Related papers: Molecular Hydrogen Fluorescence in the Eridanus Su…
New subarcsecond FUV observations of T Tau with HST/STIS show spatially resolved structures in the 2"x2" area around the star. The structures show in multiline emission of fluorescent H_2 pumped by Lyman alpha. One emission structure…
The energy density of cosmic neutrinos measured by IceCube matches the one observed by Fermi in extragalactic photons that predominantly originate in blazars. This has inspired attempts to match Fermi sources with IceCube neutrinos. A…
We present high-resolution spectroscopy and images of a photodissociation region (PDR) in M16 obtained during commissioning of NIRSPEC on the Keck II telescope. PDRs play a significant role in regulating star formation, and M16 offers the…
We report the first observations of far-ultraviolet (FUV: 1000 -- 1150 \AA) diffuse radiation from the Small Magellanic Cloud (SMC) using observations from the {\em Far Ultraviolet Spectroscopic Explorer (FUSE)}. The strength of FUV diffuse…
The hydrogen fluoride (HF) molecule is seen in absorption in the interstellar medium (ISM) along many lines of sight. Surprisingly, it is observed in emission toward the Orion Bar, which is an interface between the ionized region around the…
This paper continues our study of the behaviour of near infrared helium recombination lines in planetary nebula. We find that the 1.7007um 4^3D-3^3P HeI line is a good measure of the HeI recombination rate, since it varies smoothly with the…
The origin of rovibrational H_2 emission in the central galaxies of cooling flow clusters is poorly understood. Here we address this issue using data from our near-infrared spectroscopic survey of 32 of the most line luminous such systems,…
The Orion-Eridanus superbubble has been blown by supernovae and supersonic winds of the massive stars in the Orion OB associations. The formation history and current structure of the superbubble are still poorly understood. It possibly…
Molecular globules and pillars are spectacular features, found only in the interface region between a molecular cloud and an HII-region. Impacting Far-ultraviolet (FUV) radiation creates photon dominated regions (PDRs) on their surfaces…
Molecular hydrogen line radiation emitted in formation events of first-generation stars are evaluated in a discussion of its detectability by future observational facilities. H_2 luminosity evolution from the onset of prestellar collapse…
A new molecular hydrogen cloud has been identified at z = 3.025 in the absorption-line spectrum of the quasar 0347-3819 observed with the UVES spectrograph at the VLT/Kueyen telescope. At the same redshift numerous metal lines and the DI…
We describe an approach to detecting ionizing radiation that combines the special properties of superfluid helium with the sensitivity of quantum optics techniques. Ionization in liquid helium results in the copious production of metastable…
We discovered Bowen emission arising from a strongly lensed (i.e., with magnification factor $\mu$>20) source hosted in the Sunburst arc at z=2.37. We claim this source is plausibly a transient stellar object and study the unique…
Observations of the high-mass star forming region AFGL 2591 reveal a large abundance of CO+, a molecule known to be enhanced by far UV (FUV) and X-ray irradiation. In chemical models assuming a spherically symmetric envelope, the volume of…
Young massive stars produce Far-UV photons which dissociate the molecular gas on the surfaces of their parent molecular clouds. Of the many dissociation products which result from this ``back-reaction'', atomic hydrogen \HI is one of the…
We investigate the physical and chemical processes at work during the formation of a massive protostar based on the observation of water in an outflow from a very young object previously detected in H2 and SiO in the IRAS 17233-3606 region.…
The Cygnus region is a vast star-forming complex harbouring a population of powerful objects, including massive star clusters and associations, Wolf-Rayet stars, pulsars, and supernova remnants. The multi-wavelength picture is far from…
We derive total (atomic + molecular) hydrogen densities in giant molecular clouds (GMCs) in the nearby spiral galaxy M33 using a method that views the atomic hydrogen near regions of recent star formation as the product of…
The thermochemistry of H2 and HD in non-collapsed, non-reionized primordial gas up to the end of the dark age is investigated with recent radiation-matter and chemical reaction rates taking into account the efficient coolant HD, and the…
We report on laboratory measurements of molecular hydrogen formation and recombination on an olivine slab as a function of surface temperature under conditions relevant to those encountered in the interstellar medium. On the basis of our…