Related papers: Hydrodynamical models of cometary HII regions
We carried out 13CO J=1-0, CS, and C34S J=2-1 and J=3-2 line observations of molecular clouds associated with 16 ultracompact (UC) HII regions with extended envelopes. The molecular clouds are the ones that give birth to rich stellar…
We review the structural properties of giant extragalactic HII regions and HII galaxies based on two dimensional hydrodynamic calculations, and propose an evolutionary sequence that accounts for their observed detailed structure. The model…
At least 5 per cent of the massive stars are moving supersonically through the interstellar medium (ISM) and are expected to produce a stellar wind bow shock. We explore how the mass loss and space velocity of massive runaway stars affect…
High-quality K-band spectra of strongly reddened point sources, deeply embedded in (ultra-) compact HII regions, have revealed a population of 20 young massive stars showing no photospheric absorption lines, but sometimes strong Br-gamma…
The HII region luminosity function (LF) is an important tool for deriving the birthrates and mass distribution of OB associations, and is an excellent tracer of the newly formed massive stars and associations. To date, extensive work…
Far-UV (FUV), H-alpha, and HI observations of dwarf galaxy Holmberg II are used to trace the interaction between sites of massive star formation and the neutral and ionized components of the surrounding ISM. The data emphasize the…
Using the Owens Valley and Nobeyama Radio Observatory interferometers, we carried out an unbiased search for hot molecular cores and ultracompact UC HII regions toward the high-mass star forming region G19.61--0.23. In addition, we…
One of the fundamental factors regulating the evolution of galaxies is stellar feedback. However, we still do not have strong observational constraints on the relative importance of the different feedback mechanisms (e.g. radiation, ionised…
Using ACS-HST images to yield continuum subtracted photometric maps in H\alpha of the Sbc galaxy M51 and the dwarf irregular galaxy NGC 4449, we produced extensive (over 2000 regions for M51, over 200 regions for NGC4449) catalogues of…
We model the combined effects of photoionization and momentum--driven winds from O--stars on molecular clouds spanning a parameter space of initial conditions. The dynamical effects of the winds are very modest. However, in the lower--mass…
Context: High-mass star formation has been a very active field over the last decade, however, most studies targeted regions of luminosities between 10^4 and 10^5 L_sun. Methods: We selected the W31 star-forming complex with a total…
A number of giant cometary HII regions (GCH) sheathed inside molecular bow shocks (MBS) are found along spiral arms of the barred galaxy M83. The open cone structure is explained by a model of expanded HII front in a gaseous arm with steep…
This paper investigates the gravitational trapping of HII regions predicted by steady-state analysis using radiation hydrodynamical simulations. We present idealised spherically symmetric radiation hydrodynamical simulations of the early…
Resolution of nearby giant HII regions into their stellar and nebular constituents provides fundamental insights for interpreting more distant and powerful starburst activity. The following summarizes recent advances in our understanding of…
The ionized core in the Sgr B2 Main star-forming region was imaged using the Submillimeter Array archival data observed for the H26$\alpha$ line and continuum emission at 0.86 millimeter with an angular resolution 0.3\arcsec. Eight…
Context. Massive-star formation triggered by the expansion of HII regions. Aims. To understand if sequential star formation is taking place at the periphery of the HII region Sh2-219. Methods. We present 12CO(2-1) line observations of this…
We present the properties of 8 star-forming regions, or 'clumps,' in 3 galaxies at z~1.3 from the WiggleZ Dark Energy Survey, which are resolved with the OSIRIS integral field spectrograph. Within turbulent discs, \sigma~90 km/s, clumps are…
We examine the triggering process of molecular cloud formation around diffuse HII regions. We calculate the time evolution of the shell as well as of the HII region in a two-phase neutral medium, solving the UV and FUV radiative transfer,…
We simulate evolution of cometary H II regions based on several champagne flow models and bow shock models, and calculate the profiles of the [Ne II] fine-structure line at $12.81\mu m$, the $H30\alpha$ recombination line and the [Ne III]…
We suggest that Bipolar H{\sc ii} Regions may be the aftermath of collisions between clouds. Such a collision will produce a shock-compressed layer, and a star cluster can then condense out of the dense gas near the centre of the layer. If…