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Aims.We present the first large, unbiased sample of Lyman Break Galaxies (LBGs) at $z \sim 1$. Far ultraviolet-dropout (1530 Å) galaxies in the Chandra Deep Field South have been selected using GALEXdata. This first large sample in the $z \sim 1$universe provides us with a high quality reference sample of LBGs. Methods.We analyzed the sample from the UV to the IR using GALEX, SPITZER, ESOand HSTdata.Results.The morphology (obtained from GOODS data) of 75% of our LBGs is consistent with a disk. The vast majority of LBGs with an IR detection are also Luminous Infrared Galaxies (LIRGs). As a class, the galaxies not detected at 24 μm are an order of magnitude fainter relative to the UV compared with those detected individually, suggesting that there may be two types of behavior within the sample. For the IR-bright galaxies, there is an apparent upper limit for the UV dust attenuation and this upper limit is anti-correlated with the observed UV luminosity. Previous estimates of dust attenuations based on the ultraviolet slope are compared to new ones based on the FIR/UV ratio (for LBGs detected at 24 μm), which is usually a more reliable estimator. Depending on the calibration we use to estimate the total IR luminosity, β-based attenuations AFUVare larger by 0.2 to 0.6 mag. than the ones estimated from FIR/UV ratio. Finally, for IR-bright LBGs, median estimated β-based SFRs are 2-3 times larger than the total SFRs estimated as ${\it SFR}_{\rm TOT} = {\it SFR}_{\rm UV} + {\it SFR}_{\rm IR}$while IR-based SFRs provide values below ${\it SFR}_{\rm TOT}$by 15-20%. We use a stacking method to statistically constrain the $24~\mu$m flux of LBGs non individually detected. The results suggest that these LBGs do not contain large amounts of dust.

We present BAX, Base de Données Amas de Galaxies X (http://bax.ast.obs-mip.fr), a multi-wavelength database dedicated to X-ray clusters and groups of galaxies allowing detailed information retrieval. BAX is designed to support astronomical research by providing access to published measurements of the main physical quantities and to the related bibliographic references: basic data stored in the database are cluster/group identifiers, equatorial coordinates, redshift, flux, X-ray luminosity (in the ROSAT band) and temperature, and links to additional linked parameters (in X-rays, such as spatial profile parameters, as well as SZ parameters of the hot gas, lensing measurements, and data at other wavelengths, such as optical and radio). The clusters and groups in BAX can be queried by the basic parameters as well as the linked parameters or combinations of these. We expect BAX to become an important tool for the astronomical community. BAX will optimize various aspects of the scientific analysis of X-ray clusters and groups of galaxies, from proposal planning to data collection, interpretation and publication, from both ground based facilities like MEGACAM (CFHT), VIRMOS (VLT) and space missions like XMM-Newton, Chandra and Planck.

We present high-precision and well sampled BVRIJKlight curves and radial velocity curves for a sample of five Cepheids in the SMC. In addition we present radial velocity curves for three Cepheids in the LMC. The low-metallicity ($\mbox{[Fe/H]}\,\approx -0.7$) SMC stars have been selected for use in a Baade-Wesselink type analysis to constrain the metallicity effect on the Cepheid Period-Luminosity relation. The stars have periods of around 15 days so they are similar to the Cepheids observed by the Extragalactic Distance Scale Key Project on the Hubble Space Telescope. We show that the stars are representative of the SMC Cepheid population at that period and thus will provide a good sample for the proposed analysis. The actual Baade-Wesselink analysis is presented in a companion paper.

We present deep maps of dust emission from the edge-on spiral galaxy NGC 891, obtained with the ISOPHOT instrument on board the Infrared Space Observatory in broad band filters with reference wavelengths centered on 170 and 200 ${\mu}$m. Using new processing methods to remove the effects of detector transients from the data, we detect cold dust at high dynamic range. The observed surface brightness distribution and colour profile of the far-infrared (FIR) emission are found to be in good agreement with predictions for their counterparts derived from the model of Popescu et al. (2000a). Thus, NGC 891 is the first galaxy for which an intrinsic distribution of dust and stars could be found which simultaneously accounts for both the optical/near-IR and FIR morphologies.

The Great Observatories All-Sky LIRG Survey (GOALS20 ) combines data from NASA's Spitzer Space Telescope,Chandra X-Ray Observatory,Hubble Space Telescope(HST), and Galaxy Evolution Explorer(GALEX) observatories, together with ground-based data, into a comprehensive imaging and spectroscopic survey of over 200 low-redshift (z< 0.088), Luminous Infrared Galaxies (LIRGs). The LIRGs are a complete subset of the IRASRevised Bright Galaxy Sample (RBGS), which comprises 629 extragalactic objects with 60 ?m flux densities above 5.24 Jy, and Galactic latitudes above five degrees. The LIRGs targeted in GOALS span the full range of nuclear spectral types defined via traditional optical line-ratio diagrams (type-1 and type-2 AGN, LINERs, and starbursts) as well as interaction stages (major mergers, minor mergers, and isolated galaxies). They provide an unbiased picture of the processes responsible for enhanced infrared emission in galaxies in the local Universe. As an example of the analytic power of the multiwavelength GOALS data set, we present Spitzer, Chandra, HST,and GALEXimages and spectra for the interacting system VV 340 (IRASF14547 + 2449). The SpitzerMIPS imaging data indicates that between 80-95% of the total far-infrared emission (or about 5 × 1011L?) originates in VV 340 north. While the SpitzerIRAC colors of VV 340 north and south are consistent with star-forming galaxies, both the SpitzerIRS and ChandraACIS data indicate the presence of an AGN in VV 340 north. The observed line fluxes, without correction for extinction, imply that the AGN accounts for less than 10%-20% of the observed infrared emission. The X-ray data are consistent with a heavily absorbed (NH?1024cm-2) AGN. The GALEX far and near-UV fluxes imply a extremely large infrared "excess" (IRX) for the system (FIR/Ffuv? 81) which is well above the correlation seen in starburst galaxies. Most of this excess is driven by VV 340 N, which has an IR excess of nearly 400. The VV 340 system seems to be comprised of two very different galaxies: an infrared luminous edge-on galaxy (VV 340 north) that dominates the long-wavelength emission from the system, which hosts a buried AGN; and a face-on starburst (VV 340 south) that dominates the short-wavelength emission.

We present the results of near-infrared observations of extragalactic Cepheids made with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope(HST). The variables are located in the galaxies IC 1613, IC 4182, M31, M81, M101, NGC 925, NGC 1365, NGC 2090, NGC 3198, NGC 3621, NGC 4496A, and NGC 4536. All fields were observed in the F160W bandpass; additional images were obtained in the F110W and F205W filters. Photometry was performed using the DAOPHOT II/ALLSTAR package. Self-consistent distance moduli and color excesses were obtained by fitting period-luminosity relations in the H, I, and Vbands. Our results support the assumption of a standard reddening law adopted by the HSTKey Project on the Extragalactic Distance Scale. A companion paper will determine true distance moduli and explore the effects of metallicity on the Cepheid distance scale.

New positions (good to ± 15 arcsec), revised sizes, and sample cross-identifications are presented for dwarf galaxies and published by Mailyan (1973). Of the 104 originally catalogued galaxies we were able to recover only 100, despite an extensive search of the red and blue POSS prints. Over half of the recovered objects were found to correspond to previously catalogued galaxies; few if any of these are dwarf spheroidal galaxies, but rather mostly dwarf irregulars of low surface brightness.

A 'phase-shift' technique for detecting photometric companions to cepheids is applied to 202 variables. The inferred incidence of duplicity is 35 plus or minus 5%. An earlier 'color-color loop' method suggested 20%-27% duplicity. However, when positive results are required of both methods for a given star, the incidence falls to 15%. This lack of detailed agreement, as well as an apparent correlation of duplicity with period, suggests neither method is infallible.

The discovery of a very sparse star cluster in the constellation Hydra in the southern sky is reported. The cluster was found during a search for peculiar galaxies in a plate from the ESO/SRC IIIa-J Southern Sky Survey, observed at a magnification of 20X. Designated AM-4, the cluster contains approximately 50 stars within a 110 arcsec diameter. Assumptions that the brightest stars in the cluster are red giants and that absorption in the direction of the cluster is low lead to the estimate that the cluster is over 200 kpc distant, and so might be intrinsically rich. The chance discovery of the cluster points up the need for more detailed surveys to determine the actual density of extreme halo or intergalactic globular clusters.

We present a self-consistent model of the spectral energy distributions (SEDs) of spiral galaxies from the ultraviolet (UV) to the mid-infrared (MIR)/far-infrared (FIR)/submillimeter (submm) based on a full radiative transfer calculation of the propagation of starlight in galaxy disks. This model predicts not only the total integrated energy absorbed in the UV/optical and re-emitted in the infrared/submm, but also the colours of the dust emission based on an explicit calculation of the strength and colour of the UV/optical radiation fields heating the dust, and incorporating a full calculation of the stochastic heating of small dust grains and PAH molecules.