A novel adenovirus vector for easy cloning in the E3 region downstream of the CMV promoter

The construction of expression vectors derived from the human adenovirus type 5 (Ad5), usually based on homologous recombination, is time consuming as a shuttle plasmid has to be selected before recombination with the viral genome. Here, we describe a method allowing direct cloning of a transgene in the E3 region of the Ad5 genome already containing the immediate early CMV promoter upstream of three unique restriction sites. This allowed the construction of recombinant adenoviral genomes in just one step, reducing considerably the time of selection and, of course, production of the corresponding vectors. Using this vector, we produced recombinant adenoviruses, each giving high-level expression of the transgene in the transduced cells

Impacts of The Radiation Environment At L2 On Bolometers Onboard The Herschel Space Observatory

We present the effects of cosmic rays on the detectors onboard the Herschel satellite. We describe in particular the glitches observed on the two types of cryogenic far- infrared bolometer inside the two instruments PACS and SPIRE. The glitch rates are also reported since the launch together with the SREM radiation monitors aboard Herschel and Planck spacecrafts. Both have been injected around the Lagrangian point L2 on May 2009. This allows probing the radiation environment around this orbit. The impacts on the observation are finally summarized.Comment: 8 pages, 13 figures, 2 images, Author Keywords: Bolometers, Infrared detectors, cryogenics, radiation effects, submillimeter wave technology IEEE Terms: Bolometers, Detectors, Instruments, Picture archiving and communication systems, Protons, Silicon, Space vehicles; Radiation and Its Effects on Components and Systems (RADECS), 2011 12th European Conference. Conference location: Sevilla. Date of Conference: 19-23 Sept. 2011. Session H: Radiation Environment: Space, Atmospheric and Terrestrial (PH2

CEA Bolometer Arrays: the First Year in Space

The CEA/LETI and CEA/SAp started the development of far-infrared filled bolometer arrays for space applications over a decade ago. The unique design of these detectors makes possible the assembling of large focal planes comprising thousands of bolometers running at 300 mK with very low power dissipation. Ten arrays of 16x16 pixels were thoroughly tested on the ground, and integrated in the Herschel/PACS instrument before launch in May 2009. These detectors have been successfully commissioned and are now operating in their nominal environment at the second Lagrangian point of the Earth-Sun system. In this paper we briefly explain the functioning of CEA bolometer arrays, and we present the properties of the detectors focusing on their noise characteristics, the effect of cosmic rays on the signal, the repeatability of the measurements, and the stability of the system

Influence of Projection in Cluster Cosmology Studies

Projection tends to skew the mass-observable relation of galaxy clusters by creating a small fraction of severely blended systems, those for which the measured observable property of a cluster is strongly boosted relative to the value of its primary host halo. We examine the bias in cosmological parameter estimates caused by incorrectly assuming a Gaussian (projection-free) mass-observable relation when the true relation is non-Gaussian due to projection. We introduce a mixture model for projection and explore Fisher forecasts for a survey of 5000 sq. deg. to z=1.1 and an equivalent mass threshold of 10^13.7 h^-1 solar masses. Using a blended fraction motivated by optical cluster finding applied to the Millennium Simulation and applying Planck and otherwise weak priors, we find that the biases in Omega_DE and w are significant, being factors of 2.8 and 2.4, respectively, times previous forecast uncertainties. Incorporating eight new degrees of freedom to describe cluster selection with projection increases the forecast uncertainty in Omega_DE and w by similar factors. Knowledge of these additional parameters at the 5% level limits degradation in dark energy constraints to <10% relative to projection-free forecasts. We discuss strategies for using simulations and complementary observations to characterize the fraction of blended clusters and their mass selection properties.Comment: 11 pages, 4 figures to be submitted to phys. rev.

Ringing effects reduction by improved deconvolution algorithm Application to A370 CFHT image of gravitational arcs

We develop a self-consistent automatic procedure to restore informations from astronomical observations. It relies on both a new deconvolution algorithm called LBCA (Lower Bound Constraint Algorithm) and the use of the Wiener filter. In order to explore its scientific potential for strong and weak gravitational lensing, we process a CFHT image of the galaxies cluster Abell 370 which exhibits spectacular strong gravitational lensing effects. A high quality restoration is here of particular interest to map the dark matter within the cluster. We show that the LBCA turns out specially efficient to reduce ringing effects introduced by classical deconvolution algorithms in images with a high background. The method allows us to make a blind detection of the radial arc and to recover morphological properties similar to thoseobserved from HST data. We also show that the Wiener filter is suitable to stop the iterative process before noise amplification, using only the unrestored data.Comment: A&A in press 9 pages 9 figure

Finding Galaxy Clusters using Voronoi Tessellations

We present an objective and automated procedure for detecting clusters of galaxies in imaging galaxy surveys. Our Voronoi Galaxy Cluster Finder (VGCF) uses galaxy positions and magnitudes to find clusters and determine their main features: size, richness and contrast above the background. The VGCF uses the Voronoi tessellation to evaluate the local density and to identify clusters as significative density fluctuations above the background. The significance threshold needs to be set by the user, but experimenting with different choices is very easy since it does not require a whole new run of the algorithm. The VGCF is non-parametric and does not smooth the data. As a consequence, clusters are identified irrispective of their shape and their identification is only slightly affected by border effects and by holes in the galaxy distribution on the sky. The algorithm is fast, and automatically assigns members to structures.Comment: 11 pages, 11 figures. It uses aa.cls (included). Accepted by A&

Mid-Infrared Emission Features in the ISM: Feature-to-Feature Flux Ratios

Using a limited, but representative sample of sources in the ISM of our Galaxy with published spectra from the Infrared Space Observatory, we analyze flux ratios between the major mid-IR emission features (EFs) centered around 6.2, 7.7, 8.6 and 11.3 microns, respectively. In a flux ratio-to-flux ratio plot of EF(6.2)/EF(7.7) as a function of EF(11.3)/EF(7.7), the sample sources form roughly a $\Lambda$-shaped locus which appear to trace, on an overall basis, the hardness of a local heating radiation field. But some driving parameters other than the radiation field may also be required for a full interpretation of this trend. On the other hand, the flux ratio of EF(8.6)/EF(7.7) shows little variation over the sample sources, except for two HII regions which have much higher values for this ratio due to an ``EF(8.6\um) anomaly,'' a phenomenon clearly associated with environments of an intense far-UV radiation field. If further confirmed on a larger database, these trends should provide crucial information on how the EF carriers collectively respond to a changing environment.Comment: 16 pages, 1 figure, 1 table; accepted for publication in ApJ Letter

DUNE: The Dark Universe Explorer

Understanding the nature of Dark Matter and Dark Energy is one of the most pressing issues in cosmology and fundamental physics. The purpose of the DUNE (Dark UNiverse Explorer) mission is to study these two cosmological components with high precision, using a space-based weak lensing survey as its primary science driver. Weak lensing provides a measure of the distribution of dark matter in the universe and of the impact of dark energy on the growth of structures. DUNE will also include a complementary supernovae survey to measure the expansion history of the universe, thus giving independent additional constraints on dark energy. The baseline concept consists of a 1.2m telescope with a 0.5 square degree optical CCD camera. It is designed to be fast with reduced risks and costs, and to take advantage of the synergy between ground-based and space observations. Stringent requirements for weak lensing systematics were shown to be achievable with the baseline concept. This will allow DUNE to place strong constraints on cosmological parameters, including the equation of state parameter of the dark energy and its evolution from redshift 0 to 1. DUNE is the subject of an ongoing study led by the French Space Agency (CNES), and is being proposed for ESA's Cosmic Vision programme

An Efficient Approach to Obtaining Large Numbers of Distant Supernova Host Galaxy Redshifts

We use the wide-field capabilities of the 2dF fibre positioner and the AAOmega spectrograph on the Anglo-Australian Telescope (AAT) to obtain redshifts of galaxies that hosted supernovae during the first three years of the Supernova Legacy Survey (SNLS). With exposure times ranging from 10 to 60 ksec per galaxy, we were able to obtain redshifts for 400 host galaxies in two SNLS fields, thereby substantially increasing the total number of SNLS supernovae with host galaxy redshifts. The median redshift of the galaxies in our sample that hosted photometrically classified Type Ia supernovae (SNe Ia) is 0.77, which is 25% higher than the median redshift of spectroscopically confirmed SNe Ia in the three-year sample of the SNLS. Our results demonstrate that one can use wide-field fibre-fed multi-object spectrographs on 4m telescopes to efficiently obtain redshifts for large numbers of supernova host galaxies over the large areas of sky that will be covered by future high-redshift supernova surveys, such as the Dark Energy Survey.Comment: 22 pages, 4 figures, accepted for publication in PAS