相关论文: The cometary HII regions of DR 21: Bow shocks or c…

The DR 21 massive star forming region contains two cometary HII regions, aligned nearly perpendicular to each other on the sky. This offers a unique opportunity to discriminate among models of cometary HII regions. We present hydrogen…

We have mapped the velocity structure of the cometary compact HII region G29.96-0.02 using long-slit echelle spectra of the HI Br gamma line. This technique detects line emission over a much wider area at the necessary spatial resolution…

We present numerical radiation-hydrodynamic simulations of cometary HII regions for a number of champagne flow and bowshock models. For the champagne flow models we study smooth density distributions with both steep and shallow gradients.…

We have developed a full numerical method to study the gas dynamics of cometary ultra-compact (UC) H II regions, and associated photodissociation regions (PDRs). The bow-shock and champagne-flow models with a $40.9/21.9 M_\odot$ star are…

We present a new observation of the compact HII region, G29.96-0.02, that allows us to compare the velocity structure in the ionised gas and surrounding molecular gas directly. This allows us to remove most of the remaining ambiguity about…

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 probe the structure and kinematics of two neighbouring H II regions identified as cometary and bipolar, using radio recombination lines (RRL). The H172{\alpha} RRLs from these H II regions: G351.6-1.15 and G351.6-1.25, are mapped using…

High spectral and spatial resolution, mid-infrared fine structure line observations toward two ultracompact HII (UCHII) regions (G29.96 -0.02 and Mon R2) allow us to study the structure and kinematics of cometary UCHII regions. In our…

HII regions are the ionized spheres surrounding high-mass stars. They are ideal targets for tracing Galactic structure because they are predominantly found in spiral arms and have high luminosities at infrared and radio wavelengths. In the…

We present high angular and spectral resolution HI 21~cm line observations toward the cometary-shaped compact HII region G213.880-11.837 in the GGD~14 complex.The kinematics and morphology of the photodissociated region, traced by the HI…

We investigate the kinematic properties of Galactic HII regions using radio recombination line (RRL) emission detected by the Australia Telescope Compact Array (ATCA) at 4-10 GHz and the Jansky Very Large Array (VLA) at 8-10 GHz. Our HII…

The HH 1/2 system has been observed with the two spectrometers on board the Infrared Space Observatory. Diffuse [CII] 158um emission indicate the presence of a Photo-Dissociation Region (PDR) which is only in part due to the external Far-UV…

We report the results obtained from a multi-wavelength study of the HII region, G18.148$-$0.283, using the upgraded Giant Metre-wave Radio Telescope (uGMRT) at 1350 MHz along with other archival data. In addition to the radio continuum…

We observed radio recombination lines (RRLs) toward the W51 molecular cloud complex, one of the most active star forming regions in our Galaxy. The UV radiation from young massive stars ionizes gas surrounding them to produce HII regions.…

We have modelled the evolution of cometary HII regions produced by zero-age main-sequence stars of O and B spectral types, which are driving strong winds and are born off-centre from spherically symmetric cores with power-law ($\alpha = 2$)…

We have observed seven ultracompact HII regions in hydrogen recombination lines in the millimeter band. Toward four of these regions, there is a high velocity (full width to half maximum 60-80 km/s) component in the line profiles. The high…

We report multifrequency radio continuum and hydrogen radio recombination line observations of HII regions near l=24.8d b=0.1d using the Giant Metrewave Radio Telescope (GMRT) at 1.28 GHz (n=172), 0.61 GHz (n=220) and the Very Large Array…

The molecular gas in the DR21 massive star formation region is known to be affected by the strong UV field from the central star cluster and by a fast outflow creating a bright shock. The relative contribution of both heating mechanisms is…

HII regions made of gas ionized by radiations from young massive stars, are widely distributed in the Milky Way. They are tracers for star formation, and their distributions are correlated with the Galactic spiral structure. Radio…

Expansion of wind-blown bubbles or HII regions lead to formation of shocks in the interstellar medium, which compress surrounding gas into dense layers. We made spatially and velocity-resolved observations of the RCW~120 PDR and nearby…