Using Java for distributed computing in the Gaia satellite data processing

In recent years Java has matured to a stable easy-to-use language with the flexibility of an interpreter (for reflection etc.) but the performance and type checking of a compiled language. When we started using Java for astronomical applications around 1999 they were the first of their kind in astronomy. Now a great deal of astronomy software is written in Java as are many business applications. We discuss the current environment and trends concerning the language and present an actual example of scientific use of Java for high-performance distributed computing: ESA's mission Gaia. The Gaia scanning satellite will perform a galactic census of about 1000 million objects in our galaxy. The Gaia community has chosen to write its processing software in Java. We explore the manifold reasons for choosing Java for this large science collaboration. Gaia processing is numerically complex but highly distributable, some parts being embarrassingly parallel. We describe the Gaia processing architecture and its realisation in Java. We delve into the astrometric solution which is the most advanced and most complex part of the processing. The Gaia simulator is also written in Java and is the most mature code in the system. This has been successfully running since about 2005 on the supercomputer "Marenostrum" in Barcelona. We relate experiences of using Java on a large shared machine. Finally we discuss Java, including some of its problems, for scientific computing.Comment: Experimental Astronomy, August 201

The North American and Pelican Nebulae I. IRAC Observations

We present a 9 deg^2 map of the North American and Pelican Nebulae regions obtained in all four IRAC channels with the Spitzer Space Telescope. The resulting photometry is merged with that at JHKs from 2MASS and a more spatially limited $BVI$ survey from previous ground-based work. We use a mixture of color- color diagrams to select a minimally contaminated set of more than 1600 objects that we claim are young stellar objects (YSOs) associated with the star forming region. Because our selection technique uses IR excess as a requirement, our sample is strongly biased against inclusion of Class III YSOs. The distribution of IRAC spectral slopes for our YSOs indicates that most of these objects are Class II, with a peak towards steeper spectral slopes but a substantial contribution from a tail of flat spectrum and Class I type objects. By studying the small fraction of the sample that is optically visible, we infer a typical age of a few Myr for the low mass population. The young stars are clustered, with about a third of them located in eight clusters that are located within or near the LDN 935 dark cloud. Half of the YSOs are located in regions with surface densities higher than 1000 YSOs / deg^2. The Class I objects are more clustered than the Class II stars.Comment: 16 pages, 12 figures, ApJ In pres

ESA Science Programme Missions: Contributions and Exploitation -- Herschel Observing Time Proposals

After an introduction to the ESA Herschel Space Observatory including a mission overview, science objectives, results and productivity we examine the process and outcomes of the announcements of observing opportunities (AOs). For Herschel, in common with other ESA observatories, there were no rules, quotas, or guidelines for the allocation of observing time based on the geographical location of the lead proposer's institute, gender, or seniority (academic age); scientific excellence was the most important single factor. We investigate whether and how success rates vary with these (other) parameters. Due to the relatively short operational duration of Herschel -- compared to XMM-Newton and INTEGRAL -- in addition to the pre-launch AO in 2007 there was just two further AOs, in 2010 and 2011. In order to extend the time-frame we compare results with those from the ESA Infrared Space Observatory (ISO) whose time allocation took place approximately 15 years earlier.Comment: To be submitted to Springer for publication in the ISSI Scientific Reports serie

Cosmos, culture and landscape : documenting, learning and sharing Aboriginal astronomical knowledge in contemporary society

Contemporary Australian Aboriginal astronomical knowledge, its documentation, sharing and communication is investigated, primarily from three Western Australian locations (1) Murchison region (associated with Murchison Radio-astronomy Observatory), (2) East Kimberley (Wolfe Creek Meteorite Crater) and (3) the South West of Western Australia. Astronomical knowledge is examined via three surveys and in-depth interviews with 27 participants. Digital imaging (360° & timelapse) is applied to create new and original Aboriginal astronomy resources (virtual tour and exhibition videos)

SciTech News Volume 71, No. 3 (2017)

Columns and Reports From the Editor.........................3 Division News Science-Technology Division....5 Chemistry Division....................8 Conference Report, Marion E, Sparks Professional Development Award Recipient..9 Engineering Division................10 Engineering Division Award, Winners Reflect on their Conference Experience..15 Aerospace Section of the Engineering Division .....18 Architecture, Building Engineering, Construction, and Design Section of the Engineering Division................20 Reviews Sci-Tech Book News Reviews...22 Advertisements IEEE..........................................