相关论文: Three generations of stars: a possible case of tri…
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 investigate the star formation activity in the molecular complex associated with the Galactic HII region Sh2-90, using radio-continuum maps obtained at 1280 MHz and 610 MHz, Herschel Hi-GAL observations at 70 -- 500 microns, and deep…
As part of a systematic study that we are performing with the aim to increase the observational evidence of triggered star formation in the surroundings of HII regions, we analyze the ISM around the HII region G35.673-00.847, a poorly…
This work aims to the study of the Sh 2-307 HII region and related stellar population. Near-infrared imaging and spectroscopic observations in the direction of Sh 2-307 were performed using OSIRIS at SOAR Telescope. From J-, H- and K-band…
Mid-infrared (MIR) shells or bubbles around expanding H II regions have received much attention due to their ability to initiate a new generation of star formation. We present multi-wavelength observations around two bubbles associated with…
In this paper an extensive survey of the star forming complex Sh2-252 has been undertaken with an aim to explore its hidden young stellar population as well as to understand the structure and star formation history. This complex is composed…
Aims: We wish to establish whether sequential star formation is taking place at the periphery of the Galactic HII region Sh2-212. Methods: We present CO millimetre observations of this region obtained at the IRAM 30-m telescope to…
Based on a multiwavelength study, the interstellar medium and young stellar objects (YSOs) around the HII region Sh2-82 have been analyzed. Two molecular clumps were found from the archival data of the Galactic Ring Survey, and using the…
We present Heinrich Hertz Telescope CO observations of the shell structure near the active star-forming complex W51A to investigate the process of star formation triggered by the expansion of an HII region. The CO observations confirm that…
The Sh2-294 HII region ionized by a single B0V star features several infrared excess sources, a photodissociation region, and also a group of reddened stars at its border. The star formation scenario in the region seems to be quite complex.…
Stars are formed by gravitational collapse, spontaneously or, in some cases under the constructive influence of nearby massive stars, out of molecular cloud cores. Here we present an observational diagnosis of such triggered formation…
We investigated six H II regions with infrared, bright rimmed bubble or cometary morphology, in search of quantitative evidence for triggered star formation, both collect and collapse and radiatively driven implosion. We identified and…
To investigate the environment of HII region Sh2-163 and search for evidence of triggered star formation in this region, we performed a multi-wavelength study of this HII region. Most of our data were taken from large-scale surveys: 2MASS,…
HII regions are particularly interesting because they can generate dense layers of gas and dust, elongated columns or pillars of gas pointing towards the ionizing sources, and cometary globules of dense gas, where triggered star formation…
We present a picture of star formation around the HII region Sh2-235 (S235) based upon data on the spatial distribution of young stellar clusters and the distribution and kinematics of molecular gas around S235. We observed 13CO(1-0) and…
We are engaged in a multi-wavelength study of several Galactic HII regions that exhibit signposts of triggered star formation on their borders, and where the collect and collapse process could be at work. When addressing the question of…
Young massive stars or clusters are often observed at the peripheries of HII regions. What triggers star formation at such locations? Among the scenarios that have been proposed, the `collect and collapse' process is particularly attractive…
Sometimes the early star formation can be found in cold and dense molecular clouds, such as infrared dark cloud (IRDC). Considering star formation often occurs in clustered condition, HII regions may be triggering a new generation of star…
We investigated the distributions of classified young stellar object (YSO) in nine star-forming regions associated with Hii regions, namely Sh2-22, Sh2-19, Sh2-17, M16, M8, IC5070, Sh2-252, NGC2467 and M42, as a means of exploring the star…
Recent 1.2-mm continuum observations have shown the giant HII region NGC3576 to be embedded in the centre of an extended filamentary dust-cloud. The bulk of the filament away from the HII region contains a number of clumps seen only at…