Star formation rates of distant luminous infrared galaxies derived from Halpha and IR luminosities

We present a study of the star formation rate (SFR) for a sample of 16 distant galaxies detected by ISOCAM at 15um in the CFRS0300+00 and CFRS1400+52 fields. Their high quality and intermediate resolution VLT/FORS spectra have allowed a proper correction of the Balmer emission lines from the underlying absorption. Extinction estimates using the Hbeta/Hgamma and the Halpha/Hbeta Balmer decrement are in excellent agreement, providing a robust measurement of the instantaneous SFR based on the extinction-corrected Halpha luminosity. Star formation has also been estimated exploiting the correlations between IR luminosity and those at MIR and radio wavelengths. Our study shows that the relationship between the two SFR estimates follow two distinct regimes: (1) for galaxies with SFRIR below ~ 100Msolar/yr, the SFR deduced from Halpha measurements is a good approximation of the global SFR and (2) for galaxies near of ULIRGs regime, corrected Halpha SFR understimated the SFR by a factor of 1.5 to 2. Our analyses suggest that heavily extincted regions completely hidden in optical bands (such as those found in Arp 220) contribute to less than 20% of the global budget of star formation history up to z=1.Comment: (1) GEPI, Obs. Meudon, France ;(2) CEA-Saclay, France ;(3) ESO, Gemany ;(4) IAC, Spain. To appear in A&

Utilizing Remote Sensing and Digital Image Processing to Delineate the Structural Features in the Eastern Part of the Dead Sea, Jordan

Digital image processing techniques were used for mapping structural features using a medium resolution image (ETM+) from Landsat 7. The aim of this study is to utilize remote sensed data and digital image processing techniques for updating the structural map in the north eastern part of the Dead Sea (Ma’in area), Jordan. The study area is becoming an important target for geological survey activities, mineral exploration and industrial investment. This area was chosen for conducting a study based on satellite imagery interpretation of Landsat Thematic Mapper (ETM+). A special attention has been given in this study to the textural analysis techniques and the methods of image enhancements of Landsat (ETM+) images. As a result, a new lineament map was produced that represents the subsurface geological features and structures using visual interpretation and digital image processing by utilizing different enhancement techniques. A map showing the old structural features at a sub-regional scale has been produced together with a map showing the new structural features as interpreted from Thematic Mapper images

Deep Herschel view of obscured star formation in the Bullet cluster

We use deep, five band (100–500 μm) data from the Herschel Lensing Survey (HLS) to fully constrain the obscured star formation rate, SFR_(FIR), of galaxies in the Bullet cluster (z = 0.296), and a smaller background system (z = 0.35) in the same field. Herschel detects 23 Bullet cluster members with a total SFRFIR = 144±14 M_☉ yr^(-1). On average, the background system contains brighter far-infrared (FIR) galaxies, with ~50% higher SFRFIR (21 galaxies; 207 ± 9 M_☉ yr^(-1)). SFRs extrapolated from 24 μm flux via recent templates (SFR_(24 µm)) agree well with SFRFIR for ~60% of the cluster galaxies. In the remaining ~40%, SFR24 µm underestimates SFR_(FIR) due to a significant excess in observed S_(100)/S_(24) (rest frame S_(75)/S_(18)) compared to templates of the same FIR luminosity

A critical review on the role of food and nutrition in the energy balance

The mass media has increasingly frequently suggested to the general population that specific foods or nutritional schemes are able to affect both human metabolism and energy expenditure, thus facilitating weight loss. This critical review is aimed at assessing available evidence on the roles of nutrients, food and dietary regimens in energy intake and energy expenditure. We queried the National Library of Medicine, the Cochrane Library, Excerpta Medica dataBASEand the Cumulative Index to Nursing and Allied Health Literature database, and a search strategy was performed by using database-specific subject headings and keywords. We found that available scientific evidence on these topics is scarce, and that the limited number of available studies often have poor methodological quality. Only a few foods show beneficial effects on metabolism and energy expenditure, as the human energy balance is complex and multifactorial. Finally, microbiota may interfere with the intake, use and expenditure of energy in the human body. Conclusive evidence is still lacking, and, at present, it is not possible to identify a food or a diet with a significant impact on human energy expenditure

Spectroscopic Survey of 1.4 GHz and 24 μm Sources in the Spitzer First Look Survey with WIYN Hydra

We present an optical spectroscopic survey of 24 μm and 1.4 GHz sources, detected in the Spitzer extragalactic First Look Survey (FLS), using the multifiber spectrograph, Hydra, on the WIYN telescope. We have obtained spectra for 772 sources, with flux densities above 0.15 mJy in the infrared and 0.09 mJy in the radio. The redshifts measured in this survey are mostly in the range 0 < z < 0.4, with a distribution peaking at z ~ 0.2. Detailed spectral analysis of our sources reveals that the majority are emission-line star-forming galaxies, with star formation rates in the range 0.2-200 M_☉ yr^(-1). The rates estimated from the Hα line fluxes are found to be on average consistent with those derived from the 1.4 GHz luminosities. For these star-forming systems, we find that the 24 μm and 1.4 GHz flux densities follow an infrared-radio correlation, which can be characterized by a value of q_(24) = 0.83, with a 1 σ scatter of 0.31. Our WIYN Hydra database of spectra nicely complements those obtained by the Sloan Digital Sky Survey in the region at lower redshift, as well as the MMT Hectospec survey by Papovich et al. in 2006, and brings the redshift completeness to 70% for sources brighter than 2 mJy at 24 μm. Applying the classical 1/V_(max) method, we derive new 24 μm and 1.4 GHz luminosity functions, using all known redshifts in the FLS. We find evidence for evolution in both the 1.4 GHz and 24 μm luminosity functions in the redshift range 0 < z < 1. The redshift catalog and spectra presented in this paper are available at the Spitzer FLS Web site