Related papers: Gum 48d: an evolved HII region with ongoing star f…

We study star formation processes in the disc of the weakly barred grand design spiral galaxy M100 (NGC 4321) from a variety of images tracing recent massive star formation, old and young stars, dust, and neutral hydrogen. Differences…

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 perform a multiwavelength study toward the SNR G18.1-0.1 and nearby several HII regions (infrared dust bubbles N21 and N22, and the HII regions G018.149-00.283 and G18.197-00.181). Our goal is to provide observational evidence supporting…

Over a timescale of a few years, an observed change in the optically thick radio continuum flux can indicate whether an unresolved H II region around a newly formed massive star is changing in size. In this Letter we report on a study of…

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…

We study two dimensional Fabry-Perot interferometric observations of the nearby face-on late-type spiral galaxy, NGC 628, in order to analyse the ionized gas component of the interstellar medium. Covering the galaxy out to a radius larger…

(Abridged) Massive stars can determine the evolution of molecular clouds with their strong ultraviolet (UV) radiation fields. Moreover, UV radiation is relevant in setting the thermal gas pressure in star-forming clouds, whose influence can…

To understand the formation of stellar groups, one must first document carefully the birth pattern within real clusters and associations. In this study of Taurus-Auriga, we combine pre-main-sequence ages from our own evolutionary tracks…

We present new Spitzer Space Telescope observations of the region NGC 2467, and use these observations to determine how the environment of an HII region affects the process of star formation. Our observations comprise IRAC (3.6, 4.5, 5.8,…

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…

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…

We report on a study of the high-mass star formation in the the HII region W28A2 by investigating the molecular clouds extended over ~5-10 pc from the exciting stars using the 12CO and 13CO (J=1-0) and 12CO (J=2-1) data taken by the NANTEN2…

We report high angular resolution (3") Submillimeter Array (SMA) observations of the molecular cloud associated with the Ultra-Compact HII region G5.89-0.39. Imaged dust continuum emission at 870 micron reveals significant linear…

To probe the star formation (SF) process, we present a thorough multi-wavelength investigation of several H II regions located toward l = 24.8 deg, b = 0.1 deg. A system of at least five H II regions including the mid-infrared bubble N36…

We conduct a Galactic census of Giant HII regions, based on the all sky 6cm dataset of Kuchar & Clark, plus the kinematic distances obtained by Russeil. From an inspection of mid-IR Mid-course Space Experiment (MSX) and far-IR IRAS Sky…

The concordance model of cosmology and structure formation predicts the formation of isolated very massive stars at high redshifts in dark matter dominated halos of 10^5 to 10^6 Msun. These stars photo-ionize their host primordial molecular…

We present MUSE integral field data of two HII region complexes in the Large Magellanic Cloud (LMC), N44 and N180. Both regions consist of a main superbubble and a number of smaller, more compact HII regions that formed on the edge of the…

Chemical abundances in the Leo ring, the largest HI cloud in the local Universe, have recently been determined to be close or above solar, incompatible with a previously claimed primordial origin of the ring. The gas, pre-enriched in a…

Aims. We present molecular line observations of the southwestern part of the IC 348 young cluster, and we use them together with NIR and mm continuum data to determine the distribution of dense gas, search for molecular outflows, and…

Helium and hydrogen recombination lines observed in low-metallicity, extragalactic, HII regions provide the data used to infer the primordial helium mass fraction, Y_P. In deriving abundances from observations, the correction for unseen…