125 research outputs found
WEIRD: Wide-orbit Exoplanet search with InfraRed Direct imaging
We report results from the Wide-orbit Exoplanet search with InfraRed Direct
imaging (WEIRD), a survey designed to search for Jupiter-like companions on
very wide orbits (1000 to 5000 AU) around young stars (120 Myr) that are
known members of moving groups in the solar neighborhood (70 pc). Sharing
the same age, distance, and metallicity as their host while being on large
enough orbits to be studied as "isolated" objects make such companions prime
targets for spectroscopic observations and valuable benchmark objects for
exoplanet atmosphere models. The search strategy is based on deep imaging in
multiple bands across the near-infrared domain. For all 177 objects of our
sample, , , [3.6] and [4.5] images were obtained with
CFHT/MegaCam, GEMINI/GMOS, CFHT/WIRCam, GEMINI/Flamingos-2, and /IRAC.
Using this set of 4 images per target, we searched for sources with red
and colors, typically reaching good completeness
down to 2Mjup companions, while going down to 1Mjup for some targets, at
separations of AU. The search yielded 4 candidate companions with
the expected colors, but they were all rejected through follow-up proper motion
observations. Our results constrain the occurrence of 1-13 Mjup planetary-mass
companions on orbits with a semi-major axis between 1000 and 5000 AU at less
than 0.03, with a 95\% confidence level.Comment: 55 pages, 16 figures, accepted to A
Next generation portal for federated testbeds MySlice v2: from prototype to production
A number of projects in computer science around the world have contributed to
build federated experimental facilities providing access to a large set of
distributed compute, storage and network resources for the research community.
Several tools have been developed to provide users an easy access to the
federated testbeds. This paper presents the architecture of the new version of
the MySlice web portal, that has evolved from a prototype to a production ready
software
Exploiting spatial sparsity for multi-wavelength imaging in optical interferometry
Optical interferometers provide multiple wavelength measurements. In order to
fully exploit the spectral and spatial resolution of these instruments, new
algorithms for image reconstruction have to be developed. Early attempts to
deal with multi-chromatic interferometric data have consisted in recovering a
gray image of the object or independent monochromatic images in some spectral
bandwidths. The main challenge is now to recover the full 3-D (spatio-spectral)
brightness distribution of the astronomical target given all the available
data. We describe a new approach to implement multi-wavelength image
reconstruction in the case where the observed scene is a collection of
point-like sources. We show the gain in image quality (both spatially and
spectrally) achieved by globally taking into account all the data instead of
dealing with independent spectral slices. This is achieved thanks to a
regularization which favors spatial sparsity and spectral grouping of the
sources. Since the objective function is not differentiable, we had to develop
a specialized optimization algorithm which also accounts for non-negativity of
the brightness distribution.Comment: This version has been accepted for publication in J. Opt. Soc. Am.
Next generation portal for federated testbeds MySlice v2: from prototype to production
International audienceA number of projects in computer science around the world have contributed to build federated experimental facilities providing access to a large set of distributed compute, storage and network resources for the research community. Several tools have been developed to provide users an easy access to the federated testbeds. This paper presents the architecture of the new version of the MySlice web portal, that has evolved from a prototype to a production ready software
OneLab: On-demand deployment of IoT over IPv6: Infrastructure as a service for IEEE INFOCOM community
International audienceThis demonstration will explain how an experimenter can easily deploy an end-to-end IoT and Cloud infrastructure using the OneLab federation of testbeds. It will highlight the importance of using IPv6 in this context
OneLab Tutorial: A Single Portal to Heterogeneous Testbeds
International audienceLarge-scale experimentation in varying types of environments is difficult to achieve, and until recently, experimenters have had to either construct their own platforms or rely on simulation, emulation, or analysis to gain results. However, these methods largely do not provide adequate or verified results. There lacked a viable model for the federation of large-scale testbeds that reconciled the challenges posed by how to provide a single entry point to access heterogeneous and distributed resources, and how to federate these resources that are under the control of multiple authorities. Efforts such as the FIRE initiative in Europe and GENI in the United States have worked to develop such a model, and the OneLab experimental facility, which came online in 2014, realizes this model, making a set of world-class testbeds freely available to researchers through a unique credential for each user and a common set of tools. OneLab provides a large-scale facility for rapid and remote testing that produces exhaustive results, at no charge to the experimenter. We allow users to deploy innovative experiments across our federated platforms that include the embedded object testbeds of FIT IoT-Lab, the cognitive radio testbed of FIT CorteXlab, the wireless testbeds of NITOS-Lab, and the internet overlay testbeds of PlanetLab Europe (PLE), which together provide thousands of nodes for experimentation. The OneLab portal allows single-entry point access to these platforms, and provides users with unique credentials. This is made possible through the adoption of Slice-based Federation Architecture (SFA), an API for authentication and authorization that was conceptualized by the GENI initiative in the US, where each authority authenticates users and authorizes access to the resources; and MySlice, the portal technology that we have developed to federate heterogeneous resources
Federation of Internet experimentation facilities: architecture and implementation
International audienceRealistic experimentation facilities are indispensable to accelerate the design of novel Future Internet systems. As many of these ground-breaking new applications and services cover multiple innovation areas, the need for these solutions to be tested on cross-domain facilities with both novel infrastructure technologies and newly emerging service platforms is rising. The Fed4FIRE project therefore aims at federatingotherwise isolated experimentation facilities in order to foster synergies between research communities. Currently the federation includes over 15 facilities from the Future Internet Research and Experiment (FIRE) initiative, covering wired, wireless and sensor networks, SDN and OpenFlow, cloud computing, smart city services,etc.This paper presents the architecture and implementation details of the federation, based on an extensive set of requirements coming from infrastructure owners, service providers and support communitie
WEIRD: Wide-orbit Exoplanet Search with InfraRed Direct Imaging
We report results from the Wide-orbit Exoplanet search with InfraRed Direct imaging, or WEIRD, a survey designed to search for Jupiter-like companions on very wide orbits (1000–5000 au) around young stars (<120 Myr) that are known members of moving groups in the solar neighborhood (<70 pc). Companions that share the same age, distance, and metallicity as their host while being on large enough orbits to be studied as "isolated" objects make prime targets for spectroscopic observations, and they are valuable benchmark objects for exoplanet atmosphere models. The search strategy is based on deep imaging in multiple bands across the near-infrared domain. For all 177 objects of our sample, z_(ab)', J, [3.6], and [4.5] images were obtained with CFHT/MegaCam, GEMINI/GMOS, CFHT/WIRCam, GEMINI/Flamingos-2, and Spitzer/IRAC. Using this set of four images per target, we searched for sources with red z_(ab)' and [3.6]–[4.5] colors, typically reaching good completeness down to 2 M_(Jup) companions, while going down to 1 M_(Jup) for some targets, at separations of 1000–5000 au. The search yielded four candidate companions with the expected colors, but they were all rejected through follow-up proper motion observations. Our results constrain the occurrence of 1–13 M_(Jup) planetary-mass companions on orbits with a semimajor axis between 1000 and 5000 au at less than 0.03, with a 95% confidence level
Control plane extension - Status of the SFA deployment
FP7 OpenLab project deliverable D1.2This document describes the progress made within Work Package 1 "Control Plane Extensions" over the second year of the OpenLab project
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