Download or read book Wide Field Spectroscopy written by E. Kontizas and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: E. KONTIZAS Astronomical Institute National Observatory of Athens P. O. Box 20048 Athens GR-1181O GREECE The international conference on "Wide-Field Spectroscopy" and its sub ject matter were agreed during the general assembly of the International Astronomical Union (IAU) in August 1994 by the Working Group of Com mision 9 "Wi de-Field Imaging". This meeting gave an opportunity to world experts on this subject to gather in Athens, in order to discuss the cur rent exploitation and the impending opportunities that exist in the area of multi-object spectroscopy, with particular emphasis on: 1. Astronomical instruments, data acquisition, processing and analysis techniques. 2. Astrophysical problems best tackled through wide-field, multi-object spectroscopy. The new fibre optic technology offers an important tool for the advancement of basic research and the development of industrial applications. Astronom ical spectroscopy is a field of astronomy which has contributed much to the advancement of fundamental physics. The spectra of hot stars have been used to determine the well-known Balmer formula for the wavelength of hydrogen lines, in the late 19th century. Since then, spectroscopy has made enormous progress in stellar atmosphere studies, in kinematics, and in the detection of high redshifts in the Universe. The traditional techniques of obtaining wide-field spectroscopic data are based on slitless spectroscopy (objective prism). Several observations, world wide, make use ofthese tech niques in order to obtain information on the spectral properties of objects in large areas of the sky.

Download or read book Wide Field Spectroscopy And The Distant Universe Proceedings Of The 35th Herstmonceux Conference written by S Maddox and published by World Scientific. This book was released on 1995-05-31 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Galaxies represent the most readily visible fabric of the cosmos. Their morphological types, luminosities and environmental surroundings contain valuable clues as to their origin and evolution. Locally, a strong correlation is seen between galaxy morphology and environmental location; this may have been molded at surprisingly modest redshifts. Spectroscopic and photometric studies of deep fields also suggest remarkably recent changes in the galaxy population. The associated growth of structure during the same interval can be tracked via X-ray studies of distant clusters of galaxies.Very recently, impressive observational facilities have been completed, each of which has extended the astronomers' dataset to look-back times where such evolutionary effects can be studied.This volume discusses surveys which share a common theme — the need for a large number of ground-based spectra. It focuses on the various approaches via a single theme concerned with the evolution of galaxies and their distribution. In the near future, impressive new observational facilities will be able to generate large statistical spectroscopic surveys, and the aim of this volume is to assess the scientific impact that ongoing and future spectroscopic surveys can make. Emphasis is placed on the role of non-optical and satellite facilities and the co-ordination of international efforts.

Download or read book Wide Field Spectroscopy and the Distant Universe written by Steve J. Maddox and published by World Scientific. This book was released on 1995 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Two Dimensional Wide Field Spectroscopy of Nearby Spiral Galaxies written by Fernando Fabián Rosales Ortega and published by LAP Lambert Academic Publishing. This book was released on 2010-08 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: The emergence of a new generation of instrumentation in astrophysics, which provide spatially-resolved spectra over a large 2-dimensional (2D) field of view, is opening up a new frontier in the development of surveys based on samples of hundreds of spectra in a 2D context. The observational techniques introduced in this book represent the first attempt to obtain continuous coverage spectra of the disk of a galaxy in the nearby Universe, by the application of the Integral Field Spectroscopy (IFS) technique. A self-consistent methodology is defined in terms of observation, data reduction and analysis techniques for wide-field IFS surveys. This novel approach is used to analyse the properties of the ionized gas and to perform a detailed 2D study of the emission line spectra in a sample of nearby spiral galaxies. This work should be particularly useful to astronomy graduate students and advance researches with interests in the study of the interstellar medium, chemical abundances in galaxies and observational spectroscopic techniques.

Download or read book Next Generation Wide field Multi object Spectroscopy written by Michael J. I. Brown and published by . This book was released on 2001 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Astronomy from Wide Field Imaging written by H.T. MacGillivray and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt: H.T. MacGilLIVRAY Royal Observatory Blackford Hill Edinburgh EH9 3HJ Scotland U.K. lAU Symposium No. 161 on 'Astronomy from Wide-Field Imaging', held in Potsdam, Germany, during 23-27th August 1993, was the first conference organised by the recently-formed Working Group of lAU Commission 9 on 'Wide-Field Imaging'. This Working Group was instigated during the XXIst meeting of the General Assembly of the International Astronomical Union in Buenos Aires in 1991, and represented a merging of the former formal lAU Working Group on 'Astronomical Photography' and the informal 'Digitised Optical Sky Surveys' Working Group. Dr. Richard West was 'invited' to be Chairperson, and hence was given the daunting task of organising the Group from scratch. The very fact that the first conference after only two years was a major lAU Symposium says much about the determination and enthusiasm of Richard West to fulfilling the aims of the new Working Group. The siting of the conference in Potsdam in formerly East Germany provided an excellent opportunity to advantage from the political changes in Eastern Europe. Good access to the meeting was possible by scientists from Eastern European countries, allowing exchange of information on the very important Wide-Field facilities in both East and West, information on the rich archives of photographic plates that exist in both East and West, and allowing discussions between scientists facing very similar problems in both East and West.

Download or read book Wide Field Spectroscopy and the Distant Universe written by Steve J. Maddox and published by World Scientific Publishing Company Incorporated. This book was released on 1995 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wide Field Spectroscopy and the Distant Universe written by Steve J. Maddox and published by . This book was released on 1995 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific Requirements for Extremely Large Telescopes IAU S232 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2006-06-15 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings volume for researchers and graduate students of astronomy, covering the most exciting science and key ELT projects.

Download or read book Optical 3D Spectroscopy for Astronomy written by Roland Bacon and published by John Wiley & Sons. This book was released on 2017-06-19 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last 50 years, a variety of techniques have been developed to add a third dimension to regular imaging, with an extended spectrum associated to every imaging pixel. Dubbed 3D spectroscopy from its data format, it is now widely used in the astrophysical domain, but also inter alia for atmospheric sciences and remote sensing purposes. This is the first book to comprehensively tackle these new capabilities. It starts with the fundamentals of spectroscopic instruments, in particular their potentials and limits. It then reviews the various known 3D techniques, with particular emphasis on pinpointing their different `ecological? niches. Putative users are finally led through the whole observing process, from observation planning to the extensive ? and crucial - phase of data reduction. This book overall goal is to give the non-specialist enough hands-on knowledge to learn fast how to properly use and produce meaningful data when using such a 3D capability.

Download or read book Modulated Imaging written by David John Cuccia and published by . This book was released on 2006 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modulated Imaging (MI) is a fast, scan-free method that enables one to image and quantify the optical properties of turbid media. The technology can simultaneously map surface and sub-surface tissue structure, function and composition. Based on frequency-domain measurement principles, MI uses spatially-periodic or "structured" illumination and camera-based detection to separate and quantify the absorption, scattering, and fluorescence optical properties over a wide field-of-view (many cm) without the need for sample contact. Resolution is depth-dependent and thus scalable (sub-millimeter to millimeter), with depth sensitivity up to a few cm. This method has particularly strong potential for in-vivo clinical and pre-clinical imaging, where optical properties at several wavelengths provide quantitative information on endogeneous chromophore concentrations (i.e. oxy- and deoxy-hemoglobin, fat, and water). These parameters reflect quantitative, localized tissue status such as blood volume, tissue oxygenation, and edema. Using multispectral MI instrumentation, demonstrations of two in-vivo applications are investigated: (1) pre-clinical functional imaging of brain injury in a rodent model and (2) clinical imaging spectroscopy of human skin. Also, preliminary 3D fluorescence tomography data suggest that MI may provide a convenient, low-cost platform for localizing and quantifying exogenous molecular probes in-vivo.

Download or read book Time correlated single photon counting written by Desmond O'Connor and published by Academic Press. This book was released on 2012-12-02 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: Time-correlated Single Photon Counting has been written in the hope that by relating the authors' experiences with a variety of different single photon counting systems, they may provide a useful service to users and potential users of this formidably sensitive technique. Of all the techniques available to obtain information on the rates of depopulation of excited electronic singlet states of molecular species, monitoring of fluorescence provides, in principle, the simplest and most direct measure of concentration. This volume comprises eight chapters, with the first focusing on the time dependence and applications of fluorescence. Succeeding chapters go on to discuss basic principles of the single photon counting lifetime measurement; light sources; photomultipliers; electronics; data analysis; nanosecond time-resolved emission spectroscopy; time dependence of fluorescence anisotropy. This book will be of interest to practitioners in the field of chemistry.

Download or read book Integral Field Spectroscopy as a Probe of Galaxy Evolution written by Joshua Jesse Adams and published by . This book was released on 2011 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical spectroscopy and modeling are applied to four independent problems related to the structure and evolution of galaxies. The problems cover a broad range of look-back time and galaxy mass. Integral field spectroscopy with low surface brightness sensitivity is the tool employed to advance our understanding of the distribution, interplay, and evolution of the stars, dark matter, and gas. First, I review development and commissioning work done on the VIRUS-P instrument. I then present a large sample of galaxies over redshifts 1.9z & lt;3.8 selected solely through their Lyman-alpha flux. This work is done as a pilot survey to the Hobby-Eberly Telescope Dark Energy eXperiment (HETDEX). I create a redshift catalog of 397 galaxies discovered over 169 square arcsecs taken over 113 nights. Second, I study a high redshift (z=3.4) radio galaxy halo by mapping the Lyman-alpha velocity field. The signal extends far beyond the optical and radio extents of the system. Plausible, but non-unique, models are made to explain the Lyman-alpha signal that require a very large reservoir of neutral hydrogen (= 10E12 solar masses). Third, I study the dark matter halo profile in a nearby late-type dwarf galaxy in the context of the "core-cusp" controversy. N-body simulations predict such galaxies to have cuspy dark matter halos, while HI rotation curves and more recent hydrodynamical simulations indicate that such halos may instead be strongly cored. I measure the spatially resolved stellar velocity field and fit with two-integral Jeans models. A cuspy halo is preferred from the stellar kinematics. The mass models from stellar and gaseous kinematics disagree. The gas models assume circular motion in an infinitely thin disk which is likely unrealistic. The stellar kinematics presented are the first measurements of a collision-less tracer in such galaxies. Fourth, I attempt to measure diffuse H-alpha emission, fluoresced by the metagalactic UV background, in the outskirts of a nearby gas rich galaxy. I do not make a detection, but the deep flux limit over a large field-of-view places the most sensitive limit to-date on the UV background's photoionization rate of Gamma(z=0) & lt;1.7x10E-14 1/s at 5 sigma certainty.

Download or read book Thirty Years of Astronomical Discovery with UKIRT written by Andy Adamson and published by Springer Science & Business Media. This book was released on 2013-11-26 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: These are the proceedings of an international meeting hosted by the Royal Observatory, Edinburgh, to commemorate the 30th anniversary of the dedication of the UKIRT, the United Kingdom InfraRed Telescope. The volume comprises 31 professional level papers. The first part of the book has 10 thorough reviews of the conception, design and build of the telescope, as well as accounts of some its key instruments such as IRCAM (the common-user infrared camera), CGS4 (the fourth Cooled Grating Spectrometer) and the Wide Field Camera. The second part of the book comprises 14 reviews of scientific achievements during its twenty years of visitor mode operations. The final part of the book is a series of 7 reviews of the results from the multiple surveys being done as part of UKIDSS (UKIRT Infrared Deep Sky Survey). The authors are all experts in their respective fields, for example instrument scientists, operations staff and leading astronomers.

Download or read book Spatio spectral Interferometric Imaging and the Wide field Imaging Interferometry Testbed written by Alexander S. Iacchetta and published by . This book was released on 2018 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The light collecting apertures of space telescopes are currently limited in part by the size and weight restrictions of launch vehicles, ultimately limiting the spatial resolution that can be achieved by the observatory. A technique that can overcome these limitations and provide superior spatial resolution is interferometric imaging, whereby multiple small telescopes can be combined to produce a spatial resolution comparable to a much larger monolithic telescope. In astronomy, the spectrum of the sources in the scene are crucial to understanding the material composition of the sources. So, the ultimate goal is to have high-spatial-resolution imagery and obtain sufficient spectral resolution for all points in the scene. This goal can be accomplished through spatiospectral interferometric imaging, which combines the aperture synthesis aspects of a Michelson stellar interferometer with the spectral capabilities of Fourier transform spectroscopy. Spatio-spectral interferometric imaging can be extended to a wide-field imaging modality, which increases the collecting efficiency of the technique. This is the basis for NASA's Wide-field Imaging Interferometry Testbed (WIIT). For such an interferometer, there are two light collecting apertures separated by a variable distance known as the baseline length. The optical path in one of the arms of the interferometer is variable, while the other path delay is fixed. The beams from both apertures are subsequently combined and imaged onto a detector. For a fixed baseline length, the result is many low-spatial-resolution images at a slew of optical path differences, and the process is repeated for many different baseline lengths and orientations. Image processing and synthesis techniques are required to reduce the large dataset into a single high-spatial-resolution hyperspectral image. Our contributions to spatio-spectral interferometry include various aspects of theory, simulation, image synthesis, and processing of experimental data, with the end goal of better understanding the nature of the technique. We present the theory behind the measurement model for spatio-spectral interferometry, as well as the direct approach to image synthesis. We have developed a pipeline to preprocess experimental data to remove unwanted signatures in the data and register all image measurements to a single orientation, which leverages information about the optical system's point spread function. In an experimental setup, such as WIIT, the reference frame for the path difference measured for each baseline is unknown and must be accounted for. To overcome this obstacle, we created a phase referencing technique that leverages point sources within the scene of known separation in order to recover unknown information regarding the measurements in a laboratory setting. We also provide a method that allows for the measurement of spatially and spectrally complicated scenes with WIIT by decomposing them prior to scene projection"--Pages xii-xiii.

Download or read book Observing the Effect of Galaxy Environment on the Evolution of Active Galactic Nuclei in the Era of Multiplexed Wide field Fibre optic Spectroscopy written by Yjan Arthur Gordon and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Wide Field Narrowband Survey for Star Forming Galaxies at Different Epochs written by Everhardus Antonius Metske Westra and published by . This book was released on 2007 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Narrowband surveys are a well-established tool for finding star-forming galaxies at different epochs. This thesis presents the Wide Field Imager Lyman Alpha Search (WFILAS), a survey originally designed to find Lyman-a (Lya) emission-line galaxies at redshift z~5.7, and subsequently utilised to find Hydrogen-a (Ha) emitting galaxies at redshift z~0.24. The survey covers three 0.25 sq. deg. fields each observed in three narrowband filters, an intermediate band filter (encompassing all narrowband filters), and two broadband filters. A sample of seven luminous Lya-emitting galaxies was identified (Lya luminosity greater than or equal to 1.8e43 ergs), complementing existing surveys by further constraining the bright end of the Lya luminosity function. Three candidates identified in one of the three fields, the well-studied Chandra Deep Field South, were grouped together, supporting claims of an overdensity at this redshift by other groups. Two of the seven candidate Lya emitting galaxies have been confirmed through spectroscopy, one of which is the most luminous at this redshift to date. The spectra of both objects displayed the asymmetric line profiles common in Lya at these redshifts. Furthermore, tentative evidence of a second Lya component, redward of the Lya line was found. Additional high-resolution imaging showed that both objects were unresolved. Spectroscopic follow-up was used to determine the fraction of Ha-emitting galaxies in two of the fields from a total sample of 707 candidate emission line galaxies. This yielded two independent Ha luminosity functions and star formation densities at z ~ 0.24 following corrections for extinction, imaging and spectroscopic incompleteness. These values were found to agree with those of other recent surveys within the limits of uncertainty. A detailed error analysis found that both cosmic variance and differences in selection criteria remain the dominant sources of uncertainty between various Ha luminosity functions at z smaller than or equal to 0.4. While the star formation rates were consistent with the typical field galaxy densities probed by the fields, a tentative increase in star formation rate per galaxy with increasing density of star forming galaxies was found. This observation supports galaxy formation scenarios in which galaxy-galaxy interactions are triggers for star formation.