Related papers: Which Stars are Ionizing the Orion Nebula ?
We present the analysis of an XMM-Newton observation of the M17 nebula. The X-ray point source population consists of massive O-type stars and a population of probable low-mass pre-main sequence stars. CEN1a,b and OI352, the X-ray brightest…
The emission spectra and the ionization structure of the low ionization stages of iron, Fe I--IV, in gaseous nebulae are studied. This work includes: (i) new atomic data: photoionization cross sections, total e-ion recombination rates,…
The aim of this work is to characterize the stellar population between Earth and the Orion A molecular cloud where the well known star formation benchmark Orion Nebula Cluster (ONC) is embedded. We use the denser regions the Orion A cloud…
We present a new 11.7 micron mosaic image of the Orion nebula obtained with T-ReCS on Gemini South. The map includes the BN/KL region, the Trapezium, and OMC-1 South. Excluding BN/KL, we detect 91 point sources, with 27 known proplyds and…
The star forming region of the Orion Nebula (ONC) is ideal to study the stellar dynamics of young stars in a clustered environment. Using Gaia DR2 we search for the pre-main sequence stars with unusually high proper motions that may be…
We discuss the sources which are likely to dominate the ionizing field throughout the Local Group. In terms of the limiting flux to produce detectable H-alpha emission (4-10 x 10**3 phot/cm**2/s), the four dominant galaxies (M31, Galaxy,…
Massive stars born in star clusters terminate star cluster formation by ionizing the surrounding gas. This process is considered to be prevalent in young star clusters containing massive stars. The Orion Nebula is an excellent example…
Most stars form as members of large associations within dense, very cold (10-100 K) molecular clouds. The nearby giant molecular cloud in Orion hosts several thousand stars of ages less than a few million years, many of which are located in…
The Trifid Nebula is a young HII region recently rediscovered as a "pre-Orion" star forming region, containing protostars undergoing violent mass ejections visible in optical jets as seen in images from the Infrared Space Observatory and…
The Orion Bar is the archetypal edge-on molecular cloud surface illuminated by strong ultraviolet radiation from nearby massive stars. Owing to the close distance to Orion (about 1,350 light-year), the effects of stellar feedback on the…
The predicted emission spectrum of NII is compared with observations of permitted lines in the Orion nebula. Conventional nebular models show that the intensities of the more intense lines can be explained by fluorescence of starlight…
In this work, we report the discovery of a candidate planetary-mass object with a photoevaporating protoplanetary disk, Proplyd 133-353, which is near the massive star $\theta^{1}$ Ori C at the center of the Orion Nebula Cluster (ONC). The…
Massive stars inject mechanical and radiative energy into the surrounding environment, which stirs it up, heats the gas, produces cloud and intercloud phases in the interstellar medium, and disrupts molecular clouds (the birth sites of new…
Following our study on the incidence, morphology and kinematics of the ionised gas in early-type galaxies we now address the question of what is powering the observed nebular emission. To constrain the likely sources of gas excitation, we…
Following the Chandra Orion Ultradeep Project (COUP) observation, we have studied the chemical composition of the hot plasma in a sample of 146 X-ray bright pre-main sequence stars in the Orion Nebula Cluster. We report measurements of…
Due to its proximity to the Earth and its nearly edge-on geometry, the Orion Bar provides an excellent testbed for detailed models of the structure of HII regions and the surrounding photon-dominated regions. In the present study, a…
A survey of diffuse interstellar sight lines observed with the Far Ultraviolet Spectroscopic Explorer has led to the serendipitous discovery of a high-ionization nebula around the hot white dwarf KPD 0005+5106. The nebula has an OVI 1032A…
The detection and first identification of the deuterium Balmer emission lines, D-alpha and D-beta, in the core of the Orion Nebula is reported. Observations were conducted at the 3.6m Canada-France-Hawaii Telescope, using the Echelle…
A strong emission line at 2.8935 mu discovered by Rubin et al. (2001) in an ISO SWS02 spectrum of the Orion Nebula is identified as the 4p - 4s multiplet of the O I triplets. Line formation is due to de-excitation cascades following…
The reliability of C, N, and O abundances determined from the C II, N II, and O II lines in the main sequence (MS) early B- and late O-type stars is examined. This analysis is based on a fact of primary importance for this problem: the C…