We report the study of ISOGAL fields in the outer galactic bulge. We have combined 7 and 15 μm ISOCAM observations with DENIS IJKs near-infrared data to determine the nature of the sources and the interstellar extinction. Most of the ISOGAL sources show evolution of mass-loss rates in the range 10-8 to 10-6 M⊙/year. Most of the detected sources are red giants above the RGB tip; a few of them show an excess inand J - Ks-[15] colors. These sources are detected as AGB stars with large mass-loss rates.

Strip scanning measurements with crossing position angleshave been carried out at 120 μm and 180 μmwith the ISOPHOT instrument aboard ISO to observe extended FIRemission from six Abell clusters. Theraw I120 μm/I180 μm surface brightness ratioincluding zodiacal light shows a bump towards Abell 1656 (Coma), dipstowards Abell 262 and Abell 2670, and is without an unambiguousfeature towards Abell 400, Abell 496, and Abell 4038. The subtractionof the zodiacal light leaves the bump towards Abell 1656 stillpresent, while the dips towards Abell 262 and Abell 2670 are no longerdiscernible. This behavior can be reconciled in Abell 1656 with alocalized excess of emitting material outside the Galaxy withproperties different from the galactic foreground cirrus, and in Abell262 and Abell 2670 with galactic cirrus structures localized on theline-of-sight to these clusters. At 120 μmthe excesstowards Abell 1656 (Coma) is ≈ 0.2 MJy/sr, with an integratedexcess flux within the central region of 10'-15' diameter of ≈ 2.8 Jy. It is interpreted asbeing due to thermal emission from intracluster dust distributed inthe hot X-ray emitting intracluster medium. Only a rough estimate ofthe associated dust mass of MD ≈ 107 M⊙ can be derived, since the dust temperature is poorly constrained. Thevisual extinction associated with this dust mass is negligible(AV << 0.1 mag) and much smaller than claimed fromoptical observations. No evidence for intracluster dust is found inthe other five clusters observed. The rather low inferred dust massin Abell 1656 together with the absence of a signature forintracluster dust in the other clusters observed indicatesthatintracluster dust is likely not responsible for the excess X-rayabsorption seen in cooling flow clusters. These observations therebyrepresent a further unsuccessful attempt in detecting the presumed final stage of the cooling flow material, in accord with quite a number of previous studies. Finally, the observed dimming of the high - redshift supernovae is unlikely be attributable to extinction causedby dust in the intracluster or even a presumed intercluster medium.

This paper reviews what we know on the ExtragalacticBackground (EB)and on the nature of its contributing galaxies in the infrared (IR) and sub-millimeter (sub-mm).I first present the EB observationnal constraints, their main cosmologicalimplications,and results from deep IR and sub-mm surveys.Then, using a phenomelogical model of IR galaxy evolution,I show how these data constrain the evolution of IR galaxies,in particular the luminosity densityand the luminosity function.And finally, I briefly review the detection of the IR EB fluctuations and theirpotential implications.

Faint submillimeter sources detected with JCMT/SCUBAhave faced an identification problem due to their broad beam profiles.Here we propose a new method to identify these sourcesat the mid-infrared utilizing a finer point spread function.ISOCAM has provided us a very deep 6.7 μm image of the Hawaii Deep Field SSA13.For all three 850 μm sources in this field,we have found their 6.7 μm counterparts.All of them have been identified with interacting galaxy pairs at the optical.Two of the pairs are very faint and red (I>24, I - K > 4),one of the two has the hard X-ray detection with Chandra.Assuming an Arp 220 SED,we have found a typical redshift of z ~ 2.This requiresthat the sources should be a few times more luminous than Arp 220.It appears that extremely high star formation ratesare occurring in galaxies at high redshiftwith massive stellar contents already in place.

We present measurements of the fine structure transitions ofatomic carbon, and of the submillimeter rotational lines of carbon monoxidein a variety of external galaxies. We discuss the relativecontributions of atomic carbon and carbon monoxide for the coolingof molecular gas in these galaxies, and how these linescan be used to determine the physical conditions in theemitting gas.

The "Herschel Space Observatory" (formerly known as the "FarInfraRed and Submillimetre Telescope" - FIRST) is thefourth cornerstone mission in the European Space Agency (ESA)science programme. It will perform imaging photometry andspectroscopy in the far infrared and submillimetre part of thespectrum, covering approximately the 57-670 μm range. The key science objectives emphasize current questions connected to the formation of galaxies and stars, however, having unique capabilities in several ways, Herschel will be a facility available to the entire astronomical community. Because Herschel to some extent will be itsown pathfinder, the issue of instrument calibration and dataprocessing timescales has special importance. Herschel will carry a 3.5 metre diameter passively cooled telescope.The science payload complement - two cameras/medium resolutionspectrometers (PACS and SPIRE) and a very high resolution heterodynespectrometer (HIFI) - will be housed in a superfluid heliumcryostat. Herschel will be placed in a transfer trajectory towards its operational orbit around the Earth-Sun L2 pointby an Ariane 5 (shared with the ESA cosmic background mappingmission Planck) in early 2007. Once operational Herschel will offer aminimum of 3 years of routine observations; roughly2/3 of the available observing time is open to the generalastronomical community through a competitive proposalprocedure.

The Cosmic Microwave Background Radiation is the oldest photon radiation that can be observed, having been emitted when the Universe was about 300 000 year old. It is a blackbody at 2.73 K, and is almost perfectly isotropic, the anisotropies being about one part to 100 000. However, these anisotropies, detected by the COBE satellite in 1992, constrain the cosmological parameters such as the curvature of the Universe. Archeops is a balloon-borne experiment designed to map these anisotropies. The instrument is composed of a 1.5 m telescope and bolometers cooled at 85 mK to detect radiation between 150 and 550 GHz. To lower parasitic signals, the instrument is borne by a stratospheric balloon during the arctic night. This instrument is also a preparation for the Planck satellite mission, as its design is similar to HFI. We discuss here the results of the first scientific flight from Esrange (near Kiruna, Sweden) to Russia on January 29th 2001,which led to a 22% (sub)millimetre sky coverage unprecedented at thisresolution. Here, we put some emphasis on interstellar dust foregroundemission observations.

The Japanese infrared space missions in the past and the future are briefly summarized with some historical and strategic view points. Starting with simple ground based observations, we have been putting an emphasis on space missions with less affected by the poor Japanese climate conditions for infrared observations using balloons, rockets and satellites. Focusing on diffuse infrared emissions, which are favorably observable by small and simple instruments, we have succeeded in getting unique results of zodiacal light, Galactic and extragalactic emissions as well as the cosmic background radiation.

The ASTRO-F (also known as Infrared Imaging Surveyor: IRIS) is the second infrared satellitemission of the Institute of Space and Astronautical Science, Japan tobe launched early 2004 with the M-V rocket and is planned asa second generation infrared sky survey mission. It has a 67-cm aperture telescope and is cooled by 170-liter liquid helium andStirling-cycle coolers. Two scientific instrumentsshare the focal plane. The infrared camera (IRC) covers 2 to 26 μm rangewith large two-dimensional arrays in the imaging and low-resolution spectroscopicmodes and will perform deep sky surveys of selected areas of thesky with a wide field of view (10' × 10') at unprecedented sensitivity.The far-infrared Surveyor (FIS), consisting ofan imaging scanner and a Fourier transform spectrometer, covers 50 to 200 μm range and makes a wholesky survey in four far-infrared bands, which is higher by more than 10 in sensitivity(20-110 mJy), better by several in the spatial resolution (30''-50''),and longer in the spectral coverage (200 μm) than IRAS. A brief description and the current statusof the ASTRO-F mission are presented.

The Stratospheric Observatory For Infrared Astronomy(SOFIA) is a 2.5 m telescope which will fly in a Boeing 747SP, commencing operationin late summer 2004. SOFIA is a jointAmerican/German project and formost of this decade it will be the largest far-infrared telescope.SOFIA will have a suite of instruments available to the astronomicalcommunity, including the High-resolution Airborne Wide-band Camera(HAWC) - its facility far-infraredcamera.

This paper presents the scientific objectives and technical aspects ofthe balloon-borne Experiment for Large Infrared Survey Astronomy(ELISA). The emphasis is put upon the synergies existing between theELISA project and future space missions, both with respect toscientific and technical aspects. ELISA is a small balloon projectfor an experiment dedicated to measure the Far-Infrared toSub-millimeter continuum emission of Galactic dust over a largefraction of the sky, with unprecedented sensitivity and angularresolution. The primary mirror of the telescope, similar to the oneused for the Top-Hat mission, will have a diameter of 1 m, ensuring anangular resolution of about 3.5'. Bolometer arrays will be used infour photometric bands centered at 170, 240, 400, and 650 μm andproviding a 22' × 45' instantaneous field of view per channel. A liquid He cryostat will host the cold optics, including thesecondary mirror of the telescope, as well as the detectors, whichwill be cooled to 0.3 K using an 3He close-cycle fridge. Mapping ofthe sky will be accomplished by rotating the gondola over a largeazimuth range (up to 60° amplitude). The pointing of theexperiment will be maintained to a constant elevation during theazimuth scans through a feed back loop using the signal from a largeformat, fast stellar sensor, operating day and night. The scientificgoal of the experiment is to map the diffuse Sub-millimeter emissionalong a large fraction of the Milky Way. The astronomical dataobtained will be used to derive the emission properties of the dustgrains in the Interstellar Medium (ISM), such as their temperature andemissivity. It will also allow to systematically measure thepolarization of the dust emission. It should also lead to thedetection of a few thousand point sources such as newly formed starsand distant galaxies. In addition to these goals, the ELISA projectwill serve as a test bed for the detector technology that will be usedfor the HERSCHEL space mission to be launched in 2007. The ELISA datawill be made available to help calibrate the observations ofHERSCHEL and PLANCK and to plan the large-scale surveys to beundertaken with HERSCHEL. Owing to these objectives, 3 flights of theELISA experiment, are foreseenin the period from 2004 to 2006. The ELISA project is carried out byan international collaboration including France (CESR, IAS, CEA,CNES),The Netherlands (SSD/ESTEC), Denmark (DSRI), UK (Cardiff Univ.).

The Submillimetron is the international project of the spacetelescope for full sky survey in submillimeter region 0.15-1.5 mmusing facilities of the Russian segment of the InternationalSpace Station (ISS). A free flying module for the project isunder development in corporation Energia. Periodic docking ofthe module to the ISS gives possibility to combine low cost withreliability, refilling, repairment and maintenance. The conceptof the telescope combines a 0.6 m mirror cooled to liquid heliumtemperature with a novel type of microbolometers arrays developedat Chalmers University (Sweden). This combination gives uniquepossibility to realize background limited sensitivity about10-18 W/Hz-1/2 in the spectral minimum of theextraterrestrial background near frequency 1 THz between peaks ofgalactic dust emission and CMB. The angular resolution of theinstrument is about 1 arcmin, field of view ~1°.

The balloon-borne submillimeter instrument PRONAOS has observed one square degree areas towards the Orion and M 17 molecular clouds. The 2'-3.5' resolutionmaps obtained in four wide wavelength bands between 200 μm and 600 μm, exhibit the dust distribution in these regions. We analyze the temperature andspectral index of the dust, and we show the anticorrelation between these two parameters. We derive estimations of the ISM column densities and masses in these regions.

We present initial results of a deep mid-infrared surveyconducted in the high galactic latitude field SSA13 with ISO.We have surveyed through the broad band filterLW2 (5-8.5 μm)of the mid-infrared camera ISOCAMto probe the near-infrared light at high redshift.The 80% completeness limit for point sources in the central6 arcmin2 reaches 10 μJy at 6.7 μm.65 sources are detected down to 6 μJy in 16 arcmin2.The integral galaxy number countsare 1.4 × 104 deg-2at 10 μJy with the slope of -1.5.The integrated 6.7 μm light down to 6 μJyis estimated as 0.43 nWm-2sr-1.Our counts are consistent withthe results in the HDF andthe model predictionbased on the K band local luminosity function.It suggests thatthe majority of the detected sources areE/S0 galaxies at z>1.

Although ground-based submm facilities havebeen operating since more than a decade now, very few information hasbeen collected at the lower frequencies offered by Herschel. Additional observations need to be conducted prior to launch to assessthe reliability of a given source to be used as calibrator forphotometry and/or spectroscopy.In this paper we present some of the drivers for the preparation ofsuch a database on the basis of pioneering and long-term observing campaigns.

Compact Antenna Test-Ranges (CATR) represent a highstandard of state-of-the-art test facilities with a fast and realtime measurement capability up to the sub-millimeter range. Futurescientific observation instruments of ESA such as the Planck andHerschel telescopes are working within this frequency ranges and require a high measurement accuracy for large antenna apertures. This present paper shows the first modelling of a large CATR atmillimetre frequency. The software used in this paper is GRASP8(from TICRA), and specially the recent Multi-ReflectorGeometrical Theory of Diffraction upgrade (MR-GTD thereafter).

We present the results of an experimental study of the structuraleffects induced by Lyman-α UV photons in crystalline water ice atlow temperature carried out by using in situ infrared spectroscopy. Westudied the evolution, under UV irradiation, of the 3 micron bandprofile. We found that an UV dose of few eV per water ice molecule isenough to fully amorphize the structure at the investigated temperatureof 16 K. The evolution of the 3 micron feature during UV irradiation iscompared with that observed for fast ion irradiation carried out in thesame experimental set-up. Both photons and fast ions are present inspace, they can induce variations in the profile of the3 micron bandof crystalline water ice. Thus these effects must be considered when oneattempts to deduce, from the profile of the observed ice band,information on the temperature history of the responsible dust.

We present an extinction map of the Polaris molecular cirrus cloud derivedfrom star counts and compare it with the Schlegel et al. [13]extinction map derived from the far-infrared dust opacity. We find that,within the Polaris cloud, the Schlegel et al. [13] AV values are,on average, a factor 2 higher than the star count values. We propose that thisdiscrepancy results from a difference in τFIR/AV between the diffuseatomic medium and the Polaris cloud. We use the difference in spectral energydistribution, warm for the diffuse atomic medium, cold for the Polaris cloud,to separate their respective contribution to the line of sight integratedinfrared emission and find that the τFIR/AV of cold dust in Polarisis on average 4 times higher than the Schlegel et al. [13] value fordust in atomic cirrus. This change in dust property could be interpreted bya growth of fluffy particles within low opacity molecular cirrus clouds suchas Polaris. Our work suggests that variations in dust emissivity must betaken into account to estimate AV from dust emission wherever coldinfrared emission is present (i.e. molecular clouds).

This paper reports the first results obtained on thephotodissociation of the isolated PAH cations 12C24H+12,13C12C23H+12 and 12C24H+10, usingthe astrochemistry experimental set-up PIRENEA.The dissociation patterns of these ions involvethe loss of pairs of hydrogen atoms. A first interpretation indicates that the-H2 dissociation path is favoured compared to the -H path in ourexperimental conditions. These results might have important implicationson the formation of H2 in the interstellar medium.