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Sample records for vlt unit telescopes

  1. VLT Unit Telescopes Named at Paranal Inauguration

    Science.gov (United States)

    1999-03-01

    This has been a busy, but also a very successful and rewarding week for the European Southern Observatory and its staff. While "First Light" was achieved at the second 8.2-m VLT Unit Telescope (UT2) ahead of schedule, UT1 produced its sharpest image so far. This happened at a moment of exceptional observing conditions in the night between March 4 and 5, 1999. During a 6-min exposure of the majestic spiral galaxy, NGC 2997 , stellar images of only 0.25 arcsec FWHM (full-width half-maximum) were recorded. This and two other frames of nearly the same quality have provided the base for the beautiful colour-composite shown above. At this excellent angular resolution, individual star forming regions are well visible along the spiral arms. Of particular interest is the peculiar, twisted shape of the long spiral arm to the right. The Paranal Inauguration The official inauguration of the Paranal Observatory took place in the afternoon of March 5, 1999, in the presence of His Excellency, the President of the Republic of Chile, Don Eduardo Frei Ruiz-Tagle, and ministers of his cabinet, as well the Ambassadors to Chile of the ESO member states and many other distinguished guests. The President of the ESO Council, Mr. Henrik Grage, and the ESO Director General, Professor Riccardo Giacconi, were the foremost representatives of the ESO organisation; most members of the ESO Council and ESO staff also participated. A substantial number of media representatives from Europe and Chile were present and reported - often live - from Paranal during the afternoon and evening. The guests were shown the impressive installations at the new observatory, including the first and second 8.2-m VLT Unit Telescopes; the latter having achieved "First Light" just four days before. A festive ceremony took place in the dome of UT2, under the large telescope structure that had been tilted towards the horizon to make place for the numerous participants. After an introductory address by the ESO Director

  2. Two VLT 8.2-m Unit Telescopes in Action

    Science.gov (United States)

    1999-04-01

    Visitors at ANTU - Astronomical Images from KUEYEN The VLT Control Room at the Paranal Observatory is becoming a busy place indeed. From here, two specialist teams of ESO astronomers and engineers now operate two VLT 8.2-m Unit Telescopes in parallel, ANTU and KUEYEN (formerly UT1 and UT2, for more information about the naming and the pronunciation, see ESO Press Release 06/99 ). Regular science observations have just started with the first of these giant telescopes, while impressive astronomical images are being obtained with the second. The work is hard, but the mood in the control room is good. Insiders claim that there have even been occasions on which the groups have had a friendly "competition" about which telescope makes the "best" images! The ANTU-team has worked with the FORS multi-mode instrument , their colleagues at KUEYEN use the VLT Test Camera for the ongoing tests of this new telescope. While the first is a highly developed astronomical instrument with a large-field CCD imager (6.8 x 6.8 arcmin 2 in the normal mode; 3.4 x 3.4 arcmin 2 in the high-resolution mode), the other is a less complex CCD camera with a smaller field (1.5 x 1.5 arcmin 2 ), suited to verify the optical performance of the telescope. As these images demonstrate, the performance of the second VLT Unit Telescope is steadily improving and it may not be too long before its optical quality will approach that of the first. First KUEYEN photos of stars and galaxies We present here some of the first astronomical images, taken with the second telescope, KUEYEN, in late March and early April 1999. They reflect the current status of the optical, electronic and mechanical systems, still in the process of being tuned. As expected, the experience gained from ANTU last year has turned out to be invaluable and has allowed good progress during this extremely delicate process. ESO PR Photo 19a/99 ESO PR Photo 19a/99 [Preview - JPEG: 400 x 433 pix - 160k] [Normal - JPEG: 800 x 866 pix - 457k] [High

  3. VLT 8.2-m Unit Telescope no. 1 (as on September 7, 1995)

    Science.gov (United States)

    1995-09-01

    ESO Press Photos 28-30/95; 13 September 1995 The construction of the ESO Very Large Telescope (VLT) advances rapidly, both in Europe and in Chile. These three photos show some of the main mechanical parts of the first 8.2-metre telescope, as they presented themselves in Milan (Italy) on Thursday, September 7, 1995. Two versions of these photos, one smaller and one larger and with better image resolution, are accessible for convenient transfer over the networks. The mechanical structure of VLT Unit Telescope no. 1 is now in the process of being mounted at the Ansaldo Energia premises in Milan (Italy). The so-called main structure (i.e., telescope azimuth and altitude mechanical structure, including hydrostatic bearing system, direct drives and direct mounted encoding system) was designed and is being built by the Italian consortium AES, composed of Ansaldo Energia (Genova), SOIMI (Milan) and EIE (Venice). Already two months from now, in November 1995, the complete, enormous mechanical structures of this telescope will be moving on the azimuth hydrostatic bearing tracks, using the direct drive system designed and built by the PHASE Company (Genova, Italy). The thorough testing phase will start by the end of December 1995 or at the beginning of January 1996. ESO Press Photo 28/95 [54K] [248K] shows the lower part of the azimuth structure of the telescope (the fork) on the concrete pier on which the azimuth tracks (hydrostatic bearing journal) are mounted. The very high accuracy of this enormous structure (compare with the persons in the photo!) is illustrated by the fact that the "run-out" of the azimuth axis of the fork has been measured as only 80 microns (0.08 millimetres) on 90 degrees turning angle. This is a remarkable result, especially since the centering of the axis is done on a radial journal with a diameter of no less than 9 metres. When the fork is equipped with all auxiliary systems, it will weigh about 320 t, will be 18 metres long and 8 metres wide. It

  4. Design, fabrication, integration and commissioning of an upgraded guiding probe for the VLT unit telescope 4

    Science.gov (United States)

    Frank, Christoph; Hammersley, Peter; Buzzoni, Bernard; Manescau, Antonio; Arsenault, Robin; Madec, Pierre-Yves; Birkmann, Martin; Mueller, Michael; Salgado, Fernando; Guisard, Stephane; Kroedel, Matthias

    2014-07-01

    As part of the preparation for the arrival of the MUSE instrument to the VLT, it was required to adapt the hosting telescope (UT4) guide probe, to increase its back focal length. This is to allow enough space for the later deployment of the MUSE Adaptive Optics module GALACSI, in-between the telescope adapter rotator and the instrument itself. The UT guide probe is a critical component for the successful operation of the telescope, so its modification to increase the telescope's back focal length, while maintaining full compatibility with the existing operation model and other hardware, was rather demanding. The design, manufacture, assembly and test for the new supporting arm in the UT guiding probe is presented. It mixes the use of novel materials (HB-CESIC® for the mirrors substrates) and state of the art manufacturing techniques (3D printing mould production and rapid casting for the support structure), which allow producing easily a high performance subsystem. Characterization of the system prior delivery to the telescope, its integration in the UT and results after commissioning is presented. Its successful implementation has validated new manufacturing techniques that may prove very useful for future instruments development.

  5. The European Southern Observatory and VLT telescopes on Paranal

    Science.gov (United States)

    Boley, P. A.

    2012-01-01

    The Very Large Telescope (VLT) of the European Southern Observatory (ESO) on Cerro Paranal is one of the most influential observing complexes in the world. In this overview lecture, an introduction to the ESO organization and VLT telescopes is presented, along with a small selection of scientific works. Particular attention is given to the importance of the VLT for the Russian scientific community, as well as to present and future perspectives for making use of ESO and VLT data.

  6. VLT telescope control software: status, development, and lessons learned

    Science.gov (United States)

    Wirenstrand, Krister

    2003-02-01

    The four 8m VLT telescopes on Paranal are now in full science operation, and they all deliver good results with very small technical downtimes. Of course, many factors are contributing to these results, and also the telescope control software has its share. It has demonstrated to be robust and reliable and also flexible and expandable. In the four years since First Light of the first VLT telescope, this software has been continuously maintained and developed, for improvements on the 8m telescopes but also for use on other telescopes. In addition to the 8m ones, another three telescopes, using applicable parts of the same software, are in operation on Paranal: the 350- mm seeing monitor and two 400-mm siderostats. And the process continues: in the beginning of 2003 the first of three 1.8m Auxiliary Telescopes for the VLT Interferometer will be installed; the control software to 80% being the same as for the 8m telescopes, but with additional devices and control functionality. Another three ESO telescopes on La Silla are also using the same software, as well as two wide field telescopes for Paranal that are now in the design and manufacturing phase. In this development process, and in particular after first installation, we have learned lessons in many areas of software project work. System design and engineering, standardization, tools, testing: these are example areas where there is always room for improvement. Another lesson learned is the importance of the concept of Commissioning, i.e. the work to take the telescope from "integrated" to "working"! What the future of telescope control software will be, that we don't know, but we are working on it! And we try to keep an evolutionary approach, taking advantage of the lessons learned.

  7. The VLT Adaptive Optics Facility Project: Telescope Systems

    Science.gov (United States)

    Arsenault, Robin; Hubin, Norbert; Stroebele, Stefan; Fedrigo, Enrico; Oberti, Sylvain; Kissler-Patig, Markus; Bacon, Roland; McDermid, Richard; Bonaccini-Calia, Domenico; Biasi, Roberto; Gallieni, Daniele; Riccardi, Armando; Donaldson, Rob; Lelouarn, Miska; Hackenberg, Wolfgang; Conzelman, Ralf; Delabre, Bernard; Stuik, Remko; Paufique, Jerome; Kasper, Markus; Vernet, Elise; Downing, Mark; Esposito, Simone; Duchateau, Michel; Franx, Marijn; Myers, Richard; Goodsell, Steven

    2006-03-01

    The Adaptive Optics Facility is a project to convert UT4 into a specialised Adaptive Telescope. The present secondary mirror (M2) will be replaced by a new M2-Unit hosting a 1170-actuator deformable mirror. The three focal stations will be equipped with instruments adapted to the new capability of this UT. Two instruments have been identified for the two Nasmyth foci: Hawk-I with its AO module GRAAL allowing a Ground Layer Adaptive Optics correction and MUSE with GALACSI for GLAO correction and Laser Tomography Adaptive Optics correction. A future instrument still needs to be defined for the Cassegrain focus. Several guide stars are required for the type of adaptive corrections needed and a Four Laser Guide Star Facility (4LGSF) is being developed in the scope of the AO Facility. Convex mirrors like the VLT M2 represent a major challenge for testing and a substantial effort is dedicated to this. ASSIST, is a test bench that will allow testing of the Deformable Secondary Mirror and both instruments with simulated turbulence. This article focusses on the telescope systems (Adaptive Secondary, Four Laser Guide Star Facility, RTC platform and ASSIST Test Bench). The following article describes the AO Modules GALACSI and GRAAL.

  8. OmegaCAM: the 16k × 16k Survey Camera for the VLT Survey Telescope

    NARCIS (Netherlands)

    Deul, Erik; Kuijken, Konrad; Valentijn, Edwin A.; Tyson, J. Anthony; Wolff, Sidney

    2002-01-01

    OmegaCAM, a 16k×16k-pixel wide field optical camera, and the VLT Survey Telescope (VST) that is to host it, will constitute a major sky surveying machine that becomes operational in 2004 at ESO"s Paranal Observatory. It maps one square degree of sky with 0.21 arcsec sized pixels. Both individual pro

  9. Data Mining for Double Stars on VLT Survey Telescope Image Archive

    Science.gov (United States)

    Curelaru, Lucian

    2017-04-01

    The article presents a set of methods and tools used to identify and measure double stars on already existing images produced by the ESO VLT Survey Telescope in Paranal Chile. A precision analysis and a first set of measurements are included.

  10. The OmegaCAM 16K x 16K CCD detector system for the ESO VLT Survey Telescope (VST)

    NARCIS (Netherlands)

    Iwert, Olaf; Baade, D.; Balestra, A.; Baruffolo, A.; Bortolussi, A.; Christen, F.; Cumani, C.; Deiries, S.; Downing, M.; Geimer, C.; Hess, G.; Hess, J.; Kuijken, K.; Lizon, J.; Muschielok, B.; Nicklas, H.; Reiss, R.; Reyes, J.; Silber, A.; Thillerup, J.; Valentijn, E.; Dorn, David A.; Holland, Andrew D.

    2006-01-01

    A 16K x 16K, 1 degree x 1 degree field, detector system was developed by ESO for the OmegaCAM instrument for use on the purpose built ESO VLT Survey Telescope (VST). The focal plane consists of an 8 x 4 mosaic of 2K x 4K 15um pixel e2v CCDs and four 2K x 4K CCDs on the periphery for the opto-mechani

  11. Deep Impact High Resolution Optical Spectroscopy with the ESO VLT and the Keck 1 telescope

    CERN Document Server

    Jehin, E; Cochran, A L; Hutsemékers, D; Jackson, W M; Manfroid, J; Rauer, H; Schulz, R; Zucconi, J M

    2006-01-01

    We report on observations of comet 9P/Tempel 1 carried out before, during, and after the NASA DEEP IMPACT event (UT July 4), with the optical spectrometers UVES and HIRES mounted on the telescopes Kueyen of the ESO VLT (Chile) and Keck 1 on Mauna Kea (Hawaii), respectively. A total observing time of about 60 hours, distributed over 15 nights around the impact date, allowed us (i) to find a periodic variation of 1.709 +/- 0.009 day in the CN and NH flux, explained by the presence of two major active regions; (ii) to derive a lifetime > ~ 5 x 10^4 s for the parent of the CN radical from a simple modeling of the CN light curve after the impact; (iii) to follow the gas and dust spatial profiles evolution during the 4 hours following the impact and derive the projected velocities (400 m/s and 150 m/s respectively); (iv) to show that the material released by the impact has the same carbon and nitrogen isotopic composition as the surface material (12C/13C = 95 +/- 15 and 14N/15N = 145 +/- 20).

  12. Happy Anniversary, VLT !

    Science.gov (United States)

    2004-04-01

    Five years at the service of Europe's astronomers VLT 5 Years One of the world's most advanced astronomical research facilities, the ESO Very Large Telescope (VLT) at the Paranal Observatory in the Chilean Atacama desert, celebrates an important anniversary today. On April 1, 1999, and following almost one year of extensive tests and careful trimming of its numerous high-tech parts, the first 8.2-m VLT Unit Telescope, Antu (UT1), was "handed over" to the astronomers. Since that date, science operations with this marvellous research tool have been continuous and intensive. Kueyen (UT2) started normal operations exactly one year later. Yepun (UT4) was offered to the scientific community in June 2001, while Melipal (UT3) followed in August 2001 [1]. Ever since, all four VLT Unit Telescopes, with an ever-growing suite of highly specialised, extremely powerful astronomical instruments have been in full operation, 365 nights a year. And this with unequalled success, as demonstrated by a long list of important scientific results, including a substantial number of exciting discoveries that are now opening new horizons in astrophysics. Moreover, thanks to heroic and persistent efforts by the dedicated teams of ESO scientists and engineers, the "downtime" due to technical problems has been very small, about 3 per cent, a number that is unequalled among the world's large telescope facilities. In addition, the weather conditions at the Paranal site in the dry Atacama desert in Northern Chile are truly excellent - this is indeed one of the best locations for astronomical observations on the surface of the Earth - and the corresponding "weather downtime" has only been around 10 per cent. This has resulted in an unbelievably low value of total downtime, most likely a new world record for ground-based 8-10 m class telescopes. VLT strong points The Very Large Telescope (VLT) is the world's largest and most advanced optical telescope. It comprises four 8.2-m reflecting Unit

  13. Beam combination modes of the VLT

    Science.gov (United States)

    Merkle, Fritz

    The optical configuration of the ESO Very Large Telescope (VLT) is based on a linear array of 4 independently mounted 8-m telescopes. This concept allows a flexible and versatile use of the telescopes. They can be operated either independently or in various combination schemes. In the latter case, the light collected with the unit telescopes is fed via beam combination optics to the combined focus. The incoherent combination with a combined coude focus offers the light collecting power approximately equivalent to a 16-m single dish telescope. The efficiency of the combined foci operation is only given if the losses in the combining train are minimized.

  14. Progress on the VLT Adaptive Optics Facility

    Science.gov (United States)

    Arsenault, R.; Madec, P.-Y.; Paufique, J.; Ströbele, S.; Pirard, J.-F.; Vernet, É.; Hackenberg, W.; Hubin, N.; Jochum, L.; Kuntschner, H.; Glindemann, A.; Amico, P.; Lelouarn, M.; Kolb, J.; Tordo, S.; Donaldson, R.; Sã¶Nke, C.; Bonaccini Calia, D.; Conzelmann, R.; Delabre, B.; Kiekebusch, M.; Duhoux, P.; Guidolin, I.; Quattri, M.; Guzman, R.; Buzzoni, B.; Comin, M.; Dupuy, C.; Quentin, J.; Lizon, J.-L.; Silber, A.; Jolly, P.; Manescau, A.; Hammersley, P.; Reyes, J.; Jost, A.; Duchateau, M.; Heinz, V.; Bechet, C.; Stuik, R.

    2010-12-01

    The Very Large Telescope (VLT) Adaptive Optics Facility is a project that will transform one of the VLT's Unit Telescopes into an adaptive telescope that includes a deformable mirror in its optical train. For this purpose the secondary mirror is to be replaced by a thin shell deformable mirror; it will be possible to launch four laser guide stars from the centrepiece and two adaptive optics modules are being developed to feed the instruments HAWK-I and MUSE. These modules implement innovative correction modes for seeing improvement through ground layer adaptive optics and, for high Strehl ratio performance, laser tomography adaptive correction. The performance of these modes will be tested in Europe with a custom test bench called ASSIST. The project has completed its final design phase and concluded an intense phase of procurement; the year 2011 will see the beginning of assembly, integration and tests.

  15. VLT Data Flow System Begins Operation

    Science.gov (United States)

    1999-06-01

    Building a Terabyte Archive at the ESO Headquarters The ESO Very Large Telescope (VLT) is the sum of many sophisticated parts. The site at Cerro Paranal in the dry Atacama desert in Northern Chile is one of the best locations for astronomical observations from the surface of the Earth. Each of the four 8.2-m telescopes is a technological marvel with self-adjusting optics placed in a gigantic mechanical structure of the utmost precision, continuously controlled by advanced soft- and hardware. A multitude of extremely complex instruments with sensitive detectors capture the faint light from distant objects in the Universe and record the digital data fast and efficiently as images and spectra, with a minimum of induced noise. And now the next crucial link in this chain is in place. A few nights ago, following an extended test period, the VLT Data Flow System began providing the astronomers with a steady stream of high-quality, calibrated image and spectral data, ready to be interpreted. The VLT project has entered into a new phase with a larger degree of automation. Indeed, the first 8.2-m Unit Telescope, ANTU, with the FORS1 and ISAAC instruments, has now become a true astronomy machine . A smooth flow of data through the entire system ESO PR Photo 25a/99 ESO PR Photo 25a/99 [Preview - JPEG: 400 x 292 pix - 104k] [Normal - JPEG: 800 x 584 pix - 264k] [High-Res - JPEG: 3000 x 2189 pix - 1.5M] Caption to ESO PR Photo 25a/99 : Simplified flow diagramme for the VLT Data Flow System . It is a closed-loop software system which incorporates various subsystems that track the flow of data all the way from the submission of proposals to storage of the acquired data in the VLT Science Archive Facility. The DFS main components are: Program Handling, Observation Handling, Telescope Control System, Science Archive, Pipeline and Quality Control. Arrows indicate lines of feedback. Already from the start of this project more than ten years ago, the ESO Very Large Telescope was

  16. With the VLT Interferometer towards Sharper Vision

    Science.gov (United States)

    2000-05-01

    ESO PR Photo 14a/00 [Preview - JPEG: 359 x 400 pix - 120k] [Normal - JPEG: 717 x 800 pix - 416k] [High-Res - JPEG: 2689 x 3000 pix - 6.7M] Caption : A view of the Paranal platform with the four 8.2-m VLT Unit Telescopes (UTs) and the foundations for the 1.8-m VLT Auxiliary Telescopes (ATs) that together will be used as the VLT Interferometer (VLTI). The three ATs will move on rails (yet to be installed) between the thirty observing stations above the holes that provide access to the underlying tunnel system. The light beams from the individual telescopes will be guided towards the centrally located, partly underground Interferometry Laboratory in which the VLTI instruments will be set up. This photo was obtained in December 1999 at which time some construction materials were still present on the platform; they were electronically removed in this reproduction. The ESO VLT facility at Paranal (Chile) consists of four Unit Telescopes with 8.2-m mirrors and several 1.8-m auxiliary telescopes that move on rails, cf. PR Photo 14a/00 . While each of the large telescopes can be used individually for astronomical observations, a prime feature of the VLT is the possibility to combine all of these telescopes into the Very Large Telescope Interferometer (VLTI) . In the interferometric mode, the light beams from the VLT telescopes are brought together at a common focal point in the Interferometry Laboratory that is placed at the centre of the observing platform on top of Paranal. In principle, this can be done in such a way that the resulting (reconstructed) image appears to come from a virtual telescope with a diameter that is equal to the largest distance between two of the individual telescopes, i.e., up to about 200 metres. The theoretically achievable image sharpness of an astronomical telescope is proportional to its diameter (or, for an interferometer, the largest distance between two of its component telescopes). The interferometric observing technique will thus allow the

  17. Multiple Eyes for the VLT

    Science.gov (United States)

    2002-01-01

    First System of Deployable Multi-Integral Field Units Ready Summary The ESO Very Large Telescope (VLT) at the Paranal Observatory is being equipped with many state-of-the-art astronomical instruments that will allow observations in a large number of different modes and wavebands. Soon to come is the Fibre Large Array Multi-Element Spectrograph (FLAMES) , a project co-ordinated by ESO. It incorporates several complex components, now being constructed at various research institutions in Europe and Australia. One of these, a true technological feat, is a unique system of 15 deployable fibre bundles, the so-called Integral Field Units (IFUs) . They can be accurately positioned within a sky field-of-view measuring no less that 25 arcmin in diameter, i.e., almost as large as the full Moon . Each of the IFUs looks like an insect's eye and images a small sky area (3 x 2 arcsec 2 ) with a multiple microlens. From each IFU, 20 narrow light beams are sent via optical fibres to an advanced spectrograph. All 300 spectra are recorded simultaneously by a sensitive digital camera. A major advantage of this technique is that, contrary usual spectroscopic observations in which spectral information is obtained along a (one-dimensional) line on the sky, it now allows (two-dimensional) area spectroscopy . This will permit extremely efficient spectral observations of many celestial objects, including faint galaxies, providing detailed information about their internal structure and motions. Such studies will have an important impact on our understanding, e.g., of the early evolution of galaxies , the main building blocks in the Universe. The IFUs have been developed by a team of astronomers and engineers [2] at the Observatoire de Paris-Meudon. All IFU components are now at the ESO Headquarters in Garching (Germany) where they are being checked and integrated into the instrument [3]. PR Photo 03a/02 : The GIRAFFE spectrograph in the ESO Assembly Hall (Garching, Germany) . PR Photo 03b/02

  18. The optical detection unit for Baikal-GVD neutrino telescope

    Directory of Open Access Journals (Sweden)

    Avrorin A.D.

    2016-01-01

    Full Text Available The first stage of the GVD-cluster composed of five strings was deployed in April 2014. Each string consists of two sections with 12 optical modules per section. A section is the basic detection unit of the Baikal neutrino telescope. We will describe the section design, review its basic elements – optical modules, FADC readout units, slow control and calibration systems, and present selected results for section in-situ tests in Lake Baikal.

  19. A 200-GHz telescope unit for the QUIJOTE CMB Experiment

    Science.gov (United States)

    Sanquirce, Rubén.; Etxeita, Borja; Murga, Gaizka; Fernandez, Esther; Sainz, Iñaki; Sánchez, Vicente; Viera-Curbelo, Teodora A.; Gómez, María. F.; Aguiar-Gonzalez, Marta; Hoyland, Roger J.; Pérez de Taoro, Ángeles R.; Vega, Afrodisio; Rebolo-López, Rafael; Rubiño, Jose Alberto

    2014-07-01

    Experiment QUIJOTE (Q-U-I JOint TEnerife) is a scientific collaboration, leaded by the Instituto de Astrofísica de Canarias (IAC), which can measure the polarization of the Cosmic Microwave Background (CMB) in the range of frequency up to 200 GHz, at angular scales of 1°. The project is composed of 2 telescopes and 3 instruments, located in Teide Observatory (Tenerife, Spain). After the successful delivery of the first telescope (operative since 2012), Idom is currently involved on the turn key supply of the second telescope (phase II). The work started in June 2013 and it will be completed in a challenging period of 12 months (operative at the beginning of July 2014), including design, factory assembly and testing, transport and final commissioning on site. This second unit will improve the opto-mechanical performance and maintainability. The telescope will have an unlimited rotation capacity in azimuth axis and a range of movement between 25°-95° in elevation axis. An integrated rotary joint will transmit fluid, power and signal to the rotary elements. The pointing and tracking accuracy will be significantly below to specification: 1.76 arcmin and 44 arcsec, respectively. This project completes Idoḿs contribution during phase I, which also comprises the integration and functional tests for the 5 polarimeters of the first instrument in Bilbao headquarters, and the design and supervision of the building which protects both telescopes, including the installation and commissioning of the mechanism for shutters aperture.

  20. VLT laser guide star facility

    Science.gov (United States)

    Bonaccini, Domenico; Allaert, Eric; Araujo, Constanza; Brunetto, Enzo; Buzzoni, Bernard; Comin, Mauro; Cullum, Martin J.; Davies, Richard I.; Dichirico, Canio; Dierickx, Philippe; Dimmler, Martin; Duchateau, Michel; Egedal, Carsten; Hackenberg, Wolfgang K. P.; Hippler, Stefan; Kellner, Stefan; van Kesteren, Arno; Koch, Franz; Neumann, Udo; Ott, Thomas; Quattri, Marco; Quentin, Jutta; Rabien, Sebastian; Tamai, Roberto; Tapia, Mario; Tarenghi, Massimo

    2003-02-01

    We report on the ongoing VLT Laser Guide Star Facility project, which will allow the ESO UT4 telescope to produce an artificial reference star for the Adaptive Optics systems NAOS-CONICA and SINFONI. A custom developed dye laser producing >10W CW at 589nm is installed on-board of the UT4 telescope, then relayed by means of a single mode optical fiber behind the secondary mirror, where a 500mm diameter lightweight, f/1 launch telescope is projecting the laser beam at 90 km altitude. We described the design tradeoffs and provide some details of the chosen subsystems. This paper is an update including subsystems results, to be read together with our previous paper on LGSF design description.

  1. ESPRESSO: the ultimate rocky exoplanets hunter for the VLT

    Science.gov (United States)

    Mégevand, Denis; Zerbi, Filippo M.; Cabral, Alexandre; Di Marcantonio, Paolo; Amate, Manuel; Pepe, Francesco; Cristiani, Stefano; Rebolo, Rafael; Santos, Nuno C.; Dekker, Hans; Abreu, Manuel; Affolter, Michael; Avila, Gerardo; Baldini, Veronica; Bristow, Paul; Broeg, Christopher; Carvas, Pedro; Cirami, Roberto; Coelho, João.; Comari, Maurizio; Conconi, Paolo; Coretti, Igor; Cupani, Guido; D'Odorico, Valentina; De Caprio, Vincenzo; Delabre, Bernard; Figueira, Pedro; Fleury, Michel; Fragoso, Ana; Genolet, Ludovic; Gomes, Ricardo; Gonzalez Hernandez, Jonay; Hughes, Ian; Iwert, Olaf; Kerber, Florian; Landoni, Marco; Lima, Jorge; Lizon, Jean-Louis; Lovis, Christophe; Maire, Charles; Mannetta, Marco; Martins, Carlos; Moitinho, André; Molaro, Paolo; Monteiro, Manuel; Rasilla, José Luis; Riva, Marco; Santana Tschudi, Samuel; Santin, Paolo; Sosnowska, Danuta; Sousa, Sergio; Spanò, Paolo; Tenegi, Fabio; Toso, Giorgio; Vanzella, Eros; Viel, Matteo; Zapatero Osorio, Maria Rosa

    2012-09-01

    ESPRESSO, the VLT rocky exoplanets hunter, will combine the efficiency of modern echelle spectrograph with extreme radial-velocity precision. It will be installed at Paranal on ESO's VLT in order to achieve a gain of two magnitudes with respect to its predecessor HARPS, and the instrumental radial-velocity precision will be improved to reach 10 cm/s level. We have constituted a Consortium of astronomical research institutes to fund, design and build ESPRESSO on behalf of and in collaboration with ESO, the European Southern Observatory. The project has passed the preliminary design review in November 2011. The spectrograph will be installed at the so-called "Combined Coudé Laboratory" of the VLT, it will be linked to the four 8.2 meters Unit Telescopes (UT) through four optical "Coudé trains" and will be operated either with a single telescope or with up to four UTs. In exchange of the major financial and human effort the building Consortium will be awarded with guaranteed observing time (GTO), which will be invested in a common scientific program. Thanks to its characteristics and the ability of combining incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in many fields of astronomy. Our main scientific objectives are, however, the search and characterization of rocky exoplanets in the habitable zone of quiet, near-by G to M-dwarfs, and the analysis of the variability of fundamental physical constants. In this paper, we present the ambitious scientific objectives, the capabilities of ESPRESSO, the technical solutions for the system and its subsystems, enlightening the main differences between ESPRESSO and its predecessors. The project aspects of this facility are also described, from the consortium and partnership structure to the planning phases and milestones.

  2. A new Cassegrain calibration lamp unit for the Blanco Telescope

    Science.gov (United States)

    Points, S. D.; James, D. J.; Tighe, R.; Montané, A.; David, N.; Martínez, M.

    2016-08-01

    The f/8 RC-Cassegrain Focus of the Blanco Telescope at Cerro Tololo Inter-American Observatory, hosts two new instruments: COSMOS, a multi-object spectrograph in the visible wavelength range (350 - 1030nm), and ARCoIRIS, a NIR cross-dispersed spectrograph featuring 6 spectral orders spanning 0.8 - 2.45μm. Here we describe a calibration lamp unit designed to deliver the required illumination at the telescope focal plane for both instruments. These requirements are: (1) an f/8 beam of light covering a spot of 92mm diameter (or 10 arcmin) for a wavelength range of 0.35μm through 2.5μm and (2) no saturation of flat-field calibrations for the minimal exposure times permitted by each instrument, and (3) few saturated spectral lines when using the wavelength calibration lamps for the instruments. To meet these requirements this unit contains an adjustable quartz halogen lamp for flat-field calibrations, and one hollow cathode lamp and four penray lamps for wavelength calibrations. The wavelength calibration lamps are selected to provide optimal spectral coverage for the instrument mounted and can be used individually or in sets. The device designed is based on an 8-inch diameter integrating sphere, the output of which is optimized to match the f/8 calibration input delivery system which is a refractive system based on fused-silica lenses. We describe the optical design, the opto-mechanical design, the electronic control and give results of the performance of the system.

  3. Ten years maintaining MACAO-VLTI units in operation in the Very Large Telescope at Paranal Observatory

    Science.gov (United States)

    Salgado, F.; Hudepohl, G.

    2016-07-01

    More than 10 years have already passed since the first Multiple Application Curvature Adaptive Optics (MACAO) facilities got the first light in UT2 the 18th of April, 2003, in the Very Large Telescope (VLT) at Paranal Observatory. The achievable image sharpness of a ground-based telescope is normally limited by the effect of atmospheric turbulence. However, with Adaptive Optics (AO) techniques, this major drawback can be overcome so that the telescope produces images that are as sharp as theoretically possible, i.e., as if they were taken from space. [1] The intention of this document is summarize in few pages some highlights related with the activities needed to keep MACAO units in operation. Some statistics of problems based in Action Remedy tool is included, showing how through these years the number of problems has been reduced, even when there are still some unsolved ones. Some lessons have been learned and there are others one to learn. Corrective and predictive maintenance performed are shown too like the current measurements, transfer functions measurements, thermography pictures, health checks measuring interaction matrix and flat vectors to detect dead APDs or short circuits in the DM, etc. Some forced interventions are included as well like the removal of the cabinets from Coude rooms to avoid that acoustic noise and vibrations perturb the operations, the deformable mirrors reached by cooling leaks and a mirror that got rusty are shown too. Well knowledge of the system, good interaction between different disciplines groups to perform corrective and preventive maintenance seems to be key aspects of keeping it under control and operative during all these years leading to this good result.

  4. Workshop “Science with the VLT in the ELT Era”

    CERN Document Server

    Astrophysics and Space Science Proceedings

    2008-01-01

    The Workshop ‘Science with the VLT in the ELT era’ was organised by ESO as a forum for the astronomical community to debate its expected future use of ESO’s Very Large Telescope ( and its VLTI interferometric mode) when other facilities such as ALMA, JWST and, hopefully, at least one extremely large 30-40m class telescope will be operating. VLT/I science highlights were presented, future science priorities argued, synergies between the VLT and the future facilities confirmed and specific new VLT/I instruments proposed.

  5. ESO VLT laser guide star facility

    Science.gov (United States)

    Bonaccini, Domenico; Hackenberg, Wolfgang K.; Cullum, Martin J.; Brunetto, Enzo; Ott, Thomas; Quattri, Marco; Allaert, Eric; Dimmler, Martin; Tarenghi, Massimo; Van Kersteren, A.; Di Chirico, C.; Buzzoni, Bernard; Gray, Peter; Tamai, R.; Tapia, M.

    2002-02-01

    We report in this paper on the design and progress of the ESO Laser Guide Star Facility. The project will create a user facility embedded in UT4, to produce in the Earth's Mesosphere Laser Guide Stars, which extend the sky coverage of Adaptive Optics systems on the VLT UT4 telescope. Embedded into the project are provisions for multiple LGS to cope with second generation MCAO instruments.

  6. High-contrast imaging of Sirius~A with VLT/SPHERE: Looking for giant planets down to one astronomical unit

    CERN Document Server

    Vigan, A; Salter, G; Mesa, D; Homeier, D; Moutou, C; Allard, F

    2015-01-01

    Sirius has always attracted a lot of scientific interest, especially after the discovery of a companion white dwarf at the end of the 19th century. Very early on, the existence of a potential third body was put forward to explain some of the observed properties of the system. We present new coronagraphic observations obtained with VLT/SPHERE that explore, for the very first time, the innermost regions of the system down to 0.2" (0.5 AU) from Sirius A. Our observations cover the near-infrared from 0.95 to 2.3 $\\mu$m and they offer the best on-sky contrast ever reached at these angular separations. After detailing the steps of our SPHERE/IRDIFS data analysis, we present a robust method to derive detection limits for multi-spectral data from high-contrast imagers and spectrographs. In terms of raw performance, we report contrasts of 14.3 mag at 0.2", ~16.3 mag in the 0.4-1.0" range and down to 19 mag at 3.7". In physical units, our observations are sensitive to giant planets down to 11 $M_{Jup}$ at 0.5 AU, 6-7 $...

  7. The 8.2 metre primary mirrors of the VLT

    Science.gov (United States)

    Dierickx, P.; Enard, D.; Merkle, F.; Noethe, L.; Wilson, R. N.

    1990-08-01

    The Very Large Telescope (VLT) presently being developed at ESO is described in terms of technological advances which make its use both technically effective and feasible. The VLT capitalizes on advances in materials, polishing techniques, and mirror support systems. The VLT consists of four 8-m alt-az telescopes and a 2-m auxiliary telescope in a single-dish configuration with Zerodur meniscus mirrors passively supported on a lateral system. A discussion of the tradeoffs between glass and metal mirrors is presented, and computerized polishing is described in relation to optical specifications. The mirror is supported with 150 axial and 60 lateral supports with electromechanical actuators to modulate applied force. The active optics concept is employed via the flexibility of the primary mirror, which generates elastomechanical deformations and the position and orientation of the secondary mirror.

  8. Obsolescence of electronics at the VLT

    Science.gov (United States)

    Hüdepohl, Gerhard; Haddad, Juan-Pablo; Lucuix, Christian

    2016-07-01

    The ESO Very Large Telescope Observatory (VLT) at Cerro Paranal in Chile had its first light in 1998. Most of the telescopes' electronics components were chosen and designed in the mid 1990s and are now around 20 years old. As a consequence we are confronted with increasing failure rates due to aging and lack of spare parts, since many of the components are no longer available on the market. The lifetime of large telescopes is generally much beyond 25 years. Therefore the obsolescence of electronics components and modules becomes an issue sooner or later and forces the operations teams to upgrade the systems to new technology in order to avoid that the telescope becomes inoperable. Technology upgrade is a time and money consuming process, which in many cases is not straightforward and has various types of complications. This paper shows the strategy, analysis, approach, timeline, complications and progress in obsolescence driven electronics upgrades at the ESO Very Large Telescope (VLT) at the Paranal Observatory.

  9. Applications of Tunable Imaging Filters for the VLT

    CERN Document Server

    Jones, H

    2001-01-01

    Tunable imaging filters have been used for a variety of science programmes on the Anglo-Australian and William Herschel Telescopes during the last five years. This contribution describes these novel devices and reviews the science (both Galactic and extragalactic) done with them. Possible strategies for implementing a tunable filter at the VLT are also discussed. Significant scientific potential exists for a tunable filter on the VLT, particularly in the years before such capability becomes available on 8 -- 10 m-class telescopes elsewhere.

  10. Installation and first results of FLAMES, the VLT multifibre facility

    Science.gov (United States)

    Pasquini, Luca; Alonso, Jaime; Avila, Gerardo; Barriga, Pablo; Biereichel, Peter; Buzzoni, Bernard; Cavadore, Cyril; Cumani, Claudio; Dekker, Hans; Delabre, Bernard; Kaufer, Andreas; Kotzlowski, Heinz; Hill, Vanessa; Lizon, Jean-Luis; Nees, Walter; Santin, Paolo; Schmutzer, Ricardo; Kesteren, A. V.; Zoccali, Manuela

    2003-03-01

    FLAMES is the VLT Fibre Facility, installed and being commissioned at the Nasmyth A of UT2 (Kueyen Telescope). FLAMES has been built and assembled at the VLT telescope in about 4 years through an international collaboration between 10 institutes in 6 countries and 3 continents. It had first light with the fibre link to the red arm of UVES on April 1, and with the GIRAFFE spectrograph on July 3. We have not yet enough data to compare the observed vs. expected astronomical performances, although these first data are encouraging in many respects. We aim at proceeding soon with the remaining tests

  11. MOONS: the Multi-Object Optical and Near-infrared Spectrograph for the VLT

    NARCIS (Netherlands)

    M. Cirasuolo; . et al.; L. Kaper; B. Lemasle

    2014-01-01

    MOONS is a new Multi-Object Optical and Near-infrared Spectrograph selected by ESO as a third generation instrument for the Very Large Telescope (VLT). The grasp of the large collecting area offered by the VLT (8.2m diameter), combined with the large multiplex and wavelength coverage (optical to nea

  12. ESO Council Decides to Continue VLT Project at Paranal

    Science.gov (United States)

    1994-08-01

    to complete negotiation of a Supplementary and Amending Agreement and it was decided that a Council Delegation shall conclude as soon as possible the negotiation of this Agreement. Council noted that the Chilean Delegation has accepted ESO's invitation to hold the final round of negotiations in Europe and proposed that this final round shall be held in the period Sept. 15 - Oct. 15, 1994. Nonetheless, Council also expressed its preoccupation with regard to remaining ambiguities contained in some official statements according to which the formal recognition of ESO's status on Paranal would depend on the conclusion of the above mentioned Agreement. At the May 1994 meetings in Santiago [2], understanding had been reached that this Agreement will merely confirm the already existing legal situation. The main objective is to expand the cooperation between Chile and ESO by granting ensured access for Chilean astronomers to ESO's facilities and incorporate elements of Chilean labour legislation into the ESO internal staff regulations. In view of these circumstances, and pending the successful conclusion of these negotiations, Council therefore instructed the ESO Management to continue exploring alternative sites for the VLT. In a final statement, the ESO Council again expressed its hope that the scientific co-operation between Europe and Chile in the field of astronomy which began in 1963 will continue to develop and expand well into the next century to the mutual benefit of science in both communities. CONTINUATION OF THE VLT PROJECT In practical terms, the above decision by Council implies that ESO will now initiate the steps necessary to move from Europe to Paranal the main mechanical parts of the rotating dome (total weight around 500 tonnes) for the first VLT 8.2-metre unit telescope. It is expected that the sea transport will take place in September-October of this year and that assembly at Paranal will begin soon thereafter, once the concrete base, now under

  13. The design of the MOONS-VLT spectrometer

    NARCIS (Netherlands)

    Oliva, E.; Diolaiti, E.; Garilli, B.; Gratton, R.; Lorenzetti, D.; Schipani, P.; Scuderi, S.; Vanzella, E.; Cirasuolo, M.; Afonso, J.; Bender, R.; Bonifacio, P.; Kaper, L.; Vanzi, L.; Baffa, C.; Bianco, A.; Bonoli, C.; Bortoletto, F.; Bruno, P.; Carbonaro, L.; Centrone, M.; Cresci, G.; De Caprio, V.; Del Vecchio, C.; Di Marcantonio, P.; Di Paola, A.; D'Alessio, F.; D'Alessandro, M.; D'Orsi, S.; Falcini, G.; Ferruzzi, D.; Fontana, A.; Foppiani, I.; Fumana, M.; Giani, E.; Leone, F.; Li Causi, G.; Lombini, M.; Maiolino, R.; Mannucci, F.; Marty, L.; Miglietta, L.; Munari, M.; Navarro, R.; Origlia, L.; Paioro, L.; Pedichini, F.; Pragt, J.; Randich, S.; Scodeggio, M.; Spano, P.; Speziali, R.; Stuik, R.; Tozzi, A.; Vitali, F.

    2012-01-01

    MOONS is a new conceptual design for a multi-object spectrograph for the ESO Very Large Telescope (VLT) which will provide the ESO astronomical community with a powerful, unique instrument able to serve a wide range of Galactic, Extragalactic and Cosmological studies. The instrument foresees 1000

  14. The design of the MOONS-VLT spectrometer

    NARCIS (Netherlands)

    Oliva, E.; Diolaiti, E.; Garilli, B.; Gratton, R.; Lorenzetti, D.; Schipani, P.; Scuderi, S.; Vanzella, E.; Cirasuolo, M.; Afonso, J.; Bender, R.; Bonifacio, P.; Kaper, L.; Vanzi, L.; Baffa, C.; Bianco, A.; Bonoli, C.; Bortoletto, F.; Bruno, P.; Carbonaro, L.; Centrone, M.; Cresci, G.; De Caprio, V.; Del Vecchio, C.; Di Marcantonio, P.; Di Paola, A.; D'Alessio, F.; D'Alessandro, M.; D'Orsi, S.; Falcini, G.; Ferruzzi, D.; Fontana, A.; Foppiani, I.; Fumana, M.; Giani, E.; Leone, F.; Li Causi, G.; Lombini, M.; Maiolino, R.; Mannucci, F.; Marty, L.; Miglietta, L.; Munari, M.; Navarro, R.; Origlia, L.; Paioro, L.; Pedichini, F.; Pragt, J.; Randich, S.; Scodeggio, M.; Spano, P.; Speziali, R.; Stuik, R.; Tozzi, A.; Vitali, F.

    2012-01-01

    MOONS is a new conceptual design for a multi-object spectrograph for the ESO Very Large Telescope (VLT) which will provide the ESO astronomical community with a powerful, unique instrument able to serve a wide range of Galactic, Extragalactic and Cosmological studies. The instrument foresees 1000 fi

  15. Developing an instrument simulator: experience feedback from the JWST/NIRSpec and VLT/MUSE simulators

    Science.gov (United States)

    Jarno, Aurélien; Piqueras, Laure; Bacon, Roland; Ferruit, Pierre; Legros, Emeline; Pécontal-Rousset, Arlette; Gnata, Xavier; Streicher, Ole; Weilbacher, Peter

    2012-09-01

    The Centre de Recherche Astrophysique de Lyon (CRAL) has recently developed two instrument simulators for spectrographic instruments. They are based on Fourier optics, and model the whole chain of acquisition, taking into account both optical aberrations and diffraction effects, by propagating a wavefront through the instrument, according to the Fourier optics concept. One simulates the NIRSpec instrument, a near-infrared multi-object spectrograph for the future James Webb Space Telescope (JWST). The other one models the Multi Unit Spectroscopic Explorer (MUSE) instrument, a second-generation integral-field spectrograph for the Very Large Telescope (VLT). The two simulators have been developed in different contexts (subcontracted versus developed internally), and for very different instruments (space-based versus ground-based), which strengthen the CRAL experience. This paper describes the lessons learned while developing these simulators: development methods, phasing with the project, points to focus on, getting data, interacting with scientists and users, etc.

  16. VIMOS - a Cosmology Machine for the VLT

    Science.gov (United States)

    2002-03-01

    Successful Test Observations With Powerful New Instrument at Paranal [1] Summary One of the most fundamental tasks of modern astrophysics is the study of the evolution of the Universe . This is a daunting undertaking that requires extensive observations of large samples of objects in order to produce reasonably detailed maps of the distribution of galaxies in the Universe and to perform statistical analysis. Much effort is now being put into mapping the relatively nearby space and thereby to learn how the Universe looks today . But to study its evolution, we must compare this with how it looked when it still was young . This is possible, because astronomers can "look back in time" by studying remote objects - the larger their distance, the longer the light we now observe has been underway to us, and the longer is thus the corresponding "look-back time". This may sound easy, but it is not. Very distant objects are very dim and can only be observed with large telescopes. Looking at one object at a time would make such a study extremely time-consuming and, in practical terms, impossible. To do it anyhow, we need the largest possible telescope with a highly specialised, exceedingly sensitive instrument that is able to observe a very large number of (faint) objects in the remote universe simultaneously . The VLT VIsible Multi-Object Spectrograph (VIMOS) is such an instrument. It can obtain many hundreds of spectra of individual galaxies in the shortest possible time; in fact, in one special observing mode, up to 6400 spectra of the galaxies in a remote cluster during a single exposure, augmenting the data gathering power of the telescope by the same proportion. This marvellous science machine has just been installed at the 8.2-m MELIPAL telescope, the third unit of the Very Large Telescope (VLT) at the ESO Paranal Observatory. A main task will be to carry out 3-dimensional mapping of the distant Universe from which we can learn its large-scale structure . "First light

  17. VLT/VLTI Second-Generation Instrumentation: Lessons Learned

    Science.gov (United States)

    Gilmozzi, R.; Pasquini, L.; Russell, A.

    2016-12-01

    The five second-generation instruments already delivered for the Very Large Telescope (VLT) represent worthy successors to the first generation of instrumentation development. Despite this success, it is still possible to learn many lessons for the future. A review, preceded by a workshop, on the lessons learned from the second-generation instrumentation for the VLT and VLT Interferometer took place in November 2015, following a previous review twelve years ago on lessons learned from the first-generation instruments. The aim of the workshop was to identify lessons in order to help define/refine good practice and make recommendations for the future. This article briefly reports on the workshop and summarises the findings of the review panel, their recommendations and some of the steps to implement them.

  18. ESPRESSO instrument control electronics: a PLC based distributed layout for a second generation instrument at ESO VLT

    Science.gov (United States)

    Baldini, V.; Cirami, R.; Coretti, I.; Cristiani, S.; Di Marcantonio, P.; Mannetta, M.; Santin, P.; Mégevand, D.; Zerbi, F.

    2014-07-01

    ESPRESSO is an ultra-stable fiber-fed spectrograph designed to combine incoherently the light coming from up to 4 Unit Telescopes of the ESO VLT. From the Nasmyth focus of each telescope the light, through an optical path, is fed by the Coudé Train subsystems to the Front End Unit placed in the Combined Coudé Laboratory. The Front End is composed by one arm for each telescope and its task is to convey the incoming light, after a calibration process, into the spectrograph fibers. To perform these operations a large number of functions are foreseen, like motorized stages, lamps, digital and analog sensors that, coupled with dedicated Technical CCDs (two per arms), allow to stabilize the incoming beam up to the level needed to exploit the ESPRESSO scientific requirements. The Instrument Control Electronics goal is to properly control all the functions in the Combined Coudé Laboratory and the spectrograph itself. It is fully based on a distributed PLC architecture, abandoning in this way the VME-based technology previously adopted for the ESO VLT instruments. In this paper we will describe the ESPRESSO Instrument Control Electronics architecture, focusing on the distributed layout and its interfaces with the other ESPRESSO subsystems.

  19. Sharpest Ever VLT Images at NAOS-CONICA "First Light"

    Science.gov (United States)

    2001-12-01

    Very Promising Start-Up of New Adaptive Optics Instrument at Paranal Summary A team of astronomers and engineers from French and German research institutes and ESO at the Paranal Observatory is celebrating the successful accomplishment of "First Light" for the NAOS-CONICA Adaptive Optics facility . With this event, another important milestone for the Very Large Telescope (VLT) project has been passed. Normally, the achievable image sharpness of a ground-based telescope is limited by the effect of atmospheric turbulence. However, with the Adaptive Optics (AO) technique, this drawback can be overcome and the telescope produces images that are at the theoretical limit, i.e., as sharp as if it were in space . Adaptive Optics works by means of a computer-controlled, flexible mirror that counteracts the image distortion induced by atmospheric turbulence in real time. The larger the main mirror of the telescope is, and the shorter the wavelength of the observed light, the sharper will be the images recorded. During a preceding four-week period of hard and concentrated work, the expert team assembled and installed this major astronomical instrument at the 8.2-m VLT YEPUN Unit Telescope (UT4). On November 25, 2001, following careful adjustments of this complex apparatus, a steady stream of photons from a southern star bounced off the computer-controlled deformable mirror inside NAOS and proceeded to form in CONICA the sharpest image produced so far by one of the VLT telescopes. With a core angular diameter of only 0.07 arcsec, this image is near the theoretical limit possible for a telescope of this size and at the infrared wavelength used for this demonstration (the K-band at 2.2 µm). Subsequent tests reached the spectacular performance of 0.04 arcsec in the J-band (wavelength 1.2 µm). "I am proud of this impressive achievement", says ESO Director General Catherine Cesarsky. "It shows the true potential of European science and technology and it provides a fine

  20. The Four-Laser Guide Star Facility (4LGSF) for the ESO VLT Adaptive Optics Facility (AOF)

    Science.gov (United States)

    Hackenberg, W.; Bonaccini Calia, D.; Lewis, S.; Holzlohner, R.; Buzzoni, B.; Comin, M.; Dupuy, C.; Guidolin, I. M.; Kern, L.; Quattri, M.; Quentin, J.; Ridings, R.; Argomedo, J.; Arsenault, R.; Conzelmann, R.; Delabre, B.; Donaldson, R.; Downing, M.; Duchateau, M.; Hubin, N.; Igl, G.; Jochum, L.; Jolley, P.; Jost, A.; Kiekebusch, M.; Kolb, J.; Kuntschner, H.; Lizon, J.-L.; Le Louarn, M.; Madec, P.-Y.; Manescau, A.; Paufique, J.; Pirard, J.-F.; Reyes, J.; Silber, A.; Soenke, C.; Stroebele, S.; Stuik, R.; Tordo, S.; Vernet, E.; Collazos, R. Guzman

    2011-09-01

    The 4LGSF is to be installed as a subsystem of the ESO Adaptive Optics Facility (AOF) on Unit Telescope 4 (UT4) of the VLT, to provide the AO systems GALACSI/MUSE and GRAAL/HAWK-I with four sodium laser guide stars. The 4LGSF will deploy four modular LGS Units at the UT4 Centrepiece. Two key aspects of the 4LGSF design are: (i) new industrial laser source (fibre lasers) with reduced volume, reduced need of maintenance, higher reliability, simpler operation and optimised spectral format for highly efficient sodium excitation, (ii) modular structure of the four LGS Units, composed of the laser and laser launch telescope, capable to operate independently of the others. The final design of the 4LGSF is now complete and the project has entered the manufacturing, assembly, integration and test phase. Furthermore, modular LGS units containing the laser emitter integrated on the launch telescope have already been demonstrated at ESO in the past years, and results will be presented. We believe that having the laser sources as an integral part of a modular unit together with the launching system offers many advantages at the system level, including the avoidance of beam relays, retaining the flexibility to use as many LGS as required independently, and the possibility of building redundancy into the system. We believe that many of these 4LGSF concepts can serve for ELT multi-LGS-assisted adaptive telescope designs and provide a valuable experience in advance of the E-ELT.

  1. Assembly and test results of the AOF laser guide star units at ESO

    Science.gov (United States)

    Hackenberg, W.; Bonaccini Calia, D.; Buzzoni, B.; Comin, M.; Dupuy, C.; Gago, F.; Guidolin, I. M.; Guzman, R.; Holzloehner, R.; Kern, L.; Kirchbauer, J.-.; Lewis, S.; Lizon, J.-.; McLay, S.; Pfrommer, T.; Quattri, M.; Quentin, J.; Ridings, R.

    2014-08-01

    The Four Laser Guide Star Facility (4LGSF) is part of the ESO Adaptive Optics Facility, in which one of the VLT telescopes, UT4, is transformed in an adaptive telescope-equipped with a deformable secondary mirror, two adaptive optics systems at the Nasmyth focii and four sodium laser guide star modular units. In this paper we present the design, the assembly and validation test performed so far in Europe on the first laser guide star unit.

  2. "First Light" for the VLT Interferometer

    Science.gov (United States)

    2001-03-01

    Excellent Fringes From Bright Stars Prove VLTI Concept Summary Following the "First Light" for the fourth of the 8.2-m telescopes of the VLT Observatory on Paranal in September 2000, ESO scientists and engineers have just successfully accomplished the next major step of this large project. On March 17, 2001, "First Fringes" were obtained with the VLT Interferometer (VLTI) - this important event corresponds to the "First Light" for an astronomical telescope. At the VLTI, it occurred when the infrared light from the bright star Sirius was captured by two small telescopes and the two beams were successfully combined in the subterranean Interferometric Laboratory to form the typical pattern of dark and bright lines known as " interferometric fringes ". This proves the success of the robust VLTI concept, in particular of the "Delay Line". On the next night, the VLTI was used to perform a scientific measurement of the angular diameter of another comparatively bright star, Alpha Hydrae ( Alphard ); it was found to be 0.00929±0.00017 arcsec . This corresponds to the angular distance between the two headlights of a car as seen from a distance of approx. 35,000 kilometres. The excellent result was obtained during a series of observations, each lasting 2 minutes, and fully confirming the impressive predicted abilities of the VLTI . This first observation with the VLTI is a monumental technological achievement, especially in terms of accuracy and stability . It crucially depends on the proper combination and functioning of a large number of individual opto-mechnical and electronic elements. This includes the test telescopes that capture the starlight, continuous and extremely precise adjustment of the various mirrors that deflect the light beams as well as the automatic positioning and motion of the Delay Line carriages and, not least, the optimal tuning of the VLT INterferometer Commissionning Instrument (VINCI). These initial observations prove the overall concept for the

  3. VLT Instruments Pipeline System Overview

    Science.gov (United States)

    Jung, Y.; Ballester, P.; Banse, K.; Hummel, W.; Izzo, C.; McKay, D. J.; Kiesgen, M.; Lundin, L. K.; Modigliani, A.; Palsa, R. M.; Sabet, C.

    2004-07-01

    Since the beginning of the VLT operations in 1998, substantial effort has been put in the development of automatic data reduction tools for the VLT instruments. A VLT instrument pipeline is a complex system that has to be able to identify and classify each produced FITS file, optionally retrieve calibration files from a database, use an image processing software to reduce the data, compute and log quality control parameters, produce FITS images or tables with the correct headers, optionally display them in the control room and send them to the archive. Each instrument has its own dedicated pipeline, based on a common infrastructure and installed with the VLT Data Flow System (DFS). With the increase in the number and the complexity of supported instruments and in the rate of produced data, these pipelines are becoming vital for both the VLT operations and the users, and request more and more resources for development and maintenance. This paper describes the different pipeline tasks with some real examples. It also explains how the development process has been improved to both decrease its cost and increase the pipelines quality using the lessons learned from the first instruments pipelines development.

  4. Validation Through Simulations of a Cn2 Profiler for the ESO/VLT Adaptive Optics Facility

    CERN Document Server

    Garcia-Rissmann, A; Kolb, J; Louarn, M Le; Madec, P -Y; Neichel, B

    2015-01-01

    The Adaptive Optics Facility (AOF) project envisages transforming one of the VLT units into an adaptive telescope and providing its ESO (European Southern Observatory) second generation instruments with turbulence corrected wavefronts. For MUSE and HAWK-I this correction will be achieved through the GALACSI and GRAAL AO modules working in conjunction with a 1170 actuators Deformable Secondary Mirror (DSM) and the new Laser Guide Star Facility (4LGSF). Multiple wavefront sensors will enable GLAO and LTAO capabilities, whose performance can greatly benefit from a knowledge about the stratification of the turbulence in the atmosphere. This work, totally based on end-to-end simulations, describes the validation tests conducted on a Cn2 profiler adapted for the AOF specifications. Because an absolute profile calibration is strongly dependent on a reliable knowledge of turbulence parameters r0 and L0, the tests presented here refer only to normalized output profiles. Uncertainties in the input parameters inherent t...

  5. VLT Captures First Direct Spectrum of an Exoplanet

    Science.gov (United States)

    2010-01-01

    eclipse", and then the spectrum could be extracted by comparing the light of the star before and after. However, this method can only be applied if the orientation of the exoplanet's orbit is exactly right, which is true for only a small fraction of all exoplanetary systems. The present spectrum, on the other hand, was obtained from the ground, using ESO's Very Large Telescope (VLT), in direct observations that do not depend on the orbit's orientation. As the host star is several thousand times brighter than the planet, this is a remarkable achievement. "It's like trying to see what a candle is made of, by observing it from a distance of two kilometres when it's next to a blindingly bright 300 Watt lamp," says Janson. The discovery was made possible by the infrared instrument NACO, mounted on the VLT, and relied heavily on the extraordinary capabilities of the instrument's adaptive optics system [3]. Even more precise images and spectra of giant exoplanets are expected both from the next generation instrument SPHERE, to be installed on the VLT in 2011, and from the European Extremely Large Telescope. The newly collected data show that the atmosphere enclosing the planet is still poorly understood. "The features observed in the spectrum are not compatible with current theoretical models," explains co-author Wolfgang Brandner. "We need to take into account a more detailed description of the atmospheric dust clouds, or accept that the atmosphere has a different chemical composition from that previously assumed." The astronomers hope to soon get their hands on the fingerprints of the other two giant planets so they can compare, for the first time, the spectra of three planets belonging to the same system. "This will surely shed new light on the processes that lead to the formation of planetary systems like our own," concludes Janson. Notes [1] As every rainbow demonstrates, white light can be split up into different colours. Astronomers artificially split up the light they

  6. United Kingdom Infrared Telescope's Spectrograph Observations of Human-Made Space Objects

    Science.gov (United States)

    Buckalew, Brent; Abercromby, Kira; Lederer, Susan; Frith, James; Cowardin, Heather

    2017-01-01

    Presented here are the results of the United Kingdom Infrared Telescope (UKIRT) spectral observations of human-made space objects taken from 2014 to 2015. The data collected using the UIST infrared spectrograph cover the wavelength range 0.7-2.5 micrometers. Overall, data were collected on 18 different orbiting objects at or near the geosynchronous (GEO) regime. Thirteen of the objects are spacecraft, one is a rocket body, and four are cataloged as debris pieces. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials; thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared by focusing on features from hydrocarbons and silicon. The spacecraft show distinct features due to the presence of solar panels. Signature variations between rocket bodies, due to the presence of various metals and paints on their surfaces, show a clear distinction from those objects with solar panels, demonstrating that one can distinguish most spacecraft from rocket bodies through infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give excellent indications as to the nature of the surface materials on the objects. Further telescopic data collection and model updates to include more materials, noise, surface roughness, and material degradation are necessary to make better assessments of orbital object material types. A comparison conducted between objects observed previously with the NASA Infrared Telescope Facility (IRTF) shows similar materials and trends from the two telescopes and from the two distinct data sets. However, based on the current state of the model, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft, rocket bodies, or debris.

  7. United Kingdom Infrared Telescope's Spectrograph Observations of Human-Made Space Objects

    Science.gov (United States)

    Buckalew, Brent; Abercromby, Kira; Lederer, Susan; Cowardin, Heather; Frith, James

    2017-01-01

    Presented here are the results of the United Kingdom Infrared Telescope (UKIRT) spectral observations of human-made space objects taken from 2014 to 2015. The data collected using the UKIRT 1-5 micron Imager Spectrometer (UIST) cover the wavelength range 0.7-2.5 micrometers. Overall, data were collected on 18 different orbiting objects at or near geosynchronous orbit (GEO). Two of the objects are controlled spacecraft, twelve are non-controlled spacecraft, one is a rocket body, and three are cataloged as debris. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials; thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared by focusing on features from hydrocarbons and silicon. The spacecraft, both the controlled and non-controlled, show distinct features due to the presence of solar panels whereas the rocket bodies do not. Signature variations between rocket bodies, due to the presence of various metals and paints on their surfaces, show a clear distinction from those objects with solar panels, demonstrating that one can distinguish most spacecraft from rocket bodies through infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give well-correlated indications as to the nature of the surface materials on the objects. Further telescopic data collection and model updates to include noise, surface roughness, and material degradation are necessary to make better assessments of orbital object material types. A comparison conducted between objects observed previously with the NASA Infrared Telescope Facility (IRTF) shows similar materials and trends from the two telescopes and different times. However, based on the current state of the model, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft

  8. Calibration strategy of the pyramid wavefront sensor module of ERIS with the VLT deformable secondary mirror

    Science.gov (United States)

    Riccardi, A.; Briguglio, R.; Pinna, E.; Agapito, G.; Quiros-Pacheco, F.; Esposito, S.

    2012-07-01

    ERIS is a new Adaptive Optics Instrument for the Adaptive Optics Facility of the VLT that foresees, in its design phase, a Pyramid Wavefront Sensor Module (PWM) to be used with the VLT Deformable Secondary Mirror (VLT-DSM) as corrector. As opposite to the concave secondary mirrors currently in use (e.g. at LBT), VLT-DSM is convex and calibration of the interaction matrix (IM) between the PWM and the DSM is not foreseen on-telescope during day-time. In this paper different options of calibration are evaluated and compared with particular attention on the synthetic evaluation and on-sky calibration of the IM. A trade-off of the calibration options, the optimization techniques and the related validation with numerical simulations are also provided.

  9. The VLT observations of the HDF-S NICMOS field photometric catalog and high redshift galaxy candidates

    CERN Document Server

    Fontana, A; Fosbury, R A E; Giallongo, E; Hook, R N; Poli, F; Renzini, A; Rosati, P; Viezzer, R

    1999-01-01

    We present the deep UBVRI observations of the HDF-S NICMOS field obtained as part of the Science Verification of the VLT Unit 1 telescope. The images have been used to construct object catalogs and to obtain photometric redshifts. The effective field of view is $\\simeq 70\\times70$ arcsec$^2$, and the formal $5\\sigma$ limiting magnitudes (in a 2 FWHM aperture) are 26.3, 27.8, 27.5, 26.9, 25.2 in the $U$, $B$, $V$, $R$ and $I$ bands, respectively. Thanks to the sub-arcsecond image quality, relatively long exposure time, and large collecting area of the VLT, this is the deepest set of multicolor images ever obtained from a ground-based telescope. Galaxy counts have been derived independently in each band, and show no significant departures from previous data from wider areas. A multicolor photometric catalog of all the galaxies selected in the $R$ band has also been obtained and used to derive photometric redshifts for all galaxies with $R \\leq 26.5 $, using also the J,H and K magnitudes from the NICMOS deep obs...

  10. The VLT FLAMES Tarantula Survey

    NARCIS (Netherlands)

    Evans, C.; Taylor, W.; Sana, H.; Hénault-Brunet, V.; Bagnoli, T.; Bastian, N.; Bestenlehner, J.; Bonanos, A.; Bressert, E.; Brott, I.; Campbell, M.; Cantiello, M.; Carraro, G.; Clark, S.; Costa, E.; Crowther, P.; de Koter, A.; de Mink, S.; Doran, E.; Dufton, P.; Dunstall, P.; Garcia, M.; Gieles, M.; Gräfener, G.; Herrero, A.; Howarth, I.; Izzard, R.; Köhler, K.; Langer, N.; Lennon, D.; Maíz Apellániz, J.; Markova, N.; Najarro, P.; Puls, J.; Ramirez, O.; Sabín-Sanjulián, C.; Simón-Díaz, S.; Smartt, S.; Stroud, V.; van Loon, J.; Vink, J.S.; Walborn, N.

    2011-01-01

    We introduce the VLT FLAMES Tarantula Survey, an ESO Large Programme from which we have obtained optical spectroscopy of over 800 massive stars in the spectacular 30 Doradus region of the Large Magellanic Cloud. A key feature is the use of multi-epoch observations to provide strong constraints on

  11. New Vistas Open with MIDI at the VLT Interferometer

    Science.gov (United States)

    2002-12-01

    "First Fringes" in Mid-Infrared Spectral Region with Two Giant Telescopes Summary Following several weeks of around-the-clock work, a team of astronomers and engineers from Germany, the Netherlands, France and ESO [2] has successfully performed the first observations with the MID-Infrared interferometric instrument (MIDI), a new, extremely powerful instrument just installed in the underground laboratory of the VLT Interferometer (VLTI) at the Paranal Observatory (Chile). In the early morning of December 15, 2002, two of the 8.2 m VLT unit telescopes (ANTU and MELIPAL) were pointed towards the southern star eta Carinae and the two light beams were directed via the complex intervening optics system towards MIDI. After a few hours of tuning and optimization, strong and stable interferometric fringes were obtained, indicating that all VLTI components - from telescopes to the new instrument - were working together perfectly. Two more stars were observed before sunrise, further proving the stability of the entire system. The first observations with MIDI mark one more important step towards full and regular operation of the VLT Interferometer [3] . They are a result of five years of determined efforts within a concerted technology project, based on a close collaboration between ESO and several European research institutes (see below). Now opening great research vistas, they also represent several "firsts" in observational astrophysics, together amounting to a real breakthrough in the field of astronomical interferometry . New views at mid-infrared wavelengths : MIDI is sensitive to light of a wavelength near 10 µm, i.e., in the mid-infrared spectral region ("thermal infrared"). This provides rich opportunities to study a wide range of otherwise inaccessible, crucial astrophysical phenomena, e.g., the formation of planets in dusty disks around newborn stars and the innermost regions around black holes. However, it is a great technical challenge to perform mid

  12. The design of ERIS for the VLT

    Science.gov (United States)

    Amico, P.; Marchetti, E.; Pedichini, F.; Baruffolo, A.; Delabre, B.; Duchateau, M.; Ekinci, M.; Fantinel, D.; Fedrigo, E.; Finger, G.; Frank, C.; Hofmann, R.; Jolley, P.; Lizon, J. L.; Le Louarn, M.; Madec, P.-Y.; Soenke, C.; Weisz, H.

    2012-09-01

    The Enhanced Resolution Imager and Spectrograph (ERIS) is the next-generation instrument planned for the Very Large Telescope (VLT) and the Adaptive Optics Facility (AOF)1. It is an AO assisted instrument that will make use of the Deformable Secondary Mirror and the new Laser Guide Star Facility (4LGSF), and it is designed for the Cassegrain focus of the telescope UT4. The project just concluded its conceptual design phase and is awaiting formal approval to continue to the next phase. ERIS will offer 1-5 μm imaging and 1-2.5 μm integral field spectroscopic capabilities with high Strehl performance. As such it will replace, with much improved single conjugated AO correction, the most scientifically important and popular observing capabilities currently offered by NACO2 (diffraction limited imaging in JM band, Sparse Aperture Masking and APP coronagraphy) and by SINFONI3, whose instrumental module, SPIFFI, will be re-used in ERIS. The Cassegrain location and the performance requirements impose challenging demands on the project, from opto-mechanical design to cryogenics to the operational concept. In this paper we describe the baseline design proposed for ERIS and discuss these technical challenges, with particular emphasis on the trade-offs and the novel solutions proposed for building ERIS.

  13. VST telescope dynamic analisys and position control algorithms

    CERN Document Server

    Schipani, P

    2001-01-01

    The VST (VLT Survey Telescope) is a 2.6 m class Alt-Az telescope to be installed on Cerro Paranal in the Atacama desert, Northern Chile, in the European Southern Observatory (ESO) site. The VST is a wide-field imaging facility planned to supply databases for the ESO Very Large Telescope (VLT) science and carry out stand-alone observations in the UV to I spectral range. So far no telescope has been dedicated entirely to surveys; the VST will be the first survey telescope to start the operation, as a powerful survey facility for the VLT observatory. This paper will focus on the axes motion control system. The dynamic model of the telescope will be analyzed, as well as the effect of the wind disturbance on the telescope performance. Some algorithms for the telescope position control will be briefly discussed.

  14. The Cepheid Distance to NGC 5236 (M 83) with the VLT

    NARCIS (Netherlands)

    Thim, F.; Tammann, G. A.; Saha, A.; Dolphin, A.; Sandage, A.; Tolstoy, E.; Labhardt, L.

    2003-01-01

    Published in: Astrophys. J. 590 (2003) 256-270 citations recorded in [Science Citation Index] Abstract: Cepheids have been observed in NGC 5236 (M 83) using the ANTU (UT1) 8.2 meter telescope of the ESO VLT with FORS1. Observations over 34 epochs in V and I have been made between January 2000 and Ju

  15. The VLT LBG Redshift Survey - I. Clustering and dynamics of ≈1000 galaxies at z≈ 3

    NARCIS (Netherlands)

    Bielby, R. M.; Shanks, T.; Weilbacher, P. M.; Infante, L.; Crighton, N. H. M.; Bornancini, C.; Bouché, N.; Héraudeau, P.; Lambas, D. G.; Lowenthal, J.; Minniti, D.; Padilla, N.; Petitjean, P.; Theuns, T.

    2011-01-01

    We present the initial imaging and spectroscopic data acquired as part of the Very Large Telescope (VLT) VIMOS Lyman-break galaxy Survey. UBR (or UBVI) imaging covers five ≈36 × 36 arcmin2 fields centred on bright z > 3 quasi-stellar objects (QSOs), allowing ≈21 000 2

  16. MOONS: a multi-object optical and near-infrared spectrograph for the VLT

    NARCIS (Netherlands)

    Cirasuolo, M.; Afonso, J.; Bender, R.; Bonifacio, P.; Evans, C.; Kaper, L.; Oliva, Ernesto; Vanzi, Leonardo; Abreu, Manuel; Atad-Ettedgui, Eli; Babusiaux, Carine; Bauer, Franz E.; Best, Philip; Bezawada, Naidu; Bryson, Ian R.; Cabral, Alexandre; Caputi, Karina; Centrone, Mauro; Chemla, Fanny; Cimatti, Andrea; Cioni, Maria-Rosa; Clementini, Gisella; Coelho, João.; Daddi, Emanuele; Dunlop, James S.; Feltzing, Sofia; Ferguson, Annette; Flores, Hector; Fontana, Adriano; Fynbo, Johan; Garilli, Bianca; Glauser, Adrian M.; Guinouard, Isabelle; Hammer, Jean-François; Hastings, Peter R.; Hess, Hans-Joachim; Ivison, Rob J.; Jagourel, Pascal; Jarvis, Matt; Kauffman, G.; Lawrence, A.; Lee, D.; Li Causi, G.; Lilly, S.; Lorenzetti, D.; Maiolino, R.; Mannucci, F.; McLure, R.; Minniti, D.; Montgomery, D.; Muschielok, B.; Nandra, K.; Navarro, R.; Norberg, P.; Origlia, L.; Padilla, N.; Peacock, J.; Pedicini, F.; Pentericci, L.; Pragt, J.; Puech, M.; Randich, S.; Renzini, A.; Ryde, N.; Rodrigues, M.; Royer, F.; Saglia, R.; Sánchez, A.; Schnetler, H.; Sobral, D.; Speziali, R.; Todd, S.; Tolstoy, E.; Torres, M.; Venema, L.; Vitali, F.; Wegner, M.; Wells, M.; Wild, V.; Wright, G.

    2012-01-01

    MOONS is a new conceptual design for a Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope (VLT), selected by ESO for a Phase A study. The baseline design consists of ~1000 fibers deployable over a field of view of ~500 square arcmin, the largest patrol field offered by

  17. VIMOS-VLT and Spitzer observations of a radio galaxy at z=2.5

    NARCIS (Netherlands)

    Villar-Martin, M; Sanchez, SF; De Breuck, C; Peletier, R; Vernet, J; Rettura, A; Seymour, N; Humphrey, A; Stern, D; Alighieri, SD; Fosbury, R

    2006-01-01

    We present: (i) a kinematic and morphological study of the giant Ly alpha nebula associated with the radio galaxy MRC 2104-242 (z = 2.49) based on integral field spectroscopic Visible Multiobject Spectrograph (VIMOS) data from the Very Large Telescope (VLT), and (ii) a photometric study of the host

  18. VLT/NACO observations of Neptune's ring arcs

    Science.gov (United States)

    Renner, S.; Sicardy, B.; Souami, D.; Dumas, C.

    2011-10-01

    We present NACO adaptative optics observations of Neptune's ring arcs at 2.2 μm (K band), taken with the VLT-Yepun telescope in August 2007. We give improved mean motion values for the arcs and Galatea, thus confirming the mismatch between the arcs' position and the location of the 42:43 corotation inclination resonance. We compare the photometry of the arcs with previous observations. We finally use the data to constrain the masses and positions of the coorbital satellites which could confine the arcs, while allowing a slow evolution of the system.

  19. Spectral analysis of Uranus' 2014 bright storm with VLT/SINFONI

    CERN Document Server

    Irwin, Patrick G J; Read, Peter L; Tice, Dane; de Pater, Imke; Orton, Glenn S; Teanby, Nicholas A; Davis, Gary R

    2015-01-01

    An extremely bright storm system observed in Uranus' atmosphere by amateur observers in September 2014 triggered an international campaign to observe this feature with many telescopes across the world. Observations of the storm system in the near infrared were acquired in October and November 2014 with SINFONI on ESO's Very Large Telescope (VLT) in Chile. SINFONI is an Integral Field Unit spectrometer returning 64x64 pixel images with 2048 wavelengths. Image cubes in the H-band (1.43 - 1.87 microns) were obtained at spatial resolutions of ~0.1". The observations show that the centre of the storm feature shifts markedly with increasing altitude, moving in the retrograde direction and slightly poleward with increasing altitude. We also see a faint 'tail' of more reflective material to the immediate south of the storm, which again trails in the retrograde direction. The observed spectra were analysed with the radiative transfer and retrieval code, NEMESIS. We find that the storm is well-modelled using either two...

  20. VLT imaging of the β Pictoris gas disk

    Science.gov (United States)

    Nilsson, R.; Brandeker, A.; Olofsson, G.; Fathi, K.; Thébault, Ph.; Liseau, R.

    2012-08-01

    Context. Circumstellar debris disks older than a few Myr should be largely devoid of primordial gas remaining from the protoplanetary disk phase. Tracing the origin of observed atomic gas in Keplerian rotation in the edge-on debris disk surrounding the ~12 Myr old star β Pictoris requires more detailed information about its spatial distribution than has previously been acquired by limited slit spectroscopy. Especially indications of asymmetries and presence of Ca ii gas at high disk latitudes call for additional investigation to exclude or confirm its connection to observed dust structures or suggested cometary bodies on inclined eccentric orbits. Aims: We set out to recover a complete image of the Fe i and Ca ii gas emission around β Pic by spatially resolved, high-resolution spectroscopic observations to better understand the morphology and origin of the gaseous disk component. Methods: The multiple fiber facility FLAMES/GIRAFFE at the Very Large Telescope (VLT), with the large integral-field-unit ARGUS, was used to obtain spatially resolved optical spectra (from 385.9 to 404.8 nm) in four regions covering the northeast and southwest side of the disk. Emission lines from Fe i (at 386.0 nm) and Ca ii (at 393.4 and 396.8 nm) were mapped and could be used to fit a parametric function for the disk gas distribution, using a gas-ionisation code for gas-poor debris disks. Results: Both Fe i and Ca ii emission are clearly detected, with the former dominating along the disk midplane, and the latter revealing vertically more extended gas. The surface intensity of the Fe i emission is lower but more extended in the northeast (reaching the 210 AU limit of our observations) than in the southwest, while Ca ii shows the opposite asymmetry. The modelled Fe gas disk profile shows a linear increase in scale height with radius, and a vertical profile that suggests dynamical interaction with the dust. We also qualitatively demonstrate that the Ca ii emission profile can be

  1. The VLT Real Time Display

    Science.gov (United States)

    Herlin, T.; Brighton, A.; Biereichel, P.

    The VLT Real-Time Display (RTD) software was developed in order to support image display in real-time, providing a tool for users to display video like images from a camera or detector as fast as possible on an X-Server. The RTD software is implemented as a package providing a Tcl/Tk image widget written in C++ and an independent image handling library and can be used as a building block, adding display capabilities to dedicated VLT control applications. The RTD widget provides basic image display functionality like: panning, zooming, color scaling, colormaps, intensity changes, pixel query, overlaying of line graphics. A large set of assisting widgets, e.g., colorbar, zoom window, spectrum plot are provided to enable the building of image applications. The support for real-time is provided by an RTD image event mechanism used for camera or detector subsystems to pass images to the RTD widget. Image data are passed efficiently via shared memory. This paper describes the architecture of the RTD software and summarizes the features provided by RTD.

  2. KOALA, a wide-field 1000 element integral-field unit for the Anglo-Australian Telescope: assembly and commissioning

    Science.gov (United States)

    Zhelem, Ross; Brzeski, Jurek; Case, Scott; Churilov, Vladimir; Ellis, Simon; Farrell, Tony; Green, Andrew; Heng, Anthony; Horton, Anthony; Ireland, Michael; Jones, Damien; Klauser, Urs; Lawrence, Jon; Miziarski, Stan; Orr, David; Pai, Naveen; Staszak, Nick; Tims, Julia; Vuong, Minh; Waller, Lew; Xavier, Pascal

    2014-07-01

    The KOALA optical fibre feed for the AAOmega spectrograph has been commissioned at the Anglo-Australian Telescope. The instrument samples the reimaged telescope focal plane at two scales: 1.23 arcsec and 0.70 arcsec per image slicing hexagonal lenslet over a 49x27 and 28x15 arcsec field of view respectively. The integral field unit consists of 2D hexagonal and circular lenslet arrays coupling light into 1000 fibres with 100 micron core diameter. The fibre run is over 35m long connecting the telescope Cassegrain focus with the bench mounted spectrograph room where all fibres are reformatted into a one-dimensional slit. Design and assembly of the KOALA components, engineering challenges encountered, and commissioning results are discussed.

  3. Observations of Lick Standard Stars Using the SCORPIO Multi-Slit Unit at the SAO 6-m Telescope

    CERN Document Server

    Sharina, M E; Puzia, T

    2006-01-01

    We present Lick line-index measurements of standard stars from the list of Worthey. The spectra were taken with the multi-slit unit of the SCORPIO spectrograph at the 6-m Special Astrophysical observatory telescope. We describe in detail our method of analysis and explain the importance of using the Lick index system for studying extragalactic globular clusters. Our results show that the calibration of our instrumental system to the standard Lick system can be performed with high confidence.

  4. Final acceptance of the 200 GHz telescope unit for the QUIJOTE CMB experiment

    Science.gov (United States)

    Sanquirce-García, R.; Sainz-Pardo, I.; Etxeita-Arriaga, B.; Murga-Llano, Gaizka; Fernandez-Santos, E.; Sánchez-de-la-Rosa, V.; Viera-Curbelo, T. A.; Gómez-Reñasco, F.; Aguiar-González, M.; Pérez de Taoro, M. R.; Rubiño-Martín, J. A.

    2016-07-01

    The QUIJOTE (Q-U-I JOint TEnerife) experiment is a scientific collaboration, led by the Instituto de Astrofísica de Canarias (IAC), with the aim of measuring the polarization of the Cosmic Microwave Background (CMB) in the frequency range 10-40 GHz and at large angular scales (around 1°). The project is composed of 2 telescopes and 3 instruments, located in Teide Observatory (Tenerife, Spain). Idoḿs contribution for this project is divided in two phases. Phase I consisted on the design, assembly and factory testing of the first telescope (2008), the integration and functional tests for the 5 polarimeters of the first instrument (2009), and the design and construction supervision of the building which protects both telescopes (2009), including the installation and commissioning of the mechanism for domes apertures. Phase II comprised the design, factory assembly and testing, transport and final commissioning on site of the second telescope, which finished in January 2015. The optical design of both telescopes should allow them to reach up to 200 GHz. The required opto-mechanical performance was checked under nominal conditions, reaching a pointing and tracking accuracy lower than 5 arcsec in both axes, 8 times better than specified. Particular inspections and tests were carried out for critical systems, as the rotary joint that transmits fluid, power and signal to the rotary elements, or for the safety system to ensure personnel and hardware protection under emergency conditions. This paper contains a comprehensive description of the power electronics and acquisition/control design required for safely operation under nominal and emergency conditions, as well as a detailed description of the factory and observatory tests required for the final acceptance of the telescope

  5. The VLT LBG Redshift Survey - I. Clustering and dynamics of approximate to 1000 galaxies at z approximate to 3

    NARCIS (Netherlands)

    Bielby, R. M.; Shanks, T.; Weilbacher, P. M.; Infante, L.; Crighton, N. H. M.; Bornancini, C.; Bouche, N.; Heraudeau, P.; Lambas, D. G.; Lowenthal, J.; Minniti, D.; Padilla, N.; Petitjean, P.; Theuns, T.

    2011-01-01

    We present the initial imaging and spectroscopic data acquired as part of the Very Large Telescope (VLT) VIMOS Lyman-break galaxy Survey. UBR (or UBVI) imaging covers five approximate to 36 x 36 arcmin(2) fields centred on bright z > 3 quasi-stellar objects (QSOs), allowing approximate to 21 000 2 <

  6. AVES: an adaptive optics visual echelle spectrograph for the VLT

    Science.gov (United States)

    Pasquini, Luca; Delabre, Bernard; Avila, Gerardo; Bonaccini, Domenico

    1998-07-01

    We present the preliminary study of a low cost, high performance spectrograph for the VLT, for observations in the V, R and I bands. This spectrograph is meant for intermediate (R equals 16,000) resolution spectroscopy of faint (sky and/or detector limited) sources, with particular emphasis on the study of solar-type (F-G) stars belonging to the nearest galaxies and to distant (or highly reddened) galactic clusters. The spectrograph is designed to use the adaptive optics (AO) systems at the VLT Telescope. Even if these AO systems will not provide diffraction limited images in the V, R and I bands, the photon concentration will still be above approximately 60% of the flux in an 0.3 arcsecond aperture for typical Paranal conditions. This makes the construction of a compact, cheap and efficient echelle spectrograph possible. AVES will outperform comparable non adaptive optic instruments by more than one magnitude for sky- and/or detector-limited observations, and it will be very suitable for observations in crowded fields.

  7. VLTI First Fringes with Two Auxiliary Telescopes at Paranal

    Science.gov (United States)

    2005-03-01

    ESO Video Newsreel 15, released on March 14, 2005. It provides an introduction to the VLT Interferometer (VLTI) and the two Auxiliary Telescopes (ATs) now installed at Paranal. ESO PR Photo 07a/05 shows the impressive ensemble at the summit of Paranal. From left to right, the enclosure of VLT Antu, Kueyen and Melipal, AT1, the VLT Survey Telescope (VST) in the background, AT2 and VLT Yepun. Located at the summit of the 2,600-m high Cerro Paranal in the Atacama Desert (Chile), ESO's Very Large Telescope (VLT) is at the forefront of astronomical technology and is one of the premier facilities in the world for optical and near-infrared observations. The VLT is composed of four 8.2-m Unit Telescope (Antu, Kueyen, Melipal and Yepun). They have been progressively put into service together with a vast suite of the most advanced astronomical instruments and are operated every night in the year. Contrary to other large astronomical telescopes, the VLT was designed from the beginning with the use of interferometry as a major goal. The href="/instruments/vlti">VLT Interferometer (VLTI) combines starlight captured by two 8.2- VLT Unit Telescopes, dramatically increasing the spatial resolution and showing fine details of a large variety of celestial objects. The VLTI is arguably the world's most advanced optical device of this type. It has already demonstrated its powerful capabilities by addressing several key scientific issues, such as determining the size and the shape of a variety of stars (ESO PR 22/02, PR 14/03 and PR 31/03), measuring distances to stars (ESO PR 25/04), probing the innermost regions of the proto-planetary discs around young stars (ESO PR 27/04) or making the first detection by infrared interferometry of an extragalactic object (ESO PR 17/03). "Little Brothers" ESO PR Photo 07b/05 ESO PR Photo 07b/05 [Preview - JPEG: 597 x 400 pix - 47k] [Normal - JPEG: 1193 x 800 pix - 330k] [HiRes - JPEG: 5000 x 3354 pix - 10.0M] ESO PR Photo 07c/05 ESO PR Photo 07c/05

  8. Next VLT Instrument Ready for the Astronomers

    Science.gov (United States)

    2000-02-01

    FORS2 Commissioning Period Successfully Terminated The commissioning of the FORS2 multi-mode astronomical instrument at KUEYEN , the second FOcal Reducer/low dispersion Spectrograph at the ESO Very Large Telescope, was successfully finished today. This important work - that may be likened with the test driving of a new car model - took place during two periods, from October 22 to November 21, 1999, and January 22 to February 8, 2000. The overall goal was to thoroughly test the functioning of the new instrument, its conformity to specifications and to optimize its operation at the telescope. FORS2 is now ready to be handed over to the astronomers on April 1, 2000. Observing time for a six-month period until October 1 has already been allocated to a large number of research programmes. Two of the images that were obtained with FORS2 during the commissioning period are shown here. An early report about this instrument is available as ESO PR 17/99. The many modes of FORS2 The FORS Commissioning Team carried out a comprehensive test programme for all observing modes. These tests were done with "observation blocks (OBs)" that describe the set-up of the instrument and telescope for each exposure in all details, e.g., position in the sky of the object to be observed, filters, exposure time, etc.. Whenever an OB is "activated" from the control console, the corresponding observation is automatically performed. Additional information about the VLT Data Flow System is available in ESO PR 10/99. The FORS2 observing modes include direct imaging, long-slit and multi-object spectroscopy, exactly as in its twin, FORS1 at ANTU . In addition, FORS2 contains the "Mask Exchange Unit" , a motorized magazine that holds 10 masks made of thin metal plates into which the slits are cut by means of a laser. The advantage of this particular observing method is that more spectra (of more objects) can be taken with a single exposure (up to approximately 80) and that the shape of the slits can be

  9. Successful "First Light" for VLT High-Resolution Spectrograph

    Science.gov (United States)

    1999-10-01

    Great Research Prospects with UVES at KUEYEN A major new astronomical instrument for the ESO Very Large Telescope at Paranal (Chile), the UVES high-resolution spectrograph, has just made its first observations of astronomical objects. The astronomers are delighted with the quality of the spectra obtained at this moment of "First Light". Although much fine-tuning still has to be done, this early success promises well for new and exciting science projects with this large European research facility. Astronomical instruments at VLT KUEYEN The second VLT 8.2-m Unit Telescope, KUEYEN ("The Moon" in the Mapuche language), is in the process of being tuned to perfection before it will be "handed" over to the astronomers on April 1, 2000. The testing of the new giant telescope has been successfully completed. The latest pointing tests were very positive and, from real performance measurements covering the entire operating range of the telescope, the overall accuracy on the sky was found to be 0.85 arcsec (the RMS-value). This is an excellent result for any telescope and implies that KUEYEN (as is already the case for ANTU) will be able to acquire its future target objects securely and efficiently, thus saving precious observing time. This work has paved the way for the installation of large astronomical instruments at its three focal positions, all prototype facilities that are capable of catching the light from even very faint and distant celestial objects. The three instruments at KUEYEN are referred to by their acronyms UVES , FORS2 and FLAMES. They are all dedicated to the investigation of the spectroscopic properties of faint stars and galaxies in the Universe. The UVES instrument The first to be installed is the Ultraviolet Visual Echelle Spectrograph (UVES) that was built by ESO, with the collaboration of the Trieste Observatory (Italy) for the control software. Complete tests of its optical and mechanical components, as well as of its CCD detectors and of the complex

  10. ESO's Telescopes In memoriam Daniel Enard

    Science.gov (United States)

    Gilmozzi, Roberto

    2009-06-01

    The contributions of ESO to the art of telescope-making have come a long way since the early years, placing it, by the turn of the millennium, among the acknowledged leaders in the field. In this article I will give a brief history of what are, in my view, the highlights among these developments, from the 3.6-metre telescope through the NTT and VLT/I to the E-ELT.

  11. MOONS: a Multi-Object Optical and Near-infrared Spectrograph for the VLT

    CERN Document Server

    Cirasuolo, M; Bender, R; Bonifacio, P; Evans, C; Kaper, L; Oliva, E; Vanzi, L; Abreu, M; Atad-Ettedgui, E; Babusiaux, C; Bauer, F; Best, P; Bezawada, N; Bryson, I; Cabral, A; Caputi, K; Centrone, M; Chemla, F; Cimatti, A; Cioni, M-R; Clementini, G; Coelho, J; Daddi, E; Dunlop, J; Feltzing, S; Ferguson, A; Flores, H; Fontana, A; Fynbo, J; Garilli, B; Glauser, A; Guinouard, I; Hammer, F; Hastings, P; Hess, A; Ivison, R; Jagourel, P; Jarvis, M; Kauffman, G; Lawrence, A; Lee, D; Licausi, G; Lilly, S; Lorenzetti, D; Maiolino, R; Mannucci, F; McLure, R; Minniti, D; Montgomery, D; Muschielok, B; Nandra, K; Navarro, R; Norberg, P; Origlia, L; Padilla, N; Peacock, J; Pedicini, F; Pentericci, L; Pragt, J; Puech, M; Randich, S; Renzini, A; Ryde, N; Rodrigues, M; Royer, F; Saglia, R; Sanchez, A; Schnetler, H; Sobral, D; Speziali, R; Todd, S; Tolstoy, E; Torres, M; Venema, L; Vitali, F; Wegner, M; Wells, M; Wild, V; Wright, G

    2012-01-01

    MOONS is a new conceptual design for a Multi-Object Optical and Near-infrared Spectrograph for the Very Large Telescope (VLT), selected by ESO for a Phase A study. The baseline design consists of 1000 fibers deployable over a field of view of 500 square arcmin, the largest patrol field offered by the Nasmyth focus at the VLT. The total wavelength coverage is 0.8um-1.8um and two resolution modes: medium resolution and high resolution. In the medium resolution mode (R=4,000-6,000) the entire wavelength range 0.8um-1.8um is observed simultaneously, while the high resolution mode covers simultaneously three selected spectral regions: one around the CaII triplet (at R=8,000) to measure radial velocities, and two regions at R=20,000 one in the J-band and one in the H-band, for detailed measurements of chemical abundances. The grasp of the 8.2m Very Large Telescope (VLT) combined with the large multiplex and wavelength coverage of MOONS - extending into the near-IR - will provide the observational power necessary to...

  12. The VLT-FLAMES Tarantula survey

    NARCIS (Netherlands)

    Taylor, W.D.; Evans, C.J.; Henault-Brunet, V.; Bastian, N.; Beletsky, Y.; Bestenlehner, J.; Brott, I.; Cantiello, M.; Carraro, G.; Clark, J.S.; Crowther, P.A.; de Koter, A.; de Mink, S.E.; Doran, E.; Dufton, P.L.; Dunstall, P.; Gieles, M.; Grafener, G.; Herrero, A.; Howarth, I.D.; Langer, N.; Lennon, D.J.; Maiz-Apellaniz, J; Markova, N.; Najarro, P.; Puls, J.; Sana, H.A.A.; Simon-Diaz, S.; Smartt, S.J.; Stroud, V.E.; van Loon, J.T.; Vink, J.S.; Walborn, N.R.

    2011-01-01

    The VLT-FLAMES Tarantula Survey is an ESO Large Programme that has provided multi-epoch spectroscopy of over 1000 stars in the 30 Doradus region in the Large Magellanic Cloud. Armed with this unique dataset the assembled consortium is now addressing a broad range of fundamental questions in both ste

  13. When VLT Meets HST : The HUGS Survey

    NARCIS (Netherlands)

    Fontana, A.; Dunlop, J. S.; Paris, D.; Targett, T.; Boutsia, K.; Castellano, M.; Galametz, A.; Grazian, A.; McLure, R.; Merlin, E.; Pentericci, L.; Wuyts, S.; Almaini, O.; Caputi, K.; Chary, R.-R.; Cirasuolo, M.; Conselice, C.; Cooray, A.; Daddi, E.; Dickinson, M.; Faber, S. M.; Fazio, G.; Ferguson, H.; Giallongo, E.; Giavalisco, M.; Grogin, N.; Hathi, N.; Koekemoer, A.; Koo, D. C.; Lucas, R.; Nonino, M.; Rix, H.-W.; Renzini, A.; Rosario, D.; Santini, P.; Scarlata, C.; Sommariva, V.; Stark, D. P.; van der Wel, A.; Vanzella, E.; Wild, V.; Yan, H.; Zibetti, S.

    2014-01-01

    A new ultra-deep near-infrared imaging survey has been completed using the HAWK-I imager at the VLT. It is named HUGS (HAWK-I Ultra Deep Survey and GOODS Survey) and delivers the deepest, highest quality images ever collected in the K-band. HUGS complements the data delivered by the HST CANDELS surv

  14. Evolution of operations for the Survey Telescope at Paranal

    Science.gov (United States)

    Romero, Cristian M.; Mieske, Steffen; Brillant, Stéphane; Pino, Andres; Cerda, Susana; Reyes, Claudia; La Fuente, Carlos

    2016-07-01

    Since 2009, operations began at the Survey Telescopes at Paranal Observatory. The surveys aimed to observe using a large field of view targeting much fainter sources and covering wide areas of sky quickly. The first to enter operations was VISTA (Visible and Infrared Survey Telescope for Astronomy) and then the VST Telescope (VLT Survey Telescope). The survey telescopes introduced a change into the operational model of the time. The observations were wholly conducted by the telescope and instrument operator without the aid of a support astronomer. This prompted the gradual and steady improvement of tools for the operation of the observatory both generally and in particular for the Survey Telescopes. Examples of these enhancements include control systems for image quality, selection of OBs, logging of evening activities, among others. However, the new generation instruments at the Very Large Telescope (VLT) posed a new challenge to the observatory from a scientific and operational point of view. As these new systems were more demanding and complex, they would be more complicated to operate and require additional support. Hence, the focus of this study is to explore the possible development and optimization of the operations of the Survey telescopes, which would give greater operational flexibility in regards to the new generation instruments. Moreover, we aim to evaluate the feasibility of redistributing of telescope operators during periods of increased demand from other VLT systems.

  15. Paper Productivity of Ground-based Large Optical Telescopes from 2000 to 2009

    CERN Document Server

    KIM, Sang Chul

    2011-01-01

    We present an analysis of the scientific ("refereed") paper productivity of the current largest (diameter >8 m) ground-based optical(-infrared) telescopes during the ten year period from 2000 to 2009. The telescopes for which we have gathered and analysed the scientific publication data are the two 10 m Keck telescopes, the four 8.2 m Very Large Telescopes (VLT), the two 8.1 m Gemini telescopes, the 8.2 m Subaru telescope, and the 9.2 m Hobby-Eberly Telescope (HET). We have analysed the rate of papers published in various astronomical journals produced by using these telescopes. While the total numbers of papers from these observatories are largest for the VLT followed by Keck, Gemini, Subaru, and HET, the number of papers produced by each component of the telescopes are largest for Keck followed by VLT, Subaru, Gemini, and HET. In 2009, each telescope of the Keck, VLT, Gemini, Subaru, and HET observatories produced 135, 109, 93, 107, and 5 refereed papers, respectively. We have shown that each telescope of t...

  16. VLT Observations Confirm that the Universe Was Hotter in the Past

    Science.gov (United States)

    2000-12-01

    UVES Measures the Cosmic Temperature 12 Billion Years Ago Summary A fundamental prediction of the Big Bang theory has finally been verified . For the first time, an actual measurement has been made of the temperature of the cosmic microwave background radiation, at a time when the Universe was only about 2.5 billion years old . This fundamental and very difficult observation was achieved by a team of astronomers from India, France and ESO [1]. They obtained a detailed spectrum of a quasar in the distant Universe, using the UV-Visual Echelle Spectrograph (UVES) instrument at the ESO 8.2-m VLT KUEYEN telescope at the Paranal Observatory. If the Universe was indeed formed in a Big Bang, as most astrophysicists believe, the glow of this primeval fireball should have been warmer in the past. This is exactly what is found by the new measurements. The analysis of the VLT spectrum of the distant quasar not only gives the definitive proof of the presence of the relict radiation in the early Universe, it also shows that it was indeed significantly warmer than it is today, as predicted by the theory. PR Photo 35/00 : VLT spectrum of the distant quasar PKS 1232+0815 , displaying lines of carbon atoms from an intervening cloud in which the cosmic temperature was measured. The Cosmic Microwave Background Radiation (CMBR) One of the fundamental predictions of the Hot Big Bang theory for the creation of the Universe is the existence of the Cosmic Microwave Background Radiation (CMBR) . This relict radiation of the primeval fireball was discovered in 1964 by means of radio observations by American physicists Arno A. Penzias and Robert W. Wilson , who were rewarded with the Nobel Prize in 1978. Precision measurements by the COBE satellite later showed that this ancient radiation fills the Universe, with a present-day temperature of slightly less than 3 degrees above the absolute zero (2.7 K [Kelvin], or -270.4 °C). This radiation comes from all directions and is extremely uniform

  17. Athermal laser launch telescopes

    NARCIS (Netherlands)

    Kamphues, F.G.; Henselmans, R.; Rijnveld, N.; Lemmen, M.H.J.; Doelman, N.J.; Nijkerk, M.D.

    2011-01-01

    ESO has developed a concept for a compact laser guide star unit for use in future Adaptive Optics (AO) systems. A small powerful laser is combined with a telescope that launches the beam, creating a single modular unit that can be mounted directly on a large telescope. This approach solves several

  18. Athermal laser launch telescopes

    NARCIS (Netherlands)

    Kamphues, F.G.; Henselmans, R.; Rijnveld, N.; Lemmen, M.H.J.; Doelman, N.J.; Nijkerk, M.D.

    2011-01-01

    ESO has developed a concept for a compact laser guide star unit for use in future Adaptive Optics (AO) systems. A small powerful laser is combined with a telescope that launches the beam, creating a single modular unit that can be mounted directly on a large telescope. This approach solves several o

  19. VLT FORS2 comparative transmission spectral survey of clear and cloudy exoplanet atmospheres

    Science.gov (United States)

    Nikolov, Nikolay; Sing, David; Gibson, Neale; Evans, Thomas; Barstow, Joanna Katy; Kataria, Tiffany; Wilson, Paul A.

    2016-10-01

    Transmission spectroscopy is a key to unlocking the secrets of close-in exoplanet atmospheres. Observations have started to unveil a vast diversity of irradiated giant planet atmospheres with clouds and hazes playing a definitive role across the entire mass and temperature regime. We have initiated a ground-based, multi-object transmission spectroscopy of a hand full of hot Jupiters, covering the wavelength range 360-850nm using the recently upgraded FOcal Reducer and Spectrograph (FORS2) mounted on the Very Large Telescope (VLT) at the European Southern Observatory (ESO). These targets were selected for comparative follow-up as their transmission spectra showed evidence for alkali metal absorption, based on the results of Hubble Space Telescope (HST) observations. This talk will discuss the first results from the programme, demonstrating excellent agreement between the transmission spectra measured from VLT and HST and further reinforce the findings of clear, cloudy and hazy atmospheres. More details will be discussed on the narrow alkali features obtained with FORS2 at higher resolution, revealing its high potential in securing optical transmission spectra. These FORS2 observations are the first ground-based detections of clear, cloudy and hazy hot-Jupiter atmosphere with a simultaneous detections of Na, K, and H2 Rayleigh scattering. Our program demonstrates the large potential of the instrument for optical transmission spectroscopy, capable of obtaining HST-quality light curves from the ground. Compared to HST, the larger aperture of VLT will allow for fainter targets to be observed and higher spectral resolution, which can greatly aid comparative exoplanet studies. This is important for further exploring the diversity of exoplanet atmospheres and is particularly complementary to the near- and mid-IR regime, to be covered by the upcoming James-Webb Space Telescope (JWST) and is readily applicable to less massive planets down to super-Earths.

  20. Final binary star results from the ESO VLT Lunar occultations program

    Energy Technology Data Exchange (ETDEWEB)

    Richichi, A. [National Astronomical Research Institute of Thailand, 191 Siriphanich Bldg., Huay Kaew Road, Suthep, Muang, Chiang Mai 50200 (Thailand); Fors, O. [Departament Astronomia i Meteorologia and Institut de Ciències del Cosmos (ICC), Universitat de Barcelona (UB/IEEC), Martí i Franqués 1, E-08028 Barcelona (Spain); Cusano, F. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Ivanov, V. D., E-mail: andrea4work@gmail.com [European Southern Observatory, Ave. Alonso de Cordova 3107, Casilla 19001, Santiago 19 (Chile)

    2014-03-01

    We report on 13 subarcsecond binaries, detected by means of lunar occultations in the near-infrared at the ESO Very Large Telescope (VLT). They are all first-time detections except for the visual binary HD 158122, which we resolved for the first time in the near-infrared. The primaries have magnitudes in the range K = 4.5-10.0, and companions in the range K = 6.8-11.1. The magnitude differences have a median value of 2.4, with the largest being 4.6. The projected separations are in the range of 4-168 mas, with a median of 13 mas. We discuss and compare our results with the available literature. With this paper, we conclude the mining for binary star detections in the 1226 occultations recorded at the VLT with the ISAAC instrument. We expect that the majority of these binaries may be unresolvable by adaptive optics on current telescopes, and they might be challenging for long-baseline interferometry. However, they constitute an interesting sample for future larger telescopes and for astrometric missions such as GAIA.

  1. VLT FORS2 comparative transmission spectral survey of clear and cloudy exoplanet atmospheres

    Science.gov (United States)

    Nikolov, Nikolay; Sing, David K.; Gibson, Neale; Fortney, Jonathan J.; Evans, Tom M.; Barstow, Joanna; Kataria, Tiffany; Wilson, Paul

    2017-01-01

    Thousands of transiting exoplanets are known today but not many have been studied in transmission. While observations with the Hubble Space Telescope (HST) have started to reveal a diversity of atmosphere types, drawing robust conclusions about the underlying population is hampered by the small sample size. This can be greatly aided by ground-based telescopes, equipped with multi-object spectrographs by their unprecedented access to the abundance of fainter systems that HST cannot observe. We have initiated a ground-based, multi-object transmission spectroscopy of a handful of hot gas-giants, covering the wavelength range 360-850nm, using the recently upgraded FOcal Reducer and Spectrograph (FORS2) mounted on the Very Large Telescope (VLT). These exoplanets were selected for a comparative follow-up as their transmission spectra showed evidence for alkali metal absorption, based on the results of HST observations. Here we will discuss first results from the program, demonstrating an excellent agreement between the transmission spectra measured from VLT and HST and detections of Na and K absorption and scattering by clouds/hazes in the atmospheres of several exoplanets. More details will be discussed on the narrow alkali features obtained with FORS2 at higher resolution, revealing its high potential in obtaining optical transmission spectra, which can greatly aid comparative exoplanet studies.

  2. ESO Telescope Designer Raymond Wilson Wins Prestigious Kavli Award for Astrophysics

    Science.gov (United States)

    2010-06-01

    with four individual telescopes with 17.5 cm thick 8.2-metre mirrors. Active optics has contributed towards making the VLT the world's most successful ground-based observatory and will be an integral part of ESO's European Extremely Large Telescope (E-ELT) project. Active optics technology is also part of the twin 10-metre Keck telescopes, the Subaru telescope's 8.2-metre mirror and the two 8.1-metre Gemini telescopes. Co-prize winners Jerry Nelson and Roger Angel respectively pioneered the use of segmentation in telescope primary mirrors - as used on the Keck telescopes, and the development of lightweight mirrors with short focal ratios. A webcast from Oslo, Norway, announcing the prize winners is available at www.kavlifoundation.org and www.kavliprize.no. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

  3. Trends and developments in VLT data papers as seen through telbib

    Science.gov (United States)

    Bordelon, Dominic; Grothkopf, Uta; Meakins, Silvia; Sterzik, Michael

    2016-07-01

    The ESO Telescope Bibliography (telbib; http://telbib.eso.org) is a database of refereed papers published by the ESO users community. It links data in the ESO Science Archive with the published literature, and vice versa. Developed and maintained by the ESO library, telbib also provides insights into the organization's research output and impact as measured through bibliometric studies. Numerous reports, statistics, and visualizatons derived from telbib help to understand the way in which the user community uses ESO/VLT data in publications. Based on selected use cases, we will showcase recent trends and developments.

  4. Validation through simulations of a C_n^2 profiler for the ESO/VLT Adaptive Optics Facility

    Science.gov (United States)

    Garcia-Rissmann, A.; Guesalaga, A.; Kolb, J.; Le Louarn, M.; Madec, P.-Y.; Neichel, B.

    2015-04-01

    The Adaptive Optics Facility (AOF) project envisages transforming one of the VLT units into an adaptive telescope and providing its ESO (European Southern Observatory) second generation instruments with turbulence-corrected wavefronts. For MUSE and HAWK-I this correction will be achieved through the GALACSI and GRAAL AO modules working in conjunction with a 1170 actuators deformable secondary mirror (DSM) and the new Laser Guide Star Facility (4LGSF). Multiple wavefront sensors will enable GLAO (ground layer adaptive optics) and LTAO (laser tomography adaptive optics) capabilities, whose performance can greatly benefit from a knowledge about the stratification of the turbulence in the atmosphere. This work, totally based on end-to-end simulations, describes the validation tests conducted on a C_n^2 profiler adapted for the AOF specifications. Because an absolute profile calibration is strongly dependent on a reliable knowledge of turbulence parameters r0 and L0, the tests presented here refer only to normalized output profiles. Uncertainties in the input parameters inherent to the code are tested as well as the profiler response to different turbulence distributions. It adopts a correction for the unseen turbulence, critical for the GRAAL mode, and highlights the effects of masking out parts of the corrected wavefront on the results. Simulations of data with typical turbulence profiles from Paranal were input to the profiler, showing that it is possible to identify reliably the input features for all the AOF modes.

  5. The MaNGA Integral Field Unit Fiber Feed System for the Sloan 2.5 m Telescope

    CERN Document Server

    Drory, N; Bershady, M A; Bundy, K; Gunn, J; Law, D R; Smith, M; Stoll, R; Tremonti, C A; Wake, D A; Yan, R; Weijmans, A M; Byler, N; Cherinka, B; Cope, F; Eigenbrot, A; Harding, P; Holder, D; Huehnerhoff, J; Jaehnig, K; Jansen, T C; Klaene, M; Paat, A M; Percival, J; Sayres, C

    2014-01-01

    We describe the design, manufacture, and performance of bare-fiber integral field units (IFUs) for the SDSS-IV survey MaNGA (Mapping Nearby Galaxies at APO) on the the Sloan 2.5 m telescope at Apache Point Observatory (APO). MaNGA is a luminosity-selected integral-field spectroscopic survey of 10,000 local galaxies covering 360-1030 nm at R ~ 2200. The IFUs have hexagonal dense packing of fibers with packing regularity of 3 um (RMS), and throughput of 96+/-0.5% from 350 nm to 1 um in the lab. Their sizes range from 19 to 127 fibers (3-7 hexagonal layers) using Polymicro FBP 120:132:150 um core:clad:buffer fibers to reach a fill fraction of 56%. High throughput (and low focal-ratio degradation) is achieved by maintaining the fiber cladding and buffer intact, ensuring excellent surface polish, and applying a multi-layer AR coating of the input and output surfaces. In operations on-sky, the IFUs show only an additional 2.3% FRD-related variability in throughput despite repeated mechanical stressing during plate ...

  6. SparsePak: A Formatted Fiber Field Unit for The WIYN Telescope Bench Spectrograph. I. Design, Construction, and Calibration

    CERN Document Server

    Bershady, M A; Harker, J; Ramsey, L W; Verheijen, M A W

    2004-01-01

    We describe the design and construction of a formatted fiber field-unit, SparsePak, and characterize its optical and astrometric performance. This array is optimized for spectroscopy of low-surface brightness, extended sources in the visible and near-infrared. SparsePak contains 82, 4.7" fibers subtending an area of 72"x71" in the telescope focal plane, and feeds the WIYN Bench spectrograph. Together, these instruments are capable of achieving spectral resolutions of lambda/dlambda ~ 20000 and an area--solid-angle product of ~140 arcsec^2 m^2 per fiber. Laboratory measurements of SparsePak lead to several important conclusions on the design of fiber termination and cable curvature to minimize focal ratio degradation. SparsePak itself has throughput >80% redwards of 5200 A, and 90-92% in the red. Fed at f/6.3, the cable delivers an output 90% encircled energy at nearly f/5.2. This has implications for performance gains if the WIYN Bench Spectrograph had a faster collimator. Our approach to integral-field spect...

  7. VLT Smashes the Record of the Farthest Known Galaxy

    Science.gov (United States)

    2004-03-01

    formed which could illuminate the vast space. The Universe was a cold and opaque place. This sombre era is therefore quite reasonably dubbed the "Dark Ages". A few hundred million years later, the first generation of stars and, later still, the first galaxies and quasars, produced intense ultraviolet radiation, gradually lifting the fog over the Universe. This was the end of the Dark Ages and, with a term again taken over from human history, is sometimes referred to as the "Cosmic Renaissance". Astronomers are trying to pin down when - and how - exactly the Dark Ages finished. This requires looking for the remotest objects, a challenge that only the largest telescopes, combined with a very careful observing strategy, can take up. Using a Gravitational Telescope With the advent of 8-10 meter class telescopes spectacular progress has been achieved during the last decade. Indeed it has since become possible to observe with some detail several thousand galaxies and quasars out to distances of nearly 12 billion light-years (i.e. up to a redshift of 3 [3]). In other words astronomers are now able to study individual galaxies, their formation, evolution, and other properties over typically 85 % of the past history of the Universe. Further in the past, however, observations of galaxies and quasars become scarce. Currently, only a handful of very faint galaxies are seen approximately 1,200 to 750 million years after the Big Bang (redshift 5-7). Beyond that, the faintness of these sources and the fact their light is shifted from the optical to the near infrared has so far severely limited the studies. An important breakthrough in this quest for the earliest formed galaxy has now been achieved by a team of French and Swiss astronomers [2] using ESO's Very Large Telescope (VLT) equipped with the near-infrared sensitive instrument ISAAC. To accomplish this, they had to combine the light amplification effect of a cluster of galaxies - a Gravitational Telescope - with the light

  8. VLT polarimetry observations of PSR B0656+14

    CERN Document Server

    Mignani, R P; Shearer, A; Testa, V; Sowikowska, A; Rudak, B; Krzeszowki, K; Kanbach, G

    2015-01-01

    Optical polarisation measurements are key tests for different models of the pulsar magnetosphere. Furthermore, comparing the relative orientation of the phase-averaged linear polarisation direction and the pulsar proper motion vector may unveil a peculiar alignment, clearly seen in the Crab pulsar. Our goal is to obtain the first measurement of the phase-averaged optical linear polarisation of the fifth brightest optical pulsar, PSR\\, B0656+14, which has also a precisely measured proper motion, and verify a possible alignment between the polarisation direction and the proper motion vector. We carried out observations with the Very Large Telescope (VLT) to measure the phase-averaged optical polarisation degree (P.D.) and position angle (P.A.) of PSR B0656+14. We measured a P.D. of $11.9\\%\\pm5.5\\%$ and a P.A. of $125.8\\degr\\pm13.2\\degr$, measured East of North. Albeit of marginal significance, this is the first measurement of the phase-averaged optical P. D. for this pulsar. Moreover, we found that the P.A. of ...

  9. Astrometric precision of observations at VLT/FORS2

    CERN Document Server

    Lazorenko, P F

    2005-01-01

    In this paper we test the astrometric precision of VLT/FORS2 observations using a serie of CCD frames taken in Galactic bulge area. A special reduction method based on symmetrization of reference fields was used to reduce the atmospheric image motion. Positional precision of unsaturated R=16 mag star images at 17 sec exposure and 0.55 arcsec seeing was found to be equal to 300 microarcsec. The total error of observations was decomposed into components. It was shown that astrometric error depends largely on the photon centroiding error of the target (250 microarcsec for 16 mag stars) while the image motion is much less (110 microarcsec). At galactic latitudes to about 20 degrees, precision for a serie of frames with a 10 min total exposure is estimated to be 30-50 microarcsec for 14-16 mag stars providing the images are not overexposed and the filter R "special" is used. Error estimates for fields with smaller sky star density are given. We conclude that astrometric observations with large telescopes, under op...

  10. Deployable Integral Field Units, Multislits, and Image Slicer for the Goodman Imaging Spectrograph on the SOAR Telescope

    Science.gov (United States)

    Cecil, Gerald N.; Moffett, A. J.; Cui, Y.; Eckert, K. D.; McBride, J.; Kannappan, S.; Keller, K.; Barlow, B. N.; Dunlap, B.; Bland-Hawthorn, J.

    2010-01-01

    The Goodman Imager-Spectrograph on the 4.1m SOAR telescope has operated on Cerro Pachon, Chile with volume-phase holographic gratings in long-slit mode since its commissioning in 2008. Recently, UNC graduate students played key roles to implement robust upgrades for multi-object spectroscopy that will soon be available to US astronomers through the NOAO time share on SOAR: • Multislits over 3x5 arcmin, generated on PCB solder stencils with exceptional sharpness compared to conventional laser cuts, initially to survey globular clusters for pulsating hot sub-dwarfs • An image slicer to obtain 3 simultaneous parallel spectra 70-arcsec long, 1- or 2-arcsec wide, spanning 320-750 nm to map stellar and gaseous emission and mass over the 1500 galaxies in the RESOLVE survey underway on SOAR • Four integral field units, each composed of 5-arcsec diameter, fused bundles of 0.5-arcsec diameter thin-clad optical fiber, independently deployed over a 10x5 arcmin field targeted by an EMCCD also used for Lucky Imaging. Initially will study aperture effects in single fiber surveys, extragalactic globular clusters, and demonstrate technology prior to deployment on larger telescopes • New wheels supporting a large set of existing narrow-band and Sloan filters • A trombone-style atmospheric dispersion compensator that corrects the full 12-arcmin diameter science field down to 30 deg elevation. Working in UNC's Goodman Laboratory for Astronomical Instrumentation, students employed SolidWorks and ZEMAX to design parts for in-house CAM on CNC machines and a 3D printer. All motors are controlled by LabVIEW as is the SOAR TCS. The deployable IFU axes are controlled by Quicksilver Controls Inc. intelligent servos and $80 model robot (Firgelli Corp.) actuators driven by a PIC-microcontroller and a student designed custom PCB. Upgrades and students were supported by $200K from SOAR Corporation, Research Corporation, NSF, and UNC competitive funds, and NC NASA Space Grant, Sigma Xi

  11. VLT/SINFONI spectroscopy of the superantennae

    Directory of Open Access Journals (Sweden)

    J. Reunanen

    2007-01-01

    Full Text Available Presentamos los resultados de espectroscopia de campo integral en bandas H y K VLT/SINFONI de IRAS 19254-7245 (Superantennae, una ULRIG cercana con un AGN embebido. Los mapas de las líneas, campos de velocidades y mapas de dispersión de velocidades se presentan para varias líneas de emisión. Las proporciones de las líneas de emisión de H2 son consistentes con la excitación térmica, debida probablemente a choques.

  12. Data Flow System for the VLT Interferometer

    Science.gov (United States)

    Ballester, P.; Licha, T.; Percheron, I.; Sabet, C.

    2006-07-01

    A milestone on the accuracy of angular measurements is reached with each new instrument on the VLT interferometer: about 10 milliarcsec for MIDI (N Band), 1 milliarcsec for AMBER (JHK bands) and, later, the ultimate goal of 10 microarcsec for the PRIMA imaging and astrometry facility. Extracting the science information from these measurements requires a unified understanding of the data obtained by modelling, homogeneous calibration of large datasets and robust data reduction methods. We describe in this poster the operational tools provided for observation preparation, pipeline processing, and data quality control.

  13. ESO-VLT Science Data Processing

    Science.gov (United States)

    Hanuschik, Reinhard; Data Processing; Quality Control Group

    2017-09-01

    "In the past three years the QC group at ESO has installed an efficient process to create science-grade data products from VLT instruments. With the focus on spectroscopic observations, these data products are complementary to the (externally provided) data products from the surveys. The production line combines efficient mass production (more than one million spectra have been generated so far), previews, and quality control. All data products are available to the community through the ESO archive interface. The talk will highlight the most recent addition, the MUSE datacubes."

  14. APE: the Active Phasing Experiment to test new control system and phasing technology for a European Extremely Large Optical Telescope

    Science.gov (United States)

    Gonte, F.; Yaitskova, N.; Derie, F.; Constanza, A.; Brast, R.; Buzzoni, B.; Delabre, B.; Dierickx, P.; Dupuy, C.; Esteves, R.; Frank, C.; Guisard, S.; Karban, R.; Koenig, E.; Kolb, J.; Nylund, M.; Noethe, L.; Surdej, I.; Courteville, A.; Wilhelm, R.; Montoya, L.; Reyes, M.; Esposito, S.; Pinna, E.; Dohlen, K.; Ferrari, M.; Langlois, M.

    2005-08-01

    The future European Extremely Large Telescope will be composed of one or two giant segmented mirrors (up to 100 m of diameter) and of several large monolithic mirrors (up to 8 m in diameter). To limit the aberrations due to misalignments and defective surface quality it is necessary to have a proper active optics system. This active optics system must include a phasing system to limit the degradation of the PSF due to misphasing of the segmented mirrors. We will present the lastest design and development of the Active Phasing Experiment that will be tested in laboratory and on-sky connected to a VLT at Paranal in Chile. It includes an active segmented mirror, a static piston plate to simulate a secondary segmented mirror and of four phasing wavefront sensors to measure the piston, tip and tilt of the segments and the aberrations of the VLT. The four phasing sensors are the Diffraction Image Phase Sensing Instrument developed by Instituto de Astrofisica de Canarias, the Pyramid Phasing Sensor developed by Arcetri Astrophysical Observatory, the Shack-Hartmann Phasing Sensor developed by the European Southern Observatory and the Zernike Unit for Segment phasing developed by Laboratoire d'Astrophysique de Marseille. A reference measurement of the segmented mirror is made by an internal metrology developed by Fogale Nanotech. The control system of Active Phasing Experiment will perform the phasing of the segments, the guiding of the VLT and the active optics of the VLT. These activities are included in the Framework Programme 6 of the European Union.

  15. Mid-IR observations of NGC 1068 with VLT/VISIR

    CERN Document Server

    Poncelet, A; Perrin, G; Sol, H; Lagage, P O

    2006-01-01

    We present a speckle analysis of the active galactic nucleus (AGN) inside the archetype Seyfert type 2 galaxy NGC 1068. This study is based on 12.8 microns images obtained with the burst mode of VISIR (the Very Large Telescope Imager and Spectrometer in the InfraRed). The interferometric processing allows to push the resolution far below the diffraction limit of a 8m telescope in the N-band and to trace two main contributions to the mid-IR flux inside the nucleus. It also allows to partially fill the lack of visibility points at low spatial frequencies. The confrontation with VLT/MIDI (the Mid-InfrareD Interferometer) data points helps to establish the link between dust in the vicinity of the central engine and inside the ionisation cone to get a multi-scale picture of mid-IR sources emitting in the nucleus of NGC 1068.

  16. The Space Missions WAXS/WFXT and SWIFT New Targets for the VLT

    CERN Document Server

    Chincarini, G L

    1999-01-01

    At OAB we were, during the year 1998, deeply involved in planning two important space missions for which very large ground based telescopes, VLT in particular, would play a very large and important role in the optical followup. The study of the first mission, Wide Angle X-ray Survey using a Wide Field X-ray Telescope, was coordinated by the Observatory of Brera, involved mainly Italian industries and resulted in a proposal to the Italian Space Agency under the Small Satellite Program. The second mission, SWIFT, has been coordinated and directed by the Goddard Space Flight Center and resulted in the submission of a proposal to NASA under the MIDEX program. The science goal of this mission is the detection and study of the Gamma-ray bursts.

  17. VLT/UVES constraints on the cosmological variability of the fine-structure constant

    CERN Document Server

    Levshakov, S A; Molaro, P; D'Odorico, S

    2004-01-01

    A differential many-multiplet (DMM) technique is developed to probe the variability of alpha. Applied to the FeII lines of the metal absorption line system at zabs = 1.839 in the spectrum of Q1101-264 obtained by means of the UV-Visual Echelle Spectrograph (UVES) at the ESO Very Large Telescope (VLT), the DMM provides da/a = (4.3+/-7.8) 10^{-6}.The zabs = 1.15 FeII system toward HE0515-4414 has been re-analyzed by the DMM method thus obtaining for the combined sample da/a = (0.7+/-3.1) 10^{-6}. These values are shifted with respect to the Keck/HIRES mean da/a = (-5.7+/-1.1) 10^{-6} (Murphy et al. 2004) at very high confidence level (95%). The fundamental photon noise limitation in the da/a measurement with the VLT/UVES is discussed to figure the prospects for future observations. It is suggested that with a spectrograph of 10 times the UVES resolution coupled to a 100m class telescope the present Oklo level (da/a >= 4.5 10^{-8}) can be achieved along cosmological distances with differential measurements of da...

  18. VLT Detects First Superstorm on Exoplanet

    Science.gov (United States)

    2010-06-01

    Astronomers have measured a superstorm for the first time in the atmosphere of an exoplanet, the well-studied "hot Jupiter" HD209458b. The very high-precision observations of carbon monoxide gas show that it is streaming at enormous speed from the extremely hot day side to the cooler night side of the planet. The observations also allow another exciting "first" - measuring the orbital speed of the exoplanet itself, providing a direct determination of its mass. The results appear this week in the journal Nature. "HD209458b is definitely not a place for the faint-hearted. By studying the poisonous carbon monoxide gas with great accuracy we found evidence for a super wind, blowing at a speed of 5000 to 10 000 km per hour" says Ignas Snellen, who led the team of astronomers. HD209458b is an exoplanet of about 60% the mass of Jupiter orbiting a solar-like star located 150 light-years from Earth towards the constellation of Pegasus (the Winged Horse). Circling at a distance of only one twentieth the Sun-Earth distance, the planet is heated intensely by its parent star, and has a surface temperature of about 1000 degrees Celsius on the hot side. But as the planet always has the same side to its star, one side is very hot, while the other is much cooler. "On Earth, big temperature differences inevitably lead to fierce winds, and as our new measurements reveal, the situation is no different on HD209458b," says team member Simon Albrecht. HD209458b was the first exoplanet to be found transiting: every 3.5 days the planet moves in front of its host star, blocking a small portion of the starlight during a three-hour period. During such an event a tiny fraction of the starlight filters through the planet's atmosphere, leaving an imprint. A team of astronomers from the Leiden University, the Netherlands Institute for Space Research (SRON), and MIT in the United States, have used ESO's Very Large Telescope and its powerful CRIRES spectrograph to detect and analyse these faint

  19. Space Telescope.

    Science.gov (United States)

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

  20. SCIENCE OPPORTUNITIES ON THE VLT INTERFEROMETER

    Directory of Open Access Journals (Sweden)

    M. Schöller

    2010-01-01

    Full Text Available El interferómetro del VLT está desde hace varios años en operaciones científicas, con nuevas oportunidades disponibles cada vez que nuevas instalaciones están siendo integradas. La mayor parte de estos pasos son fácilmente visibles, pero algunas posibilidades se presentan a partir de mejoras simples. Detallo el potencial científico del VLTI, dando una descripción de la infraestructura y los modos ofrecidos por los instrumentos. Luego examino las limitaciones fijadas por la accesibilidad del cielo, flujo del objeto en el espectro visible e infrarrojo, o la morfología del objeto, seguida por una discusión de qué información se puede extraer de las mediciones del VLTI. Finalizo con una perspectiva en las mejoras futuras del VLTI.

  1. The MaNGA integral field unit fiber feed system for the Sloan 2.5 m telescope

    Energy Technology Data Exchange (ETDEWEB)

    Drory, N. [McDonald Observatory, The University of Texas at Austin, 1 University Station, Austin, TX 78712 (United States); MacDonald, N.; Byler, N. [Department of Astronomy, University of Washington, Box 351580 Seattle, WA 98195 (United States); Bershady, M. A.; Smith, M.; Tremonti, C. A.; Wake, D. A.; Eigenbrot, A.; Jaehnig, K. [Department of Astronomy, University of Wisconsin, 475 N. Charter St., Madison, WI 53706 (United States); Bundy, K. [Kavli Institute for the Physics and Mathematics of The Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, The University of Tokyo, Kashiwa, Japan 277-8583 (Japan); Gunn, J. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Law, D. R.; Cherinka, B. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George St, Toronto, ON M5S 3H4 (Canada); Stoll, R. [C Technologies, Inc., 757 Route 202/206, Bridgewater, NJ 08807 (United States); Yan, R. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky, 40506-0055 (United States); Weijmans, A. M. [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Cope, F.; Holder, D.; Huehnerhoff, J. [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Harding, P., E-mail: drory@astro.as.utexas.edu [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); and others

    2015-02-01

    We describe the design, manufacture, and performance of bare-fiber integral field units (IFUs) for the SDSS-IV survey Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) on the the Sloan 2.5 m telescope at Apache Point Observatory. MaNGA is a luminosity-selected integral-field spectroscopic survey of 10{sup 4} local galaxies covering 360–1030 nm at R∼2200. The IFUs have hexagonal dense packing of fibers with packing regularity of 3 μm (rms), and throughput of 96 ± 0.5% from 350 nm to 1 μm in the lab. Their sizes range from 19 to 127 fibers (3–7 hexagonal layers) using Polymicro FBP 120:132:150 μm core:clad:buffer fibers to reach a fill fraction of 56%. High throughput (and low focal-ratio degradation (FRD)) is achieved by maintaining the fiber cladding and buffer intact, ensuring excellent surface polish, and applying a multi-layer anti-reflection (AR) coating of the input and output surfaces. In operations on-sky, the IFUs show only an additional 2.3% FRD-related variability in throughput despite repeated mechanical stressing during plate plugging (however other losses are present). The IFUs achieve on-sky throughput 5% above the single-fiber feeds used in SDSS-III/BOSS, attributable to equivalent performance compared to single fibers and additional gains from the AR coating. The manufacturing process is geared toward mass-production of high-multiplex systems. The low-stress process involves a precision ferrule with a hexagonal inner shape designed to lead inserted fibers to settle in a dense hexagonal pattern. The ferrule ID is tapered at progressively shallower angles toward its tip and the final 2 mm are straight and only a few microns larger than necessary to hold the desired number of fibers. Our IFU manufacturing process scales easily to accommodate other fiber sizes and can produce IFUs with substantially larger fiber counts. To assure quality, automated testing in a simple and inexpensive system enables complete characterization of

  2. The MaNGA Integral Field Unit Fiber Feed System for the Sloan 2.5 m Telescope

    Science.gov (United States)

    Drory, N.; MacDonald, N.; Bershady, M. A.; Bundy, K.; Gunn, J.; Law, D. R.; Smith, M.; Stoll, R.; Tremonti, C. A.; Wake, D. A.; Yan, R.; Weijmans, A. M.; Byler, N.; Cherinka, B.; Cope, F.; Eigenbrot, A.; Harding, P.; Holder, D.; Huehnerhoff, J.; Jaehnig, K.; Jansen, T. C.; Klaene, M.; Paat, A. M.; Percival, J.; Sayres, C.

    2015-02-01

    We describe the design, manufacture, and performance of bare-fiber integral field units (IFUs) for the SDSS-IV survey Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) on the the Sloan 2.5 m telescope at Apache Point Observatory. MaNGA is a luminosity-selected integral-field spectroscopic survey of 104 local galaxies covering 360-1030 nm at R˜ 2200. The IFUs have hexagonal dense packing of fibers with packing regularity of 3 μm (rms), and throughput of 96 ± 0.5% from 350 nm to 1 μm in the lab. Their sizes range from 19 to 127 fibers (3-7 hexagonal layers) using Polymicro FBP 120:132:150 μm core:clad:buffer fibers to reach a fill fraction of 56%. High throughput (and low focal-ratio degradation (FRD)) is achieved by maintaining the fiber cladding and buffer intact, ensuring excellent surface polish, and applying a multi-layer anti-reflection (AR) coating of the input and output surfaces. In operations on-sky, the IFUs show only an additional 2.3% FRD-related variability in throughput despite repeated mechanical stressing during plate plugging (however other losses are present). The IFUs achieve on-sky throughput 5% above the single-fiber feeds used in SDSS-III/BOSS, attributable to equivalent performance compared to single fibers and additional gains from the AR coating. The manufacturing process is geared toward mass-production of high-multiplex systems. The low-stress process involves a precision ferrule with a hexagonal inner shape designed to lead inserted fibers to settle in a dense hexagonal pattern. The ferrule ID is tapered at progressively shallower angles toward its tip and the final 2 mm are straight and only a few microns larger than necessary to hold the desired number of fibers. Our IFU manufacturing process scales easily to accommodate other fiber sizes and can produce IFUs with substantially larger fiber counts. To assure quality, automated testing in a simple and inexpensive system enables complete characterization of throughput and

  3. The VLT Measures the Shape of a Type Ia Supernova

    Science.gov (United States)

    2003-08-01

    First Polarimetric Detection of Explosion Asymmetry has Cosmological Implications Summary An international team of astronomers [2] has performed new and very detailed observations of a supernova in a distant galaxy with the ESO Very Large Telescope (VLT) at the Paranal Observatory (Chile). They show for the first time that a particular type of supernova, caused by the explosion of a "white dwarf", a dense star with a mass around that of the Sun, is asymmetric during the initial phases of expansion . The significance of this observation is much larger than may seem at a first glance . This particular kind of supernova, designated "Type Ia", plays a very important role in the current attempts to map the Universe. It has for long been assumed that Type Ia supernovae all have the same intrinsic brightness , earning them a nickname as "standard candles". If so, differences in the observed brightness between individual supernovae of this type simply reflect their different distances. This, and the fact that the peak brightness of these supernovae rivals that of their parent galaxy, has allowed to measure distances of even very remote galaxies . Some apparent discrepancies that were recently found have led to the discovery of cosmic acceleration . However, this first clearcut observation of explosion asymmetry in a Type Ia supernova means that the exact brightness of such an object will depend on the angle from which it is seen. Since this angle is unknown for any particular supernova, this obviously introduces an amount of uncertainty into this kind of basic distance measurements in the Universe which must be taken into account in the future. Fortunately, the VLT data also show that if you wait a little - which in observational terms makes it possible to look deeper into the expanding fireball - then it becomes more spherical. Distance determinations of supernovae that are performed at this later stage will therefore be more accurate. PR Photo 24a/03 : Spiral galaxy NGC

  4. MOONS: A New Powerful Multi-Object Spectrograph for the VLT

    Science.gov (United States)

    Cirasuolo, M.; MOONS Consortium

    2016-10-01

    MOONS (the Multi-Object Optical and Near-infrared Spectrograph) is a third-generation instrument for the ESO Very Large Telescope (VLT). The large collecting area offered by the VLT (8.2 m diameter), combined with the large multiplex and wavelength coverage (optical to near-IR: 0.64 μm - 1.8 μm) of MOONS will provide the European astronomical community with a powerful, unique instrument able to pioneer a wide range of Galactic, Extragalactic and Cosmological studies, and the crucial follow-up for major facilities such as Gaia, VISTA, Euclid and LSST. MOONS has the observational power needed to unveil galaxy formation and evolution over the entire history of the Universe, from stars in our Milky Way, through the redshift desert, and up to the epoch of the very first galaxies and reionization of the Universe at redshifts of z > 8-9, just a few million years after the Big Bang. From five years of observations MOONS will provide high-quality spectra for >3 M stars in our Galaxy and the Local Group, and for 1-2 M galaxies at z >1 (for an SDSS-like survey), promising to revolutionize our understanding of the Universe. The baseline design consists of 1024 fibers, deployable over a field-of-view of ˜500 sq. arcmin, the largest patrol field offered by the Nasmyth focus at the VLT. The total wavelength coverage is 0.64 μm - 1.8 μm with two spectral resolving power settings: in the medium-resolution mode (R˜4,000-6,000) the entire wavelength range is observed simultaneously, while the high-resolution mode will cover simultaneously selected sub-regions: one region with R˜9,000 near the Ca II triplet to measure stellar radial velocities, and part of the H-band at R˜20,000 for precision measurements of chemical abundances.

  5. Polarimetry in Planetary Science—A Step Forward with the VLT and a Need for the ELTs

    Science.gov (United States)

    Boehnhardt, H.; Tozzi, G. P.; Sterzik, M.; Bagnulo, S.; Kolokolova, L.; Muinonen, K.

    2009-09-01

    We present a brief review of polarimetric measurements of solar system objects, both linear and circular, obtained with the FORS1 instrument at the Very Large Telescope VLT over the past years. A number of first and new results have been obtained by using this unique observing mode at an 8 m class telescope, among them polarimetry of faint planetary bodies like near-Earth asteroids, Kuiper Belt objects and cometary nuclei, spectropolarimetry of cometary coma material and of the Earthshine of the Moon (in order to verify that life exists on Earth!). We outline the science cases for planetary polarimetry at a future Extremely Large Telescope ELT and provide high level requirements for polarimetric equipment to be used at the ELTs for the study of the science cases described.

  6. Neutrino telescopes

    CERN Document Server

    Carr, J

    2002-01-01

    This review presents the scientific objectives and status of Neutrino Telescope Projects. The science program of these projects covers: neutrino astronomy, dark matter searches and measurements of neutrino oscillations. The two neutrino telescopes in operation: AMANDA and BAIKAL will be described together with the ANTARES neutrino telescope being built in the Mediterranean. (18 refs).

  7. Space Telescopes

    Science.gov (United States)

    2010-01-01

    Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 166 9. Space telescopes Figure 9.1: Paraboloid telescope. In the following sections, NI...planets nearby a brighter star. Normal-incidence telescopes One-mirror telescope The one-mirror telescope (mostly an off-axis paraboloid ; Figure 9.1) has...rotation of the whole instrument (see SUMER/SOHO, Wilhelm et al (1995) and EIS/Hinode, Culhane et al (2007)). The paraboloid field curvature (Petzval

  8. VLT spectroscopy of NGC3115 globular clusters

    CERN Document Server

    Kuntschner, H; Sharples, R M; Worthey, G; Fricke, K J; Kuntschner, Harald; Ziegler, Bodo L.; Worthey, Guy; Fricke, Klaus J.

    2002-01-01

    We present results derived from VLT-FORS2 spectra of 24 different globular clusters associated with the lenticular galaxy NGC3115. A subsample of 17 globular clusters have sufficiently high signal-to-noise to allow precision measurements of absorption line-strengths. Comparing these indices to new stellar population models by Thomas et al. we determine ages, metallicities and element abundance ratios. Our data are also compared with the Lick/IDS observations of Milky Way and M31 globular clusters. Unpublished higher order Balmer lines (HgammaA,F and HdeltaA,F) from the Lick/IDS observations are given in the Appendix. Our best age estimates show that the observed clusters which sample the bimodal colour distribution of NGC3115 are coeval within our observational errors (2-3 Gyr). Our best calibrated age/metallicity diagnostic diagram (Hbeta vs [MgFe]) indicates an absolute age of 11-12 Gyr. We confirm with our accurate line-strength measurements that the (V-I) colour is a good metallicity indicator within the ...

  9. The VLT Unravels the Nature of the Fastest Binary Star

    Science.gov (United States)

    2002-03-01

    Two Hot White Dwarfs Perform a Tight Dance Summary Observations with ESO's Very Large Telescope (VLT) in Chile and the Italian Telescopio Nazionale Galileo (TNG) on the Canary Islands during the past two years have enabled an international group of astronomers [1] to unravel the true nature of an exceptional binary stellar system. This system, designated RX J0806.3+1527 , was first discovered as an X-ray source of variable brightness - once every five minutes, it "switches off" for a short moment. The new observations have shown beyond doubt that this period reflects the orbital motion of two "white dwarf" stars that revolve around each other at a distance of only 80,000 km . Each of the stars is about as large as the Earth and this is the shortest orbital period known for any binary stellar system. The VLT spectrum displays lines of ionized helium, indicating that the presence of an exceedingly hot area on one of the stars - a "hot spot" with a temperature of approx. 250,000 degrees. The system is currently in a rarely seen, transitory evolutionary state . PR Photo 10a/02 : U- and R-band images of RX J0806.3+1527. PR Photo 10b/02 : Spectrum of RX J0806.3+1527 An amazing stellar binary system ESO PR Photo 10a/02 ESO PR Photo 10a/02 [Preview - JPEG: 800 x 400 pix - 440k] [Normal - JPEG: 1600 x 800 pix - 1.1M] Caption : PR Photo 10a/02 shows U and R filter images of the sky field around RX J0806.3+1527 (at centre of circle), obtained with the FORS2 multi-mode instrument on VLT KUEYEN. The object is brightest at the shorter wavelength (U-band) - reflecting its very high temperature. Technical information about the photo is available below. One year is the time it takes the Earth to move once around the Sun, our central star. This may seem quite fast when measured on the scale of the Universe, but this is a snail's motion compared to the the speed of two recently discovered stars. They revolve around each other 100,000 times faster; one full revolution takes only 321

  10. Status and new operation modes of the versatile VLT/NACO

    CERN Document Server

    Girard, Julien H V; Quanz, Sascha P; Kenworthy, Matthew A; Rengaswamy, Sridharan; Schödel, Rainer; Gallenne, Alexandre; Gillessen, Stefan; Huerta, Nicolas; Kervella, Pierre; Kornweibel, Nick; Lenzen, Rainer; Mérand, Antoine; Montagnier, Guillaume; O'Neal, Jared; Zins, Gérard; IOT, the NACO; 10.1117/12.856799

    2010-01-01

    This paper aims at giving an update on the most versatile adaptive optics fed instrument to date, the well known and successful NACO . Although NACO is only scheduled for about two more years at the Very Large Telescope (VLT), it keeps on evolving with additional operation modes bringing original astronomical results. The high contrast imaging community uses it creatively as a test-bench for SPHERE and other second generation planet imagers. A new visible wavefront sensor (WFS) optimized for Laser Guide Star (LGS) operations has been installed and tested, the cube mode is more and more requested for frame selection on bright sources, a seeing enhancer mode (no tip/tilt correction) is now offered to provide full sky coverage and welcome all kind of extragalactic applications, etc. The Instrument Operations Team (IOT) and Paranal engineers are currently working hard at maintaining the instrument overall performances but also at improving them and offering new capabilities, providing the community with a well tu...

  11. The DAG project, a 4m class telescope: the telescope main structure performances

    Science.gov (United States)

    Marchiori, G.; Busatta, A.; Ghedin, L.; Marcuzzi, E.; Manfrin, C.; Battistel, C.; Pirnay, O.; Flebus, Carlo; Yeşilyaprak, C.; Keskin, O.; Yerli, S.

    2016-07-01

    Dogu Anatolu Gözlemevi (DAG-Eastern Anatolia Observatory) Project is a 4m class optical, near-infrared Telescope and suitable enclosure which will be located at an altitude of 3.170m in Erzurum, Turkey. The DAG telescope is a project fully funded by Turkish Ministry of Development and the Atatürk University of Astrophysics Research Telescope - ATASAM. The Project is being developed by the Belgian company AMOS (project leader), which is also the optics supplier and EIE GROUP, the Telescope Main Structure supplier and responsible for the final site integration. The design of the Telescope Main Structure fits in the EIE TBO Program which aims at developing a Dome/Telescope systemic optimization process for both performances and competitive costs based on previous project commitments like NTT, VLT, VST and ASTRI. The optical Configuration of the DAG Telescope is a Ritchey-Chretien with two Nasmyth foci and a 4m primary thin mirror controlled in shape and position by an Active Optic System. The main characteristics of the Telescope Main Structure are an Altitude-Azimuth light and rigid structure system with Direct Drive Systems for both axis, AZ Hydrostatic Bearing System and Altitude standard bearing system; both axes are equipped with Tape Encoder System. An innovative Control System characterizes the telescope performance.

  12. VLT/UVES constraints on the cosmological variability of the fine-structure constant

    Science.gov (United States)

    Levshakov, S. A.; Centurión, M.; Molaro, P.; D'Odorico, S.

    2005-05-01

    We propose a new methodology for probing the cosmological variability of α from pairs of Fe II lines (SIDAM, single ion differential α measurement) observed in individual exposures from a high resolution spectrograph. By this we avoid the influence of the spectral shifts due to (i) ionization inhomogeneities in the absorbers; and (ii) non-zero offsets between different exposures. Applied to the Fe II lines of the metal absorption line system at z_abs = 1.839 in the spectrum of Q 1101-264 obtained by means of the UV-Visual Echelle Spectrograph (UVES) at the ESO Very Large Telescope (VLT), SIDAM provides Δα/α = (2.4±3.8_stat)×10-6. The z_abs = 1.15 Fe II system toward HE 0515-4414 has been re-analyzed by this method thus obtaining for the combined sample Δα/α = (0.4±1.5_stat)×10-6. These values are shifted with respect to the Keck/HIRES mean Δα/α = (-5.7 ± 1.1_stat)×10-6 (Murphy et al. 2004) at very high confidence level (95%). The fundamental photon noise limitation in the Δα/α measurement with the VLT/UVES is discussed to figure the prospects for future observations. It is suggested that with a spectrograph of ~10 times the UVES dispersion coupled to a 100 m class telescope the present Oklo level (Δα/α ≥ 4.5 × 10-8) can be achieved along cosmological distances with differential measurements of Δα/α.

  13. VLT/SPHERE deep insight of NGC 3603's core: Segregation or confusion?

    CERN Document Server

    Khorrami, Z; Vakili, F; Lagadec, E; Langlois, M; Brandner, W; Chesneau, O; Meyer, M R; Carbillet, M; Abe, L; Mouillet, D; Beuzit, JL; Boccaletti, A; Perrot, C; Thalmann, C; Schmid, H -M; Pavlov, A; Costille, A; Dohlen, K; Mignant, D Le; Petit, C; Sauvage, J F

    2016-01-01

    We present new near-infrared photometric measurements of the core of the young massive cluster NGC 3603 obtained with extreme adaptive optics. The data were obtained with the SPHERE instrument mounted on ESO Very Large Telescope, and cover three fields in the core of this cluster. We applied a correction for the effect of extinction to our data obtained in the J and K broadband filters and estimated the mass of detected sources inside the field of view of SPHERE/IRDIS, which is 13.5"x13.5". We derived the mass function (MF) slope for each spectral band and field. The MF slope in the core is unusual compared to previous results based on Hubble space telescope (HST) and very large telescope (VLT) observations. The average slope in the core is estimated as -1.06^{+0.26}_{-0.26} for the main sequence stars with 3.5 Msun < M < 120 Msun.Thanks to the SPHERE extreme adaptive optics, 814 low-mass stars were detected to estimate the MF slope for the pre-main sequence stars with 0.6 Msun< M < 3.5 Msun , Gam...

  14. Surface composition of Europa based on VLT observations

    Science.gov (United States)

    Ligier, N.; Poulet, F.; Carter, J.

    2016-12-01

    Jupiter's moon Europa may harbor a global salty ocean under an 80-170 km thick outer layer consisting of an icy crust (Anderson et al. 1998). Meanwhile, the 10-50 My old surface, dated by cratering rates (Pappalardo et al. 1999) implies rapid surface recycling and reprocessing that could result in tectonic activity (Kattenhorn et al. 2014) and plumes (Roth et al. 2014). The surface could thus exhibit fingerprints of chemical species, as minerals characteristics of an ocean-mantle interaction and/or organics of exobiological interest, directly originating from the subglacial ocean. In order to re-investigate the composition of Europa's surface, a global mapping campaign of the satellite was performed with the near-infrared integral field spectrograph SINFONI on the Very Large Telescope (VLT) in Chile. The high spectral binning of this instrument (0.5 nm) and large signal noise ratio in comparison to previous observations are adequate to detect sharp absorptions in the wavelength range 1.45-2.45 μm. In addition, the spatially resolved spectra we obtained over five epochs nearly cover the entire surface of Europa with a pixel scale of 12.5 by 25 m.a.s ( 35 by 70 km on Europa's surface), thus permitting a global scale study. Several icy and non-icy compounds were detected and mapped at process likely engendered by the Io plasma torus, the crystalline form is found to be approximately twice as abundant as the amorphous ice based on the analysis of the 1.65 μm band. If the surface is dominated by small and mid-sized water ice grains (25-200 μm), crystalline water-ice grains exhibit spatial inhomogeneities in their distribution. The sulfuric acid hydrate distribution exhibits the typical "bullseye" feature on the trailing hemisphere. The presence of Mg-bearing chlorinated salts (chloride, chlorate, and perchlorate) is supported by linear spectral modeling of the data, while the presence of sulfate salts is challenged. The distribution of some of these species is

  15. Saturn's Doppler velocimetry wind measurements with VLT/UVES

    Science.gov (United States)

    Silva, Miguel; Mota Machado, Pedro; Luz, David; Sanchez-Lavega, Agustin; Hueso, Ricardo; Peralta, Javier

    2016-10-01

    We present Doppler wind velocity results of Saturn's zonal flow at ~0.4 mbar pressure level. Our aim is help to constrain the characterization of the equatorial jet at the referred altitude and the latitudinal variation of the zonal winds, to contribute to monitor the spatial and temporal variability in order to achieve a better understanding of the dynamics of Saturn's zonal winds, which Sánchez-Lavega et al. (2003, Nature, 423, 623) have found to have strongly changed in recent years, as the planet approached southern summer solstice.The UVES/VLT instrument has been used, which simultaneously achieves high spectral resolving power and high spatial resolution. The field has been derotated in order to have the aperture aligned perpendicularly to Saturn's rotation axis. In this configuration, spatial information in the East-West direction is preserved in a set of spectra in the direction perpendicular to dispersion.The technique of absolute accelerometry (AA, Connes, 1985, ApSS 110, 211) has been applied to the backscattered solar spectrum in order to determine the Doppler shift associated with the zonal circulation. Our measurements have been made in the wavelength range of 480-680 nm. Previously we successfully adapted this Doppler velocimetry technique for measuring winds at Venus cloud tops (Machado et al. 2012).The observations consisted of 4 blocks of 15 exposures of 90 sec, plus two shorter blocks of 9 exposures, totalling 7.3 hours of telescope time. In order to cover the whole disk the aperture has been offset by 1 arcsec in the North-South direction between consecutive exposures. Most of the northern hemisphere was covered by the rings. Saturn's diameter was 17.4 arcsec, and the slit aperture was 0.3x25 arcsec. The aperture offset between consecutive exposures was 1 arcsec. Two observations blocks of 9 exposures only covered the central part of the disk, and four others covered the whole disk. The sub-terrestrial point was at -26.1 degrees South. The

  16. VLT beryllium secondary mirror no. 1: performance review

    Science.gov (United States)

    Cayrel, Marc

    1998-08-01

    The four Very Large Telescope secondary mirrors are 1.2-m Beryllium lightweight convex mirrors. REOSC has been selected for the design and manufacturing of the optics and of their supporting system. The first mirror unit has been delivered in September, 1997. Operating from visible to near infrared, the mirror defines the telescope aperture stop and may be chopped during observation. The optical requirements are tight and a high stiffness, low weight and inertia are requested as well. Using beryllium is a technical challenge for such a large optic manufacturing, in particular regarding its stability. The requirements and design are presented, we review the mirror manufacturing steps: blank production, machining, grinding, Nickel plating, polishing, integration and testing. The optical quality control method, a problem for large convex mirrors control, is detailed. The results of acceptance testing of mirror No. 1 are summarized, we present conclusions about the mirror figure stability. The status of the three additional mirrors manufacturing is presented to conclude.

  17. Configurable slit-mask unit of the Multi-Object Spectrometer for Infra-Red Exploration for the Keck telescope: integration and tests

    Science.gov (United States)

    Spanoudakis, Peter; Giriens, Laurent; Henein, Simon; Lisowski, Leszek; O'Hare, Aidan; Onillon, Emmanuel; Schwab, Philippe; Theurillat, Patrick

    2008-07-01

    A Configurable Slit Unit (CSU) has been developed for the Multi-Object Spectrometer for Infra-Red Exploration (MOSFIRE) instrument to be installed on the Keck 1 Telescope on Mauna Kea, Hawaii. MOSFIRE will provide NIR multi-object spectroscopy over a field of view of 6.1' x 6.1'. The reconfigurable mask allows the formation of 46 optical slits in a 267 x 267 mm2 field of view. The mechanism is an evolution of a former prototype designed by CSEM and qualified for the European Space Agency (ESA) as a candidate for the slit mask on NIRSpec for the James Webb Space Telescope (JWST). The CSU is designed to simultaneously displace masking bars across the field-of-view (FOV) to mask unwanted light. A set of 46 bar pairs are used to form the MOSFIRE focal plane mask. The sides of the bars are convoluted so that light is prevented from passing between adjacent bars. The slit length is fixed (5.1 mm) but the width is variable down to 200 μm with a slit positioning accuracy of +/- 18 μm. A two-bar prototype mechanism was designed, manufactured and cryogenically tested to validate the modifications from the JWST prototype. The working principle of the mechanism is based on an improved "inch-worm" stepping motion of 92 masking bars forming the optical mask. Original voice coil actuators are used to drive the various clutches. The design makes significant use of flexure structures.

  18. HST/WFC3 observations of Uranus' 2014 storm clouds and comparison with VLT/SINFONI and IRTF/Spex observations

    Science.gov (United States)

    Irwin, Patrick G. J.; Wong, Michael H.; Simon, Amy A.; Orton, G. S.; Toledo, Daniel

    2017-05-01

    In November 2014 Uranus was observed with the Wide Field Camera 3 (WFC3) instrument of the Hubble Space Telescope as part of the Hubble 2020: Outer Planet Atmospheres Legacy program, OPAL. OPAL annually maps Jupiter, Uranus and Neptune (and will also map Saturn from 2018) in several visible/near-infrared wavelength filters. The Uranus 2014 OPAL observations were made on the 8/9th November at a time when a huge cloud complex, first observed by de Pater et al. (2015) and subsequently tracked by professional and amateur astronomers (Sayanagi et al., 2016), was present at 30-40°N. We imaged the entire visible atmosphere, including the storm system, in seven filters spanning 467-924 nm, capturing variations in the coloration of Uranus' clouds and also vertical distribution due to wavelength dependent changes in Rayleigh scattering and methane absorption optical depth. Here we analyse these new HST observations with the NEMESIS radiative-transfer and retrieval code in multiple-scattering mode to determine the vertical cloud structure in and around the storm cloud system. The same storm system was also observed in the H-band (1.4-1.8 μm) with the SINFONI Integral Field Unit Spectrometer on the Very Large Telescope (VLT) on 31st October and 11th November, reported by Irwin et al. (2016, 10.1016/j.icarus.2015.09.010). To constrain better the cloud particle sizes and scattering properties over a wide wavelength range we also conducted a limb-darkening analysis of the background cloud structure in the 30-40°N latitude band by simultaneously fitting: a) these HST/OPAL observations at a range of zenith angles; b) the VLT/SINFONI observations at a range of zenith angles; and c) IRTF/SpeX observations of this latitude band made in 2009 at a single zenith angle of 23°, spanning the wavelength range 0.8-1.8 μm (Irwin et al., 2015, 10.1016/j.icarus.2014.12.020). We find that the HST observations, and the combined HST/VLT/IRTF observations at all locations are well modelled with

  19. VLT FORS2 comparative transmission spectroscopy: Detection of Na in the atmosphere of WASP-39b from the ground

    CERN Document Server

    Nikolov, Nikolay; Gibson, Neale P; Fortney, J J; Evans, Thomas M; Barstow, Joanna K; Kataria, Tiffany; Wilson, Paul A

    2016-01-01

    We present transmission spectroscopy of the warm Saturn-mass exoplanet WASP-39b made with the Very Large Telescope (VLT) FOcal Reducer and Spectrograph (FORS2) across the wavelength range 411-810nm. The transit depth is measured with a typical precision of 240 parts per million (ppm) in wavelength bins of 10nm on a V = 12.1 magnitude star. We detect the sodium absorption feature (3.2-sigma) and find evidence for potassium. The ground-based transmission spectrum is consistent with Hubble Space Telescope (HST) optical spectroscopy, strengthening the interpretation of WASP-39b having a largely clear atmosphere. Our results demonstrate the great potential of the recently upgraded FORS2 spectrograph for optical transmission spectroscopy, obtaining HST-quality light curves from the ground.

  20. Design of the ERIS calibration unit

    Science.gov (United States)

    Dolci, Mauro; Valentini, Angelo; Di Rico, Gianluca; Esposito, Simone; Ferruzzi, Debora; Riccardi, Armando; Spanò, Paolo; Antichi, Jacopo

    2016-08-01

    The Enhanced Resolution Imager and Spectrograph (ERIS) is a new-generation instrument for the Cassegrain focus of the ESO UT4/VLT, aimed at performing AO-assisted imaging and medium resolution spectroscopy in the 1-5 micron wavelength range. ERIS consists of the 1-5 micron imaging camera NIX, the 1-2.5 micron integral field spectrograph SPIFFIER (a modified version of SPIFFI, currently operating on SINFONI), the AO module and the internal Calibration Unit (ERIS CU). The purpose of this unit is to provide facilities to calibrate the scientific instruments in the 1-2.5 micron and to perform troubleshooting and periodic maintenance tests of the AO module (e.g. NGS and LGS WFS internal calibrations and functionalities, ERIS differential flexures) in the 0.5 - 1 μm range. The ERIS CU must therefore be designed in order to provide, over the full 0.5 - 2.5 μm range, the following capabilities: 1) illumination of both the telescope focal plane and the telescope pupil with a high-degree of uniformity; 2) artificial point-like and extended sources onto the telescope focal plane, with high accuracy in both positioning and FWHM; 3) wavelength calibration; 4) high stability of these characteristics. In this paper the design of the ERIS CU, and the solutions adopted to fulfill all these requirements, is described. The ERIS CU construction is foreseen to start at the end of 2016.

  1. X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope

    DEFF Research Database (Denmark)

    Vernet, J.; Dekker, H.; D'Odorico, S.

    2011-01-01

    X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope (VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 t...

  2. X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope

    NARCIS (Netherlands)

    Vernet, J.; Dekker, H.; D'Odorico, S.; Kaper, L.; Kjaergaard, P.; Hammer, F.; Randich, S.; Zerbi, F.; Groot, P.J.; Hjorth, J.; Guinouard, I.; Navarro, R.; Adolfse, T.; Albers, P.W.; Amans, J.-P.; Andersen, J.J.; Andersen, M.I.; Binetruy, P.; Bristow, P.; Castillo, R.; Chemla, F.; Christensen, L.; Conconi, P.; Conzelmann, R.; Dam, J.; De Caprio, V.; de Ugarte Postigo, A.; Delabre, B.; Di Marcantonio, P.; Downing, M.; Elswijk, E.; Finger, G.; Fischer, G.; Flores, H.; François, P.; Goldoni, P.; Guglielmi, L.; Haigron, R.; Hanenburg, H.; Hendriks, I.; Horrobin, M.; Horville, D.; Jessen, N.C.; Kerber, F.; Kern, L.; Kiekebusch, M.; Kleszcz, P.; Klougart, J.; Kragt, J.; Larsen, H.H.; Lizon, J.-L.; Lucuix, C.; Mainieri, V.; Manuputy, R.; Martayan, C.; Mason, E.; Mazzoleni, R.; Michaelsen, N.; Modigliani, A.; Moehler, S.; Møller, P.; Norup Sørensen, A.; Nørregaard, P.; Péroux, C.; Patat, F.; Pena, E.; Pragt, J.; Reinero, C.; Rigal, F.; Riva, M.; Roelfsema, R.; Royer, F.; Sacco, G.; Santin, P.; Schoenmaker, T.; Spano, P.; Sweers, E.; ter Horst, R.; Tintori, M.; Tromp, N.; van Dael, P.; van Vliet, H.; Venema, L.; Vidali, M.; Vinther, J.; Vola, P.; Winters, R.; Wistisen, D.; Wulterkens, G.; Zacchei, A.

    2011-01-01

    X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope (VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 to

  3. Design and development of control unit and software for the ADFOSC instrument of the 3.6 m Devasthal optical telescope

    Science.gov (United States)

    Kumar, T. S.

    2016-08-01

    In this paper, we describe the details of control unit and GUI software for positioning two filter wheels, a slit wheel and a grism wheel in the ADFOSC instrument. This is a first generation instrument being built for the 3.6 m Devasthal optical telescope. The control hardware consists of five electronic boards based on low cost 8-bit PIC microcontrollers and are distributed over I2C bus. The four wheels are controlled by four identical boards which are configured in I2C slave mode while the fifth board acts as an I2C master for sending commands to and receiving status from the slave boards. The master also communicates with the interfacing PC over TCP/IP protocol using simple ASCII commands. For moving the wheels stepper motors along with suitable amplifiers have been employed. Homing after powering ON is achieved using hall effect sensors. By implementing distributed control units having identical design modularity is achieved enabling easier maintenance and upgradation. A GUI based software for commanding the instrument is developed in Microsoft Visual C++. For operating the system during observations the user selects normal mode while the engineering mode is available for offering additional flexibility and low level control during maintenance and testing. A detailed time-stamped log of commands, status and errors are continuously generated. Both the control unit and the software have been successfully tested and integrated with the ADFOSC instrument.

  4. PC based PLCs and ethernet based fieldbus: the new standard platform for future VLT instrument control

    Science.gov (United States)

    Kiekebusch, Mario J.; Lucuix, Christian; Erm, Toomas M.; Chiozzi, Gianluca; Zamparelli, Michele; Kern, Lothar; Brast, Roland; Pirani, Werther; Reiss, Roland; Popovic, Dan; Knudstrup, Jens; Duchateau, Michel; Sandrock, Stefan; Di Lieto, Nicola

    2014-07-01

    ESO is currently in the final phase of the standardization process for PC-based Programmable Logical Controllers (PLCs) as the new platform for the development of control systems for future VLT/VLTI instruments. The standard solution used until now consists of a Local Control Unit (LCU), a VME-based system having a CPU and commercial and proprietary boards. This system includes several layers of software and many thousands of lines of code developed and maintained in house. LCUs have been used for several years as the interface to control instrument functions but now are being replaced by commercial off-the-shelf (COTS) systems based on BECKHOFF Embedded PCs and the EtherCAT fieldbus. ESO is working on the completion of the software framework that enables a seamless integration into the VLT control system in order to be ready to support upcoming instruments like ESPRESSO and ERIS, that will be the first fully VLT compliant instruments using the new standard. The technology evaluation and standardization process has been a long and combined effort of various engineering disciplines like electronics, control and software, working together to define a solution that meets the requirements and minimizes the impact on the observatory operations and maintenance. This paper presents the challenges of the standardization process and the steps involved in such a change. It provides a technical overview of how industrial standards like EtherCAT, OPC-UA, PLCOpen MC and TwinCAT can be used to replace LCU features in various areas like software engineering and programming languages, motion control, time synchronization and astronomical tracking.

  5. MEGARA optical design: the new integral field unit and multi-object spectrograph for the GTC 10m telescope

    Science.gov (United States)

    García-Vargas, María. Luisa; Sánchez-Blanco, Ernesto; Carrasco, Esperanza; Gil de Paz, Armando; Páez, Gonzalo; Pérez, Ana; Gallego, Jesús; Sánchez, Francisco; Vílchez, José M.

    2012-12-01

    We describe the optical design of MEGARA, the future optical Integral Field Unit (IFU) and Multi-Object Spectrograph (MOS) for the 10.4-m Gran Telescopio CANARIAS (GTC). MEGARA is being built by a Consortium of public research institutions led by the Universidad Complutense de Madrid (UCM, Spain) that also includes INAOE (Mexico), IAA-CSIC (Spain) and UPM (Spain).

  6. SPHERE: A Planet Finder Instrument for the VLT

    NARCIS (Netherlands)

    Beuzit, J.L.; Feldt, M.; Dohlen, K.; Mouillet, D.; Puget, P.; Antichi, J.; Baudoz, P.; Boccaletti, A.; Carbillet, M.; Charton, J.; Claudi, R.; Fusco, T.; Gratton, R.; Henning, T.; Hubin, N.; Joos, F.; Kasper, M.; Langlois, M.; Moutou, C.; Pragt, J.; Rabou, P.; Saisse, M.; Schmid, H.M.; Turatto, M.; Udry, S.; Vakili, F.; Waters, R.; Wildi, F.

    2007-01-01

    Direct detection and spectral characterization of extra-solar planets is one of the most exciting but also one of the most challenging areas in modern astronomy. For its second generation instrumentation on the VLT, ESO has supported two phase A studies for a so-called Planet Finder dedicated instru

  7. The science case of the CHEOPS planet finder for VLT

    NARCIS (Netherlands)

    Gratton, R.; Feldt, M.; Schmid, H.M.; Brandner, W.; Hippler, S.; Neuhauser, R.; Quirrenbach, A.; Desidera, S.; Turatto, M.; Stam, D.M.; Hasinger, G.; Turner, M.J.L.

    2004-01-01

    The CHEOPS Planet Finder is one of the proposed second generation instruments for the VLT. Its purpose is to image and characterize giant extrasolar planets in different phases of their evolution: young, warm planets as well as old, cold ones. Imaging the last ones is the most challenging task becau

  8. SNAP telescope

    Energy Technology Data Exchange (ETDEWEB)

    Lampton, Michael L.; Akerlof, C.W.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E.; Bebek, C.; Bergstrom, L.; Bercovitz, J.; Bernstein, G.; Bester, M.; Bonissent, A.; Bower, C.; Carithers Jr., W.C.; Commins, E.D.; Day, C.; Deustua, S.E.; DiGennaro, R.; Ealet, A.; Ellis,R.S.; Eriksson, M.; Fruchter, A.; Genat, J.-F.; Goldhaber, G.; Goobar,A.; Groom, D.; Harris, S.E.; Harvey, P.R.; Heetderks, H.D.; Holland,S.E.; Huterer, D.; Karcher, A.; Kim, A.G.; Kolbe, W.; Krieger, B.; Lafever, R.; Lamoureux, J.; Levi, M.E.; Levin, D.S.; Linder, E.V.; Loken,S.C.; Malina, R.; Massey, R.; McKay, T.; McKee, S.P.; Miquel, R.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi,H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Pratt, R.; Prieto,E.; Refregier, A.; Rhodes, J.; Robinson, K.; Roe, N.; Sholl, M.; Schubnell, M.; Smadja, G.; Smoot, G.; Spadafora, A.; Tarle, G.; Tomasch,A.; von der Lippe, H.; Vincent, R.; Walder, J.-P.; Wang, G.; Wang, G.

    2002-07-29

    The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applications such as SNAP, and describe the features of the specific optical configuration that we have baselined for the SNAP mission. We discuss the mechanical design and choice of materials for the telescope. Then we present detailed ray traces and diffraction calculations for our baseline optical design. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of tasks to be carried out during the upcoming SNAP research and development phase.

  9. Direct exoplanet detection and characterization using the ANDROMEDA method: Performance on VLT/NaCo data

    Science.gov (United States)

    Cantalloube, F.; Mouillet, D.; Mugnier, L. M.; Milli, J.; Absil, O.; Gomez Gonzalez, C. A.; Chauvin, G.; Beuzit, J.-L.; Cornia, A.

    2015-10-01

    Context. The direct detection of exoplanets with high-contrast imaging requires advanced data processing methods to disentangle potential planetary signals from bright quasi-static speckles. Among them, angular differential imaging (ADI) permits potential planetary signals with a known rotation rate to be separated from instrumental speckles that are either statics or slowly variable. The method presented in this paper, called ANDROMEDA for ANgular Differential OptiMal Exoplanet Detection Algorithm, is based on a maximum likelihood approach to ADI and is used to estimate the position and the flux of any point source present in the field of view. Aims: In order to optimize and experimentally validate this previously proposed method, we applied ANDROMEDA to real VLT/NaCo data. In addition to its pure detection capability, we investigated the possibility of defining simple and efficient criteria for automatic point source extraction able to support the processing of large surveys. Methods: To assess the performance of the method, we applied ANDROMEDA on VLT/NaCo data of TYC-8979-1683-1 which is surrounded by numerous bright stars and on which we added synthetic planets of known position and flux in the field. In order to accommodate the real data properties, it was necessary to develop additional pre-processing and post-processing steps to the initially proposed algorithm. We then investigated its skill in the challenging case of a well-known target, β Pictoris, whose companion is close to the detection limit and we compared our results to those obtained by another method based on principal component analysis (PCA). Results: Application on VLT/NaCo data demonstrates the ability of ANDROMEDA to automatically detect and characterize point sources present in the image field. We end up with a robust method bringing consistent results with a sensitivity similar to the recently published algorithms, with only two parameters to be fine tuned. Moreover, the companion flux

  10. CROMOS A cryogenic near-infrared, multi-object spectrometer for the VLT

    CERN Document Server

    Genzel, R; Tomono, D; Thatte, N; Eisenhauer, F; Lehnert, M; Tecza, M; Bender, R

    2001-01-01

    We discuss a cryogenic, multi-object near-infrared spectrometer as a second generation instrument for the VLT. The spectrometer combines 20 to 40 independent integral eld units (IFUs), which can be positioned by a cryogenic robot over the entire unvignetted eld of the VLT (~7'). Each IFU consists of a contiguous cluster of 20 to 30 pixels (0.15 to 0.25" per pixel). The individual IFUs have cold fore-optics and couple into the spectrograph with integrated bers-microlenses. The spectrometer has lambda/d-lambda~4000 and simultaneously covers the J-, H-, and K-bands with three HAWAII 2 detectors. The system is designed for operation both in seeing limited and MCAO modes. Its speed is approximately 3500 times greater than that of ISAAC and 60 times greater than NIRMOS (in H-band). The proposed instrument aims at a wide range of science, ranging from studies of galaxies/clusters in the high-z Universe (dynamics and star formation in z>1 galaxies, evolution of ellipticals, properties of distant, obscured far-IR and ...

  11. Probing unexplored territories with MUSE: a second generation instrument for the VLT

    CERN Document Server

    Bacon, R; Böhm, P; Boudon, D; Brau-Nogue, S; Caillier, P; Capoani, L; Carollo, C M; Champavert, N; Contini, T; Daguise, E; Dalle, D; Delabre, B; Devriendt, J; Dreizler, S; Du Bois, J; Dupieux, M; Dupin, J P; Emsellem, E; Ferruit, P; Franx, M; Gallou, G; Gerssen, J; Guiderdoni, B; Hahn, T; Hofmann, D; Jarno, A; Kelz, A; Köhler, C; Kollatschny, W; Kosmalski, J; Laurent, F; Lilly, S J; Lizon, J; Loupias, M; Lynn, S; Manescau, A; McDermid, R M; Monstein, C; Nicklas, H; Pares, L; Pasquini, L; Pecontal-Rousset, A; Pécontal, E; Pellò, R; Petit, C; Picat, J P; Popow, E; Quirrenbach, Andreas G; Reiss, R; Renault, E; Roth, M; Schaye, J; Soucail, G; Steinmetz, M; Stroebele, S; Stuik, R; Weilbacher, P; Wozniak, H; De Zeeuw, P T

    2006-01-01

    The Multi Unit Spectroscopic Explorer (MUSE) is a second-generation VLT panoramic integral-field spectrograph under preliminary design study. MUSE has a field of 1x1 arcmin**2 sampled at 0.2x0.2 arcsec**2 and is assisted by the VLT ground layer adaptive optics ESO facility using four laser guide stars. The simultaneous spectral range is 465-930 nm, at a resolution of R~3000. MUSE couples the discovery potential of a large imaging device to the measuring capabilities of a high-quality spectrograph, while taking advantage of the increased spatial resolution provided by adaptive optics. This makes MUSE a unique and tremendously powerful instrument for discovering and characterizing objects that lie beyond the reach of even the deepest imaging surveys. MUSE has also a high spatial resolution mode with 7.5x7.5 arcsec**2 field of view sampled at 25 milli-arcsec. In this mode MUSE should be able to obtain diffraction limited data-cubes in the 600-930 nm wavelength range. Although the MUSE design has been optimized f...

  12. KOALA: a wide-field 1000 element integral-field unit for the Anglo-Australian Telescope

    Science.gov (United States)

    Ellis, S. C.; Ireland, M.; Lawrence, J. S.; Tims, J.; Staszak, N.; Brzeski, J.; Parker, Q. A.; Sharp, R.; Bland-Hawthorn, J.; Case, S.; Colless, M.; Croom, S.; Couch, W.; De Marco, O.; Glazebrook, K.; Saunders, W.; Webster, R.; Zucker, D. B.

    2012-09-01

    KOALA, the Kilofibre Optimised Astronomical Lenslet Array, is a wide-field, high efficiency integral field unit being designed for use with the bench mounted AAOmega spectrograph on the AAT. KOALA will have 1000 fibres in a rectangular array with a selectable field of view of either 1390 or 430 sq. arcseconds with a spatial sampling of 1.25" or 0.7" respectively. To achieve this KOALA will use a telecentric double lenslet array with interchangeable fore-optics. The IFU will feed AAOmega via a 31m fibre run. The efficiency of KOALA is expected to be ≍ 52% at 3700A and ≍ 66% at 6563°Å with a throughput of > 52% over the entire wavelength range.

  13. Ground-based astrometry with wide field imagers. V. Application to near-infrared detectors: HAWK-I@VLT/ESO

    Science.gov (United States)

    Libralato, M.; Bellini, A.; Bedin, L. R.; Piotto, G.; Platais, I.; Kissler-Patig, M.; Milone, A. P.

    2014-03-01

    High-precision astrometry requires accurate point-spread function modeling and accurate geometric-distortion corrections. This paper demonstrates that it is possible to achieve both requirements with data collected at the high acuity wide-field K-band imager (HAWK-I), a wide-field imager installed at the Nasmyth focus of UT4/VLT ESO 8 m telescope. Our final astrometric precision reaches ~3 mas per coordinate for a well-exposed star in a single image with a systematic error less than 0.1 mas. We constructed calibrated astro-photometric catalogs and atlases of seven fields: the Baade's window, NGC 6656, NGC 6121, NGC 6822, NGC 6388, NGC 104, and the James Webb Space Telescope calibration field (in the Large Magellanic Cloud). We make these catalogs and images electronically available to the community. Furthermore, as a demonstration of the efficacy of our approach, we combined archival material taken with the optical wide-field imager at the MPI/ESO 2.2 m with HAWK-I observations. We showed that we are able to achieve an excellent separation between cluster members and field objects for NGC 6656 and NGC 6121 with a time base-line of about 8 years. Using both HST and HAWK-I data, we also study the radial distribution of the SGB populations in NGC 6656 and conclude that the radial trend is flat within our uncertainty. We also provide membership probabilities for most of the stars in NGC 6656 and NGC 6121 catalogs and estimate membership for the published variable stars in these two fields. Catalogs, fortran code, and distortion maps are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/563/A80Based on observations with the 8 m VLT ESO telescope.

  14. The science case of WISH-Spec, an Integral-field unit for the WISH telescope to study the first populations of galaxies in the universe

    Science.gov (United States)

    Burgarella, Denis

    2015-08-01

    WISH is a new space science mission concept whose primary goal is to study the first galaxies in the early universe. WISH will be a 1.5m telescope equipped with a 1000 arcmin2 wide-field Near-IR camera that would fly in ~2020 in order to conduct unique ultra-deep and wide-area sky surveys in the wavelength range 1-5 micron. A spectroscopic mode (Integral-Field Unit) in the same Near-IR range is also planned. The primary science goal of WISH mission is to push the high-redshift frontier beyond the epoch of reionization by utilizing its unique imaging capability and the dedicated survey strategy. Which spectral range should we select to optimize the detection of very high-redshift (i.e., z > 5) galaxies ? In the rest-frame Far-UV or in the rest-frame Far-IR? In a recent paper, Burgarella et al. (2013) showed that the Far-UV dust attenuation (AFUV) reaches the same level at z ~ 3 than at z = 0 . This suggest that the early universe would be better studied in the rest-frame Far-UV. At z > 5, this Far-UV range moves into the Near-IR (1 - 5um) which is WISH’s preferred spectral range. The baseline of WISH-Spec is a 1x1 arcmin2 Integral-Field Unit (IFU) using slicers. WISH-Spec could observe in a parallel mode which translates into spectroscopic exposure times as long as the telescope lifetime. WISH features two 100-deg2 and 1000-deg2 surveys. However, WISHSpec will allow to acquire very large samples of high-redshift and primordial galaxies by combining spectroscopic detections within total (non contiguous) 1-deg2 and 10-deg2 fields of views. Therefore, the first strong advantage of WISHSpec wrt JWST is that 10^4 - 10^5 faint emission-line galaxies in 1 deg2 and 10^3 - 10^6 bright emission-line galaxies in 10 deg2 in the redshift range 3 < z < 8 will be detected.

  15. Quantification of non-LTE contributions to OH rotational temperatures based on VLT/X-shooter, VLT/UVES, and TIMED/SABER data

    Science.gov (United States)

    Noll, Stefan; Kausch, Wolfgang; Kimeswenger, Stefan; Proxauf, Bastian; Unterguggenberger, Stefanie; Jones, Amy M.

    2016-04-01

    The hydroxyl (OH) airglow emission is very valuable for estimating atmospheric temperatures at about 87 km because it is relatively easy to measure. The usual approach is based on intensity ratios of OH lines with low rotational upper levels of a given band and the assumption of a Boltzmann distribution of the level populations consistent with the ambient temperature. However, this assumption can be unrealistic if the frequency of thermalising collisions is too low, which is most likely at the highest emission altitudes. We have investigated the amounts of possible non-LTE contributions to the measured OH rotational temperatures depending on the selected lines, band, and time of observation. For this, we used several hundred spectra from the echelle spectrograph X-shooter at the Very Large Telescope (VLT) at Cerro Paranal in Chile. These data with a very wide wavelength coverage allowed us to simultaneously measure temperatures for 25 OH bands and two O2 bands. The latter were used to obtain reference temperatures, which is possible since the radiative lifetimes of the upper states are sufficiently long for establishing full thermalisation for the populations of the different rotational levels. For a comparison of the resulting temperatures, a correction of the different emission altitudes is required. Hence, we also used CO2-based temperature and OH and O2 emission profile data from the SABER multi-channel radiometer on the TIMED satellite. The altitude-corrected OH rotational temperatures show significant non-LTE effects for higher vibrational levels of the upper state v' and especially even v'. The maximum deviations of more than 10 K were found for v' = 8. The non-LTE effects can vary within a range of a few K. The studied nocturnal variations indicate that the non-LTE contributions increase when the emission layer rises. Finally, we will also present first results for several thousand spectra taken with the VLT high-resolution optical echelle spectrograph UVES

  16. Image quality and high contrast improvements on VLT/NACO

    CERN Document Server

    Girard, Julien H V; Mawet, Dimitri; Kasper, Markus; Zins, Gérard; Neichel, Benoît; Kolb, Johann; Christiaens, Valentin; Tourneboeuf, Martin; 10.1117/12.925660

    2012-01-01

    NACO is the famous and versatile diffraction limited NIR imager and spectrograph with which ESO celebrated 10 years of Adaptive Optics at the VLT. Since two years a substantial effort has been put in to understanding and fixing issues that directly affect the image quality and the high contrast performances of the instrument. Experiments to compensate the non-common-path aberrations and recover the highest possible Strehl ratios have been carried out successfully and a plan is hereafter described to perform such measurements regularly. The drift associated to pupil tracking since 2007 was fixed in October 2011. NACO is therefore even better suited for high contrast imaging and can be used with coronagraphic masks in the image plane. Some contrast measurements are shown and discussed. The work accomplished on NACO will serve as reference for the next generation instruments on the VLT, especially those working at the diffraction limit and making use of angular differential imaging (i.e. SPHERE, VISIR, possibly ...

  17. New BVRI photometry results on KBOs from the ESO VLT

    CERN Document Server

    Santos-Sanz, P; Barrera, L; Boehnhardt, H

    2008-01-01

    Photometric surveys of transNeptunian objects (TNOs) and Centaurs have suggested possible correlations between some orbital parameters and surface colors of classical objects, scattered disk objects (SDOs), and Centaurs. However, larger sample sizes are needed in order to corroborate or rule out the possible correlations and find some possible new ones. We use VLT-FORS images through BVRI filters of 32 Kuiper Belt Objects (KBOs) and obtain their colors after proper reduction and calibration. We study the possible correlations merging these new measurements with the VLT published results from the ESO large program and with the latest published results of the Meudon Multicolor Survey via non-parametric statistical tests. We obtain a large dataset of 116 objects (classical, SDOs and Centaurs) and, in addition to confirming most of the correlations and conclusions reached in the literature, some possible new correlations are found. The most interesting ones are some correlations of color vs. orbital parameters fo...

  18. The AVES adaptive optics spectrograph for the VLT: status report

    Science.gov (United States)

    Pallavicini, Roberto; Delabre, Bernard; Pasquini, Luca; Zerbi, Filippo M.; Bonanno, Giovanni; Comari, Maurizio; Conconi, Paolo; Mazzoleni, Ruben; Santin, Paolo; Damiani, Francesco; Di Marcantonio, Paolo; Franchini, Mariagrazia; Spano, Paolo; Bonifacio, P.; Catalano, Santo; Molaro, Paolo P.; Randich, S.; Rodono, Marcello

    2003-03-01

    We report on the status of AVES, the Adaptive-optics Visual Echelle Spectrograph proposed for the secondary port of the Nasmyth Adaptive Optics System (NAOS) recently installed at the VLT. AVES is an intermediate resolution (R ≍ 16,000) high-efficiency fixed- format echelle spectrograph which operates in the spectral band 500 - 1,000 nm. In addition to a high intrinsic efficiency, comparable to that of ESI at Keck II, it takes advantage of the adaptive optics correction provided by NAOS to reduce the sky and detector contribution in background-limited observations of weak sources, thus allowing a further magnitude gain with respect to comparable non-adaptive optics spectrographs. Simulations show that the instrument will be capable of reaching a magnitude V = 22.5 at S/N > 10 in two hours, two magnitudes weaker than GIRAFFE at the same resolution and 3 magnitudes weaker than the higher resolution UVES spectrograph. Imaging and coronographic functions have also been implemented in the design. We present the results of the final design study and we dicuss the technical and operational issues related to its implementation at the VLT as a visitor instrument. We also discuss the possibility of using a scaled-up non-adaptive optics version of the same design as an element of a double- or triple-arm intermediate-resolution spectrograph for the VLT. Such an option looks attractive in the context of a high-efficiency large-bandwidth (320 - 1,500 nm) spectrograph ("fast-shooter") being considered by ESO as a 2nd-generation VLT instrument.

  19. Selecting Your First Telescope.

    Science.gov (United States)

    Harrington, Sherwood

    1982-01-01

    Designed for first-time telescope purchasers, provides information on how a telescope works; major telescope types (refractors, reflectors, compound telescopes); tripod, pier, altazimuth, and equatorial mounts; selecting a telescope; visiting an astronomy club; applications/limitations of telescope use; and tips on buying a telescope. Includes a…

  20. Designing a common real-time controller for VLT applications

    Science.gov (United States)

    Bauvir, Bertrand; Wallander, Anders; Duhoux, Philippe; Huxley, Alexis; Karban, Robert

    2004-09-01

    The increasing number of digital control applications in the context of the VLT, and particularly the VLT Interferometer, brought the need to find a common solution to address the problems of performance and maintainability. Tools for Advanced Control (TAC) aims at helping both control and software engineers in the design and prototyping of real-time control applications by providing them with a set of standard functions and an easy way to combine them to create complex control algorithms. In this paper we describe the software architecture and design of TAC, the VLT standard for digital control applications. Algorithms are described at schematic level and take the form of a set of interconnected function blocks. Periodical execution of the algorithm as well as features like runtime modification of parameters and probing of internal data are also managed by TAC, allowing the application designers to avoid spending time writing low value software code and therefore focus on application-specific concerns. We also summarize the results achieved on the first actual applications using TAC, to manage real-time control or digital signal processing algorithms, currently deployed and being commissioned at Paranal Observatory.

  1. The ESO/VLT 3rd year Type Ia supernova data set from the Supernova Legacy Survey

    CERN Document Server

    Balland, C; Basa, S; Mouchet, M; Howell, D A; Astier, P; Carlberg, R G; Conley, A; Fouchez, D; Guy, J; Hardin, D; Hook, I M; Pain, R; Perrett, K; Pritchet, C J; Regnault, N; Rich, J; Sullivan, M; Antilogus, P; Arsenijevic, V; Du, J Le; Fabbro, S; Lidman, C; Mourao, A; Palanque-Delabrouille, Nathalie; Pécontal, E; Ruhlmann-Kleider, V

    2009-01-01

    We present 139 spectra of 124 Type Ia supernovae (SNeIa) that were observed at the ESO/VLT during the first three years of the Canada-France-Hawai Telescope (CFHT) Supernova Legacy Survey (SNLS). This homogeneous data set is used to test for redshift evolution of SNeIa spectra, and will be used in the SNLS 3rd year cosmological analyses. Spectra have been reduced and extracted with a dedicated pipeline that uses photometric information from deep CFHT Legacy Survey (CFHT-LS) reference images to trace, at sub-pixel accuracy, the position of the supernova on the spectrogram as a function of wavelength. It also separates the supernova and its host light in 60% of cases. The identification of the supernova candidates is performed using a spectrophotometric SNIa model. A total of 124 SNeIa, roughly 50% of the overall SNLS spectroscopic sample, have been identified using the ESO/VLT during the first three years of the survey. Their redshifts range from z=0.149 to z=1.031. The average redshift of the sample is z=0.63...

  2. Hubble and ESO's VLT provide unique 3D views of remote galaxies

    Science.gov (United States)

    2009-03-01

    Astronomers have obtained exceptional 3D views of distant galaxies, seen when the Universe was half its current age, by combining the twin strengths of the NASA/ESA Hubble Space Telescope's acute eye, and the capacity of ESO's Very Large Telescope to probe the motions of gas in tiny objects. By looking at this unique "history book" of our Universe, at an epoch when the Sun and the Earth did not yet exist, scientists hope to solve the puzzle of how galaxies formed in the remote past. ESO PR Photo 10a/09 A 3D view of remote galaxies ESO PR Photo 10b/09 Measuring motions in 3 distant galaxies ESO PR Video 10a/09 Galaxies in collision For decades, distant galaxies that emitted their light six billion years ago were no more than small specks of light on the sky. With the launch of the Hubble Space Telescope in the early 1990s, astronomers were able to scrutinise the structure of distant galaxies in some detail for the first time. Under the superb skies of Paranal, the VLT's FLAMES/GIRAFFE spectrograph (ESO 13/02) -- which obtains simultaneous spectra from small areas of extended objects -- can now also resolve the motions of the gas in these distant galaxies (ESO 10/06). "This unique combination of Hubble and the VLT allows us to model distant galaxies almost as nicely as we can close ones," says François Hammer, who led the team. "In effect, FLAMES/GIRAFFE now allows us to measure the velocity of the gas at various locations in these objects. This means that we can see how the gas is moving, which provides us with a three-dimensional view of galaxies halfway across the Universe." The team has undertaken the Herculean task of reconstituting the history of about one hundred remote galaxies that have been observed with both Hubble and GIRAFFE on the VLT. The first results are coming in and have already provided useful insights for three galaxies. In one galaxy, GIRAFFE revealed a region full of ionised gas, that is, hot gas composed of atoms that have been stripped of

  3. Time variability of Neptune’s horizontal and vertical cloud structure revealed by VLT/SINFONI and Gemini/NIFS from 2009 to 2013

    Science.gov (United States)

    Irwin, Patrick G.; Fletcher, Leigh N.; Orton, Glenn S.; Teanby, Nicholas A.; Davis, Gary R.; Tice, Dane; Hurley, Jane; Owen, Stephanie J.

    2014-11-01

    New observations of Neptune’s clouds in the near infrared were acquired in October 2013 with SINFONI on ESO’s Very Large Telescope (VLT) in Chile. SINFONI is an Integral Field Unit spectrometer returning a 64x64 pixel image with 2048 wavelengths. Image cubes in the J-band (1.1 - 1.41 micron) and H-band (1.43 - 1.87 micron) were obtained at spatial resolutions of 0.1” and 0.025” per pixel, while SINFONI’s adaptive optics provided an effective resolution of approximately 0.1”. Image cubes were obtained at the start and end of three successive nights to monitor the temporal development of discrete clouds both at short timescales (i.e. during a single night) as well as over the longer period of the three-day observing run. These observations were compared with similar H-band observations obtained in September 2009 with the NIFS Integral Field Unit spectrometer on the Gemini-North telescope in Hawaii and previously reported by Irwin et al., Icarus 216, 141-158, 2011. We find both similarities and differences between these observations, spaced by four years. The same overall cloud structure is seen with high, bright clouds visible at mid-latitudes (20-40°N, S); with slightly lower transient clouds at the equator; together with small discrete clouds seen circling the pole at a latitude of approximately 60°S. However, while discrete clouds were visible at this latitude at both the main cloud deck level (at 2-3 bars) and in the upper troposphere (100-500mb) in 2009, no clear deep, discrete circumpolar clouds were visible in 2013. The nature of these deep circumpolar discrete clouds is intriguing. While it is possible that in 2013 these deeper clouds were masked by faster moving, overlying features, we consider that it is unlikely that this should have happened in 2013, but not in 2009 when the upper cloud activity was generally similar. Hence, these observations may have detected a real temporal variation in the occurrence of Neptune’s deep clouds, pointing

  4. Southern Fireworks above ESO Telescopes

    Science.gov (United States)

    1999-05-01

    New Insights from Observations of Mysterious Gamma-Ray Burst International teams of astronomers are now busy working on new and exciting data obtained during the last week with telescopes at the European Southern Observatory (ESO). Their object of study is the remnant of a mysterious cosmic explosion far out in space, first detected as a gigantic outburst of gamma rays on May 10. Gamma-Ray Bursters (GRBs) are brief flashes of very energetic radiation - they represent by far the most powerful type of explosion known in the Universe and their afterglow in optical light can be 10 million times brighter than the brightest supernovae [1]. The May 10 event ranks among the brightest one hundred of the over 2500 GRB's detected in the last decade. The new observations include detailed images and spectra from the VLT 8.2-m ANTU (UT1) telescope at Paranal, obtained at short notice during a special Target of Opportunity programme. This happened just over one month after that powerful telescope entered into regular service and demonstrates its great potential for exciting science. In particular, in an observational first, the VLT measured linear polarization of the light from the optical counterpart, indicating for the first time that synchrotron radiation is involved . It also determined a staggering distance of more than 7,000 million light-years to this GRB . The astronomers are optimistic that the extensive observations will help them to better understand the true nature of such a dramatic event and thus to bring them nearer to the solution of one of the greatest riddles of modern astrophysics. A prime example of international collaboration The present story is about important new results at the front-line of current research. At the same time, it is also a fine illustration of a successful collaboration among several international teams of astronomers and the very effective way modern science functions. It began on May 10, at 08:49 hrs Universal Time (UT), when the Burst

  5. VISTA: Pioneering New Survey Telescope Starts Work

    Science.gov (United States)

    2009-12-01

    A new telescope - VISTA (the Visible and Infrared Survey Telescope for Astronomy) - has just started work at ESO's Paranal Observatory and has made its first release of pictures. VISTA is a survey telescope working at infrared wavelengths and is the world's largest telescope dedicated to mapping the sky. Its large mirror, wide field of view and very sensitive detectors will reveal a completely new view of the southern sky. Spectacular new images of the Flame Nebula, the centre of our Milky Way galaxy and the Fornax Galaxy Cluster show that it is working extremely well. VISTA is the latest telescope to be added to ESO's Paranal Observatory in the Atacama Desert of northern Chile. It is housed on the peak adjacent to the one hosting the ESO Very Large Telescope (VLT) and shares the same exceptional observing conditions. VISTA's main mirror is 4.1 metres across and is the most highly curved mirror of this size and quality ever made - its deviations from a perfect surface are less than a few thousandths of the thickness of a human hair - and its construction and polishing presented formidable challenges. VISTA was conceived and developed by a consortium of 18 universities in the United Kingdom [1] led by Queen Mary, University of London and became an in-kind contribution to ESO as part of the UK's accession agreement. The telescope design and construction were project-managed by the Science and Technology Facilities Council's UK Astronomy Technology Centre (STFC, UK ATC). Provisional acceptance of VISTA was formally granted by ESO at a ceremony at ESO's Headquarters in Garching, Germany, attended by representatives of Queen Mary, University of London and STFC, on 10 December 2009 and the telescope will now be operated by ESO. "VISTA is a unique addition to ESO's observatory on Cerro Paranal. It will play a pioneering role in surveying the southern sky at infrared wavelengths and will find many interesting targets for further study by the Very Large Telescope, ALMA and

  6. Particle Accelerators in the Hot Spots of the Radio Galaxy 3C445 Imaged With the VLT

    CERN Document Server

    Prieto, M A; Mack, K H; Brunetti, Gianfranco; Mack, Karl-Heinz

    2002-01-01

    Hot spots (HSs) are regions of enhanced radio emission produced by supersonic jets at the tip of the radio lobes of powerful radiosources. Obtained with the Very Large Telescope (VLT), images of the HSs in the radio galaxy 3C445 show bright knots embedded in diffuse optical emission distributed along the post shock region created by the impact of the jet into the intergalactic medium. The observations reported here confirm that relativistic electrons are accelerated by Fermi-I acceleration processes in HSs. Furthermore, both the diffuse emission tracing the rims of the front shock and the multiple knots demonstrate the presence of additional continuous re-acceleration processes of electrons (Fermi-II).

  7. Performance of the VLT Planet Finder SPHERE I. Photometry and astrometry precision with IRDIS and IFS in laboratory

    CERN Document Server

    Zurlo, A; Mesa, D; Gratton, R; Moutou, C; Langlois, M; Claudi, R U; Pueyo, L; Boccaletti, A; Baruffolo, A; Beuzit, J -L; Costille, A; Desidera, S; Dohlen, K; Feldt, M; Fusco, T; Henning, T; Kasper, M; Martinez, P; Moeller-Nilsson, O; Mouillet, D; Pavlov, A; Puget, P; Sauvage, J -F; Turatto, M; Udry, S; Vakili, F; Waters, R; Wildi, R F

    2014-01-01

    The new planet finder for the Very Large Telescope (VLT), the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), just had its first light in Paranal. A dedicated instrument for the direct detection of planets, SPHERE, is composed of a polametric camera in visible light, the Zurich IMager POLarimeter (ZIMPOL), and two near-infrared sub-systems: the Infra-Red Dual-beam Imager and Spectrograph (IRDIS), a multi-purpose camera for imaging, polarimetry, and long-slit spectroscopy, and the integral field spectrograph (IFS), an integral field spectrograph. We present the results obtained from the analysis of data taken during the laboratory integration and validation phase, after the injection of synthetic planets. Since no continuous field rotation could be performed in the laboratory, this analysis presents results obtained using reduction techniques that do not use the angular differential imaging (ADI) technique. To perform the simulations, we used the instrumental point spread function (PSF) and mod...

  8. On-sky results of the adaptive optics MACAO for the new IR-spectrograph CRIRES at VLT

    CERN Document Server

    Paufique, J; Delabre, B; Donaldson, R; Esteves, R; Fedrigo, E; Gigan, P; Gojak, D; Hubin, N; Kasper, M; Kaeufl, U; Lizon, J L; Marchetti, E; Oberti, S; Pirard, J F; Pozna, E; Santos, J; Stroebele, S; Tordo, S; Lizon, JL.; Pirard, JF.

    2006-01-01

    The adaptive optics MACAO has been implemented in 6 focii of the VLT observatory, in three different flavors. We present in this paper the results obtained during the commissioning of the last of these units, MACAO-CRIRES. CRIRES is a high-resolution spectrograph, which efficiency will be improved by a factor two at least for point-sources observations with a NGS brighter than R=15. During the commissioning, Strehl exceeding 60% have been observed with fair seeing conditions, and a general description of the performance of this curvature adaptive optics system is done.

  9. Status and new operation modes of the versatile VLT/NaCo

    Science.gov (United States)

    Girard, Julien H. V.; Kasper, Markus; Quanz, Sascha P.; Kenworthy, Matthew A.; Rengaswamy, Sridharan; Schödel, Rainer; Gallenne, Alexandre; Gillessen, Stefan; Huerta, Nicolas; Kervella, Pierre; Kornweibel, Nick; Lenzen, Rainer; Mérand, Antoine; Montagnier, Guillaume; O'Neal, Jared; Zins, Gérard

    2010-07-01

    This paper aims at giving an update on the most versatile Adaptive Optics fed instrument to date, the well known and successful NACO*. Although NACO is only scheduled for about two more years† at the Very Large Telescope (VLT), it keeps on evolving with additional operation modes bringing original astronomical results. The high contrast imaging community uses it creatively as a test-bench for SPHERE‡ and other second generation planet imagers. A new visible wavefront sensor (WFS) optimized for Laser Guide Star (LGS) operations has been installed and tested, the cube mode is more and more required for frame selection on bright sources, a seeing enhancer mode (no tip/tilt correction) is now offered to provide full sky coverage and welcome all kind of extragalactic applications, etc. The Instrument Operations Team (IOT) and Paranal engineers are currently working hard at maintaining the instrument overall performances but also at improving them and offering new capabilities, providing the community with a well tuned and original instrument for the remaining time it is being used. The present contribution delivers a non-exhaustive overview of the new modes and experiments that have been carried out in the past months.

  10. VLT Suzaku observations of the Fermi pulsar PSR J1028-5819

    CERN Document Server

    Mignani, R P; Esposito, P; De Luca, A; Marelli, M; Oates, S R; Saz-Parkinson, P

    2012-01-01

    We used optical images taken with the Very Large Telescope (VLT) in the B and V bands to search for the optical counterpart of PSR J1028-5819 or constrain its optical brightness. At the same time, we used an archival Suzaku observation to confirm the preliminary identification of the pulsar's X-ray counterpart obtained by Swift. Due to the large uncertainty on the pulsar's radio position and the presence of a bright (V = 13.2) early F-type star at < 4", we could not detect its counterpart down to flux limits of B~25.4 and V ~25.3, the deepest obtained so far for PSR J1028-5819. From the Suzaku observations, we found that the X-ray spectrum of the pulsar's candidate counterpart is best-fit by a power-law with spectral index 1.7 +/- 0.2 and an absorption column density NH < 10^21 cm-2, which would support the proposed X-ray identification. Moreover, we found possible evidence for the presence of diffuse emission around the pulsar. If real, and associated with a pulsar wind nebula (PWN), its surface bright...

  11. Upper limits for mass and radius of objects around Proxima Cen from SPHERE/VLT

    Science.gov (United States)

    Mesa, D.; Zurlo, A.; Milli, J.; Gratton, R.; Desidera, S.; Langlois, M.; Vigan, A.; Bonavita, M.; Antichi, J.; Avenhaus, H.; Baruffolo, A.; Biller, B.; Boccaletti, A.; Bruno, P.; Cascone, E.; Chauvin, G.; Claudi, R. U.; De Caprio, V.; Fantinel, D.; Farisato, G.; Girard, J.; Giro, E.; Hagelberg, J.; Incorvaia, S.; Janson, M.; Kral, Q.; Lagadec, E.; Lagrange, A.-M.; Lessio, L.; Meyer, M.; Peretti, S.; Perrot, C.; Salasnich, B.; Schlieder, J.; Schmid, H.-M.; Scuderi, S.; Sissa, E.; Thalmann, C.; Turatto, M.

    2017-03-01

    The recent discovery of an earth-like planet around Proxima Centauri has drawn much attention to this star and its environment. We performed a series of observations of Proxima Centauri using Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), the planet-finder instrument installed at the European Southern Observatory (ESO) Very Large Telescope (VLT) UT3, using its near-infrared modules, InfraRed Dual-band Imager and Spectrograph (IRDIS) and IFS. No planet was detected directly, but we set upper limits on the mass up to 7 au by exploiting the AMES-COND models. Our IFS observations reveal that no planet more massive than ∼6-7 MJup can be present within 1 au. The dual-band imaging camera IRDIS also enables us to probe larger separations than other techniques such as radial velocity or astrometry. We obtained mass limits of the order of 4 MJup at separations of 2 au or larger, representing the most stringent mass limits at separations larger than 5 au available at the moment. We also made an attempt to estimate the radius of possible planets around Proxima using the reflected light. Since the residual noise for the observations is dominated by photon noise and thermal background, longer exposures in good observing conditions could improve the achievable contrast limit further.

  12. CLASH-VLT: Testing the Nature of Gravity with Galaxy Cluster Mass Profiles

    CERN Document Server

    Pizzuti, L; Borgani, S; Amendola, L; Umetsu, K; Biviano, A; Girardi, M; Rosati, P; Balestra, I; Caminha, G B; Frye, B; Koekemoer, A; Grillo, C; Lombardi, M; Mercurio, A; Nonino, M

    2016-01-01

    We use high-precision kinematic and lensing measurements of the total mass profile of the dynamically relaxed galaxy cluster MACS J1206.2-0847 at $z=0.44$ to estimate the value of the ratio $\\eta=\\Psi/\\Phi$ between the two scalar potentials in the linear perturbed Friedmann-Lemaitre-Robertson-Walker metric.[...] Complementary kinematic and lensing mass profiles were derived from exhaustive analyses using the data from the Cluster Lensing And Supernova survey with Hubble (CLASH) and the spectroscopic follow-up with the Very Large Telescope (CLASH-VLT). Whereas the kinematic mass profile tracks only the time-time part of the perturbed metric (i.e. only $\\Phi$), the lensing mass profile reflects the contribution of both time-time and space-space components (i.e. the sum $\\Phi+\\Psi$). We thus express $\\eta$ as a function of the mass profiles and perform our analysis over the radial range $0.5\\,Mpc\\le r\\le r_{200}=1.96\\,Mpc$. Using a spherical Navarro-Frenk-White mass profile, which well fits the data, we obtain $...

  13. The VLT-FLAMES Tarantula Survey II: R139 revealed as a massive binary system

    CERN Document Server

    Taylor, W D; Sana, H; Walborn, N R; de Mink, S E; Stroud, V E; Alvarez-Candal, A; Barbá, R H; Bestenlehner, J M; Bonanos, A Z; Brott, I; Crowther, P A; de Koter, A; Friedrich, K; Gräfener, G; Hénault-Brunet, V; Herrero, A; Kaper, L; Langer, N; Lennon, D J; Apellániz, J Maíz; Markova, N; Morrell, N; Monaco, L; Vink, J S

    2011-01-01

    We report the discovery that R139 in 30 Doradus is a massive spectroscopic binary system. Multi-epoch optical spectroscopy of R139 was obtained as part of the VLT-FLAMES Tarantula Survey, revealing a double-lined system. The two components are of similar spectral types; the primary exhibits strong C III 4650 emission and is classified as an O6.5 Iafc supergiant, while the secondary is an O6 Iaf supergiant. The radial-velocity variations indicate a highly eccentric orbit with a period of 153.9 days. Photometry obtained with the Faulkes Telescope South shows no evidence for significant variability within an 18 month period. The orbital solution yields lower mass limits for the components of M1sin^3 i = 78 \\pm 8 Msun and M2sin^3 i = 66 \\pm 7 Msun. As R139 appears to be the most massive binary system known to contain two evolved Of supergiants, it will provide an excellent test for atmospheric and evolutionary models.

  14. VLT/X-Shooter spectroscopy of the afterglow of the Swift GRB 130606A. Chemical abundances and reionisation at z ~ 6

    Science.gov (United States)

    Hartoog, O. E.; Malesani, D.; Fynbo, J. P. U.; Goto, T.; Krühler, T.; Vreeswijk, P. M.; De Cia, A.; Xu, D.; Møller, P.; Covino, S.; D'Elia, V.; Flores, H.; Goldoni, P.; Hjorth, J.; Jakobsson, P.; Krogager, J.-K.; Kaper, L.; Ledoux, C.; Levan, A. J.; Milvang-Jensen, B.; Sollerman, J.; Sparre, M.; Tagliaferri, G.; Tanvir, N. R.; de Ugarte Postigo, A.; Vergani, S. D.; Wiersema, K.; Datson, J.; Salinas, R.; Mikkelsen, K.; Aghanim, N.

    2015-08-01

    Context. The reionisation of the Universe is a process that is thought to have ended around z ~ 6, as inferred from spectroscopy of distant bright background sources, such as quasars (QSO) and gamma-ray burst (GRB) afterglows. Furthermore, spectroscopy of a GRB afterglow provides insight in its host galaxy, which is often too dim and distant to study otherwise. Aims: For the Swift GRB 130606A at z = 5.913 we have obtained a high S/N spectrum covering the full optical and near-IR wavelength region at intermediate spectral resolution with VLT/X-Shooter. We aim to measure the degree of ionisation of the intergalactic medium (IGM) between z = 5.02-5.84 and to study the chemical abundance pattern and dust content of its host galaxy. Methods: We estimated the UV continuum of the GRB afterglow using a power-law extrapolation, then measured the flux decrement due to absorption at Lyα,β, and γ wavelength regions. Furthermore, we fitted the shape of the red damping wing of Lyα. The hydrogen and metal absorption lines formed in the host galaxy were fitted with Voigt profiles to obtain column densities. We investigated whether ionisation corrections needed to be applied. Results: Our measurements of the Lyα-forest optical depth are consistent with previous measurements of QSOs, but have a much smaller uncertainty. The analysis of the red damping wing yields a neutral fraction xH i 5.6. GRBs are useful probes of the ionisation state of the IGM in the early Universe, but because of internal scatter we need a larger statistical sample to draw robust conclusions. The high [Si/Fe] in the host can be due to dust depletion, α-element enhancement, or a combination of both. The very high value of [ Al/Fe ] = 2.40 ± 0.78 might be due to a proton capture process and is probably connected to the stellar population history. We estimate the host metallicity to be -1.7 Telescope (VLT), Unit 2 - Kueyen, operated by the European Southern Observatory (ESO) on Cerro Paranal, Chile. Partly

  15. Operational metrics for the ESO Very Large Telescope: lessons learned and future steps

    Science.gov (United States)

    Primas, F.; Marteau, S.; Tacconi-Garman, L. E.; Mainieri, V.; Mysore, S.; Rejkuba, M.; Hilker, M.; Patat, F.; Sterzik, M.; Kaufer, A.; Mieske, S.

    2016-07-01

    When ESO's Very Large Telescope opened its first dome in April 1999 it was the first ground-based facility to offer to the scientific community access to an 8-10m class telescope with both classical and queue observing. The latter was considered to be the most promising way to ensure the observing flexibility necessary to execute the most demanding scientific programmes under the required, usually very well defined, conditions. Since then new instruments have become operational and 1st generation ones replaced, filling the 12 VLT foci and feeding the VLT Interferometer and its four Auxiliary Telescopes. Operating efficiently such a broad range of instruments installed and available every night of the year on four 8-metre telescopes offers many challenges. Although it may appear that little has changed since 1999, the underlying VLT operational model has evolved in order to accommodate different requirements from the user community and features of new instruments. Did it fulfil its original goal and, if so, how well? How did it evolve? What are the lessons learned after more than 15 years of operations? A careful analysis and monitoring of statistics and trends in Phase 1 and Phase 2 has been deployed under the DOME (Dashboard for Operational Metrics at ESO) project. The main goal of DOME is to provide robust metrics that can be followed with time in a user-friendly manner. Here, we summarize the main findings on the handling of service mode observations and present the most recent developments.

  16. VLT instrumentation control: the collaboration of OATs with ESO

    Science.gov (United States)

    Santin, P.

    The collaboration of the Astrophysics Technology Group (ATG) of the Astronomical Observatory of Trieste with ESO will be presented. It may be considered as an example of a good practice in the collaboration of a peripheral Institute with ESO. Started in 1985, it spans almost all the time since Italy joined ESO in 1982. The Trieste Astrophysics Technology Group (ATG) participated in many technological enterprise of ESO, from Remote Observing to VLT instrumentation and to ALMA ACS, and is now looking for the challenging E-ELT.

  17. VLT spectroscopy of massive stars in NGC55

    Directory of Open Access Journals (Sweden)

    N. Castro

    2007-01-01

    Full Text Available We present the first spectroscopy study of massive stars in NGC55. The data, taken with VLT-FORS2 allow us to provide spectral classification for 200 objects located through- out the galaxy. From this sample, suitable B-type supergiants are chosen for subsequent higher resolution spectroscopic observations that will enable a quantitative study. The stellar abundances will be a key point in the study of galaxy chemical evolution. We also discuss how GTC-OSIRIS can be a valuable tool for similar studies.

  18. Robotic Telescopes

    Science.gov (United States)

    Akerlof, C. W.

    2001-05-01

    Since the discovery of gamma-ray bursts, a number of groups have attempted to detect correlated optical transients from these elusive objects. Following the flight of the BATSE instrument on the Compton Gamma-Ray Observatory in 1991, a prompt burst coordinate alert service, BACODINE (now GCN) became available to ground-based telescopes. Several instruments were built to take advantage of this facility, culminating in the discovery of a bright optical flash associated with GRB990123. To date, that single observation remains unique - no other prompt flashes have been seen for a dozen or so other bursts observed with comparably short response times. Thus, GRB prompt optical luminosities may be considerably dimmer than observed for the GRB990123 event or even absent altogether. A new generation of instruments is prepared to explore these possibilties using burst coordinates provided by HETE-2, Swift, Ballerina, Agile and other satellite missions. These telescopes have response times as short as a few seconds and reach limiting magnitudes, m_v 20, guaranteeing a sensitivity sufficient to detect the afterglow many hours later. Results from these experiments should provide important new data about the dynamics and locale of GRBs.

  19. RADIAL VELOCITIES FROM VLT-KMOS SPECTRA OF GIANT STARS IN THE GLOBULAR CLUSTER NGC 6388

    Energy Technology Data Exchange (ETDEWEB)

    Lapenna, E.; Mucciarelli, A.; Lanzoni, B.; Ferraro, F. R.; Dalessandro, E. [Dipartimento di Fisica e Astronomia, Università degli Studi di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Origlia, L. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani, 1, I-40127 Bologna (Italy); Valenti, E. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München (Germany); Cirasuolo, M. [Institute for Astronomy, University of Edinburgh and STFC, UK Astronomy Technology Center Royal Observatory, Blackford Hill, EH9 3HJ, Edinburgh (United Kingdom)

    2015-01-01

    We present new radial velocity measurements for 82 stars, members of the Galactic globular cluster (GC) NGC 6388, obtained from ESO-VLT K-band Multi Object Spectrograph (KMOS) spectra acquired during the instrument Science Verification. The accuracy of the wavelength calibration is discussed and a number of tests of the KMOS response are presented. The cluster systemic velocity obtained (81.3 ± 1.5 km s{sup –1}) is in very good agreement with previous determinations. While a hint of ordered rotation is found between 9'' and 20'' from the cluster center, where the distribution of radial velocities is clearly bimodal, more data are needed before drawing any firm conclusions. The acquired sample of radial velocities has also been used to determine the cluster velocity dispersion (VD) profile between ∼9'' and 70'', supplementing previous measurements at r < 2'' and r > 60'' obtained with ESO-SINFONI and ESO-FLAMES spectroscopy, respectively. The new portion of the VD profile nicely matches the previous ones, better defining the knee of the distribution. The present work clearly shows the effectiveness of a deployable integral field unit in measuring the radial velocities of individual stars for determining the VD profile of Galactic GCs. It represents the pilot project for an ongoing large program with KMOS and FLAMES at the ESO-VLT, aimed at determining the next generation of VD and rotation profiles for a representative sample of GCs.

  20. A valiant little terminal: A VLT user's manual

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, A.

    1990-12-01

    This report is a manual for the valiant little terminal. Information covered in this report is as follow: an introduction to VLT; installation; starting up; text screen menus; graphics screen menus; introduction to VLT's scripting facility; quick reference section; and troubleshooting.

  1. Intracluster light properties in the CLASH-VLT cluster MACS J1206.2-0847

    Science.gov (United States)

    Presotto, V.; Girardi, M.; Nonino, M.; Mercurio, A.; Grillo, C.; Rosati, P.; Biviano, A.; Annunziatella, M.; Balestra, I.; Cui, W.; Sartoris, B.; Lemze, D.; Ascaso, B.; Moustakas, J.; Ford, H.; Fritz, A.; Czoske, O.; Ettori, S.; Kuchner, U.; Lombardi, M.; Maier, C.; Medezinski, E.; Molino, A.; Scodeggio, M.; Strazzullo, V.; Tozzi, P.; Ziegler, B.; Bartelmann, M.; Benitez, N.; Bradley, L.; Brescia, M.; Broadhurst, T.; Coe, D.; Donahue, M.; Gobat, R.; Graves, G.; Kelson, D.; Koekemoer, A.; Melchior, P.; Meneghetti, M.; Merten, J.; Moustakas, L. A.; Munari, E.; Postman, M.; Regős, E.; Seitz, S.; Umetsu, K.; Zheng, W.; Zitrin, A.

    2014-05-01

    Aims: We aim constrain the assembly history of clusters by studying the intracluster light (ICL) properties, estimating its contribution to the fraction of baryons in stars, f∗, and understanding possible systematics or bias using different ICL detection techniques. Methods: We developed an automated method, GALtoICL, based on the software GALAPAGOS, to obtain a refined version of typical BCG+ICL maps. We applied this method to our test case MACS J1206.2-0847, a massive cluster located at z ~ 0.44, which is part of the CLASH sample. Using deep multiband Subaru images, we extracted the surface brightness (SB) profile of the BCG+ICL and studied the ICL morphology, color, and contribution to f∗ out to R500. We repeated the same analysis using a different definition of the ICL, SBlimit method, i.e., a SB cut-off level, to compare the results. Results: The most peculiar feature of the ICL in MACS1206 is its asymmetric radial distribution, with an excess in the SE direction and extending toward the second brightest cluster galaxy, which is a post starburst galaxy. This suggests an interaction between the BCG and this galaxy that dates back to τ ≤ 1.5 Gyr. The BCG+ICL stellar content is ~8% of M∗,500, and the (de-) projected baryon fraction in stars is f∗ = 0.0177(0.0116), in excellent agreement with recent results. The SBlimit method provides systematically higher ICL fractions and this effect is stronger at lower SB limits. This is due to the light from the outer envelopes of member galaxies that contaminate the ICL. Though more time consuming, the GALtoICL method provides safer ICL detections that are almost free of this contamination. This is one of the few ICL study at redshift z > 0.3. At completion, the CLASH/VLT program will allow us to extend this analysis to a statistically significant cluster sample spanning a wide redshift range: 0.2 ≲ z ≲ 0.6. Based on data collected at the NASJ Subaru telescope, at the ESO VLT (prog.ID 186.A-0798), and the

  2. HST WFC3 Observations of Uranus' 2014 Storm Clouds and Comparison with VLT/SINFONI and IRTF/Spex Observations

    Science.gov (United States)

    Irwin, Patrick G. J.; Wong, Michael H.; Simon, Amy A.; Orton, G. S.; Toledo, Daniel

    2017-01-01

    In November 2014 Uranus was observed with the Wide Field Camera 3 (WFC3) instrument of the Hubble Space Telescope as part of the Hubble 2020: Outer Planet Atmospheres Legacy program, OPAL. OPAL annually maps Jupiter, Uranus and Neptune (and will also map Saturn from 2018) in several visible near- infrared wavelength filters. The Uranus 2014 OPAL observations were made on the 89th November at a time when a huge cloud complex, first observed by de Pater et al. (2015) and subsequently tracked by professional and amateur astronomers (Sayanagi et al., 2016), was present at 30-40deg N. We imaged the entire visible atmosphere, including the storm system, in seven filters spanning 467924 nm, capturing variations in the coloration of Uranus clouds and also vertical distribution due to wavelength dependent changes in Rayleigh scattering and methane absorption optical depth. Here we analyse these new HST observations with the NEMESIS radiative-transfer and retrieval code in multiple-scattering mode to determine the vertical cloud structure in and around the storm cloud system. The same storm system was also observed in the H-band (1.4-1.8 micrometers) with the SINFONI Integral Field Unit Spectrometer on the Very Large Telescope (VLT) on 31st October and 11th November, reported by Irwin et al. (2016, 10.1016j.icarus.2015.09.010). To constrain better the cloud particle sizes and scattering properties over a wide wavelength range we also conducted a limb-darkening analysis of the background cloud structure in the 30-40deg N latitude band by simultaneously fitting: a) these HSTOPAL observations at a range of zenith angles; b) the VLTSINFONI observations at a range of zenith angles; and c) IRTFSpeX observations of this latitude band made in 2009 at a single zenith angle of 23deg, spanning the wavelength range 0.8-1.8 micrometers (Irwin et al., 2015, 10.1016j.icarus.2014.12.020). We find that the HST observations, and the combined HSTVLTIRTF observations at all locations are well

  3. Holographic telescope

    Science.gov (United States)

    Odhner, Jefferson E.

    2016-07-01

    Holographic optical elements (HOEs) work on the principal of diffraction and can in some cases replace conventional optical elements that work on the principal of refraction. An HOE can be thinner, lighter, can have more functionality, and can be lower cost than conventional optics. An HOE can serve as a beam splitter, spectral filter, mirror, and lens all at the same time. For a single wavelength system, an HOE can be an ideal solution but they have not been widely accepted for multispectral systems because they suffer from severe chromatic aberration. A refractive optical system also suffers from chromatic aberration but it is generally not as severe. To color correct a conventional refractive optical system, a flint glass and a crown glass are placed together such that the color dispersion of the flint and the crown cancel each other out making an achromatic lens (achromat) and the wavelengths all focus to the same point. The color dispersion of refractive lenses and holographic lenses are opposite from each other. In a diffractive optical system, long wavelengths focus closer (remember for HOEs: RBM "red bends more") than nominal focus while shorter wavelengths focus further out. In a refractive optical system, it is just the opposite. For this reason, diffractives can be incorporated into a refractive system to do the color correction and often cut down on the number of optical elements used [1.]. Color correction can also be achieved with an all-diffractive system by combining a holographic optical element with its conjugate. In this way the color dispersion of the first holographic optical element can be cancelled by the color dispersion of the second holographic optic. It is this technique that will be exploited in this paper to design a telescope made entirely of holographic optical elements. This telescope could be more portable (for field operations) the same technique could be used to make optics light enough for incorporation into a UAV.

  4. Specsim: A Software Simulator for Integral Field Unit Spectrometers

    Science.gov (United States)

    Lorente, N. P. F.; Glasse, A. C. H.; Wright, G. S.; Ramsay, S. K.; Evans, C. J.

    As the scale and complexity of each generation of telescopes and their instruments increases, the requirement for a means of furthering our understanding of their properties and limitations, from the initial design to the point of commissioning also grows. An effective way of learning about the behaviour of a new system is to employ a software simulator to generate synthetic astronomical data, based on a given set of telescope and instrument characteristics. The Specsim tool has been developed to model, in software, the operation of Integral Field Unit (IFU) spectrometers, so as to give the science, engineering and operations teams responsible for designing, building and running such instruments a preview of the data products before the system is operational. Specsim generates synthetic data frames approximating those which will be taken by the instrument. The program models astronomical sources and generates detector frames using the predicted and measured properties of the telescope and instrument. These frames can then be used to illustrate and inform a range of activities, including refining the design, developing calibration strategies and the development and testing of data reduction pipelines. Specsim is currently used to model the Medium Resolution Spectrograph on JWST-MIRI, and KMOS on the ESO VLT. The software has been designed in a modular fashion, thus allowing the tool to expand easily to model future instruments, by incorporating new models into the existing infrastructure.

  5. Ground-based astrometry with wide field imagers. V. Application to near-infrared detectors: HAWK-I@VLT/ESO

    CERN Document Server

    Libralato, M; Bedin, L R; Piotto, G; Platais, I; Kissler-Patig, M; Milone, A P; .,

    2014-01-01

    High-precision astrometry requires accurate point-spread function modeling and accurate geometric-distortion corrections. This paper demonstrates that it is possible to achieve both requirements with data collected at the high acuity wide-field K-band imager (HAWK-I), a wide-field imager installed at the Nasmyth focus of UT4/VLT ESO 8m telescope. Our final astrometric precision reaches ~3 mas per coordinate for a well-exposed star in a single image with a systematic error less than 0.1 mas. We constructed calibrated astro-photometric catalogs and atlases of seven fields: the Baade's Window, NGC 6656, NGC 6121, NGC 6822, NGC 6388, NGC 104, and the James Webb Space Telescope calibration field in the Large Magellanic Cloud. We make these catalogs and images electronically available to the community. Furthermore, as a demonstration of the efficacy of our approach, we combined archival material taken with the optical wide-field imager at the MPI/ESO 2.2m with HAWK-I observations. We showed that we are able to achi...

  6. NESTOR Neutrino Telescope Status Report

    Science.gov (United States)

    Grieder, P. K. F.; NESTOR Collaboration; Aloupis, A.; Anassontzis, E. G.; Arvanitis, N.; Babalis, A.; Ball, A.; Bourlis, G.; Butkevich, A. V.; Chinowsky, W.; Christopoulos, P. E.; Darsaklis, A.; Dedenko, L. G.; Elistrup, D.; Fahrun, E.; Gialis, J.; Goudis, Ch.; Grammatikakis, G.; Green, C.; Karaevsky, S. K.; Katrivanos, P.; Keussen, U.; Kiskiras, J.; Knutz, Th.; Kolostelov, D.; Komlev, K.; Kontaxis, J.; Koske, P.; Learned, J. G.; Ledenev, V. V.; Leisos, A.; Limberopoulos, G.; Ludvig, J.; Makris, J.; Manousakis-Katsikakis, A.; Markopoulos, E.; Matsuno, S.; Mielke, J.; Mihos, Th.; Minkowski, P.; Mironovich, A. A.; Mitiguy, R.; Nounos, S.; Nygren, D. R.; Papageorgiou, K.; Passera, M.; Politis, C.; Preve, P.; Przybylski, G. T.; Rathlev, J.; Resvanis, L. K.; Rosen, M.; Schmidt, N.; Schmidt, Th.; Siotis, I.; Sopher, J.; Staveris, T.; Stavrakakis, G.; Stokstad, R.; Surin, N. M.; Tsagli, V.; Tsirigotis, A.; Tsirmpas, J.; Tzamarias, S.; Vasiliev, O.; Vaskine, O.; Voigt, W.; Vougioukas, A.; Voulgaris, G.; Zacharov, L. M.; Zheleznykh, I. M.; Zhukov, A.

    2003-07-01

    The first so-called flo or with 12 detector modules of the NESTOR deep sea high energy muon and neutrino telescope had been deployed successfully this March (2003) together with its electronics system. Since that data the system and the associated environmental monitoring units are operating properly and data

  7. Design of a Full-Stokes Polarimeter for VLT/X-shooter

    CERN Document Server

    Snik, Frans; Navarro, Ramon; Groot, Paul; Kaper, Lex; de Wijn, Alfred

    2012-01-01

    X-shooter is one of the most popular instruments at the VLT, offering instantaneous spectroscopy from 300 to 2500 nm. We present the design of a single polarimetric unit at the polarization-free Cassegrain focus that serves all three spectrograph arms of X-shooter. It consists of a calcite Savart plate as a polarizing beam-splitter and a rotatable crystal retarder stack as a "polychromatic modulator". Since even "superachromatic" wave plates have a wavelength range that is too limited for X-shooter, this novel modulator is designed to offer close-to-optimal polarimetric efficiencies for all Stokes parameters at all wavelengths. We analyze the modulator design in terms of its polarimetric performance, its temperature sensitivity, and its polarized fringes. Furthermore, we present the optical design of the polarimetric unit. The X-shooter polarimeter will furnish a myriad of science cases: from measuring stellar magnetic fields (e.g., Ap stars, white dwarfs, massive stars) to determining asymmetric structures a...

  8. X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope

    CERN Document Server

    Vernet, Joel; D'Odorico, S; Kaper, L; Kjaergaard, P; Hammer, F; Randich, S; Zerbi, F; Groot, P M; Hjorth, J; Guinouard, I; Navarro, R; Adolfse, T; Albers, P W; Amans, J -P; Andersen, J J; Andersen, M I; Binetruy, P; Bristow, P; Castillo, R; Chemla, F; Christensen, L; Conconi, P; Conzelmann, R; Dam, J; De Caprio, V; Postigo, A De Ugarte; Delabre, B; Di Marcantonio, P; Downing, M; Elswijk, E; Finger, G; Fischer, G; Flores, H; Francois, P; Goldoni, P; Guglielmi, L; Haigron, R; Hanenburg, H; Hendriks, I; Horrobin, M; Horville, D; Jessen, N C; Kerber, F; Kern, L; Kiekebusch, M; Kleszcz, P; Klougart, J; Kragt, J; Larsen, H H; Lizon, J -L; Lucuix, C; Mainieri, V; Manuputy, R; Martayan, C; Mason, E; Mazzoleni, R; Michaelsen, N; Modigliani, A; Moehler, S; Møller, P; Sørensen, A Norup; Nørregaard, P; Peroux, C; Patat, F; Pena, E; Pragt, J; Reinero, C; Riga, F; Riva, M; Roelfsema, R; Royer, F; Sacco, G; Santin, P; Schoenmaker, T; Spano, P; Sweers, E; Ter Horst, R; Tintori, M; Tromp, N; van Dael, P; van der Vliet, H; Venema, L; Vidali, M; Vinther, J; Vola, P; Winters, R; Wistisen, D; Wulterkens, G; Zacchei, A

    2011-01-01

    X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope(VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 to 2500 nm. It is designed to maximize the sensitivity in this spectral range through dichroic splitting in three arms with optimized optics, coatings, dispersive elements and detectors. It operates at intermediate spectral resolution (R~4,000 - 17,000, depending on wavelength and slit width) with fixed echelle spectral format (prism cross-dispersers) in the three arms. It includes a 1.8"x4" Integral Field Unit as an alternative to the 11" long slits. A dedicated data reduction package delivers fully calibrated two-dimensional and extracted spectra over the full wavelength range. We describe the main characteristics of the instrument and present its performance as measured during commissioning, science verification and ...

  9. Spectroradiometry with Space Telescopes

    CERN Document Server

    Pauluhn, Anuschka; Smith, Peter L; Colina, Luis

    2015-01-01

    Radiometry has been of fundamental importance in astronomy from the early beginnings. Initially, astronomers had their own radiometric system, based on extraterrestrial standards, namely the irradiance of stars expressed in visual magnitudes. Observing and comparing magnitudes in specific spectral bands then led to the astronomical spectrophotometry. The advent of astronomical high-resolution spectroscopy offered the possibility to interpret observations through physical models of stellar atmospheres. Such models had to be constructed based on physics-related units, and such units, rather than magnitudes, were then used for observational tests of the models. In this review, we provide an overview of how to achieve a valid laboratory calibration, and discuss ways to reliably extend this calibration to the spectroscopic telescope's performance in space. Recently, the quest for independent calibrations traceable to laboratory standards has become a well-supported aim, and has led to plans for now also launching ...

  10. Apollo Telescope Mount Spar Assembly

    Science.gov (United States)

    1969-01-01

    The Apollo Telescope Mount (ATM), designed and developed by the Marshall Space Flight Center, served as the primary scientific instrument unit aboard the Skylab. The ATM contained eight complex astronomical instruments designed to observe the Sun over a wide spectrum from visible light to x-rays. This image shows the ATM spar assembly. All solar telescopes, the fine Sun sensors, and some auxiliary systems are mounted on the spar, a cruciform lightweight perforated metal mounting panel that divides the 10-foot long canister lengthwise into four equal compartments. The spar assembly was nested inside a cylindrical canister that fit into the rack, a complex frame, and was protected by the solar shield.

  11. The Swift Mission and the REM Telescope

    Science.gov (United States)

    Gehrels, N.; Chincarini, G.; Giommi, P.; Mason, K. O.; Nousek, J. A.; Wells, A. A.; White, N. E.; Barthelemy, S. D.; Burrow, D. N.; Hurley, K. C.

    2003-01-01

    Following a description of the science drive which originated the Swift Mission, this is US NASA MIDEX Mission with the collaboration of Italy and the UK, we will describe the status of the hardware and the observing strategy. The telemetry is carried out via the TDRSS satellite for those communications that need immediate response. The data transfer and the scheduled uploading of routine commands will be done through the ASI Malindi station in Kenia. Both in the US and in Europe a large effort will be done to follow the bursts with the maximum of efficiency and as soon as possible after the alert. We will describe how the ESO VLT telescopes are able to respond to the alert. To address the problematic of the dark bursts and to immediately follow up all of the bursts also in the Near Infrared we designed and built a 60 cm NIR Robotic telescope, REM, to be located on the ESO ground at Cerro La Silla. The instrumentation includes also a low dispersion spectrograph with the capability of multi wavelength optical photometry.

  12. The Swift Mission and the REM Telescope

    Science.gov (United States)

    Gehrels, N.; Chincarini, G.; Giommi, P.; Mason, K. O.; Nousek, J. A.; Wells, A. A.; White, N. E.; Barthelemy, S. D.; Burrow, D. N.; Hurley, K. C.

    2003-01-01

    Following a description of the science drive which originated the Swift Mission, this is US NASA MIDEX Mission with the collaboration of Italy and the UK, we will describe the status of the hardware and the observing strategy. The telemetry is carried out via the TDRSS satellite for those communications that need immediate response. The data transfer and the scheduled uploading of routine commands will be done through the ASI Malindi station in Kenia. Both in the US and in Europe a large effort will be done to follow the bursts with the maximum of efficiency and as soon as possible after the alert. We will describe how the ESO VLT telescopes are able to respond to the alert. To address the problematic of the dark bursts and to immediately follow up all of the bursts also in the Near Infrared we designed and built a 60 cm NIR Robotic telescope, REM, to be located on the ESO ground at Cerro La Silla. The instrumentation includes also a low dispersion spectrograph with the capability of multi wavelength optical photometry.

  13. VLT imaging of the {\\beta} Pictoris gas disk

    CERN Document Server

    Nilsson, R; Olofsson, G; Fathi, K; Thébault, Ph; Liseau, R

    2012-01-01

    Circumstellar debris disks older than a few Myr should be largely devoid of primordial gas remaining from the protoplanetary disk phase. Tracing the origin of observed atomic gas in Keplerian rotation in the edge-on debris disk surrounding the ~12 Myr old star {\\beta} Pictoris requires more detailed information about its spatial distribution than has previously been acquired by limited slit spectroscopy. Especially indications of asymmetries and presence of Ca II gas at high disk latitudes call for additional investigation. We set out to recover a complete image of the Fe I and Ca II gas emission around {\\beta} Pic by spatially resolved, high-resolution spectroscopic observations to better understand the morphology and origin of the gaseous disk component. The multiple fiber facility FLAMES/GIRAFFE at the VLT, with the large IFU ARGUS, was used to obtain spatially resolved optical spectra in four regions covering the northeast and southwest side of the disk. Emission lines from Fe I and Ca II were mapped and ...

  14. MASSIVE STARS: FROM THE VLT TO THE ELT

    Directory of Open Access Journals (Sweden)

    Chris Evans

    2008-01-01

    Full Text Available Nuestro conocimiento de las estrellas masivas ha aumentado significativamente en los últimos 30 años gracias a las nuevas instalaciones y tecnologías. En esta contribución presento un gran survey de estrellas masivas que se ha realizado recientemente mediante el uso de VLT-FLAMES, mostrando los campos observados y remarcando la fracción de estrellas binarias que se ha encontrado. Estos datos se han utilizado para la primera comprobación empírica de la dependencia de la intensidad de los vientos estelares con la metalicidad, encontrándose un buen acuerdo con la teoría un resultado de gran importancia para los modelos de evolución estelar, que se utilizan para la interpretación de cúmulos lejanos, starburst y galaxias con formación estelar. Dando un paso más, comentaré como en la actualidad se están dedicando grandes esfuerzos al avance de los planes de actuación y desarrollo de los Telescopios de Gran Tamaño, que serán una realidad en un futuro próximo; este hecho nos ofrecerá una posibilidad más que interesante para obtener observaciones con resolución espacial de estrellas masivas más allá del Grupo Local.

  15. VLT spectroscopy of XTE J2123-058 during quiescence

    CERN Document Server

    Casares, J; Shahbaz, T; Zurita, C; Charles, P A

    2001-01-01

    We present VLT low resolution spectroscopy of the neutron star X-ray transient XTE J2123-058 during its quiescent state. Our data reveal the presence of a K7V companion which contributes 77 % to the total flux at 6300 A and orbits the neutron star at K_2 = 287 +/- 12 km/s. Contrary to other soft X-ray transients (SXTs), the Halpha emission is almost exactly in antiphase with the velocity curve of the optical companion. Using the light-center technique we obtain K_1 = 140 +/- 27 km/s and hence q=K_1/K_2=M_2/M_1= 0.49 +/- 0.10. This, combined with a previous determination of the inclination angle (i=73 +/- 4) yields M_1 = 1.55 +/- 0.31 Msun and M_2 = 0.76 +/- 0.22 Msun. M_2 agrees well with the observed spectral type. Doppler tomography of the Halpha emission shows a non-symmetric accretion disc distribution mimicking that seen in SW Sex stars. Although we find a large systemic velocity of -110 +/- 8 km/s this value is consistent with the galactic rotation velocity at the position of J2123-058, and hence a halo...

  16. Clumpy dust clouds and extended atmosphere of the AGB star W Hya revealed with VLT/SPHERE-ZIMPOL and VLTI/AMBER

    CERN Document Server

    Ohnaka, Keiichi; Hofmann, Karl-Heinz

    2016-01-01

    We present visible polarimetric imaging observations of the well-studied AGB star W Hya taken with VLT/SPHERE-ZIMPOL as well as high spectral resolution long-baseline interferometric observations with the AMBER instrument of the Very Large Telescope Interferometer (VLTI). We observed W Hya with VLT/SPHERE-ZIMPOL at three wavelengths in the continuum (645, 748, and 820 nm), in the Halpha line at 656.3 nm, and in the TiO band at 717 nm. The VLTI/AMBER observations were carried out in the wavelength region of the CO first overtone lines near 2.3 micron with a spectral resolution of 12000. Taking advantage of the polarimetric imaging capability of SPHERE-ZIMPOL combined with the superb adaptive optics performance, we have succeeded in spatially resolving three clumpy dust clouds located at ~50 mas (~2 Rstar) from the central star, revealing dust formation very close to the star. The AMBER data in the individual CO lines suggest a molecular outer atmosphere extending to ~3 Rstar. Furthermore, the SPHERE-ZIMPOL ima...

  17. Wind measurements in Saturn's atmosphere with UVES/VLT ground-based Doppler velocimetry

    Science.gov (United States)

    Machado, Pedro; Silva, Miguel; Peralta, Javier; Luz, David; Sánchez-Lavega, Agustin; Hueso, Ricardo

    2016-04-01

    We will present preliminary Doppler wind velocity results of Saturn's zonal flow at cloud level. Our aim is help to constrain the characterization of the equatorial jet at cloud level and the latitudinal variation of the zonal winds, to measure its spatial and temporal variability, to contribute to monitor the variability in order to achieve a better understanding of the dynamics of Saturn's zonal winds, whose equatorial jet has a complex vertical structure and temporal variability (Sanchez-Lavega et al., Nature, 423, 623, 3003; Garcia-Melendo et al., Geophys. Res. Lett., 37, L22204. 2010). Finally, the complementarity with Cassini, providing an independent set of observations. The UVES/VLT instrument has been used, which simultaneously achieves high spectral resolving power and high spatial resolution. The field has been derotated in order to have the aperture aligned perpendicularly to Saturn's rotation axis. In this configuration, spatial information in the East-West direction is preserved in a set of spectra in the direction perpendicular to dispersion. The technique of absolute accelerometry (AA, Connes, 1985, ApSS 110, 211) has been applied to the backscattered solar spectrum in order to determine the Doppler shift associated with the zonal circulation. Our measurements have been made in the wavelength range of 480-680 nm. Previously we successfully adapted this Doppler velocimetry technique for measuring winds at Venus cloud tops (Machado et al. 2012). In the present study we will show the adaptation of this method for Saturn's case. Since the AA technique only allows to compare spectra where the line shifts are within the line width, in fast rotating atmospheres (as is the case of Saturn) the spectra must be compared by pairs from adjacent areas of the disk (adjacent pixels in the slit). We will use coordinated observations from the Cassini's Visible and Infrared Mapping Spectrometer (VIMS), in order to compare with the Doppler winds obtained from the UVES/VLT

  18. The SOFIA Telescope

    CERN Document Server

    Krabbe, A

    2000-01-01

    The SOFIA telescope as the heart of the observatory is a major technological challenge. I present an overview on the astro-nomical and scientific requirements for such a big airborne observatory and demonstrate the impact of these requirements on the layout of SOFIA, in particular on the telescope design as it is now. Selected components of the telescope will be de-scribed in their context and functionality. The current status of the telescope is presented.

  19. Time variability of Neptune's horizontal and vertical cloud structure revealed by VLT/SINFONI and Gemini/NIFS from 2009 to 2013

    Science.gov (United States)

    Irwin, P. G. J.; Fletcher, L. N.; Tice, D.; Owen, S. J.; Orton, G. S.; Teanby, N. A.; Davis, G. R.

    2016-06-01

    New observations of Neptune's clouds in the near infrared were acquired in October 2013 with SINFONI on ESO's Very Large Telescope (VLT) in Chile. SINFONI is an Integral Field Unit spectrometer returning a 64 × 64 pixel image with 2048 wavelengths. Image cubes in the J-band (1.09-1.41 μm) and H-band (1.43-1.87 μm) were obtained at spatial resolutions of 0.1″and 0.025″per pixel, while SINFONI's adaptive optics provided an effective resolution of approximately 0.1″. Image cubes were obtained at the start and end of three successive nights to monitor the temporal development of discrete clouds both at short timescales (i.e. during a single night) as well as over the longer period of the three-day observing run. These observations were compared with similar H-band observations obtained in September 2009 with the NIFS Integral Field Unit spectrometer on the Gemini-North telescope in Hawaii, previously reported by Irwin et al. (2011) [Icarus, 216, 141-158], and previously unreported Gemini/NIFS observations at lower spatial resolution made in 2011. We find both similarities and differences between these observations, spaced over four years. The same overall cloud structure is seen with high, bright clouds visible at mid-latitudes (30-40°N,S), with slightly lower clouds observed at lower latitudes, together with small discrete clouds seen circling the pole at a latitude of approximately 60°S. However, while discrete clouds were visible at this latitude at both the main cloud deck level (at 2-3 bar) and in the upper troposphere (100-500 mb) in 2009, no distinct deep (2-3 bar), discrete circumpolar clouds were visible in 2013, although some deep clouds were seen at the southern edge of the main cloud belt at 30-40°S, which have not been observed before. The nature of the deep sub-polar discrete clouds observed in 2009 is intriguing. While it is possible that in 2013 these deeper clouds were masked by faster moving, overlying features, we consider that it is

  20. Advanced technology optical telescopes IV; Proceedings of the Meeting, Tucson, AZ, Feb. 12-16, 1990. Parts 1 & 2

    Science.gov (United States)

    Barr, Lawrence D. (Editor)

    1990-01-01

    The present conference on the current status of large, advanced-technology optical telescope development and construction projects discusses topics on such factors as their novel optical system designs, the use of phased arrays, seeing and site performance factors, mirror fabrication and testing, pointing and tracking techniques, mirror thermal control, structural design strategies, mirror supports and coatings, and the control of segmented mirrors. Attention is given to the proposed implementation of the VLT Interferometer, the first diffraction-limited astronomical images with adaptive optics, a fiber-optic telescope using a large cross-section image-transmitting bundle, the design of wide-field arrays, Hartmann test data reductions, liquid mirrors, inertial drives for telescope pointing, temperature control of large honeycomb mirrors, evaporative coatings for very large telescope mirrors, and the W. M. Keck telescope's primary mirror active control system software.

  1. High-Flying Telescope

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Scientists at the Space Telescope Science Institute,which operates the Hubble Space Telescope,have proposed a new telescope that would have twice the resolution of Hubble at about one-tenth the cost. It would hover seven miles above Earth,dangling below a football-field-size helium balloon

  2. Auto Adjusting Astronomical Telescope

    Directory of Open Access Journals (Sweden)

    Rohit R. Ghalsasi

    2014-04-01

    Full Text Available Astronomical telescope is powerful and basic tool for star or celestial observation. Here we proposed integrated system using Raspberry Pi for auto adjusting astronomical telescope. This integrated circuit helps to control stellar monitoring, stellar targeting, and tracking functions of telescope. Astro compass gives the direction of the celestial objects.

  3. ATST telescope mount: telescope of machine tool

    Science.gov (United States)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  4. The Cherenkov Telescope Array Large Size Telescope

    CERN Document Server

    Ambrosi, G; Baba, H; Bamba, A; Barceló, M; de Almeida, U Barres; Barrio, J A; Bigas, O Blanch; Boix, J; Brunetti, L; Carmona, E; Chabanne, E; Chikawa, M; Colin, P; Conteras, J L; Cortina, J; Dazzi, F; Deangelis, A; Deleglise, G; Delgado, C; Díaz, C; Dubois, F; Fiasson, A; Fink, D; Fouque, N; Freixas, L; Fruck, C; Gadola, A; García, R; Gascon, D; Geffroy, N; Giglietto, N; Giordano, F; Grañena, F; Gunji, S; Hagiwara, R; Hamer, N; Hanabata, Y; Hassan, T; Hatanaka, K; Haubold, T; Hayashida, M; Hermel, R; Herranz, D; Hirotani, K; Inoue, S; Inoue, Y; Ioka, K; Jablonski, C; Kagaya, M; Katagiri, H; Kishimoto, T; Kodani, K; Kohri, K; Konno, Y; Koyama, S; Kubo, H; Kushida, J; Lamanna, G; Flour, T Le; López-Moya, M; López, R; Lorenz, E; Majumdar, P; Manalaysay, A; Mariotti, M; Martínez, G; Martínez, M; Mazin, D; Miranda, J M; Mirzoyan, R; Monteiro, I; Moralejo, A; Murase, K; Nagataki, S; Nakajima, D; Nakamori, T; Nishijima, K; Noda, K; Nozato, A; Ohira, Y; Ohishi, M; Ohoka, H; Okumura, A; Orito, R; Panazol, J L; Paneque, D; Paoletti, R; Paredes, J M; Pauletta, G; Podkladkin, S; Prast, J; Rando, R; Reimann, O; Ribó, M; Rosier-Lees, S; Saito, K; Saito, T; Saito, Y; Sakaki, N; Sakonaka, R; Sanuy, A; Sasaki, H; Sawada, M; Scalzotto, V; Schultz, S; Schweizer, T; Shibata, T; Shu, S; Sieiro, J; Stamatescu, V; Steiner, S; Straumann, U; Sugawara, R; Tajima, H; Takami, H; Tanaka, S; Tanaka, M; Tejedor, L A; Terada, Y; Teshima, M; Totani, T; Ueno, H; Umehara, K; Vollhardt, A; Wagner, R; Wetteskind, H; Yamamoto, T; Yamazaki, R; Yoshida, A; Yoshida, T; Yoshikoshi, T

    2013-01-01

    The two arrays of the Very High Energy gamma-ray observatory Cherenkov Telescope Array (CTA) will include four Large Size Telescopes (LSTs) each with a 23 m diameter dish and 28 m focal distance. These telescopes will enable CTA to achieve a low-energy threshold of 20 GeV, which is critical for important studies in astrophysics, astroparticle physics and cosmology. This work presents the key specifications and performance of the current LST design in the light of the CTA scientific objectives.

  5. VizieR Online Data Catalog: CLASH-VLT: the FF cluster MACS J0416.1-2403 (Balestra+, 2016)

    Science.gov (United States)

    Balestra, I.; Mercurio, A.; Sartoris, B.; Girardi, M.; Grillo, C.; Nonino, M.; Rosati, P.; Biviano, A.; Ettori, S.; Forman, W.; Jones, C.; Koekemoer, A.; Medezinski, E.; Merten, J.; Ogrean, G. A.; Tozzi, P.; Umetsu, K.; Vanzella, E.; van Weeren, R. J.; Zitrin, A.; Annunziatella, M.; Caminha, G. B.; Broadhurst, T.; Coe, D.; Donahue, M.; Fritz, A.; Frye, B.; Kelson, D.; Lombardi, M.; Maier, C.; Meneghetti, M.; Monna, A.; Postman, M.; Scodeggio, M.; Seitz, S.; Ziegler, B.

    2016-07-01

    The cluster MACS J0416.1-2403 was observed between 2012 December and 2014 November as part of the ESO Large Programme 186.A-0798 "Dark Matter Mass Distributions of Hubble Treasury Clusters and the Foundations of ΛCDM Structure Formation Models" (P.I.: Piero Rosati) using VIMOS at the ESO VLT. A total of 21 masks were observed (15 LR-Blue (low-resolution) masks and 6 MR (medium-resolution) masks). The LR-Blue masks cover the spectral range 3700-6700Å with a resolution of R=180, while the MR masks cover the range 4800-10000Å with a resolution of R=580. The massive cluster has been observed with the Hubble Space Telescope (HST) as part of the Multi-Cycle Treasury program Cluster Lensing And Supernova survey with Hubble (CLASH; P.I.: M. Postman; Postman et al. 2012, J/ApJS/199/25). The HST survey is nicely complemented by Subaru wide-field imaging. (3 data files).

  6. Investigating the nature of the z~2.8 submillimeter selected galaxy SMM J02399-0136 with VLT spectropolarimetry

    CERN Document Server

    Vernet, J; Vernet, Joel; Cimatti, Andrea

    2001-01-01

    We present deep optical spectropolarimety of SMM J02399-0136 (z=2.8) done with the VLT Antu 8.2 m telescope equipped with FORS1. Moderate continuum and emission line polarization are measured (P~5%). We do not detect broad lines in scattered flux as would be expected for a type-2 object but rather a polarization behaviour similar to BAL quasars. This classification is confirmed by the detection of both high and low ionization broad absorption troughs and a very red continuum. We argue that this object shares several properties with local ULIGs such as Mrk 231 and other ultraluminous infrared Lo-BAL quasars. However, the fact that the ultraviolet spectrum is dominated by non-stellar radiation does not prove that the dust that is thermally radiating in the far infrared is predominantly heated by the AGN. Since the energy that we get in the far-infrared is precisely that which is removed from the ultraviolet spectrum, this could mean that the starburst is more dust-enshrouded than the AGN due to a peculiar dust ...

  7. Deep vlt spectroscopy of high redshift radio galaxy MRC 2104{242: evidence for a metallicity gradient

    Directory of Open Access Journals (Sweden)

    R. Overzier

    2002-01-01

    Full Text Available En esta contribuci on vamos a presentar observaciones espectrosc opicas profundas del VLT (siglas en ingl es: Very Large Telescope del halo gigante de l neas de emisi on alrededor de la radiogalaxia MRC 2104{242 a z = 2:49. La morfolog a del halo viene determinado por dos regiones espaciales resueltas. Ly se extiende por > 1200 a lo largo del radioeje, C IV 1549 y He II 1640 se extienden por 800. El espectro total es t pico para radiogalaxias de alto corrimiento al rojo. Es interesante notar que N V 1240 est a presente en el espectro de la regi on asociada con el centro de la galaxia que contiene la radiofuente, la regi on del norte, mientras que est a ausente en la regi on del sur. Usando un modelo de fotoionizaci on simple, la diferencia en la emisi on N V 1240 se puede explicar por un gradiente de metalicidad en el halo. Esto es consistente con un escenario en el cual el halo se form o por un "cooling ow" masivo o tiene su origen en los residuos de la fusi on de dos o m as galaxias. Sin embargo, tambi en podr an ser importantes otros mecanismos como son las interacciones entre jets y nubes y los vientos debido a un \\starburst".

  8. The Africa Millimetre Telescope

    Science.gov (United States)

    Backes, M.; Müller, C.; Conway, J. E.; Deane, R.; Evans, R.; Falcke, H.; Fraga-Encinas, R.; Goddi, C.; Klein Wolt, M.; Krichbaum, T. P.; MacLeod, G.; Ribeiro, V. A. R. M.; Roelofs, F.; Shen, Z. Q.; van Langevelde, H. J.

    It is believed that supermassive black holes are found in the centres of galaxies, including the Milky Way. Still, only indirect evidence has been gathered for the existence of these enigmatic objects that are predicted by the general theory of relativity. With the Event Horizon Telescope, a Very Long Baseline Interferometry network of millimetre-wave (radio) telescopes, it will be possible to directly image the 'shadow' of the event horizon of the black hole at the centre of the Milky Way, Sgr A*. Although the Event Horizon Telescope utilises an extensive network of telescopes, there is a huge gap in the coverage of the u-v-plane for these observations across Africa. We discuss the benefits of adding the Africa Millimetre Telescope to the Event Horizon Telescope and present Mt. Gamsberg in Namibia as the best site for this new and first mm-wave telescope in Africa.

  9. CLASH-VLT: testing the nature of gravity with galaxy cluster mass profiles

    Science.gov (United States)

    Pizzuti, L.; Sartoris, B.; Borgani, S.; Amendola, L.; Umetsu, K.; Biviano, A.; Girardi, M.; Rosati, P.; Balestra, I.; Caminha, G. B.; Frye, B.; Koekemoer, A.; Grillo, C.; Lombardi, M.; Mercurio, A.; Nonino, M.

    2016-04-01

    We use high-precision kinematic and lensing measurements of the total mass profile of the dynamically relaxed galaxy cluster MACS J1206.2-0847 at z=0.44 to estimate the value of the ratio η=Ψ/Φ between the two scalar potentials in the linear perturbed Friedmann-Lemaitre-Robertson-Walker metric. An accurate measurement of this ratio, called anisotropic stress, could show possible, interesting deviations from the predictions of the theory of General Relativity, according to which Ψ should be equal to Φ. Complementary kinematic and lensing mass profiles were derived from exhaustive analyses using the data from the Cluster Lensing And Supernova survey with Hubble (CLASH) and the spectroscopic follow-up with the Very Large Telescope (CLASH-VLT). Whereas the kinematic mass profile tracks only the time-time part of the perturbed metric (i.e. only Φ), the lensing mass profile reflects the contribution of both time-time and space-space components (i.e. the sum Φ+Ψ). We thus express η as a function of the mass profiles and perform our analysis over the radial range 0.5 MpcFrenk-White mass profile, which well fits the data, we obtain η(r200)=1.01 -0.28+0.31 at the 68% C.L. We discuss the effect of assuming different functional forms for mass profiles and of the orbit anisotropy in the kinematic reconstruction. Interpreting this result within the well-studied f(R) modified gravity model, the constraint on η translates into an upper bound to the interaction length (inverse of the scalaron mass) smaller than 2 Mpc. This tight constraint on the f(R) interaction range is however substantially relaxed when systematic uncertainties in the analysis are considered. Our analysis highlights the potential of this method to detect deviations from general relativity, while calling for the need of further high-quality data on the total mass distribution of clusters and improved control on systematic effects.

  10. Liverpool Telescope and Liverpool Telescope 2

    Science.gov (United States)

    Copperwheat, C. M.; Steele, I. A.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Jermak, H.; Marchant, J. M.; Mottram, C. J.; Piascik, A.; Smith, R. J.

    2016-12-01

    The Liverpool Telescope is a fully robotic optical/near-infrared telescope with a 2-metre clear aperture, located at the Observatorio del Roque de los Muchachos on the Canary Island of La Palma. The telescope is owned and operated by Liverpool John Moores University, with financial support from the UK's Science and Technology Facilities Council. The telescope began routine science operations in 2004 and is a common-user facility with time available through a variety of committees via an open, peer reviewed process. Seven simultaneously mounted instruments support a broad science programme, with a focus on transient follow-up and other time domain topics well suited to the characteristics of robotic observing. Development has also begun on a successor facility, with the working title `Liverpool Telescope 2', to capitalise on the new era of time domain astronomy which will be brought about by the next generation of survey facilities such as LSST. The fully robotic Liverpool Telescope 2 will have a 4-metre aperture and an improved response time. In this paper we provide an overview of the current status of both facilities.

  11. 3D shape of asteroid (6) Hebe from VLT/SPHERE imaging: Implications for the origin of ordinary H chondrites

    Science.gov (United States)

    Marsset, M.; Carry, B.; Dumas, C.; Hanuš, J.; Viikinkoski, M.; Vernazza, P.; Müller, T. G.; Delbo, M.; Jehin, E.; Gillon, M.; Grice, J.; Yang, B.; Fusco, T.; Berthier, J.; Sonnett, S.; Kugel, F.; Caron, J.; Behrend, R.

    2017-08-01

    Context. The high-angular-resolution capability of the new-generation ground-based adaptive-optics camera SPHERE at ESO VLT allows us to assess, for the very first time, the cratering record of medium-sized (D 100-200 km) asteroids from the ground, opening the prospect of a new era of investigation of the asteroid belt's collisional history. Aims: We investigate here the collisional history of asteroid (6) Hebe and challenge the idea that Hebe may be the parent body of ordinary H chondrites, the most common type of meteorites found on Earth ( 34% of the falls). Methods: We observed Hebe with SPHERE as part of the science verification of the instrument. Combined with earlier adaptive-optics images and optical light curves, we model the spin and three-dimensional (3D) shape of Hebe and check the consistency of the derived model against available stellar occultations and thermal measurements. Results: Our 3D shape model fits the images with sub-pixel residuals and the light curves to 0.02 mag. The rotation period (7.274 47 h), spin (ECJ2000 λ, β of 343°, +47°), and volume-equivalent diameter (193 ± 6 km) are consistent with previous determinations and thermophysical modeling. Hebe's inferred density is 3.48 ± 0.64 g cm-3, in agreement with an intact interior based on its H-chondrite composition. Using the 3D shape model to derive the volume of the largest depression (likely impact crater), it appears that the latter is significantly smaller than the total volume of close-by S-type H-chondrite-like asteroid families. Conclusions: Our results imply that (6) Hebe is not the most likely source of H chondrites. Over the coming years, our team will collect similar high-precision shape measurements with VLT/SPHERE for 40 asteroids covering the main compositional classes, thus providing an unprecedented dataset to investigate the origin and collisional evolution of the asteroid belt. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory

  12. Toward accurate radial velocities with the fiber-fed GIRAFFE multi-object VLT spectrograph

    Science.gov (United States)

    Royer, Frederic; Blecha, Andre; North, Pierre; Simond, Gilles; Baratchart, Sebastien; Cayatte, Veronique; Chemin, Laurent; Palsa, Ralf

    2002-12-01

    We describe briefly the Data-Reduction of the VLT fiber-fed multi-object GIRAFFE spectrograph - part of the VLT FLAMES facility. We focus on specific features of GIRAFFE - the simultaneous wavelength calibration - and their impact on the data-reduction strategy. We describe the implementation of the global physical model and we compare the results obtained with the simulated, laboratory and preliminary data. We discuss the influence of critical parameters, the overall accuracy of the wavelength solution, and the stability and the robustness of the global model approach. We address the accuracy of radial velocity measurements illustrated by solar spectra obtained during the Preliminary Acceptance in Europe.

  13. The Solar Telescope GREGOR

    Science.gov (United States)

    Volkmer, R.

    2008-09-01

    During the last years the new 1.5m solar telescope GREGOR was assembled at Izania on Tenerife, Spain. The telescope is designed for high-precision measurements of the magnetic field in the solar photosphere and chromosphere with a resolution of 70km on the Sun. The telescope concept offers also high resolution stellar spectroscopy. The telescope is build by a consortium of the Kiepenheuer-Institut für Sonnenphysik, the Astrophysikalische Institut Potsdam, the Institut für Astrophysik Göttingen, Max-Plank-Institut für Sonnensystemforschung and additional international Partners. The telescope is a complete open structure with active cooled main mirror. High performance post-focus instruments in the visible and near IR wavelength acquire high resolution spectra with 2 dimensional spatial resolution and polarimetric information. The commissioning of the telescope will start in 2008 to allow first science observations at the end of 2009.

  14. JWST Pathfinder Telescope Integration

    Science.gov (United States)

    Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.; McKay, Andrew; Levi, Joshua; Keski-Kuha, Ritva; Feinberg, Lee

    2015-01-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. In 2014, a major risk reduction effort related to the Alignment, Integration, and Test (AI&T) of the segmented telescope was completed. The Pathfinder telescope includes two Primary Mirror Segment Assemblies (PMSA's) and the Secondary Mirror Assembly (SMA) onto a flight-like composite telescope backplane. This pathfinder allowed the JWST team to assess the alignment process and to better understand the various error sources that need to be accommodated in the flight build. The successful completion of the Pathfinder Telescope provides a final integration roadmap for the flight operations that will start in August 2015.

  15. The VLT Adaptive Optics Facility Project: Adaptive Optics Modules

    Science.gov (United States)

    Arsenault, Robin; Hubin, Norbert; Stroebele, Stefan; Fedrigo, Enrico; Oberti, Sylvain; Kissler-Patig, Markus; Bacon, Roland; McDermid, Richard; Bonaccini-Calia, Domenico; Biasi, Roberto; Gallieni, Daniele; Riccardi, Armando; Donaldson, Rob; Lelouarn, Miska; Hackenberg, Wolfgang; Conzelman, Ralf; Delabre, Bernard; Stuik, Remko; Paufique, Jerome; Kasper, Markus; Vernet, Elise; Downing, Mark; Esposito, Simone; Duchateau, Michel; Franx, Marijn; Myers, Richard; Goodsell, Steven

    2006-03-01

    The Adaptive Optics Facility is a project to convert UT4 into a specialised Adaptive Telescope with the help of a Deformable Secondary Mirror (see previous article). The two instruments that have been identified for the two Nasmyth foci are: Hawk-I with its AO module GRAAL allowing a Ground Layer Adaptive Optics correction (GLAO) and MUSE with GALACSI for GLAO correction and Laser Tomography Adaptive Optics correction. This article describes the AO modules GRAAL and GALACSI and their Real-Time Computers based on SPARTA.

  16. The great Melbourne telescope

    CERN Document Server

    Gillespie, Richard

    2011-01-01

    Erected at Melbourne Observatory in 1869, the telescope was the second largest in the world, designed to explore the nature of the nebulae in the southern skies. Richard Gillespie, head of the History and Technology department at the Melbourne museum has written an entertaining account of the telescope's extraordinary history and tells the story through an amazing cast of characters whose lives intersected with the telescope.

  17. Pointing a solar telescope

    Science.gov (United States)

    Wallace, Patrick

    2016-07-01

    As far as pointing is concerned, a solar telescope is merely an ordinary astronomical telescope but with enhancements for observing solar and coronal features. The paper discusses the additional coordinate systems that need to be supported, shows how to generate the required solar ephemerides (both orbital and physical), and sets out a suitable application programming interface for the telescope control system to use when making solar observations.

  18. The First VERITAS Telescope

    CERN Document Server

    Holder, J; Badran, H M; Blaylock, G; Bradbury, S M; Buckley, J H; Byrum, K L; Carter-Lewis, D A; Celik, O; Chow, Y C K; Cogan, P; Cui, W; Daniel, M K; De la Calle-Perez, I; Dowdall, C; Dowkontt, P; Duke, C; Falcone, A D; Fegan, S J; Finley, J P; Fortin, P; Fortson, L F; Gibbs, K; Gillanders, G; Glidewell, O J; Grube, J; Gutíerrez, K J; Gyuk, G; Hall, J; Hanna, D; Hays, E; Horan, D; Hughes, S B; Humensky, T B; Imran, A; Jung, I; Kaaret, Philip; Kenny, G E; Kieda, D; Kildea, J; Knapp, J; Krawczynski, H; Krennrich, F; Lang, M J; Le Bohec, S; Linton, E; Little, E K; Maier, G; Manseri, H; Milovanovic, A; Moriarty, P; Mukherjee, R; Ogden, P A; Ong, R A; Perkins, J S; Pizlo, F; Pohl, M; Quinn, J; Ragan, K; Reynolds, P T; Roache, E T; Rose, H J; Schroedter, M; Sembroski, G H; Sleege, G A; Steele, D; Swordy, S P; Syson, A; Toner, J A; Valcarcel, L; Vasilev, V V; Wagner, R; Wakely, S P; Weekes, T C; White, R J; Williams, D A

    2006-01-01

    The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic Radiation Imaging Telescope Array System) has been in operation since February 2005. We present here a technical description of the instrument and a summary of its performance. The calibration methods are described, along with the results of Monte Carlo simulations of the telescope and comparisons between real and simulated data. The analysis of TeV $\\gamma$-ray observations of the Crab Nebula, including the reconstructed energy spectrum, is shown to give results consistent with earlier measurements. The telescope is operating as expected and has met or exceeded all design specifications.

  19. LUTE telescope structural design

    Science.gov (United States)

    Ruthven, Gregory

    1993-01-01

    The major objective of the Lunar Ultraviolet Transit Experiment (LUTE) Telescope Structural Design Study was to investigate the feasibility of designing an ultralightweight 1-m aperture system within optical performance requirements and mass budget constraints. This study uses the results from our previous studies on LUTE as a basis for further developing the LUTE structural architecture. After summarizing our results in Section 2, Section 3 begins with the overall logic we used to determine which telescope 'structural form' should be adopted for further analysis and weight estimates. Specific telescope component analysis showing calculated fundamental frequencies and how they compare with our derived requirements are included. 'First-order' component stress analyses to ensure telescope optical and structural component (i.e. mirrors & main bulkhead) weights are realistic are presented. Layouts of both the primary and tertiary mirrors showing dimensions that are consistent with both our weight and frequency calculations also form part of Section 3. Section 4 presents our calculated values for the predicted thermally induced primary-to-secondary mirror despace motion due to the large temperature range over which LUTE must operate. Two different telescope design approaches (one which utilizes fused quartz metering rods and one which assumes the entire telescope is fabricated from beryllium) are considered in this analysis. We bound the secondary mirror focus mechanism range (in despace) based on these two telescope configurations. In Section 5 we show our overall design of the UVTA (Ultraviolet Telescope Assembly) via an 'exploded view' of the sub-system. The 'exploded view' is annotated to help aid in the understanding of each sub-assembly. We also include a two view layout of the UVTA from which telescope and telescope component dimensions can be measured. We conclude our study with a set of recommendations not only with respect to the LUTE structural architecture

  20. zCOSMOS : A large VLT/VIMOS redshift survey covering 0

    NARCIS (Netherlands)

    Lilly, S. J.; Le Fevre, O.; Renzini, A.; Zamorani, G.; Scodeggio, M.; Contini, T.; Carollo, C. M.; Hasinger, G.; Kneib, J.-P.; Iovino, A.; Le Brun, V.; Maier, C.; Mainieri, V.; Mignoli, M.; Silverman, J.; Tasca, L. A. M.; Bolzonella, M.; Bongiorno, A.; Bottini, D.; Capak, P.; Caputi, K.; Cimatti, A.; Cucciati, O.; Daddi, E.; Feldmann, R.; Franzetti, P.; Garilli, B.; Guzzo, L.; Ilbert, O.; Kampczyk, P.; Kovac, K.; Lamareille, F.; Leauthaud, A.; Le Borgne, J.-F.; McCracken, H. J.; Marinoni, C.; Pello, R.; Ricciardelli, E.; Scarlata, C.; Vergani, D.; Sanders, D. B.; Schinnerer, E.; Scoville, N.; Taniguchi, Y.; Arnouts, S.; Aussel, H.; Bardelli, S.; Brusa, M.; Cappi, A.; Ciliegi, P.; Finoguenov, A.; Foucaud, S.; Franceschini, R.; Halliday, C.; Impey, C.; Knobel, C.; Koekemoer, A.; Kurk, J.; Maccagni, D.; Maddox, S.; Marano, B.; Marconi, G.; Meneux, B.; Mobasher, B.; Moreau, C.; Peacock, J. A.; Porciani, C.; Pozzetti, L.; Scaramella, R.; Schiminovich, D.; Shopbell, P.; Smail, I.; Thompson, D.; Tresse, L.; Vettolani, G.; Zanichelli, A.; Zucca, E.

    2007-01-01

    zCOSMOS is a large-redshift survey that is being undertaken in the COSMOS field using 600 hr of observation with the VIMOS spectrograph on the 8mVLT. The survey is designed to characterize the environments of COSMOS galaxies from the 100 kpc scales of galaxy groups up to the 100 Mpc scale of the cos

  1. Motion control solution for new PLC-based standard development platform for VLT instrument control systems

    Science.gov (United States)

    Popovic, D.; Brast, R.; Di Lieto, N.; Kiekebusch, M.; Knudstrup, J.; Lucuix, C.

    2014-07-01

    More than a decade ago, due to obsolescence issues, ESO initiated the design and implementation of a custom-made CANbus based motion controller (CAN-RMC) to provide, together with a tailor-made software library (motor library), the motion control capabilities for the VME platform needed for the second generation VLT/VLTI instruments. The CAN-RMC controller has been successfully used in a number of VLT instruments but it has high production costs compared to the commercial off-the-shelf (COTS) industrial solutions available on the market today. In the scope of the selection of a new PLC-based platform for the VLT instrument control systems, ESO has evaluated motion control solutions from the company Beckhoff. This paper presents the investigation, implementation and testing of the PLC/TwinCAT/EtherCAT motion controllers for DC and stepper motors and their adaptation and integration into the VLT instrumentation framework. It reports functional and performance test results for the most typical use cases of astronomical instruments like initialization sequences, tracking, switch position detections, backslash compensation, brake handling, etc. In addition, it gives an overview of the main features of TwinCAT NC/PTP, PLCopen MC, EtherCAT motion control terminals and the engineering tools like TwinCAT Scope that are integrated into the development environment and simplify software development, testing and commissioning of motorized instrument functions.

  2. The VLT-FLAMES Tarantula Survey: I. Introduction and observational overview

    NARCIS (Netherlands)

    Evans, C.J.; Taylor, W.D.; Hénault-Brunet, V.; Sana, H.A.A.; de Koter, A.; Simón-Díaz, S.; Carraro, G.; Bagnoli, T.; Bastian, N.; Bestenlehner, J.M.; Bonanos, A.Z.; Bressert, E.; Brott, I.; Campbell, M.A.; Cantiello, M.; Clark, J.S.; Costa, E.; Crowther, P.A.; de Mink, S.E.; Doran, E.; Dufton, P.L.; Dunstall, P.R.; Friedrich, K.; Garcia, M.; Gieles, M.; Gräfener, G.; Herrero, A.; Howarth, I.D.; Izzard, R.G.; Langer, N.; Lennon, D.J.; Maiz Apellániz, J.; Markova, N.; Najarro, F.; Puls, J.; Ramirez, O.H.; Sabín-Sanjulián, C.; Smartt, S.J.; Stroud, V.E.; van Loon, J.T.; Vink, J.S.; Walborn, N.R.

    2011-01-01

    The VLT-FLAMES Tarantula Survey (VFTS) is an ESO Large Programme that has obtained multi-epoch optical spectroscopy of over 800 massive stars in the 30 Doradus region of the Large Magellanic Cloud (LMC). Here we introduce our scientific motivations and give an overview of the survey targets, includi

  3. The VLT-FLAMES Tarantula Survey. I. Introduction and observational overview

    NARCIS (Netherlands)

    Evans, C.J.; Taylor, W.D.; de Koter, A.; Brott, I.; Walborn, N.R.

    2011-01-01

    The VLT-FLAMES Tarantula Survey (VFTS) is an ESO Large Programme that has obtained multi-epoch optical spectroscopy of over 800 massive stars in the 30 Doradus region of the Large Magellanic Cloud (LMC). Here we introduce our scientific motivations and give an overview of the survey targets, includi

  4. Alcohol affects video lottery terminal (VLT) gambling behaviors and cognitions differently.

    Science.gov (United States)

    Ellery, Michael; Stewart, Sherry H

    2014-03-01

    People frequently combine alcohol use and gambling. However, our understanding of the effects of alcohol on gambling behavior is limited, both in terms of what the effects are and how they occur. The effects of a moderately intoxicating dose of alcohol (i.e., a blood alcohol concentration of .06 g%) on the video lottery terminal (VLT) gambling behaviors and cognitions of community-recruited nonpathological (n = 30) and probable pathological gamblers (n = 30) were compared. Alcohol increased the rate of double up betting (i.e., choosing to play a bonus game, after a winning video poker hand, which involves trying to pick a higher ranked card than the dealer's card from among 5 face down cards) of probable pathological gamblers, but did not influence their irrational beliefs about VLT play. Alcohol maintained the irrational beliefs about VLT play of nonpathological gamblers, but did not influence their gambling behaviors. Results are consistent with a growing body of research finding that gambling cognitions have an equivocal role in explaining actual gambling behaviors. Potential mechanisms for the observed effects are discussed. Applied implications discussed include: educating regular VLT players about the effects of alcohol on irrational gambling cognitions; reconsidering policies and practices that make alcohol available where machine gambling takes place; and targeting even moderate alcohol use in the treatment of gambling problems.

  5. The VLT-FLAMES Tarantula Survey. XXII. Multiplicity properties of the B-type stars

    NARCIS (Netherlands)

    Dunstall, P.R.; Dufton, P.L.; Sana, H.; Evans, C.J.; Howarth, I.D.; Simón-Díaz, S.; de Mink, S.E.; Langer, N.; Maíz Apellániz, J.; Taylor, W.D.

    2015-01-01

    We investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to estimate relative radial velocities from the helium and metal

  6. Athermal design of the optical tube assemblies for the ESO VLT four laser guidestar facility

    NARCIS (Netherlands)

    Henselmans, R.; Nijkerk, M.D.; Lemmen, M.H.J.; Rijnveld, N.; Kamphues, F.G.

    2011-01-01

    TNO is developing the Optical Tube Asssemblies (OTAs) for the ESO VLT Four Laser Guide Star Facility. The OTAs are Galilean 20x beam expanders, expanding a Ø15 mm input beam to a steerable Ø300 mm output beam with a wavefront quality requirement of 50 nm rms. The allowed defocus under the influence

  7. Water-filled telescopes

    CERN Document Server

    Antonello, E

    2014-01-01

    In this short note we discuss the case of the thought experiments on water-filled telescopes and their realizations during 18th and 19th century. The story of those instruments shows that the scientific progress occurs in a curious way, since there was no stringent reason for the construction of a water-filled telescope.

  8. Observing the Sun with Coronado telescopes telescopes

    CERN Document Server

    Pugh, Philip

    2007-01-01

    The Sun provides amateur astronomers with one of the few opportunities for daytime astronomy. In order to see the major features of our nearest star, special telescopes that have a very narrow visible bandwidth are essential. The bandwidth has to be as narrow as 1 A- 10-10 m (1 Angstrom) and centred on the absorption line of neutral hydrogen. This makes many major features of the Suna (TM)s chromosphere visible to the observer. Such narrow-band "Fabry-Perot etalon filters" are high technology, and until the introduction of the Coronado range of solar telescopes, were too expensive for amateur use. The entry-level Coronado telescope, the PST (Personal Solar Telescope) costs under 500. Solar prominences (vast columns of plasma, best seen at the edge of the solar disk), filaments, flares, sunspots, plage and active regions are all visible and can be imaged to produce spectacular solar photographs. Philip Pugh has assembled a team of contributors who show just how much solar work can be done with Coronado telesco...

  9. Shape model of asteroid (130) Elektra from optical photometry and disk-resolved images from VLT/SPHERE and Nirc2/Keck

    CERN Document Server

    Hanus, Josef; Viikinkoski, Matti; Yang, Bin; Kaasalainen, Mikko

    2016-01-01

    Asteroid (130) Elektra belongs to one of the six known triple asteroids in the main belt, so its mass has been reliably determined. We aim to use all available disk-resolved images of (130) Elektra obtained by the SPHERE instrument at VLT and by the Nirc2 of the Keck telescope together with the disk-integrated photometry to determine its shape model and its size. The volume can be then used in combination with the known mass to derive the bulk density of the primary. We apply the All-Data Asteroid Modeling (ADAM) algorithm to the optical disk-integrated data, 2 disk-resolved images obtained by the SPHERE instrument and 13 disk-resolved images from the Nirc2 of the Keck telescope, and derive the shape model and size of Elektra. We present the shape model, volume-equivalent diameter (199$\\pm$7 km) and bulk density (1.60$\\pm$0.13 g cm$^{-3}$) of the C-type asteroid Elektra.

  10. Frontier Fields : Combining HST, VLT and Spitzer data to explore the $z$$\\sim$8 Universe behind the lensing cluster MACS0416$-$2403

    CERN Document Server

    Laporte, N; Kim, S; Pelló, R; Bauer, F E; Bina, D; Brammer, G; De Leo, M A; Infante, L; Pérez-Fournon, I

    2014-01-01

    (Abridged) The HST Frontier Fields project started at the end of 2013 with the aim of providing extremely deep images of 6 massive galaxy clusters. One of the main goals of this program is to push several telescopes to their limits in order to provide the best current view of the earliest stages of the Universe. We present a detailed analysis of $z$$\\sim$8 objects behind the HFFs lensing cluster, MACS0416-2403, combining 0.3-1.6 $\\mu$m imaging from HST, ground-based $K_s$ imaging from VLT HAWK-I, and 3.6 $\\mu$m and 4.5 $\\mu$m Spitzer Space Telescope. We apply the classical Lyman Break technique, combining non-detection criteria and color-selection. In order to avoid contamination by mid-$z$ interlopers, we require a strong break between optical and near infrared data. The luminosity function at $z$$\\sim$8 is computed using a MC method taking advantage of the SED-fitting results. A piece of cautionary information is gleaned from new deep optical photometry of a previously identified $z$$\\sim$8 galaxy in this c...

  11. First light of the VLT planet finder SPHERE. II. The physical properties and the architecture of the young systems PZ Telescopii and HD 1160 revisited

    Science.gov (United States)

    Maire, A.-L.; Bonnefoy, M.; Ginski, C.; Vigan, A.; Messina, S.; Mesa, D.; Galicher, R.; Gratton, R.; Desidera, S.; Kopytova, T. G.; Millward, M.; Thalmann, C.; Claudi, R. U.; Ehrenreich, D.; Zurlo, A.; Chauvin, G.; Antichi, J.; Baruffolo, A.; Bazzon, A.; Beuzit, J.-L.; Blanchard, P.; Boccaletti, A.; de Boer, J.; Carle, M.; Cascone, E.; Costille, A.; De Caprio, V.; Delboulbé, A.; Dohlen, K.; Dominik, C.; Feldt, M.; Fusco, T.; Girard, J. H.; Giro, E.; Gisler, D.; Gluck, L.; Gry, C.; Henning, T.; Hubin, N.; Hugot, E.; Jaquet, M.; Kasper, M.; Lagrange, A.-M.; Langlois, M.; Le Mignant, D.; Llored, M.; Madec, F.; Martinez, P.; Mawet, D.; Milli, J.; Möller-Nilsson, O.; Mouillet, D.; Moulin, T.; Moutou, C.; Origné, A.; Pavlov, A.; Petit, C.; Pragt, J.; Puget, P.; Ramos, J.; Rochat, S.; Roelfsema, R.; Salasnich, B.; Sauvage, J.-F.; Schmid, H. M.; Turatto, M.; Udry, S.; Vakili, F.; Wahhaj, Z.; Weber, L.; Wildi, F.

    2016-03-01

    Context. The young systemsPZ Tel and HD 1160, hosting known low-mass companions, were observed during the commissioning of the new planet finder of the Very Large Telescope (VLT) SPHERE with several imaging and spectroscopic modes. Aims: We aim to refine the physical properties and architecture of both systems. Methods: We use SPHERE commissioning data and dedicated Rapid Eye Mount (REM) observations, as well as literature and unpublished data from VLT/SINFONI, VLT/NaCo, Gemini/NICI, and Keck/NIRC2. Results: We derive new photometry and confirm the short-term (P = 0.94 d) photometric variability of the star PZ Tel A with values of 0.14 and 0.06 mag at optical and near-infrared wavelengths, respectively. We note from the comparison to literature data spanning 38 yr that the star also exhibits a long-term variability trend with a brightening of ~0.25 mag. The 0.63-3.8 μm spectral energy distribution of PZ Tel B (separation ~25 AU) allows us to revise its physical characteristics: spectral type M7 ± 1, Teff = 2700 ± 100 K, log(g) 0.66). For eccentricities below 0.9, the inclination, longitude of the ascending node, and time of periastron passage are well constrained. In particular, both star and companion inclinations are compatible with a system seen edge-on. Based on "hot-start" evolutionary models, we reject other brown dwarf candidates outside 0.25'' for both systems, and giant planet companions outside 0.5'' that are more massive than 3 MJ for the PZ Tel system. We also show that K1-K2 color can be used along with YJH low-resolution spectra to identify young L-type companions, provided high photometric accuracy (≤0.05 mag) is achieved. Conclusions: SPHERE opens new horizons in the study of young brown dwarfs and giant exoplanets using direct imaging thanks to high-contrast imaging capabilities at optical (0.5-0.9 μm) and near-infrared (0.95-2.3 μm) wavelengths, as well as high signal-to-noise spectroscopy in the near-infrared domain (0.95-2.3 μm) from low

  12. Two Easily Made Astronomical Telescopes.

    Science.gov (United States)

    Hill, M.; Jacobs, D. J.

    1991-01-01

    The directions and diagrams for making a reflecting telescope and a refracting telescope are presented. These telescopes can be made by students out of plumbing parts and easily obtainable, inexpensive, optical components. (KR)

  13. The James Webb Space Telescope

    Science.gov (United States)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  14. CLASH-VLT: constraints on f(R) gravity models with galaxy clusters using lensing and kinematic analyses

    Science.gov (United States)

    Pizzuti, L.; Sartoris, B.; Amendola, L.; Borgani, S.; Biviano, A.; Umetsu, K.; Mercurio, A.; Rosati, P.; Balestra, I.; Caminha, G. B.; Girardi, M.; Grillo, C.; Nonino, M.

    2017-07-01

    We perform a maximum likelihood kinematic analysis of the two dynamically relaxed galaxy clusters MACS J1206.2-0847 at z=0.44 and RXC J2248.7-4431 at z=0.35 to determine the total mass profile in modified gravity models, using a modified version of the MAMPOSSt code of Mamon, Biviano and Bou&apose. Our work is based on the kinematic and lensing mass profiles derived using the data from the Cluster Lensing And Supernova survey with Hubble (hereafter CLASH) and the spectroscopic follow-up with the Very Large Telescope (hereafter CLASH-VLT). We assume a spherical Navarro-Frenk-White (NFW hereafter) profile in order to obtain a constraint on the fifth force interaction range λ for models in which the dependence of this parameter on the environment is negligible at the scale considered (i.e. λ=const) and fixing the fifth force strength to the value predicted in f(R) gravity. We then use information from lensing analysis to put a prior on the other NFW free parameters. In the case of MACSJ 1206 the joint kinematic+lensing analysis leads to an upper limit on the effective interaction range λdistribution. For RXJ 2248 instead a possible tension with the ΛCDM model appears when adding lensing information, with a lower limit λ>=0.14 mpc at Δχ2=2.71. This is consequence of the slight difference between the lensing and kinematic data, appearing in GR for this cluster, that could in principle be explained in terms of modifications of gravity. We discuss the impact of systematics and the limits of our analysis as well as future improvements of the results obtained. This work has interesting implications in view of upcoming and future large imaging and spectroscopic surveys, that will deliver lensing and kinematic mass reconstruction for a large number of galaxy clusters.

  15. The AMANDA neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Andres, E.C.; Askebjer, P.; Barwick, S.W.; Bay, R.C.; Bergstrom,L.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Carius, S.; Carlson,M.; Chinowsky, W.; Chirkin, D.; Conrad,J.; Costa, C.G.S.; Cowen, D.; Dalberg, E.; DeYoung, T.; Edsjo, J.; Ekstrom, P.; Goobar, A.; Gray, L.; Hallgren, A.; Halzen, F.; Hardtke, R.; Hart, S.; He, Y.; de, los, Heros,C.P.; Hill, G.; Hulth, PO.; Hundertmark, S.; Jacobsen, J.; Jones, A.; Kandhadai, V.; Karle, A.; Kim, J.; Leich, H.; Leuthold, M.; Lindahl, P.; Liubarsky, I.; Loaiza, P.; Lowder, D.; Marciniewski, P.; Miller, T.C.; Miocinovic, P.; Mock, P.C.; Morse, R.; Newcomer, M.; Niessen, P.; Nygren,D.; Porrata, R.; Potter, D.; Price, P.B.; Przybylski, G.; Rhode, W.; Richter, S.; Rodriguez, J.; Romenesko, P.; Ross, D.; Rubinstein, H.; Schmidt, T.; Schneider, E.; Schwarz, R.; Schwendicke, U.; Smoot, G.; Solarz, M.; Sorin, V.; Spiering, C.; Steffen, P.; Stokstad, R.; Streicher, O.; Taboada, I.; Thon, T.; Tilav, S.; Walck, C.; Wiebusch,C.H.; Wischnewski, R.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S.; AMANDACollaboration

    1999-04-01

    With an effective telescope area of order 10(4) m(2) for TeVneutrinos, a threshold near similar to 50 GeV and a pointing accuracy of2.5 degrees per muon track, the AMANDA detector represents the first of anew generation of high energy neutrino telescopes, reaching a scaleenvisaged over 25 years ago. We describe early results on the calibrationof natural deep ice as a particle detector as well as on AMANDA'sperformance as a neutrino telescope.

  16. The AMANDA neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Andres, E.C.; Askebjer, P.; Barwick, S.W.; Bay, R.C.; Bergstroem, L.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Carius, S.; Carlson, M.; Chinowsky, W.; Chirkin, D.; Conrad, J.; Costa, C.G.S.; Cowen, D.; Dalberg, E.; DeYoung, T.; Edsjoe, J.; Ekstroem, P.; Goobar, A.; Gray, L.; Hallgren, A.; Halzen, F.; Hardtke, R.; Hart, S.; He, Y.; Heros, C.P. de los; Hill, G.; Hulth, P.O.; Hundertmark, S.; Jacobsen, J.; Jones, A.; Kandhadai, V.; Karle, A.; Kim, J.; Leich, H.; Leuthold, M.; Lindahl, P.; Liubarsky, I.; Loaiza, P.; Lowder, D.; Marciniewski, P.; Miller, T.C.; Miocinovic, P.; Mock, P.C.; Morse, R.; Newcomer, M.; Niessen, P.; Nygren, D.; Porrata, R.; Potter, D.; Price, P.B.; Przybylski, G.; Rhode, W.; Richter, S.; Rodriquez, J.; Romenesko, P.; Ross, D.; Rubinstein, H.; Schmidt, T.; Schneider, E.; Schwartz, R.; Schwendicke, U.; Smoot, G.; Solarz, M.; Sorin, V.; Spiering, C.; Steffen, P.; Stokstad, R.; Streicher, O.; Taboada, I.; Thon, T.; Tilav, S.; Walck, C.; Wiebusch, C.H.; Wischnewski, R.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S

    1999-05-01

    With an effective telescope area of order 10{sup 4} m{sup 2} for TeV neutrinos, a threshold near {approx}50 GeV and a pointing accuracy of 2.5 degrees per muon track, the AMANDA detector represents the first of a new generation of high energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We describe early results on the calibration of natural deep ice as a particle detector as well as on AMANDA's performance as a neutrino telescope.

  17. Modular assembled space telescope

    Science.gov (United States)

    Feinberg, Lee D.; Budinoff, Jason; MacEwen, Howard; Matthews, Gary; Postman, Marc

    2013-09-01

    We present a new approach to building a modular segmented space telescope that greatly leverages the heritage of the Hubble Space Telescope and the James Webb Space Telescope. The modular design in which mirror segments are assembled into identical panels allows for economies of scale and for efficient space assembly that make a 20-m aperture approach cost effective. This assembly approach can leverage NASA's future capabilities and has the power to excite the public's imagination. We discuss the science drivers, basic architecture, technology, and leveraged NASA infrastructure, concluding with a proposed plan for going forward.

  18. VLT-MAD observations of the core of 30 Doradus

    CERN Document Server

    Campbell, M A; Mackey, A D; Gieles, M; Alves, J; Ascenso, J; Bastian, N; Longmore, A J

    2010-01-01

    We present H- and Ks-band imaging of three fields at the centre of 30 Doradus in the Large Magellanic Cloud, obtained as part of the Science Demonstration programme with the Multi-conjugate Adaptive optics Demonstrator (MAD) at the Very Large Telescope. Strehl ratios of 15-30% were achieved in the Ks-band, yielding near-infrared images of this dense and complex region at unprecedented angular resolution at these wavelengths. The MAD data are used to construct a near-infrared luminosity profile for R136, the cluster at the core of 30 Dor. Using cluster profiles of the form used by Elson et al., we find the surface brightness can be fit by a relatively shallow power-law function (gamma~1.5-1.7) over the full extent of the MAD data, which extends to a radius of ~40" (~10pc). We do not see compelling evidence for a break in the luminosity profile as seen in optical data in the literature, arguing that cluster asymmetries are the dominant source, although extinction effects and stars from nearby triggered star-for...

  19. Goddard Robotic Telescope (GRT)

    Data.gov (United States)

    National Aeronautics and Space Administration — Since it is not possible to predict when a Gamma-Ray Burst (GRB) occurs, the follow-up ground telescopes must be distributed as uniform as possible all over the...

  20. Parabolic Strip Telescope

    CERN Document Server

    Chadzitaskos, Goce

    2013-01-01

    We present a proposal of a new type of telescopes using a rotating parabolic strip as the primary mirror. It is the most principal modification of the design of telescopes from the times of Galileo and Newton. In order to demonstrate the basic idea, the image of an artificial constellation observed by this kind of telescope was reconstructed using the techniques described in this article. As a working model of this new telescope, we have used an assembly of the primary mirror---a strip of acrylic glass parabolic mirror 40 cm long and 10 cm wid shaped as a parabolic cylinder of focal length 1 m---and an artificial constellation, a set of 5 apertures in a distance of 5 m illuminated from behind. In order to reconstruct the image, we made a series of snaps, each after a rotation of the constellation by 15 degrees. Using Matlab we reconstructed the image of the artificial constellation.

  1. The Dark Matter Telescope

    CERN Document Server

    Tyson, J A; Angel, J R P; Wittman, David

    2001-01-01

    Weak gravitational lensing enables direct reconstruction of dark matter maps over cosmologically significant volumes. This research is currently telescope-limited. The Dark Matter Telescope (DMT) is a proposed 8.4 m telescope with a 3 degree field of view, with an etendue of 260 $(m. degree)^2$, ten times greater than any other current or planned telescope. With its large etendue and dedicated observational mode, the DMT fills a nearly unexplored region of parameter space and enables projects that would take decades on current facilities. The DMT will be able to reach 10-sigma limiting magnitudes of 27-28 magnitude in the wavelength range .3 - 1 um over a 7 square degree field in 3 nights of dark time. Here we review its unique weak lensing cosmology capabilities and the design that enables those capabilities.

  2. Large Binocular Telescope Project

    Science.gov (United States)

    Hill, John M.

    1997-03-01

    The large binocular telescope (LBT) project have evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 by 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astrofisico di Arcetri and the Research Corporation based in Tucson, Arizona. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train -- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in the fall of 1996 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximum flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximum stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1996 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson), EIE and ADS Italia

  3. Chemical abundances in the protoplanetary disc LV 2 (Orion) - II. High-dispersion VLT observations and microjet properties

    Science.gov (United States)

    Tsamis, Y. G.; Walsh, J. R.

    2011-11-01

    Integral field spectroscopy of the LV 2 proplyd is presented taken with the Very Large Telescope (VLT)/FLAMES Argus array at an angular resolution of 0.31 × 0.31 arcsec2 and velocity resolutions down to 2 km s-1 pixel-1. Following subtraction of the local M42 emission, the spectrum of LV 2 is isolated from the surrounding nebula. We measured the heliocentric velocities and widths of a number of lines detected in the intrinsic spectrum of the proplyd, as well as in the adjacent Orion nebula falling within a 6.6 × 4.2 arcsec2 field of view. It is found that far-ultraviolet to optical collisional lines with critical densities, Ncr, ranging from 103 to 109 cm-3 suffer collisional de-excitation near the rest velocity of the proplyd correlating tightly with their critical densities. Lines of low Ncr are suppressed the most. The bipolar jet arising from LV 2 is spectrally and spatially well detected in several emission lines. We compute the [O III] electron temperature profile across LV 2 in velocity space and measure steep temperature variations associated with the red-shifted lobe of the jet, possibly being due to a shock discontinuity. From the velocity-resolved analysis the ionized gas near the rest frame of LV 2 has Te= 9200 ± 800 K and Ne˜ 106 cm-3, while the red-shifted jet lobe has Te≈ 9000-104 K and Ne˜ 106-107 cm-3. The jet flow is highly ionized but contains dense semineutral clumps emitting neutral oxygen lines. The abundances of N+, O2 +, Ne2 +, Fe2 +, S+and S2 +are measured for the strong red-shifted jet lobe. Iron in the core of LV 2 is depleted by 2.54 dex with respect to solar as a result of sedimentation on dust, whereas the efficient destruction of dust grains in the fast microjet raises its Fe abundance to at least 30 per cent solar. Sulphur does not show evidence of significant depletion on dust, but its abundance both in the core and the jet is only about half solar. Based on observations made with ESO telescopes at the Paranal Observatory

  4. Estimating phase errors from pupil discontinuities from simulated on sky data: examples with VLT and Keck

    Science.gov (United States)

    Lamb, Masen; Correia, Carlos; Sauvage, Jean-François; Véran, Jean-Pierre; Andersen, David; Vigan, Arthur; Wizinowich, Peter; van Dam, Marcos; Mugnier, Laurent; Bond, Charlotte

    2016-07-01

    We propose and apply two methods for estimating phase discontinuities for two realistic scenarios on VLT and Keck. The methods use both phase diversity and a form of image sharpening. For the case of VLT, we simulate the `low wind effect' (LWE) which is responsible for focal plane errors in low wind and good seeing conditions. We successfully estimate the LWE using both methods, and show that using both methods both independently and together yields promising results. We also show the use of single image phase diversity in the LWE estimation, and show that it too yields promising results. Finally, we simulate segmented piston effects on Keck/NIRC2 images and successfully recover the induced phase errors using single image phase diversity. We also show that on Keck we can estimate both the segmented piston errors and any Zernike modes affiliated with the non-common path.

  5. CLASH-VLT: A highly precise strong lensing model of the galaxy cluster RXC J2248.7-4431 (Abell S1063) and prospects for cosmography

    Science.gov (United States)

    Caminha, G. B.; Grillo, C.; Rosati, P.; Balestra, I.; Karman, W.; Lombardi, M.; Mercurio, A.; Nonino, M.; Tozzi, P.; Zitrin, A.; Biviano, A.; Girardi, M.; Koekemoer, A. M.; Melchior, P.; Meneghetti, M.; Munari, E.; Suyu, S. H.; Umetsu, K.; Annunziatella, M.; Borgani, S.; Broadhurst, T.; Caputi, K. I.; Coe, D.; Delgado-Correal, C.; Ettori, S.; Fritz, A.; Frye, B.; Gobat, R.; Maier, C.; Monna, A.; Postman, M.; Sartoris, B.; Seitz, S.; Vanzella, E.; Ziegler, B.

    2016-03-01

    Aims: We perform a comprehensive study of the total mass distribution of the galaxy cluster RXC J2248.7-4431 (z = 0.348) with a set of high-precision strong lensing models, which take advantage of extensive spectroscopic information on many multiply lensed systems. In the effort to understand and quantify inherent systematics in parametric strong lensing modelling, we explore a collection of 22 models in which we use different samples of multiple image families, different parametrizations of the mass distribution and cosmological parameters. Methods: As input information for the strong lensing models, we use the Cluster Lensing And Supernova survey with Hubble (CLASH) imaging data and spectroscopic follow-up observations, with the VIsible Multi-Object Spectrograph (VIMOS) and Multi Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT), to identify and characterize bona fide multiple image families and measure their redshifts down to mF814W ≃ 26. A total of 16 background sources, over the redshift range 1.0-6.1, are multiply lensed into 47 images, 24 of which are spectroscopically confirmed and belong to ten individual sources. These also include a multiply lensed Lyman-α blob at z = 3.118. The cluster total mass distribution and underlying cosmology in the models are optimized by matching the observed positions of the multiple images on the lens plane. Bayesian Markov chain Monte Carlo techniques are used to quantify errors and covariances of the best-fit parameters. Results: We show that with a careful selection of a large sample of spectroscopically confirmed multiple images, the best-fit model can reproduce their observed positions with a rms scatter of 0.̋3 in a fixed flat ΛCDM cosmology, whereas the lack of spectroscopic information or the use of inaccurate photometric redshifts can lead to biases in the values of the model parameters. We find that the best-fit parametrization for the cluster total mass distribution is composed of an

  6. The Multiple-Mirror Telescope

    Science.gov (United States)

    Carleton, Nathaniel P.; Hoffmann, William F.

    1978-01-01

    Describes the basic design and principle of operating an optical-infrared telescope, the MMT. This third largest telescope in the world represents a new stage in telescope design; it uses a cluster of six reflecting telescopes, and relies on an automatic sensing and control system. (GA)

  7. Effects of a Video Lottery Terminal (VLT) Banner on Gambling: A Field Study

    Science.gov (United States)

    Gallagher, Timothy; Nicki, Richard; Otteson, Amy; Elliott, Heather

    2011-01-01

    The effects of a warning banner, informing patrons of the randomness of Video Lottery Terminal (VLT) outcomes, on gambling behaviour and beliefs were tested in a field setting using a mixed-model 2 x 3 design over a six-week period with 27 problem and 27 non-problem gamblers recruited from bars in a Canadian city with a population of 85,000.…

  8. Velocity fields of distant galaxies with FORS2 at the VLT

    CERN Document Server

    Ziegler, Bodo L; Da Rocha, Cristiano; Böhm, Asmus; Kapferer, Wolfgang; Kuntschner, Harald; Peletier, Reynier F; Schindler, Sabine; Verdugo, Miguel

    2009-01-01

    We describe a method to efficiently obtain two-dimensional velocity fields of distant, faint and small, emission-line galaxies with FORS2 at the VLT. They are examined for kinematic substructure to identify possible interaction processes. Numerical simulations of tidal interactions and ram-pressure effects reveal distinct signatures observable with our method. We detect a significant fraction of galaxies with irregular velocity fields both in the field and cluster environments.

  9. CRIRES+ : A Cross-dispersed High-resolution Infrared Spectrograph for ESO's VLT

    Science.gov (United States)

    Hatzes, Artie; CRIRES+ Team

    2017-06-01

    CRIRES+ is a major upgrade to the former CRyogenic high resolution Infra-Red Echelle Spectrograph of ESO's 8.2m Very Large Telescope. The major science drivers for this upgrade are the confirmation and characterization (e.g. determination of the mass) of rocky planets in the so-called habitable zone of M-dwarf stars via radial velocity measurements, the characterization of exoplanet atmospheres, and the study of magnetic fields in low mass stars and brown dwarfs. CRIRES+ will maintain the high resolving power (R = 100,000) of its predecessor in the Y, J, H, K, L and M bands, but it will include the following improvements: 1) CRIRES+ will be cross-dispersed recording 8-9 diffraction orders at a time, increasing the observing efficiency approximately by an order of magnitude. 2) New detectors with better sensitivity and cosmetics over the old devices. 3) A new gas absorption cell for improved wavelength calibration. This along with the increased wavelength coverage should yield a radial velocity measurement precision to better than 2-5 m/s in K-band. In addition, in Y to K bands, a new Fabry-Perot etalon device will ensure a precision of 100 m/s. 4) A polarimetric unit which will measure both circular and linear polarization. We present the current status and schedule of the project. The instrument is currently scheduled to be installed at the telescope beginning 2018.

  10. A valiant little terminal: A VLT user`s manual. Revision 4

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, A.

    1992-08-01

    VLT came to be used at SLAC (Stanford Linear Accelerator Center), because SLAC wanted to assess the Amiga`s usefulness as a color graphics terminal and T{sub E}X workstation. Before the project could really begin, the people at SLAC needed a terminal emulator which could successfully talk to the IBM 3081 (now the IBM ES9000-580) and all the VAXes on the site. Moreover, it had to compete in quality with the Ann Arbor Ambassador GXL terminals which were already in use at the laboratory. Unfortunately, at the time there was no commercial program which fit the bill. Luckily, Willy Langeveld had been independently hacking up a public domain VT100 emulator written by Dave Wecker et al. and the result, VLT, suited SLAC`s purpose. Over the years, as the program was debugged and rewritten, the original code disappeared, so that now, in the present version of VLT, none of the original VT100 code remains.

  11. A valiant little terminal: A VLT user's manual

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, A.

    1992-08-01

    VLT came to be used at SLAC (Stanford Linear Accelerator Center), because SLAC wanted to assess the Amiga's usefulness as a color graphics terminal and T{sub E}X workstation. Before the project could really begin, the people at SLAC needed a terminal emulator which could successfully talk to the IBM 3081 (now the IBM ES9000-580) and all the VAXes on the site. Moreover, it had to compete in quality with the Ann Arbor Ambassador GXL terminals which were already in use at the laboratory. Unfortunately, at the time there was no commercial program which fit the bill. Luckily, Willy Langeveld had been independently hacking up a public domain VT100 emulator written by Dave Wecker et al. and the result, VLT, suited SLAC's purpose. Over the years, as the program was debugged and rewritten, the original code disappeared, so that now, in the present version of VLT, none of the original VT100 code remains.

  12. Lyman-\\alpha{} Emitters in the context of hierarchical galaxy formation: predictions for VLT/MUSE surveys

    CERN Document Server

    Garel, Thibault; Blaizot, Jérémy

    2015-01-01

    The VLT Multi Unit Spectroscopic Explorer (MUSE) integral-field spectrograph can detect Ly\\alpha{} emitters (LAE) in the redshift range $2.8 \\lesssim z \\lesssim 6.7$ in a homogeneous way. Ongoing MUSE surveys will notably probe faint Ly\\alpha{} sources that are usually missed by current narrow-band surveys. We provide quantitative predictions for a typical wedding-cake observing strategy with MUSE based on mock catalogs generated with a semi-analytic model of galaxy formation coupled to numerical Ly\\alpha{} radiation transfer models in gas outflows. We expect $\\approx$ 1500 bright LAEs ($F_{Ly\\alpha}$ $\\gtrsim$ $10^{-17}$ erg s$^{-1}$ cm$^{-2}$) in a typical Shallow Field (SF) survey carried over $\\approx$ 100 arcmin$^2$, and $\\approx$ 2,000 sources as faint as $10^{-18}$ erg s$^{-1}$ cm$^{-2}$ in a Medium-Deep Field (MDF) survey over 10 arcmin$^2$. In a typical Deep Field (DF) survey of 1 arcmin$^2$, we predict that $\\approx$ 500 extremely faint LAEs ($F_{Ly\\alpha}$ $\\gtrsim$ $4 \\times 10^{-19}$ erg s$^{-1}$...

  13. Development of the Ball integrated telescope model (ITM)

    Science.gov (United States)

    Lieber, Michael D.

    2002-07-01

    As the complexity of telescope systems have increased, system engineering trades related to cost and performance issues have become correspondingly complex. The traditional methodology for end-to-end system modeling depends upon focused analysis and data handoff between disciplines - aptly termed the "bucket brigade" approach. For the last 7 years, Ball Aerospace has supported development of an integrated modeling environment for telescope performance modeling and analysis. The Integrated Telescope Model (ITM), a realization of this effort, has been used on several current large telescope programs such as the VLT, NGST, TPF and MAXIM. It permits the user to do both time simulations and analytical work in the spatial/temporal frequency domains. The individual discipline models in structural dynamics, optics, controls, signal processing, detector physics and disturbance modeling are seamlessly integrated into one cohesive model to efficiently support system level trades and analysis. The core of the model is formed by the optical toolbox implemented in MATLAB and realized in object-oriented Simulink environment. Both geometric and physical optical models can be constructed and interfaced to disturbances and detection models. The geometric approach includes ray tracing for exact modeling or sensitivity matrices for rapid execution. Spectral, transmission and polarization information is carried with each ray. The physical optics modules do wavefront propagation for analyzing diffraction effects under either with coherent or incoherent conditions. Coupling of the static offset models, quasi-static thermal deformations and structural dynamics with an optical model allows one to view the full range of disturbance effects on the resulting PSF. This paper addresses the overall model architecture, considerations and issues related to model execution speed, complexity and model resolution/validity. Example of a recent use of the model is reviewed.

  14. Direct Imaging of Exoplanets, from very large to extremely large telescopes

    Science.gov (United States)

    Kasper, M.

    2015-10-01

    Presently, dedicated instruments at 8-m class telescopes (SPHERE for the VLT, GPI for Gemini) are about to discover and explore self-luminous giant planets by direct imaging and spectroscopy. In a decade, the next generation of 30m-40m ground-based Extremely Large Telescopes (ELTs) have the potential to dramatically enlarge the discovery space towards older giant planets seen in the reflected light and ultimately even a small number of rocky planets. In order to fulfill the demanding contrast requirements of a part in a million to a part in a billion at separations of one tenth of an arcsecond, the seeing limited PSF contrast must gradually be improved by eXtreme Adaptive optics (XAO), non-common path aberration compensation, coronagraphy, and science image post-processing. None of these steps alone is sufficient to leap the enormous contrast. High-contrast imaging (HCI) from the ground encompasses all those disciplines which are to be considered in a system approach. The presentation will introduce the principle of HCI and present the current implementation in the SPHERE, ESO's imager for giant exoplanets at the VLT. It will then discuss requirements and necessary R&D to reach the ultimate goal, observing terrestrial Exoplanets with the next generation of instruments for the ELTs.

  15. Robotic and Survey Telescopes

    Science.gov (United States)

    Woźniak, Przemysław

    Robotic telescopes are revolutionizing the way astronomers collect their dataand conduct sky surveys. This chapter begins with a discussion of principles thatguide the process of designing, constructing, and operating telescopes andobservatories that offer a varying degree of automation, from instruments remotelycontrolled by observers to fully autonomous systems requiring no humansupervision during their normal operations. Emphasis is placed on designtrade-offs involved in building end-to-end systems intended for a wide range ofscience applications. The second part of the chapter contains descriptions ofseveral projects and instruments, both existing and currently under development.It is an attempt to provide a representative selection of actual systems thatillustrates state of the art in technology, as well as important ideas and milestonesin the development of the field. The list of presented instruments spans the fullrange in size starting from small all-sky monitors, through midrange robotic andsurvey telescopes, and finishing with large robotic instruments and surveys.Explosive growth of telescope networking is enabling entirely new modesof interaction between the survey and follow-up observing. Increasingimportance of standardized communication protocols and software is stressed.These developments are driven by the fusion of robotic telescope hardware,massive storage and databases, real-time knowledge extraction, and datacross-correlation on a global scale. The chapter concludes with examplesof major science results enabled by these new technologies and futureprospects.

  16. The South Pole Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Ruhl, J.E.; Ade, P.A.R.; Carlstrom, J.E.; Cho, H.M.; Crawford,T.; Dobbs, M.; Greer, C.H.; Halverson, N.W.; Holzapfel, W.L.; Lanting,T.M.; Lee, A.T.; Leitch, E.M.; Leong, J.; Lu, W.; Lueker, M.; Mehl, J.; Meyer, S.S.; Mohr, J.J.; Padin, S.; Plagge, T.; Pryke, C.; Runyan, M.C.; Schwan, D.; Sharp, M.K.; Spieler, H.; Staniszewski, Z.; Stark, A.A.

    2004-11-04

    A new 10 meter diameter telescope is being constructed for deployment at the NSF South Pole research station. The telescope is designed for conducting large-area millimeter and sub-millimeter wave surveys of faint, low contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background. To achieve the required sensitivity and resolution, the telescope design employs an off-axis primary with a 10 m diameter clear aperture. The full aperture and the associated optics will have a combined surface accuracy of better than 20 microns rms to allow precision operation in the submillimeter atmospheric windows. The telescope will be surrounded with a large reflecting ground screen to reduce sensitivity to thermal emission from the ground and local interference. The optics of the telescope will support a square degree field of view at 2mm wavelength and will feed a new 1000-element micro-lithographed planar bolometric array with superconducting transition-edge sensors and frequency-multiplexed readouts. The first key project will be to conduct a survey over 4000 degrees for galaxy clusters using the Sunyaev-Zeldovich Effect. This survey should find many thousands of clusters with a mass selection criteria that is remarkably uniform with redshift. Armed with redshifts obtained from optical and infrared follow-up observations, it is expected that the survey will enable significant constraints to be placed on the equation of state of the dark energy.

  17. The Travelling Telescope

    Science.gov (United States)

    Murabona Oduori, Susan

    2015-08-01

    The telescope has been around for more than 400 years, and through good use of it scientists have made many astonishing discoveries and begun to understand our place in the universe. Most people, however, have never looked through one. Yet it is a great tool for cool science and observation especially in a continent and country with beautifully dark skies. The Travelling Telescope project aims to invite people outside under the stars to learn about those curious lights in the sky.The Travelling Telescope aims to promote science learning to a wide range of Kenyan schools in various locations exchanging knowledge about the sky through direct observations of celestial bodies using state of the art telescopes. In addition to direct observing we also teach science using various hands-on activities and astronomy software, ideal for explaining concepts which are hard to understand, and for a better grasp of the sights visible through the telescope. We are dedicated to promoting science using astronomy especially in schools, targeting children from as young as 3 years to the youth, teachers, their parents and members of the public. Our presentation focuses on the OAD funded project in rural coastal Kenya.

  18. The South Pole Telescope

    CERN Document Server

    Ruhl, J E; Carlstrom, J E; Cho, H M; Crawford, T; Dobbs, M; Greer, C H; Halverson, W; Holzapfel, W L; Lanting, T M; Lee, A T; Leong, J; Leitch, E M; Lu, W; Lueker, M; Mehl, J; Meyer, S S; Mohr, J J; Padin, S; Plagge, T; Pryke, C L; Schwan, D; Sharp, M K; Runyan, M C; Spieler, H; Staniszewski, Z; Stark, A A

    2004-01-01

    A new 10 meter diameter telescope is being constructed for deployment at the NSF South Pole research station. The telescope is designed for conducting large-area millimeter and sub-millimeter wave surveys of faint, low contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background. To achieve the required sensitivity and resolution, the telescope design employs an off-axis primary with a 10m diameter clear aperture. The full aperture and the associated optics will have a combined surface accuracy of better than 20 microns rms to allow precision operation in the submillimeter atmospheric windows. The telescope will be surrounded with a large reflecting ground screen to reduce sensitivity to thermal emission from the ground and local interference. The optics of the telescope will support a square degree field of view at 2mm wavelength and will feed a new 1000-element micro-lithographed planar bolometric array with superconducting transition-edge sensors and frequency...

  19. Rapid-response mode VLT/UVES spectroscopy of super iron-rich gas exposed to GRB 080310. Evidence of ionization in action and episodic star formation in the host

    CERN Document Server

    De Cia, A; Fox, A J; Vreeswijk, P M; Smette, A; Petitjean, P; Bjornsson, G; Fynbo, J P U; Hjorth, J; Jakobsson, P

    2012-01-01

    We analyse high-resolution near-UV and optical spectra of the afterglow of GRB 080310, obtained with the Very Large Telescope Ultraviolet and Visual Echelle Spectrograph (VLT/UVES), to investigate the circumburst environment and the interstellar medium of the gamma-ray burst (GRB) host galaxy. The VLT rapid-response mode (RRM) enabled the observations to start only 13 minutes after the Swift trigger and a series of four exposures to be collected before dawn. A low neutral-hydrogen column-density (log N (HI) = 18.7) is measured at the host-galaxy redshift of z = 2.42743. At this redshift, we also detect a large number of resonance ground-state absorption lines (e.g., CII, MgII, AlII, SiII, CrII, CIV, SiIV), as well as time-varying absorption from the fine-structure levels of FeII. Time-varying absorption from a highly excited FeIII energy level (7S3), giving rise to the so-called UV34 line triplet, is also detected, for the first time in a GRB afterglow. The CrII ground-state and all observed FeII energy level...

  20. LSST telescope modeling overview

    Science.gov (United States)

    Sebag, J.; Andrew, J.; Angeli, G.; Araujo, C.; Barr, J.; Callahan, S.; Cho, M.; Claver, C.; Daruich, F.; Gressler, W.; Hileman, E.; Liang, M.; Muller, G.; Neill, D.; Schoening, W.; Warner, M.; Wiecha, O.; Xin, B.; Orden Martinez, Alfredo; Perezagua Aguado, Manuel; García Marchena, Luis; Ruiz de Argandoña, Ismael

    2016-08-01

    During this early stage of construction of the Large Synoptic Survey Telescope (LSST), modeling has become a crucial system engineering process to ensure that the final detailed design of all the sub-systems that compose the telescope meet requirements and interfaces. Modeling includes multiple tools and types of analyses that are performed to address specific technical issues. Three-dimensional (3D) Computeraided Design (CAD) modeling has become central for controlling interfaces between subsystems and identifying potential interferences. The LSST Telescope dynamic requirements are challenging because of the nature of the LSST survey which requires a high cadence of rapid slews and short settling times. The combination of finite element methods (FEM), coupled with control system dynamic analysis, provides a method to validate these specifications. An overview of these modeling activities is reported in this paper including specific cases that illustrate its impact.

  1. Telescopes and Techniques

    CERN Document Server

    Kitchin, C R

    2013-01-01

    Telescopes and Techniques has proved itself in its first two editions, having become probably one of the most widely used astronomy texts, both for amateur astronomers and astronomy and astrophysics undergraduates. Both earlier editions of the book were widely used for introductory practical astronomy courses in many universities. In this Third Edition the author guides the reader through the mathematics, physics and practical techniques needed to use today's telescopes (from the smaller models to the larger instruments installed in many colleges) and how to find objects in the sky. Most of the physics and engineering involved is described fully and requires little prior knowledge or experience. Both visual and electronic imaging techniques are covered, together with an introduction to how data (measurements) should be processed and analyzed. A simple introduction to radio telescopes is also included. Brief coverage of the more advanced topics of photometry and spectroscopy are included, but mainly to enable ...

  2. Integrated Modeling of Telescopes

    CERN Document Server

    Andersen, Torben

    2011-01-01

    With increasingly complex and costly opto-mechanical systems, there is a growing need for reliable computer modeling and simulation. The field of integrated modeling, combining optics, mechanics, control engineering, and other disciplines, is the subject of this book. Although the book primarily focuses on ground-based optical telescopes, the techniques introduced are applicable also to other wavelengths and to other opto-mechanical applications on the ground or in space. Basic tools of integrated modeling are introduced together with concepts of ground-based telescopes. Modeling of optical systems, structures, wavefront control systems with emphasis on segmented mirror control, and active and adaptive optics are described together with a variety of noise sources; many examples are included in this book. Integrated Modeling of Telescopes is a text for physicists and engineers working in the field of opto-mechanical design and wavefront control, but it will also be valuable as a textbook for PhD students.

  3. The Discovery Channel Telescope

    Science.gov (United States)

    Millis, R. L.; Dunham, E. W.; Sebring, T. A.; Smith, B. W.; de Kock, M.; Wiecha, O.

    2004-11-01

    The Discovery Channel Telescope (DCT) is a 4.2-m telescope to be built at a new site near Happy Jack, Arizona. The DCT features a large prime focus mosaic CCD camera with a 2-degree-diameter field of view especially designed for surveys of KBOs, Centaurs, NEAs and other moving or time-variable targets. The telescope can be switched quickly to a Ritchey-Chretien configuration for optical/IR spectroscopy or near-IR imaging. This flexibility allows timely follow-up physical studies of high priority objects discovered in survey mode. The ULE (ultra-low-expansion) meniscus primary and secondary mirror blanks for the telescope are currently in fabrication by Corning Glass. Goodrich Aerospace, Vertex RSI, M3 Engineering and Technology Corp., and e2v Technologies have recently completed in-depth conceptual design studies of the optics, mount, enclosure, and mosaic focal plane, respectively. The results of these studies were subjected to a formal design review in July, 2004. Site testing at the 7760-ft altitude Happy Jack site began in 2001. Differential image motion observations from 117 nights since January 1, 2003 gave median seeing of 0.84 arcsec FWHM, and the average of the first quartile was 0.62 arcsec. The National Environmental Policy Act (NEPA) process for securing long-term access to this site on the Coconino National Forest is nearing completion and ground breaking is expected in the spring of 2005. The Discovery Channel Telescope is a project of the Lowell Observatory with major financial support from Discovery Communications, Inc. (DCI). DCI plans ongoing television programming featuring the construction of the telescope and the research ultimately undertaken with the DCT. An additional partner can be accommodated in the project. Interested parties should contact the lead author.

  4. Pointing the SOFIA Telescope

    CERN Document Server

    Gross, Michael A K; Moore, Elizabeth M

    2010-01-01

    SOFIA is an airborne, gyroscopically stabilized 2.5m infrared telescope, mounted to a spherical bearing. Unlike its predecessors, SOFIA will work in absolute coordinates, despite its continually changing position and attitude. In order to manage this, SOFIA must relate equatorial and telescope coordinates using a combination of avionics data and star identification, manage field rotation and track sky images. We describe the algorithms and systems required to acquire and maintain the equatorial reference frame, relate it to tracking imagers and the science instrument, set up the oscillating secondary mirror, and aggregate pointings into relocatable nods and dithers.

  5. Reflecting telescope optics

    CERN Document Server

    Wilson, Raymond N

    2004-01-01

    R.N. Wilson's two-volume treatise on reflecting telescope optics has become a classic in its own right. It is intended to give a complete treatment of the subject, addressing professionals in research and industry as well as students of astronomy and amateur astronomers. This first volume, Basic Design Theory and its Historical Development, is devoted to the theory of reflecting telescope optics and systematically recounts the historical progress. The author's approach is morphological, with strong emphasis on the historical development. The book is richly illustrated including spot-diagrams a

  6. New Vacuum Solar Telescope

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With its pure aperture up to 985mm, the New Vacuum Solar Telescope of China (NVST) has become the world's biggest vacuum solar telescope. The main science task of NVST is the high-resolution observation of photosphere and chromosphere including their fine structure of magnetic field on the sun. The NVST was equipped with many new technologies and powerful instruments, such as an adaptive optical system, a polarization analyzer, two vertical spectrographs, a high-resolution image system and a very narrow Ha filter (0.125A).

  7. The Cepheid distance to NGC 5236 (M83) with the ESO Very Large Telescope

    NARCIS (Netherlands)

    Thim, F; Tammann, GA; Saha, A; Dolphin, A; Sandage, A; Tolstoy, E; Labhardt, L

    2003-01-01

    Cepheids have been observed in NGC 5236 (M83) using the Antu (Unit Telescope 1) 8.2 m telescope of the ESO Very Large Telescope with the Focal Reducer/Low Dispersion Spectrograph 1. Repeated imaging observations have been made between 2000 January and 2001 July. Images were obtained in 34 epochs in

  8. MROI Array telescopes: the relocatable enclosure domes

    Science.gov (United States)

    Marchiori, G.; Busatta, A.; Payne, I.

    2016-07-01

    The MROI - Magdalena Ridge Interferometer is a project which comprises an array of up to 10 1.4m diameter mirror telescopes arranged in a "Y" configuration. Each of these telescopes will be housed inside a Unit Telescope Enclosure (UTE) which are relocatable onto any of 28 stations. EIE GROUP Srl, Venice - Italy, was awarded the contract for the design, the construction and the erection on site of the MROI by the New Mexico Institute of Mining and Technology. The close-pack array of the MROI - including all 10 telescopes, several of which are at a relative distance of less than 8m center to center from each other - necessitated an original design for the Unit Telescope Enclosure (UTE). This innovative design enclosure incorporates a unique dome/observing aperture system to be able to operate in the harsh environmental conditions encountered at an altitude of 10,460ft (3,188m). The main characteristics of this Relocatable Enclosure Dome are: a Light insulated Steel Structure with a dome made of composites materials (e.g. glass/carbon fibers, sandwich panels etc.), an aperture motorized system for observation, a series of louvers for ventilation, a series of electrical and plants installations and relevant auxiliary equipment. The first Enclosure Dome is now under construction and the completion of the mounting on site id envisaged by the end of 2016. The relocation system utilizes a modified reachstacker (a transporter used to handle freight containers) capable of maneuvering between and around the enclosures, capable of lifting the combined weight of the enclosure with the telescope (30tons), with minimal impacts due to vibrations.

  9. Funding for Adaptive Optics in the United States by the National Science Foundation 2006-2009: An Update

    CERN Document Server

    Frogel, Jay A

    2009-01-01

    In 2006 I published an article in GeminiFocus that examined funding for astronomical adaptive optics related technology and instrumentation in the United States from 1995 through mid-2006. That article concluded that based on projections then current, AO implementation on public and private telescopes in the U.S. will soon seriously lag that on the ESO VLT as measured by funds available. It called for a significant infusion of public funds for AO development and implementation so that when combined with private funds, the U.S. astronomical community as a whole would be able to take full advantage of AO systems on both public and private telescopes. In 2006 I estimated that the total amount of public (NSF) funds that would be available in 2009 for AO related non-science activities would be about $6M. This article updates the analysis done in my previous article. I show that for 2009 the funds for AO related non-science activities are about $7M in spite of the termination of the AODP program. Federal stimulus f...

  10. THE LARGE MILLIMETER TELESCOPE

    Directory of Open Access Journals (Sweden)

    D. H. Hughes

    2009-01-01

    Full Text Available This paper, presented on behalf of the Large Millimeter Telescope (LMT project team, describes the status and near-term plans for the telescope and its initial instrumentation. The LMT is a bi-national collaboration between M xico and the USA, led by the Instituto Nacional de Astrof sica, ptica y Electr nica (INAOE and the University of Massachusetts at Amherst, to construct, commission and operate a 50 m diameter millimeterwave radio telescope. Construction activities are nearly complete at the LMT site, at an altitude of 4600 m on the summit of Sierra Negra, an extinct volcano in the Mexican state of Puebla. Full movement of the telescope, under computer control in both azimuth and elevation, has been achieved. First-light at centimeter wavelengths on astronomical sources was obtained in November 2006. Installation of precision surface segments for millimeter-wave operation is underway, with the inner 32 m diameter of the surface now complete and ready to be used to obtain rst-light at millimeter wavelengths in 2008. Installation of the remainder of the re ector will continue during the next year and be completed in 2009 for nal commissioning of the antenna. The full LMT antenna, out ted with its initial complement of scienti c instruments, will be a world-leading scienti c research facility for millimeter-wave astronomy.

  11. A Simple "Tubeless" Telescope

    Science.gov (United States)

    Straulino, S.; Bonechi, L.

    2010-01-01

    Two lenses make it possible to create a simple telescope with quite large magnification. The set-up is very simple and can be reproduced in schools, provided the laboratory has a range of lenses with different focal lengths. In this article, the authors adopt the Keplerian configuration, which is composed of two converging lenses. This instrument,…

  12. Exploring Galileo's Telescope

    Science.gov (United States)

    Straulino, Samuele; Terzuoli, Alessandra

    2010-01-01

    In the first months of 2009, the International Year of Astronomy, the authors developed an educational project for middle-level students connected with the first astronomical discoveries that Galileo Galilei (1564-1642) made 400 years ago. The project included the construction of a basic telescope and the observation of the Moon. The project, if…

  13. pVLT-EGFP载体构建及其在巴西固氮螺菌(Azospirillum brasilense)的表达研究%Construction of an Expression Vector pVLT-EGFP and Its Expression in Azospirillum brasilense

    Institute of Scientific and Technical Information of China (English)

    巩涛; 王继雯; 杨文玲; 甄静; 刘莹莹; 李冠杰; 刘莉; 岳丹丹; 陈国参

    2015-01-01

    为了研究巴西固氮螺菌(Azospirillum brasilense)在植物体内的定殖,利用酶切连接的方法,以增强型绿色荧光蛋白(enhanced green fluorescent protein,EGFP)基因与表达栽体pVLT-33为基本元件,构建了重组表达载体pVLT-EGFP,电转巴西固氮螺菌R7细胞,并利用实时荧光定量PCR(qPCR)研究了不同温度、不同时间EGFP mRNA的表达情况.酶切及测序结果表明,成功构建了pVLT-EGFP载体,并在荧光显微镜下观察到绿色荧光蛋白表达;qPCR结果显示:30℃,诱导9hEGFP基因的表达水平最高.本研究成功构建了重组表达载体pVLT-EGFP,为实现pVLT-EGFP的可控表达及研究固氮菌在植物体内的定殖规律及促生长机理提供了一种有效的途径.

  14. Observing multiple stellar populations with FORS2@VLT - Main sequence photometry in outer regions of NGC 6752, NGC 6397, and NGC 6121 (M 4)

    CERN Document Server

    Nardiello, D; Piotto, G; Marino, A F; Bellini, A; Cassisi, S

    2014-01-01

    We present the photometric analysis of the external regions of three Galactic Globular Clusters: NGC 6121, NGC 6397 and NGC 6752. The main goal is the characterization of the multiple stellar populations along the main sequence (MS) and the study of the radial trend of the different populations hosted by the target clusters. The data have been collected using FORS2 mounted at the ESO/VLT@UT1 telescope in UBVI filters. From these data sets we extracted high-accuracy photometry and constructed color-magnitude diagrams. We exploit appropriate combination of colors and magnitudes which are powerful tools to identify multiple stellar populations, like B versus U-B and V versus c_{U,B,I}=(U-B)-(B-I) CMDs. We confirm previous findings of a split MS in NGC 6752 and NGC 6121. Apart from the extreme case of omega Centauri, this is the first detection of multiple MS from ground-based photometry. For NGC 6752 and NGC 6121 we compare the number ratio of the blue MS to the red MS in the cluster outskirts with the fraction ...

  15. Unveiling the Nature of the 321 s Modulation in RX J0806.3+1527: Near-Simultaneous Chandra and VLT Observations

    CERN Document Server

    Israel, G L; Stella, L; Mauche, C W; Campana, S; Marconi, G; Hummel, W; Mereghetti, S; Munari, U; Negueruela, I

    2003-01-01

    We report on the first near-simultaneous X-ray and optical observations of RX J0806.3+1527. The source is believed to be a 321s orbital period ultra-compact binary system hosting an X-ray emitting white dwarf. Data were obtained with Chandra and the ESO Very Large Telescope (VLT) in November 2001. We found an optical/X-ray phase-shift in the periodic modulation of about 0.5, strongly favoring the existance of two distinct emission regions in the two bands (for the pulsed fluxes). The Chandra data allow us to study, for the first time, the spectral continuum of RX J0806.3+1527 in soft X-rays. This was well fitted by a blackbody spectrum with kT about 65eV and hydrogen column density of N_H about 5 x 10^20 cm^-2. The average (unabsorbed) source 0.1-2.5 keV luminosity during the modulation-on is L_X about 5 x 10^32 erg s^-1 (assuming a distance of 500pc). Such a value is lower than the luminosity expected if stable mass transfer between two white dwarfs were driven by gravitational radiation. Evidence for absorp...

  16. CLASH-VLT: The stellar mass function and stellar mass density profile of the z=0.44 cluster of galaxies MACS J1206.2-0847

    CERN Document Server

    Annunziatella, M; Mercurio, A.; Nonino, M.; Rosati, P.; Balestra, I.; Presotto, V.; Girardi, M.; Gobat, R.; Grillo, C.; Medezinski, E.; Kelson, D.; Postman, M.; Scodeggio, M.; Brescia, M.; Sartoris, B.; Demarco, R.; Fritz, A.; Koekemoer, A.; Lemze, D.; Lombardi, M.; Bradley, L.; Coe, D.; Donahue, M.; Regös, E.; Umetsu, K.; Vanzella, E.; Infante, L.; Kuchner, U.; Maier, C.; Verdugo, M.; Ziegler, B.

    2014-01-01

    Context. The study of the galaxy stellar mass function (SMF) in relation to the galaxy environment and the stellar mass density profile, rho(r), is a powerful tool to constrain models of galaxy evolution. Aims. We determine the SMF of the z=0.44 cluster of galaxies MACS J1206.2-0847 separately for passive and star-forming (SF) galaxies, in different regions of the cluster, from the center out to approximately 2 virial radii. We also determine rho(r) to compare it to the number density and total mass density profiles. Methods. We use the dataset from the CLASH-VLT survey. Stellar masses are obtained by SED fitting on 5-band photometric data obtained at the Subaru telescope. We identify 1363 cluster members down to a stellar mass of 10^9.5 Msolar. Results. The whole cluster SMF is well fitted by a double Schechter function. The SMFs of cluster SF and passive galaxies are statistically different. The SMF of the SF cluster galaxies does not depend on the environment. The SMF of the passive population has a signif...

  17. VLT/UVES observations of peculiar alpha abundances in a sub-DLA at z ~ 1.8 towards the quasar B1101-26

    CERN Document Server

    Fox, Anne; Fechner, Cora

    2014-01-01

    We present a detailed analysis of chemical abundances in a sub-damped Lyman alpha absorber at z=1.839 towards the quasar B1101-26, based on a very-high-resolution (R ~ 75,000) and high-signal-to-noise (S/N >100) spectrum observed with the UV Visual Echelle spectrograph (UVES) installed on the ESO Very Large Telescope (VLT). The absorption line profiles are resolved into a maximum of eleven velocity components spanning a rest-frame velocity range of 200 km/s. Detected ions include CII, CIV, NII, OI, MgI, MgII, AlII, AlIII, SiII, SiIII, SiIV, FeII, and possibly SII. The total neutral hydrogen column density is log N(HI) = 19.48 +/- 0.01. From measurements of column densities and Doppler parameters we estimate element abundances of the above-given elements. The overall metallicity, as traced by [OI/HI], is -1.56 +/- 0.01. For the nitrogen-to-oxygen ratio we derive an upper limit of [NI/OI] < -0.65, which suggests a chemically young absorption line system. This is supported by a supersolar alpha/Fe ratio of [S...

  18. A VLT spectroscopic survey of RX J0152.7-1357, a forming cluster of galaxies at z=0.837

    CERN Document Server

    Demarco, R; Lidman, C E; Homeier, N L; Scannapieco, E; Benítez, N; Mainieri, V; Nonino, M; Girardi, M; Stanford, S A; Tozzi, P; Borgani, S; Silk, J; Squires, G; Broadhurst, T J

    2004-01-01

    We present the results of an extensive spectroscopic survey of RX J0152.7-1357, one of the most massive distant clusters of galaxies known. Multi-object spectroscopy, carried out with FORS1 and FORS2 on the ESO Very Large Telescope (VLT), has allowed us to measure more than 200 redshifts in the cluster field and to confirm 102 galaxies as cluster members. The mean redshift of the cluster is $z=0.837 \\pm 0.001$ and we estimate the velocity dispersion of the overall cluster galaxy distribution to be $\\sim 1600 \\mathrm{km \\ s^{-1}}$. The distribution of cluster members is clearly irregular, with two main clumps that follow the X-ray cluster emission mapped by Chandra. A third clump of galaxies to the east of the central structure and at the cluster redshift has also been identified. The two main clumps have velocity dispersions of $\\sim919$ and $\\sim737 \\mathrm{km s^{-1}}$ respectively, and the peculiar velocity of the two clumps suggests that they will merge into a single more massive cluster. A segregation in ...

  19. The VISIR@VLT Mid-IR view of 47Tuc: A further step in solving the puzzle of RGB mass loss

    CERN Document Server

    Momany, Y; Smette, A; Bayo, A; Girardi, L; Marconi, G; Milone, A P; Bressan, A

    2011-01-01

    There is an ongoing debate regarding the onset luminosity of dusty mass loss in population-II red giant stars. In this paper we present VISIR@VLT MIR 8.6 micron imaging of 47Tuc, centre of attention of a number of space-based Spitzer observations and studies. The VISIR high resolution (diffraction limited) observations allow excellent matching to existing optical Hubble space telescope catalogues. The optical-MIR coverage of the inner 1.15 arcmin of the cluster provide the cleanest possible, blending-free, sampling of the upper 3 magnitudes of the giant branch. Our diagrams show no evidence of faint giants with MIR-excess. A combined NIR-MIR diagram further confirms the near absence of dusty red giants. Dusty red giants and asymptotic giant stars are confined to the 47Tuc long period variables population. In particular, dusty red giants are limited to the upper one 8.6 micron magnitude below the giant branch tip. This particular luminosity level corresponds to ~1000 solar luminosity, suggested in previous det...

  20. The Lyman-alpha forest of a Lyman Break Galaxy VLT Spectra of MS1512-cB58 at z=2.724

    CERN Document Server

    Savaglio, S; Padovani, P

    2001-01-01

    The high redshift galaxy MS1512-cB58 (z=2.724, m_V=20.64) has been observed with the very efficient high resolution echelle spectrograph VLT/UVES. Although this is a very challenging observational program for a Southern hemisphere telescope (the galaxy is located at +36 deg declination), high resolution spectra (FWHM ~ 26 km/s) have revealed, with unprecedented detail along a galaxy sight line, the Lyman-alpha forest due to intervening clouds in the intergalactic medium (IGM). The mean depression D_A due to IGM absorption blueward of the galaxy Ly-alpha wavelength and the number density dn/dz of Ly-alpha clouds have been compared with equivalent results obtained for QSO sight lines at similar redshifts. Our results indicate a possible excess of absorption close to the galaxy. The mean depression at ~ 150 h_65^-1 Mpc comoving (Omega_m=0.3, Omega_Lambda=0.7) from the galaxy is D_A=0.36+/-0.03, to be compared with 0.22+/-0.04, expected from a best fit to QSO sight lines. In the same region (z=2.610), the number ...

  1. VLT/X-shooter spectroscopy of the candidate black-hole X-ray binary MAXI J1659-152 in outburst

    CERN Document Server

    Kaur, Ramanpreet; Ellerbroek, Lucas E; Russell, David M; Altamirano, Diego; Wijnands, Rudy; Yang, Yi-Jung; D'Avanzo, Paolo; Postigo, Antonio de Ugarte; Flores, Hector; Fynbo, Johan P U; Goldoni, Paolo; Thone, Christina C; van der Horst, Alexander; van der Klis, Michiel; Kouveliotou, Chryssa; Wiersema, Klaas; Kuulkers, Erik

    2012-01-01

    We present the optical to near-infrared spectrum of MAXI J1659-152, during the onset of its 2010 X-ray outburst. The spectrum was obtained with X-shooter on the ESO - Very Large Telescope (VLT) early in the outburst simultaneous with high quality observations at both shorter and longer wavelengths. At the time of the observations, the source was in the low-hard state. The X-shooter spectrum includes many broad (~2000 km/s), double-peaked emission profiles of H, HeI, HeII, characteristic signatures of a low-mass X-ray binary during outburst. We detect no spectral signatures of the low-mass companion star. The strength of the diffuse interstellar bands results in a lower limit to the total interstellar extinction of Av ~ 0.4 mag. Using the neutral hydrogen column density obtained from the X-ray spectrum we estimate Av ~1 mag. The radial-velocity structure of the interstellar NaI D and CaII H & K lines results in a lower limit to the distance of ~ 4 +/- 1 kpc, consistent with previous estimates. With this di...

  2. Voice-coil technology for the E-ELT M4 Adaptive Unit

    Science.gov (United States)

    Gallieni, D.; Tintori, M.; Mantegazza, M.; Anaclerio, E.; Crimella, L.; Acerboni, M.; Biasi, R.; Angerer, G.; Andrigettoni, M.; Merler, A.; Veronese, D.; Carel, J.-L.; Marque, G.; Molinari, E.; Tresoldi, D.; Toso, G.; Spanó, P.; Riva, M.; Mazzoleni, R.; Riccardi, A.; Mantegazza, P.; Manetti, M.; Morandini, M.; Vernet, E.; Hubin, N.; Jochum, L.; Madec, P.; Dimmler, M.; Koch, F.

    We present our design of the E-ELT M4 Adaptive Unit based on voice-coil driven deformable mirror technology. This technology was developed by INAF-Arcetri, Microgate and ADS team in the past 15 years and it has been adopted by a number of large ground based telescopes as the MMT, LBT, Magellan and lastly the VLT in the frame of the Adaptive Telescope Facility project. Our design is based on contactless force actuators made by permanent magnets glued on the back of the deformable mirror and coils mounted on a stiff reference structure. We use capacitive sensors to close a position loop co-located with each actuator. Dedicated high performance parallel processors are used to implement the local de-centralized control at actuator level and a centralized feed-forward computation of all the actuators forces. This allowed achieving in our previous systems dynamic performances well in line with the requirements of the M4 Adaptive Unit (M4AU) case. The actuator density of our design is in the order of 30-mm spacing for a figure of about 6000 actuators on the M4AU and it allows fulfilling the fitting error and corrections requirements of the E-ELT high order DM. Moreover, our contact-less technology makes the Deformable Mirror tolerant to up 5% actuators failures without spoiling system capability to reach its specified performances, besides allowing large mechanical tolerances between the reference structure and the deformable mirror. Finally, we present the Demonstration Prototype we are building in the frame of the M4AU Phase B study to measure the optical dynamical performances predicted by our design. Such a prototype will be fully representative of the M4AU features, in particular it will address the controllability of two adjacent segments of the 2-mm thick mirror and implement the actuators "brick" modular concept that has been adopted to dramatically improve the maintainability of the final unit.

  3. NRAO Green Bank Telescope (GBT)

    Data.gov (United States)

    Federal Laboratory Consortium — The largest fully steerable telescope in the world - the Robert C. Byrd Green Bank Telescope, began observations in Green Bank, West Virginia in 2000and is a wonder...

  4. Optical Space Telescope Assembly Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Optical Space Telescope Assembly (OSTA) task is to demonstrate the technology readiness of assembling large space telescopes on orbit in 2015. This task is an...

  5. VLT/SINFONI Observations of Europa: New Insights into the Surface Composition

    Science.gov (United States)

    Ligier, N.; Poulet, F.; Carter, J.; Brunetto, R.; Gourgeot, F.

    2016-06-01

    We present new insights into Europa’s surface composition on the global scale from linear spectral modeling of a high spectral resolution data set acquired during a ground-based observation campaign using SINFONI4, an adaptive optics near-infrared instrument on the Very Large Telescope (ESO). The spectral modeling confirms the typical “bullseye” distribution of sulfuric acid hydrate on the trailing hemisphere, which is consistent with Iogenic sulfur ion implantation. However, the traditional hypothesis of the presence of sulfate salts on the surface of the satellite is challenged as Mg-bearing chlorinated species (chloride, chlorate, and perchlorate) are found to provide improved spectral fits. The derived global distribution of Mg-chlorinated salts (and particularly chloride) is correlated with large-scale geomorphologic units such as chaos and darker areas, thus suggesting an endogenous origin. Based on the 1.65 μm water-ice absorption band shape and position, the surface temperature is estimated to be in the range 110-130 K, and water ice is found to be predominantly in its crystalline state rather than amorphous. While amorphous water ice exhibits a strong correlation with the expected intensity of the Ionian plasma torus bombardment, crystalline water ice is instead more associated with distinct geomorphological units. Endogenous processes such as jets and ice heating due to active geology may explain this relationship. Otherwise, no evidence of a correlation between grain size for the water ice and the sputtering rate has been detected so far.

  6. Progress in Space Solar Telescope

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper we will summarize the progress in the development of the Chinese Space Solar Telescope (SST) during the past few years. The main scientific objective of SST is to observe the fundamental structure of solar magnetic field with its 1-m optical telescope. The success of 1-m Swedish Solar Telescope and Hinode underscores the importance of this 1-m space telescope. In addition, some key technical problems have been solved.

  7. Uzaybimer Radio Telescope Control System

    Science.gov (United States)

    Balbay, R.; Öz, G. K.; Arslan, Ö.; Özeren, F. F.; Küçük, İ.

    2016-12-01

    A 13 meters former NATO radar is being converted into a radio telescope. The radio telescope is controlled by a system which has been developed at UZAYBİMER. The Telescope Control System(TCS) has been designed using modern industrial systems. TCS has been developed in LabView platform in which works Windows embedded OS. The position feedback used on radio telescopes is an industrial EtherCAT standard. ASCOM library is used for astronomical calculations.

  8. VLT/GIRAFFE spectroscopic observations of the metal-poor blue compact dwarf galaxy SBS 0335-052E

    Science.gov (United States)

    Izotov, Y. I.; Schaerer, D.; Blecha, A.; Royer, F.; Guseva, N. G.; North, P.

    2006-11-01

    Aims.We present two-dimensional spectroscopy of the extremely metal-deficient blue compact dwarf (BCD) galaxy SBS 0335-052E to study physical conditions, element abundances and kinematical properties of the ionised gas in this galaxy. Methods: .Observations were obtained in the spectral range λ3620-9400 Å with the imaging spectrograph GIRAFFE on the UT2 of the Very Large Telescope (VLT). These observations are the first ones carried out so far with GIRAFFE in the ARGUS mode which allows one to simultaneously obtain 308 spectra covering a 11.4 arcsec×7.3 arcsec region. Results: .We produced images of SBS 0335-052E in the continuum and in emission lines of different stages of excitation. While the maximum of emission in the majority of lines, including the strong lines Hβ 4861 Å, Hα 6563 Å, [O iii] 4363,5007 Å, [O ii] 3726,3729 Å, coincides with the youngest south-eastern star clusters 1 and 2, the emission of He II 4686 Å line is offset to the more evolved north-west clusters 4, 5. This suggests that hard ionising radiation responsible for the He II λ4686 Å emission is not related to the most massive youngest stars, but rather is related to fast radiative shocks. This conclusion is supported by the kinematical properties of the ionised gas from the different emission lines as the velocity dispersion in the He II λ4686 Å line is systematically higher, by ~50-100%, than that in other lines. The variations of the emission line profiles suggest the presence of an ionised gas outflow in the direction perpendicular to the galaxy disk. We find a relatively high electron number density Ne of several hundred cm-3 in the brightest part of SBS 0335-052E. There is a small gradient of the electron temperature Te and oxygen abundance from the East to the West with systematically higher Te and lower 12+log O/H in the western part of the galaxy. The oxygen abundances for the whole H II region and its brightest part are 12 + log O/H = 7.29 ± 0.02 and 7.31 ± 0

  9. First light of the VLT planet finder SPHERE. I. Detection and characterization of the substellar companion GJ 758 B

    Science.gov (United States)

    Vigan, A.; Bonnefoy, M.; Ginski, C.; Beust, H.; Galicher, R.; Janson, M.; Baudino, J.-L.; Buenzli, E.; Hagelberg, J.; D'Orazi, V.; Desidera, S.; Maire, A.-L.; Gratton, R.; Sauvage, J.-F.; Chauvin, G.; Thalmann, C.; Malo, L.; Salter, G.; Zurlo, A.; Antichi, J.; Baruffolo, A.; Baudoz, P.; Blanchard, P.; Boccaletti, A.; Beuzit, J.-L.; Carle, M.; Claudi, R.; Costille, A.; Delboulbé, A.; Dohlen, K.; Dominik, C.; Feldt, M.; Fusco, T.; Gluck, L.; Girard, J.; Giro, E.; Gry, C.; Henning, T.; Hubin, N.; Hugot, E.; Jaquet, M.; Kasper, M.; Lagrange, A.-M.; Langlois, M.; Le Mignant, D.; Llored, M.; Madec, F.; Martinez, P.; Mawet, D.; Mesa, D.; Milli, J.; Mouillet, D.; Moulin, T.; Moutou, C.; Origné, A.; Pavlov, A.; Perret, D.; Petit, C.; Pragt, J.; Puget, P.; Rabou, P.; Rochat, S.; Roelfsema, R.; Salasnich, B.; Schmid, H.-M.; Sevin, A.; Siebenmorgen, R.; Smette, A.; Stadler, E.; Suarez, M.; Turatto, M.; Udry, S.; Vakili, F.; Wahhaj, Z.; Weber, L.; Wildi, F.

    2016-03-01

    GJ 758 B is a brown dwarf companion to a nearby (15.76%) solar-type, metal-rich (M / H = + 0.2 dex) main-sequence star (G9V) that was discovered with Subaru/HiCIAO in 2009. From previous studies, it has drawn attention as being the coldest (~600 K) companion ever directly imaged around a neighboring star. We present new high-contrast data obtained during the commissioning of the SPHERE instrument at the Very Large Telescope (VLT). The data was obtained in Y-, J-, H-, and Ks-bands with the dual-band imaging (DBI) mode of IRDIS, thus providing a broad coverage of the full near-infrared (near-IR) range at higher contrast and better spectral sampling than previously reported. In this new set of high-quality data, we report the re-detection of the companion, as well as the first detection of a new candidate closer-in to the star. We use the new eight photometric points for an extended comparison of GJ 758 B with empirical objects and four families of atmospheric models. From comparison to empirical object, we estimate a T8 spectral type, but none of the comparison objects can accurately represent the observed near-IR fluxes of GJ 758 B. From comparison to atmospheric models, we attribute a Teff = 600 ± 100 K, but we find that no atmospheric model can adequately fit all the fluxes of GJ 758 B. The lack of exploration of metal enrichment in model grids appears as a major limitation that prevents an accurate estimation of the companion physical parameters. The photometry of the new candidate companion is broadly consistent with L-type objects, but a second epoch with improved photometry is necessary to clarify its status. The new astrometry of GJ 758 B shows a significant proper motion since the last epoch. We use this result to improve the determination of the orbital characteristics using two fitting approaches: Least-Squares Monte Carlo and Markov chain Monte Carlo. We confirm the high-eccentricity of the orbit (peak at 0.5), and find a most likely semi-major axis of

  10. Fingerprints of endogenous process on Europa through linear spectral modeling of ground-based observations (ESO/VLT/SINFONI)

    Science.gov (United States)

    Ligier, Nicolas; Carter, John; Poulet, François; Langevin, Yves; Dumas, Christophe; Gourgeot, Florian

    2016-04-01

    Jupiter's moon Europa harbors a very young surface dated, based on cratering rates, to 10-50 M.y (Zahnle et al. 1998, Pappalardo et al. 1999). This young age implies rapid surface recycling and reprocessing, partially engendered by a global salty subsurface liquid ocean that could result in tectonic activity (Schmidt et al. 2011, Kattenhorn et al. 2014) and active plumes (Roth et al. 2014). The surface of Europa should contain important clues about the composition of this sub-surface briny ocean and about the potential presence of material of exobiological interest in it, thus reinforcing Europa as a major target of interest for upcoming space missions such as the ESA L-class mission JUICE. To perform the investigation of the composition of the surface of Europa, a global mapping campaign of the satellite was performed between October 2011 and January 2012 with the integral field spectrograph SINFONI on the Very Large Telescope (VLT) in Chile. The high spectral binning of this instrument (0.5 nm) is suitable to detect any narrow mineral signature in the wavelength range 1.45-2.45 μm. The spatially resolved spectra we obtained over five epochs nearly cover the entire surface of Europa with a pixel scale of 12.5 by 25 m.a.s (~35 by 70 km on Europa's surface), thus permitting a global scale study. Until recently, a large majority of studies only proposed sulfate salts along with sulfuric acid hydrate and water-ice to be present on Europa's surface. However, recent works based on Europa's surface coloration in the visible wavelength range and NIR spectral analysis support the hypothesis of the predominance of chlorine salts instead of sulfate salts (Hand & Carlson 2015, Fischer et al. 2015). Our linear spectral modeling supports this new hypothesis insofar as the use of Mg-bearing chlorines improved the fits whatever the region. As expected, the distribution of sulfuric acid hydrate is correlated to the Iogenic sulfur ion implantation flux distribution (Hendrix et al

  11. VLT transit and occultation photometry for the bloated planet CoRoT-1b

    OpenAIRE

    Gillon, Michaël; Demory, B. -O.; Triaud, A. H. M. J.; Barman, T; Hebb, L.; Montalban Iglesias, Josefa; Maxted, P.; Queloz, D; Deleuil, M.; Magain, Pierre

    2009-01-01

    We present VLT eclipse photometry for the giant planet CoRoT-1b. We observed a transit in the R-band filter and an occultation in a narrow filter centered on 2.09 microns. Our analysis of this new photometry and published radial velocities, in combination with stellar-evolutionary modeling, leads to a planetary mass and radius of 1.07 (+0.13,-0.18) M_Jup and 1.45 (+0.07,-0.13) R_Jup, confirming the very low density previously deduced from CoRoT photometry. The large occultation depth that we ...

  12. Comparing NEO Search Telescopes

    CERN Document Server

    Myhrvold, Nathan

    2015-01-01

    Multiple terrestrial and space-based telescopes have been proposed for detecting and tracking near-Earth objects (NEOs). Detailed simulations of the search performance of these systems have used complex computer codes that are not widely available, which hinders accurate cross- comparison of the proposals and obscures whether they have consistent assumptions. Moreover, some proposed instruments would survey infrared (IR) bands, whereas others would operate in the visible band, and differences among asteroid thermal and visible light models used in the simulations further complicate like-to-like comparisons. I use simple physical principles to estimate basic performance metrics for the ground-based Large Synoptic Survey Telescope and three space-based instruments - Sentinel, NEOCam, and a Cubesat constellation. The performance is measured against two different NEO distributions, the Bottke et al. distribution of general NEOs, and the Veres et al. distribution of earth impacting NEO. The results of the comparis...

  13. The ANTARES Neutrino Telescope

    CERN Document Server

    Perrina, Chiara

    2015-01-01

    At about 40 km off the coast of Toulon (France), anchored at 2475 m deep in the Mediterranean Sea, there is ANTARES: the first undersea neutrino telescope and the only one currently operating. The detector consists of 885 photomultiplier tubes arranged into 12 strings of 450-metres high, with the aim to detect the Cherenkov light induced by the charged superluminal interaction products of neutrinos. Its main scientific target is the search for high-energy (TeV and beyond) neutrinos from cosmic accelerators, as predicted by hadronic interaction models, and the measurement of the cosmic neutrino diffuse flux, focusing in particular on events coming from below the horizon (up-going events) in order to significantly reduce the atmospheric muons background. Thanks to the development of a strategy for the identification of neutrinos coming from above the horizon (down-going events) the field of view of the telescope will be extended.

  14. Telescopic limiting magnitudes

    Science.gov (United States)

    Schaefer, Bradley E.

    1990-01-01

    The prediction of the magnitude of the faintest star visible through a telescope by a visual observer is a difficult problem in physiology. Many prediction formulas have been advanced over the years, but most do not even consider the magnification used. Here, the prediction algorithm problem is attacked with two complimentary approaches: (1) First, a theoretical algorithm was developed based on physiological data for the sensitivity of the eye. This algorithm also accounts for the transmission of the atmosphere and the telescope, the brightness of the sky, the color of the star, the age of the observer, the aperture, and the magnification. (2) Second, 314 observed values for the limiting magnitude were collected as a test of the formula. It is found that the formula does accurately predict the average observed limiting magnitudes under all conditions.

  15. Everyday Radio Telescope

    CERN Document Server

    Mandal, Pranshu; Kumar, Pratik; Yelikar, Anjali; Soni, Kanchan; T, Vineeth Krishna

    2016-01-01

    We have developed an affordable, portable college level radio telescope for amateur radio astronomy which can be used to provide hands-on experience with the fundamentals of a radio telescope and an insight into the realm of radio astronomy. With our set-up one can measure brightness temperature and flux of the Sun at 11.2 GHz and calculate the beam width of the antenna. The set-up uses commercially available satellite television receiving system and parabolic dish antenna. We report the detection of point sources like Saturn and extended sources like the galactic arm of the Milky way. We have also developed python pipeline, which are available for free download, for data acquisition and visualization.

  16. Origins Space Telescope

    Science.gov (United States)

    Cooray, Asantha R.; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. I will summarize the OST STDT, mission design and instruments, key science drivers, and the study plan over the next two years.

  17. The Cherenkov Telescope Array

    Science.gov (United States)

    Connaughton, Valerie

    2014-03-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort dedicated to the design and operation of the next-generation ground-based very high-energy gamma-ray observatory. CTA will improve by about one order of magnitude the sensitivity with respect to the current major arrays (VERITAS, H.E.S.S., and MAGIC) in the core energy range of 100 GeV to 10 TeV, and will extend the viability of the imaging atmospheric Cherenkov technique (IACT) down to tens of GeV and above 100 TeV. In order to achieve such improved performance at both a northern and southern CTA site, four 23m diameter Large Size Telescopes (LST) optimized for low energy gamma rays will be deployed close to the centre of the array. A larger number of Medium Size Telescopes (MST) will be optimized for the core IACT energy range. The southern site will include 25 12m single-mirror MSTs and a US contribution of up to 24 novel dual-mirror design Schwarzschild-Couder (SC) type MSTs with a primary mirror of 9.5m diameter, and will also include an array of Small Size Telescopes (SST) to observe the highest-energy gamma rays from galactic sources. The SSTs can be smaller and more widely separated because more energetic gamma rays produce a larger Cherenkov light pool with many photons. The SSTs achieve a large collection area by covering a wide (10 sq km) footprint on the ground. The CTA project is finishing its preparatory phase, and the pre-production phase will start this year. I will review the status and the expected performance of CTA as well as the main scientific goals for the observatory.

  18. [Galileo and his telescope].

    Science.gov (United States)

    Strebel, Christoph

    2006-01-01

    Galileo's publication of observations made with his newly reinvented telescope provoked a fierce debate. In April 1610 Martinus Horky, a young Bohemian astronomer, had an opportunity to make his own observations with Galileo's telescope in the presence of Antonio Magini and other astronomers. Horky and the other witnesses denied the adequacy of Galileo's telescope and therefore the bona fides of his discoveries. Kepler conjectured Horky as well as all his witnesses to be myopic. But Kepler's objection could not stop the publication of Horky's Peregrinatio contra nuncium sidereum (Modena, 1610), the first printed refutation of Galileo's Sidereus nuncius. In his treatise, Horky adresses four questions: 1) Do the four newly observed heavenly bodies actually exist? Horky denies their existence on various grounds: a) God, as every astronomer teaches, has created only seven moveable heavenly bodies and astronomical knowledge originates in God, too. b) Heavenly bodies are either stars or planets. Galileo's moveable heavenly bodies fit into neither category. c) If they do exist, why have they not already been observed by other scholars? Horky concludes that there are no such heavenly bodies. 2) What are these phenomena? They are purely artefactual, and produced by Galileo's telescope. 3) How are they like? Galileo's "stars" are so small as to be almost invisible. Galileo claims that he has measured their distances from each other. This however is impossible due to their diminutive size and other observational problems. Hence, Galileo's claim is a further proof that he is a fraud. 4) Why are they? For Galileo they are a chance to earn money but for astronomers like Horky they are a reason to offer thanks and honour to God. Horky's treatise was favourably received by the enemies of Galileo. But Kepler's critique was devastating. After calling on Kepler in Prague, Horky had to revoke the contents of his book.

  19. Fast Fourier transform telescope

    Science.gov (United States)

    Tegmark, Max; Zaldarriaga, Matias

    2009-04-01

    We propose an all-digital telescope for 21 cm tomography, which combines key advantages of both single dishes and interferometers. The electric field is digitized by antennas on a rectangular grid, after which a series of fast Fourier transforms recovers simultaneous multifrequency images of up to half the sky. Thanks to Moore’s law, the bandwidth up to which this is feasible has now reached about 1 GHz, and will likely continue doubling every couple of years. The main advantages over a single dish telescope are cost and orders of magnitude larger field-of-view, translating into dramatically better sensitivity for large-area surveys. The key advantages over traditional interferometers are cost (the correlator computational cost for an N-element array scales as Nlog⁡2N rather than N2) and a compact synthesized beam. We argue that 21 cm tomography could be an ideal first application of a very large fast Fourier transform telescope, which would provide both massive sensitivity improvements per dollar and mitigate the off-beam point source foreground problem with its clean beam. Another potentially interesting application is cosmic microwave background polarization.

  20. Hubble Space Telescope satellite

    Science.gov (United States)

    Mitchell, R. E.

    1985-01-01

    The Hubble Space Telescope, named for the American astronomer Edwin Powell Hubble, will be the largest and most powerful astronomical instrument ever orbited. Placed above the obscuring effects of the earth's atmosphere in a 600-km orbit, this remotely-controlled, free-flying satellite observatory will expand the terrestrial-equivalent resolution of the universe by a factor of seven, or a volumetric factor of 350. This telescope has a 2.4-m primary mirror and can accommodate five scientific instruments (cameras, spectrographs and photometers). The optics are suitable for a spectral range from 1100 angstrom to 1 mm wavelength. With a projected service life of fifteen years, the spacecraft can be serviced on-orbit for replacement of degraded systems, to insert advanced scientific instruments, and to reboost the telescope from decayed altitudes. The anticipated image quality will be a result of extremely precise lambda/20 optics, stringent cleanliness, and very stable pointing: jitter will be held to less than 0.01 arcsecond for indefinite observation periods, consistent with instrument apertures as small as 0.1 arcsecond.

  1. Sm-Nd and Rb-Sr Isotopic Studies of Meteorite Kalahari 009: An Old VLT Mare Basalt

    Science.gov (United States)

    Shih, C.-Y.; Nyquist, L. E.; Reese, Y.; Bischoff, A.

    2008-01-01

    Lunar meteorite Kalahari 009 is a fragmental basaltic breccia contain ing various very-low-Ti (VLT) mare basalt clasts embedded in a fine-g rained matrix of similar composition. This meteorite and lunar meteorite Kalahari 008, an anorthositic breccia, were suggested to be paired mainly due to the presence of similar fayalitic olivines in fragment s found in both meteorites. Thus, Kalahari 009 probably represents a VLT basalt that came from a locality near a mare-highland boundary r egion of the Moon, as compared to the typical VLT mare basalt samples collected at Mare Crisium during the Luna-24 mission. The concordant Sm-Nd and Ar-Ar ages of such a VLT basalt (24170) suggest that the extrusion of VLT basalts at Mare Crisium occurred 3.30 +/- 0.05 Ga ag o. Previous age results for Kalahari 009 range from approximately 4.2 Ga by its Lu-Hf isochron age to 1.70?0.04 Ga of its Ar-Ar plateau ag e. However, recent in-situ U-Pb dating of phosphates in Kalahari 009 defined an old crystallization age of 4.35+/- 0.15 Ga. The authors su ggested that Kalahari 009 represents a cryptomaria basalt. In this r eport, we present Sm-Nd and Rb-Sr isotopic results for Kalahari 009, discuss the relationship of its age and isotopic characteristics to t hose of other L-24 VLT mare basalts and other probable cryptomaria ba salts represented by Apollo 14 aluminous mare basalts, and discuss it s petrogenesis.

  2. SOAR Telescope Progress Report

    Science.gov (United States)

    Sebring, T.; Cecil, G.; Krabbendam, V.

    1999-12-01

    The 4.3m SOAR telescope is fully funded and under construction. A partnership between the country of Brazil, NOAO, Michigan State University, and the University of North Carolina at Chapel Hill, SOAR is being designed for high-quality imaging and imaging spectroscopy in the optical and near-IR over a field of view up to 12' diameter. US astronomers outside MSU and UNC will access 30% of the observing time through the standard NOAO TAC process. The telescope is being designed to support remote and synoptic observations. First light is scheduled for July 2002 at Cerro Pachon in Chile, a site with median seeing of 2/3" at 500 nm. The telescope will be operated by CTIO. Corning Inc. has fused the mirror blanks from boules of ULE glass. RSI in Richardson, Texas and Raytheon Optical Systems Inc. in Danbury, Conn. are designing and will fabricate the mount and active optics systems, respectively. The mount supports an instrument payload in excess of 5000 kg, at 2 Nasmyth locations and 3 bent Cass. ports. The mount and facility building have space for a laser to generate an artificial AO guide star. LabVIEW running under the Linux OS on compactPCI hardware has been adopted to control all telescope, detector, and instrument systems. The primary mirror is 10 cm thick and will be mounted on 120 electro-mechanical actuators to maintain its ideal optical figure at all elevations. The position of the light-weighted secondary mirror is adjusted to maintain collimation through use of a Shack-Hartmann wavefront sensor. The tertiary mirror feeds instruments and also jitters at up to 50 Hz to compensate for telescope shake and atmosphere wavefront tilt. The dome is a steel framework, with fiberglass panels. Air in the observing volume will be exchanged with that outside every few minutes by using large fans under computer control. All systems will be assembled and checked at the manufacturer's facility, then shipped to Chile. A short integration period is planned, and limited science

  3. Lyman-α emitters in the context of hierarchical galaxy formation: predictions for VLT/MUSE surveys

    Science.gov (United States)

    Garel, T.; Guiderdoni, B.; Blaizot, J.

    2016-02-01

    The VLT/Multi Unit Spectrograph Explorer (MUSE) integral-field spectrograph can detect Lyα emitters (LAE) in the redshift range 2.8 ≲ z ≲ 6.7 in a homogeneous way. Ongoing MUSE surveys will notably probe faint Lyα sources that are usually missed by current narrow-band surveys. We provide quantitative predictions for a typical wedding-cake observing strategy with MUSE based on mock catalogues generated with a semi-analytic model of galaxy formation coupled to numerical Lyα radiation transfer models in gas outflows. We expect ≈1500 bright LAEs (FLyα ≳ 10-17 erg s-1 cm-2) in a typical shallow field (SF) survey carried over ≈100 arcmin2 , and ≈2000 sources as faint as 10-18 erg s-1 cm-2 in a medium-deep field (MDF) survey over 10 arcmin2 . In a typical deep field (DF) survey of 1 arcmin2 , we predict that ≈500 extremely faint LAEs (FLyα ≳ 4 × 10-19 erg s-1 cm-2) will be found. Our results suggest that faint Lyα sources contribute significantly to the cosmic Lyα luminosity and SFR budget. While the host haloes of bright LAEs at z ≈ 3 and 6 have descendants with median masses of 2 × 1012 and 5 × 1013 M⊙, respectively, the faintest sources detectable by MUSE at these redshifts are predicted to reside in haloes which evolve into typical sub-L* and L* galaxy haloes at z = 0. We expect typical DF and MDF surveys to uncover the building blocks of Milky Way-like objects, even probing the bulk of the stellar mass content of LAEs located in their progenitor haloes at z ≈ 3.

  4. ALMA telescope reaches new heights

    Science.gov (United States)

    2009-09-01

    the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, but also from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born and remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimetre wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology. More information The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO is the European partner in ALMA. ALMA, the largest astronomical project in existence, is a revolutionary telescope, comprising an array of 66 giant 12-metre and 7-metre diameter antennas observing at millimetre and submillimetre wavelengths. ALMA will start scientific observations in 2011. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a

  5. High-precision astrometry on the VLT/FORS1 at time scales of few days

    CERN Document Server

    Lazorenko, P F; Dominik, M; Pepe, F; Ségransan, D; Udry, S

    2007-01-01

    We investigate the accuracy of astrometric measurements with the VLT/FORS1 camera and consider potential applications. The study is based on two-epoch (2000 and 2002/2003) frame series of observations of a selected Galactic Bulge sky region that were obtained with FORS1 during four consecutive nights each. Reductions were carried out with a novel technique that eliminates atmospheric image motion and does not require a distinction between targets and reference objects. The positional astrometric precision was found to be limited only by the accuracy of the determination of the star photocentre, which is typically 200-300 microarcsec per single measurement for bright unsaturated stars B=18-19. Several statistical tests have shown that at time-scales of 1-4 nights the residual noise in measured positions is essentially a white noise with no systematic instrumental signature and no significant deviation from a Gaussian distribution. Some evidence of a good astrometric quality of the VLT for frames separated by t...

  6. VLT/FORS2 observations of the optical counterpart of the isolated neutron star RBS 1774

    CERN Document Server

    Mignani, R P; Turolla, R; Haberl, F; Cropper, M; Motch, C; Treves, A; Zampieri, L

    2011-01-01

    X-ray observations performed with ROSAT led to the discovery of a group (seven to date) of X-ray dim and radio-silent middle-aged isolated neutron stars (a.k.a. XDINSs), which are characterised by pure blackbody spectra (kT~40-100 eV), long X-ray pulsations (P=3-12 s), and appear to be endowed with relatively high magnetic fields, (B~10d13-14 G). RBS 1774 is one of the few XDINSs with a candidate optical counterpart, which we discovered with the VLT. We performed deep observations of RBS 1774 in the R band with the VLT to disentangle a non-thermal power-law spectrum from a Rayleigh-Jeans, whose contributions are expected to be very much different in the red part of the spectrum. We did not detect the RBS 1774 candidate counterpart down to a 3 sigma limiting magnitude of R~27. The constraint on its colour, (B-R)<0.6, rules out that it is a background object, positionally coincident with the X-ray source. Our R-band upper limit is consistent with the extrapolation of the B-band flux (assuming a 3 sigma uncer...

  7. Using the VLT to analyze the compact photoionized regions in NGC 3109

    Directory of Open Access Journals (Sweden)

    M. Peña

    2007-01-01

    Full Text Available Veinte nebulosas planetarias (NP y numerosas regiones HII compactas fueron detectadas en la galaxia irregular NGC3109, mediante imágenes \\en-línea" y \\fuera de línea" en [O III] 5007 obtenidas con el ESO VLT. Las NPs fueron seleccionadas como objetos estelares que no mostraran continuo estelar. Espectroscopia obtenida con el VLT FORS1 en modo multi-objeto ha permitido confirmar la naturaleza de NP para varias candidatas. Se ha obtenido también espectroscopia para varias regiones HII compactas. Los espectros son profundos de manera que muchos objetos muestran [O III] 4363 y se puede determinar la temperatura de las regiones, permitiendo analizar la composición química de NPs y regiones HII. Encontramos que las regiones HII muestran una composición química (O/H muy homogénea (en promedio 12 + log O/H = 7.79_0.10, en tanto que las NPs muestran variaciones grandes de composición química y un aparente enriquecimiento en oxígeno.

  8. VLT observations of the asymmetric Etched Hourglass Nebula, MyCn 18

    CERN Document Server

    Clyne, N; Lloyd, M; Matsuura, M; Singh, N; Meaburn, J

    2014-01-01

    Context. The mechanisms that form extreme bipolar planetary nebulae remain unclear. Aims. The physical properties, structure, and dynamics of the bipolar planetary nebula, MyCn 18, are investigated in detail with the aim of understanding the shaping mechanism and evolutionary history of this object. Methods. VLT infrared images, VLT ISAAC infrared spectra, and long-slit optical Echelle spectra are used to investigate MyCn 18. Morpho-kinematic modelling was used to firmly constrain the structure and kinematics of the source. A timescale analysis was used to determine the kinematical age of the nebula and its main components. Results. A spectroscopic study of MyCn 18's central and offset region reveals the detailed make-up of its nebular composition. Molecular hydrogen, atomic helium, and Bracket gamma emission are detected from the central regions of MyCn 18. ISAAC spectra from a slit position along the narrow waist of the nebula demonstrate that the ionised gas resides closer to the centre of the nebula than ...

  9. Flasher and muon-based calibration of the GCT telescopes proposed for the Cherenkov Telescope Array

    CERN Document Server

    Brown, Anthony M; Chadwick, Paula M; Daniel, Michael; White, Richard

    2015-01-01

    The GCT is a dual-mirror Small-Sized-Telescope prototype proposed for the Cherenkov Telescope Array. Calibration of the GCT's camera is primarily achieved with LED-based flasher units capable of producing $\\sim4$ ns FWHM pulses of 400 nm light across a large dynamic range, from 0.1 up to 1000 photoelectrons. The flasher units are housed in the four corners of the camera's focal plane and illuminate it via reflection from the secondary mirror. These flasher units are adaptable to allow several calibration scenarios to be accomplished: camera flat-fielding, linearity measurements (up to and past saturation), and gain estimates from both single pe measurements and from the photon statistics at various high illumination levels. In these proceedings, the performance of the GCT flashers is described, together with ongoing simulation work to quantify the efficiency of using muon rings as an end-to-end calibration for the optical throughput of the GCT.

  10. Development, validity, and normative data study for the 12-word Philadelphia Verbal Learning Test [czP(r)VLT-12] among older and very old Czech adults.

    Science.gov (United States)

    Bezdicek, Ondrej; Libon, David J; Stepankova, Hana; Panenkova, Erika; Lukavsky, Jiri; Garrett, Kelly Davis; Lamar, Melissa; Price, Catherine C; Kopecek, Miloslav

    2014-01-01

    The aim of the present study was to assess the validity of a 12-word Czech version of the Philadelphia (repeatable) Verbal Learning Test [czP(r)VLT-12]. The construction of the czP(r)VLT-12 was modeled after the California Verbal Learning Test (CVLT) and the nine-word Philadelphia (repeatable) Verbal Learning Test [P(r)VLT]. The czP(r)VLT-12 was constructed from a large corpus of old (60-74) and very old (75-96) Czech adults (n = 540). Participants met strict inclusion criteria for the absence of any active or past neurodegenerative disorders and performed within normal limits on other neuropsychological measures. Principal component analysis (PCA) and correlations between czP(r)VLT-12 factor structure and other memory tests were conducted. The czP(r)VLT-12 produced a four-factor solution, accounting for 70.90% of variance, with factors related to: (1) recall, (2) extra-list intrusion errors/recognition foils, (3) interference, and (4) acquisition rate; a solution similar to the CVLT and P(r)VLT. Increasing age resulted in a decline in most czP(r)VLT-12 indices, women outperformed men, and higher education led to higher scores. Memory performance in normal aging did not correlate with instrumental activities of daily living. Low, but significant, correlations were seen with other tests of cognitive performance (divergent validity). Appendices are available that provide normed percentile estimates of individual czP(r)VLT-12 performance stratified by age, education, and gender. In accordance with previous studies, these results demonstrate the usefulness of czP(r)VLT-12 in assessing declarative memory in older adults.

  11. The Planck Telescope reflectors

    Science.gov (United States)

    Stute, Thomas

    2004-09-01

    The mechanical division of EADS-Astrium GmbH, Friedrichshafen is currently engaged with the development, manufacturing and testing of the advanced dimensionally stable composite reflectors for the ESA satellite borne telescope Planck. The objective of the ESA mission Planck is to analyse the first light that filled the universe, the cosmic microwave background radiation. Under contract of the Danish Space Research Institute and ESA EADS-Astrium GmbH is developing the all CFRP primary and secondary reflectors for the 1.5-metre telescope which is the main instrument of the Planck satellite. The operational frequency ranges from to 25 GHz to 1000 GHz. The demanding high contour accuracy and surface roughness requirements are met. The design provides the extreme dimensional stability required by the cryogenic operational environment at around 40 K. The elliptical off-axis reflectors display a classical lightweight sandwich design with CFRP core and facesheets. Isostatic mounts provide the interfaces to the telescope structure. Protected VDA provides the reflecting surface. The manufacturing is performed at the Friedrichshafen premises of EADS-Space Transportation GmbH, the former Dornier composite workshops. Advanced manufacturing technologies like true angle lay-up by CNC fibre placement and filament winding are utilized. The protected coating is applied at the CAHA facilities at the Calar Alto Observatory, Spain. The exhaustive environmental testing is performed at the facilities of IABG, Munich (mechanical testing) and for the cryo-optical tests at CSL Liege. The project is in advanced state with both Qualification Models being under environmental testing. The flight models will be delivered in 2004. The paper gives an overview over the requirements and the main structural features how these requirements are met. Special production aspects and available test results are reported.

  12. Integration of the instrument control electronics for the ESPRESSO spectrograph at ESO-VLT

    Science.gov (United States)

    Baldini, V.; Calderone, G.; Cirami, R.; Coretti, I.; Cristiani, S.; Di Marcantonio, P.; Mégevand, D.; Riva, M.; Santin, P.

    2016-07-01

    ESPRESSO, the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations of the ESO - Very Large Telescope site, is now in its integration phase. The large number of functions of this complex instrument are fully controlled by a Beckhoff PLC based control electronics architecture. Four small and one large cabinets host the main electronic parts to control all the sensors, motorized stages and other analogue and digital functions of ESPRESSO. The Instrument Control Electronics (ICE) is built following the latest ESO standards and requirements. Two main PLC CPUs are used and are programmed through the TwinCAT Beckhoff dedicated software. The assembly, integration and verification phase of ESPRESSO, due to its distributed nature and different geographical locations of the consortium partners, is quite challenging. After the preliminary assembling and test of the electronic components at the Astronomical Observatory of Trieste and the test of some electronics and software parts at ESO (Garching), the complete system for the control of the four Front End Unit (FEU) arms of ESPRESSO has been fully assembled and tested in Merate (Italy) at the beginning of 2016. After these first tests, the system will be located at the Geneva Observatory (Switzerland) until the Preliminary Acceptance Europe (PAE) and finally shipped to Chile for the commissioning. This paper describes the integration strategy of the ICE workpackage of ESPRESSO, the hardware and software tests that have been performed, with an overall view of the experience gained during these project's phases.

  13. The Cherenkov Telescope Array

    CERN Document Server

    Bigongiari, Ciro

    2016-01-01

    The Cherenkov Telescope Array (CTA) is planned to be the next generation ground based observatory for very high energy (VHE) gamma-ray astronomy. Gamma-rays provide a powerful insight into the non-thermal universe and hopefully a unique probe for new physics. Imaging Cherenkov telescopes have already discovered more than 170 VHE gamma-ray emitters providing plentiful of valuable data and clearly demonstrating the power of this technique. In spite of the impressive results there are indications that the known sources represent only the tip of the iceberg. A major step in sensitivity is needed to increase the number of detected sources, observe short time-scale variability and improve morphological studies of extended sources. An extended energy coverage is advisable to observe far-away extragalactic objects and improve spectral analysis. CTA aims to increase the sensitivity by an order of magnitude compared to current facilities, to extend the accessible gamma-ray energies from a few tens of GeV to a hundred o...

  14. Large Size Telescope Report

    CERN Document Server

    Mazin, D; Teshima, M

    2016-01-01

    The Cherenkov Telescope Array (CTA) observatory will be deployed over two sites in the two hemispheres. Both sites will be equipped with four Large Size Telescopes (LSTs), which are crucial to achieve the science goals of CTA in the 20-200 GeV energy range. Each LST is equipped with a primary tessellated mirror dish of 23 m diameter, supported by a structure made mainly of carbon fibre reinforced plastic tubes and aluminum joints. This solution guarantees light weight (around 100 tons), essential for fast repositioning to any position in the sky in <20 seconds. The camera is composed of 1855 photomultiplier tubes and embeds the control, readout and trigger electronics. The detailed design is now complete and production of the first LST, which will serve as a prototype for the remaining seven, is ongoing. The installation of the first LST at the Roque de los Muchachos Observatory on the Canary island of La Palma (Spain) started in July 2016. In this paper we will outline the technical solutions adopted to f...

  15. Magellan Telescopes operations 2008

    Science.gov (United States)

    Osip, David J.; Phillips, Mark M.; Palunas, Povilas; Perez, Frank; Leroy, M.

    2008-07-01

    The twin 6.5m Magellan Telescopes have been in routine operations at the Las Campanas Observatory in the Chilean Andes since 2001 and 2002 respectively. The telescopes are owned and operated by Carnegie for the benefit of the Magellan consortium members (Carnegie Institution of Washington, Harvard University, the University of Arizona, Massachusetts Institute of Technology, and the University of Michigan). This paper provides an up to date review of the scientific, technical, and administrative structure of the 'Magellan Model' for observatory operations. With a modest operations budget and a reasonably small staff, the observatory is operated in the "classical" mode, wherein the visiting observer is a key member of the operations team. Under this model, all instrumentation is supplied entirely by the consortium members and the various instrument teams continue to play a critical support role beyond initial deployment and commissioning activities. Here, we present a critical analysis of the Magellan operations model and suggest lessons learned and changes implemented as we continue to evolve an organizational structure that can efficiently deliver a high scientific return for the investment of the partners.

  16. Large size telescope report

    Science.gov (United States)

    Mazin, D.; Cortina, J.; Teshima, M.

    2017-01-01

    The Cherenkov Telescope Array (CTA) observatory will be deployed over two sites in the two hemispheres. Both sites will be equipped with four Large Size Telescopes (LSTs), which are crucial to achieve the science goals of CTA in the 20-200 GeV energy range. Each LST is equipped with a primary tessellated mirror dish of 23 m diameter, supported by a structure made mainly of carbon fibre reinforced plastic tubes and aluminum joints. This solution guarantees light weight (around 100 tons), essential for fast repositioning to any position in the sky in <20 seconds. The camera is composed of 1855 photomultiplier tubes and embeds the control, readout and trigger electronics. The detailed design is now complete and production of the first LST, which will serve as a prototype for the remaining seven, is ongoing. The installation of the first LST at the Roque de los Muchachos Observatory on the Canary island of La Palma (Spain) started in July 2016. In this paper we will outline the technical solutions adopted to fulfill the design requirements, present results of element prototyping and describe the installation and operation plans.

  17. Deep space telescopes

    CERN Document Server

    CERN. Geneva

    2006-01-01

    The short series of seminars will address results and aims of current and future space astrophysics as the cultural framework for the development of deep space telescopes. It will then present such new tools, as they are currently available to, or imagined by, the scientific community, in the context of the science plans of ESA and of all major world space agencies. Ground-based astronomy, in the 400 years since Galileo’s telescope, has given us a profound phenomenological comprehension of our Universe, but has traditionally been limited to the narrow band(s) to which our terrestrial atmosphere is transparent. Celestial objects, however, do not care about our limitations, and distribute most of the information about their physics throughout the complete electromagnetic spectrum. Such information is there for the taking, from millimiter wavelengths to gamma rays. Forty years astronomy from space, covering now most of the e.m. spectrum, have thus given us a better understanding of our physical Universe then t...

  18. Astronomers Break Ground on Atacama Large Millimeter Array (ALMA) - World's Largest Millimeter Wavelength Telescope

    Science.gov (United States)

    2003-11-01

    , operations will be conducted from the Operations Support Facility ( ALMA OSF) , a compound located at a more comfortable altitude of 2,900 metres, between the cities of Toconao and San Pedro de Atacama. Phase 1 of the ALMA Project, which included the design and development, was completed in 2002. The beginning of Phase 2 happened on February 25, 2003, when the European Southern Observatory (ESO) and the US National Science Foundation (NSF) signed a historic agreement to construct and operate ALMA , cf. ESO PR 04/03 . Construction will continue until 2012; however, initial scientific observations are planned already from 2007, with a partial array of the first antennas. ALMA 's operation will progressively increase until 2012 with the installation of the remaining antennas. The entire project will cost approximately 600 million Euros. Earlier this year, the ALMA Board selected Professor Massimo Tarenghi , formerly manager of ESO's VLT Project, to become ALMA Director. He is confident that he and his team will succeed: "We may have a lot of hard work in front of us" , he said, "but all of us in the team are excited about this unique project. We are ready to work for the international astronomical community and to provide them in due time with an outstanding instrument allowing trailblazing research projects in many different fields of modern astrophysics" . How ALMA will work ALMA will be composed of 64 high-precision antennas, each 12 metres in diameter. The ALMA antennas can be repositioned, allowing the telescope to function much like the zoom lens on a camera. At its largest, ALMA will be 14 kilometers across. This will allow the telescope to observe fine-scale details of astronomical objects. At its smallest configuration, approximately 150 meters across, ALMA will be able to study the large-scale structures of these same objects. ALMA will function as an interferometer (according to the same basic principle as the VLT Interferometer (VLTI) at Paranal). This means that it

  19. Upgrade of the MAGIC telescopes

    CERN Document Server

    Mazin, Daniel; Garczarczyk, Markus; Giavitto, Gianluca; Sitarek, Julian

    2014-01-01

    The MAGIC telescopes are two Imaging Atmospheric Cherenkov Telescopes (IACTs) located on the Canary island of La Palma. With 17m diameter mirror dishes and ultra-fast electronics, they provide an energy threshold as low as 50 GeV for observations at low zenith angles. The first MAGIC telescope was taken in operation in 2004 whereas the second one joined in 2009. In 2011 we started a major upgrade program to improve and to unify the stereoscopic system of the two similar but at that time different telescopes. Here we report on the upgrade of the readout electronics and digital trigger of the two telescopes, the upgrade of the camera of the MAGIC I telescope as well as the commissioning of the system after this major upgrade.

  20. The VIMOS VLT Deep Survey :Evolution of the major merger rate since z~1 from spectroscopicaly confirmed galaxy pairs

    CERN Document Server

    de Ravel, L; Tresse, L; Bottini, D; Garilli, B; Le Brun, V; MacCagni, D; Scaramella, R; Scodeggio, M; Vettolani, G; Zanichelli, A; Adami, C; Arnouts, S; Bardelli, S; Bolzonella, M; Cappi, A; Charlot, S; Ciliegi, P; Contini, T; Foucaud, S; Franzetti, P; Gavignaud, I; Guzzo, L; Ilbert, O; Iovino, A; Lamareille, F; McCracken, H J; Marano, B; Marinoni, C; Mazure, A; Meneux, B; Merighi, R; Paltani, S; Pellò, R; Pollo, A; Pozzetti, L; Radovich, M; Vergani, D; Zamorani, G; Zucca, E; Bondi, M; Bongiorno, A; Brinchmann, J; Cucciati, O; De la Torre, S; Gregorini, L; Memeo, P; Pérez-Montero, E; Mellier, Y; Merluzzi, P; Temporin, S

    2008-01-01

    From the VIMOS VLT Deep Survey we use a sample of 6447 galaxies with I_{AB} 9.5 has been accreted through major merging events since z ~ 1, indicating that major mergers have contributed significantly to the growth in stellar mass density of bright galaxies over the last half of the life of the Universe.

  1. The Great Observatories Origins Deep Survey VLT/FORS2 spectroscopy in the GOODS-South Field

    NARCIS (Netherlands)

    Vanzella, E; Cristiani, S; Dickinson, M; Kuntschner, H; Moustakas, LA; Nonino, M; Rosati, P; Stern, D; Cesarsky, C; Ettori, S; Ferguson, HC; Fosbury, RAE; Giavalisco, M; Haase, J; Renzini, A; Rettura, A; Serra, P

    2005-01-01

    We present the first results of the ESO/ GOODS program of spectroscopy of faint galaxies in the Chandra Deep Field South ( CDF- S). 399 spectra of 303 unique targets have been obtained in service mode with the FORS2 spectrograph at the ESO/ VLT, providing 234 redshift determinations ( the median of

  2. X-shooter: UV-to-IR intermediate-resolution high-efficiency spectrograph for the ESO VLT

    NARCIS (Netherlands)

    D'Odorico, S.; Andersen, M.I.; Conconi, P.; De Caprio, V.; Delabre, B.; Di Marcantonio, P.; Dekker, H.; Downing, M.D.; Finger, G.; Groot, P.; Hanenburg, H.H.; Hammer, F.; Horville, D.; Hjorth, J.; Kaper, L.; Klougart, J.; Kjaergaard-Rasmussen, P.; Lizon, J.-L.; Marteaud, M.; Mazzoleni, R.; Michaelsen, N.; Pallavicini, R.; Rigal, F.; Santin, P.; Norup Soerensen, A.; Spano, P.; Venema, L.; Vola, P.; Zerbi, F.M.; Hasinger, G.; Turner, M.J.L.

    2004-01-01

    X-shooter is a single target spectrograph for the Cassegrain focus of one of the VLT UTs. It covers in a single exposure the spectral range from the UV to the H band with a possible extension into part of the K band. It is designed to maximize the sensitivity in this spectral range through the

  3. VizieR Online Data Catalog: O-stars in VLT-FLAMES Tarantula Survey (Ramirez-Agudelo+ 2013)

    Science.gov (United States)

    Ramirez-Agudelo, O. H.; Simon-Diaz, S.; Sana, H.; de Koter, A.; Sabin-Sanjulian, C.; de Mink, S. E.; Dufton, P. L.; Grafener, G.; Evans, C. J.; Herrero, A.; Langer, N.; Lennon, D. J.; Maiz Apellaniz, J.; Markova, N.; Najarro, F.; Puls, J.; Vink, J. S.

    2013-09-01

    Projected rotational velocity measurements of 216 O-type stars observed at multi-epochs as part as the VLT-FLAMES Tarantula Survey. We measured projected rotational velocities by means of a Fourier transform method and a profile fitting method applied on a set of isolated spectral lines. (2 data files).

  4. Design, analysis and testing of the Optical Tube Assemblies for the ESO VLT Four Laser Guide Star Facility

    NARCIS (Netherlands)

    Henselmans, R.; Nijkerk, M.D.; Lemmen, M.H.J.; Rijnveld, N.; Kamphues, F.G.

    2012-01-01

    TNO has developed the Optical Tube Assemblies (OTAs) for the ESO VLT Four Laser Guide Star Facility. The OTAs are Galilean 20x beam expanders, expanding a ∅15 mm input beam (25W, 589 nm CW) to a steerable ∅300 mm output beam. TNO has recently successfully completed acceptance testing of the four uni

  5. A high-resolution VLT/FLAMES study of individual stars in the centre of the Fornax dwarf spheroidal galaxy

    NARCIS (Netherlands)

    Letarte, B.; Hill, V.; Tolstoy, E.; Jablonka, P.; Shetrone, M.; Venn, K. A.; Spite, M.; Irwin, M. J.; Battaglia, G.; Helmi, A.; Primas, F.; François, P.; Kaufer, A.; Szeifert, T.; Arimoto, N.; Sadakane, K.

    2010-01-01

    For the first time we show the detailed, late-stage, chemical evolution history of a small nearby dwarf spheroidal galaxy in the Local Group. We present the results of a high-resolution (R ~ 20 000, λ = 5340-5620; 6120-6701) FLAMES/GIRAFFE abundance study at ESO/VLT of 81 photometrically selected, r

  6. A high-resolution VLT/FLAMES study of individual stars in the centre of the Fornax dwarf spheroidal galaxy

    NARCIS (Netherlands)

    Letarte, B.; Hill, V.; Tolstoy, E.; Jablonka, P.; Shetrone, M.; Venn, K. A.; Spite, M.; Irwin, M. J.; Battaglia, G.; Helmi, A.; Primas, F.; François, P.; Kaufer, A.; Szeifert, T.; Arimoto, N.; Sadakane, K.

    2010-01-01

    For the first time we show the detailed, late-stage, chemical evolution history of a small nearby dwarf spheroidal galaxy in the Local Group. We present the results of a high-resolution (R similar to 20 000, lambda = 5340-5620; 6120-6701) FLAMES/GIRAFFE abundance study at ESO/VLT of 81 photometrical

  7. National Large Solar Telescope of Russia

    Science.gov (United States)

    Demidov, Mikhail

    One of the most important task of the modern solar physics is multi-wavelength observations of the small-scale structure of solar atmosphere on different heights, including chromosphere and corona. To do this the large-aperture telescopes are necessary. At present time there several challenging projects of the large (and even giant) solar telescopes in the world are in the process of construction or designing , the most known ones among them are 4-meter class telescopes ATST in USA and EST in Europe. Since 2013 the development of the new Large Solar Telescope (LST) with 3 meter diameter of the main mirror is started in Russia as a part (sub-project) of National Heliogeophysical Complex (NHGC) of the Russian Academy of Sciences. It should be located at the Sayan solar observatory on the altitude more then 2000 m. To avoid numerous problems of the off-axis optical telescopes (despite of the obvious some advantages of the off-axis configuration) and to meet to available financial budget, the classical on-axis Gregorian scheme on the alt-azimuth mount has been chosen. The scientific equipment of the LST-3 will include several narrow-band tunable filter devices and spectrographs for different wavelength bands, including infrared. The units are installed either at the Nasmyth focus or/and on the rotating coude platform. To minimize the instrumental polarization the polarization analyzer is located near diagonal mirror after M2 mirror. High order adaptive optics is used to achieve the diffraction limited performances. It is expected that after some modification of the optical configuration the LST-3 will operate as an approximately 1-m mirror coronograph in the near infrared spectral lines. Possibilities for stellar observations during night time are provided as well.

  8. Grid Integration of Robotic Telescopes

    CERN Document Server

    Breitling, F; Enke, H

    2008-01-01

    Robotic telescopes and grid technology have made significant progress in recent years. Both innovations offer important advantages over conventional technologies, particularly in combination with one another. Here, we introduce robotic telescopes used by the Astrophysical Institute Potsdam as ideal instruments for building a robotic telescope network. We also discuss the grid architecture and protocols facilitating the network integration that is being developed by the German AstroGrid-D project. Finally, we present three user interfaces employed for this purpose.

  9. Near Earth Object Survey Telescope

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The Near Earth Object Survey Telescope (NEOST), located at the Xuyi station of the Purple Mountain Observatory, is a telescope with the most powerful detection capacity, the highest efficiency and the best performance in the fields of near Earth object survey and optical imaging in China. NEOST is an 171.8 Schmidt type telescope with a 1.20 meter primary mirror and a 1.04 meter corrector,

  10. Gamma-Ray Telescopes: 400 Years of Astronomical Telescopes

    Science.gov (United States)

    Gehrels, Neil; Cannizzo, John K.

    2010-01-01

    The last half-century has seen dramatic developments in gamma-ray telescopes, from their initial conception and development through to their blossoming into full maturity as a potent research tool in astronomy. Gamma-ray telescopes are leading research in diverse areas such as gamma-ray bursts, blazars, Galactic transients, and the Galactic distribution of Al-26.

  11. Revealing deuterium Balmer lines in HII regions with VLT-UVES

    CERN Document Server

    Hébrard, G; Walsh, J R; Vidal-Madjar, A; Ferlet, R

    2000-01-01

    The search for deuterium Balmer lines with VLT-UVES is reported in HII regions of the Galaxy and the Magellanic Clouds. The DI lines appear as faint, narrow emission features in the blue wings of the HI Balmer lines and can be distinguished from high-velocity HI emission. The previous identification to deuterium is re-inforced beyond doubt. The detection of D-alpha and D-beta in Orion (Hebrard et al. 2000) is confirmed and deuterium lines are now detected up to at least D-eta. The UVES observations provide the first detection of Balmer DI lines in four new HII regions (M 8, M 16, M 20, and DEM S 103 in SMC), demonstrating that these lines are of common occurence.

  12. NIX, the imager for ERIS: the AO instrument for the VLT

    Science.gov (United States)

    Pearson, David; Taylor, William; Davies, Ric; MacIntosh, Mike; Henry, David; Lunney, David; Waring, Chris; Gao, Xiaofeng; Lightfoot, John; Glauser, Adrian M.; Quanz, Sascha P.; Meyer, Michael R.; Schmid, Hans Martin; March, Stephen; Bachmann, Walter; Feuchtgruber, Helmut; George, Elizabeth; Sturm, Eckhard; Biller, Beth; Hinckley, Sasha; Kenworthy, Matthew; Amico, Paola; Glindemann, Andreas; Kasper, Marcus; Kuntschner, Harald; Dorn, Reinhold; Egner, Sebastian

    2016-08-01

    ERIS will be the next-generation AO facility on the VLT, combining the heritage of NACO imaging, with the spectroscopic capabilities of an upgraded SINFONI. Here we report on the all-new NIX imager that will deliver diffraction-limited imaging from the J to M band. The instrument will be equipped with both Apodizing Phase Plates and Sparse Aperture Masks to provide high-angular resolution imagery, especially suited for exoplanet imaging and characterization. This paper provides detail on the instrument's design and how it is suited to address a broad range of science cases, from detailed studies of the galactic centre at the highest resolutions, to studying detailed resolved stellar populations.

  13. VLT transit and occultation photometry for the bloated planet CoRoT-1b

    CERN Document Server

    Gillon, M; Triaud, A H M J; Barman, T; Hebb, L; Montalban, J; Maxted, P F L; Queloz, D; Deleuil, M; Magain, P

    2009-01-01

    We present VLT eclipse photometry for the giant planet CoRoT-1b. We observed a transit in the R-band filter and an occultation in a narrow filter centered on 2.09 microns. Our analysis of this new photometry and published radial velocities, in combination with stellar-evolutionary modeling, leads to a planetary mass and radius of 1.07 (+0.13,-0.18) M_Jup and 1.45 (+0.07,-0.13) R_Jup, confirming the very low density previously deduced from CoRoT photometry. The large occultation depth that we measure at 2.09 microns (0.278 (+0.043,-0.066) %) is consistent with thermal emission and is better reproduced by an atmospheric model with no redistribution of the absorbed stellar flux to the night side of the planet.

  14. Direct exoplanet detection and characterization using the ANDROMEDA method: Performance on VLT/NaCo data

    CERN Document Server

    Cantalloube, F; Mugnier, L M; Milli, J; Absil, O; Gonzalez, C A Gomez; Chauvin, G; Beuzit, J -L; Cornia, A

    2015-01-01

    Context. The direct detection of exoplanets with high-contrast imaging requires advanced data processing methods to disentangle potential planetary signals from bright quasi-static speckles. Among them, angular differential imaging (ADI) permits potential planetary signals with a known rotation rate to be separated from instrumental speckles that are either statics or slowly variable. The method presented in this paper, called ANDROMEDA for ANgular Differential OptiMal Exoplanet Detection Algorithm is based on a maximum likelihood approach to ADI and is used to estimate the position and the flux of any point source present in the field of view. Aims. In order to optimize and experimentally validate this previously proposed method, we applied ANDROMEDA to real VLT/NaCo data. In addition to its pure detection capability, we investigated the possibility of defining simple and efficient criteria for automatic point source extraction able to support the processing of large surveys. Methods. To assess the performan...

  15. The binarity status of stars with and without planets Probed with vlt/naco

    Directory of Open Access Journals (Sweden)

    S. Udry

    2004-01-01

    Full Text Available Las propiedades de los planetas en orbita alrededor de una componente de una estrella binaria o m ultiple son distintas a las de los planetas de las estrellas aisladas (Udry et al., 2004. Describimos un sondeo con la optica adaptativa VLT/NACO que intenta estudiar el efecto de la duplicidad estelar en la formaci on y evoluci on de los planetas, comparando la estad stica de las compa~neras d ebiles en muestras de estrellas con y sin planetas, seleccionadas en forma similar. Los resultados nos permitir an discriminar entre los modelos para la formaci on de planetas (acreci on o inestabilidad del disco. Los resultados preliminares son muy interesantes: el 20 7% de las estrellas \\sencillas" tienen compa~neras dentro de 1000, mientras que s olo el 3 3% de compa~neras equivalentes se encuentran cerca de las estrellas que albergan.

  16. Deep census of variable stars in a VLT/VIMOS field in Carina

    CERN Document Server

    Pietrukowicz, P; Fernández, J M; Pietrzynski, G; Ruiz, M T; Gieren, W; Diaz, R F; Zoccali, M; Hempel, M

    2009-01-01

    We have searched for variable stars in deep V-band images of a field towards the Galactic plane in Carina. The images were taken with VIMOS instrument at ESO VLT during 4 contiguous nights in April 2005. We detected 348 variables among 50897 stars in the magnitude range between V=15.4 and V=24.5 mag. Upon detection, we classified the variables by direct eye inspection of their light curves. All variable objects but 9 OGLE transits in the field are new discoveries. We provide a complete catalog of all variables which includes eclipsing/ellipsoidal binaries, miscellaneous pulsators (mostly delta Scuti-type variables), stars with flares and other (irregular and likely long-period) variables. Only two of the stars in our sample are known to host planets. Our result give some implications for future large variability surveys.

  17. Close Companions to Nearby Young Stars from Adaptive Optics Imaging on VLT and Keck

    Science.gov (United States)

    Haisch, Karl E.; Jayawardhana, Ray; Brandeker, Alexis; Mardones, Diego

    We report the results of VLT and Keck adaptive optics surveys of known members of the η Chamaeleontis, MBM 12, and TW Hydrae (TWA) associations to search for close companions. The multiplicity statistics of η Cha, MBM 12, and TWA are quite high compared with other clusters and associations, although our errors are large due to small number statistics. We have resolved S18 in MBM 12 and RECX 9 in η Cha into triples for the first time. The tight binary TWA 5Aab in the TWA offers the prospect of measuring the dynamical masses of both components as well as an independent distance to the system within a few years. The AO detection of the close companion to the nearby young star χ1 Orionis, previously inferred from radial velocity and astrometric observations, has already made it possible to derive the dynamical masses of that system without any astrophysical assumption.

  18. Close Companions to Nearby Young Stars from Adaptive Optics Imaging on VLT and Keck

    CERN Document Server

    Haisch, K E; Brandeker, A; Mardones, D; Jr., Karl E. Haisch; Jayawardhana, Ray; Brandeker, Alexis; Mardones, Diego

    2003-01-01

    We report the results of VLT and Keck adaptive optics surveys of known members of the Eta Chamaeleontis, MBM 12, and TW Hydrae (TWA) associations to search for close companions. The multiplicity statistics of Eta Cha, MBM 12, and TWA are quite high compared with other clusters and associations, although our errors are large due to small number statistics. We have resolved S18 in MBM 12 and RECX 9 in Eta Cha into triples for the first time. The tight binary TWA 5Aab in the TWA offers the prospect of measuring the dynamical masses of both components as well as an independent distance to the system within a few years. The AO detection of the close companion to the nearby young star Chi^1 Orionis, previously inferred from radial velocity and astrometric observations, has already made it possible to derive the dynamical masses of that system without any astrophysical assumption.

  19. Building Medium Size Telescope Structures for the Cherenkov Telescope Array

    CERN Document Server

    Schulz, A; Oakes, L; Schlenstedt, S; Schwanke, U

    2016-01-01

    The Cherenkov Telescope Array (CTA) is the future instrument in ground-based gamma-ray astronomy in the energy range from 20 GeV to 300 TeV. Its sensitivity will surpass that of current generation experiments by a factor $\\sim$10, facilitated by telescopes of three sizes. The performance in the core energy regime will be dominated by Medium Size Telescopes (MST) with a reflector of 12 m diameter. A full-size mechanical prototype of the telescope structure has been constructed in Berlin. The performance of the prototype is being evaluated and optimisations, among others, facilitating the assembly procedure and mass production possibilities are being implemented. We present the current status of the developments from prototyping towards pre-production telescopes, which will be deployed at the final site.

  20. The neutrino telescope ANTARES

    Directory of Open Access Journals (Sweden)

    Gleixner Andreas

    2014-04-01

    Full Text Available The ANTARES neutrino telescope is currently the largest neutrino detector in the Northern Hemisphere. The detector consists of a three-dimensional array of 885 photomultiplier tubes, distributed along 12 lines, located at a depth of 2500 m in the Mediterranean Sea. The purpose of the experiment is the detection of high-energy cosmic neutrinos. The detection principle is based on the observation of Cherenkov-Light emitted by muons resulting from charged-current interactions of muon neutrinos in the vicinity of the detection volume. The main scientific targets of ANTARES include the search for astrophysical neutrino point sources, the measurement of the diffuse neutrino flux and the indirect search for dark matter.

  1. The ANTARES neutrino telescope

    CERN Document Server

    Zornoza, Juan de Dios

    2012-01-01

    The ANTARES collaboration completed the installation of the first neutrino detector in the sea in 2008. It consists of a three dimensional array of 885 photomultipliers to gather the Cherenkov photons induced by relativistic muons produced in charged-current interactions of high energy neutrinos close to/in the detector. The scientific scope of neutrino telescopes is very broad: the origin of cosmic rays, the origin of the TeV photons observed in many astrophysical sources or the nature of dark matter. The data collected up to now have allowed us to produce a rich output of physics results, including the map of the neutrino sky of the Southern hemisphere, search for correlations with GRBs, flaring sources, gravitational waves, limits on the flux produced by dark matter self-annihilations, etc. In this paper a review of these results is presented.

  2. Composite telescope technology

    Science.gov (United States)

    Chen, Peter C.; Rabin, Douglas

    2014-07-01

    We report the development of optical mirrors based on polymer matrix composite materials. Advantages of this technology are low cost and versatility. By using appropriate combinations of polymers and various metallic and nonmetallic particles and fibers, the properties of the materials can be tailored to suit a wide variety of applications. We report the fabrication and testing of flat and curved mirrors made with metal powders, multiple mirrors replicated with high degree of uniformity from the same mandrels, cryogenic testing, mirrors made of ferromagnetic materials that can be actively or adaptively controlled by non-contact actuation, optics with very smooth surfaces made by replication, and by spincasting. We discuss development of a new generation of ultra-compact, low power active optics and 3D printing of athermal telescopes.

  3. Telescopes for the 1980s

    Science.gov (United States)

    Neugebauer, G.

    In the last decades, astronomy has been changed in a number of significant ways. The number of large optical telescopes with diameters on the order of or larger than 2.3 m has increased from 3 shortly after World War II to about 20 at the present time. Whereas prewar astronomy was largely devoted to the visual wavelengths (0.3-0.8 μm), astronomical observations currently span the range from γ ray wavelengths to the longest radio wavelengths. Most significantly, astronomy outside conventional optical astronomy has developed into sophisticated disciplines rather than experimental explorations. Many of the observational advances at the forefront of astronomy now come from other than visual observations. Along with these changes have come fundamental changes in visual astronomy itself. Observations with photographic plates are the exception rather than the rule at most large observatories. Instead, electronic cameras are in common use. A second change, especially in the United States, is that the funding has gone from largely private funding (e.g., the Carnegie Institution of Washington) to funding with the government providing a main share of the support. Indeed, the government has provided the total funding for those disciplines, like X ray astronomy, which use space-borne platforms. These changes have also affected the character of doing astronomy, and astronomers have become much more politically active on the national science scene.

  4. The next generation Cherenkov Telescope Array observatory: CTA

    CERN Document Server

    Vercellone, Stefano

    2014-01-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to the VHE gamma-ray astrophysics in the energy range 30 GeV-100 TeV, which will improve by about one order of magnitude the sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). In order to achieve such improved performance, for both the northern and southern CTA sites, four units of 23m diameter Large Size Telescopes (LSTs) will be deployed close to the centre of the array with telescopes separated by about 100m. A larger number (about 25 units) of 12m Medium Size Telescopes (MSTs, separated by about 150m), will cover a larger area. The southern site will also include up to 24 Schwarzschild-Couder dual-mirror medium-size Telescopes (SCTs) with the primary mirror diameter of 9.5m. Above a few TeV, the Cherenkov light intensity is such that showers can be detected even well outside the light pool by telescopes significantly smaller than the MSTs. To a...

  5. A novel fully differential telescopic operational transconductance amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Li Tianwang; Jiang Jinguang [Department of Integrated Circuits and Communication Software, International School of Software, Wuhan University, Wuhan 430079 (China); Ye Bo, E-mail: jgjiang95@yahoo.com.c [Faculty of Computer and Information Engineering, Shanghai University of Electric Power, Shanghai 200090 (China)

    2009-08-15

    A novel fully differential telescopic operational transconductance amplifier (OTA) is proposed. An additional PMOS differential pair is introduced to improve the unit-gain bandwidth of the telescopic amplifier. At the same time, the slew rate is enhanced by the auxiliary slew rate boost circuits. The proposed OTA is designed in a 0.18{mu}m CMOS process. Simulation results show that there is a 49% improvement in the unit-gain bandwidth compared to that of a conventional OTA; moreover, the DC gain and the slew rate are also enhanced. (semiconductor integrated circuits)

  6. Infrared up-conversion telescope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented to an up-conversion infrared telescope (110) arranged for imaging an associated scene (130), wherein the up-conversion infrared telescope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein a first optical...

  7. European Solar Telescope: Progress status

    NARCIS (Netherlands)

    Collados, M.; Bettonvil, F.C.M.; Cavaller, L.; Ermolli, I.; Gelly, B.; Pérez, A.; Socas-Navarro, H.; Soltau, D.; Volkmer, R.

    2010-01-01

    In this paper, the present status of the development of the design of the European Solar Telescope is described. The telescope is devised to have the best possible angular resolution and polarimetric performance, maximizing the throughput of the whole system. To that aim, adaptive optics and multi-c

  8. XQ-100: A legacy survey of one hundred 3.5 ≲ z ≲ 4.5 quasars observed with VLT/X-shooter

    Science.gov (United States)

    López, S.; D'Odorico, V.; Ellison, S. L.; Becker, G. D.; Christensen, L.; Cupani, G.; Denney, K. D.; Pâris, I.; Worseck, G.; Berg, T. A. M.; Cristiani, S.; Dessauges-Zavadsky, M.; Haehnelt, M.; Hamann, F.; Hennawi, J.; Iršič, V.; Kim, T.-S.; López, P.; Lund Saust, R.; Ménard, B.; Perrotta, S.; Prochaska, J. X.; Sánchez-Ramírez, R.; Vestergaard, M.; Viel, M.; Wisotzki, L.

    2016-10-01

    We describe the execution and data reduction of the European Southern Observatory Large Programme "Quasars and their absorption lines: a legacy survey of the high-redshift Universe with VLT/X-shooter" (hereafter "XQ-100"). XQ-100 has produced and made publicly available a homogeneous and high-quality sample of echelle spectra of 100 quasars (QSOs) at redshifts z ≃ 3.5-4.5 observed with full spectral coverage from 315 to 2500 nm at a resolving power ranging from R ~ 4000 to 7000, depending on wavelength. The median signal-to-noise ratios are 33, 25 and 43, as measured at rest-frame wavelengths 1700, 3000 and 3600 Å, respectively. This paper provides future users of XQ-100 data with the basic statistics of the survey, along with details of target selection, data acquisition and data reduction. The paper accompanies the public release of all data products, including 100 reduced spectra. XQ-100 is the largest spectroscopic survey to date of high-redshift QSOs with simultaneous rest-frame UV/optical coverage, and as such enables a wide range of extragalactic research, from cosmology and galaxy evolution to AGN astrophysics. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 189.A-0424.The XQ-100 raw data and the XQ-100 Science Data Products can be found at http://archive.eso.org/eso/eso_archive_main.html and http://archive.eso.org/wdb/wdb/adp/phase3_main/form, respectively.

  9. Seismic Imager Space Telescope

    Science.gov (United States)

    Sidick, Erkin; Coste, Keith; Cunningham, J.; Sievers,Michael W.; Agnes, Gregory S.; Polanco, Otto R.; Green, Joseph J.; Cameron, Bruce A.; Redding, David C.; Avouac, Jean Philippe; Ampuero, Jean Paul; Leprince, Sebastien; Michel, Remi

    2012-01-01

    A concept has been developed for a geostationary seismic imager (GSI), a space telescope in geostationary orbit above the Pacific coast of the Americas that would provide movies of many large earthquakes occurring in the area from Southern Chile to Southern Alaska. The GSI movies would cover a field of view as long as 300 km, at a spatial resolution of 3 to 15 m and a temporal resolution of 1 to 2 Hz, which is sufficient for accurate measurement of surface displacements and photometric changes induced by seismic waves. Computer processing of the movie images would exploit these dynamic changes to accurately measure the rapidly evolving surface waves and surface ruptures as they happen. These measurements would provide key information to advance the understanding of the mechanisms governing earthquake ruptures, and the propagation and arrest of damaging seismic waves. GSI operational strategy is to react to earthquakes detected by ground seismometers, slewing the satellite to point at the epicenters of earthquakes above a certain magnitude. Some of these earthquakes will be foreshocks of larger earthquakes; these will be observed, as the spacecraft would have been pointed in the right direction. This strategy was tested against the historical record for the Pacific coast of the Americas, from 1973 until the present. Based on the seismicity recorded during this time period, a GSI mission with a lifetime of 10 years could have been in position to observe at least 13 (22 on average) earthquakes of magnitude larger than 6, and at least one (2 on average) earthquake of magnitude larger than 7. A GSI would provide data unprecedented in its extent and temporal and spatial resolution. It would provide this data for some of the world's most seismically active regions, and do so better and at a lower cost than could be done with ground-based instrumentation. A GSI would revolutionize the understanding of earthquake dynamics, perhaps leading ultimately to effective warning

  10. High-redshift supernova rates measured with the gravitational telescope A 1689

    Science.gov (United States)

    Petrushevska, T.; Amanullah, R.; Goobar, A.; Fabbro, S.; Johansson, J.; Kjellsson, T.; Lidman, C.; Paech, K.; Richard, J.; Dahle, H.; Ferretti, R.; Kneib, J. P.; Limousin, M.; Nordin, J.; Stanishev, V.

    2016-10-01

    Aims: We present a ground-based, near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z = 0.18, which is one of the most powerful gravitational telescopes that nature provides. Methods: Our survey was based on multi-epoch J-band observations with the HAWK-I instrument on VLT, with supporting optical data from the Nordic Optical Telescope. Results: Our search resulted in the discovery of five photometrically classified, core-collapse supernovae with high redshifts of 0.671 formula>math id="mml_eq2" type="inline">10-12 SNe L⊙,B-1 yr-1math>formula->), where the error bars indicate 1σ confidence intervals, statistical and systematic, respectively. The cluster rate normalized by the stellar mass is 0.10+0.13-0.096±0.02 in SNuM h2 (SNuM ≡10-12SNe M-1⊙ yr-1). Furthermore, we explore the optimal future survey for improving the core-collapse supernova rate measurements at z ≳ 2 using gravitational telescopes, and for detections with multiply lensed images, and we find that the planned WFIRST space mission has excellent prospects. Conclusions: Massive clusters can be used as gravitational telescopes to significantly expand the survey range of supernova searches, with important implications for the study of the high-z transient Universe. Based on observations made with European Southern Observatory (ESO) telescopes at the Paranal Observatory under programme ID 082.A-0431; 0.83.A-0398, 091.A-0108 and ID 093.A-0278, PI: A. Goobar.The deep average image (FITS file) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/594/A54

  11. Operating a heterogeneous telescope network

    Science.gov (United States)

    Allan, Alasdair; Bischoff, Karsten; Burgdorf, Martin; Cavanagh, Brad; Christian, Damien; Clay, Neil; Dickens, Rob; Economou, Frossie; Fadavi, Mehri; Frazer, Stephen; Granzer, Thomas; Grosvenor, Sandy; Hessman, Frederic V.; Jenness, Tim; Koratkar, Anuradha; Lehner, Matthew; Mottram, Chris; Naylor, Tim; Saunders, Eric S.; Solomos, Nikolaos; Steele, Iain A.; Tuparev, Georg; Vestrand, W. Thomas; White, Robert R.; Yost, Sarah

    2006-06-01

    In the last few years the ubiquitous availability of high bandwidth networks has changed the way both robotic and non-robotic telescopes operate, with single isolated telescopes being integrated into expanding "smart" telescope networks that can span continents and respond to transient events in seconds. The Heterogeneous Telescope Networks (HTN)* Consortium represents a number of major research groups in the field of robotic telescopes, and together we are proposing a standards based approach to providing interoperability between the existing proprietary telescope networks. We further propose standards for interoperability, and integration with, the emerging Virtual Observatory. We present the results of the first interoperability meeting held last year and discuss the protocol and transport standards agreed at the meeting, which deals with the complex issue of how to optimally schedule observations on geographically distributed resources. We discuss a free market approach to this scheduling problem, which must initially be based on ad-hoc agreements between the participants in the network, but which may eventually expand into a electronic market for the exchange of telescope time.

  12. Why systems engineering on telescopes?

    Science.gov (United States)

    Swart, Gerhard P.; Meiring, Jacobus G.

    2003-02-01

    Although Systems Engineering has been widely applied to the defence industry, many other projects are unaware of its potential benefits when correctly applied, assuming that it is an expensive luxury. It seems that except in a few instances, telescope projects are no exception, prompting the writing of this paper. The authors postulate that classical Systems Engineering can and should be tailored, and then applied to telescope projects, leading to cost, schedule and technical benefits. This paper explores the essence of Systems Engineering and how it can be applied to any complex development project. The authors cite real-world Systems Engineering examples from the Southern African Large Telescope (SALT). The SALT project is the development and construction of a 10m-class telescope at the price of a 4m telescope. Although SALT resembles the groundbreaking Hobby-Eberly Telescope (HET) in Texas, the project team are attempting several challenging changes to the original design, requiring a focussed engineering approach and discernment in the definition of the telescope requirements. Following a tailored Systems Engineering approach on this project has already enhanced the quality of decisions made, improved the fidelity of contractual specifications for subsystems, and established criteria testing their performance. Systems Engineering, as applied on SALT, is a structured development process, where requirements are formally defined before the award of subsystem developmental contracts. During this process conceptual design, modeling and prototyping are performed to ensure that the requirements were realistic and accurate. Design reviews are held where the designs are checked for compliance with the requirements. Supplier factory and on-site testing are followed by integrated telescope testing, to verify system performance against the specifications. Although the SALT project is still far from completion, the authors are confident that the present benefits from

  13. Skylab Apollo Telescope Mount Spar and Sun End

    Science.gov (United States)

    1971-01-01

    The Apollo Telescope Mount (ATM) was designed and developed by the Marshall Space Flight Center and served as the primary scientific instrument unit aboard Skylab (1973-1979). The ATM contained eight complex astronomical instruments designed to observe the Sun over a wide spectrum from visible light to x-rays. This image depicts the sun end and spar of the ATM flight unit showing individual telescopes. All solar telescopes, the fine Sun sensors, and some auxiliary systems are mounted on the spar, a cruciform lightweight perforated metal mounting panel that divides the canister lengthwise into four equal compartments. The spar assembly was nested inside a cylindrical canister that fit into a complex frame named the rack, and was protected by the solar shield.

  14. Formation flight astronomical survey telescope

    Science.gov (United States)

    Tsunemi, Hiroshi

    2012-03-01

    Formation Flight Astronomical Survey Telescope (FFAST) is a project for hard X-ray observation. It consists of two small satellites; one (telescope satellite) has a super mirror covering the energy range up to 80 keV while the other (detector satellite) has an scintillator deposited CCD (SDCCD) having good spatial resolution and high efficiency up to 100 keV. Two satellites will be put into individual Kepler orbits forming an X-ray telescope with a focal length of 20 m. They will be not in pointing mode but in survey mode to cover a large sky region.

  15. The Automatic Telescope Network (ATN)

    CERN Document Server

    Mattox, J R

    1999-01-01

    Because of the scheduled GLAST mission by NASA, there is strong scientific justification for preparation for very extensive blazar monitoring in the optical bands to exploit the opportunity to learn about blazars through the correlation of variability of the gamma-ray flux with flux at lower frequencies. Current optical facilities do not provide the required capability.Developments in technology have enabled astronomers to readily deploy automatic telescopes. The effort to create an Automatic Telescope Network (ATN) for blazar monitoring in the GLAST era is described. Other scientific applications of the networks of automatic telescopes are discussed. The potential of the ATN for science education is also discussed.

  16. Bhavnagar Telescope: the most widely travelled telescope in the country

    CERN Document Server

    Rao, N Kameswara; Vagiswari, A

    2014-01-01

    In the last decade of the 19th century Maharaja Takhtasingji Observatory was built at Poona (1888-1912) under the supervision of K.D.Naegamavala, with the grant from Maharaja of Bhavnagar (from where the name Bhavnagar Telescope must have originated. The story of this telescope from its inception to the current status is traced. IIA Archives has been extensively used to resource information for this note.

  17. Ice Middleware in the New Solar Telescope's Telescope Control System

    Science.gov (United States)

    Shumko, S.

    2009-09-01

    The Big Bear Solar Observatory (BBSO) is now in the process of assembling and aligning its 1.6 m New Solar Telescope (NST). There are many challenges controlling NST and one of them is establishing reliable and robust communications between different parts of the Telescope Control System (TCS). For our TCS we selected Ice (Internet communication engine) from ZeroC, Inc. In this paper we discuss advantages of the Ice middleware, details of implementation and problems we face implementing it.

  18. The small size telescope projects for the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    The small size telescopes (SSTs), spread over an area of several square km, dominate the CTA sensitivity in the photon energy range from a few TeV to over 100 TeV, enabling for the detailed exploration of the very high energy gamma-ray sky. The proposed telescopes are innovative designs providing a wide field of view. Two of them, the ASTRI (Astrophysics con Specchi a Tecnologia Replicante Italiana) and the GCT (Gamma-ray Cherenkov Telescope) telescopes, are based on dual mirror Schwarzschild-Couder optics, with primary mirror diameters of 4 m. The third, SST-1M, is a Davies-Cotton design with a 4 m diameter mirror. Progress with the construction and testing of prototypes of these telescopes is presented. The SST cameras use silicon photomultipliers, with preamplifier and readout/trigger electronics designed to optimize the performance of these sensors for (atmospheric) Cherenkov light. The status of the camera developments is discussed. The SST sub-array will consist of about 70 telescopes at the CTA souther...

  19. Lightweighted ZERODUR for telescopes

    Science.gov (United States)

    Westerhoff, T.; Davis, M.; Hartmann, P.; Hull, T.; Jedamzik, R.

    2014-07-01

    The glass ceramic ZERODUR® from SCHOTT has an excellent reputation as mirror blank material for earthbound and space telescope applications. It is known for its extremely low coefficient of thermal expansion (CTE) at room temperature and its excellent CTE homogeneity. Recent improvements in CNC machining at SCHOTT allow achieving extremely light weighted substrates up to 90% incorporating very thin ribs and face sheets. In 2012 new ZERODUR® grades EXPANSION CLASS 0 SPECIAL and EXTREME have been released that offer the tightest CTE grades ever. With ZERODUR® TAILORED it is even possible to offer ZERODUR® optimized for customer application temperature profiles. In 2013 SCHOTT started the development of a new dilatometer setup with the target to drive the industrial standard of high accuracy thermal expansion metrology to its limit. In recent years SCHOTT published several paper on improved bending strength of ZERODUR® and lifetime evaluation based on threshold values derived from 3 parameter Weibull distribution fitted to a multitude of stress data. ZERODUR® has been and is still being successfully used as mirror substrates for a large number of space missions. ZERODUR® was used for the secondary mirror in HST and for the Wolter mirrors in CHANDRA without any reported degradation of the optical image quality during the lifetime of the missions. Some years ago early studies on the compaction effects of electron radiation on ZERODUR® were re analyzed. Using a more relevant physical model based on a simplified bimetallic equation the expected deformation of samples exposed in laboratory and space could be predicted in a much more accurate way. The relevant ingredients for light weighted mirror substrates are discussed in this paper: substrate material with excellent homogeneity in its properties, sufficient bending strengths, space radiation hardness and CNC machining capabilities.

  20. Telescopic drilling rod

    Energy Technology Data Exchange (ETDEWEB)

    Kagan, I.L.; Berezov, S.I.; Gavrilov, G.A.; Goykhman, Ya.A.; Makushkin, D.O.; Rachev, M.P.; Voynich, L.K.

    1981-09-07

    The telescopic drilling rod includes an inner section of the rod, in whose center cable has been passed and is attached a bearing assembly connecting it to the winch, outer section of rod along which there is pipeline connecting the working cavity formed by the inner section of rod and the housing, installed on the lower end of the outer section of rod, with cavity formed by framework of the guide swivel and end piece and connected to the hydraulic system of the machine by pipeline, as well as clamping elements. In order to drill wells to a depth greater than the length of the outer sectrion of the rod, the latter jointly with the inner section of rod is lowered into the extreme lower position until swivel rests on the feed mechanism. With further slipping of cable and the absence of pressure in the hydraulic system, clamping elements do not have an effect on the inner section of rod. It has the opportunity to freely move along the outer section of rod downwards to the face. When pressure is supplied on pipeline into cavity and further through pipeline into working cavity, the inner section of rod is clamped with feed of the outer section in the process of drilling, both sections move jointly. Because of the link between working cavity of sleeve installed on the lower end of the outer section of rod, and the hydraulic system of the machine through the swivel cavity, it is possible to fix the drilling rod in any mutual axial position of the section.

  1. BCK Network of Optical Telescopes

    Science.gov (United States)

    McGruder, Charles H.; Antoniuk, Krill; Carini, Michael T.; Gelderman, Richard; Hammond, Benjamin; Hicks, Stacy; Laney, David; Shakhovskoy, David; Strolger, Louis-Gregory; Williams, Joshua

    2015-01-01

    The BCK network consists of three research grade telescopes: 0.6m (B) at the Bell Observatory near Western Kentucky University (WKU), 1.3m (C) at the Crimean Astrophysical Observatory and a 1.3m (K) at Kitt Peak National Observatory. The Bell Telescope is operated remotely from WKU while the Robotically Controlled Telescope (RCT) at Kitt Peak possesses an autonomous scheduler. The BCK telescopes are distributed longitudinally over 145º and can be used to observe continuously up to 21.2 hours/day. The network will be chiefly employed to observe variable stars, blazars and unpredictable celestial events.Because celestial objects with ground-based telescopes cannot be observed optically during the daytime, continuous ground-based astronomical observations are only possible via a network of longitudinally distributed telescopes. When the sun rises in Crimea after it sets at Bell, continuous observations are possible. This occurs for about six and ½ months per year - mid September to early April. A network is highly desirable for events that are not predictable for instance the appearance of supernovae, gamma-ray bursts, or undiscovered exoplanetsVariable stars are really only known in significant numbers to about 14 mag. But, as the magnitude increases the number of stars in any field increases very sharply, so there are many variable stars to discover at faint magnitude (m > 14). Discovering new variables makes great undergraduate student projects, a major component of astronomical research at WKU. In addition, pinning down the periods of variable stars is greatly facilitated with a network of telescopes.The BCK telescope network will also be used for monitoring the optical variability of blazars. The network provides increased coverage on daily variability timescales by minimizing interruptions due to weather and or mechanical problems at any one observatory and is used for obtaining continuous (12+ hours) of observations of rapid variability in blazars which would

  2. Hubble Space Telescope-Illustration

    Science.gov (United States)

    1989-01-01

    This illustration depicts a side view of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  3. The Large Binocular Telescope Project

    Science.gov (United States)

    Hill, J. M.

    1995-05-01

    The Large Binocular Telescope (LBT) Project has evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 x 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astrofisico di Arcetri and the Research Corporation based in Tucson. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train --- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in spring of 1996 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximicrons flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximicrons stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1995 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson) and ADS Italia

  4. The calculus of telescopic urbanism

    OpenAIRE

    Arabindoo, P.

    2013-01-01

    Developing Amin's invocation of a telescopic urbanism as more than a visual metaphor, this paper seeks to rethink its epistemological and methodological focus, resisting at the same time the tendency to oversimplify the relationship between the different optics he outlines. Threatened by a dominant meta-narrative of a numerically driven calculus, this paper identifies an opportunity in Amin's telescopic urbanism to reject the 'big-data' approach to the city. In this context, it challenges the...

  5. The ASTRI prototype and mini-array: precursor telescopes for the Cherenkov Telescope Array

    Science.gov (United States)

    Pareschi, Giovanni

    2016-07-01

    In the framework of the Cherenkov Telescope Array (CTA) Observatory, the Italian National Institute of Astrophysics (INAF) has recently inaugurated in Sicily (Italy), at the Serra La Nave astronomical site on the slopes of Mount Etna, a large field of view (9.6 degrees) dual-mirror prototype (ASTRI SST-2M) of the CTA small size class of telescopes. CTA plans to install about 70 small size telescopes in the southern site to allow the study of the gamma rays from a few TeV up to hundreds of TeV. The ASTRI SST-2M telescope prototype has been developed following an end-to-end approach, since it includes the entire system of structure, mirror's optics (primary and secondary mirrors), camera, and control/acquisition software. Although it is a technological prototype, the ASTRI SST-2M prototype will be able to perform systematic monitoring of bright TeV sources. A remarkable improvement in terms of performance could come from the operation of the ASTRI mini-array, led by INAF in synergy with the Universidade de Sao Paulo (Brazil) and the North-West University (South Africa) and with also a contribution by INFN. The ASTRI mini-array will be composed of at least nine ASTRI SST-2M units. It is proposed as one of the CTA mini-array of telescope precursors and initial seeds of CTA, to be installed at the final CTA southern site. Apart from the assessment of a number of technological aspects related to CTA, the ASTRI mini-array will extend and improve the sensitivity, similar to the H.E.S.S. one in the 1-10 TeV energy range, up to about 100 TeV.

  6. Demonstration Telescopes Using "Dollar Optics"

    Science.gov (United States)

    Ross, Paul

    2008-05-01

    I propose a poster that illustrates the use of "dollar optics” for experimentation and for the creation of demonstration telescopes. Handling a variety of lenses and mirrors provides an opportunity for discovering practical optics. Some part of this path of exploration must have been traveled by Galileo as he experimented with spectacle lenses. "Dollar optics” include reading glasses (positive meniscus lenses), convex and concave mirrors, Fresnel sheets, magnifying lenses, and eye loupes. Unwanted distance spectacles (negative meniscus lenses) are available at second-hand stores. Galileo telescopes, "long” 17th century telescopes, and useful demonstration models of Newtonian reflectors can be made with "dollar” optics. The poster will illustrate practical information about "dollar optics” and telescopes: magnification, focal length, and "diopters” disassembling spectacles; creating cheap mounts for spectacle lenses; the importance of optical axes and alignment; eyepieces; and focusing. (A table would be useful with the poster to set out a hands-on display of "dollar optic” telescopes.) Educators, experimenters, and those concerned with astronomy outreach might be interested in this poster. Working with "dollar optics” requires facility with simple tools, interest in planning projects, patience, imagination, and the willingness to invest some time and effort. "Dollar optics” may help to foster creativity and hands-on enthusiasm - as did Galileo's work with simple lenses 400 years ago. "Oh! When will there be an end put to the new observations and discoveries of this admirable instrument?” - Galileo Galilei as quoted by Henry C. King, The History of the Telescope.

  7. The upgraded MAGIC Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Tescaro, D., E-mail: dtescaro@iac.es [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Universidad de La Laguna (ULL), Dept. Astrofísica, E-38206 La Laguna, Tenerife (Spain)

    2014-12-01

    The MAGIC Cherenkov telescopes underwent a major upgrade in 2011 and 2012. A new 1039-pixel camera and a larger area digital trigger system were installed in MAGIC-I, making it essentially identical to the newer MAGIC-II telescope. The readout systems of both telescopes were also upgraded, with fully programmable receiver boards and DRS4-chip-based digitization systems. The upgrade eased the operation and maintenance of the telescopes and also improved significantly their performance. The system has now an integral sensitivity as good as 0.6% of the Crab Nebula flux (for E>400GeV), with an effective analysis threshold at 70 GeV. This allows MAGIC to secure one of the leading roles among the current major ground-based Imaging Atmospheric Cherenkov telescopes for the next 5–10 years. - Highlights: • In 2011 and 2012 the MAGIC telescopes underwent a two-stage major upgrade. • The new camera of MAGIC-I allows us to exploit a 1.4 larger trigger area. • The novel DRS4-based readout systems allow a cost-effective ultra-fast digitization. • The upgrade greatly improved the maintainability of the system. • MAGIC has now an optimal integral sensitivity of 0.6% of the Crab Nebula flux.

  8. SLAS Library Telescope Program (Abstract)

    Science.gov (United States)

    Small, J. S.

    2016-12-01

    (Abstract only) In the fall of 2014, I submitted to the members of the St. Louis Astronomical Society to take the $1,000 profit we had from a convention we had hosted and use it to purchase three telescopes to modify for a Library Telescope program that was invented by Mark Stowbridge and promoted by the New Hampshire Astronomical Society. I had met Mark at NEAF in 2012 when he was walking the floor demonstrating the telescope. We held meetings with three libraries, the St. Louis County Library system, the St. Louis Public Library system and an independent library in Kirkwood, Missouri. The response was overwhelming! SLCL responded with a request for ten telescopes and SLPL asked for five. We did our first build in October, 2014 and placed a total of eighteen telescopes. Since that time, SLAS has placed a total of eighty-eight telescopes in library systems around the St. Louis Metro area, expanding into neighboring counties and across the river in Illinois. In this talk, I will discuss how to approach this project and put it in place in your libraries!

  9. Concept Design for SOAR Telescope

    Science.gov (United States)

    Sebring, T.; Cecil, G.; Krabbendam, V.; Moretto, G.

    1998-12-01

    The Southern Astrophysical Research (SOAR) telescope is a \\$28M collaboration between Brazil, NOAO, Michigan State University, and the University of North Carolina at Chapel Hill. NOAO will operate the telescope for 20 years in exchange for 30 astronomers.) The project is now fully funded. This f/16 telescope is optimized for high-quality images across the isokinetic field (0."17 FWHM degradation from the telescope+facility over a field of 7.5' diameter.) It is being designed to take up to 2 Gemini-class (2100 kg) instruments, or a combination of lighter instruments at 7 Nasmyth and bent Cassegrain foci. The facility is now under construction atop Cerro Pachon, 400m from Gemini-S. First light is currently scheduled for early 2002. Corning Inc. is preparing to fabricate the 4.2m-diameter, 7.5-10 cm thick primary mirror from ULE glass. In early 1999 contacts will be awarded for 2 major subsystems: active optics (which includes optics polishing), and the alt.-az. telescope mount. We will outline the novel strategies that are being used to control project costs while optimizing telescope performance. Instrumentation plans will also be summarized.

  10. Cryogenic optical test planning using the Optical Telescope Element Simulator with the James Webb Space Telescope Integrated Science Instrument Module

    Science.gov (United States)

    Reichard, Timothy A.; Bond, Nicholas A.; Greeley, Bradford W.; Malumuth, Eliot M.; Melendez, Marcio; Shiri, Ron; Alves de Oliveira, Catarina; Antonille, Scott R.; Birkmann, Stephan; Davis, Clinton; Dixon, William V.; Martel, André R.; Miskey, Cherie L.; Ohl, Raymond G.; Sabatke, Derek; Sullivan, Joseph

    2016-09-01

    NASA's James Webb Space Telescope (JWST) is a 6.5 m diameter, segmented, deployable telescope for cryogenic infrared space astronomy ( 40 K). The JWST Observatory architecture includes the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM) element that contains four science instruments (SIs), including a guider. The SI and guider units are integrated to the ISIM structure and optically tested at NASA Goddard Space Flight Center as an instrument suite using a telescope simulator (Optical Telescope Element SIMulator; OSIM). OSIM is a high-fidelity, cryogenic JWST telescope simulator that features a 1.5m diameter powered mirror. The SIs are aligned to the flight structure's coordinate system under ambient, clean room conditions using optomechanical metrology and customized interfaces. OSIM is aligned to the ISIM mechanical coordinate system at the cryogenic operating temperature via internal mechanisms and feedback from alignment sensors and metrology in six degrees of freedom. SI performance, including focus, pupil shear, pupil roll, boresight, wavefront error, and image quality, is evaluated at the operating temperature using OSIM. The comprehensive optical test plans include drafting OSIM source configurations for thousands of exposures ahead of the start of a cryogenic test campaign. We describe how we predicted the performance of OSIM light sources illuminating the ISIM detectors to aide in drafting these optical tests before a test campaign began. We also discuss the actual challenges and successes of those exposure predictions encountered during a test campaign to fulfill the demands of the ISIM optical performance verification.

  11. VLT/FLAMES spectroscopy of Red Giant Branch stars in the Carina dwarf spheroidal galaxy

    CERN Document Server

    Lemasle, B; Tolstoy, E; Venn, K A; Shetrone, M D; Irwin, M J; de Boer, T J L; Starkenburg, E; Salvadori, S

    2011-01-01

    The ages of individual Red Giant Branch stars (RGB) can range from 1 Gyr old to the age of the Universe, and it is believed that the abundances of most chemical elements in their photospheres remain unchanged with time (those that are not affected by the 1st dredge-up). This means that they trace the ISM in the galaxy at the time the star formed, and hence the chemical enrichment history of the galaxy. CMD analysis has shown the Carina dwarf spheroidal (dSph) to have had an unusually episodic star formation history (SFH) which is expected to be reflected in the abundances of different chemical elements. We use the VLT-FLAMES spectrograph in HR mode (R~20000) to measure the abundances of several chemical elements in a sample of 35 RGB stars in Carina. We also combine these abundances with photometry to derive age estimates for these stars. This allows us to determine which of two distinct star formation (SF) episodes the stars in our sample belong to, and thus to define the relationship between SF and chemical...

  12. The VLT LBG Redshift Survey - IV. Gas and galaxies at z~3 in observations and simulations

    CERN Document Server

    Tummuangpak, P; Bielby, R; Crighton, N H M; Francke, H; Infante, L; Theuns, T

    2013-01-01

    We use observations and simulations to study the relationship between star-forming galaxies and the IGM at z~3. We use redshift data taken from the VLT LBG Redshift Survey (VLRS) and Keck surveys in fields centred on bright background QSOs, whilst the simulated data is taken from GIMIC. In the simulations, we find that the dominant peculiar velocities are in the form of large-scale coherent motions of gas and galaxies. Gravitational infall of galaxies towards each other is also seen, consistent with linear theory. Peculiar velocity pairs with separations smaller than 1Mpc have a smaller dispersion and better explain the simulated z-space correlations. Lyman-alpha auto- and cross-correlations in the simulations appear to show smaller infall than implied by the expected beta_Lyman-alpha ~ 1.3. Galaxy-wide outflows implemented in the simulations may contribute to this effect. When velocity errors are taken into account, the LBG correlation function prefers the high clustering amplitude shown by higher mass galax...

  13. The VLT LBG Redshift Survey - V. Characterising the z = 3.1 Lyman Alpha Emitter Population

    CERN Document Server

    Bielby, R M; Shanks, T; Francke, H; Crighton, N H M; Bañados, E; González-López, Jorge; Infante, L; Orsi, A

    2016-01-01

    We present a survey of Ly$\\alpha$ emitting galaxies in the fields of the VLT LBG Redshift Survey, incorporating the analysis of narrow band number counts, the rest frame UV luminosity function and the two-point correlation function of Ly$\\alpha$ emitters at $z\\approx3.1$. Our photometric sample consists of 750 LAE candidates, over an area of 1.07 deg$^2$, with estimated equivalent widths of $\\gtrsim65$ \\AA, from 5 fields based on deep Subaru Suprime-Cam imaging data. Added to this we have obtained spectroscopic follow-up observations, which successfully detected Ly$\\alpha$ emission in 35 galaxies. Based on the spectroscopic results, we refined our photometric selection constraints, with the resulting sample having a success rate of $78\\pm18\\%$. We calculate the narrow band number counts for our photometric sample and find these to be consistent with previous studies of LAEs at this redshift. We find the $R$-band continuum luminosity function to be $\\sim10\\times$ lower than the equivalent luminosity function o...

  14. Discovery of a z = 6.17 galaxy from CFHT and VLT observations

    CERN Document Server

    Cuby, J G; McCracken, H; Cuillandre, J C; Magnier, E; Meneux, B

    2003-01-01

    We report the discovery of a galaxy at a redshift z = 6.17 identified from deep narrow band imaging and spectroscopic follow-up in one of the CFHT-VIRMOS deep survey fields at 0226-04. In addition to the existing deep BVRI images of this field, we obtained a very deep narrow band image at 920 nm with the aim of detecting Ly alpha emission at redshift ~ 6.5. Spectroscopic follow-up of some of the candidates selected on the basis of their excess flux in the NB920 filter was performed at the VLT-UT4 with the FORS2 instrument. For one object a strong and asymmetric emission line associated with a strong break in continuum emission is identified as Ly alpha at z = 6.17. This galaxy was selected from its continuum emission in the 920 nm filter rather than for its Ly alpha emission, in effect performing a Lyman Break detection at z = 6.17. We estimate a star formation rate of ~ 10 M/yr for this object, with a velocity dispersion \\~ 400 km/s. Similarly to other objects at redshifts ~ 5--6, this galaxy presents the ch...

  15. VLT/FLAMES spectroscopy of red giant branch stars in the Fornax dwarf spheroidal galaxy

    CERN Document Server

    Lemasle, B; Hill, V; Tolstoy, E; Irwin, M; Jablonka, P; Venn, K; Battaglia, G; Starkenburg, E; Shetrone, M; Letarte, B; Francois, P; Helmi, A; Primas, F; Kaufer, A; Szeifert, T

    2014-01-01

    Fornax is one of the most massive dwarf spheroidal galaxies in the Local Group. The Fornax field star population is dominated by intermediate age stars but star formation was going on over almost its entire history. It has been proposed that Fornax experienced a minor merger event. Despite recent progress, only the high metallicity end of Fornax field stars ([Fe/H]>-1.2 dex) has been sampled in larger number via high resolution spectroscopy. We want to better understand the full chemical evolution of this galaxy by better sampling the whole metallicity range, including more metal poor stars. We use the VLT-FLAMES multi-fibre spectrograph in high-resolution mode to determine the abundances of several alpha, iron-peak and neutron-capture elements in a sample of 47 individual Red Giant Branch stars in the Fornax dwarf spheroidal galaxy. We combine these abundances with accurate age estimates derived from the age probability distribution from the colour-magnitude diagram of Fornax. Similar to other dwarf spheroid...

  16. VLT\\/UVES Abundances in Four Nearby Dwarf Spheroidal Galaxies I. Nucleosynthesis and Abundance Ratios

    CERN Document Server

    Shetrone, M; Tolstoy, E; Primas, F; Hill, V; Kaufer, A

    2003-01-01

    We have used UVES on VLT-UT2 to take spectra of 15 red giants in the Sculptor, Fornax, Carina and Leo I dwarf spheroidal galaxies. We measure the abundances of alpha, iron peak, s and r-process elements. No dSph giants in our sample show the deep mixing abundance pattern seen in nearly all globular clusters. At a given metallicity, the dSph giants exhibit lower [el/Fe] abundance ratios for the alpha elements than stars in the Galactic halo. This can be caused by a slow star formation rate and contribution from Type Ia SN, and/or a small star formation event (low total mass) and mass dependent Type II SN yields. Differences in the even-Z [el/Fe] ratios between these galaxies, as well as differences in the evolution of the s&r-process elements are interpreted in terms of their star formation histories. Comparison of the dSph abundances with those of the Galactic halo reveals some consistencies. In particular, we find stars that mimic the abundance pattern found by Nissen & Shuster (1997) for metal-rich,...

  17. VLT/MUSE discovers a jet from the evolved B[e] star MWC 137

    CERN Document Server

    Mehner, A; Groh, J H; Oudmaijer, R D; Baade, D; Rivinius, T; Selman, F; Boffin, H M J; Martayan, C

    2016-01-01

    Not all stars exhibiting the optical spectral characteristics of B[e] stars share the same evolutionary stage. The Galactic B[e] star MWC 137 is a prime example of an object with uncertain classification, with previous work suggesting pre- and post-main sequence classification. Our goal is to settle this debate and provide reliable evolutionary classification. Integral field spectrograph observations with VLT MUSE of the cluster SH 2-266 are used to analyze the nature of MWC 137. A collimated outflow is discovered that is geometrically centered on MWC 137. The central position of MWC 137 in the cluster SH 2-266 within the larger nebula suggests strongly that it is a member of this cluster and that it is both at the origin of the nebula and the newly discovered jet. Comparison of the color-magnitude diagram of the brightest cluster stars with stellar evolutionary models results in a distance of about 5.2$\\pm$1.4 kpc. We estimate that the cluster is at least 3 Myr old. The jet extends over 66" (1.7 pc) projecte...

  18. VLT Phase Resolved Optical Spectroscopy of the Ultra-Compact Binary HM Cnc

    CERN Document Server

    Mason, Elena; Dall'Osso, S; Stella, L; Munari, U; Marconi, G; O'Brian, K; Covino, S; Fugazza, D

    2010-01-01

    A 321.5 s modulation was discovered in 1999 in the X-ray light curve of HM Cnc. In 2001 and 2002, optical photometric and spectroscopic observations revealed that HM Cnc is a very blue object with no intrinsic absorptions but broad (FWHM 1500 km s^-1) low equivalent width emission lines (EW 1-6A), which were first identified with the HeII Pickering series. The combination of X-ray and optical observations pictures HM Cnc as a double degenerate binary hosting two white dwarfs, and possibly being the shortest orbital period binary discovered so far. The present work is aimed at studying the orbital motion of the two components by following the variations of the shape, centroid and intensity of the emission lines through the orbit. In February 2007, we carried out the first phase resolved optical spectroscopic study with the VLT/FORS2 in the High Time Resolution (HIT) mode, yielding five phase bins in the 321 s modulation. Despite the low SNR, the data show that the intensity of the three most prominent emission...

  19. VLT Observations of Turnoff stars in the Globular Cluster NGC 6397

    CERN Document Server

    Thévenin, F; De Pacheco, J A F; Idiart, T P; Jasniewicz, G; De Laverny, P; Plez, B

    2001-01-01

    VLT-UVES high resolution spectra of seven turnoff stars in the metal-poor globular cluster NGC 6397 have been obtained. Atmospheric parameters and abundances of several elements (Li, Na, Mg, Ca, Sc, Ti, Cr, Fe, Ni, Zn and Ba) were derived for program stars. The mean iron abundance is [Fe/H] = -2.02, with no star-to-star variation. The mean abundances of the alpha-elements (Ca, Ti) and of the iron-peak elements (Sc, Cr, Ni) are consistent with abundances derived for field stars of similar metallicity. Magnesium is also almost solar, consistent with the values found by Idiart & Th\\'evenin (2000) when non-LTE effects (NLTE hereafter) are taken into account. The sodium abundance derived for five stars is essentially solar, but one object (A447) is clearly Na deficient. These results are compatible with the expected abundance range estimated from the stochastic evolutionary halo model by Argast et al. (2000) when at the epoch of [Fe/H] $\\sim$ -2 the interstellar medium is supposed to become well-mixed.

  20. Meridional variation in tropospheric methane on Titan observed with AO spectroscopy at Keck and VLT

    CERN Document Server

    Ádámkovics, Máté; Hayes, Alexander G; Rojo, Patricio M; Corlies, Paul; Barnes, Jason W; Ivanov, Valentin D; Brown, Robert H; Baines, Kevin H; Buratti, Bonnie J; Clark, Roger N; Nicholson, Philip D; Sotin, Christophe

    2015-01-01

    The spatial distribution of the tropospheric methane on Titan was measured using near-infrared spectroscopy. Ground-based observations at 1.5$\\mu{\\rm m}$ (H-band) were performed during the same night using instruments with adaptive optics at both the W. M. Keck Observatory and at the Paranal Observatory on 17 July 2014 UT. The integral field observations with SINFONI on the VLT covered the entire H-band at moderate resolving power, $R=\\lambda/\\Delta\\lambda\\approx1,500$, while the Keck observations were performed with NIRSPAO near 1.55254$\\mu{\\rm m}$ at higher resolution, $R\\approx25,000$. The moderate resolution observations are used for flux calibration and for the determination of model parameters that can be degenerate in the interpretation of high resolution spectra. Line-by-line calculations of CH$_4$ and CH$_3$D correlated $k$ distributions from the HITRAN 2012 database were used, which incorporate revised line assignments near 1.5$\\mu{\\rm m}$. We fit the surface albedo and aerosol distributions in the ...

  1. The VLT-FLAMES Tarantula Survey XXI. Stellar spin rates of O-type spectroscopic binaries

    CERN Document Server

    Ramírez-Agudelo, O H; de Mink, S E; Hénault-Brunet, V; de Koter, A; Langer, N; Tramper, F; Gräfener, G; Evans, C J; Vink, J S; Dufton, P L; Taylor, W D

    2015-01-01

    The initial distribution of spin rates of massive stars is a fingerprint of their elusive formation process. It also sets a key initial condition for stellar evolution and is thus an important ingredient in stellar population synthesis. So far, most studies have focused on single stars. Most O stars are however found in multiple systems. By establishing the spin-rate distribution of a sizeable sample of O-type spectroscopic binaries and by comparing the distributions of binary sub-populations with one another as well as with that of presumed single stars in the same region, we aim to constrain the initial spin distribution of O stars in binaries, and to identify signatures of the physical mechanisms that affect the evolution of the massive stars spin rates. We use ground-based optical spectroscopy obtained in the framework of the VLT-FLAMES Tarantula Survey (VFTS) to establish the projected equatorial rotational velocities (\\vrot) for components of 114 spectroscopic binaries in 30 Doradus. The \\vrot\\ values a...

  2. Spectroscopic confirmation of high-redshift supernovae with the ESO VLT

    CERN Document Server

    Lidman, C E; Folatelli, G; Garavini, G; Nobili, S; Aldering, G; Amanullah, R; Antilogus, P; Astier, Pierre; Blanc, G; Burns, M S; Conley, A; Deustua, S E; Doi, M; Ellis, R; Fabbro, S; Fadeev, V; Gibbons, R; Goldhaber, G; Goobar, A; Groom, D E; Hook, I; Kashikawa, N; Kim, A G; Knop, R A; Lee Byung Cheol; Méndez, J; Morokuma, T; Motohara, K; Nugent, P; Pain, R; Perlmutter, S; Prasad, V; Quimby, R; Raux, J; Regnault, N; Ruiz-Lapuente, P; Sainton, G; Schaefer, B E; Schahmaneche, K; Smith, E; Spadafora, A L; Stanishev, V; Walton, N A; Wang, L; Wood-Vasey, W M; Yasuda, N

    2004-01-01

    We present VLT FORS1 and FORS2 spectra of 39 candidate high-redshift supernovae that were discovered as part of a cosmological study using Type Ia supernovae (SNe Ia) over a wide range of redshifts. From the spectra alone, 20 candidates are spectrally classified as SNe Ia with redshifts ranging from z=0.212 to z=1.181. Of the remaining 19 candidates, 1 might be a Type II supernova and 11 exhibit broad supernova-like spectral features and/or have supernova-like light curves. The candidates were discovered in 8 separate ground-based searches. In those searches in which SNe Ia at z ~ 0.5 were targeted, over 80% of the observed candidates were spectrally classified as SNe Ia. In those searches in which SNe Ia with z > 1 were targeted, 4 candidates with z > 1 were spectrally classified as SNe Ia and later followed with ground and space based observatories. We present the spectra of all candidates, including those that could not be spectrally classified as supernova.

  3. VLT/VIMOS integral field spectroscopy of luminous and ultraluminous infrared galaxies: 2D kinematic properties

    CERN Document Server

    Bellocchi, Enrica; Colina, Luis; Miralles-Caballero, Daniel

    2013-01-01

    We present and discuss the 2D kinematic properties of the ionized gas (Halpha) in a sample of 38 local (ultra) luminous infrared galaxies [(U)LIRGs] (31 LIRGs and 7 ULIRGs) observed with VIMOS at the VLT using integral field spectroscopy. This sample covers well the less studied LIRG luminosity range and includes isolated disks, interacting systems, and mergers. The majority of the galaxies have two main kinematically distinct components. One component (i.e., narrow or systemic) extends over the whole line-emitting region and is characterized by small to intermediate velocity dispersions (i.e., sigma from 30 to 160 km s^-1). It traces the overall velocity field. The second component (broad) has in general a larger velocity dispersion (up to 320 km s^-1), mainly found in the inner regions and generally blueshifted with respect to the systemic component. Most of the objects (76%) are dominated by rotation, more relevant in LIRGs than in ULIRGs. Isolated disks, interacting galaxies, and merging systems define a ...

  4. Testing intermediate-age stellar evolution models with VLT photometry of LMC clusters. I. The data

    CERN Document Server

    Gallart, C; Bertelli, G; Chiosi, C; Demarque, P; Girardi, L; Nasi, E; Woo, J H; Yi, S

    2003-01-01

    This is the first of a series of three papers devoted to the calibration of a few parameters of crucial importance in the modeling of the evolution of intermediate-mass stars, with special attention to the amount of convective core overshoot. To this end we acquired deep V and R photometry for three globular clusters of the Large Magellanic Cloud (LMC), namely NGC 2173, SL 556 and NGC 2155, in the age interval 1-3 Gyr. In this first paper, we describe the aim of the project, the VLT observations and data reduction, and we make preliminary comparisons of the color-magnitude diagrams with both Padova and Yonsei-Yale isochrones. Two following papers in this series present the results of a detailed analysis of these data, independently carried out by members of the Yale and Padova stellar evolution groups. This allows us to compare both sets of models and discuss their main differences, as well as the systematic effects that they would have to the determination of the ages and metallicities of intermediate-age si...

  5. A nearby GRB host galaxy: VLT/X-shooter observations of HG 031203

    CERN Document Server

    Guseva, N G; Fricke, K J; Henkel, C; 10.1051/0004-6361/201116765

    2011-01-01

    (abridged) Long-duration gamma-ray bursts (LGRBs) occur in galaxies of generally low metallicity. We aim at a spectroscopic analysis of HG 031203, the host galaxy of a LRGB burst, to obtain its properties. Based on VLT/X-shooter spectroscopic observations in the wavelength range 3200-24000A, we use standard direct methods to evaluate physical conditions and element abundances. The resolving power of the instrument also allowed us to trace the kinematics of the ionised gas. We derive an interstellar oxygen abundance of 12+logO/H=8.20+/-0.03. The observed fluxes of hydrogen lines correspond to the theoretical recombination values after correction for extinction with a single value C(Hbeta)=1.67. We produce the CLOUDY photoionisation HII region model that reproduces observed emission-line fluxes of different ions in the optical range. This model also predicts emission-line fluxes in the near-infrared (NIR) and mid-infrared (MIR) ranges that agree well with the observed ones. This implies that the star-forming re...

  6. Mid-infrared imaging of 25 local AGN with VLT-VISIR

    CERN Document Server

    Horst, Hannes; Gandhi, Poshak; Smette, Alain

    2009-01-01

    Aims. High angular resolution N-band imaging is used to discern the torus of active galactic nuclei (AGN) from its environment in order to allow a comparison of its mid-infrared properties to the expectations of the unified scenario for AGN. Methods. We present VLT-VISIR images of 25 low-redshift AGN of different Seyfert types, as well as N-band SEDs of 20 of them. In addition, we compare our results for 19 of them to Spitzer IRS spectra. Results. We find that at a resolution of ~ 0.35", all the nuclei of our observed sources are point-like, except for 2 objects whose extension is likely of instrumental origin. For 3 objects, however, we observed additional extended circumnuclear emission, even though our observational strategy was not designed to detect it. Comparison of the VISIR photometry and Spitzer spectrophotometry indicates that the latter is affected by extended emission in at least 7 out of 19 objects and the level of contamination is (0.20 ~ 0.85) * F_IRS. In particular, the 10 um silicate emission...

  7. The VLT-FLAMES Tarantula Survey XIV. The O-Type Stellar Content of 30 Doradus

    CERN Document Server

    Walborn, N R; Simon-Diaz, S; Apellaniz, J Maiz; Taylor, W D; Evans, C J; Markova, N; Lennon, D J; de Koter, A

    2014-01-01

    Detailed spectral classifications are presented for 352 O-B0 stars in the VLT-FLAMES Tarantula Survey, of which 213 O-type are of sufficient quality for further morphological analysis. Among them, six subcategories of special interest are distinguished. (1) Several new examples of the earliest spectral types O2-O3 have been found. (2) A group of extremely rapidly rotating main-sequence objects has been isolated, including the largest $v\\sin i$ values known, the spatial and radial-velocity distributions of which suggest ejection from the two principal ionizing clusters. (3) Several new examples of the evolved, rapidly rotating Onfp class show similar evidence. (4) No fewer than 48 members of the Vz category, hypothesized to be on or near the ZAMS, are found in this sample; in contrast to the rapid rotators, they are strongly concentrated to the ionizing clusters, supporting their interpretation as very young objects, as do their relatively faint absolute magnitudes. (5) A surprisingly large fraction of the mai...

  8. The VLT-FLAMES Tarantula Survey XII. Rotational velocities of the single O-type stars

    CERN Document Server

    Ramírez-Agudelo, O H; Sana, H; de Koter, A; Sabín-Sanjulían, C; de Mink, S E; Dufton, P L; Gräfener, G; Evans, C J; Herrero, A; Langer, N; Lennon, D J; Apellániz, J Maíz; Markova, N; Najarro, F; Puls, J; Taylor, W D; Vink, J S

    2013-01-01

    Aims. Using ground based multi-object optical spectroscopy obtained in the framework of the VLT-FLAMES Tarantula Survey (VFTS), we aim to establish the (projected) rotational velocity distribution for a sample of 216 presumably single O-type stars in 30 Doradus (30 Dor). Methods. We measured projected rotational velocities, \\vrot, by means of a Fourier transform method and a profile fitting method applied on a set of isolated spectral lines. We also used an iterative deconvolution procedure to infer the probability density, $\\rm{P(\\veq)}$, of the equatorial rotational velocity, \\veq. Results. The distribution of \\vrot\\ shows a two-component structure: a peak around 80 \\kms\\ and a high-velocity tail extending up to $\\sim$600 \\kms. This structure is also present in the inferred distribution $\\rm{P(\\veq)}$ with around 80% of the sample having 0 $<$ \\veq\\, $\\leq\\, 300$ \\kms\\ and the other 20% distributed in the high-velocity region. Conclusions. Most of the stars in our sample rotate with a rate less than 20%\\...

  9. The VLT-FLAMES Tarantula Survey I: Introduction and observational overview

    CERN Document Server

    Evans, C J; Henault-Brunet, V; Sana, H; de Koter, A; Simon-Diaz, S; Carraro, G; Bagnoli, T; Bastian, N; Bestenlehner, J M; Bonanos, A Z; Bressert, E; Brott, I; Campbell, M A; Cantiello, M; Clark, J S; Costa, E; Crowther, P A; de Mink, S E; Doran, E; Dufton, P L; Dunstall, P R; Friedrich, K; Garcia, M; Gieles, M; Graefener, G; Herrero, A; Howarth, I D; Izzard, R G; Langer, N; Lennon, D J; Apellaniz, J Maiz; Markova, N; Najarro, F; Puls, J; Ramirez, O H; Sabin, C; Smartt, S J; Stroud, V E; van Loon, J Th; Vink, J S; Walborn, N R

    2011-01-01

    The VLT-FLAMES Tarantula Survey (VFTS) is an ESO Large Programme that has obtained multi-epoch optical spectroscopy of over 800 massive stars in the 30 Doradus region of the Large Magellanic Cloud (LMC). Here we introduce our scientific motivations and give an overview of the survey targets, including optical and near-infrared photometry and comprehensive details of the data reduction. One of the principal objectives was to detect massive binary systems via variations in their radial velocities, thus shaping the multi-epoch observing strategy. Spectral classifications are given for the massive emission-line stars observed by the survey, including the discovery of a new Wolf-Rayet star (VFTS 682, classified as WN5h), 2' to the northeast of R136. To illustrate the diversity of objects encompassed by the survey, we investigate the spectral properties of sixteen targets identified by Gruendl & Chu from Spitzer photometry as candidate young stellar objects or stars with notable mid-infrared excesses. Detailed ...

  10. The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars

    CERN Document Server

    Dunstall, P R; Sana, H; Evans, C J; Howarth, I D; Simón-Díaz, S; de Mink, S E; Langer, N; Apellániz, J Maíz; Taylor, W D

    2015-01-01

    We investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to estimate relative radial velocities from the helium and metal absorption lines for each of our targets. Objects with significant radial-velocity variations (and with an amplitude larger than 16 km/s) are classified as spectroscopic binaries. We find an observed spectroscopic binary fraction (defined by periods of 0.1) for the B-type stars, f_B(obs) = 0.25 +/- 0.02, which appears constant across the field of view, except for the two older clusters (Hodge 301 and SL 639). These two clusters have significantly lower fractions of 0.08 +/- 0.08 and 0.10 +/- 0.09, respectively. Using synthetic populations and a model of our observed epochs and their potential biases, we constrain the intrinsic multiplicity properties of the dwarf and giant (i.e. relatively unevolved) B-type stars ...

  11. A Deep Optical Luminosity Function of NGC 6712 with the VLT Evidence for Severe Tidal Disruption

    CERN Document Server

    De Marchi, G; Paresce, F; Pulonen, L E; Marchi, Guido De; Leibundgut, Bruno; Paresce, Francesco; Pulone, Luigi

    1999-01-01

    The VLT on Cerro Paranal was used to observe four fields located at 2.3' from the center of the Galactic globular cluster NGC 6712 in the V and R bands. The resulting color-magnitude diagram shows a well defined main sequence reaching down to the 5 sigma detection limit at V~25, R~23.5 or approximately 4 mag below the main sequence turn-off, the deepest obtained so far on this cluster. This yields a main sequence luminosity function that peaks at M_R~4.5 and drops down to the 50% completeness limit at M_R~8.5. Transformation to a mass function via the latest mass-luminosity relation appropriate to this object indicates that the peak of the luminosity function corresponds to ~0.75 Msolar, a value significantly higher than the ~0.25 Msolar measured for most other clusters observed so far. Since this object, in its Galactic orbit, penetrates very deeply into the Galactic bulge with perigalactic distance of ~0.3 kpc, this result is the first strong evidence that tidal forces have stripped this cluster of a substa...

  12. VLT/X-shooter survey of near-infrared diffuse interstellar bands

    CERN Document Server

    Cox, N L J; Kaper, L; Ehrenfreund, P; Foing, B H; Ochsendorf, B B; van Hooff, S H M; Salama, F

    2014-01-01

    This paper presents a spectral survey of diffuse interstellar bands (DIBs) in the NIR range, from 0.9 to 2.5 micron. The observations were designed to detect new DIBs, confirm previously proposed NIR DIBs, and characterise their behaviour with respect to known line-of-sight properties (including the optical DIBs present in our spectra). X-shooter at the VLT was used to obtained medium-resolution spectra of eight known DIB targets and one telluric reference star. In addition to the known 9577, 9632, 11797, and 13175 Angstroms NIR DIBs, we confirm 9 out of the 13 NIR DIBs that were presented by Geballe and co-workers in 2011. Furthermore, we report 12 new NIR DIB candidates. The strengths of the strongest NIR DIBs show a general correlation with reddening, E(B-V), but with a large scatter. Several NIR DIBs are more strongly correlated with the 5780 Angstroms DIB strength than with E(B-V); this is especially the case for the 15268 Angstroms DIB. The NIR DIBs are strong: the summed equivalent widths of the five s...

  13. VLT/ISAAC H-band spectroscopy of embedded massive YSOs

    CERN Document Server

    Kendall, T R; Yun, J L

    2003-01-01

    We have performed intermediate resolution (R = 5000), high signal-to-noise H-band spectroscopy of a small, initial sample of three massive embedded young stellar objects (YSOs), using VLT/ISAAC. The sample has been selected from sources characterised in previous literature as being likely of OB spectral type, to be unambiguously associated with bright (H < 14) single point sources in the 2MASS database, and to have no optical counterparts. Of the targets observed, one object shows a ~B3 spectrum, similar to a main sequence object of the same spectral type. A second object exhibits weak HeI and H emission, indicating an early-type source: we detect HeII absorption, which supports a previous indirect derivation of the spectral type as mid-O. The third object does not show absorption lines, so no spectral type can de derived. It does, however, exhibit a rich spectrum of strong, broad emission lines and is likely to be surrounded by dense circumstellar material and at a very early evolutionary stage. Our resul...

  14. A VLT/FORS2 spectroscopic survey of individual stars in a transforming dwarf galaxy

    CERN Document Server

    Battaglia, G; Rejkuba, M

    2016-01-01

    Understanding the properties of dwarf galaxies is important not only to put them in their proper cosmological context, but also to understand the formation and evolution of the most common type of galaxies. Dwarf galaxies are divided into two main classes, dwarf irregulars (dIrrs) and dwarf spheroidals (dSphs), which differ from each other mainly because the former are gas-rich objects currently forming stars, while the latter are gas-deficient with no on-going star formation. Transition types (dT) are thought to represent dIs in the process of losing their gas, and can therefore shed light into the possible process of dwarf irregulars (dIrrs) becoming gas-deficient, passively evolving galaxies. Here we present preliminary results from our wide-area VLT/FORS2 MXU spectroscopic survey of the Phoenix dT, from which we obtained line-of-sight velocities and metallicities from the nIR Ca II triplet lines for a large sample of individual Red Giant Branch stars.

  15. An extensive VLT/X-shooter library of photospheric templates of pre-main sequence stars

    Science.gov (United States)

    Manara, C. F.; Frasca, A.; Alcalá, J. M.; Natta, A.; Stelzer, B.; Testi, L.

    2017-09-01

    Context. Studies of the formation and evolution of young stars and their disks rely on knowledge of the stellar parameters of the young stars. The derivation of these parameters is commonly based on comparison with photospheric template spectra. Furthermore, chromospheric emission in young active stars impacts the measurement of mass accretion rates, a key quantity for studying disk evolution. Aims: Here we derive stellar properties of low-mass (M⋆≲ 2 M⊙) pre-main sequence stars without disks, which represent ideal photospheric templates for studies of young stars. We also use these spectra to constrain the impact of chromospheric emission on the measurements of mass accretion rates. The spectra are reduced, flux-calibrated, and corrected for telluric absorption, and are made available to the community. Methods: We derive the spectral type for our targets by analyzing the photospheric molecular features present in their VLT/X-shooter spectra by means of spectral indices and comparison of the relative strength of photospheric absorption features. We also measure effective temperature, gravity, projected rotational velocity, and radial velocity from our spectra by fitting them with synthetic spectra with the ROTFIT tool. The targets have negligible extinction (AVhttp://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/605/A86

  16. VLT\\/UVES Abundances in Four Nearby Dwarf Spheroidal Galaxies II. Implications for Understanding Galaxy Evolution

    CERN Document Server

    Tolstoy, E; Shetrone, M; Primas, F; Hill, V; Szeifert, A K T; Tolstoy, Eline

    2003-01-01

    We have used UVES on VLT-UT2 to take spectra of 15 individual red giant stars in the centers of four nearby dwarf spheroidal galaxies: Sculptor, Fornax, Carina and Leo I. We measure the abundance variations of numerous elements in these low mass stars with a range of ages (1-15Gyr old). This means that we can effectively measure the chemical evolution of these galaxies WITH TIME. Our results show a significant spread in metallicity with age, but an overall trend consistent with what might be expected from a closed (or perhaps leaky) box chemical evolution scenario over the last 10-15Gyr. We notice that each of these galaxies show broadly similar abundance patterns for all elements measured. This suggests a fairly uniform progression of chemical evolution with time, despite quite a large range of star formation histories. It seems likely that these galaxies had similar initial conditions, and evolve in a similar manner with star formation occurring at a uniformly low rate, even if at different times. With our ...

  17. A VLT/NACO Study of Star Formation in the Massive Embedded Cluster RCW 38

    CERN Document Server

    DeRose, K L; Gutermuth, R A; Wolk, S J; Megeath, S T; Alves, J; Nürnberger, D

    2009-01-01

    We present adaptive optics (AO) near-infrared (JHKs) observations of the deeply embedded massive cluster RCW 38 using NACO on the VLT. Narrowband AO observations centered at wavelengths of 1.28, 2.12, and 2.17 micron were also obtained. The area covered by these observations is about 0.5 pc square, centered on the O star RCW 38 IRS2. We use the JHKs colors to identify young stars with infrared excess. Through a detailed comparison to a nearby control field, we find that most of the 337 stars detected in all three infrared bands are cluster members (~317), with essentially no contamination due to background or foreground sources. Five sources have colors suggestive of deeply embedded protostars, while 53 sources are detected at Ks only; their spatial distribution with respect to the extinction suggests they are highly reddened cluster members. Detectable Ks-band excess is found toward 29 +/- 3 % of the stars. For comparison to a similar area of Orion observed in the near-infrared, mass and extinction cuts are ...

  18. VLT/UVES Observations of Interstellar Molecules and Diffuse Bands in the Magellanic Clouds

    CERN Document Server

    Welty, D E; Gredel, R; Lambert, D L; Thorburn, J A

    2006-01-01

    We discuss the abundances of interstellar CH, CH+, and CN in the Magellanic Clouds (MC), derived from spectra of 7 SMC and 13 LMC stars obtained (mostly) with the VLT/UVES. CH and/or CH+ are detected toward 3 SMC and 9 LMC stars; CN is detected toward 2 stars. In the MC, the CH/H2 ratio is comparable to that found for diffuse Galactic molecular clouds in some sight lines, but is lower by factors up to 10-15 in others. The abundance of CH in the MC thus appears to depend on local physical conditions -- and not just on metallicity. The observed relationships between the column density of CH and those of CN, CH+, Na I, and K I in the MC are generally consistent with the trends observed in our Galaxy. Using existing data for the rotational populations of H2, we estimate temperatures, radiation field strengths, and local hydrogen densities for the diffuse molecular gas. Densities estimated from N(CH), assuming that CH is produced via steady-state gas-phase reactions, are considerably higher; much better agreement ...

  19. The next generation Cherenkov Telescope Array observatory: CTA

    Energy Technology Data Exchange (ETDEWEB)

    Vercellone, S., E-mail: stefano@ifc.inaf.it

    2014-12-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to the very high-energy gamma-ray astrophysics in the energy range 30 GeV–100 TeV, which will improve by about one order of magnitude the sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). In order to achieve such improved performance, for both the northern and southern CTA sites, four units of 23 m diameter Large Size Telescopes (LSTs) will be deployed close to the centre of the array with telescopes separated by about 100 m. A larger number (about 25 units) of 12 m Medium Size Telescopes (MSTs, separated by about 150 m), will cover a larger area. The southern site will also include up to 24 Schwarzschild–Couder dual-mirror medium-size Telescopes (SCTs) with the primary mirror diameter of 9.5 m. Above a few TeV, the Cherenkov light intensity is such that showers can be detected even well outside the light pool by telescopes significantly smaller than the MSTs. To achieve the required sensitivity at high energies, a huge area on the ground needs to be covered by Small Size Telescopes (SSTs) with a field of view of about 10° and an angular resolution of about 0.2°, making the dual-mirror configuration very effective. The SST sub-array will be composed of 50–70 telescopes with a mirror area of about 5–10 m{sup 2} and about 300 m spacing, distributed across an area of about 10 km{sup 2}. In this presentation we will focus on the innovative solution for the optical design of the medium and small size telescopes based on a dual-mirror configuration. This layout will allow us to reduce the dimension and the weight of the camera at the focal plane of the telescope, to adopt Silicon-based photo-multipliers as light detectors thanks to the reduced plate-scale, and to have an optimal imaging resolution on a wide field of view.

  20. The next generation Cherenkov Telescope Array observatory: CTA

    Science.gov (United States)

    Vercellone, S.

    2014-12-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to the very high-energy gamma-ray astrophysics in the energy range 30 GeV-100 TeV, which will improve by about one order of magnitude the sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). In order to achieve such improved performance, for both the northern and southern CTA sites, four units of 23 m diameter Large Size Telescopes (LSTs) will be deployed close to the centre of the array with telescopes separated by about 100 m. A larger number (about 25 units) of 12 m Medium Size Telescopes (MSTs, separated by about 150 m), will cover a larger area. The southern site will also include up to 24 Schwarzschild-Couder dual-mirror medium-size Telescopes (SCTs) with the primary mirror diameter of 9.5 m. Above a few TeV, the Cherenkov light intensity is such that showers can be detected even well outside the light pool by telescopes significantly smaller than the MSTs. To achieve the required sensitivity at high energies, a huge area on the ground needs to be covered by Small Size Telescopes (SSTs) with a field of view of about 10° and an angular resolution of about 0.2°, making the dual-mirror configuration very effective. The SST sub-array will be composed of 50-70 telescopes with a mirror area of about 5-10 m2 and about 300 m spacing, distributed across an area of about 10 km2. In this presentation we will focus on the innovative solution for the optical design of the medium and small size telescopes based on a dual-mirror configuration. This layout will allow us to reduce the dimension and the weight of the camera at the focal plane of the telescope, to adopt Silicon-based photo-multipliers as light detectors thanks to the reduced plate-scale, and to have an optimal imaging resolution on a wide field of view.

  1. The Research Productivity of Small Telescopes and Space Telescopes

    CERN Document Server

    Ringwald, F A; Lovell, R L; Kays, S A; Torres, Y V A

    2003-01-01

    We present statistics on the research productivity of astronomical telescopes. These were compiled by finding papers in which new data were presented, noting which telescopes were used, and then counting the number of papers, number of pages, and other statistics. The journals used were the Astronomical Journal, the Astrophysical Journal (including the Letters and Supplements), and the Publications of the Astronomical Society of the Pacific. We also compiled citations from the Science Citation Index. This work was designed to be similar to that of Trimble (1995), except that more recent journals (from 1995) and citations (from 1998) were used. We also did not restrict our sample to large telescopes only: we included all telescopes from which new data were presented, the smallest of which was a 0.1-m. The data were gathered by first-year work-study undergraduates, who were instructed to include data for all telescopes for which they found new data were included in the journals. A by-product of this research wa...

  2. Hundred metre virtual telescope captures unique detailed colour image

    Science.gov (United States)

    2009-02-01

    appearance of the star before, but it is quite astounding that we can now see it, and in colour." Although it is only 15 by 15 pixel across, the reconstructed image shows an extreme close-up of a star 100 times larger than the Sun, a diameter corresponding roughly to the distance between the Earth and the Sun. This star is, in turn, surrounded by a sphere of molecular gas, which is about three times as large again. T Leporis, in the constellation of Lepus (the Hare), is located 500 light-years away. It belongs to the family of Mira stars, well known to amateur astronomers. These are giant variable stars that have almost extinguished their nuclear fuel and are losing mass. They are nearing the end of their lives as stars, and will soon die, becoming white dwarfs. The Sun will become a Mira star in a few billion years, engulfing the Earth in the dust and gas expelled in its final throes. Mira stars are among the biggest factories of molecules and dust in the Universe, and T Leporis is no exception. It pulsates with a period of 380 days and loses the equivalent of the Earth's mass every year. Since the molecules and dust are formed in the layers of atmosphere surrounding the central star, astronomers would like to be able to see these layers. But this is no easy task, given that the stars themselves are so far away -- despite their huge intrinsic size, their apparent radius on the sky can be just half a millionth that of the Sun. "T Leporis looks so small from the Earth that only an interferometric facility, such as the VLTI at Paranal, can take an image of it. VLTI can resolve stars 15 times smaller than those resolved by the Hubble Space Telescope," says Le Bouquin. To create this image with the VLTI astronomers had to observe the star for several consecutive nights, using all the four movable 1.8-metre VLT Auxiliary Telescopes (ATs). The ATs were combined in different groups of three, and were also moved to different positions, creating more new interferometric

  3. Schwarzschild-Couder Telescope for the Cherenkov Telescope Array

    CERN Document Server

    Meagher, Kevin J

    2014-01-01

    The Cherenkov Telescope Array (CTA) is the next major ground-based observatory for gamma-ray astronomy. With CTA gamma-ray sources will be studied in the very-high energy gamma-ray range of a few tens of GeV to 100 TeV with up to ten times better sensitivity than available with current generation instruments. We discuss the proposed US contribution to CTA that comprises imaging atmospheric Cherenkov telescope with Schwarzschild-Couder (SC) optics. Key features of the SC telescope are a wide field of view of eight degrees, a finely pixelated camera with silicon photomultipliers as photon detectors, and a compact and power efficient 1 GS/s readout. The progress in both the optical system and camera development are discussed in this paper.

  4. GSMT Education: Teaching about Adaptive Optics and Site Selection Using Extremely Large Telescopes

    Science.gov (United States)

    Sparks, R. T.; Pompea, S. M.

    2010-08-01

    Giant Segmented Mirror Telescopes (GSMT) represents the next generation of extremely large telescopes (ELT). Currently there are three active ELT projects, all established as international partnerships to build telescopes of greater than 20 meters aperture. Two of these have major participation by U.S. institutions: the Giant Magellan Telescope and the Thirty Meter Telescope. The ESO-ELT is under development by the European Southern Observatory and other European institutions. We have developed educational activities to accompany the design phase of these projects. The current activities focus on challenges faced in the design and site selection of a large telescope. The first module is on site selection. This online module is based on the successful Astronomy Village program model. Students evaluate several potential sites to decide where to build the GSMT. They must consider factors such as weather, light pollution, seeing, logistics, and geography. The second project has developed adaptive optics teaching units suitable for high school.

  5. VLT/UVES abundances in four nearby dwarf spheroidal galaxies. I. Nucleosynthesis and abundance ratios

    NARCIS (Netherlands)

    Shetrone, M; Venn, KA; Tolstoy, E; Primas, F; Hill, [No Value; Kaufer, A

    2003-01-01

    We have used the Ultraviolet Echelle Spectrograph (UVES) on Kueyen (UT2) of the Very Large Telescope to take spectra of 15 individual red giants in the Sculptor, Fornax, Carina, and Leo I dwarf spheroidal galaxies (dSph's). We measure the abundances of alpha-, iron peak, first s-process, second s-pr

  6. VLT/UVES abundances in four nearby dwarf spheroidal galaxies. II. Implications for understanding galaxy evolution

    NARCIS (Netherlands)

    Tolstoy, E; Venn, KA; Shetrone, M; Primas, F; Hill, [No Value; Kaufer, A; Szeifert, T

    2003-01-01

    We have used the Ultraviolet Visual-Echelle Spectrograph (UVES) on Kueyen (UT2) of the Very Large Telescope to take spectra of 15 individual red giant stars in the centers of four nearby dwarf spheroidal galaxies (dSph's) : Sculptor, Fornax, Carina, and Leo I. We measure the abundance variations of

  7. Feature-based telescope scheduler

    Science.gov (United States)

    Naghib, Elahesadat; Vanderbei, Robert J.; Stubbs, Christopher

    2016-07-01

    Feature-based Scheduler offers a sequencing strategy for ground-based telescopes. This scheduler is designed in the framework of Markovian Decision Process (MDP), and consists of a sub-linear online controller, and an offline supervisory control-optimizer. Online control law is computed at the moment of decision for the next visit, and the supervisory optimizer trains the controller by simulation data. Choice of the Differential Evolution (DE) optimizer, and introducing a reduced state space of the telescope system, offer an efficient and parallelizable optimization algorithm. In this study, we applied the proposed scheduler to the problem of Large Synoptic Survey Telescope (LSST). Preliminary results for a simplified model of LSST is promising in terms of both optimality, and computational cost.

  8. Scientific management of Space Telescope

    Science.gov (United States)

    Odell, C. R.

    1981-01-01

    A historical summay is given on the science management of the Space Telescope, the inception of which began in 1962, when scientists and engineers first recommended the development of a nearly diffraction limited substantial-size optical telescope. Phase A, the feasibility requirements generation phase, began in 1971 and consisted largely of NASA scientists and a NASA design. Phase B, the preliminary design phase, established a tiered structure of scientists, led by the Large Space Telescope operations and Management Work Group. A Mission Operations Working Group headed six instrument definition teams to develop the essential instrument definitions. Many changes took place during Phase B, before design and development, which began in 1978 and still continues today.

  9. FAMOUS. The fluorescence telescope prototype

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, Johannes; Bretz, Thomas; Hebbeker, Thomas; Lauscher, Markus; Middendorf, Lukas; Niggemann, Tim; Peters, Christine; Sommer, Dominik; Stephan, Maurice [III. Physikalisches Institut A, RWTH Aachen University (Germany); Auffenberg, Jan; Schaufel, Merlin [III. Physikalisches Institut B, RWTH Aachen University (Germany)

    2015-07-01

    One of the most successful techniques for the detection of air showers produced by ultra-high-energy cosmic rays are fluorescence telescopes. The light produced by de-exciting nitrogen in the atmosphere is typically detected by photomultiplier tubes (PMTs). This technique has been successfully used by the Pierre Auger Observatory in Argentina for many years. Silicon photomultipliers (SiPMs) promise higher photon detection efficiencies than PMTs. This and other advantages motivate the construction of the fluorescence telescope prototype FAMOUS (First Auger Multi-pixel photon counter camera for the Observation of Ultra-high-energy air Showers) which makes use of SiPMs. In this talk we discuss the FAMOUS telescope with a new 64-pixel camera including power supply and DAQ.

  10. LSST telescope and site status

    Science.gov (United States)

    Gressler, William J.

    2016-07-01

    The Large Synoptic Survey Telescope (LSST) Project1 received its construction authorization from the National Science Foundation in August 2014. The Telescope and Site (T and S) group has made considerable progress towards completion in subsystems required to support the scope of the LSST science mission. The LSST goal is to conduct a wide, fast, deep survey via a 3-mirror wide field of view optical design, a 3.2-Gpixel camera, and an automated data processing system. The summit facility is currently under construction on Cerro Pachón in Chile, with major vendor subsystem deliveries and integration planned over the next several years. This paper summarizes the status of the activities of the T and S group, tasked with design, analysis, and construction of the summit and base facilities and infrastructure necessary to control the survey, capture the light, and calibrate the data. All major telescope work package procurements have been awarded to vendors and are in varying stages of design and fabrication maturity and completion. The unique M1M3 primary/tertiary mirror polishing effort is completed and the mirror now resides in storage waiting future testing. Significant progress has been achieved on all the major telescope subsystems including the summit facility, telescope mount assembly, dome, hexapod and rotator systems, coating plant, base facility, and the calibration telescope. In parallel, in-house efforts including the software needed to control the observatory such as the scheduler and the active optics control, have also seen substantial advancement. The progress and status of these subsystems and future LSST plans during this construction phase are presented.

  11. High-redshift supernova rates measured with the gravitational telescope A1689

    CERN Document Server

    Petrushevska, Tanja; Goobar, Ariel; Fabbro, Sebastien; Johansson, Joel; Kjellsson, Tor; Lidman, Chris; Paech, Kerstin; Richard, Johan; Dahle, Hakon; Ferretti, Raphael; Kneib, Jean-Paul; Limousin, Marceau; Nordin, Jakob; Stanishev, Vallery

    2016-01-01

    We present a ground-based near-infrared search for lensed supernovae behind the massive cluster Abell 1689 at z=0.18, one of the most powerful gravitational telescopes that nature provides. Our survey was based on multi-epoch $J$-band observations with the HAWK-I instrument on VLT, with supporting optical data from the Nordic Optical Telescope. Our search resulted in the discovery of five high-redshift, $0.671

  12. LISA telescope spacer design investigations

    Science.gov (United States)

    Sanjuan, Josep; Mueller, Guido; Livas, Jeffrey; Preston, Alix; Arsenovic, Petar; Castellucci, Kevin; Generie, Joseph; Howard, Joseph; Stebbins, Robin

    The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave observa-tory with the goal of observing Gravitational Waves (GWs) from astronomical sources in a frequency range from 30 µHz to 0.1 Hz. The detection of GWs at such low frequency requires measurements of distances at the pico-meter level between bodies separated by 5 million kilo-meters. The LISA mission consists of three identical spacecraft (SC) separated by 5 × 106 km forming an equilateral triangle. Each SC contains two optical assemblies and two vacuum en-closures housing one proof mass (PM) in geodesic (free fall) motion each. The two assemblies on one SC are each pointing towards an identical assembly on each of the other two SC to form a non-equal arm interferometer. The measurement of the GW strain is done by measuring the change in the length of the optical path between the PMs of one arm relative to the other arms caused by the pass of a GW. An important element of the Interferometric Measurement System (IMS) is the telescope which, on one hand, gathers the light coming from the far SC (˜100 pW) and, on the other hand, expands and collimates the small outgoing beam ( 1 W) and sends it to the far SC. Due to the very demanding sensitivity requirements care must be taken in the design and validation of the telescope not to degrade the IMS performance. For instance, the diameter of the telescope sets the the shot noise of the IMS and depends critically on the diameter of the primary and the divergence angle of the outgoing beam. As the telescope is rather fast telescope, the divergence angle is a critical function of the overall separation between the primary and secondary. Any long term changes of the distance of more than a a few micro-meter would be detrimental to the LISA mission. Similarly challenging are the requirements on the in-band path-length noise for the telescope which has to be kept below 1 pm Hz-1/2 in the LISA band. Different configurations (on-axis/off axis

  13. The network of INTA telescopes

    Science.gov (United States)

    Cuesta, L.

    2008-06-01

    The Spanish Instituto Nacional de Técnica Aeroespacial has a network of three telescopes located at some of the best places for astronomy in mainland Spain. The first is at the Observatorio de Calar Alto in Almeria, at an altitude of more than 2100 m. The second is near Calatayud in Zaragoza, at the summit of a 1400-m high mountain. The last is on the campus of the Instituto Nacional de Técnica Aerospatial (INTA), in Madrid. The three telescopes are either 40 or 50 cm in diameter and will be available for communications and educational projects.

  14. Wide field of view telescope

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, Mark R. (Albuquerque, NM); McGraw, John T. (Placitas, NM); Zimmer, Peter C. (Albuquerque, NM)

    2008-01-15

    A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

  15. Superconductor lunar telescopes --Abstract only

    Science.gov (United States)

    Chen, P. C.; Pitts, R.; Shore, S.; Oliversen, R.; Stolarik, J.; Segal, K.; Hojaji, H.

    1994-01-01

    We propose a new type of telescope designed specifically for the lunar environment of high vacuum and low temperature. Large area UV-Visible-IR telescope arrays can be built with ultra-light-weight replica optics. High T(sub c) superconductors provide support, steering, and positioning. Advantages of this approach are light-weight payload compatible with existing launch vehicles, configurable large area optical arrays, no excavation or heavy construction, and frictionless electronically controlled mechanisms. We have built a prototype and will be demonstarting some of its working characteristics.

  16. Highlights from the Telescope Array

    Science.gov (United States)

    Matthews, J. N.

    2016-11-01

    The Telescope Array measures the properties of ultra high energy cosmic ray induced extensive air showers. We do this using a variety of techniques including an array of scintillator detectors to sample the footprint of the air shower when it reaches the Earth's surface and telescopes to measure the fluorescence and Cerenkov light of the air shower. From this we determine the energy spectrum and chemical composition of the primary particles. We also search for sources of cosmic rays and anisotropy. We have found evidence of a possible source of ultra high energy cosmic rays in the northern sky. The experiment and its most recent measurements will be discussed.

  17. Autonomous Dome for Robotic Telescope

    CERN Document Server

    Kumar, Akash; Ganesh, Shashikiran

    2016-01-01

    Physical Research Laboratory operates a 50cm robotic observatory at Mount Abu. This Automated Telescope for Variability Studies (ATVS) makes use of Remote Telescope System 2 (RTS2) for autonomous operations. The observatory uses a 3.5m dome from Sirius Observatories. We have developed electronics using Arduino electronic circuit boards with home grown logic and software to control the dome operations. We are in the process of completing the drivers to link our Arduino based dome controller with RTS2. This document is a short description of the various phases of the development and their integration to achieve the required objective.

  18. Mapping of Ozone on Mars at Infrared Wavelengths Using Crires at VLT

    Science.gov (United States)

    Radeva, Y. L.; Mumma, M. J.; Villanueva, G.; Novak, R.; Hartogh, P.; Encrenaz, T.; Kaufl, H.; Smette, A.

    2010-12-01

    We present spatially resolved maps of ozone and water on Mars, acquired on 21 August 2009 using the ultra-high resolution infrared spectrometer CRIRES at ESO’s VLT (Paranal, Chile). On Mars, the season was mid-summer in the South (Ls = 325) and the latitudinal resolution was 10 degrees FWHM at disk center. Ozone is produced by recombination of photochemically produced O and O2. It is destroyed by UV photolysis (with O2 (a1Dg) as a principal product) but also by reaction with odd hydrogen species (especially, H - a product of H2O vapor photolysis). Thus, simultaneous measurements of water and ozone can test this relationship. We quantified ozone using spectral lines (near 1.27 mm) of O2 (a1Dg). The emission from O2 (a1Dg) serves as a tracer for O3 above 20 km, since at lower altitudes collisions with CO2 quench the excited O2 (a1Dg) molecules. We confirmed the vertical location of the O2 (a1Dg) emission by extracting rotational temperatures from line-by-line ratios, and comparing them with standard vertical temperature profiles for this season and location(s). On the same night, we also obtained 2-D (lat-long) maps of Martian water from multiple H2O lines detected in the 3.3 mm region. We compare our retrieved distributions for ozone (latitude and altitude) with predictions of Lefevre et al. [I] based on their comprehensive 3-D circulation and photochemical model for the Martian atmosphere. Acknowledgements: This work was funded by NASA’s R&A Programs in Astrobiology (344-53-51), Planetary Astronomy (344-32-51-96), and Planetary Atmospheres (NNX09AB65G). We gratefully acknowledge the Director and staff of the European Southern Observatory, for supporting these observations. References: [I] Lefevre et al. (2004), J. of Geophys. Res. 109, E07004

  19. Spectral mapping of comet 67P/Churyumov-Gerasimenko with VLT/MUSE and SINFONI

    Science.gov (United States)

    Guilbert-Lepoutre, Aurelie; Besse, Sebastien; Snodgrass, Colin; Yang, Bin

    2016-10-01

    Comets are supposedly the most primitive objects in the solar system, preserving the earliest record of material from the nebula out of which our Sun and planets were formed, and thus holding crucial clues on the early phases of the solar system formation and evolution. For most small bodies in the solar system we can only access the surface properties, whereas active comet nuclei lose material from their subsurface, so that understanding cometary activity represents an unique opportunity to assess their internal composition, and by extension the composition, the temperature and pressure conditions of the protoplanetary disk at their place of formation.The ESA/Rosetta mission is performing the most thorough investigation of a comet ever made. Rosetta is measuring properties of comet 67P/Churyumov-Gerasimenko at distances between 5 and hundreds of km from the nucleus. However, it is unable to make any measurement over the thousands of km of the rest of the coma. Fortunately, the outer coma is accessible from the ground. In addition, we currently lack an understanding of how the very detailed information gathered from space-based observations can be extrapolated to the many ground-based observations that we can potentially perform. Combining parallel in situ observations with observations from the ground therefore gives us a great opportunity, not only to understand the behavior of 67P, but also to other comets observed exclusively from Earth. As part of the many observations taken from the ground, we have performed a spectral mapping of 67's coma using two IFU instruments mounted on the VLT: MUSE in the visible, and SINFONI in the near-infrared. The observations, carried out in March 2016, will be presented and discussed.

  20. Ground-based CCD astrometry with wide field imagers. II. A star catalogue for M67: WFI@2.2m MPG/ESO astrometry, FLAMES@VLT radial velocities

    CERN Document Server

    Yadav, R K S; Piotto, G; Anderson, J; Cassisi, S; Villanova, S; Platais, I; Pasquini, L; Momany, Y; Sagar, R

    2008-01-01

    The solar-age open cluster M67 (C0847+120, NGC2682) is a touchstone in studies of the old Galactic disk. Despite its outstanding role, the census of cluster membership for M67 at fainter magnitudes and their properties are not well-established. Using the proprietary and archival ESO data, we have obtained astrometric, photometric, and radial velocities of stars in a 34'x 33' field centered on the old open cluster M67. The two-epoch archival observations separated by 4 years and acquired with the Wide Field Imager at the 2.2m MPG/ESO telescope have been reduced with our new astrometric techniques, as described in the first paper of this series. The same observations served to derive calibrated BVI photometry in M67. Radial velocities were measured using the archival and new spectroscopic data obtained at VLT. We have determined relative proper motions and membership probabilities for ~2,400 stars. The precision of proper motions for optimally exposed stars is ~2 mas/yr, gradually degrading down to ~5 mas/yr at...

  1. Clumpy dust clouds and extended atmosphere of the AGB star W Hya revealed with VLT/SPHERE-ZIMPOL and VLTI/AMBER II. Time variations between pre-maximum and minimum light

    CERN Document Server

    Ohnaka, Keiichi; Hofmann, Karl-Heinz

    2016-01-01

    Our recent visible polarimetric images of the well-studied AGB star W Hya taken at pre-maximum light (phase 0.92) with VLT/SPHERE-ZIMPOL have revealed clumpy dust clouds close to the star at ~2 Rstar. We present second-epoch SPHERE-ZIMPOL observations of W Hya at minimum light (phase 0.54) in the continuum (645, 748, and 820 nm), in the Halpha line (656.3 nm), and in the TiO band (717 nm) as well as high-spectral resolution long-baseline interferometric observations in 2.3 micron CO lines with the AMBER instrument at the Very Large Telescope Interferometer (VLTI). The high-spatial resolution polarimetric images have allowed us to detect clear time variations in the clumpy dust clouds as close as 34--50~mas (1.4--2.0 Rstar) to the star. We detected the formation of a new dust cloud and the disappearance of one of the dust clouds detected at the first epoch. The Halpha and TiO emission extends to ~150 mas (~6 Rstar), and the Halpha images reveal time variations. The degree of linear polarization is higher at mi...

  2. The dust environment of comet 67P/Churyumov-Gerasimenko from Rosetta OSIRIS and VLT observations in the 4.5 to 2.9 au heliocentric distance range inbound

    CERN Document Server

    Moreno, F; Hainaut, O; Tubiana, C; Sierks, H; Barbieri, C; Lamy, P L; Rodrigo, R; Koschny, D; Rickman, H; Keller, H U; Agarwal, J; AHearn, M F; Barucci, M A; Bertaux, J L; Bertini, I; Besse, S; Bodewits, D; Cremonese, G; Da Deppo, V; Davidsson, B; Debei, S; De Cecco, M; Ferri, F; Fornasier, S; Fulle, M; Groussin, O; Gutierrez, P J; Marques, P Gutierrez; Guettler, C; Hviid, S F; Ip, W H; Jorda, L; Knollenberg, J; Kovacs, G; Kramm, J R; Kuehrt, E; Kueppers, M; Lara, L M; Lazzarin, M; Moreno, J J Lopez; Marzari, F; Mottola, S; Naletto, G; Oklay, N; Pajola, M; Thomas, N; Vincent, J B; Della Corte, V; Fitzsimmons, A; Faggi, S; Jehin, E; Opitom, C; Tozzi, G P

    2016-01-01

    The ESA Rosetta spacecraft, currently orbiting around comet 67P, has already provided in situ measurements of the dust grain properties from several instruments, particularly OSIRIS and GIADA. We propose adding value to those measurements by combining them with ground-based observations of the dust tail to monitor the overall, time-dependent dust-production rate and size distribution. To constrain the dust grain properties, we take Rosetta OSIRIS and GIADA results into account, and combine OSIRIS data during the approach phase (from late April to early June 2014) with a large data set of ground-based images that were acquired with the ESO Very Large Telescope (VLT) from February to November 2014. A Monte Carlo dust tail code has been applied to retrieve the dust parameters. Key properties of the grains (density, velocity, and size distribution) were obtained from Rosetta observations: these parameters were used as input of the code to considerably reduce the number of free parameters. In this way, the overall...

  3. The Advanced Telescope for High Energy Astrophysics

    Science.gov (United States)

    Guainazzi, Matteo

    2017-08-01

    Athena (the Advanced Telescope for High Energy Astrophysics) is a next generation X-ray observatory currently under study by ESA for launch in 2028. Athena is designed to address the Hot and Energetic Universe science theme, which addresses two key questions: 1) How did ordinary matter evolve into the large scale structures we see today? 2) How do black holes grow and shape the Universe. To address these topics Athena employs an innovative X-ray telescope based on Silicon Pore Optics technology to deliver extremely light weight and high throughput, while retaining excellent angular resolution. The mirror can be adjusted to focus onto one of two focal place instruments: the X-ray Integral Field Unit (X-IFU) which provides spatially-resolved, high resolution spectroscopy, and the Wide Field Imager (WFI) which provides spectral imaging over a large field of view, as well as high time resolution and count rate tolerance. Athena is currently in Phase A and the study status will be reviewed, along with the scientific motivations behind the mission.

  4. The Zadko Telescope: Exploring the Transient Universe

    Science.gov (United States)

    Coward, D. M.; Gendre, B.; Tanga, P.; Turpin, D.; Zadko, J.; Dodson, R.; Devogéle, M.; Howell, E. J.; Kennewell, J. A.; Boër, M.; Klotz, A.; Dornic, D.; Moore, J. A.; Heary, A.

    2017-01-01

    The Zadko telescope is a 1 m f/4 Cassegrain telescope, situated in the state of Western Australia about 80-km north of Perth. The facility plays a niche role in Australian astronomy, as it is the only meter class facility in Australia dedicated to automated follow-up imaging of alerts or triggers received from different external instruments/detectors spanning the entire electromagnetic spectrum. Furthermore, the location of the facility at a longitude not covered by other meter class facilities provides an important resource for time critical projects. This paper reviews the status of the Zadko facility and science projects since it began robotic operations in March 2010. We report on major upgrades to the infrastructure and equipment (2012-2014) that has resulted in significantly improved robotic operations. Second, we review the core science projects, which include automated rapid follow-up of gamma ray burst (GRB) optical afterglows, imaging of neutrino counterpart candidates from the ANTARES neutrino observatory, photometry of rare (Barbarian) asteroids, supernovae searches in nearby galaxies. Finally, we discuss participation in newly commencing international projects, including the optical follow-up of gravitational wave (GW) candidates from the United States and European GW observatory network and present first tests for very low latency follow-up of fast radio bursts. In the context of these projects, we outline plans for a future upgrade that will optimise the facility for alert triggered imaging from the radio, optical, high-energy, neutrino, and GW bands.

  5. New telescope designs suitable for massively-multiplexed spectroscopy

    CERN Document Server

    Pasquini, L; Ellis, R; de Zeeuw, T

    2016-01-01

    We present two novel designs for a telescope suitable for massively-multiplexed spectroscopy. The first is a very wide field Cassegrain telescope optimised for fibre feeding. It provides a Field Of View (FOV) of 2.5 degrees diameter with a 10m primary mirror. It is telecentric and works at F/3, optimal for fibre injection. As an option, a gravity invariant focus for the central 10 arc-minutes can be added, to host, for instance, a giant integral field unit (IFU). It has acceptable performance in the 360-1300 nm wavelength range. The second concept is an innovative five mirror telescope design based on a Three Mirror Anastigmatic (TMA) concept. The design provides a large FOV in a convenient, gravity- invariant focal plane, and is scalable to a range of telescope diameters. As specific example, we present a 10m telescope with a 1.5 degree diameter FOV and a relay system that allows simultaneous spectroscopy with 10,000 mini-IFUs over a square degree, or, alternatively a 17.5 square arcminutes giant IFU, by usi...

  6. Sparse aperture masking at the VLT. II. Detection limits for the eight debris disks stars β Pic, AU Mic, 49 Cet, η Tel, Fomalhaut, g Lup, HD 181327 and HR 8799

    Science.gov (United States)

    Gauchet, L.; Lacour, S.; Lagrange, A.-M.; Ehrenreich, D.; Bonnefoy, M.; Girard, J. H.; Boccaletti, A.

    2016-10-01

    Context. The formation of planetary systems is a common, yet complex mechanism. Numerous stars have been identified to possess a debris disk, a proto-planetary disk or a planetary system. The understanding of such formation process requires the study of debris disks. These targets are substantial and particularly suitable for optical and infrared observations. Sparse aperture masking (SAM) is a high angular resolution technique strongly contributing to probing the region from 30 to 200 mas around the stars. This area is usually unreachable with classical imaging, and the technique also remains highly competitive compared to vortex coronagraphy. Aims: We aim to study debris disks with aperture masking to probe the close environment of the stars. Our goal is either to find low-mass companions, or to set detection limits. Methods: We observed eight stars presenting debris disks (β Pictoris, AU Microscopii, 49 Ceti, η Telescopii, Fomalhaut, g Lupi, HD 181327, and HR 8799) with SAM technique on the NaCo instrument at the Very Large Telescope (VLT). Results: No close companions were detected using closure phase information under 0.5'' of separation from the parent stars. We obtained magnitude detection limits that we converted to Jupiter masses detection limits using theoretical isochrones from evolutionary models. Conclusions: We derived upper mass limits on the presence of companions in the area of a few times the telescope's diffraction limits around each target star. Based on observations collected at the European Southern Observatory (ESO) during runs 087.C-0450(A), 087.C-0450(B) 087.C-0750(A), 088.C-0358(A).All magnitude detection limits maps are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/595/A31

  7. Results from the AMANDA telescope

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, J.; Bai, X.; Barwick, S.W.; Becka, T.; Becker, K.-H.; Bernardini, E.; Bertrand, D.; Binon, F.; Biron, A.; Boeser, S.; Botner, O.; Bouhali, O.; Burgess, T.; Carius, S.; Castermans, T.; Chirkin, D.; Conrad, J.; Cooley, J.; Cowen, D.F.; Davour, A.; De Clercq, C.; DeYoung, T.; Desiati, P.; Dewulf, J.-P.; Ekstroem, P.; Feser, T.; Gaisser, T.K.; Ganupati, R.; Gaug, M.; Geenen, H.; Gerhardt, L.; Goldschmidt, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Hardtke, R.; Hauschildt, T.; Hellwig, M.; Herquet, Ph.; Hill, G.C.; Hulth, P.O.; Hultqvist, K.; Hundertmark, S.; Jacobsen, J.; Karle, A.; Koepke, L.; Kuehn, K.; Kowalski, M.; Lamoureux, J.I.; Leich, H.; Leuthold, M.; Lindahl, P.; Liubarsky, I.; Madsen, J.; Mandli, K.; Marciniewski, P.; Matis, H.S.; McParland, C.P.; Messarius, T.; Minaeva, Y.; Miocinovic, P.; Morse, R.; Nahnhauer, R.; Neunhoeffer, T.; Niessen, P.; Nygren, D.R.; Ogelman, H.; Olbrechts, Ph.; Perez de los Heros, C.; Pohl, A.C.; Price, P.B.; Przybylski, G.T.; Rawlins, K.; Resconi, E.; Rhode, W.; Ribordy, M.; Richter, S.; Rodriguez Martino, J.; Sander, H.-G.; Schmidt, T.; Schneider, D.; Schinarakis, K.; Schwarz, R.; Silvestri, A.; Solarz, M.; Spiczak, G.M.; Spiering, C.; Steele, D.; Steffen, P.; Stokstad, R.G.; Sudoff, P.; Sudoff, K.-H.; Sulanke, K.-H.; Taboada, I.; Thollander, L.; Tilav, S.; Wagner, W.; Walck, C.; Weinheimer, C.; Wiebusch, C.H.; Wiedemann, C.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Yodh, G.; Young, S

    2003-06-30

    We present results from the AMANDA high energy neutrino telescope located at the South Pole. They include measurements of the atmospheric neutrino flux, search for UHE point sources, and diffuse sources producing electromagnetic/hadronic showers at the detector or close to it.

  8. The Atacama Submillimeter Telescope Experiment

    Science.gov (United States)

    Sekimoto, Yutaro; Kawabe, Ryohei; Yamamoto, Satoshi; Hasegawa, Tetsuo

    1999-10-01

    We have a plan to operate a new 10 m telescope at Pampa la Bola (4800 m) in Chile as one of Japanese R&D activities for Atacama Large Millimeter/Submillimeter Array. Technical and scientific purposes in this experiment are to develop and evaluate a high precision 10 m antenna under exposed conditions at the site, to develop and test low-noise submillimeter receivers and new SIS photon detectors, to test various techniques for submillimeter observations, and to explore the southern hemisphere in the submillimeter band: Galactic Center, Magellanic Clouds, and so on. The SIS mixer receivers at the Cassegrain focus covers 100, 230, 350, 500, 670, and 810 GHz bands for spectral line observations. A digital autocorrelator consisted of four modules with 500 MHz bandwidth is mounted in a container near the telescope. Two power generators with a capability of 200 kW are installed at the site. The telescope will be operated remotely from Japan via a commercial satellite communication system. After a test operation at Nobeyama for one and a half years, the telescope will be transported to Pampa la Bola in August 2001.

  9. Cern Axion Solar Telescope (CAST)

    CERN Multimedia

    2002-01-01

    The CERN Solar Axion Telescope, CAST, aims to shed light on a 30-year-old riddle of particle physics by detecting axions originating from the 15 million degree plasma in the Sun 's core. Axions were proposed as an extension to the Standard Model of particle physics to explain why CP violation is observed in weak but not strong interactions.

  10. Monster telescope hunts blue planets

    CERN Multimedia

    Leake, J

    2003-01-01

    BRITAIN is to back a project to build the world's biggest telescope - so powerful that it could see life-bearing planets in other solar systems. It will need the largest mirror ever built at about 100 metres in diameter (1/2 page).

  11. Push-To Telescope Mathematics

    Science.gov (United States)

    Teets, Donald

    2012-01-01

    Two coordinate systems are related here, one defined by the earth's equator and north pole, the other by the orientation of a telescope at some location on the surface of the earth. Applying an interesting though somewhat obscure property of orthogonal matrices and using the cross-product simplifies this relationship, revealing that a surprisingly…

  12. Results from the AMANDA telescope

    CERN Document Server

    Bouhali, O

    2003-01-01

    We present results from the AMANDA high energy neutrino telescope located at the South Pole. They include measurements of the atmospheric neutrino flux, search for UHE point sources, and diffuse sources producing electromagnetic/hadronic showers at the detector or close to it. (4 refs).

  13. Overdenture dengan Pegangan Telescopic Crown

    Directory of Open Access Journals (Sweden)

    Pambudi Santoso

    2014-06-01

    Full Text Available Kaitan presisi merupakan alat retensi mekanis yang menghubungkan antara satu atau lebih pegangan gigi tiruan, yang bertujuan untuk menambah retensi dan/atau stabilisasi. Kaitan presisi dapat digunakan secara luas pada gigi tiruan cekat, gigi tiruan sebagian lepasan, overdenture, implant untuk retensi overdenture, dan protesa maksilo fasial. Overdenture dengan kaitan presisi dapat membantu dalam pembagian beban kunyah, meminimalkan trauma pada gigi pegangan dan jaringan lunak, meminimalkan resorbsi tulang, dan meningkatkan estetik dan pengucapan suara. Salah satu jenis dari kaitan presisi adalah telescopic crown, terdiri dari 2 macam mahkota, yaitu mahkota primer yang melekat secara permanen pada gigi penyangga, dan mahkota sekunder yang melekat pada gigi tiruan. Tujuan pemaparan kasus ini adalah untuk memberikan informasi tentang rehabilitasi pasien edentulous sebagian rahang atas dengan telescopic crown..  Pasien wanita berusia 45 tahun datang ke klinik prostodonsia RSGM Prof.Soedomo dengan keluhan ingin dibuatkan gigi tiruan. Pasien kehilangan gigi 11 12 15 16 17 21 22 24 25 26 dan 27 yang diindikasikan untuk pembuatan overdenture gigi tiruan sebagian lepasan (GTS kerangka logam dengan pegangan telescopic crown pada gigi 13 dan 14 dengan sistem parallel-sided crown. Tahap-tahap pembuatan telescopic crown yaitu mencetak model study dengan catatan gigit pendahuluan. Perawatan saluran dilakukan pada akar gigi 13, dilanjutkan pemasangan pasak fiber serta rewalling dinding bukal. Gigi 13 dan 14 dilakukan preparasi mahkota penuh, dilanjutkan dengan pencetakan model kerja untuk coping primer dan kerangka logam dengan metode double impression. Coping primer disementasi pada gigi penyangga, dilanjutkan pasang coba coping sekunder beserta kerangka logam. Selanjutnya dilakukan pencatatan gigit, pencetakan model kerja, penyusunan gigi dan pasang coba penyusunan gigi pada pasien. Prosedur dilanjutkan dengan proses di laboratorium, serta insersi pada

  14. The Stellar Mass Functions of the CLASH-VLT Clusters MACS J1206-0847 and Abell 209

    Science.gov (United States)

    Annunziatella, M.; Biviano, A.; Mercurio, A.; Nonino, M.; Rosati, P.; Balestra, I.; Girardi, M.; Grillo, C.

    The study of the galaxy stellar mass function, and in particular its dependence from the environment, represents a key observable to discriminate between different models of galaxy evolution. We determined the stellar mass function (SMF) of passive and star-forming (SF) galaxies in different regions of two clusters in the CLASH-VLT sample, MACS J1206.2-0847 and Abell 209. Since these two clusters are at different redshifts, the comparison between the results obtained in the two cases can inform us about the evolution of the SMF with cosmic time.

  15. VLT optical observations of V821 Ara(=GX339-4) in an extended "off" state

    CERN Document Server

    Shahbaz, T; Charles, P A

    2001-01-01

    We report on low-resolution spectroscopy of GX339-4 during its current, extended X-ray `off' state in May 2000 (r=20.1) obtained with the VLT Focal Reducer/low dispersion Spectrograph (FORS1). Although we do not positively detect the secondary star in GX339-4 we place an upper limit of 30 percent on the contribution of a ``normal'' K-type secondary star spectrum to the observed flux. Using this limit for the observed magnitude of the secondary star, we find a lower limit for the distance of GX339-4 to be 5.6 kpc.

  16. NGC 6302: high-ionization permitted lines. Applying X-SSN synthesis to VLT-UVES spectra

    CERN Document Server

    Pequignot, Daniel; Casassus, Simon

    2011-01-01

    A preliminary VLT-UVES spectrum of NGC 6302 (Casassus et al. 2002, MN), which hosts one of the hottest PN nuclei known (Teff ~ 220000 K; Wright et al. 2011, MN), has been recently analysed by means of X-SSN, a spectrum synthesis code for nebulae (Morisset and P\\'equignot). Permitted recombination lines from highly-ionized species are detected/identified for the first time in a PN, and some of them probably for the first time in (Astro)Physics. The need for a homogeneous, high signal-to-noise UVES spectrum for NGC 6302 is advocated.

  17. Using fear appeals in warning labels to promote responsible gambling among VLT players: the key role of depth of information processing.

    Science.gov (United States)

    Munoz, Yaromir; Chebat, Jean-Charles; Suissa, Jacob Amnon

    2010-12-01

    Video lottery terminals (VLT) are a highly lucrative gambling format, but at the same time they are among the most hazardous. Previous research has shown that threatening warnings may be an appropriate approach for promoting protective behavior. The present study explores the potential benefits of threatening warnings in the fight against compulsive gambling. A 4 × 2 factorial design experiment was used to test our model based on both Elaboration Likelihood Model and Protection Motivation Theory. 258 VLT adult players (58% males, 42% females) with various degrees of problem gambling were exposed to three threat levels (plus a control condition) from two different sources (i.e., either a medical source or a source related to the provider of VLT's). Our results show that both higher threat warnings and the medical source of warnings enhance Depth of Information Processing. It was also found that Depth of Information Processing affects positively attitude change and compliance intentions. The theoretical and managerial implications are discussed.

  18. New Control Software of the 188cm Telescope of Okayama Astrophysical Observatory

    Science.gov (United States)

    Yoshida, Michitoshi; Shimizu, Yasuhiro; Watanabe, Etsuji; Yanagisawa, Kenshi; Uraguchi, Fumihiro

    2002-12-01

    We developed the telescope control software for the 188cm telescope of Okayama Astrophysical Observatory (OAO) based on Java technology. Basically, the software consists of two processes running on separate Java virtual machines; one of which is the "Command Dispatcher (CD)" and the other is the "User Interface (UI)". Among the two, CD is the main engine/server of the telescope control, whereas UI is just a client. The "standard" UI we provide is a graphical user interface written in Java/Swing. CD communicates with the local control units (LCUs) of the telescope through RS232C. CD is a Java multi-thread program, in which a number of threads run simultaneously. The threads running in CD are the follows: UNIX socket servers for external communications, socket opener for on-demand open/close of a socket port, socket client manager, auto-guider and dome watcher, internal command dispatcher, status manager, status collector, RS232C writer and reader, logger, and control units. The above "control units" are software models ("objects") of the telescope system. We introduced four control units- "Telescope", "Dome", "Weather-Monitor", and "Pointing"- for telescope control. The first three units are simple software models of the real-worlds devices. The last one, "Pointing", is a unit which abstracts pointing procedure of the telescope. CD and UI communicate with each other using UNIX socket. The command protocol of this communication is fairly simple, and observation instruments, auto guider, or additional UI for remote observation are also able to communicate with CD through socket using this protocol. CD opens and closes socket ports for communication on demand according to the request of client process (UI, instruments etc.), so that any clients can be connected to CD dynamically.

  19. The automated Palomar 60 inch telescope

    OpenAIRE

    Cenko, S Bradley; Fox, Derek B.; Moon, Dae-Sik; Harrison, Fiona A.; Kulkarni, S.R.; Henning, John R.; Guzman, C. Dani; Bonati, Marco; Smith, Roger M.; Thicksten, Robert P.; Doyle, Michael W.; Petrie, Hal L.; Gal-Yam, Avishay; Soderberg, Alicia M.; Anagnostou, Nathaniel L.

    2006-01-01

    We have converted the Palomar 60-inch telescope (P60) from a classical night assistant-operated telescope to a fully robotic facility. The automated system, which has been operational since September 2004, is designed for moderately fast (t

  20. Alignment of the James Webb Space Telescope optical telescope element

    Science.gov (United States)

    Glassman, Tiffany; Levi, Joshua; Liepmann, Till; Hahn, Walter; Bisson, Gary; Porpora, Dan; Hadjimichael, Theo

    2016-07-01

    The optical telescope element (OTE) of the James Webb Space Telescope has now been integrated and aligned. The OTE comprises the flight mirrors and the structure that supports them - 18 primary mirror segments, the secondary mirror, and the tertiary and fine steering mirrors (both housed in the aft optics subsystem). The primary mirror segments and the secondary mirror have actuators to actively control their positions during operations. This allows the requirements for aligning the OTE subsystems to be in the range of microns rather than nanometers. During OTE integration, the alignment of the major subsystems of the OTE structure and optics were controlled to ensure that, when the telescope is on orbit and at cryogenic temperatures, the active mirrors will be within the adjustment range of the actuators. Though the alignment of this flagship mission was complex and intricate, the key to a successful integration process turned out to be very basic: a clear, concise series of steps employing advanced planning, backup measurements, and cross checks that this multi-organizational team executed with a careful and methodical approach. This approach was not only critical to our own success but has implications for future space observatories.

  1. Origins Space Telescope: Telescope Design and Instrument Specifications

    Science.gov (United States)

    Meixner, Margaret; Carter, Ruth; Leisawitz, David; Dipirro, Mike; Flores, Anel; Staguhn, Johannes; Kellog, James; Roellig, Thomas L.; Melnick, Gary J.; Bradford, Charles; Wright, Edward L.; Zmuidzinas, Jonas; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey. The renaming of the mission reflects Origins science goals that will discover and characterize the most distant galaxies, nearby galaxies and the Milky Way, exoplanets, and the outer reaches of our Solar system. This poster will show the preliminary telescope design that will be a large aperture (>8 m in diameter), cryogenically cooled telescope. We will also present the specifications for the spectrographs and imagers over a potential wavelength range of ~10 microns to 1 millimeter. We look forward to community input into this mission definition over the coming year as we work on the concept design for the mission. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. We welcome you to contact the Science and Technology Definition Team (STDT) with your science needs and ideas by emailing us at firsurveyor_info@lists.ipac.caltech.edu.

  2. The Medium Size Telescopes of the Cherenkov Telescope Array

    CERN Document Server

    Pühlhofer, G

    2016-01-01

    The Cherenkov Telescope Array (CTA) is the planned next-generation instrument for ground-based gamma-ray astronomy, covering a photon energy range of ~20 GeV to above 100 TeV. CTA will consist of the order of 100 telescopes of three sizes, installed at two sites in the Northern and Southern Hemisphere. This contribution deals with the 12 meter Medium Size Telescopes (MST) having a single mirror (modified Davies-Cotton, DC) design. In the baseline design of the CTA arrays, 25 MSTs in the South and 15 MSTs in the North provide the necessary sensitivity for CTA in the core energy range of 100 GeV to 10 TeV. DC-MSTs will be equipped with photomultiplier (PMT)-based cameras. Two options are available for these focal plane instruments, that will be provided by the FlashCam and the NectarCAM sub-consortia. In this contribution, a short introduction to the projects and their status is given.

  3. The Principles of Astronomical Telescope Design

    CERN Document Server

    Cheng, Jingquan

    2009-01-01

    Presents a summary of the author's twenty five years of experience in telescope design. This work provides a general introduction to various aspects of telescope design. It discusses the theory behind telescope design. It covers Radio, Infrared, Optical, X-Ray and Gamma-Ray wavelengths

  4. The Hubble Space Telescope: Problems and Solutions.

    Science.gov (United States)

    Villard, Ray

    1990-01-01

    Presented is the best understanding of the flaw discovered in the optics of the Hubble Space Telescope and the possible solutions to the problems. The spherical aberration in the telescope's mirror and its effect on the quality of the telescope's imaging ability is discussed. (CW)

  5. CFRP lightweight structures for extremely large telescopes

    DEFF Research Database (Denmark)

    Jessen, Niels Christian; Nørgaard-Nielsen, Hans Ulrik; Schroll, J.

    2008-01-01

    Telescope structures are traditionally built out of steel. To improve the possibility of realizing the ambitious extremely large telescopes, materials with a higher specific stiffness and a lower coefficient of thermal expansion are needed. An important possibility is Carbon Fibre Reinforced...... Plastic (CFRP). The advantages of using CFRP for the secondary mirror support structure of the European overwhelmingly large telescope are discussed....

  6. Engineering aspects of the Large Binocular Telescope Observatory adaptive optics systems

    Science.gov (United States)

    Brusa, Guido; Ashby, Dave; Christou, Julian C.; Kern, Jonathan; Lefebvre, Michael; McMahon, Tom J.; Miller, Douglas; Rahmer, Gustavo; Sosa, Richard; Taylor, Gregory; Vogel, Conrad; Zhang, Xianyu

    2016-07-01

    Vertical profiles of the atmospheric optical turbulence strength and velocity is of critical importance for simulating, designing, and operating the next generation of instruments for the European Extremely Large Telescope. Many of these instruments are already well into the design phase meaning these profies are required immediately to ensure they are optimised for the unique conditions likely to be observed. Stereo-SCIDAR is a generalised SCIDAR instrument which is used to characterise the profile of the atmospheric optical turbulence strength and wind velocity using triangulation between two optical binary stars. Stereo-SCIDAR has demonstrated the capability to resolve turbulent layers with the required vertical resolution to support wide-field ELT instrument designs. These high resolution atmospheric parameters are critical for design studies and statistical evaluation of on-sky performance under real conditions. Here we report on the new Stereo-SCIDAR instrument installed on one of the Auxillary Telescope ports of the Very Large Telescope array at Cerro Paranal. Paranal is located approximately 20 km from Cerro Armazones, the site of the E-ELT. Although the surface layer of the turbulence will be different for the two sites due to local geography, the high-altitude resolution profiles of the free atmosphere from this instrument will be the most accurate available for the E-ELT site. In addition, these unbiased and independent profiles are also used to further characterise the site of the VLT. This enables instrument performance calibration, optimisation and data analysis of, for example, the ESO Adaptive Optics facility and the Next Generation Transit Survey. It will also be used to validate atmospheric models for turbulence forecasting. We show early results from the commissioning and address future implications of the results.

  7. Design Study of an 8 Meter Monolithic Mirror UV/Optical Space Telescope

    Science.gov (United States)

    Stahl, H. Philip

    2008-01-01

    This paper will review a recent NASA MSFC preliminary study that demonstrated the feasibility of launching a 6 to 8 meter class monolithic primary mirror telescope to Sun-Earth L2 using an Ares V. The study started with the unique capabilities of the Ares V vehicle and examined the feasibility of launching a large aperture low cost low risk telescope based on a conventional ground based glass primary mirror. Specific technical areas studied included optical design; structural design/analysis including primary mirror support structure, sun shade and secondary mirror support structure; thermal analysis; launch vehicle performance and trajectory; spacecraft including structure, propulsion, GN & C, avionics, power systems and reaction wheels; operations & servicing, mass budget and system cost. The study telescope was an on-axis three-mirror anastigmatic design with a fine steering mirror. The observatory has a 100 arc-minute (8.4 X 12 arc-minutes) of diffraction limited field of view at a wavelength les than 500 nm. The study assumed that the primary mirror would be fabricated from an existing Schott Zerodur residual VLT blank edged to 6.2 meters, 175 mm thick at the edge with a mass of 11,000 kg. The entire mass budget for the observatory including primary mirror, structure, light baffle tube, instruments, space craft, avionics, etc. is less than 40,000 kg - a 33% mass margin on the Ares V's 60,000 kg Sun-Earth L2 capability. An 8 meter class observatory would have a total mass of less than 60,000 kg of which the primary mirror is the largest contributor.

  8. Design and implementation of a general main axis controller for the ESO telescopes

    Science.gov (United States)

    Sandrock, Stefan; Di Lieto, Nicola; Pettazzi, Lorenzo; Erm, Toomas

    2012-09-01

    Most of the real-time control systems at the existing ESO telescopes were developed with "traditional" methods, using general purpose VMEbus electronics, and running applications that were coded by hand, mostly using the C programming language under VxWorks. As we are moving towards more modern design methods, we have explored a model-based design approach for real-time applications in the telescope area, and used the control algorithm of a standard telescope main axis as a first example. We wanted to have a clear work-flow that follows the "correct-by-construction" paradigm, where the implementation is testable in simulation on the development host, and where the testing time spent by debugging on target is minimized. It should respect the domains of control, electronics, and software engineers in the choice of tools. It should be a targetindependent approach so that the result could be deployed on various platforms. We have selected the Mathworks tools Simulink, Stateflow, and Embedded Coder for design and implementation, and LabVIEW with NI hardware for hardware-in-the-loop testing, all of which are widely used in industry. We describe how these tools have been used in order to model, simulate, and test the application. We also evaluate the benefits of this approach compared to the traditional method with respect to testing effort and maintainability. For a specific axis controller application we have successfully integrated the result into the legacy platform of the existing VLT software, as well as demonstrated how to use the same design for a new development with a completely different environment.

  9. The Great Observatories Origins Deep Survey VLT/FORS2 Spectroscopy in the GOODS-South Field: Part II

    CERN Document Server

    Vanzella, E; Dickinson, M; Kuntschner, H; Nonino, M; Rettura, A; Rosati, P; Vernet, J; Césarsky, C J; Ferguson, H C; Fosbury, R A E; Giavalisco, M; Haase, J; Moustakas, L A; Popesso, P; Renzini, A; Stern, D; Team, the GOODS

    2006-01-01

    We present the second campaign of the ESO/GOODS program of spectroscopy of faint galaxies in the Chandra Deep Field South (CDF-S). Objects were selected as candidates for VLT/FORS2 observations primarily based on the expectation that the detection and measurement of their spectral features would benefit from the high throughput and spectral resolution of FORS2. The reliability of the redshift estimates is assessed using diagnostic diagrams and comparing the results with public data. 807 spectra of 652 individual targets have been obtained in service mode with the FORS2 spectrograph at the ESO/VLT, providing 501 redshift determinations. The typical redshift uncertainty is estimated to be sigma_z ~ 0.0009. Galaxies have been color selected in a way that the resulting redshift distribution typically spans two redshift domains: from z=0.5 to 2 and z=3.5 to 6.2. In particular, 94 B435-,V606-,i775-"dropout" Lyman break galaxies have been observed, yielding redshifts for 64 objects in the interval 3.4

  10. CLASH-VLT: Substructure in the galaxy cluster MACS J1206.2-0847 from kinematics of galaxy populations

    CERN Document Server

    Girardi, M; Balestra, I; Nonino, M; Biviano, A; Grillo, C; Rosati, P; Annunziatella, M; Demarco, R; Fritz, A; Gobat, R; Lemze, D; Presotto, V; Scodeggio, M; Tozzi, P; Caminha, G Bartosch; Brescia, M; Coe, D; Kelson, D; Koekemoer, A; Lombardi, M; Medezinski, E; Postman, M; Sartoris, B; Umetsu, K; Zitrin, A; Boschin, W; Czoske, O; De Lucia, G; Kuchner, U; Maier, C; Meneghetti, M; Monaco, P; Monna, A; Munari, E; Seitz, S; Verdugo, M; Ziegler, B

    2015-01-01

    In the effort to understand the link between the structure of galaxy clusters and their galaxy populations, we focus on MACS J1206.2-0847, at z~0.44, probing its substructure in the projected phase space through the spectrophotometric properties of a large number of galaxies from the CLASH-VLT survey. Our analysis is mainly based on an extensive spectroscopic dataset of 445 member galaxies, mostly acquired with VIMOS@VLT as part of our ESO Large Programme, sampling the cluster out to a radius ~2R200 (4 Mpc). We classify 412 galaxies as: passive, with strong Hdelta absorption (red and blue ones), and with emission lines from weak to very strong ones. A number of tests for substructure detection is applied to analyze the galaxy distribution in the velocity space, in the 2D space, and in the (3D) projected phase-space. Studied in its entirety, the cluster appears as a large-scale relaxed system with a few, secondary, minor overdensities in 2D distribution. We detect no velocity gradient or evidence of deviations...

  11. Is Fear to Intervene with Problem Gamblers Related to Interveners' Gender and Status? A Study with VLT Operators.

    Science.gov (United States)

    Tomei, Alexander; Zumwald, Coralie

    2017-03-01

    We assess how video lottery terminal (VLT) operators' self-perceive their ability to recognize a problem gambler, to what extent they are approached by problem gamblers seeking for assistance, how many detections and interventions they report, and the reasons they give for not intervening with clients who show signs of problem gambling. We also examine how these variables are related to the operators' gender and status in the establishment. 177 VLT operators anonymously completed a structured questionnaire at the beginning of a responsible gambling training class held in different French-speaking Swiss towns. The operators felt confident in their ability to detect problem gambling behaviors, were rarely approached by problem gamblers seeking assistance, and reported fewer interventions compared to the number of detections. This reluctance to intervene was mainly attributed to the fear of potential negative reactions from the client. Female staff were the most reluctant to intervene and the most fearful of potential negative reactions from the client. Responsible gambling training programs should include coping strategies for dealing with potential negative reactions from clients. Our findings suggest that staff gender and status are two individual characteristics that should be taken into account when planning responsible gambling trainings.

  12. CLASH-VLT: Strangulation of cluster galaxies in MACSJ0416.1-2403 as seen by their chemical enrichment

    CERN Document Server

    Maier, C; Ziegler, B L; Verdugo, M; Balestra, I; Girardi, M; Mercurio, A; Rosati, P; Fritz, A; Grillo, C; Nonino, M; Sartoris, B

    2016-01-01

    (abridged) We explore the Frontier Fields cluster MACS J0416.1-2403 at z=0.3972 with VIMOS/VLT spectroscopy from the CLASH-VLT survey covering a region which corresponds to almost three virial radii. We measure fluxes of 5 emission lines of 76 cluster members enabling us to unambiguously derive O/H gas metallicities, and also SFRs from Halpha. For intermediate massses we find a similar distribution of cluster and field galaxies in the MZR and mass vs. sSFR diagrams. Bulge-dominated cluster galaxies have on average lower sSFRs and higher O/Hs compared to their disk-dominated counterparts. We use the location of galaxies in the projected velocity vs. position phase-space to separate our cluster sample into a region of objects accreted longer time ago and a region of recently accreted and infalling galaxies. We find a higher fraction of accreted metal-rich galaxies (63%) compared to the fraction of 28% of metal-rich galaxies in the infalling regions. Intermediate mass galaxies falling into the cluster for the fi...

  13. VLT identification of the optical afterglow of the gamma-ray burst GRB000131 at z=4.50

    DEFF Research Database (Denmark)

    Andersen, M.I.; Hjorth, J.; Jesen, B.L.

    2000-01-01

    Angstrom. This places GRB 000131 at a redshift of 4.500 +/- 0.015. The inferred isotropic energy release in gamma rays alone was similar to 10(54) erg (depending on the assumed cosmology). The rapid power-law decay of the afterglow (index alpha = 2.25, similar to bursts with a prior break in the lightcurve......We report the discovery of the gamma-ray burst GRB 000131 and its optical afterglow. The optical identification was made with the VLT 84 hours after the burst following a BATSE detection and an Inter Planetary Network localization. GRB 000131 was a bright, long-duration GRB, with an apparent...... precursor signal 62 s prior to trigger. The afterglow was detected in ESO VLT, NTT, and DK1.54m follow-up observations. Broad-band and spectroscopic observations of the spectral energy distribution reveals a sharp break at optical wavelengths which is interpreted as a Ly alpha absorption edge at 6700...

  14. VLT identification of the optical afterglow of the gamma-ray burst GRB 000131 at z=4.50

    DEFF Research Database (Denmark)

    Andersen, M.I.; Hjorth, J.; Pedersen, H.

    2000-01-01

    Angstrom. This places GRB 000131 at a redshift of 4.500 +/- 0.015. The inferred isotropic energy release in gamma rays alone was similar to 10(54) erg (depending on the assumed cosmology). The rapid power-law decay of the afterglow (index alpha = 2.25, similar to bursts with a prior break in the lightcurve......We report the discovery of the gamma-ray burst GRB 000131 and its optical afterglow. The optical identification was made with the VLT 84 hours after the burst following a BATSE detection and an Inter Planetary Network localization. GRB 000131 was a bright, long-duration GRB, with an apparent...... precursor signal 62 s prior to trigger. The afterglow was detected in ESO VLT, NTT, and DK1.54m follow-up observations. Broad-band and spectroscopic observations of the spectral energy distribution reveals a sharp break at optical wavelengths which is interpreted as a Ly alpha absorption edge at 6700...

  15. VLT identification of the optical afterglow of the gamma-ray burst GRB 000131 at z=4.50

    DEFF Research Database (Denmark)

    Andersen, M.I.; Hjorth, J.; Pedersen, H.

    2000-01-01

    Angstrom. This places GRB 000131 at a redshift of 4.500 +/- 0.015. The inferred isotropic energy release in gamma rays alone was similar to 10(54) erg (depending on the assumed cosmology). The rapid power-law decay of the afterglow (index alpha = 2.25, similar to bursts with a prior break in the lightcurve......We report the discovery of the gamma-ray burst GRB 000131 and its optical afterglow. The optical identification was made with the VLT 84 hours after the burst following a BATSE detection and an Inter Planetary Network localization. GRB 000131 was a bright, long-duration GRB, with an apparent...... precursor signal 62 s prior to trigger. The afterglow was detected in ESO VLT, NTT, and DK1.54m follow-up observations. Broad-band and spectroscopic observations of the spectral energy distribution reveals a sharp break at optical wavelengths which is interpreted as a Ly alpha absorption edge at 6700...

  16. VLT identification of the optical afterglow of the gamma-ray burst GRB000131 at z=4.50

    DEFF Research Database (Denmark)

    Andersen, M.I.; Hjorth, J.; Jesen, B.L.

    2000-01-01

    Angstrom. This places GRB 000131 at a redshift of 4.500 +/- 0.015. The inferred isotropic energy release in gamma rays alone was similar to 10(54) erg (depending on the assumed cosmology). The rapid power-law decay of the afterglow (index alpha = 2.25, similar to bursts with a prior break in the lightcurve......We report the discovery of the gamma-ray burst GRB 000131 and its optical afterglow. The optical identification was made with the VLT 84 hours after the burst following a BATSE detection and an Inter Planetary Network localization. GRB 000131 was a bright, long-duration GRB, with an apparent...... precursor signal 62 s prior to trigger. The afterglow was detected in ESO VLT, NTT, and DK1.54m follow-up observations. Broad-band and spectroscopic observations of the spectral energy distribution reveals a sharp break at optical wavelengths which is interpreted as a Ly alpha absorption edge at 6700...

  17. VLT identification of the optical afterglow of the gamma-ray burst GRB 000131 at z=4.50

    DEFF Research Database (Denmark)

    Andersen, M. I.; Hjorth, J.; Pedersen, H.

    2000-01-01

    . This places GRB 000131 at a redshift of 4.500 +/- 0.015. The inferred isotropic energy release in gamma rays alone was approximately 10^54 erg (depending on the assumed cosmology). The rapid power-law decay of the afterglow (index alpha=2.25, similar to bursts with a prior break in the lightcurve), however......We report the discovery of the gamma-ray burst GRB 000131 and its optical afterglow. The optical identification was made with the VLT 84 hours after the burst following a BATSE detection and an Inter Planetary Network localization. GRB 000131 was a bright, long-duration GRB, with an apparent...... precursor signal 62 s prior to trigger. The afterglow was detected in ESO VLT, NTT, and DK1.54m follow-up observations. Broad-band and spectroscopic observations of the spectral energy distribution reveals a sharp break at optical wavelengths which is interpreted as a Ly-alpha absorption edge at 6700 A...

  18. The VLT LBG Redshift Survey - III. The clustering and dynamics of Lyman-break galaxies at z ~ 3

    CERN Document Server

    Bielby, R; Shanks, T; Crighton, N H M; Infante, L; Bornancini, C G; Francke, H; Heraudeau, P; Lambas, D G; Metcalfe, N; Minniti, D; Padilla, N; Theuns, T; Tummuangpak, P; Weilbacher, P

    2012-01-01

    We present a survey of 2,148 galaxy redshifts from the VLT LBG Redshift Survey (VLRS), a spectroscopic survey of z ~ 3 galaxies in wide fields centred on background QSOs made using the VLT VIMOS instrument. To make a definitive LBG clustering analysis, we have combined the VLRS redshifts with the 813 Keck LBG redshifts of Steidel et al, with the statistical power of VLRS at large scales complementing the accuracy of the Keck sample at small scales. From the semi-projected correlation function for the VLRS and combined surveys, we find that the results are well fit with a single power law model for the real space correlation function with clustering scale lengths of respectively r0 = 3.32 \\pm 0.41 and 3.75 \\pm 0.24 Mpc/h. We note that the corresponding combined slope is flatter than for local galaxies at {\\gamma} = 1.55 \\pm 0.09. This flat slope is confirmed by the z-space correlation function and in the range 10 < s < 100 Mpc/h the VLRS shows a 2.5{\\sigma} excess over the {\\Lambda}CDM linear prediction....

  19. Focusing X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab; Juda, Michael; Kolodziejczak, Jeffrey; Murray, Stephen; Petre, Robert; Podgorski, William; Ramsey, Brian; Reid, Paul; Saha, Timo; Wolk, Scott; Troller-McKinstry, Susan; Weisskopf, Martin; Wilke, Rudeger; Zhang, William

    2010-01-01

    During the half-century history of x-ray astronomy, focusing x-ray telescopes, through increased effective area and finer angular resolution, have improved sensitivity by 8 orders of magnitude. Here, we review previous and current x-ray-telescope missions. Next, we describe the planned next-generation x-ray-astronomy facility, the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility, Generation X. Its scientific objectives will require very large areas (about 10,000 sq m) of highly-nested, lightweight grazing-incidence mirrors, with exceptional (about 0.1-arcsec) resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.

  20. The Ortega Telescope Andor CCD

    Science.gov (United States)

    Tucker, M.; Batcheldor, D.

    2012-07-01

    We present a preliminary instrument report for an Andor iKon-L 936 charge-couple device (CCD) being operated at Florida Tech's 0.8 m Ortega Telescope. This camera will replace the current Finger Lakes Instrumentation (FLI) Proline CCD. Details of the custom mount produced for this camera are presented, as is a quantitative and qualitative comparison of the new and old cameras. We find that the Andor camera has 50 times less noise than the FLI, has no significant dark current over 30 seconds, and has a smooth, regular flat field. The Andor camera will provide significantly better sensitivity for direct imaging programs and, once it can be satisfactorily tested on-sky, will become the standard imaging device on the Ortega Telescope.

  1. Telescoping phenomenon in pathological gambling

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Mooney, Marc E

    2012-01-01

    The course of pathological gambling (PG) in women has been described as having a later age of initiation but a shorter time to problematic gambling ("telescoped"). This study examined evidence for telescoping and its relationship with comorbidities. Seventy-one treatment-seeking individuals with PG...... underwent a diagnostic interview to examine gambling behaviors, age at initiation of gambling, and time from initiation to meeting criteria for PG. The women had a higher mean age at gambling initiation compared with that of the men (mean [SD] age, 31.3 [13.0] years, compared with 22.4 [7.9] years; p = 0...... and suggests a need for greater clinical focus on the gender differences of gambling behavior....

  2. Cherenkov Telescope Array Data Management

    CERN Document Server

    Lamanna, G; Contreras, J L; Knödlseder, J; Kosack, K; Neyroud, N; Aboudan, A; Arrabito, L; Barbier, C; Bastieri, D; Boisson, C; Brau-Nogué, S; Bregeon, J; Bulgarelli, A; Carosi, A; Costa, A; De Cesare, G; Reyes, R de los; Fioretti, V; Gallozzi, S; Jacquemier, J; Khelifi, B; Kocot, J; Lombardi, S; Lucarelli, F; Lyard, E; Maier, G; Massimino, P; Osborne, J P; Perri, M; Rico, J; Sanchez, D A; Satalecka, K; Siejkowski, H; Stolarczyk, T; Szepieniec, T; Testa, V; Walter, R; Ward, J E; Zoli, A

    2015-01-01

    Very High Energy gamma-ray astronomy with the Cherenkov Telescope Array (CTA) is evolving towards the model of a public observatory. Handling, processing and archiving the large amount of data generated by the CTA instruments and delivering scientific products are some of the challenges in designing the CTA Data Management. The participation of scientists from within CTA Consortium and from the greater worldwide scientific community necessitates a sophisticated scientific analysis system capable of providing unified and efficient user access to data, software and computing resources. Data Management is designed to respond to three main issues: (i) the treatment and flow of data from remote telescopes; (ii) "big-data" archiving and processing; (iii) and open data access. In this communication the overall technical design of the CTA Data Management, current major developments and prototypes are presented.

  3. Highlights from the Telescope Array

    Directory of Open Access Journals (Sweden)

    Matthews J.N.

    2016-01-01

    Full Text Available The Telescope Array measures the properties of ultra high energy cosmic ray induced extensive air showers. We do this using a variety of techniques including an array of scintillator detectors to sample the footprint of the air shower when it reaches the Earth’s surface and telescopes to measure the fluorescence and Cerenkov light of the air shower. From this we determine the energy spectrum and chemical composition of the primary particles. We also search for sources of cosmic rays and anisotropy. We have found evidence of a possible source of ultra high energy cosmic rays in the northern sky. The experiment and its most recent measurements will be discussed.

  4. The LWA1 Radio Telescope

    CERN Document Server

    Ellingson, S W; Craig, J; Hartman, J; Dowell, J; Wolfe, C N; Clarke, T E; Hicks, B C; Kassim, N E; Ray, P S; Rickard, L J; Schinzel, F K; Weiler, K W

    2012-01-01

    LWA1 is a new radio telescope operating in the frequency range 10-88 MHz, located in central New Mexico. The telescope consists of 258 pairs of dipole-type antennas whose outputs are individually digitized and formed into beams. Simultaneously, signals from all dipoles can be recorded using one of the instrument's "all dipoles" modes, facilitating all-sky imaging. Notable features of the instrument include high intrinsic sensitivity (about 6 kJy zenith system equivalent flux density), large instantaneous bandwidth (up to 78 MHz), and 4 independently-steerable beams utilizing digital "true time delay" beamforming. This paper summarizes the design of LWA1 and its performance as determined in commissioning experiments. We describe the method currently in use for array calibration, and report on measurements of sensitivity and beamwidth.

  5. Focusing Telescopes in Nuclear Astrophysics

    CERN Document Server

    Ballmoos, Peter von

    2007-01-01

    This volume is the first of its kind on focusing gamma-ray telescopes. Forty-eight refereed papers provide a comprehensive overview of the scientific potential and technical challenges of this nascent tool for nuclear astrophysics. The book features articles dealing with pivotal technologies such as grazing incident mirrors, multilayer coatings, Laue- and Fresnel-lenses - and even an optic using the curvature of space-time. The volume also presents an overview of detectors matching the ambitious objectives of gamma ray optics, and facilities for operating such systems on the ground and in space. The extraordinary scientific potential of focusing gamma-ray telescopes for the study of the most powerful sources and the most violent events in the Universe is emphasized in a series of introductory articles. Practicing professionals, and students interested in experimental high-energy astrophysics, will find this book a useful reference

  6. Education and outreach using the falcon telescope network

    Science.gov (United States)

    Gresham, Kimberlee C.; Palma, Christopher; Polsgrove, Daniel E.; Chun, Francis K.; Della-Rose, Devin J.; Tippets, Roger D.

    2016-12-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. The diversity of the users implies a wide variety of observing interests, and thus the FTN collects images on diverse objects, including satellites, galactic and extragalactic objects, and objects popular for education and public outreach. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA. Currently, there are five Falcon telescopes installed, two in Colorado and one each in Pennsylvania, Chile, and Australia. These five telescopes are in various stages of operational capability but all are remotely operable via a remote desktop application. The FTN team has conducted STEM First Light Projects for three of the U.S. observatories, soliciting proposals from middle and high school students and teachers that suggest and then become what is observed as official STEM first-light objects. Students and teachers learn how to write and submit a proposal as well as how telescopes operate and take data, while university-level students at the U.S. Air Force Academy and The Pennsylvania State University learn how to evaluate proposals and provide feedback to the middle and high school students and teachers. In this paper, we present the current status of the FTN, details of and lessons

  7. The Antares Undersea Neutrino Telescope

    Science.gov (United States)

    Anghinolfi, Marco

    2013-11-01

    Neutrino astronomy is a very promising field of investigation representing a complementary source of information with respect to photon-astronomy. ANTARES, operating off the French Mediterranean coast, is the worlds largest operational underwater neutrino telescope. In these proceedings, in addition to a short detector description, the results of recent analysis will be discussed. The ANTARES project is an important physics experiment but also represents a bench mark for a future large detector of the km3 scale.

  8. Clumpy dust clouds and extended atmosphere of the AGB star W Hydrae revealed with VLT/SPHERE-ZIMPOL and VLTI/AMBER. II. Time variations between pre-maximum and minimum light

    Science.gov (United States)

    Ohnaka, K.; Weigelt, G.; Hofmann, K.-H.

    2017-01-01

    Aims: Our recent visible polarimetric images of the well-studied AGB star W Hya taken at pre-maximum light (phase 0.92) with VLT/SPHERE-ZIMPOL have revealed clumpy dust clouds close to the star at 2 R⋆. We present second-epoch SPHERE-ZIMPOL observations of W Hya at minimum light (phase 0.54) as well as high-spectral resolution long-baseline interferometric observations with the AMBER instrument at the Very Large Telescope Interferometer (VLTI). Methods: We observed W Hya with VLT/SPHERE-ZIMPOL at three wavelengths in the continuum (645, 748, and 820 nm), in the Hα line at 656.3 nm, and in the TiO band at 717 nm. The VLTI/AMBER observations were carried out in the wavelength region of the CO first overtone lines near 2.3 μm with a spectral resolution of 12 000. Results: The high-spatial resolution polarimetric images obtained with SPHERE-ZIMPOL have allowed us to detect clear time variations in the clumpy dust clouds as close as 34-50 mas (1.4-2.0 R⋆) to the star. We detected the formation of a new dust cloud as well as the disappearance of one of the dust clouds detected at the first epoch. The Hα and TiO emission extends to 150 mas ( 6 R⋆), and the Hα images obtained at two epochs reveal time variations. The degree of linear polarization measured at minimum light, which ranges from 13 to 18%, is higher than that observed at pre-maximum light. The power-law-type limb-darkened disk fit to the AMBER data in the continuum results in a limb-darkened disk diameter of 49.1 ± 1.5 mas and a limb-darkening parameter of 1.16 ± 0.49, indicating that the atmosphere is more extended with weaker limb-darkening compared to pre-maximum light. Our Monte Carlo radiative transfer modeling shows that the second-epoch SPHERE-ZIMPOL data can be explained by a shell of 0.1 μm grains of Al2O3, Mg2SiO4, and MgSiO3 with a 550 nm optical depth of 0.6 ± 0.2 and an inner and outer radii of 1.3 R⋆ and 10 ± 2R⋆, respectively. Our modeling suggests the predominance of small (0

  9. Preliminary Results on VLT K-band Imaging Observations of GRB Host Galaxies

    Indian Academy of Sciences (India)

    E. Le Floc’h; I. F. Mirabel; P.-A. Duc

    2002-03-01

    We have obtained -band imaging observations of Gamma-Ray Burst (GRB) host galaxies with the near-infrared spectro-imager ISAAC installed on the Very Large Telescope at Paranal (Chile). The derived magnitudes, combined with other photometric data taken from the literature, are used to investigate the – colors of GRB hosts. We do not find any extremely reddened starbursts in our sample, despite the capability of GRBs to trace star formation even in dusty regions. The observed – colors are on the contrary typical of irregular and spiral blue galaxies at high redshift.

  10. VLT DSM, the control system of the largest deformable secondary mirror ever manufactured

    Science.gov (United States)

    Manetti, Mauro; Morandini, Marco; Mantegazza, Paolo; Biasi, Roberto; Andrighettoni, Mario; Gallieni, Daniele

    2014-07-01

    A proven technology for the shape control of large secondary deformable mirrors employs a magnetically levitated contactless solution and relies on voice-coil actuators co-located to capacitive position sensors. The present work focuses on the description of the latest upgrade of this technology, as applied to the Very Large Telescope Deformable Secondary Mirror, the largest continuous facesheet adaptive mirror ever manufactured. The controller is based on a completely decentralized high frequency feedback coupled to a lower frequency improved feedforward. The system enhancements and performances are verified through electromechanical tests.

  11. Building the Green Bank Telescope

    Science.gov (United States)

    Kellermann, Kenneth I.

    2017-01-01

    In a previous presentation, I reported on how the freak collapse of the NRAO 300-ft transit radio telescope led to the inclusion of $75 million for a new radio telescope in the 1989 Congressional Emergency Supplemental Appropriations Act. But, this was only the beginning. NRAO was faced with challenging specifications and an unworkable schedule, but there was no design and no project team. Only one bid was even close to the Congressional appropriation. In an attempt to meet the unrealistic antenna delivery date, the contractor started construction of the foundation and fabrication of antenna members before the design was finished, leading to retrofits, redesign, and multiple delays. The antenna contractor was twice sold to other companies leading to further delays and cost escalation. In order to recoup their mounting losses, the new owners sued NRAO for $29 million for claimed design changes, and NRAO countersued demanding to be reimbursed for added project management costs and lost scientific data resulting from the seven-year delay in the completion of the telescope. Legal fees and a small net award in favor of the contractor left NRAO and the NSF with a nine million dollar bill which NSF handled by an innovative accounting adjustment.

  12. Academic Training: Deep Space Telescopes

    CERN Multimedia

    Françoise Benz

    2006-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 20, 21, 22, 23, 24 February from 11:00 to 12:00 - Council Chamber on 20, 21, 23, 24 February, TH Auditorium, bldg 4 - 3-006, on 22 February Deep Space Telescopes G. BIGNAMI / CNRS, Toulouse, F & Univ. di Pavia, I The short series of seminars will address results and aims of current and future space astrophysics as the cultural framework for the development of deep space telescopes. It will then present such new tools, as they are currently available to, or imagined by, the scientific community, in the context of the science plans of ESA and of all major world space agencies. Ground-based astronomy, in the 400 years since Galileo's telescope, has given us a profound phenomenological comprehension of our Universe, but has traditionally been limited to the narrow band(s) to which our terrestrial atmosphere is transparent. Celestial objects, however, do not care about our limitations, and distribute most of the information about their physics thro...

  13. The NASA Spitzer Space Telescope.

    Science.gov (United States)

    Gehrz, R D; Roellig, T L; Werner, M W; Fazio, G G; Houck, J R; Low, F J; Rieke, G H; Soifer, B T; Levine, D A; Romana, E A

    2007-01-01

    The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

  14. QUIJOTE telescope design and fabrication

    Science.gov (United States)

    Gomez, Alberto; Murga, Gaizka; Etxeita, Borja; Sanquirce, Rubén; Rebolo, Rafael; Rubiño-Martin, Jose Alberto; Herreros, José-Miguel; Hoyland, Roger; Gomez, Francisca; Génova-Santos, Ricardo T.; Piccirillo, Lucio; Maffei, Bruno; Watson, Robert

    2010-07-01

    The QUIJOTE CMB experiment aims to characterize the polarization of the CMB in the frequency range 10-30 GHz and large angular scales. It will be installed in the Teide Observatory, following the projects that the Anisotropy of the Cosmic Microwave Background group has developed in the past (Tenerife experiment, IAC-Bartol experiment...) and is running at the present time (VSA, Cosmosomas). The QUIJOTE CMB experiment will consist of two telescopes which will be installed inside a unique enclosure, which is already constructed. The layout of both telescopes is based on an altazimuth mount supporting a primary and a secondary mirror disposed in a offset Gregorian Dragon scheme. The use of industrial-like fabrication techniques, such as sand-mould casting, CNC machining, and laser tracker measuring for alignment, provided the required performances for microwave observation. A fast-track construction scheme, altogether with the use of these fabrication techniques allowed designing and manufacturing the opto-mechanics of the telescope in 14 months prior to delivery for final start-up in December 2008.

  15. Hard X-ray Modulation Telescope

    Institute of Scientific and Technical Information of China (English)

    LU Fangjun

    2011-01-01

    The Hard X-ray Modulation Telescope (HXMT) will be China's first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm^2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm^2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 384 cm^2).

  16. Educational activities with the Faulkes Telescopes

    Science.gov (United States)

    Roberts, S.; Roche, P.; Ross, R.

    2008-06-01

    Las Cumbres Observatory Global Telescope Network (LCOGTN) will eventually provide access to a global network of robotic telescopes for research-based science education. Here we present the educational projects that have been undertaken using the 2-m Faulkes Telescopes in Hawaii and Australia in both the UK and Europe. These include themed observing days in which schools collaborate in their telescope sessions, the development of science portals where schools can upload and share their telescope data, and other innovative projects. Public access to these facilities will increase as IYA2009 approaches.

  17. A shift in Jupiter's equatorial haze distribution imaged with the Multi-Conjugate Adaptive Optics Demonstrator at the VLT

    CERN Document Server

    Wong, Michael H; Marchetti, Enrico; Amico, Paola; Tordo, Sebastien; Bouy, Herve; de Pater, Imke

    2008-01-01

    Jupiter was imaged during the Science Demonstration of the MCAO Demonstrator (MAD) at the European Southern Observatory's UT3 Very Large Telescope unit. Io and Europa were used as natural guide stars on either side of Jupiter, separated from each other by about 1.6 arcmin from 23:41 to 01:32 UT (2008 Aug 16/17). The corrected angular resolution was 0.090 arcsec across the entire field of view, as measured on background stars. The observations at 2.02, 2.14, and 2.16 micrometers were sensitive to portions of the Jovian spectrum with strong methane absorption. The data probe the upper troposphere, which is populated with a fine (~0.5 micrometer) haze. Two haze sources have been proposed: lofting of fine cloud particles into the stable upper troposphere, and condensation of hydrazine produced via ammonia photochemistry. The upper tropospheric haze is enhanced over Jupiter's equatorial region. Dramatic changes in the underlying cloud cover--part of the 2006/2007 "global upheaval"--may be associated with changes i...

  18. Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

    Science.gov (United States)

    1999-11-01

    Today the HST Archives contain more than 260 000 astronomical observations. More than 13 000 astronomical objects have been observed by hundreds of different groups of scientists. Direct proof of the scientific significance of this project is the record-breaking number of papers published : over 2400 to date. Some of HST's most memorable achievements are: * the discovery of myriads of very faint galaxies in the early Universe, * unprecedented, accurate measurements of distances to the farthest galaxies, * significant improvement in the determination of the Hubble constant and thus the age of the Universe, * confirmation of the existence of blacks holes, * a far better understanding of the birth, life and death of stars, * a very detailed look at the secrets of the process by which planets are created. Europe and HST ESA's contribution to HST represents a nominal investment of 15%. ESA provided one of the two imaging instruments - the Faint Object Camera (FOC) - and the solar panels. It also has 15 scientists and computer staff working at the Space Telescope Science Institute in Baltimore (Maryland). In Europe the astronomical community receives observational assistance from the Space Telescope European Coordinating Facility (ST-ECF) located in Garching, Munich. In return for ESA's investment, European astronomers have access to approximately 15% of the observing time. In reality the actual observing time competitively allocated to European astronomers is closer to 20%. Looking back at almost ten years of operation, the head of ST-ECF, European HST Project Scientist Piero Benvenuti states: "Hubble has been of paramount importance to European astronomy, much more than the mere 20% of observing time. It has given the opportunity for European scientists to use a top class instrument that Europe alone would not be able to build and operate. In specific areas of research they have now, mainly due to HST, achieved international leadership." One of the major reasons for

  19. Computer simulations of interferometric imaging with the VLT interferometer and its AMBER instrument

    CERN Document Server

    Przygodda, F; Hofmann, Karl Heinrich; Weigelt, G

    2001-01-01

    We present computer simulations of interferometric imaging with the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory (ESO) and the Astronomical MultiBEam Recombiner (AMBER) phase-closure instrument. These simulations include both the astrophysical modelling of a stellar object by radiative transfer calculations and the simulation of light propagation from the object to the detector (through atmosphere, telescopes, and the AMBER instrument), simulation of photon noise and detector read-out noise, and finally data processing of the interferograms. The results show the dependence of the visibility error bars on the following observational parameters: different seeing during the observation of object and reference star (Fried parameters r_0,object and r_0,ref ranging between 0.9m and 1.2m), different residual tip-tilt error (delta_tt,object and delta_tt,ref ranging between 0.1% and 20% of the Airy disk diameter), and object brightness (K_object=0.7mag to 10.2mag, K_ref=0.7mag). Exem...

  20. A treatment procedure for VLT/SINFONI data cubes: application to NGC 5643

    CERN Document Server

    Menezes, R B; Ricci, T V; Steiner, J E; May, D; Borges, B W

    2015-01-01

    In this second paper of a series, we present a treatment procedure for data cubes obtained with the Spectrograph for Integral Field Observations in the Near Infrared of the Very Large Telescope. We verified that the treatment procedure improves significantly the quality of the images of the data cubes, allowing a more detailed analysis. The images of the Br$\\gamma$ and H$_2 \\lambda 21218$ emission lines from the treated data cube of the nuclear region of NGC 5643 reveal the existence of ionized and molecular-gas clouds around the nucleus, which cannot be seen clearly in the images from the non-treated data cube of this galaxy. The ionized-gas clouds represent the narrow-line region, in the form of a bicone. We observe a good correspondence between the positions of the ionized-gas clouds in the Br$\\gamma$ image and in an [O III] image, obtained with the Hubble Space Telescope, of the nuclear region of this galaxy convolved with an estimate of the point-spread function of the data cube of NGC 5643. The morpholo...

  1. Herschel SPIRE FTS telescope model correction

    CERN Document Server

    Hopwood, Rosalind; Polehampton, Edward T; Valtchanov, Ivan; Benielli, Dominique; Imhof, Peter; Lim, Tanya; Lu, Nanyao; Marchili, Nicola; Pearson, Chris P; Swinyard, Bruce M

    2014-01-01

    Emission from the Herschel telescope is the dominant source of radiation for the majority of SPIRE Fourier transform spectrometer (FTS) observations, despite the exceptionally low emissivity of the primary and secondary mirrors. Accurate modelling and removal of the telescope contribution is, therefore, an important and challenging aspect of FTS calibration and data reduction pipeline. A dust-contaminated telescope model with time invariant mirror emissivity was adopted before the Herschel launch. However, measured FTS spectra show a clear evolution of the telescope contribution over the mission and strong need for a correction to the standard telescope model in order to reduce residual background (of up to 7 Jy) in the final data products. Systematic changes in observations of dark sky, taken over the course of the mission, provide a measure of the evolution between observed telescope emission and the telescope model. These dark sky observations have been used to derive a time dependent correction to the tel...

  2. Aligning Astronomical Telescopes via Identification of Stars

    Science.gov (United States)

    Whorton, Mark

    2010-01-01

    A proposed method of automated, precise alignment of a ground-based astronomical telescope would eliminate the need for initial manual alignment. The method, based on automated identification of known stars and other celestial objects in the telescope field of view, would also eliminate the need for an initial estimate of the aiming direction. The method does not require any equipment other than a digital imaging device such as a charge-coupled-device digital imaging camera and control computers of the telescope and camera, all of which are standard components in professional astronomical telescope systems and in high-end amateur astronomical telescope systems. The method could be implemented in software running in the telescope or camera control computer or in an external computer communicating with the telescope pointing mount and camera control computers.

  3. Recent developments for the Large Binocular Telescope Guiding Control Subsystem

    Science.gov (United States)

    Golota, T.; De La Peña, M. D.; Biddick, C.; Lesser, M.; Leibold, T.; Miller, D.; Meeks, R.; Hahn, T.; Storm, J.; Sargent, T.; Summers, D.; Hill, J.; Kraus, J.; Hooper, S.; Fisher, D.

    2014-07-01

    The Large Binocular Telescope (LBT) has eight Acquisition, Guiding, and wavefront Sensing Units (AGw units). They provide guiding and wavefront sensing capability at eight different locations at both direct and bent Gregorian focal stations. Recent additions of focal stations for PEPSI and MODS instruments doubled the number of focal stations in use including respective motion, camera controller server computers, and software infrastructure communicating with Guiding Control Subsystem (GCS). This paper describes the improvements made to the LBT GCS and explains how these changes have led to better maintainability and contributed to increased reliability. This paper also discusses the current GCS status and reviews potential upgrades to further improve its performance.

  4. Optical and system engineering in the development of a high-quality student telescope kit

    Science.gov (United States)

    Pompea, Stephen M.; Pfisterer, Richard N.; Ellis, Scott; Arion, Douglas N.; Fienberg, Richard Tresch; Smith, Thomas C.

    2010-07-01

    The Galileoscope student telescope kit was developed by a volunteer team of astronomers, science education experts, and optical engineers in conjunction with the International Year of Astronomy 2009. This refracting telescope is in production with over 180,000 units produced and distributed with 25,000 units in production. The telescope was designed to be able to resolve the rings of Saturn and to be used in urban areas. The telescope system requirements, performance metrics, and architecture were established after an analysis of current inexpensive telescopes and student telescope kits. The optical design approaches used in the various prototypes and the optical system engineering tradeoffs will be described. Risk analysis, risk management, and change management were critical as was cost management since the final product was to cost around 15 (but had to perform as well as 100 telescopes). In the system engineering of the Galileoscope a variety of analysis and testing approaches were used, including stray light design and analysis using the powerful optical analysis program FRED.

  5. Progress on Space Solar Telescope in 2002-2004

    Institute of Scientific and Technical Information of China (English)

    AI Guoxiang; YAN Yihua; JIN Shengzhen

    2004-01-01

    The progress on Chinese Space Solar Telescope (SST) in 2002-2004 is introduced. The documentations on plans and outlines based on the standards of Chinese aerospace industry for SST mission has been fulfilled. The key technical problems of SST satellite platform and payloads are tackled during pre-study stage of the mission. The laboratory assembly and calibration of the main optical telescope of 1.2 m spherical mirror and 1 m plain mirror have been carried out with the accuracy of λ/40 and λ/30, respectively. The prototype at 17.1 nm for extreme ultraviolet telescope is under development and manufacture with a diameter of 13 cm. Its primary and secondary mirrors have a manufacturing error of 5nm with a roughness degree of less than 0.5 nm and a multiplayer reflection factor of better than 20%. The on-board scientific data processing unit has been developed. Prototypes for other payloads such as H and white light telescope, wide band spectroscopy in high energy and solar and interplanetary radio spectrometer have been developed accordingly.

  6. An EUDET/AIDA Pixel Beam Telescope for Detector Development

    CERN Document Server

    Rubinskiy, I

    2015-01-01

    A high resolution (σ∼2μm) beam telescope based on monolithic active pixel sensors (MAPS) was developed within the EUDET collaboration. The telescope consists of six monolithic active pixel sensor planes (Mimosa26) with a pixel pitch of 18.4 \\mu m and thinned down to 50 \\mu m. The excellent resolution, readout rate and DAQ integration capabilities made the telescope a primary test beam tool for many groups including several CERN based experiments. Within the European detector infrastructure project AIDA the test beam telescope is being further extended in terms of cooling and powering infrastructure, read-out speed, area of acceptance, and precision. In order to provide a system optimized for the different requirements by the user community a combination of various state-of-the-art pixel technologies is foreseen. Furthermore, new central dead-time-free trigger logic unit (TLU) has been developed to provide LHC-speed response with one-trigger-per-particle operating mode and a synchronous clock for all conn...

  7. The VLT-FLAMES Tarantula Survey. VIII. Multiplicity properties of the O-type star population

    Science.gov (United States)

    Sana, H.; de Koter, A.; de Mink, S. E.; Dunstall, P. R.; Evans, C. J.; Hénault-Brunet, V.; Maíz Apellániz, J.; Ramírez-Agudelo, O. H.; Taylor, W. D.; Walborn, N. R.; Clark, J. S.; Crowther, P. A.; Herrero, A.; Gieles, M.; Langer, N.; Lennon, D. J.; Vink, J. S.

    2013-02-01

    Context. The Tarantula Nebula in the Large Magellanic Cloud is our closest view of a starburst region and is the ideal environment to investigate important questions regarding the formation, evolution and final fate of the most massive stars. Aims: We analyze the multiplicity properties of the massive O-type star population observed through multi-epoch spectroscopy in the framework of the VLT-FLAMES Tarantula Survey. With 360 O-type stars, this is the largest homogeneous sample of massive stars analyzed to date. Methods: We use multi-epoch spectroscopy and variability analysis to identify spectroscopic binaries. We also use a Monte-Carlo method to correct for observational biases. By modeling simultaneously the observed binary fraction, the distributions of the amplitudes of the radial velocity variations and the distribution of the time scales of these variations, we constrain the intrinsic current binary fraction and period and mass-ratio distributions. Results: We observe a spectroscopic binary fraction of 0.35 ± 0.03, which corresponds to the fraction of objects displaying statistically significant radial velocity variations with an amplitude of at least 20 km s-1. We compute the intrinsic binary fraction to be 0.51 ± 0.04. We adopt power-laws to describe the intrinsic period and mass-ratio distributions: f(log 10P/d) ~ (log 10P/d)π (with log 10P/d in the range 0.15-3.5) and f(q) ~ qκ with 0.1 ≤ q = M2/M1 ≤ 1.0. The power-law indexes that best reproduce the observed quantities are π = -0.45 ± 0.30 and κ = -1.0 ± 0.4. The period distribution that we obtain thus favours shorter period systems compared to an Öpik law (π = 0). The mass ratio distribution is slightly skewed towards low mass ratio systems but remains incompatible with a random sampling of a classical mass function (κ = -2.35). The binary fraction seems mostly uniform across the field of view and independent of the spectral types and luminosity classes. The binary fraction in the outer

  8. The VLT-FLAMES Tarantula Survey. XII. Rotational velocities of the single O-type stars

    Science.gov (United States)

    Ramírez-Agudelo, O. H.; Simón-Díaz, S.; Sana, H.; de Koter, A.; Sabín-Sanjulían, C.; de Mink, S. E.; Dufton, P. L.; Gräfener, G.; Evans, C. J.; Herrero, A.; Langer, N.; Lennon, D. J.; Maíz Apellániz, J.; Markova, N.; Najarro, F.; Puls, J.; Taylor, W. D.; Vink, J. S.

    2013-12-01

    Context. The 30 Doradus (30 Dor) region of the Large Magellanic Cloud, also known as the Tarantula nebula, is the nearest starburst region. It contains the richest population of massive stars in the Local Group, and it is thus the best possible laboratory to investigate open questions on the formation and evolution of massive stars. Aims: Using ground-based multi-object optical spectroscopy obtained in the framework of the VLT-FLAMES Tarantula Survey (VFTS), we aim to establish the (projected) rotational velocity distribution for a sample of 216 presumably single O-type stars in 30 Dor. The sample is large enough to obtain statistically significant information and to search for variations among subpopulations - in terms of spectral type, luminosity class, and spatial location - in the field of view. Methods: We measured projected rotational velocities, νesini, by means of a Fourier transform method and a profile fitting method applied to a set of isolated spectral lines. We also used an iterative deconvolution procedure to infer the probability density, P(νe), of the equatorial rotational velocity, νe. Results: The distribution of νesini shows a two-component structure: a peak around 80 kms-1 and a high-velocity tail extending up to ~600 kms-1. This structure is also present in the inferred distribution P(νe) with around 80% of the sample having 0 low-velocity peak is consistent with what has been found in other studies for late O- and early B-type stars. Conclusions: Most of the stars in our sample rotate with a rate less than 20% of their break-up velocity. For the bulk of the sample, mass loss in a stellar wind and/or envelope expansion is not efficient enough to significantly spin down these stars within the first few Myr of evolution. If massive-star formation results in stars rotating at birth with a large portion of their break-up velocities, an alternative braking mechanism, possibly magnetic fields, is thus required to explain the present

  9. Status of the Cherenkov Telescope Array's Large Size Telescopes

    CERN Document Server

    Cortina, J

    2015-01-01

    The Cherenkov Telescope Array (CTA) observatory, will be deployed over two sites in the two hemispheres. Both sites will be equipped with four Large Size Telescopes (LSTs), which are crucial to achieve the science goals of CTA in the 20-200 GeV energy range. Each LST is equipped with a primary tessellated mirror dish of 23 m diameter, supported by a structure made mainly of carbon fibre reinforced plastic tubes and aluminum joints. This solution guarantees light weight (around 100 tons), essential for fast repositioning to any position in the sky in <20 seconds. The camera is composed of 1855 PMTs and embeds the control, readout and trigger electronics. The detailed design is now complete and production of the first LST, which will serve as a prototype for the remaining seven, is well underway. In 2016 the first LST will be installed at the Roque de los Muchachos Observatory on the Canary island of La Palma (Spain). In this talk we will outline the technical solutions adopted to fulfill the design requirem...

  10. Scientific Potential of Einstein Telescope

    CERN Document Server

    Sathyaprakash, B; Acernese, F; Andersson, P Amaro-Seoane N; Arun, K; Barone, F; Barr, B; Barsuglia, M; Beveridge, M Beker N; Birindelli, S; Bose, S; Bosi, L; Braccini, S; Bradaschia, C; Bulik, T; Calloni, E; Cella, G; Mottin, E Chassande; Chelkowski, S; Chincarini, A; Clark, J; Coccia, E; Colacino, C; Colas, J; Cumming, A; Cunningham, L; Cuoco, E; Danilishin, S; Danzmann, K; Salvo, R De; Dent, T; Rosa, R De; Fiore, L Di; Virgilio, A Di; Doets, M; Fafone, V; Falferi, P; Flaminio, R; Franc, J; Frasconi, F; Freise, A; Friedrich, D; Fulda, P; Gair, J; Gemme, G; Genin, E; Gennai, A; Giazotto, A; Glampedakis, K; Gräf, C; Granata, M; Grote, H; Guidi, G; Gurkovsky, A; Hammond, G; Hannam, M; Harms, J; Heinert, D; Hendry, M; Heng, I; Hennes, E; Hild, S; Hough, J; Husa, S; Huttner, S; Jones, G; Khalili, F; Kokeyama, K; Kokkotas, K; Krishnan, B; Li, T G F; Lorenzini, M; Lück, H; Majorana, E; Mandel, I; Mandic, V; Mantovani, M; Martin, I; Michel, C; Minenkov, Y; Morgado, N; Mosca, S; Mours, B; Müller--Ebhardt, H; Murray, P; Nawrodt, R; Nelson, J; Oshaughnessy, R; Ott, C D; Palomba, C; Paoli, A; Parguez, G; Pasqualetti, A; Passaquieti, R; Passuello, D; Pinard, L; Plastino, W; Poggiani, R; Popolizio, P; Prato, M; Punturo, M; Puppo, P; Rabeling, D; Racz, I; Rapagnani, P; Read, J; Regimbau, T; Rehbein, H; Reid, S; Rezzolla, L; Ricci, F; Richard, F; Rocchi, A; Rowan, S; Rüdiger, A; Santamaría, L; Sassolas, B; Schnabe, R; Schwarz, C; Seidel, P; Sintes, A; Somiya, K; Speirits, F; Strain, K; Strigin, S; Sutton, P; Tarabrin, S; Thüring, A; Brand, J van den; Veggel, M van; Broeck, C van den; Vecchio, A; Veitch, J; Vetrano, F; Vicere, A; Vyatchanin, S; Willke, B; Woan, G; Yamamoto, K

    2011-01-01

    Einstein gravitational-wave Telescope (ET) is a design study funded by the European Commission to explore the technological challenges of and scientific benefits from building a third generation gravitational wave detector. The three-year study, which concluded earlier this year, has formulated the conceptual design of an observatory that can support the implementation of new technology for the next two to three decades. The goal of this talk is to introduce the audience to the overall aims and objectives of the project and to enumerate ET's potential to influence our understanding of fundamental physics, astrophysics and cosmology.

  11. Detectors for the space telescope

    Science.gov (United States)

    Kelsall, T.

    1978-01-01

    This review of Space Telescope (ST) detectors is divided into two parts. The first part gives short summaries of detector programs carried out during the final planning stage (Phase B) of the ST and discusses such detectors as Photicon, the MAMA detectors, the CODACON, the University of Maryland ICCD, the Goddard Space Flight Center ICCD, and the 70 mm SEC TV sensor. The second part describes the detectors selected for the first ST flight, including the wide field/planetary camera, the faint object and high resolution spectrographs, and the high speed photometer.

  12. Cosmography with the Einstein Telescope

    CERN Document Server

    Sathyaprakash, B S; Broeck, Chris Van Den

    2009-01-01

    Einstein Telescope (ET) is a 3rd generation gravitational-wave (GW) detector that is currently undergoing a design study. ET can detect millions of compact binary mergers up to redshifts 2-8. A small fraction of mergers might be observed in coincidence as gamma-ray bursts, helping to measure both the luminosity distance and red-shift to the source. By fitting these measured values to a cosmological model, it should be possible to accurately infer the dark energy equation-of-state, dark matter and dark energy density parameters. ET could, therefore, herald a new era in cosmology.

  13. The Advanced Compton Telescope Mission

    CERN Document Server

    Boggs, S E; Ryan, J; Aprile, E; Gehrels, N; Kippen, M; Leising, M; Oberlack, U; Wunderer, C; Zych, A; Bloser, P; Harris, M; Hoover, A; Klimenk, A; Kocevski, D; McConnell, M; Milne, P; Novikova, E I; Phlips, B; Polsen, M; Sturner, S; Tournear, D; Weidenspointner, G; Wulf, E; Zoglauer, A; Baring, M; Beacom, J; Bildsten, L; Dermer, C; Hartmann, D; Hernanz, M; Smith, D; Starrfield, S; Boggs, Steven E.; Kurfess, James; Ryan, James; Aprile, Elena; Gehrels, Neil; Kippen, Marc; Leising, Mark; Oberlack, Uwe; Wunderer, Cornelia; Zych, Allen; Bloser, Peter; Harris, Michael; Hoover, Andrew; Klimenk, Alexei; Kocevski, Dan; Connell, Mark Mc; Milne, Peter; Novikova, Elena I.; Phlips, Bernard; Polsen, Mark; Sturner, Steven; Tournear, Derek; Weidenspointner, Georg; Wulf, Eric; Zoglauer, Andreas; Baring, Matthew; Beacom, John; Bildsten, Lars; Dermer, Charles; Hartmann, Dieter; Hernanz, Margarita; Smith, David; Starrfield, Sumner

    2006-01-01

    The Advanced Compton Telescope (ACT), the next major step in gamma-ray astronomy, will probe the fires where chemical elements are formed by enabling high-resolution spectroscopy of nuclear emission from supernova explosions. During the past two years, our collaboration has been undertaking a NASA mission concept study for ACT. This study was designed to (1) transform the key scientific objectives into specific instrument requirements, (2) to identify the most promising technologies to meet those requirements, and (3) to design a viable mission concept for this instrument. We present the results of this study, including scientific goals and expected performance, mission design, and technology recommendations.

  14. Serial and subjective clustering on a verbal learning test (VLT) in children aged 5-15: the nature of subjective clustering.

    Science.gov (United States)

    Meijs, Celeste; Hurks, Petra; Rozendaal, Nico; Jolles, Jelle

    2013-01-01

    This study investigated which strategies children aged 5-15 years (N = 408) employ while performing a multitrial free recall test of semantically unrelated words. Serial clustering (i.e., a relatively passive strategy) is an index of the sequential consistency of recall order. Subjective clustering (i.e., a more active strategy) is based on similar word groupings in successive trials. Previously, Meijs et al. (2009) found that the level of (serial and subjective) clustering increases with age. At all ages, the level of serial clustering correlates positively with the ability to recall information on VLT trials. However, subjective clustering is more predictive of VLT performance than serial clustering after ≥ 3 trials, but only in children aged 8+. Knowledge on how children organize words (based on, for example, sound or meaning) and how this relates to developmental stage is still lacking. This study revealed that the level of subjective clustering is primarily determined by the position of words in a VLT list. More specifically, primacy (i.e., recall of words 1-3 of the VLT list - whether recalled in the same order or reversed) and recency (i.e., recall of words 14-15) effects primarily determine level subjective organization over successive trials. Thus, older children still organize words based on the serial position of the VLT list and are much less likely to organize them based on any other feature of the words, for example, sound or meaning. This indicates that the most important information to be learned needs to be presented first or last, even in older children and even with repeated presentations.

  15. The Large Area Telescope on the Fermi Gamma-ray Space Telescope Mission

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, W.B.; /UC, Santa Cruz; Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Anderson, B. /UC, Santa Cruz; Axelsson, M.; /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Band, D.L.; /NASA, Goddard /NASA, Goddard; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bartelt, J.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bastieri, Denis; /INFN, Padua /Padua U.; Baughman, B.M.; /Ohio State U.; Bechtol, K.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bederede, D.; /DAPNIA, Saclay; Bellardi, F.; /INFN, Pisa; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Bignami, G.F.; /Pavia U.; Bisello, D.; /INFN, Padua /Padua U.; Bissaldi, E.; /Garching, Max Planck Inst., MPE; Blandford, R.D.; /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Perugia /Perugia U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /INFN, Pisa /INFN, Pisa /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /INFN, Padua /Padua U. /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /IASF, Milan /IASF, Milan /Kalmar U. /Royal Inst. Tech., Stockholm /DAPNIA, Saclay /ASI, Rome /INFN, Pisa /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /DAPNIA, Saclay /NASA, Goddard /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept. /Montpellier U. /Stanford U., HEPL /KIPAC, Menlo Park /Stanford U., Phys. Dept.; /more authors..

    2009-05-15

    The Large Area Telescope (Fermi/LAT, hereafter LAT), the primary instrument on the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view (FoV), high-energy {gamma}-ray telescope, covering the energy range from below 20 MeV to more than 300 GeV. The LAT was built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. This paper describes the LAT, its preflight expected performance, and summarizes the key science objectives that will be addressed. On-orbit performance will be presented in detail in a subsequent paper. The LAT is a pair-conversion telescope with a precision tracker and calorimeter, each consisting of a 4 x 4 array of 16 modules, a segmented anticoincidence detector that covers the tracker array, and a programmable trigger and data acquisition system. Each tracker module has a vertical stack of 18 (x, y) tracking planes, including two layers (x and y) of single-sided silicon strip detectors and high-Z converter material (tungsten) per tray. Every calorimeter module has 96 CsI(Tl) crystals, arranged in an eight-layer hodoscopic configuration with a total depth of 8.6 radiation lengths, giving both longitudinal and transverse information about the energy deposition pattern. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large FoV (2.4 sr) and ensuring that most pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. Data obtained with the LAT are intended to (1) permit rapid notification of high-energy {gamma}-ray bursts and transients and facilitate monitoring of variable sources, (2) yield an extensive catalog of several thousand high-energy sources obtained from an all-sky survey, (3

  16. The VIMOS VLT Deep Survey: Tracing the galaxy stellar mass assembly history over the last 8Gyr

    CERN Document Server

    Vergani, D; Pozzetti, L; Iovino, A; Franzetti, P; Garilli, B; Zamorani, G; MacCagni, D; Lamareille, F; Le Fèvre, O; Charlot, S; Contini, T; Bottini, D; Le Brun, V; Picat, J P; Scaramella, R; Tresse, L; Vettolani, G; Zanichelli, A; Adami, C; Arnouts, S; Bardelli, S; Bolzonella, M; Cappi, A; Ciliegi, P; Foucaud, S; Gavignaud, I; Guzzo, L; Ilbert, O; McCracken, H J; Marano, B; Marinoni, C; Mazure, A; Meneux, B; Merighi, R; Paltani, S; Pellò, R; Pollo, A; Radovich, M; Zucca, E; Bondi, M; Bongiorno, A; Brinchmann, J; Cucciati, O; De la Torre, S; Gregorini, L; Mellier, Y; Merluzzi, P; Temporin, S; Walcher, C J

    2007-01-01

    We select a mass limited sample of 4048 objects from the VIMOS VLT Deep Survey (VVDS) in the redshift interval 0.51.3) that continues efficiently down to the local Universe. The underlying stellar ages of LT galaxies apparently do not show evolution, most likely as a result of a continuous and efficient formation of new stars. The activity and efficiency of forming stars are mechanisms depending on galaxy stellar mass, resulting in a largely inefficient stellar mass assembly in massive systems up to z=1.3. The concepts of downsizing in star formation and in mass (or archaeological downsizing) describe a single s cenario which has a top-down evolutionary pattern in star formation as well as in mass assembly. The role of (dry) merging events seems to be only marginal at z<1.3, as our estimated efficiency in stellar mass assembly can account for the progressive accumulation of observed passively evolving galaxies.

  17. The VLT-FLAMES Tarantula Survey VI: Evidence for rotation of the young massive cluster R136

    CERN Document Server

    Hénault-Brunet, V; Evans, C J; Sana, H; Bastian, N; Apellániz, J Maíz; Taylor, W D; Markova, N; Bressert, E; de Koter, A; van Loon, J Th

    2012-01-01

    Although it has important ramifications for both the formation of star clusters and their subsequent dynamical evolution, rotation remains a largely unexplored characteristic of young star clusters (few Myr). Using multi-epoch spectroscopic data of the inner regions of 30 Doradus in the Large Magellanic Cloud (LMC) obtained as part of the VLT-FLAMES Tarantula Survey, we search for rotation of the young massive cluster R136. From the radial velocities of 36 apparently single O-type stars within a projected radius of 10 pc from the centre of the cluster, we find evidence, at the 95% confidence level, for rotation of the cluster as a whole. We use a maximum likelihood method to fit simple rotation curves to our data and find a typical rotational velocity of ~3 km/s. When compared to the low velocity dispersion of R136, our result suggests that star clusters may form with at least ~20% of the kinetic energy in rotation.

  18. The VLT-FLAMES Tarantula Survey. XV. VFTS\\,822: a candidate Herbig B[e] star at low metallicity

    CERN Document Server

    Kalari, V M; Dufton, P L; Evans, C J; Dunstall, P R; Sana, H; Clark, J S; Ellerbroek, L; de Koter, A; Lennon, D J; Taylor, W D

    2014-01-01

    We report the discovery of the B[e] star VFTS 822 in the 30 Doradus star-forming region of the Large Magellanic Cloud, classified by optical spectroscopy from the VLT-FLAMES Tarantula Survey and complementary infrared photometry. VFTS 822 is a relatively low-luminosity (log $L$ = 4.04 $\\pm$ 0.25 $L_{\\odot}$) B8[e] star. In this Letter, we evaluate the evolutionary status of VFTS 822 and discuss its candidacy as a Herbig B[e] star. If the object is indeed in the pre-main sequence phase, it would present an exciting opportunity to measure mass accretion rates at low metallicity spectroscopically, to understand the effect of metallicity on accretion rates.

  19. The Atacama Cosmology Telescope: ACT-CL J0102-4215 "El Gordo," a Massive Merging Cluster at Redshift 0.87

    CERN Document Server

    Menanteau, Felipe; Sifon, Cristobal; Hilton, Matt; Gonzalez, Jorge; Infante, Leopoldo; Barrientos, L Felipe; Baker, Andrew J; Das, Sudeep; Devlin, Mark J; Dunkley, Joanna; Hincks, Adam D; Kosowsky, Arthur; Mardsen, Danica; Marriage, Tobias A; Moodley, Kavilan; Niemack, Michael D; Page, Lyman A; Reese, Erik D; Sehgal, Neelima; Sievers, Jon; Spergel, David N; Staggs, Suzanne T; Wollack, Edward

    2011-01-01

    We present a detailed analysis from new multi-wavelength observations of the exceptional galaxy cluster ACT-CL J0102-4915, likely the most massive, hottest, most X-ray luminous and brightest Sunyaev-Zel'dovich(SZ) effect cluster known at redshifts greater than 0.6. The Atacama Cosmology Telescope collaboration discovered it as the most significant SZ decrement in a sky survey area of 755 square degrees. Our VLT/FORS2 spectra of 89 member galaxies yield a cluster redshift, z=0.870, and velocity dispersion, sigma=1321+/-106 km/s. Our Chandra observations reveal a hot and X-ray luminous system with an integrated temperature of Tx=14.5+/-0.1 keV and 0.5-2.0 keV band luminosity of Lx=(2.19+/-0.11) x 10^45 h_70^-2 erg/s. We obtain several statistically consistent cluster mass estimates; using empirical mass scaling relations with velocity dispersion, X-ray Yx, and integrated SZ distortion, we estimate a cluster mass of M_200=(2.16+/-0.32)x10^15 M_sun/h_70. The Chandra and VLT/FORS2 optical data also reveal that ACT...

  20. Corrector systems for cassegrain telescopes.

    Science.gov (United States)

    Wilson, R N

    1968-02-01

    Most modern reflecting telescopes have relative apertures of about f/3 and f/8 for the primary and first secondary foci in accordance with the suggestions of Bowen. The angular field which can be used at the first secondary focus is limited by the size of available plates for large instruments but can approach +/-1 degrees for smaller systems. The factors influencing the choice of the field corrector system in the first secondary focus are discussed. It is an important point whether the Ritchey-Chrétien form of the mirrors is strictly maintained-giving an optimum field without the corrector-or whether the aspheric constants are allowed to vary as free parameters. The differences are small but significant. The performance of a number of secondary focus correctors consisting of one, two, and three elements is discussed, spot diagrams being given in each case. Systems with fixed Ritchey-Chrétien mirror constants are inferior to those with free mirror constants. Test methods for the manufacture of the mirrors of telescopes of this type are compared. A doublet type corrector is suitable for compensation testing of primary mirrors or for secondaries tested from the back, but the testing of the latter from the front is more difficult. Several possible techniques are discussed.

  1. Origins Space Telescope: Community Participation

    Science.gov (United States)

    Carey, Sean J.; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its imagers and spectrographs will enable a variety of surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. This poster will outline the ways in which the astronomical community can participate in the STDT activities and a summary of tools that are currently available or are planned for the community during the study. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu.

  2. Far Ultraviolot Space Telescope (FAUST)

    Science.gov (United States)

    Bowyer, S.

    1988-01-01

    The Far Ultraviolet Space Telescope is a compact, wide field-of-view, far ultraviolet instrument designed for observations of extended and point sources of astronomical interest. It was originally used in sounding rocket work by both French and American investigators. The instrument was modified for flight on the space shuttle and flew on the Spacelab 1 mission as a joint effort between the Laboratoire d'Astronomie Spatiale and the University of California, Berkeley. The prime experiment objective of this telescope on the Atmospheric Laboratory Applications and Science (ATLAS 1) NASA mission is to observe faint astronomical sources in the far ultraviolet with sensitivities far higher than previously available. The experiment will cover the 1300 to 1800 A band, which is inaccessible to observers on earth. The observing program during the mission consists of obtaining deep sky images during spacecraft nighttime. The targets will include hot stars and nebulae in our own galaxy, faint diffuse galactic features similar to the cirrus clouds seen by the Infrared Astronomical Satellite (IRAS), large nearby galaxies, nearby clusters of galaxies, and objects of cosmological interest such as quasars and the diffuse far ultraviolet background.

  3. Origins Space Telescope: Study Plan

    Science.gov (United States)

    Cooray, Asantha R.; Origins Space Telescope Study Team

    2017-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. This presentation will provide a summary of the OST STDT, the OST Study Team based at NASA Goddard Space Flight Center, study partners, and the advisory panel to the study. This presentation will also summarize recent activities, including the process used to reach a decision on the mission architecture, the identification of key science drivers, and the key study milestones between 2017 and 2020.

  4. ANTARES: An Undersea Neutrino telescope

    CERN Multimedia

    2002-01-01

    The ANTARES (Astronomy with a Neutrino Telescope and ${Abyss}$ environmental RESearch) deep-sea neutrino telescope is designed to search for neutrinos of astrophysical origin. Neutrinos are unique probes of the high energy universe; being neutral they are not deflected by magnetic fields and interacting weakly they can readily escape from the densest regions of the universe. Potential sources of neutrino are galactic (e.g supernova remnants, micro-quasars) and extra-galactic (e.g active galactic nuclei, gamma-ray bursters). Annihilation of dark matter particles in the Sun or Galactic Centre is another well motivated potential source of extra terrestrial neutrinos. The ANTARES detector is located 40 km off the coast of Toulon (France) at a depth of 2475m in the Mediterranean Sea. Being located in the Northern hemisphere it studies the Southern sky and in particular has the Galactic Centre in its field of view. Since 2006, the detector has operated continuously in a partial configuration. The detector was compl...

  5. Merz telescopes a global heritage worth preserving

    CERN Document Server

    2017-01-01

    This book comprises a fascinating collection of contributions on the Merz telescopes in Italy that collectively offer the first survey on historical large refracting telescopes in the country, drawing on original documents and photographs. It opens with a general introduction on the importance of Merz telescopes in the history of astronomy and analyses of the local and international contexts in which the telescopes were made. After examination of an example of the interaction between the maker and the astronomer in the construction and maintenance of these refractors, the history of the Merz telescopes at the main Italian observatories in the nineteenth century is described in detail. Expert testimony is also provided on how these telescopes were successfully used until the second half of the twentieth century for research purposes, thus proving their excellent optical qualities.

  6. Launch Will Create a Radio Telescope Larger than Earth

    Science.gov (United States)

    . This includes the National Science Foundation's Very Long Baseline Array (VLBA), an array of 10 telescopes spanning the United States from Hawaii to Saint Croix; NASA's Deep Space Network (DSN) sites in California, Spain, and Australia; the European VLBI Network, more than a dozen telescopes ranging from the United Kingdom to China; a Southern Hemisphere array of telescopes stretching from eastern Australia to South Africa; and Japan's network of domestic radio telescopes. In the United States, NASA is funding critical roles in the VSOP mission at both JPL and NRAO. JPL has built an array of three new tracking stations at its DSN sites in Goldstone, CA; Madrid, Spain; and near Canberra, Australia. A large existing tracking station at each of these sites has also been converted to an extremely sensitive radio telescope for simultaneous observations with the satellite. JPL also is providing precision orbit determination, scientific and operational planning support to the Japanese, and advice to U.S. astronomers who wish to observe with the satellite. NRAO is building a new tracking station at Green Bank, WV; contributing observing time on the VLBA array of telescopes; modifying existing data analysis hardware and software, and aiding astronomers with the analysis of the VSOP data. Much of the observational data will be processed at NRAO's facility in Socorro, NM, using the VLBA Correlator, a special purpose high-performance computer designed to process VLBI data. VSOP is the culmination of many years of planning and work by scientists and engineers around the world. Tests using NASA's Tracking and Data Relay Satellite System (TDRSS) proved the feasibility of space VLBI in 1986. Just last year, those old data were used again to test successfully the data-reduction facilities for VSOP. JPL manages the U.S. Space Very Long Baseline Interferometry project for NASA's Office of Space Science, Washington, DC. The VLBA, headquartered in Socorro, NM, is part of the National Radio

  7. ANTARES: The first undersea neutrino telescope

    Science.gov (United States)

    Ageron, M.; Aguilar, J. A.; Al Samarai, I.; Albert, A.; Ameli, F.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Arnaud, K.; Aslanides, E.; Assis Jesus, A. C.; Astraatmadja, T.; Aubert, J.-J.; Auer, R.; Barbarito, E.; Baret, B.; Basa, S.; Bazzotti, M.; Becherini, Y.; Beltramelli, J.; Bersani, A.; Bertin, V.; Beurthey, S.; Biagi, S.; Bigongiari, C.; Billault, M.; Blaes, R.; Bogazzi, C.; de Botton, N.; Bou-Cabo, M.; Boudahef, B.; Bouwhuis, M. C.; Brown, A. M.; Brunner, J.; Busto, J.; Caillat, L.; Calzas, A.; Camarena, F.; Capone, A.; Caponetto, L.; Cârloganu, C.; Carminati, G.; Carmona, E.; Carr, J.; Carton, P. H.; Cassano, B.; Castorina, E.; Cecchini, S.; Ceres, A.; Chaleil, Th.; Charvis, Ph.; Chauchot, P.; Chiarusi, T.; Circella, M.; Compère, C.; Coniglione, R.; Coppolani, X.; Cosquer, A.; Costantini, H.; Cottini, N.; Coyle, P.; Cuneo, S.; Curtil, C.; D'Amato, C.; Damy, G.; van Dantzig, R.; de Bonis, G.; Decock, G.; Decowski, M. P.; Dekeyser, I.; Delagnes, E.; Desages-Ardellier, F.; Deschamps, A.; Destelle, J.-J.; di Maria, F.; Dinkespiler, B.; Distefano, C.; Dominique, J.-L.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drogou, J.-F.; Drouhin, D.; Druillole, F.; Durand, D.; Durand, R.; Eberl, T.; Emanuele, U.; Engelen, J. J.; Ernenwein, J.-P.; Escoffier, S.; Falchini, E.; Favard, S.; Fehr, F.; Feinstein, F.; Ferri, M.; Ferry, S.; Fiorello, C.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.-L.; Galatá, S.; Galeotti, S.; Gay, P.; Gensolen, F.; Giacomelli, G.; Gojak, C.; Gómez-González, J. P.; Goret, Ph.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartmann, B.; Heijboer, A. J.; Heine, E.; Hello, Y.; Henry, S.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hogenbirk, J.; Hsu, C. C.; Hubbard, J. R.; Jaquet, M.; Jaspers, M.; de Jong, M.; Jourde, D.; Kadler, M.; Kalantar-Nayestanaki, N.; Kalekin, O.; Kappes, A.; Karg, T.; Karkar, S.; Karolak, M.; Katz, U.; Keller, P.; Kestener, P.; Kok, E.; Kok, H.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kretschmer, W.; Kruijer, A.; Kuch, S.; Kulikovskiy, V.; Lachartre, D.; Lafoux, H.; Lagier, P.; Lahmann, R.; Lahonde-Hamdoun, C.; Lamare, P.; Lambard, G.; Languillat, J.-C.; Larosa, G.; Lavalle, J.; Le Guen, Y.; Le Provost, H.; Levansuu, A.; Lefèvre, D.; Legou, T.; Lelaizant, G.; Lévéque, C.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Lucarelli, F.; Lyashuk, V.; Magnier, P.; Mangano, S.; Marcel, A.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Masullo, R.; Mazéas, F.; Mazure, A.; Meli, A.; Melissas, M.; Migneco, E.; Mongelli, M.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Musumeci, M.; Naumann, C.; Naumann-Godo, M.; Neff, M.; Niess, V.; Nooren, G. J. L.; Oberski, J. E. J.; Olivetto, C.; Palanque-Delabrouille, N.; Palioselitis, D.; Papaleo, R.; Păvălaş, G. E.; Payet, K.; Payre, P.; Peek, H.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Picq, C.; Piret, Y.; Poinsignon, J.; Popa, V.; Pradier, T.; Presani, E.; Prono, G.; Racca, C.; Raia, G.; van Randwijk, J.; Real, D.; Reed, C.; Réthoré, F.; Rewiersma, P.; Riccobene, G.; Richardt, C.; Richter, R.; Ricol, J. S.; Rigaud, V.; Roca, V.; Roensch, K.; Rolin, J.-F.; Rostovtsev, A.; Rottura, A.; Roux, J.; Rujoiu, M.; Ruppi, M.; Russo, G. V.; Salesa, F.; Salomon, K.; Sapienza, P.; Schmitt, F.; Schöck, F.; Schuller, J.-P.; Schüssler, F.; Sciliberto, D.; Shanidze, R.; Shirokov, E.; Simeone, F.; Sottoriva, A.; Spies, A.; Spona, T.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Streeb, K.; Sulak, L.; Taiuti, M.; Tamburini, C.; Tao, C.; Tasca, L.; Terreni, G.; Tezier, D.; Toscano, S.; Urbano, F.; Valdy, P.; Vallage, B.; van Elewyck, V.; Vannoni, G.; Vecchi, M.; Venekamp, G.; Verlaat, B.; Vernin, P.; Virique, E.; de Vries, G.; van Wijk, R.; Wijnker, G.; Wobbe, G.; de Wolf, E.; Yakovenko, Y.; Yepes, H.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zúñiga, J.

    2011-11-01

    The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given.

  8. Parameterized Telescoping Proves Algebraic Independence of Sums

    CERN Document Server

    Schneider, Carsten

    2008-01-01

    Usually creative telescoping is used to derive recurrences for sums. In this article we show that the non-existence of a creative telescoping solution, and more generally, of a parameterized telescoping solution, proves algebraic independence of certain types of sums. Combining this fact with summation-theory shows transcendence of whole classes of sums. Moreover, this result throws new light on the question why, e.g., Zeilberger's algorithm fails to find a recurrence with minimal order.

  9. Resolution studies with the DATURA beam telescope

    CERN Document Server

    Jansen, Hendrik

    2016-01-01

    We present resolution studies carried out with the DATURA beam telescope, which belongs to the family of EUDET-type beam telescopes. The EUDET-type beam telescopes make use of CMOS MIMOSA 26 pixel detectors for particle tracking allowing for precise characterisation of particle sensing devices. A profound understanding of the performance of the beam telescope as a whole is obtained by a detailed characterisation of the sensors themselves. We extract the differential intrinsic resolution as measured in a MIMOSA 26 sensor using an iterative pull method and show various clustersize dependent quantities as the residual distribution, the intra-pixel residual width distribution and the intra-pixel frequency distribution.

  10. MAD about the Large Magellanic Cloud: preparing for the era of Extremely Large Telescopes

    CERN Document Server

    Fiorentino, G; Diolaiti, E; Valenti, E; Cignoni, M; Mackey, A D

    2011-01-01

    We present J, H, Ks photometry from the the Multi conjugate Adaptive optics Demonstrator (MAD), a visitor instrument at the VLT, of a resolved stellar population in a small crowded field in the bar of the Large Magellanic Cloud near the globular cluster NGC 1928. In a total exposure time of 6, 36 and 20 minutes, magnitude limits were achieved of J \\sim 20.5 mag, H \\sim 21 mag, and Ks \\sim20.5 mag respectively, with S/N> 10. This does not reach the level of the oldest Main Sequence Turnoffs, however the resulting Colour-Magnitude Diagrams are the deepest and most accurate obtained so far in the infrared for the LMC bar. We combined our photometry with deep optical photometry from the Hubble Space Telescope/Advanced Camera for Surveys, which is a good match in spatial resolution. The comparison between synthetic and observed CMDs shows that the stellar population of the field we observed is consistent with the star formation history expected for the LMC bar, and that all combinations of IJHKs filters can, with ...

  11. Hubble Space Telescope Observations of cD Galaxies and their Globular Cluster Systems

    CERN Document Server

    Jordan, A; West, M J; Marzke, R O; Minniti, D; Rejkuba, M; Jordan, Andres; Cote, Patrick; West, Michael J.; Marzke, Ronald O.; Minniti, Dante; Rejkuba, Marina

    2004-01-01

    We have used WFPC2 on the Hubble Space Telescope to obtain F450W and F814W images of four cD galaxies (NGC 541 in Abell 194, NGC 2832 in Abell 779, NGC 4839 in Abell 1656 and NGC 7768 in Abell 2666) in the range 5400 < cz < 8100 km s^{-1}. For NGC 541, the HST data are supplemented by ground-based B and I images obtained with the FORS1 on the VLT. We present surface brightness and color profiles for each of the four galaxies, confirming their classification as cD galaxies. Isophotal analyses reveal the presence of subarcsecond-scale dust disks in the nuclei of NGC 541 and NGC 7768. Despite the extreme nature of these galaxies in terms of spatial extent and luminosity, our analysis of their globular cluster systems reveals no anomalies in terms of specific frequencies, metallicity gradients, average metallicities, or the metallicity offset between the globulars and the host galaxy. We show that the latter offset appears roughly constant at \\Delta [Fe/H] ~ 0.8 dex for early-type galaxies spanning a lumino...

  12. Prospects for Characterizing Host Stars of the Planetary System Detections Predicted for the Korean Microlensing Telescope Network

    CERN Document Server

    Henderson, Calen B

    2014-01-01

    I investigate the possibility of constraining the flux of the lens (i.e., host star) for the types of planetary systems the Korean Microlensing Telescope Network is predicted to find. I examine the potential to obtain lens flux measurements by 1) imaging a lens once it is spatially resolved from the source, 2) measuring the elongation of the point spread function of the microlensing target (lens+source) when the lens and source are still unresolved, and 3) taking prompt follow-up photometry. In each case I simulate observing programs for a representative example of current ground-based adaptive optics (AO) facilities (specifically NACO on VLT), future ground-based AO facilities (GMTIFS on GMT), and future space telescopes (NIRCAM on $JWST$). Given the predicted distribution of relative lens-source proper motions, I find that the lens flux could be measured to a precision of $\\sigma_{H_{\\ell}} \\leq 0.1$ for $\\gtrsim$60$\\%$ of planet detections $\\geq$5 years after each microlensing event, for a simulated observ...

  13. COSMOS Hubble Space Telescope Observations

    CERN Document Server

    Scoville, N Z; Blain, A W; Calzetti, D; Comastri, A; Capak, P; Carilli, C; Carlstrom, J E; Carollo, C M; Colbert, J; Daddi, E; Ellis, Richard S; Elvis, M; Ewald, S P; Fall, M; Franceschini, A; Giavalisco, M; Green, W; Griffiths, R E; Guzzo, L; Hasinger, G; Impey, C; Kneib, J P; Koda, J; Koekemoer, A; Lefèvre, O; Lilly, S; Liu, C T; McCracken, H J; Massey, R; Mellier, Y; Miyazaki, S; Mobasher, B; Mould, J; Norman, C; Réfrégier, A; Renzini, A; Rhodes, J; Rich, M; Sanders, D B; Schiminovich, D; Schinnerer, E; Scodeggio, M; Sheth, K; Shopbell, P L; Taniguchi, Y; Tyson, N; Urry, C M; Van Waerbeke, L; Vettolani, P; White, S D M; Yan, L

    2006-01-01

    The Cosmic Evolution Survey (COSMOS) was initiated with an extensive allocation (590 orbits in Cycles 12-13) using the Hubble Space Telescope (HST) for high resolution imaging. Here we review the characteristics of the HST imaging with the Advanced Camera for Surveys (ACS) and parallel observations with NICMOS and WFPC2. A square field (1.8$\\sq$\\deg) has been imaged with single-orbit ACS I-F814W exposures with 50% completeness for sources 0.5\\arcsec in diameter at I$_{AB} $ = 26.0 mag. The ACS imaging is a key part of the COSMOS survey, providing very high sensitivity and high resolution (0.09\\arcsec FWHM, 0.05\\arcsec pixels) imaging and detecting a million objects. These images yield resolved morphologies for several hundred thousand galaxies. The small HST PSF also provides greatly enhanced sensitivity for weak lensing investigations of the dark matter distribution.

  14. Adaptive Optics for Large Telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, S

    2008-06-27

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

  15. The ANTARES underwater neutrino telescope

    CERN Document Server

    Montaruli, Teresa

    2015-01-01

    ANTARES is the first undersea neutrino telescope. It is in its complete configuration since May 2008 at about 2.5 km below the sea surface close to Marseille. Data from 12 lines are being analyzed and are producing first results. Here we discuss first analysis results for 5 lines and 10 lines, and we also comment on the performance of the full detector. We show that the detector has capabilities for discriminating upgoing neutrino events from the much larger amount of downgoing atmospheric muons and that data and simulation are in good agreement. We then discuss the physics reach of the detector for what concerns point-like source and dark matter searches.

  16. Can Radio Telescopes Find Axions?

    Science.gov (United States)

    Kohler, Susanna

    2017-08-01

    axions. Now scientists Katharine Kelley and Peter Quinn at ICRAR, University of Western Australia, have explored how we might use next-generation radio telescopes to search for photons that were created by axions interacting with the magnetic fields of our galaxy.Hope for Next-Gen TelescopesPotential axion coupling strengths vs. mass (click for a closer look). The axion mass is thought to lie between a eV and a meV; two theoretical models are shown with dashed lines. The plot shows the sensitivity of the upcoming SKA and its precursors, ASKAP and MEERKAT. [KelleyQuinn 2017]By using a simple galactic halo model and reasonable assumptions for the central galactic magnetic field even taking into account the time dependence of the field Kelley and Quinn estimate the radio-frequency power density that we would observe at Earth from axions being converted to photons within the Milky Ways magnetic field.The authors then compare this signature to the detection capabilities of upcoming radio telescope arrays. They show that the upcoming Square Kilometer Array and its precursors should have the capability to detect signs of axions across large parts of parameter space.Kelley and Quinn conclude that theres good cause for optimism about future radio telescopes ability to detect axions. And if we did succeed in making a detection, it would be a triumph for both particle physics and astrophysics, finally providing an explanation for the universes dark matter.CitationKatharine Kelley and P. J. Quinn 2017 ApJL 845 L4. doi:10.3847/2041-8213/aa808d

  17. Recent Results from Telescope Array

    CERN Document Server

    Fukushima, M

    2015-01-01

    The Telescope Array (TA) is an experiment to observe Ultra-High Energy Cosmic Rays (UHECRs). TA's recent results, the energy spectrum and anisotropy based on the 6-year surface array data, and the primary composition obtained from the shower maximum Xmax are reported. The spectrum demonstrates a clear dip and cutoff. The shape of the spectrum is well described by the energy loss of extra-galactic protons interacting with the cosmic microwave background (CMB). Above the cutoff, a medium-scale (20 degrees radius) flux enhancement was observed near the Ursa-Major. A chance probability of creating this hotspot from the isotropic flux is 4.0 sigma. The measured Xmax is consistent with the primary being proton or light nuclei for energies 10^18.2 eV - 10^19.2 eV.

  18. Cosmography with the Einstein Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Sathyaprakash, B S [School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA (United Kingdom); Schutz, B F [Max Planck Institute for Gravitational Physics, The Albert Einstein Institute, Am Muehlenberg 1, Golm, D-14476 (Germany); Van Den Broeck, C, E-mail: B.Sathyaprakash@astro.cf.ac.u, E-mail: B.F.Schutz@aei.mpg.d, E-mail: vdbroeck@nikhef.n [Nikhef - National Institute for Subatomic Physics, Science Park 105, 1098 XG Amsterdam (Netherlands)

    2010-11-07

    The Einstein Telescope, a third-generation gravitational-wave detector under a design study, could detect millions of binary neutron star inspirals each year. A small fraction of these events might be observed as gamma-ray bursts, helping to measure both the luminosity distance D{sub L} to and redshift z of the source. By fitting these measured values of D{sub L} and z to a cosmological model, it would be possible to infer the dark energy equation of state to within 1.5% without the need to correct for errors in D{sub L} caused by weak lensing. This compares favourably with 0.3-10% accuracy that can be achieved with the Laser Interferometer Space Antenna (where weak lensing will need to be dealt with) as well as with dedicated dark energy missions that have been proposed, where 3.5-11% uncertainty is expected.

  19. NESTOR Deep Sea Neutrino Telescope

    Science.gov (United States)

    NESTOR Collaboration; Aggouras, G.; Anassontzis, E. G.; Ball, A. E.; Bourlis, G.; Chinowsky, W.; Fahrun, E.; Grammatikakis, G.; Green, C.; Grieder, P.; Katrivanos, P.; Koske, P.; Leisos, A.; Markopoulos, E.; Minkowsky, P.; Nygren, D.; Papageorgiou, K.; Przybylski, G.; Resvanis, L. K.; Siotis, I.; Sopher, J.; Staveris-Polikalas, A.; Tsagli, V.; Tsirigotis, A.; Tzamarias, S.; Zhukov, V. A.

    2006-01-01

    One module of NESTOR, the Mediterranean deep-sea neutrino telescope, was deployed at a depth of 4000m, 14km off the Sapienza Island, off the South West coast of Greece. The deployment site provides excellent environmental characteristics. The deployed NESTOR module is constructed as a hexagonal star like latticed titanium star with 12 Optical Modules and an one-meter diameter titanium sphere which houses the electronics. Power and data were transferred through a 30km electro-optical cable to the shore laboratory. In this report we describe briefly the detector and the detector electronics and discuss the first physics data acquired and give the zenith angular distribution of the reconstructed muons.

  20. Diffractive X-Ray Telescopes

    Science.gov (United States)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.