Search Publications
Mid-infrared diagnostics to distinguish AGNs from starbursts
Cesarsky, C.; Madden, S. C.; Sauvage, M. +5 more
We present new mid-infrared (MIR) diagnostics to distinguish emission of active galactic nuclei (AGN) from that originating in starburst regions. Our method uses empirical spectroscopic criteria based on the fact that MIR emission from star forming or active galaxies arises mostly from HII regions, photo-dissociation regions (PDRs) and AGNs. The a…
ISO-SWS spectra of galaxies: Continuum and features
Lutz, D.; Genzel, R.; Sturm, E. +5 more
We present an inventory of mid-infrared spectral features detected in high resolution (R ~ 1500) ISO-SWS 2.4-45mu m spectra of the galaxies
An ISOCAM absorption survey of the structure of pre-stellar cloud cores
Abergel, A.; Puget, J. -L.; Bontemps, S. +3 more
We present the results of a mid-infrared (lambda =~ 7 mu m) imaging survey of a sample of 24 starless dense cores carried out at an angular resolution of 6arcsec with the ISOCAM camera aboard the Infrared Space Observatory (ISO). The targeted cores are believed to be pre-stellar in nature and to represent the initial conditions of low-mass, isolat…
2.5-11 micron spectroscopy and imaging of AGNs. Implication for unification schemes
Altieri, B.; Clavel, J.; Metcalfe, L. +6 more
We present low resolution spectrophotometric and imaging ISO observations of a sample of 57 AGNs and one non-active SB galaxy over the 2.5-11 mu m range. The sample is about equally divided into type I (<= 1.5; 28 sources) and type II (> 1.5; 29 sources) objects. The mid-IR (MIR) spectra of type I (Sf1) and type II (Sf2) objects are statisti…
Implications of the cosmic infrared background for light production and the star formation history in the Universe
Lagache, G.; Puget, J. L.; Gispert, R.
The Cosmic Background due to the integrated radiation from galaxies over the whole life of the Universe is reviewed. We find that this background is well constrained by measurements. The total power in the background is in the range 60-93 nWm-2sr-1. The data show the existence of a minimum separating the direct stellar radiat…
The structure of the collapsing envelope around the low-mass protostar IRAS 16293-2422
Ceccarelli, C.; Caux, E.; Tielens, A. G. G. M. +4 more
Using H2O, OI and SiO data, we derive the structure of the collapsing envelope around the low-mass protostar IRAS16293-2422 down to r ~ 30 AU. With an accurate model which computes self-consistently the chemical composition, thermal balance and line emission from a collapsing envelope (Ceccarelli et al. 1996), we find that IRAS16293-242…
Probing the brown dwarf population of the Chamaeleon I star forming region
Neuhäuser, R.; Comerón, F.; Kaas, A. A.
We present observations of a sample of 13 very low mass stars and brown dwarfs in the central region of the Chamaeleon I star forming cloud. The observations include slitless spectroscopy around Hα to identify new members, low resolution long-slit visible and near-infrared spectroscopy, deep ROSAT PSPC X-ray observations, and ISOCAM mid-infrared o…
ISO-SWS observations of OMC-1: H_2 and fine structure lines
Bertoldi, F.; Drapatz, S.; Rosenthal, D.
Using the Short-Wavelength-Spectrometer on the Infrared Space Observatory (ISO), we obtained near- and mid-infrared spectra toward the brightest H_2 emission peak of the Orion OMC-1 outflow. A wealth of emission and absorption features were detected, dominated by 56 H_2 ro-vibrational and pure rotational lines reaching from H_2 0-0 S(1) to 0-0 S(2…
The C-C-C bending modes of PAHs: a new emission plateau from 15 to 20 µm
Waters, L. B. F. M.; Hony, S.; Tielens, A. G. G. M. +9 more
We have obtained 2.5-45 mu m spectra of a sample of compact H ii regions, YSOs and evolved stars in order to study the origin and evolution of interstellar Polycyclic Aromatic Hydrocarbon molecules (PAHs). Besides the well-known, strong PAH bands at 3.3, 6.2, 7.7, 8.6, and 11.2 mu m, these spectra reveal for the first time, a ubiquitous emission p…
ISO-SWS spectroscopy of gas-phase C_2H_2 and HCN toward massive young stellar objects
van Dishoeck, E. F.; Lahuis, F.
Observations of gas-phase C_2H_2 and HCN along the line of sight toward a large sample of deeply embedded massive young stellar objects (YSOs) have been performed using the Short Wavelength Spectrometer on board the Infrared Space Observatory. The nu_5 vibration-rotation band of C_2H_2 around 13.7 µm and the nu_2 band of HCN around 14.0 &mic…