Automated Adaptive Optics [IMA]

http://arxiv.org/abs/1709.07103


Large area surveys will dominate the forthcoming decades of astronomy and their success requires characterizing thousands of discoveries through additional observations at higher spatial or spectral resolution, and at complementary cadences or periods. Only the full automation of adaptive optics systems will enable high-acuity, high-sensitivity follow-up observations of several tens of thousands of these objects per year, maximizing on-sky time. Automation will also enable rapid response to target-of-opportunity events within minutes, minimizing the time between discovery and characterization.
In June 2012, we demonstrated the first fully automated operation of an astronomical adaptive optics system by observing 125 objects in succession with the Robo-AO system. Efficiency has increased ever since, with a typical night comprising 200-250 automated observations at the visible diffraction limit. By observing tens of thousands of targets in the largest-ever adaptive-optics surveys, Robo-AO has demonstrated the ability to address the follow-up needs of current and future large astronomical surveys.

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C. Baranec, R. Riddle and N. Law
Fri, 22 Sep 17
3/75

Comments: Preprint of an article submitted for consideration in The WSPC Handbook of Astronomical Instrumentation this http URL

GALARIO: a GPU Accelerated Library for Analysing Radio Interferometer Observations [IMA]

http://arxiv.org/abs/1709.06999


We present GALARIO, a computational library that exploits the power of modern graphical processing units (GPUs) to accelerate the analysis of observations from radio interferometers like ALMA or Jansky VLA. GALARIO speeds up the computation of synthetic visibilities from a generic 2D model image or a radial brightness profile (for axisymmetric sources). On a GPU, GALARIO is 150 faster than standard Python and 10 times faster than serial C++ code on a CPU. Highly modular, easy to use and to adopt in existing code, GALARIO comes as two compiled libraries, one for Nvidia GPUs and one for multicore CPUs, where both have the same functions with identical interfaces. GALARIO comes with Python bindings but can also be directly used in C or C++. The versatility and the speed of GALARIO open new analysis pathways that otherwise would be prohibitively time consuming, e.g. fitting high resolution observations of large number of objects, or entire spectral cubes of molecular gas emission. It is a general tool that can be applied to any field that uses radio interferometer observations. The source code is available online at https://github.com/mtazzari/galario under the open source GNU Lesser General Public License v3.

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M. Tazzari, F. Beaujean and L. Testi
Fri, 22 Sep 17
12/75

Comments: 13 pages, 9 figures. Submitted to MNRAS. Code at this https URL and documentation at this https URL

Observing Compact Stars with AstroSat [IMA]

http://arxiv.org/abs/1709.07152


This article presents a brief description of India’s AstroSat mission which is a powerful space based observatory for compact star research. An account is given of observational constraints and spectral and timing capabilities as realised post-launch. Some preliminary results of observations of the Crab pulsar and an X-ray binary system GX~301-2 are presented to illustrate some of the capabilities of the mission.

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D. Bhattacharya
Fri, 22 Sep 17
16/75

Comments: Has appeared in Journal of Astrophysics and Astronomy special issue on ‘Physics of Neutron Stars and Related Objects’, celebrating the 75th birth-year of G. Srinivasan.”

Sustaining ALMA Science Through 2030 A North American Perspective [IMA]

http://arxiv.org/abs/1709.07044


ALMA will sustain its transformational science through 2030 via an aggressive series of upgrades, for which an overview is provided.

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H. Wootten
Fri, 22 Sep 17
22/75

Comments: 2 pages, submitted to National Radio Science Meeting (NRSM) 4-7 Jan 2017, Boulder Colorado

The Science Case for Simultaneous mm-Wavelength Receivers in Radio Astronomy [IMA]

http://arxiv.org/abs/1709.07167


This review arose from the European Radio Astronomy Technical Forum (ERATec) meeting held in Firenze, October 2015, and aims to highlight the breadth and depth of the high-impact science that will be aided and assisted by the use of simultaneous mm-wavelength receivers. Recent results and opportunities are presented and discussed from the fields of: continuum VLBI (observations of weak sources, astrometry, observations of AGN cores in spectral index and Faraday rotation), spectral line VLBI (observations of evolved stars and massive star-forming regions) and time domain observations of the flux variations arising in the compact jets of X-ray binaries. Our survey brings together a large range of important science applications, which will greatly benefit from simultaneous observing at mm-wavelengths. Such facilities are essential to allow these applications to become more efficient, more sensitive and more scientifically robust. In some cases without simultaneous receivers the science goals are simply unachievable. Similar benefits would exist in many other high frequency astronomical fields of research.

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R. Dodson, M. Rioja, T. Jung, et. al.
Fri, 22 Sep 17
31/75

Comments: accepted New Astronomical Reviews

The PICARD Payload Data Centre [IMA]

http://arxiv.org/abs/1709.06993


PICARD is a scientific space mission dedicated to the study of the solar variability origin. A French micro-satellite will carry an imaging telescope for measuring the solar diameter, limb shape and solar oscillations, and two radiometers for measuring the total solar irradiance and the irradiance in five spectral domains, from ultraviolet to infrared. The mission is planed to be launched in 2009 for a 3-year duration. This article presents the PICARD Payload Data Centre, which role is to collect, process and distribute the PICARD data. The Payload Data Centre is a joint project between laboratories, space agency and industries. The Belgian scientific policy office funds the industrial development and future operations under the European Space Agency program. The development is achieved by the SPACEBEL Company. The Belgian operation centre is in charge of operating the PICARD Payload Data Centre. The French space agency leads the development in partnership with the French scientific research centre, which is responsible for providing all the scientific algorithms. The architecture of the PICARD Payload Data Centre (software and hardware) is presented. The software system is based on a Service Oriented Architecture. The host structure is made up of the basic functions such as data management, task scheduling and system supervision including a graphical interface used by the operator to interact with the system. The other functions are mission-specific: data exchange (acquisition, distribution), data processing (scientific and non-scientific processing) and managing the payload (programming, monitoring). The PICARD Payload Data Centre is planned to be operated for 5 years. All the data will be stored into a specific data centre after this period.

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G. Pradels, T. Guinle, G. Thuillier, et. al.
Fri, 22 Sep 17
36/75

Comments: N/A

Design and construction of the POLAR detector [IMA]

http://arxiv.org/abs/1709.07191


The POLAR detector is a space based Gamma Ray Burst (GRB) polarimeter with a wide field of view, which covers almost half the sky. The instrument uses Compton scattering of gamma rays on a plastic scintillator hodoscope to measure the polarization of the incoming photons. The instrument has been successfully launched on board of the Chinese space laboratory Tiangong~2 on September 15, 2016. The construction of the instrument components is described in this article. Details are provided on problems encountered during the construction phase and their solutions. Initial performance of the instrument in orbit is as expected from ground tests and Monte Carlo simulation.

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N. Produit, T. Bao, T. Batsch, et. al.
Fri, 22 Sep 17
46/75

Comments: N/A