Extreme multiplex spectroscopy at wide-field 4-m telescopes

We describe the design and science case for a spectrograph for the prime focus of classical 4-m wide-field telescopes that can deliver at least 4000 MOS slits over a 1 degree field. This extreme multiplex capability means that 25000 galaxy redshifts can be measured in a single night, opening up the possibilities for large galaxy redshift surveys out to z~0.7 and beyond for the purpose of measuring the Baryon Acoustic Oscillation (BAO) scale and for many other science goals. The design features four cloned spectrographs and exploits the exclusive possibility of tiling the focal plane of wide-field 4-m telescopes with CCDs for multi-object spectroscopic purposes. In ~200 night projects, such spectrographs have the potential to make galaxy redshift surveys of ~6 million galaxies over a wide redshift range and thus may provide a low-cost alternative to other survey routes such as WFMOS and SKA. Two of these extreme multiplex spectrographs are currently being designed for the AAT (NG1dF) and Calar Alto (XMS) 4-m class telescopes. NG2dF, a larger version for the AAT 2 degree field, would have 12 clones and at least 12000 slits. The clones use a transparent design including a grism in which all optics are smaller than the clone square subfield so that the clones can be tightly packed with little gaps between the contiguous fields. Only low cost glasses are used; the variations in chromatic aberrations between bands are compensated by changing one or two of the lenses adjacent to the grism. The total weight and length is smaller with a few clones than a unique spectrograph which makes it feasible to place the spectrograph at the prime focus.Comment: 8 pages, 4 figures, to appear in proceedings of Astronomical Telescopes and Instrumentation, SPIE conference, Marseille, 23-28 June, 200

Content

DAFTAR ISIImplementasi Content-Based Retrieval Pada Perpustakaan Digital Berbasis Open Source Menggunakan Apache Lucene David Pages: 1-13Perancangan Sistem Kendali Otomatik Proses Pengolahan Limbah Cair Tahu Berbasis Mikrokontroler AT89S52Barita Bram Ardiwinata Putra Pages: 14-25Analisis Penerapan Arsitektur Wireless LAN Menggunakan Top Down Approach pada PT. Telkom Pontianak Sandy Kosasi Pages: 26-42Sistem Intelijen Bisnis Global untuk Perencanaan e-commerce Budi Susilo Pages: 43-52Understanding e-Business & e-Commerce and Their Relation to the Conceptual framework of e-Marketing: Case Study Alexander Harsono Pages: 53-68Analisis dan Perancangan Aplikasi Persediaan pada CV. Fajar Khatulistiwa Motor PontianakSusanti Margaretha Kuway Pages: 69-79Analisis Penerapan Aplikasi Sistem Akuntansi Persediaan Menggunakan Technology Acceptance Model (TAM) pada Distrik Navigasi Kelas III PontianakSlamet Sugiarto, Rusmanto Lianto Pages: 80-94Implementasi Web Services Sistem Integrasi Data Menggunakan Teknik Replikasi Data Pada Inventarisasi Bangunan Pemerintah Ilhamsyah Pages: 95-10

Optical Tests of a 3.7-m diameter Liquid Mirror: Behavior under External Perturbations

We have built and tested a 3.7-m diameter liquid mirror that rotates on a ball bearing. We have carried out extensive optical tests. We find that although the ball bearing has a poor quality, the quality of the mirror, with mercury layers 1-mm thick, is surprisingly good. Taken at face values the instantaneous Strehl ratios indicate a mirror, that is not quite diffraction limited but usable for astronomical applications. However, the large coning error of the bearing (1.5 arcseconds P-V) induces an excessive wobble, considerably worsening the time averaged PSF. The most interesting result of the interferometry is that we do not see any evidence of the strong astigmatism that may have been expected from Coriolis forces.Comment: PDF format, 34 pages, 12 figures, (some figures reduced, full size figures in Applied Optics, Vol. 39, No 36, 5651

Human fibroblast interferon RNA transcripts of different sizes in poly(I).poly(C) induced cells

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Stellar populations -- the next ten years

The study of stellar populations is a discipline that is highly dependent on both imaging and spectroscopy. I discuss techniques in different regimes of resolving power: broadband imaging (R~4), intermediate band imaging (R~16, 64), narrowband spectral imaging (R~256, 1024, 4096). In recent years, we have seen major advances in broadband all-sky surveys that are set to continue across optical and IR bands, with the added benefit of the time domain, higher sensitivity, and improved photometric accuracy. Tunable filters and integral field spectrographs are poised to make further inroads into intermediate and narrowband imaging studies of stellar populations. Further advances will come from AO-assisted imaging and imaging spectroscopy, although photometric accuracy will be challenging. Integral field spectroscopy will continue to have a major impact on future stellar population studies, extending into the near infrared once the OH suppression problem is finally resolved. A sky rendered dark will allow a host of new ideas to be explored, and old ideas to be revisited.Comment: Invited review, IAUS 241, "Stellar Populations as Building Blocks of Galaxies," eds. Vazdekis, Peletier. 12 pages, 1 table. (The sideways table should print ok; there are 10 columns.

Design and construction of the IMACS-IFU, a 2000-element integral field unit

The IMACS-IFU is an Integral Field Unit built for the IMACS spectrograph at the Magellan-I-Telescope at Las Campanas Observatory. It consists of two rectangular fields of 5 by 7 arcseconds, separated by roughly one arcminute. With a total number of 2000 spatial elements it is the second largest fiber-lenslet based IFU worldwide, working in a wavelength range between 400 and 900 nm. Due to the equally sized fields classical background subtraction, beam switching and shuffling are possible observation techniques. One particular design challenge was the single, half a metre long curved slit in combination with a non telecentric output. Besides the construction some preliminary results are described.Comment: 10 pages, 7 figures, 1 table. Proceedings for SPIE poster 5492-175 of SPIE Symposium "Astronomical Telescopes and Instrumentation", June 2004, Glasgo

Photonic lantern behaviour and implications for instrument design

Photonic lanterns are an important enabling technology for astrophotonics with a wide range of potential applications including fibre Bragg grating OH suppression, integrated photonic spectrographs and fibre scramblers for high resolution spectroscopy. The behaviour of photonic lanterns differs in several important respects from the conventional fibre systems more frequently used in astronomical instruments and a detailed understanding of this behaviour is required in order to make the most effective use of this promising technology. To this end we have undertaken a laboratory study of photonic lanterns with the aim of developing an empirical model for the mapping from input to output illumination distributions. We have measured overall transmission and near field output light distributions as a function of input angle of incidence for photonic lanterns with between 19 and 61 cores. We present the results of this work, highlight the key differences between photonic lanterns and conventional fibres, and illustrate the implications for instrument design via a case study, the design of the PRAXIS spectrograph. The empirical photonic lantern model was incorporated into an end-to-end PRAXIS performance model which was used to optimise the design parameters of the instrument. We describe the methods used and the resulting conclusions. The details of photonic lantern behaviour proved particularly important in selecting the optimum on sky field of view per fibre and in modelling of the instrument thermal background.Comment: 18 pages, 14 figures, presented at SPIE Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation 2014, to be published in Proc. SPIE 915

Communicative Content and Legal Content

This essay investigates a familiar set of questions about the relationship between legal texts (e.g., constitutions, statutes, opinions, orders, and contracts) and the content of the law (e.g., norms, rules, standards, doctrines, and mandates). Is the original meaning of the constitutional text binding on the Supreme Court when it develops doctrines of constitutional law? Should statutes be given their plain meaning or should judges devise statutory constructions that depart from the text to serve a purpose? What role should default rules play in the interpretation and construction of contracts? This essay makes two moves that can help lawyers and legal theorists answer these questions. First, there is a fundamental conceptual distinction between communicative content (the linguistic meaning communicated by a legal text in context) and legal content (the doctrines of the legal rules associated with a text). Second, the relationship between communicative content and legal content varies with context; different kinds of legal texts produce different relationships between linguistic meaning and legal rules

Content Individuation and Evolutionary Content Emergence

This short paper addresses two connected issues which were brought to some focused light by Searle’s comments on my contributed article to the anthology Searle’s philosophy and Chinese Philosophy: Constructive Engagement. The first issue concerns the claim that animals cannot have observer-independent intentional content of the same type as that of human beings. The second is my denial that mental content can be merely caused in specific brain states, given its holistic and normative character. I defend my position on the second issue by distinguishing content individuation from content realization while I elaborate my relatively more sophisticated argument for the first claim by clarifying two related senses or levels of ‘content’ and ‘self’, respectively associated with certain quasi-rational capacities from a third-person perspective and the subjective holistic consciousness from a first-person perspective with the explicit social-discursive dimension. Searle’s Connection Principle is briefly drawn on in this context, with an eye to showing its potential significance when it is extended into the evolutionary settings. In short, it is the full-blown rationality of human holistic discursive practice that ultimately grounds the content talk, which then becomes meaningfully ascribable to certain natural forms of animal existence