbulence compression in the outer parts…