Search Publications
Interstellar Ice: The Infrared Space Observatory Legacy
Whittet, D. C. B.; Tielens, A. G. G. M.; Boogert, A. C. A. +1 more
We present 2.5-30 µm spectra from the Short-Wavelength Spectrometer of the Infrared Space Observatory for a total of 23 sources. The sources include embedded young stellar objects spanning a wide range of mass and luminosity, together with field stars sampling quiescent dark clouds and the diffuse interstellar medium. Expanding on results of…
The Absence of Crystalline Silicates in the Diffuse Interstellar Medium
Tielens, A. G. G. M.; Kemper, F.; Vriend, W. J.
Infrared spectroscopy provides a direct handle on the composition and structure of interstellar dust. We have studied the dust along the line of sight toward the Galactic center using Short Wavelength Spectrometer data obtained with the Infrared Space Observatory (ISO). We focused on the wavelength region from 8 to 13 µm, which is dominated …
The 24 Micron Source Counts in Deep Spitzer Space Telescope Surveys
Rigby, J. R.; Le Floc'h, E.; Dole, H. +20 more
Galaxy source counts in the infrared provide strong constraints on the evolution of the bolometric energy output from distant galaxy populations. We present the results from deep 24 µm imaging from Spitzer surveys, which include ~5×104 sources to an 80% completeness of ~=60 µJy. The 24 µm counts rapidly rise at near-Eu…
The relation between AGN hard X-ray emission and mid-infrared continuum from ISO spectra: Scatter and unification aspects
Lutz, D.; Maiolino, R.; Moorwood, A. F. M. +1 more
We use mid-infrared spectral decomposition to separate the 6 µm mid-infrared AGN continuum from the host emission in the ISO low resolution spectra of 71 active galaxies and compare the results to observed and intrinsic 2-10 keV hard X-ray fluxes from the literature. We find a correlation between mid-infrared luminosity and absorption correc…
The Anatomy of Star Formation in NGC 300
Helou, G.; Roussel, H.; Fazio, G. G. +19 more
The Spitzer Space Telescope was used to study the mid- to far-infrared properties of NGC 300 and to compare dust emission to Hα to elucidate the heating of the interstellar medium (ISM) and the star formation cycle at scales smaller than 100 pc. The new data allow us to discern clear differences in the spatial distribution of 8 µm dust emiss…
ISO Spectroscopy of Gas and Dust: From Molecular Clouds to Protoplanetary Disks
van Dishoeck, Ewine F.
Observations of interstellar gas-phase and solid-state species in the 2.4 200 m range obtained with the spectrometers on board the Infrared Space Observatory (ISO) are reviewed. Lines and bands caused by ices, polycyclic aromatic hydrocarbons, silicates, and gas-phase atoms and molecules (in particular H2, CO, H2O, OH, and CO…
The Profiles of the 3-12 Micron Polycyclic Aromatic Hydrocarbon Features
Hony, S.; Tielens, A. G. G. M.; Allamandola, L. J. +4 more
We present spectra of the 3.3 µm and 11.2 µm polycyclic aromatic hydrocarbon (PAH) features of a large number of stellar sources, planetary nebulae, reflection nebulae, H II regions, and galaxies, obtained with Infrared Space Observatory Short Wavelength Spectrometer. Clear variations are present in the profiles of these features. Most…
Polycyclic Aromatic Hydrocarbon Contribution to the Infrared Output Energy of the Universe at z ~= 2
Le Floc'h, E.; Dole, H.; Lagache, G. +10 more
We present an updated phenomenological galaxy evolution model to fit the Spitzer 24, 70, and 160 µm number counts, as well as all the previous mid- and far-infrared observations. Only a minor change of the comoving luminosity density distribution in the previous model (Lagache, Dole, & Puget), combined with a slight modification of the s…
ISO spectroscopy of disks around Herbig Ae/Be stars
van den Ancker, M. E.; Acke, B.
We have investigated the infrared spectra of all 46 Herbig Ae/Be stars for which spectroscopic data are available in the ISO data archive. Our quantitative analysis of these spectra focuses on the emission bands at 3.3, 6.2, ``7.7'', 8.6 and 11.2 micron, linked to polycyclic aromatic hydrocarbons (PAHs), the nanodiamond-related features at 3.4 and…
Some empirical estimates of the H2 formation rate in photon-dominated regions
Boulanger, F.; Walmsley, C. M.; Habart, E. +2 more
We combine recent ISO observations of the vibrational ground state lines of H2 towards Photon-Dominated Regions (PDRs) with observations of vibrationally excited states made with ground-based telescopes in order to constrain the formation rate of H2 on grain surfaces under the physiconditions in the layers responsible for H