相关论文: Magnetic fields and Star Formation around HII regi…
We study the structure of the medium surrounding sites of high-mass star formation to determine the interrelation between the HII regions and the environment from which they were formed. The density distribution of the surroundings is key…
We present the first detailed study of the large, ~30 pc diameter, inner-Galaxy HII region W 39. Radio recombination line observations combined with HI absorption spectra and Galactic rotation models show that the region lies at V(LSR) =…
Radio continuum observations allow to reveal the magnetic field structure in the disk and halo of nearby spiral galaxies, their magnetic field strength and vertical scale heights. The spiral galaxies studied so far show a similar magnetic…
Star formation is thought to be driven by two groups of mechanisms; spontaneous collapse and triggered collapse. Triggered star formation mechanisms further diverge into cloud-cloud collision (CCC), "collect and collapse" (C\&C) and shock…
We present results on the star-formation activity of an optically obscured region containing an embedded cluster (S255-IR) and molecular gas between two evolved HII regions S255 and S257. We have studied the complex using optical,…
Spitzer IRAC images (3.6, 4.5, 5.8 and 8.0$\mu$m) and photometry of the star forming region M8 are presented. IRAC photometry reveals ongoing star formation in the M8 complex, with 64 Class 0/I and 168 Class II sources identified in several…
[abridged] The role of magnetic fields in the process of star formation is a matter of continuous debate. Clear observational proof of the general influence of magnetic fields on the early phase of cloud collapse is still pending. First…
Magnetic fields are considered as a vital ingredient of contemporary star formation, and may have been important during the formation of the first stars in the presence of an efficient amplification mechanism. Initial seed fields are…
We analyze the statistical properties of the circumnuclear HII regions of a sample of 52 nearby galaxies ($v < 1000km/s) from archival HST/NICMOS H-band and Pa alpha (1.87micron) observations at unprecedented spatial resolutions of between…
We are studying the impact of HII regions on star formation in their associated molecular clouds. In this paper we present JCMT RxA molecular line observations of S175 and environs. This is the first within a sample of ten HII regions and…
We report on the detection of optically thick free-free radio sources in the galaxies M33, NGC 253, and NGC 6946 using data in the literature. We interpret these sources as being young, embedded star birth regions, which are likely to be…
Magnetic fields play an important role in the evolution of interstellar medium and star formation. As the only direct probe of interstellar field strength, credible Zeeman measurements remain sparse due to the lack of suitable Zeeman…
The regulation of galactic-scale star formation rates (SFRs) is a basic problem for theories of galaxy formation and evolution: which processes are responsible for making observed star formation rates so inefficient compared to maximal…
We present near-infrared integral-field spectroscopic observations targeting H$\alpha$ in eight sub-millimeter galaxies (SMGs) at $z$=1.3-2.5 using VLT/SINFONI, obtaining significant detections for six of them. The star formation rates…
Massive stars, multiple stellar systems and clusters are born from the gravitational collapse of massive dense gaseous clumps, and the way these systems form strongly depends on how the parent clump fragments into cores during collapse.…
In nearby star-forming clouds, amplification and dissipation of the magnetic field are known to play crucial roles in the star-formation process. The star-forming environment varies from place to place and era to era in galaxies. In the…
The interstellar medium (ISM) is permeated by magnetic fields that affect gas dynamics and star formation. These fields correlate with supernova (SN)-driven turbulence, but whether the scaling is universal across galaxy properties, ISM…
We report subarcsecond-resolution VLA imaging of four nearby spiral galaxies: IC 342, Maffei II, NGC 2903, and NGC 6946. In each galaxy, compact radio continuum sources are identified in the central ~ 15" x 15" region. These compact sources…
Observations show that star formation is an inefficient and slow process. This result can be attributed to the injection of energy and momentum by stars that prevents free-fall collapse of molecular clouds. The mechanism of this stellar…
We surveyed the (1,1), (2,2), and (3,3) lines of NH3 and the H2O maser toward the molecular cloud L935 in the extended HII region NGC 7000 with an angular resolution of 1.6' using the Kashima 34-m telescope. We found five clumps in the NH3…