The Implications of Galaxy Formation Models for the TeV Observations of Current Detectors

This paper represents a step toward constraining galaxy formation models via TeV gamm a ray observations. We use semi-analytic models of galaxy formation to predict a spectral distribution for the intergalactic infrared photon field, which in turn yields information about the absorption of TeV gamma rays from extra-galactic sources. By making predictions for integral flux observations at >200 GeV for several known EGRE T sources, we directly compare our models with current observational upper limits obtained by Whipple. In addition, our predictions may offer a guide to the observing programs for the current population of TeV gamma ray observatories.Comment: 6 pages, 11 figures, to appear in the proceedings of the 6th TeV Workshop at Snowbird, U

Reciprocal and non-reciprocal recombination between closely linked markers

Reciprocal and non-reciprocal recombination between closely linked marker

Electrodeposition And Analysis Of Tin Selenide Films

Sn1±xSe films have been electrodeposited from aqueous solutions containing SnCl2 and ionically dissolved SeO2 or H2SeO3 and DMF solutions containing SnCl2 and molecularly dissolved selenium powder. The as-deposited films ranged from amorphous to polycrystalline and exhibited indirect or nondirect bandgaps from 0.85 to 0.95 eV. There was little difference between the appearance or material data of the films grown by the two techniques. Direct reaction between Sn++ and H2SeO3 or HSeO3_ in the aqueous solutions yielded a Se/SnxSe suspension/precipitate. Although this does not seem to have any serious effect on the deposition process, it does produce a decrease in the concentration and possibly a change in the composition of the ions in solution, as well as preventing in situ observation of the deposit and making the cleaning of the apparatus more difficult. Annealing slightly increased the Se/Sn ratio of microanalyzed layers near the substrate-deposit interface, and erased all x-ray diffraction structure. The bandgaps of the annealed films were shifted from approximately 0.9 eV to approximately 1.30 eV, consistent with the increased Se/Sn ratio. The films exhibited weak cathodic photocurents during deposition and photoconductance (ΔG/G⋍0.05) after deposition. The conductivity of Sample D (Sn0.91Se) was estimated to be on the order of 10 -4(Ω-cm)-1. Conductance-temperature plots indicated activation energies between 0.44 and 0.51 eV, probably indicative of deep acceptor levels and consistent with the p-type thermal voltage, millisecond photoconductance decay times, and the optical bandgaps. © 1986, The Electrochemical Society, Inc. All rights reserved

EROs found behind lensing clusters: II.Empirical properties, classification, and SED modelling based on multi-wavelength observations

We study the properties and nature of extremely red galaxies (ERO, R-K>5.6) found behind two lensing clusters and compare them with other known galaxy populations. New HST/ACS observations, Spitzer IRAC and MIPS, and Chandra/ACIS observations of the two lensing clusters Abell 1835 and AC114 contemplate our earlier optical and near-IR observations and have been used to study extremely red objects (EROs) in these deep fields. We have found 6 and 9 EROs in Abell 1835 and AC114. Several (7) of these objects are undetected up to the I and/or z band, and are hence ``optical'' drop-out sources. The photometric redshifts of most of our sources (80%) are z~0.7-1.5. According to simple colour-colour diagrams the majority of our objects would be classified as hosting old stellar populations. However, there are clear signs of dusty starbursts for several among them. These objects correspond to the most extreme ones in R-K colour. We estimate a surface density of (0.97+-0.31) arcmin-2 for EROs with (R-K>5.6) at K<20.5. Among our 15 EROs 6 (40 %) also classify as distant red galaxies (DRGs). 11 of 13 EROs with available IRAC photometry also fulfil the selection criteria for IRAC selected EROs (IEROs) of Yan et al. (2004). SED modelling shows that ~ 36 % of the IEROs in our sample are luminous or ultra-luminous infrared galaxies ((U)LIRG). Some very red DRGs are found to be very dusty starbursts, even (U)LIRGs, as also supported by their mid-IR photometry. No indication for AGNs is found, although faint activity cannot be excluded for all objects. From mid-IR and X-ray data 5 objects are clearly classified as starbursts. The derived properties are quite similar to those of DRGs and IEROs, except for 5 extreme objects in terms of colours, for which a very high extinction (Av>3) is found.Comment: 20 pages, 10 figures, accepted for publication in A&

ALMA detection of [CII] 158 micron emission from a strongly lensed z=2 star-forming galaxy

Our objectives are to determine the properties of the interstellar medium (ISM) and of star-formation in typical star-forming galaxies at high redshift. Following up on our previous multi-wavelength observations with HST, Spitzer, Herschel, and the Plateau de Bure Interferometer (PdBI), we have studied a strongly lensed z=2.013 galaxy, the arc behind the galaxy cluster MACS J0451+0006, with ALMA to measure the [CII] 158 micron emission line, one of the main coolants of the ISM. [CII] emission from the southern part of this galaxy is detected at 10 $\sigma$. Taking into account strong gravitational lensing, which provides a magnification of $\mu=49$, the intrinsic lensing-corrected [CII]158 micron luminosity is $L(CII)=1.2 \times 10^8 L_\odot$. The observed ratio of [CII]-to-IR emission, $L(CII)/L(FIR) \approx (1.2-2.4) \times 10^{-3}$, is found to be similar to that in nearby galaxies. The same also holds for the observed ratio $L(CII)/L(CO)=2.3 \times 10^3$, which is comparable to that of star-forming galaxies and active galaxy nuclei (AGN) at low redshift. We utilize strong gravitational lensing to extend diagnostic studies of the cold ISM to an order of magnitude lower luminosity ($L(IR) \sim (1.1-1.3) \times 10^{11} L_\odot$) and SFR than previous work at high redshift. While larger samples are needed, our results provide evidence that the cold ISM of typical high redshift galaxies has physical characteristics similar to normal star forming galaxies in the local Universe.Comment: 5 pages, 4 figures. Accepted for publication in Astronomy & Astrophysics, Letter

Technical design

To convert Bergenmeersen from a flood control area (FCA) to a flood control area with controlled reduced tide (FCA-CRT), the existing dykes were modified and a new inlet and outlet construction was built. This chapter outlines the hydraulic and geotechnical design. This encompasses raising the existing ring dyke around the area, the new stability calculations and the modified dyke revetment along the water and land side. The inlet and outlet structure is also described. The hydraulic boundary conditions are extremely important to the design