Infrared Testing of the Wide-field Infrared Survey Telescope Grism Using Computer Generated Holograms

Science.gov (United States)

Dominguez, Margaret Z.; Content, David A.; Gong, Qian; Griesmann, Ulf; Hagopian, John G.; Marx, Catherine T; Whipple, Arthur L.

2017-01-01

Infrared Computer Generated Holograms (CGHs) were designed, manufactured and used to measure the performance of the grism (grating prism) prototype which includes testing Diffractive Optical Elements (DOE). The grism in the Wide Field Infrared Survey Telescope (WFIRST) will allow the surveying of a large section of the sky to find bright galaxies.

Resolving the Milky Way and Nearby Galaxies with WFIRST

Science.gov (United States)

Kalirai, Jasonjot

High-resolution studies of nearby stellar populations have served as a foundation for our quest to understand the nature of galaxies. Today, studies of resolved stellar populations constrain fundamental relations -- such as the initial mass function of stars, the time scales of stellar evolution, the timing of mass loss and amount of energetic feedback, the color-magnitude relation and its dependency on age and metallicity, the stellar-dark matter connection in galaxy halos, and the build up of stellar populations over cosmic time -- that represent key ingredients in our prescription to interpret light from the Universe and to measure the physical state of galaxies. More than in any other area of astrophysics, WFIRST will yield a transformative impact in measuring and characterizing resolved stellar populations in the Milky Way and nearby galaxies. The proximity and level of detail that such populations need to be studied at directly map to all three pillars of WFIRST capabilities - sensitivity from a 2.4 meter space based telescope, resolution from 0.1" pixels, and large 0.3 degree field of view from multiple detectors. Our WFIRST GO Science Investigation Team (F) will develop three WFIRST (notional) GO programs related to resolved stellar populations to fully stress WFIRST's Wide Field Instrument. The programs will include a Survey of the Milky Way, a Survey of Nearby Galaxy Halos, and a Survey of Star-Forming Galaxies. Specific science goals for each program will be validated through a wide range of observational data sets, simulations, and new algorithms. As an output of this study, our team will deliver optimized strategies and tools to maximize stellar population science with WFIRST. This will include: new grids of IR-optimized stellar evolution and synthetic spectroscopic models; pipelines and algorithms for optimal data reduction at the WFIRST sensitivity and pixel scale; wide field simulations of MW environments and galaxy halos; cosmological simulations

Colorful Investigations of Supernovae for WFIRST-AFTA

Science.gov (United States)

Foley, Ryan

Type Ia supernovae (SNe Ia) are extremely good probes of dark energy, and WFIRST-AFTA is particularly well suited to make the best SN distance measurements possible. For conservative assumptions, the WFIRST SN survey is projected to have twice the impact as its other probes. Considering that Euclid will only have a minimal SN survey, but strong programs for other dark energy probes, the WFIRST SN survey is especially unique and important. With an initial simulation of the WFIRST-AFTA survey, we have determined that the largest statistical and systematic uncertainties are related to SN color. SN distances strongly depend on the precise measurement of SN colors since we must make a dust extinction correction that depends on the observed color. The details of how the correction is applied and the possibility that the correction evolves with redshift combine with potential calibration systematics to limit the current effectiveness of the SN component of WFIRST-AFTA. Here, we propose to support two graduate students to (1) investigate how intrinsic color variations will impact WFIRST-AFTA systematic uncertainties, (2) determine improved methods for reducing the systematic uncertainties related to SN color, and (3) simulate survey strategies incorporating our results to obtain the highest dark energy figure of merit (DE-FoM).

Understanding the Sun-Earth Libration Point Orbit Formation Flying Challenges For WFIRST and Starshade

Science.gov (United States)

Webster, Cassandra M.; Folta, David C.

2017-01-01

In order to fly an occulter in formation with a telescope at the Sun-Earth L2 (SEL2) Libration Point, one must have a detailed understanding of the dy-namics that govern the restricted three body system. For initial purposes, a linear approximation is satisfactory, but operations will require a high-fidelity modeling tool along with strategic targeting methods in order to be successful. This paper focuses on the challenging dynamics of the transfer trajectories to achieve the relative positioning of two spacecraft to fly in formation at SEL2, in our case, the Wide-Field Infrared Survey Telescope (WFIRST) and a proposed Starshade. By modeling the formation transfers using a high fidelity tool, an accurate V approximation can be made to as-sist with the development of the subsystem design required for a WFIRST and Starshade formation flight mission.

High Fidelity Modeling of SRP and Its Effect on the Relative Motion of Starshade and WFIRST

Science.gov (United States)

Farres, Ariadna; Webster, Cassandra; Folta, Dave

2018-01-01

In this paper we perform a detailed analysis of how Solar Radiation Pressure (SRP) affects the relative motion of two spacecrafts, the Wide-Field Infrared Survey Telescope (WFIRST) and Starshade, orbiting in the vicinity of the Sun-Earth L2. While WFIRST orbits about its own Libration Point Orbit (LPO), Starshade will fly a specific trajectory to align with WFIRST and observe a Design Reference Mission of pre-determined target stars. In this analysis, we focus on the transfer orbit for Starshade from one observation to the other. We will describe how SRP affects the dynamics of the Starshade relative to WFIRSTand how relevant this effect is in order to get an accurate estimate of the total difference in velocity (delta v).

WFIRST: STScI Science Operations Center (SSOC) Activities and Plans

Science.gov (United States)

Gilbert, Karoline M.; STScI WFIRST Team

2018-01-01

The science operations for the WFIRST Mission will be distributed between Goddard Space Flight Center, the Space Telescope Science Institute (STScI), and the Infrared Processing and Analysis Center (IPAC). The STScI Science Operations Center (SSOC) will schedule and archive all WFIRST observations, will calibrate and produce pipeline-reduced data products for the Wide Field Instrument, and will support the astronomical community in planning WFI observations and analyzing WFI data. During the formulation phase, WFIRST team members at STScI have developed operations concepts for scheduling, data management, and the archive; have performed technical studies investigating the impact of WFIRST design choices on data quality and analysis; and have built simulation tools to aid the community in exploring WFIRST’s capabilities. We will highlight examples of each of these efforts.

WFIRST Project Science Activities

Science.gov (United States)

Gehrels, Neil

2012-01-01

The WFIRST Project is a joint effort between GSFC and JPL. The project scientists and engineers are working with the community Science Definition Team to define the requirements and initial design of the mission. The objective is to design an observatory that meets the WFIRST science goals of the Astr02010 Decadal Survey for minimum cost. This talk will be a report of recent project activities including requirements flowdown, detector array development, science simulations, mission costing and science outreach. Details of the interim mission design relevant to scientific capabilities will be presented.

Comparison of wavefront control algorithms and first results on the high-contrast imager for complex aperture telescopes (hicat) testbed

Science.gov (United States)

Leboulleux, L.; N'Diaye, M.; Mazoyer, J.; Pueyo, L.; Perrin, M.; Egron, S.; Choquet, E.; Sauvage, J.-F.; Fusco, T.; Soummer, R.

2017-09-01

The next generation of space telescopes for direct imaging and spectroscopy of exoplanets includes telescopes with a monolithic mirror, such as the Wide Field Infrared Survey Telescope (WFIRST) [1] and Large Ultra-Violet Optical Infrared (LUVOIR) telescopes with segmented primary mirror, like ATLAST [2, 3] or HDST [4].

Spectral and Wavefront Error Performance of WFIRST-AFTA Bandpass Filter Coating Prototypes

Science.gov (United States)

Quijada, Manuel A.; Seide, Laurie; Pasquale, Bert A.; McMann, Joseph C.; Hagopian, John G.; Dominguez, Margaret Z.; Gong, Quian; Marx, Catherine T.

2016-01-01

The Cycle 5 design baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRST/AFTA) instrument includes a single wide-field channel (WFC) instrument for both imaging and slit-less spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a Grism that will consist of a three-element assembly to disperse the full field with an undeviated central wavelength for galaxy redshift surveys. All filter elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper presents and discusses the performance (including spectral transmission and reflected/transmitted wavefront error measurements) of a subset of bandpass filter coating prototypes that are based on the WFC instrument filter compliment. The bandpass coating prototypes that are tested in this effort correspond to the Z087, W149, and Grism filter elements. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput, out of band rejection (including the cut-on and cutoff slopes), and the impact the wavefront error distortions of these filter coatings will have on the imaging performance of the wide-field channel in the WFIRST/AFTA observatory.

Archival Research Capabilities of the WFIRST Data Set

Science.gov (United States)

Szalay, Alexander

WFIRST's unique combination of a large (~0.3 deg2) field of view and HST-like angular resolution and sensitivity in the near infrared will produce spectacular new insights into the origins of stars, galaxies, and structure in the cosmos. We propose a WFIRST Archive Science Investigation Team (SIT-F) to define an archival, query, and analysis system that will enable scientific discovery in all relevant areas of astrophysics and maximize the overall scientific yield of the mission. Guest investigators (GIs), guest observers (GOs), the WFIRST SIT's, WFIRST Science Center(s), and astronomers using data from other surveys will all benefit from the extensive, easy, fast and reliable use of the WFIRST archives. We propose to develop the science requirements for the archive and work to understand its interactions with other elements of the WFIRST mission. To accomplish this, we will conduct case studies to derive performance requirements for the WFIRST archives. These will clarify what is needed for GIs to make important scientific discoveries across a broad range of astrophysics. While other SITs will primarily address the science capabilities of the WFIRST instruments, we will look ahead to the science enabling capabilities of the WFIRST archives. We will demonstrate how the archive can be optimized to take advantage of the extraordinary science capabilities of the WFIRST instruments as well as major space and ground observatories to maximize the science return of the mission. We will use the "20 queries" methodology, formulated by Jim Gray, to cover the most important science analysis patterns and use these to establish the performance required of the WFIRST archive. The case studies will be centered on studying galaxy evolution as a function of cosmic time, environment and intrinsic properties. The analyses will require massive angular and spatial cross correlations between key galaxy properties to search for new fundamental scaling relations that may only become

Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) for WFIRST-AFTA

Science.gov (United States)

Gong, Qian; Mcelwain, Michael; Greeley, Bradford; Grammer, Bryan; Marx, Catherine; Memarsadeghi, Nargess; Stapelfeldt, Karl; Hilton, George; Sayson, Jorge Llop; Perrin, Marshall;

Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) for WFIRST/AFTA

Science.gov (United States)

Gong, Qian; Mcelwain, Michael; Greeley, Bradford; Grammer, Bryan; Marx, Catherine; Memarsadeghi, Nargess; Stapelfeldt, Karl; Hilton, George; Sayson, Jorge Llop; Perrin, Marshall;

The Science Advantage of a Redder Filter for WFIRST

Science.gov (United States)

Bauer, James; Stauffer, John; Milam, Stefanie N.; Holler, Bryan J.

2018-01-01

WFIRST will be capable of providing Hubble-quality imaging performance over several thousand square degrees of the sky. The wide-area, high spatial resolution survey data from WFIRST will be unsurpassed for probably many decades into the future. With the current baseline design, the WFIRST filter complement will extend from the bluest wavelength allowed by the optical design to a reddest filter (F184W) that has a red cutoff at 2.0 microns. Extension of the imaging capabilities even slightly beyond the 2.0 micron wavelength cut-off would provide significant advantages over the presently proposed science for objects both near and far. The inclusion of a Ks (2.0-2.3 micron) filter would result in a wider range and more comprehensive set of Solar System investigations. It would also extend the range of higher-redshift population studies. In this poster, we outline some of the science advantages for adding a K filter, similar in bandpass to the 2MASS Ks filter, in order to extend the wavelength range for WFIRST as far to the red as the thermal performance of the spacecraft allows.

WFIRST: Microlensing Analysis Data Challenge

Science.gov (United States)

Street, Rachel; WFIRST Microlensing Science Investigation Team

2018-01-01

WFIRST will produce thousands of high cadence, high photometric precision lightcurves of microlensing events, from which a wealth of planetary and stellar systems will be discovered. However, the analysis of such lightcurves has historically been very time consuming and expensive in both labor and computing facilities. This poses a potential bottleneck to deriving the full science potential of the WFIRST mission. To address this problem, the WFIRST Microlensing Science Investigation Team designing a series of data challenges to stimulate research to address outstanding problems of microlensing analysis. These range from the classification and modeling of triple lens events to methods to efficiently yet thoroughly search a high-dimensional parameter space for the best fitting models.

The UV Survey Mission Concept, CETUS

Science.gov (United States)

Heap, Sara; and the CETUS Team

2018-01-01

In March 2017, NASA selected CETUS for study of a Probe-class mission concept. W. Danchi is the CETUS PI, and S. Heap is the Science PI. CETUS is primarily a UV survey telescope to complement survey telescopes of the 2020’s including E-ROSITA, Subaru Hyper Suprime Cam and Prime-Focus Spectrograph, WFIRST, and the Square Kilometer Array. CETUS comprises a 1.5-m wide-field telescope and three science instruments: a wide-field (1045” on a side) far-UV and near-UV camera; a similarly wide-field near-UV multi-object spectrograph utilizing a next-generation micro-shutter array; and a single-object spectrograph with options of spectral region (far-UV or near-UV) and spectral resolving power (2,000 or 40,000). The survey instruments will operate simultaneously thereby producing wide-field images in the near-UV and far-UV and a spectrogram containing near-UV spectra of up to 100 sources free of spectral overlap and astronomical background. ln concert with other survey telescopes, CETUS will focus on understanding galaxy evolution at cosmic noon (z~1-2).

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.

Realistic Simulations of Coronagraphic Observations with WFIRST

Science.gov (United States)

Rizzo, Maxime; Zimmerman, Neil; Roberge, Aki; Lincowski, Andrew; Arney, Giada; Stark, Chris; Jansen, Tiffany; Turnbull, Margaret; WFIRST Science Investigation Team (Turnbull)

2018-01-01

We present a framework to simulate observing scenarios with the WFIRST Coronagraphic Instrument (CGI). The Coronagraph and Rapid Imaging Spectrograph in Python (crispy) is an open-source package that can be used to create CGI data products for analysis and development of post-processing routines. The software convolves time-varying coronagraphic PSFs with realistic astrophysical scenes which contain a planetary architecture, a consistent dust structure, and a background field composed of stars and galaxies. The focal plane can be read out by a WFIRST electron-multiplying CCD model directly, or passed through a WFIRST integral field spectrograph model first. Several elementary post-processing routines are provided as part of the package.

WFIRST: Exoplanet Data Challenge. Atmospheric retrieval results

Science.gov (United States)

Hildebrandt, Sergi; Turnbull, Margaret; Exoplanet Data Challenge Team

2018-01-01

We present the results of the Exoplanet Data Challenge for its first 2016/17 cycle and the current cycle 2. Some input spectra for extra-solar systems are processed through the WFIRST IFS instrument model, producing simulated data representative of the flight data. Atmospheric properties are then recovered using complex atmospheric models and multidimensional optimization. The results inform about WFIRST CGI ability to characterize exo-planetray atmospheres.

Optical Design for a Survey X-Ray Telescope

Science.gov (United States)

Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

2014-01-01

Optical design trades are underway at the Goddard Space Flight Center to define a telescope for an x-ray survey mission. Top-level science objectives of the mission include the study of x-ray transients, surveying and long-term monitoring of compact objects in nearby galaxies, as well as both deep and wide-field x-ray surveys. In this paper we consider Wolter, Wolter-Schwarzschild, and modified Wolter-Schwarzschild telescope designs as basic building blocks for the tightly nested survey telescope. Design principles and dominating aberrations of individual telescopes and nested telescopes are discussed and we compare the off-axis optical performance at 1.0 KeV and 4.0 KeV across a 1.0-degree full field-of-view.

Preparatory studies for the WFIRST supernova cosmology measurements

Science.gov (United States)

Perlmutter, Saul

tune details, like the wavelength coverage and S/N requirements, of the WFIRST IFS to capitalize on these systematic error reduction methods. b) Supernova extraction and host galaxy subtractions. The underlying light of the host galaxy must be subtracted from the supernova images making up the lightcurves. Using the IFS to provide the lightcurve points via spectrophotometry requires the subtraction of a reference spectrum of the galaxy taken after the supernova light has faded to a negligible level. We plan to apply the expertise obtained from the SNfactory to develop galaxy background procedures that minimize the systematic errors introduced by this step in the analysis. c) Instrument calibration and ground to space cross calibration. Calibrating the entire supernova sample will be a challenge as no standard stars exist that span the range of magnitudes and wavelengths relevant to the WFIRST survey. Linking the supernova measurements to the relatively brighter standards will require several links. WFIRST will produce the high redshift sample, but the nearby supernova to anchor the Hubble diagram will have to come from ground based observations. Developing algorithms to carry out the cross calibration of these two samples to the required one percent level will be an important goal of our proposal. An integral part of this calibration will be to remove all instrumental signatures and to develop unbiased measurement techniques starting at the pixel level. We then plan to pull the above studies together in a synthesis to produce a correlated error matrix. We plan to develop a Fisher Matrix based model to evaluate the correlated error matrix due to the various systematic errors discussed above. A realistic error model will allow us to carry out a more reliable estimates of the eventual errors on the measurement of the cosmological parameters, as well as serve as a means of optimizing and fine tuning the requirements for the instruments and survey strategies.

WFIRST: Update on the Coronagraph Science Requirements

Science.gov (United States)

Douglas, Ewan S.; Cahoy, Kerri; Carlton, Ashley; Macintosh, Bruce; Turnbull, Margaret; Kasdin, Jeremy; WFIRST Coronagraph Science Investigation Teams

2018-01-01

The WFIRST Coronagraph instrument (CGI) will enable direct imaging and low resolution spectroscopy of exoplanets in reflected light and imaging polarimetry of circumstellar disks. The CGI science investigation teams were tasked with developing a set of science requirements which advance our knowledge of exoplanet occurrence and atmospheric composition, as well as the composition and morphology of exozodiacal debris disks, cold Kuiper Belt analogs, and protoplanetary systems. We present the initial content, rationales, validation, and verification plans for the WFIRST CGI, informed by detailed and still-evolving instrument and observatory performance models. We also discuss our approach to the requirements development and management process, including the collection and organization of science inputs, open source approach to managing the requirements database, and the range of models used for requirements validation. These tools can be applied to requirements development processes for other astrophysical space missions, and may ease their management and maintenance. These WFIRST CGI science requirements allow the community to learn about and provide insights and feedback on the expected instrument performance and science return.

WFIRST: Coronagraph Systems Engineering and Performance Budgets

Science.gov (United States)

Poberezhskiy, Ilya; cady, eric; Frerking, Margaret A.; Kern, Brian; Nemati, Bijan; Noecker, Martin; Seo, Byoung-Joon; Zhao, Feng; Zhou, Hanying

2018-01-01

The WFIRST coronagraph instrument (CGI) will be the first in-space coronagraph using active wavefront control to directly image and characterize mature exoplanets and zodiacal disks in reflected starlight. For CGI systems engineering, including requirements development, CGI performance is predicted using a hierarchy of performance budgets to estimate various noise components — spatial and temporal flux variations — that obscure exoplanet signals in direct imaging and spectroscopy configurations. These performance budgets are validated through a robust integrated modeling and testbed model validation efforts.We present the performance budgeting framework used by WFIRST for the flow-down of coronagraph science requirements, mission constraints, and observatory interfaces to measurable instrument engineering parameters.

Investigating the Nature of Dark Energy using Type Ia Supernovae with WFIRST-AFTA Space Mission

Science.gov (United States)

Perlmutter, Saul

data challenges to validate the above 6. Development of complete plans in coordination with WFIRST project, for all aspects of science simulations, precursor observations, ground calibration, observational needs, data processing, anciliary data collection/incorporation, analysis, dissemination and documentation of the proposed science investigation. The 5 year program also intends to provide the following deliverables: 1. Documentation describing detailed scientific performance requirements 2. Documentation describing a design of an observing program 3. Documentation of science data analysis techniques 4. Simulations and data challenges to validate the above items 5. Algorithms used to perform processing of science data to serve as a basis for the WFIRST pipeline To achieve these objectives the plan is to set up a Supernova Project Office, seven Supernova Working Groups, and two Supernova Software Deliverables Teams. During the recent years of work with the Science Definition Team, it has been clear that the WFIRST Project Office requires a continuous series of scientific answers to the stream of design and requirements questions that arise in the development of the mission. One of the highest priorities of the Supernova Project Office will be to coordinate with the WFIRST Project Office and be the one-stop-shopping source of answers to such questions. The second topic of this proposal is Weak Lensing (WL). The intrinsic broad wavelength coverage and excellent flux calibration of the IFU spectra will provide an important training for the photometric redshift measurements, beyond what is possible from the ground, required for the WL survey. At this time the IFU design details are not fully developed, and our studies will ensure that the WL photo-z requirements are folded into a realistic final IFU design.

WFIRST CGI Adjutant Scientist

Science.gov (United States)

Kasdin, N.

One of the most exciting developments in exoplanet science is the inclusion of a coronagraph instrument on WFIRST. After more than 20 years of research and development on coronagraphy and wavefront control, the technology is ready for a demonstration in space and to be used for revolutionary science. Good progress has already been made at JPL and partner institutions on the coronagraph technology and instrument design and test. The next five years as we enter Phase A will be critical for raising the TRL of the coronagraph to the needed level for flight and for converging on a design that is robust, low risk, and meets the science requirements. In addition, there is growing excitement over the possibility of rendezvousing an occulter with WFIRST/AFTA as a separate mission; this would both demonstrate that important technology and potentially dramatically enhance the science reach, introducing the possibility of imaging Earth-like planets in the habitable zone of nearby stars. In this proposal I will be applying for the Coronagraph Adjutant Scientist (CAS) position. I bring to the position the background and skills needed to be an effective liaison between the project office, the instrument team, and the Science Investigation Team (SIT). My background in systems engineering before coming to Princeton (I was Chief Systems Engineer for the Gravity Probe-B mission) and my 15 years of working closely with NASA on both coronagraph and occulter technology make me well-suited to the role. I have been a lead coronagraph scientist for the WFIRST mission from the beginning, including as a member of the SDT. Together with JPL and NASA HQ, I helped organize the process for selecting the coronagraphs for the CGI, one of which, the shaped pupil, has been developed in my lab. All of the key algorithms for wavefront control (including EFC and Stroke Minimization) were originally developed by students or post-docs in my lab at Princeton. I am thus in a unique position to work with

Chinese large solar telescopes site survey

Science.gov (United States)

Liu, Yu

2017-04-01

In order to observe the solar surface with unprecedentedly higher resolution, Chinse solar physics society decided to launch their solar site survey project in 2010 as the first step to look for the best candidate sites for the Chinese next-generation large-aperture solar telescopes, i.e., the 5-8 meter Chinese Giant Solar Telescope, and the 1 meter level coronagraph. We have built two long-term monitoring sites in Daocheng, with altitudes of around 4800 meters above the sea level located in the large Shangri-La mountain area, and we have collected systematic site data since 2014. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that the large Shangri-La area owns the potential conditions of excellent seeing level and sufficient amount of clear-sky hours suitable for developing large solar telescopes. We will review the site survey progress and present the preliminary statistical results in this talk.

Enabling Super-Nyquist Wavefront Control on WFIRST

Science.gov (United States)

Bendek, Eduardo; Belikov, Ruslan; Sirbu, Dan; Shaklan, Stuart B.; Eldorado Riggs, A. J.

2018-01-01

A large fraction of sun-like stars is contained in Binary systems. Within 10pc there are 70 FGK stars from which, 43 belong to a multi-star system, and 28 of them have companion leak that is greater than 1e-9 contrast assuming typical Hubble-quality space optics. Currently, those binary stars are not included in the WFIRST-CGI target list, but they could be observed if high-contrast imaging around binary star systems using WFIRST is possible, increasing by 70% the number of possible FGK targets for the mission. The Multi-Star Wavefront Control (MSWC) algorithm can be used to suppress the companion star leakage. If the targets have angular separations larger than the Nyquist controllable region of the Deformable Mirror the MSWC must operate in its Super-Nyquist (SN) mode. This mode requires a target star replica within the SN region in order to provide the energy, and coherent light necessary to null speckles at SN angular separations. For the case of WFIRST, about half of the targets that can be observed using MSWC have angular separations larger than the Nyquist controllable region of the 48x48 actuator Deformable Mirror (DM) to be used. Here, we discuss multiple alternatives to generate those PSF replicas with minimal or no impact to the WFIRST Coronagraph instrument such as 1) the addition of a movable diffractive pupil mounted of the Shape Pupil wheel. 2) Design of a modified Shape Pupil design able to create a dark zone and at the same time diffract a small fraction of the starlight on the SN region. 3) Predict the minimum residual quilting on Xinetics DM that would allow observing a given target.

Wavefront Sensing for WFIRST with a Linear Optical Model

Science.gov (United States)

Jurling, Alden S.; Content, David A.

2012-01-01

In this paper we develop methods to use a linear optical model to capture the field dependence of wavefront aberrations in a nonlinear optimization-based phase retrieval algorithm for image-based wavefront sensing. The linear optical model is generated from a ray trace model of the system and allows the system state to be described in terms of mechanical alignment parameters rather than wavefront coefficients. This approach allows joint optimization over images taken at different field points and does not require separate convergence of phase retrieval at individual field points. Because the algorithm exploits field diversity, multiple defocused images per field point are not required for robustness. Furthermore, because it is possible to simultaneously fit images of many stars over the field, it is not necessary to use a fixed defocus to achieve adequate signal-to-noise ratio despite having images with high dynamic range. This allows high performance wavefront sensing using in-focus science data. We applied this technique in a simulation model based on the Wide Field Infrared Survey Telescope (WFIRST) Intermediate Design Reference Mission (IDRM) imager using a linear optical model with 25 field points. We demonstrate sub-thousandth-wave wavefront sensing accuracy in the presence of noise and moderate undersampling for both monochromatic and polychromatic images using 25 high-SNR target stars. Using these high-quality wavefront sensing results, we are able to generate upsampled point-spread functions (PSFs) and use them to determine PSF ellipticity to high accuracy in order to reduce the systematic impact of aberrations on the accuracy of galactic ellipticity determination for weak-lensing science.

How to find and type red/brown dwarf stars in near-infrared imaging space observatories

Science.gov (United States)

Willemn Holwerda, Benne; Ryan, Russell; Bridge, Joanna; Pirzkal, Nor; Kenworthy, Matthew; Andersen, Morten; Wilkins, Stephen; Trenti, Michele; Meshkat, Tiffany; Bernard, Stephanie; Smit, Renske

2018-01-01

Here we evaluate the near-infrared colors of brown dwarfs as observed with four major infrared imaging space observatories: the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the EUCLID mission, and the WFIRST telescope. We use the splat ISPEX spectroscopic library to map out the colors of the M, L, and T-type brown dwarfs. We identify which color-color combination is optimal for identifying broad type and which single color is optimal to then identify the subtype (e.g., T0-9). We evaluate each observatory separately as well as the the narrow-field (HST and JWST) and wide-field (EULID and WFIRST) combinations.HST filters used thus far for high-redshift searches (e.g. CANDELS and BoRG) are close to optimal within the available filter combinations. A clear improvement over HST is one of two broad/medium filter combinations on JWST: pairing F140M with either F150W or F162M discriminates well between brown dwarf subtypes. The improvement of JWST the filter set over the HST one is so marked that any combination of HST and JWST filters does not improve the classification.The EUCLID filter set alone performs poorly in terms of typing brown dwarfs and WFIRST performs only marginally better, despite a wider selection of filters. A combined EUCLID and WFIRST observation, using WFIRST's W146 and F062 and EUCLID's Y-band, allows for a much better discrimination between broad brown dwarf categories. In this respect, WFIRST acts as a targeted follow-up observatory for the all-sky EUCLID survey. However, subsequent subtyping with the combination of EUCLID and WFIRST observations remains uncertain due to the lack of medium or narrow-band filters in this wavelength range. We argue that a medium band added to the WFIRST filter selection would greatly improve its ability to preselect against brown dwarfs in high-latitude surveys.

The Complete Calibration of the Color–Redshift Relation (C3R2) Survey: Survey Overview and Data Release 1

Energy Technology Data Exchange (ETDEWEB)

Masters, Daniel C. [Infrared Processing and Analysis Center, Pasadena, CA 91125 (United States); Stern, Daniel K.; Rhodes, Jason D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Cohen, Judith G. [California Institute of Technology, Pasadena, CA 91125 (United States); Capak, Peter L. [Spitzer Science Center, Pasadena, CA 91125 (United States); Castander, Francisco J. [Institut de Ciències de lEspai (ICE, IEEC/CSIC), E-08193 Bellaterra (Barcelona) (Spain); Paltani, Stéphane [Department of Astronomy, University of Geneva, Ch. dEcogia 16, 1290 Versoix (Switzerland)

2017-06-01

A key goal of the Stage IV dark energy experiments Euclid , LSST, and WFIRST is to measure the growth of structure with cosmic time from weak lensing analysis over large regions of the sky. Weak lensing cosmology will be challenging: in addition to highly accurate galaxy shape measurements, statistically robust and accurate photometric redshift (photo- z ) estimates for billions of faint galaxies will be needed in order to reconstruct the three-dimensional matter distribution. Here we present an overview of and initial results from the Complete Calibration of the Color–Redshift Relation (C3R2) survey, which is designed specifically to calibrate the empirical galaxy color–redshift relation to the Euclid depth. These redshifts will also be important for the calibrations of LSST and WFIRST . The C3R2 survey is obtaining multiplexed observations with Keck (DEIMOS, LRIS, and MOSFIRE), the Gran Telescopio Canarias (GTC; OSIRIS), and the Very Large Telescope (VLT; FORS2 and KMOS) of a targeted sample of galaxies that are most important for the redshift calibration. We focus spectroscopic efforts on undersampled regions of galaxy color space identified in previous work in order to minimize the number of spectroscopic redshifts needed to map the color–redshift relation to the required accuracy. We present the C3R2 survey strategy and initial results, including the 1283 high-confidence redshifts obtained in the 2016A semester and released as Data Release 1.

The Complete Calibration of the Color–Redshift Relation (C3R2) Survey: Survey Overview and Data Release 1

International Nuclear Information System (INIS)

Masters, Daniel C.; Stern, Daniel K.; Rhodes, Jason D.; Cohen, Judith G.; Capak, Peter L.; Castander, Francisco J.; Paltani, Stéphane

2017-01-01

A key goal of the Stage IV dark energy experiments Euclid , LSST, and WFIRST is to measure the growth of structure with cosmic time from weak lensing analysis over large regions of the sky. Weak lensing cosmology will be challenging: in addition to highly accurate galaxy shape measurements, statistically robust and accurate photometric redshift (photo- z ) estimates for billions of faint galaxies will be needed in order to reconstruct the three-dimensional matter distribution. Here we present an overview of and initial results from the Complete Calibration of the Color–Redshift Relation (C3R2) survey, which is designed specifically to calibrate the empirical galaxy color–redshift relation to the Euclid depth. These redshifts will also be important for the calibrations of LSST and WFIRST . The C3R2 survey is obtaining multiplexed observations with Keck (DEIMOS, LRIS, and MOSFIRE), the Gran Telescopio Canarias (GTC; OSIRIS), and the Very Large Telescope (VLT; FORS2 and KMOS) of a targeted sample of galaxies that are most important for the redshift calibration. We focus spectroscopic efforts on undersampled regions of galaxy color space identified in previous work in order to minimize the number of spectroscopic redshifts needed to map the color–redshift relation to the required accuracy. We present the C3R2 survey strategy and initial results, including the 1283 high-confidence redshifts obtained in the 2016A semester and released as Data Release 1.

C3R2 - Complete Calibration of the Color-Redshift Relation: Keck spectroscopy to train photometric redshifts for Euclid and WFIRST

Science.gov (United States)

Stern, Daniel; C3R2 Team

2017-01-01

A primary objective of both WFIRST and Euclid is to provide a 3D map of the distribution of matter across a significant fraction of the universe from the weak lensing shear field, but to do so requires robust distances to billions of galaxies. I will report on a multi-semester program, expected to total approximately 40 nights with Keck over the next two years. This program, supporting both the NASA PCOS and COR science goals, will obtain the necessary galaxy spectroscopy to calibrate the color-redshift relation for the Euclid mission, and make significant progress towards the WFIRST requirements. The program, called C3R2 or Complete Calibration of the Color-Redshift Relation, already encompasses 10 allocated nights of NASA Keck Key Strategic Mission Support (PI D. Stern), 12 allocated nights from Caltech (PI J. Cohen), 3 allocated nights from the University of Hawaii (PI D. Sanders), and 1.5 allocated nights from UC-Riverside (PI B. Mobasher). We are also pursuing opportunities at additional 8- to 10-meter class telescopes, including Magellan, VLT and GCT. I will present the motivation for this program, the plans, and current results.

Simulation of Telescope Detectivity for Geo Survey and Tracking

Science.gov (United States)

Richard, P.

2014-09-01

As the number of space debris on Earths Orbit increases steadily, the need to survey, track and catalogue them becomes of key importance. In this context, CNES has been using the TAROT Telescopes (Rapid Telescopes for Transient Objects owned and operated by CNRS) for several years to conduct studies about space surveillance and tracking. Today, two testbeds of services using the TAROT telescopes are running every night: one for GEO situational awareness and the second for debris tracking. Additionally to the CNES research activity on space surveillance and tracking domain, an operational collision avoidance service for LEO and GEO satellites is in place at CNES for several years. This service named CAESAR (Conjunction Analysis and Evaluation: Alerts and Recommendations) is used by CNES as well as by external customers. As the optical debris tracking testbed based on TAROT telescopes is the first step toward an operational provider of GEO measures that could be used by CAESAR, simulations have been done to help choosing the sites and types of telescopes that could be added in the GEO survey and debris tracking telescope network. One of the distinctive characteristics of the optical observation of space debris compared to traditional astronomic observation is the need to observe objects at low elevations. The two mains reasons for this are the need to observe the GEO belt from non-equatorial sites and the need to observe debris at longitudes far from the telescope longitude. This paper presents the results of simulations of the detectivity for GEO debris of various telescopes and sites, based on models of the GEO belt, the atmosphere and the instruments. One of the conclusions is that clever detection of faint streaks and spread sources by image processing is one of the major keys to improve the detection of debris on the GEO belt.

M Dwarf Exoplanet Survey by the Falcon Telescope Network

Science.gov (United States)

Carlson, Randall E.

2016-10-01

The Falcon Telescope Network (FTN) consists of twelve automated 20-inch telescopes located around the globe. We control it at the US Air Force Academy in Colorado Springs, Colorado from the Cadet Space Operations Center. We have installed 10 of the 12 sites and anticipate full operational capability by the beginning of 2017. The network's worldwide geographic distribution provides advantages. The primary mission of the FTN is Space Situational Awareness and studying Near Earth Objects. However, we are employing the FTN with its 11' x 11' field-of-view for a five-year, M dwarf exoplanet survey. Specifically, we are searching for Earth-radius exoplanets. We describe the FTN, design considerations going into the FTN's M dwarf exoplanet survey including automated operations, and initial results of the survey.

Effect of DM Actuator Errors on the WFIRST/AFTA Coronagraph Contrast Performance

Science.gov (United States)

Sidick, Erkin; Shi, Fang

2015-01-01

The WFIRST/AFTA 2.4 m space telescope currently under study includes a stellar coronagraph for the imaging and the spectral characterization of extrasolar planets. The coronagraph employs two sequential deformable mirrors (DMs) to compensate for phase and amplitude errors in creating dark holes. DMs are critical elements in high contrast coronagraphs, requiring precision and stability measured in picometers to enable detection of Earth-like exoplanets. Working with a low-order wavefront-sensor the DM that is conjugate to a pupil can also be used to correct low-order wavefront drift during a scientific observation. However, not all actuators in a DM have the same gain. When using such a DM in low-order wavefront sensing and control subsystem, the actuator gain errors introduce high-spatial frequency errors to the DM surface and thus worsen the contrast performance of the coronagraph. We have investigated the effects of actuator gain errors and the actuator command digitization errors on the contrast performance of the coronagraph through modeling and simulations, and will present our results in this paper.

Exhaustive Strategy for Optical Survey of Geosynchronous Region using TAROT Telescopes

Science.gov (United States)

Richard, P.; Yanez, C.; Morand, V.; Verzeni, A.; Boer, M.; Klotz, A.

CNES and CNRS has been working on Optical Space Surveillance and Tracking for many years using the TAROT telescopes network. The goal of the study presented here is to propose an exhaustive strategy for optical survey of geosynchronous region. First, constraints will be defined on perigee and apogee of the orbits for which we are looking for exhaustiveness and then solutions will be explored making the survey in one or several nights using one or several telescopes. The last part of the study proposes solutions to help maintaining exhaustiveness if some observations failed.

Survey Strategy Optimization for the Atacama Cosmology Telescope

Science.gov (United States)

De Bernardis, F.; Stevens, J. R.; Hasselfield, M.; Alonso, D.; Bond, J. R.; Calabrese, E.; Choi, S. K.; Crowley, K. T.; Devlin, M.; Wollack, E. J.

2016-01-01

In recent years there have been significant improvements in the sensitivity and the angular resolution of the instruments dedicated to the observation of the Cosmic Microwave Background (CMB). ACTPol is the first polarization receiver for the Atacama Cosmology Telescope (ACT) and is observing the CMB sky with arcmin resolution over approximately 2000 square degrees. Its upgrade, Advanced ACTPol (AdvACT), will observe the CMB in five frequency bands and over a larger area of the sky. We describe the optimization and implementation of the ACTPol and AdvACT surveys. The selection of the observed fields is driven mainly by the science goals, that is, small angular scale CMB measurements, B-mode measurements and cross-correlation studies. For the ACTPol survey we have observed patches of the southern galactic sky with low galactic foreground emissions which were also chosen to maximize the overlap with several galaxy surveys to allow unique cross-correlation studies. A wider field in the northern galactic cap ensured significant additional overlap with the BOSS spectroscopic survey. The exact shapes and footprints of the fields were optimized to achieve uniform coverage and to obtain cross-linked maps by observing the fields with different scan directions. We have maximized the efficiency of the survey by implementing a close to 24-hour observing strategy, switching between daytime and nighttime observing plans and minimizing the telescope idle time. We describe the challenges represented by the survey optimization for the significantly wider area observed by AdvACT, which will observe roughly half of the low-foreground sky. The survey strategies described here may prove useful for planning future ground-based CMB surveys, such as the Simons Observatory and CMB Stage IV surveys.

Enhnacing the science of the WFIRST coronagraph instrument with post-processing.

Science.gov (United States)

Pueyo, Laurent; WFIRST CGI data analysis and post-processing WG

2018-01-01

We summarize the results of a three years effort investigating how to apply to the WFIRST coronagraph instrument (CGI) modern image analysis methods, now routinely used with ground-based coronagraphs. In this post we quantify the gain associated post-processing for WFIRST-CGI observing scenarios simulated between 2013 and 2017. We also show based one simulations that spectrum of planet can be confidently retrieved using these processing tools with and Integral Field Spectrograph. We then discuss our work using CGI experimental data and quantify coronagraph post-processing testbed gains. We finally introduce stability metrics that are simple to define and measure, and place useful lower bound and upper bounds on the achievable RDI post-processing contrast gain. We show that our bounds hold in the case of the testbed data.

Parfocal wide field near infrared grism design and fabrication for WFIRST

Data.gov (United States)

National Aeronautics and Space Administration — WFIRST will have Hubble image quality with 100x the field area of HST/WFC3. It requires both imaging and, working in the same optical train, a grism allowing...

Requirements and concept design for large earth survey telescope for SEOS

Science.gov (United States)

Mailhot, P.; Bisbee, J.

1975-01-01

The efforts of a one year program of Requirements Analysis and Conceptual Design for the Large Earth Survey Telescope for the Synchronous Earth Observatory Satellite is summarized. A 1.4 meter aperture Cassegrain telescope with 0.6 deg field of view is shown to do an excellent job in satisfying the observational requirements for a wide range of earth resources and meteorological applications. The telescope provides imagery or thermal mapping in ten spectral bands at one time in a field sharing grouping of linear detector arrays. Pushbroom scanning is accomplished by spacecraft slew.

Progress of site survey for large solar telescopes in western China

Science.gov (United States)

Liu, Yu; Song, Tengfei; Zhang, Xuefei; Liu, Shunqing; Zhao, Mingyu; Tian, Zhanjun; Miao, Yuhu; Li, Hongbo; Huang, Jing; Su, Baoyu; Lu, Yongyin; Li, Xiaobo; Song, Qiwu

Excellent sites are necessary for developing and installing ground-based large telescopes. For very-high-resolution solar observations, it had been unclear whether there exist good candidate sites in the west areas in China, including the Tibetan Plateau and the Pamirs Plateau. The project of solar site survey for the next-generation large solar telescopes, i.e., the Chinese Giant Solar Telescope (CGST) and the large coronagraph, has been launched since 2011. Based on the close collaboration among Chinese solar society and the scientists from NSO, HAO and other institutes, we have successfully developed the standard instruments for solar site survey and applied them to more than 50 different sites distributed in Xinjiang, Tibet, Qinghai, Sichuan, Yunnan and Ningxia provinces. We have built two long-term monitoring sites in Tibet and the large Shangri-La to take systematic site data. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that a few potential sites in the large Tibetan areas should obtain the excellent astronomical conditions for our purpose to develop CGST and large coronagraph. We introduce the fresh site survey results in this report.

Editorial: The LAMOST survey at the Guo Shou Jing Telescope

International Nuclear Information System (INIS)

Bland-Hawthorn, Joss

2012-01-01

This special issue is devoted to the LAMOST star/galaxy survey now under way at the Guo Shou Jing Telescope in China. Here I review briefly the LAMOST survey in the context of recent, ongoing and future surveys on the international scene. The primary science goal is to obtain kinematics and abundance information for ten million stars over the Galaxy, far more than all other ground-based surveys combined. This rich trove will provide new insights and understanding about the workings of our Galaxy and its origins.

Sloan Digital Sky Survey photometric telescope automation and observing software

International Nuclear Information System (INIS)

Eric H. Neilsen, Jr.; email = neilsen@fnal.gov

2002-01-01

The photometric telescope (PT) provides observations necessary for the photometric calibration of the Sloan Digital Sky Survey (SDSS). Because the attention of the observing staff is occupied by the operation of the 2.5 meter telescope which takes the survey data proper, the PT must reliably take data with little supervision. In this paper we describe the PT's observing program, MOP, which automates most tasks necessary for observing. MOP's automated target selection is closely modeled on the actions a human observer might take, and is built upon a user interface that can be (and has been) used for manual operation. This results in an interface that makes it easy for an observer to track the activities of the automating procedures and intervene with minimum disturbance when necessary. MOP selects targets from the same list of standard star and calibration fields presented to the user, and chooses standard star fields covering ranges of airmass, color, and time necessary to monitor atmospheric extinction and produce a photometric solution. The software determines when additional standard star fields are unnecessary, and selects survey calibration fields according to availability and priority. Other automated features of MOP, such as maintaining the focus and keeping a night log, are also built around still functional manual interfaces, allowing the observer to be as active in observing as desired; MOP's automated features may be used as tools for manual observing, ignored entirely, or allowed to run the telescope with minimal supervision when taking routine data

Software and control system for the VLT Survey Telescope

International Nuclear Information System (INIS)

Schipani, P; Marty, L; Dall'Ora, M; D'Orsi, S; Argomedo, J; Arcidiacono, C; Farinato, J; Magrin, D; Ragazzoni, R; Umbriaco, G

2013-01-01

The VLT Survey Telescope (VST) has started the regular operations in 2011 after a successful commissioning at Cerro Paranal (Chile), the site which hosts the best facilities for optical astronomy operated by the European Southern Observatory (ESO). After a short description of the instrument, this paper mainly focuses on the telescope control software, which is in charge of the real-time control of the hardware and of the overall coordination of the operations, including pointing and tracking, active optics and presets. We describe the main features of the software implementation in the context of the ESO observatory standards, and the goals reached during the commissioning phase and in the first year of operations.

Requirements and design reference mission for the WFIRST/AFTA coronagraph instrument

Science.gov (United States)

Demers, Richard T.; Dekens, Frank; Calvet, Rob; Chang, Zensheu; Effinger, Robert; Ek, Eric; Hovland, Larry; Jones, Laura; Loc, Anthony; Nemati, Bijan; Noecker, Charley; Neville, Timothy; Pham, Hung; Rud, Mike; Tang, Hong; Villalvazo, Juan

2015-09-01

The WFIRST-AFTA coronagraph instrument takes advantage of AFTAs 2.4-meter aperture to provide novel exoplanet imaging science at approximately the same instrument cost as an Explorer mission. The AFTA coronagraph also matures direct imaging technologies to high TRL for an Exo-Earth Imager in the next decade. The coronagraph Design Reference Mission (DRM) optical design is based on the highly successful High Contrast Imaging Testbed (HCIT), with modifications to accommodate the AFTA telescope design, service-ability, volume constraints, and the addition of an Integral Field Spectrograph (IFS). In order to optimally satisfy the three science objectives of planet imaging, planet spectral characterization and dust debris imaging, the coronagraph is designed to operate in two different modes: Hybrid Lyot Coronagraph or Shaped Pupil Coronagraph. Active mechanisms change pupil masks, focal plane masks, Lyot masks, and bandpass filters to shift between modes. A single optical beam train can thus operate alternatively as two different coronagraph architectures. Structural Thermal Optical Performance (STOP) analysis predicts the instrument contrast with the Low Order Wave Front Control loop closed. The STOP analysis was also used to verify that the optical/structural/thermal design provides the extreme stability required for planet characterization in the presence of thermal disturbances expected in a typical observing scenario. This paper describes the instrument design and the flow down from science requirements to high level engineering requirements.

Requirements and Design Reference Mission for the WFIRST-AFTA Coronagraph Instrument

Science.gov (United States)

Demers, Richard T.; Dekens, Frank; Calvet, Rob; Chang, Zensheu; Effinger, Robert; Ek, Eric; Hovland, Larry; Jones, Laura; Loc, Anthony; Nemati, Bijan;

The Exo-S probe class starshade mission

Science.gov (United States)

Seager, Sara; Turnbull, Margaret; Sparks, William; Thomson, Mark; Shaklan, Stuart B.; Roberge, Aki; Kuchner, Marc; Kasdin, N. Jeremy; Domagal-Goldman, Shawn; Cash, Webster; Warfield, Keith; Lisman, Doug; Scharf, Dan; Webb, David; Trabert, Rachel; Martin, Stefan; Cady, Eric; Heneghan, Cate

2015-09-01

Exo-S is a direct imaging space-based mission to discover and characterize exoplanets. With its modest size, Exo-S bridges the gap between census missions like Kepler and a future space-based flagship direct imaging exoplanet mission. With the ability to reach down to Earth-size planets in the habitable zones of nearly two dozen nearby stars, Exo-S is a powerful first step in the search for and identification of Earth-like planets. Compelling science can be returned at the same time as the technological and scientific framework is developed for a larger flagship mission. The Exo-S Science and Technology Definition Team studied two viable starshade-telescope missions for exoplanet direct imaging, targeted to the $1B cost guideline. The first Exo-S mission concept is a starshade and telescope system dedicated to each other for the sole purpose of direct imaging for exoplanets (The "Starshade Dedicated Mission"). The starshade and commercial, 1.1-m diameter telescope co-launch, sharing the same low-cost launch vehicle, conserving cost. The Dedicated mission orbits in a heliocentric, Earth leading, Earth-drift away orbit. The telescope has a conventional instrument package that includes the planet camera, a basic spectrometer, and a guide camera. The second Exo-S mission concept is a starshade that launches separately to rendezvous with an existing on-orbit space telescope (the "Starshade Rendezvous Mission"). The existing telescope adopted for the study is the WFIRST-AFTA (Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Asset). The WFIRST-AFTA 2.4-m telescope is assumed to have previously launched to a Halo orbit about the Earth-Sun L2 point, away from the gravity gradient of Earth orbit which is unsuitable for formation flying of the starshade and telescope. The impact on WFIRST-AFTA for starshade readiness is minimized; the existing coronagraph instrument performs as the starshade science instrument, while formation guidance is handled by the

Solar System science with the Large Synoptic Survey Telescope

Science.gov (United States)

Jones, Lynne; Brown, Mike; Ivezić, Zeljko; Jurić, Mario; Malhotra, Renu; Trilling, David

2015-11-01

The Large Synoptic Survey Telescope (LSST; http://lsst.org) will be a large-aperture, wide-field, ground-based telescope that will survey half the sky every few nights in six optical bands from 320 to 1050 nm. It will explore a wide range of astrophysical questions, ranging from performing a census of the Solar System, to examining the nature of dark energy. It is currently in construction, slated for first light in 2019 and full operations by 2022.The LSST will survey over 20,000 square degrees with a rapid observational cadence, to typical limiting magnitudes of r~24.5 in each visit (9.6 square degree field of view). Automated software will link the individual detections into orbits; these orbits, as well as precisely calibrated astrometry (~50mas) and photometry (~0.01-0.02 mag) in multiple bandpasses will be available as LSST data products. The resulting data set will have tremendous potential for planetary astronomy; multi-color catalogs of hundreds of thousands of NEOs and Jupiter Trojans, millions of asteroids, tens of thousands of TNOs, as well as thousands of other objects such as comets and irregular satellites of the major planets.LSST catalogs will increase the sample size of objects with well-known orbits 10-100 times for small body populations throughout the Solar System, enabling a major increase in the completeness level of the inventory of most dynamical classes of small bodies and generating new insights into planetary formation and evolution. Precision multi-color photometry will allow determination of lightcurves and colors, as well as spin state and shape modeling through sparse lightcurve inversion. LSST is currently investigating survey strategies to optimize science return across a broad range of goals. To aid in this investigation, we are making a series of realistic simulated survey pointing histories available together with a Python software package to model and evaluate survey detections for a user-defined input population. Preliminary

WFIRST: Retrieval Studies of Directly Imaged Extrasolar Giant Planets

Science.gov (United States)

Marley, Mark; Lupu, Roxana; Lewis, Nikole K.; WFIRST Coronagraph SITs

2018-01-01

The typical direct imaging and spectroscopy target for the WFIRST Coronagraph will be a mature Jupiter-mass giant planet at a few AU from an FGK star. The spectra of such planets is expected to be shaped primarily by scattering from H2O clouds and absorption by gaseous NH3 and CH4. We have computed forward model spectra of such typical planets and applied noise models to understand the quality of photometry and spectra we can expect. Using such simulated datasets we have conducted Markov Chain Monte Carlo and MultiNest retrievals to derive atmospheric abundance of CH4, cloud scattering properties, gravity, and other parameters for various planets and observing modes. Our focus has primarily been to understand which combinations of photometry and spectroscopy at what SNR allow retrievals of atmospheric methane mixing ratios to within a factor of ten of the true value. This is a challenging task for directly imaged planets as the planet mass and radius--and thus surface gravity--are not as well constrained as in the case of transiting planets. We find that for plausible planets and datasets of the quality expected to be obtained by WFIRST it should be possible to place such constraints, at least for some planets. We present some examples of our retrieval results and explain how they have been utilized to help set design requirements on the coronagraph camera and integrated field spectrometer.

A Euclid, LSST and WFIRST Joint Processing Study

Science.gov (United States)

Chary, Ranga-Ram; Joint Processing Working Group

2018-01-01

Euclid, LSST and WFIRST are the flagship cosmological projects of the next decade. By mapping several thousand square degrees of sky and covering the electromagnetic spectrum from the optical to the NIR with (sub-)arcsec resolution, these projects will provide exciting new constraints on the nature of dark energy and dark matter. The ultimate cosmological, astrophysical and time-domain science yield from these missions, which will detect several billions of sources, requires joint processing at the pixel-level. Three U.S. agencies (DOE, NASA and NSF) are supporting an 18-month study which aims to 1) assess the optimal techniques to combine these, and ancillary data sets at the pixel level; 2) investigate options for an interface that will enable community access to the joint data products; and 3) identify the computing and networking infrastructure to properly handle and manipulate these large datasets together. A Joint Processing Working Group (JPWG) is carrying out this study and consists of US-based members from the community and science/data processing centers of each of these projects. Coordination with European partners is envisioned in the future and European Euclid members are involved in the JPWG as observers. The JPWG will scope the effort and resources required to build up the capabilities to support scientific investigations using joint processing in time for the start of science surveys by LSST and Euclid.

A Hubble Space Telescope Survey of the Disk Cluster Population of M31. II. Advanced Camera for Surveys Pointings

Science.gov (United States)

Krienke, O. K.; Hodge, P. W.

2008-01-01

This paper reports on a survey of star clusters in M31 based on archival images from the Hubble Space Telescope. Paper I reported results from images obtained with the Wide Field Planetary Camera 2 (WFPC2) and this paper reports results from the Advanced Camera for Surveys (ACS). The ACS survey has yielded a total of 339 star clusters, 52 of which—mostly globular clusters—were found to have been cataloged previously. As for the previous survey, the luminosity function of the clusters drops steeply for absolute magnitudes fainter than MV = -3 the implied cluster mass function has a turnover for masses less than a few hundred solar masses. The color-integrated magnitude diagram of clusters shows three significant features: (1) a group of very red, luminous objects: the globular clusters, (2) a wide range in color for the fainter clusters, representing a considerable range in age and reddening, and (3) a maximum density of clusters centered approximately at V = 21, B - V = 0.30, V - I = 0.50, where there are intermediate-age, intermediate-mass clusters with ages close to 500 million years and masses of about 2000 solar masses. We give a brief qualitative interpretation of the distribution of clusters in the CMDs in terms of their formation and destruction rates. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for research in astronomy, Inc., under NASA contract NAS 5-26555.

The Cosmic Evolution Through UV Spectroscopy (CETUS) Probe Mission Concept

Science.gov (United States)

Danchi, William; Heap, Sara; Woodruff, Robert; Hull, Anthony; Kendrick, Stephen E.; Purves, Lloyd; McCandliss, Stephan; Kelly Dodson, Greg Mehle, James Burge, Martin Valente, Michael Rhee, Walter Smith, Michael Choi, Eric Stoneking

2018-01-01

CETUS is a mission concept for an all-UV telescope with 3 scientific instruments: a wide-field camera, a wide-field multi-object spectrograph, and a point-source high-resolution and medium resolution spectrograph. It is primarily intended to work with other survey telescopes in the 2020’s (e.g. E-ROSITA (X-ray), LSST, Subaru, WFIRST (optical-near-IR), SKA (radio) to solve major, outstanding problems in astrophysics. In this poster presentation, we give an overview of CETUS key science goals and a progress report on the CETUS mission and instrument design.

Library of Giant Planet Reflection Spectra for WFirst and Future Space Telescopes

Science.gov (United States)

Smith, Adam J. R. W.; Fortney, Jonathan; Morley, Caroline; Batalha, Natasha E.; Lewis, Nikole K.

2018-01-01

Future large space space telescopes will be able to directly image exoplanets in optical light. The optical light of a resolved planet is due to stellar flux reflected by Rayleigh scattering or cloud scattering, with absorption features imprinted due to molecular bands in the planetary atmosphere. To aid in the design of such missions, and to better understand a wide range of giant planet atmospheres, we have built a library of model giant planet reflection spectra, for the purpose of determining effective methods of spectral analysis as well as for comparison with actual imaged objects. This library covers a wide range of parameters: objects are modeled at ten orbital distances between 0.5 AU and 5.0 AU, which ranges from planets too warm for water clouds, out to those that are true Jupiter analogs. These calculations include six metalicities between solar and 100x solar, with a variety of different cloud thickness parameters, and across all possible phase angles.

Driftscan surveys in the 21 cm line with the Arecibo and Nancay telescopes

NARCIS (Netherlands)

Briggs, FH; Sorar, E; KraanKorteweg, RC; vanDriel, W

Driftscan methods are highly efficient, stable techniques for conducting extragalactic surveys in the 21 cm line of neutral hydrogen. Holding the telescope still while the beam scans the sky at the sidereal rate produces exceptionally stable spectral baselines, increased stability for RFI signals,

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.

Detecting and Characterizing Exoplanets with the WFIRST Coronagraph: Colors of Planets in Standard and Designer Bandpasses-SETI

Science.gov (United States)

Turnbull, Margaret

The WFIRST mission is now envisioned to include a coronagraph for the purpose of direct detection of nearby exoplanets, including planets known to exist via radial velocity detection and new discoveries. Assuming that starlight rejection sufficient for planet detection (~1e-9) can be achieved, what can be learned about these planets given a realistic spectral resolution and signal-to-noise ratio? We propose to investigate the potential for WFIRST to efficiently discriminate planets from background sources, and to characterize planets in terms of important diagnostic atmospheric features, using broad- and intermediate band color data. We will map out this capability as a function of signal-to-noise ratio, bandpass location, and bandpass width. Our investigation will place emphasis on gas giants, ice giants, and mini-Neptunes (compatible with current AFTA-C baseline performance specifications), as well as a variety of super-Earths (an AFTA-C "stretch" goal). We will explore a variety of compositions, cloud types, phase angles, and (in the case of super-Earths with semi-transparent atmospheres) surface types. Noiseless spectra generated for these model planets will be passed through (a) standard bandpasses for comparison to prior work and (b) filter transmission curves corresponding to bandpasses of 5-20% over the full range of WFIRST's expected bandpass (400 - 1,000 nm). From this, filter combinations will be used to generate planet colors and find filter sets that most efficiently discriminate between planets and background sources, and between planets of different type. We will then repeat this exercise for S/N levels of 1-1,000 in order to (1) explore the true efficacy of broadband measurements in exoplanet studies, and (2) provide an estimate of total required integration time for a compelling WFIRST exoplanet program. To accomplish this, we will use model spectra for mini-Neptunes, and ice and gas giants of varying composition (Hu et al. 2013), and observed

Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids

Science.gov (United States)

Evans, Nancy Remage; Bond, Howard E.; Schaefer, Gail H.; Mason, Brian D.; Tingle, Evan; Karovska, Margarita; Pillitteri, Ignazio

2016-05-01

We have conducted an imaging survey with the Hubble Space Telescope Wide Field Camera 3 (WFC3) of 70 Galactic Cepheids, typically within 1 kpc, with the aim of finding resolved physical companions. The WFC3 field typically covers the 0.1 pc area where companions are expected. In this paper, we identify 39 Cepheids having candidate companions, based on their positions in color-magnitude diagrams, and having separations ⩾ 5'' from the Cepheids. We use follow-up observations of 14 of these candidates with XMM-Newton, and of one of them with ROSAT, to separate X-ray-active young stars (probable physical companions) from field stars (chance alignments). Our preliminary estimate, based on the optical and X-ray observations, is that only 3% of the Cepheids in the sample have wide companions. Our survey easily detects resolved main-sequence companions as faint as spectral type K. Thus the fact that the two most probable companions (those of FF Aql and RV Sco) are earlier than type K is not simply a function of the detection limit. We find no physical companions having separations larger than 4000 au in the X-ray survey. Two Cepheids are exceptions in that they do have young companions at significantly larger separations (δ Cep and S Nor), but both belong to a cluster or a loose association, so our working model is that they are not gravitationally bound binary members, but rather cluster/association members. All of these properties provide constraints on both star formation and subsequent dynamical evolution. The low frequency of true physical companions at separations > 5'' is confirmed by examination of the subset of the nearest Cepheids and also the density of the fields. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Wavefront control performance modeling with WFIRST shaped pupil coronagraph testbed

Science.gov (United States)

Zhou, Hanying; Nemati, Bijian; Krist, John; Cady, Eric; Kern, Brian; Poberezhskiy, Ilya

2017-09-01

NASA's WFIRST mission includes a coronagraph instrument (CGI) for direct imaging of exoplanets. Significant improvement in CGI model fidelity has been made recently, alongside a testbed high contrast demonstration in a simulated dynamic environment at JPL. We present our modeling method and results of comparisons to testbed's high order wavefront correction performance for the shaped pupil coronagraph. Agreement between model prediction and testbed result at better than a factor of 2 has been consistently achieved in raw contrast (contrast floor, chromaticity, and convergence), and with that comes good agreement in contrast sensitivity to wavefront perturbations and mask lateral shear.

THE GHOSTS SURVEY. I. HUBBLE SPACE TELESCOPE ADVANCED CAMERA FOR SURVEYS DATA

International Nuclear Information System (INIS)

Radburn-Smith, D. J.; Dalcanton, J. J.; De Jong, R. S.; Streich, D.; Vlajic, M.; Seth, A. C.; Bailin, J.; Bell, E. F.; Brown, T. M.; Ferguson, H. C.; Goudfrooij, P.; Holfeltz, S.; Bullock, J. S.; Courteau, S.; Sick, J.; Holwerda, B. W.; Purcell, C.; Zucker, D. B.

2011-01-01

We present an overview of the GHOSTS survey, the largest study to date of the resolved stellar populations in the outskirts of disk galaxies. The sample consists of 14 disk galaxies within 17 Mpc, whose outer disks and halos are imaged with the Hubble Space Telescope Advanced Camera for Surveys (ACS). In the first paper of this series, we describe the sample, explore the benefits of using resolved stellar populations, and discuss our ACS F606W and F814W photometry. We use artificial star tests to assess completeness and use overlapping regions to estimate photometric uncertainties. The median depth of the survey at 50% completeness is 2.7 mag below the tip of the red giant branch (TRGB). We comprehensively explore and parameterize contamination from unresolved background galaxies and foreground stars using archival fields of high-redshift ACS observations. Left uncorrected, these would account for 10 0.65xF814W-19.0 detections per mag per arcsec 2 . We therefore identify several selection criteria that typically remove 95% of the contaminants. Even with these culls, background galaxies are a significant limitation to the surface brightness detection limit which, for this survey, is typically V ∼ 30 mag arcsec -2 . The resulting photometric catalogs are publicly available and contain some 3.1 million stars across 76 ACS fields, predominantly of low extinction. The uniform magnitudes of TRGB stars in these fields enable galaxy distance estimates with 2%-7% accuracy.

Supernovae and cosmology with future European facilities.

Science.gov (United States)

Hook, I M

2013-06-13

Prospects for future supernova surveys are discussed, focusing on the European Space Agency's Euclid mission and the European Extremely Large Telescope (E-ELT), both expected to be in operation around the turn of the decade. Euclid is a 1.2 m space survey telescope that will operate at visible and near-infrared wavelengths, and has the potential to find and obtain multi-band lightcurves for thousands of distant supernovae. The E-ELT is a planned, general-purpose ground-based, 40-m-class optical-infrared telescope with adaptive optics built in, which will be capable of obtaining spectra of type Ia supernovae to redshifts of at least four. The contribution to supernova cosmology with these facilities will be discussed in the context of other future supernova programmes such as those proposed for DES, JWST, LSST and WFIRST.

THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY: STACKED IMAGES AND CATALOGS

International Nuclear Information System (INIS)

Gwyn, Stephen D. J.

2012-01-01

This paper describes the image stacks and catalogs of the Canada-France-Hawaii Telescope Legacy Survey produced using the MegaPipe data pipeline at the Canadian Astronomy Data Centre. The Legacy Survey is divided into two parts. The Deep Survey consists of four fields each of 1 deg 2 , with magnitude limits (50% completeness for point sources) of u = 27.5, g = 27.9, r = 27.7, i = 27.4, and z = 26.2. It contains 1.6 × 10 6 sources. The Wide Survey consists of 150 deg 2 split over four fields, with magnitude limits of u = 26.0, g = 26.5, r = 25.9, i = 25.7, and z = 24.6. It contains 3 × 10 7 sources. This paper describes the calibration, image stacking, and catalog generation process. The images and catalogs are available on the web through several interfaces: normal image and text file catalog downloads, a 'Google Sky' interface, an image cutout service, and a catalog database query service.

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.

The Unique Optical Design of the CTI-II Survey Telescope

Science.gov (United States)

Ackermann, Mark R.; McGraw, J. T.; MacFarlane, M.

2006-12-01

The CCD/Transit Instrument with Innovative Instrumentation (CTI-II) is being developed for precision ground-based astrometric and photometric astronomical observations. The 1.8m telescope will be stationary, near-zenith pointing and will feature a CCD-mosaic array operated in time-delay and integrate (TDI) mode to image a continuous strip of the sky in five bands. The heart of the telescope is a Nasmyth-like bent-Cassegrain optical system optimized to produce near diffraction-limited images with near zero distortion over a circular1.42 deg field. The optical design includes an f/2.2 parabolic ULE primary with no central hole salvaged from the original CTI telescope and adds the requisite hyperbolic secondary, a folding flat and a highly innovative all-spherical, five lens corrector which includes three plano surfaces. The reflective and refractive portions of the design have been optimized as individual but interdependent systems so that the same reflective system can be used with slightly different refractive correctors. At present, two nearly identical corrector designs are being evaluated, one fabricated from BK-7 glass and the other of fused silica. The five lens corrector consists of an air-spaced triplet separated from follow-on air-spaced doublet. Either design produces 0.25 arcsecond images at 83% encircled energy with a maximum of 0.0005% distortion. The innovative five lens corrector design has been applied to other current and planned Cassegrain, RC and super RC optical systems requiring correctors. The basic five lens approach always results in improved performance compared to the original designs. In some cases, the improvement in image quality is small but includes substantial reductions in distortion. In other cases, the improvement in image quality is substantial. Because the CTI-II corrector is designed for a parabolic primary, it might be especially useful for liquid mirror telescopes. We describe and discuss the CTI-II optical design with respect

Origins Space Telescope: 3D infrared surveys of star formation and black hole growth in galaxies over cosmic time

Science.gov (United States)

Pope, Alexandra; Armus, Lee; bradford, charles; Origins Space Telescope STDT

2018-01-01

In the coming decade, new telescope facilities and surveys aim to provide a 3D map of the unobscured Universe over cosmic time. However, much of galaxy formation and evolution occurs behind dust, and is only observable through infrared observations. Previous extragalactic infrared surveys were fundamentally limited to a 2D mapping of the most extreme populations of galaxies due to spatial resolution and sensitivity. The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies sponsored by NASA to provide input to the 2020 Astronomy and Astrophysics Decadal survey. OST is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum, which will achieve spectral line sensitivities up to 1000 times deeper than previous infrared facilities. With powerful instruments such as the Medium Resolution Survey Spectrometer (MRSS), capable of simultaneous imaging and spectroscopy, the extragalactic infrared sky can finally be surveyed in 3D. In addition to spectroscopic redshifts, the rich suite of lines in the infrared provides unique diagnostics of the ongoing star formation (both obscured and unobscured) and the central supermassive black hole growth. In this poster, we present a simulated extragalactic survey with OST/MRSS which will detect millions of galaxies down to well below the knee of the infrared luminosity function. We demonstrate how this survey can map the coeval star formation and black hole growth in galaxies over cosmic time.

A Green Bank Telescope Survey of Large Galactic H II Regions

Science.gov (United States)

Anderson, L. D.; Armentrout, W. P.; Luisi, Matteo; Bania, T. M.; Balser, Dana S.; Wenger, Trey V.

2018-02-01

As part of our ongoing H II Region Discovery Survey (HRDS), we report the Green Bank Telescope detection of 148 new angularly large Galactic H II regions in radio recombination line (RRL) emission. Our targets are located at a declination of δ > -45^\\circ , which corresponds to 266^\\circ > {\\ell }> -20^\\circ at b=0^\\circ . All sources were selected from the Wide-field Infrared Survey Explorer Catalog of Galactic H II Regions, and have infrared angular diameters ≥slant 260\\prime\\prime . The Galactic distribution of these “large” H II regions is similar to that of the previously known sample of Galactic H II regions. The large H II region RRL line width and peak line intensity distributions are skewed toward lower values, compared with that of previous HRDS surveys. We discover seven sources with extremely narrow RRLs 100 {pc}, making them some of the physically largest known H II regions in the Galaxy. This survey completes the HRDS H II region census in the Northern sky, where we have discovered 887 H II regions and more than doubled the size of the previously known census of Galactic H II regions.

S-COSMOS: The Spitzer Legacy Survey of the Hubble Space Telescope ACS 2 deg2 COSMOS Field I: Survey Strategy and First Analysis

Science.gov (United States)

Sanders, D. B.; Salvato, M.; Aussel, H.; Ilbert, O.; Scoville, N.; Surace, J. A.; Frayer, D. T.; Sheth, K.; Helou, G.; Brooke, T.; Bhattacharya, B.; Yan, L.; Kartaltepe, J. S.; Barnes, J. E.; Blain, A. W.; Calzetti, D.; Capak, P.; Carilli, C.; Carollo, C. M.; Comastri, A.; Daddi, E.; Ellis, R. S.; Elvis, M.; Fall, S. M.; Franceschini, A.; Giavalisco, M.; Hasinger, G.; Impey, C.; Koekemoer, A.; Le Fèvre, O.; Lilly, S.; Liu, M. C.; McCracken, H. J.; Mobasher, B.; Renzini, A.; Rich, M.; Schinnerer, E.; Shopbell, P. L.; Taniguchi, Y.; Thompson, D. J.; Urry, C. M.; Williams, J. P.

2007-09-01

The COSMOS Spitzer survey (S-COSMOS) is a Legacy program (Cycles 2+3) designed to carry out a uniform deep survey of the full 2 deg2 COSMOS field in all seven Spitzer bands (3.6, 4.5, 5.6, 8.0, 24.0, 70.0, and 160.0 μm). This paper describes the survey parameters, mapping strategy, data reduction procedures, achieved sensitivities to date, and the complete data set for future reference. We show that the observed infrared backgrounds in the S-COSMOS field are within 10% of the predicted background levels. The fluctuations in the background at 24 μm have been measured and do not show any significant contribution from cirrus, as expected. In addition, we report on the number of asteroid detections in the low Galactic latitude COSMOS field. We use the Cycle 2 S-COSMOS data to determine preliminary number counts, and compare our results with those from previous Spitzer Legacy surveys (e.g., SWIRE, GOODS). The results from this ``first analysis'' confirm that the S-COSMOS survey will have sufficient sensitivity with IRAC to detect ~L* disks and spheroids out to z>~3, and with MIPS to detect ultraluminous starbursts and AGNs out to z~3 at 24 μm and out to z~1.5-2 at 70 and 160 μm. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS 5-26555 also based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan; the XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA; the European Southern Observatory under Large Program 175.A-0839, Chile; Kitt Peak National Observatory, Cerro Tololo Inter-American Observatory, and the National Optical Astronomy Observatory, which are operated by AURA under cooperative agreement with the National Science Foundation; the National Radio Astronomy

VizieR Online Data Catalog: Isaac Newton Telescope Wide Field Survey (CASU 2002)

Science.gov (United States)

Cambridge Astronomical Survey Unit

2002-04-01

The INT Wide Field Survey (WFS) is using the Wide Field Camera (~0.3 square degrees) on the 2.5m Isaac Newton Telescope (INT). The project was initiated in August 1998 and is expected to have a duration of up to five years. Multicolour data will be obtained over 200+ square degrees to a typical depth of ~25 mag (u' through z'). The data is publically accessible via the Cambridge Astronomical Survey Unit to UK and NL communities from day one, with access to the rest of the world after one year. This observation log lists all observations older than the one year proprietary period. (1 data file).

The Atacama Cosmology Telescope: Dusty Star-Forming Galaxies and Active Galactic Nuclei in the Southern Survey

Science.gov (United States)

Marsden, Danica; Gralla, Megan; Marriage, Tobias A.; Switzer, Eric R.; Partridge, Bruce; Massardi, Marcella; Morales, Gustavo; Addison, Graeme; Bond, J. Richard; Crighton, Devin;

A Green Bank Telescope 21cm survey of HI clouds in the Milky Way's nuclear wind

Science.gov (United States)

Denbo, Sara; Endsley, Ryan; Lockman, Felix J.; Ford, Alyson

2015-01-01

Feedback processes such as large-scale galactic winds are thought to be responsible for distributing enriched gas throughout a galaxy and even into the IGM. Such winds have been found in many galaxies with active star formation near their center, and the Fermi bubbles provide evidence for such a nuclear wind in our own Milky Way. A recent 21 cm HI survey by the Australia Telescope Compact Array discovered a population of compact, isolated clouds surrounding the Galactic Center that may be entrained in the Fermi bubble wind. We present data from a survey of 21cm HI over an extended region around the Galactic Center using the Green Bank Telescope. These observations provide more strict constraints on neutral clouds in the Fermi bubble wind, and a more robust description of the parameters of HI clouds (i.e., mass, column density, and lifetime) near the Galactic Center.

The LUVOIR Decadal Mission Concept

Science.gov (United States)

Arney, G. N.; Crooke, J.; Domagal-Goldman, S. D.; Fischer, D.; Peterson, B.; Schmidt, B. E.; Stdt, T. L. T.

2017-12-01

The Large UV-Optical-Infrared (LUVOIR) Surveyor is one of four mission concepts being studied by NASA in preparation for the 2020 Astrophysics Decadal Survey. LUVOIR is a general-purpose space-based observatory with a large aperture in the 8-16 m range and a total bandpass spanning from the far-UV to the near-infrared. This observatory will enable revolutionary new studies in many areas of astronomy, including planetary science within and beyond our Solar System. Because LUVOIR is being considered for the next decadal survey, it must be capable of advancing our understanding of astronomical targets, including exoplanets, far beyond what will be achieved by the next two decades of observations from other space- or ground-based facilities. This means that the mission must move past planet detection, which is happening now with Kepler and ground-based measurements and will continue with TESS (Transiting Exoplanet Survey Satellite) and WFIRST (Wide Field Infrared Survey Telescope). It must also move beyond the chemical characterization of gas giants, which has begun with observations from Spitzer, Hubble, and ground-based telescopes and will greatly advances with the upcoming JWST (James Webb Space Telescope) and WFIRST coronagraph. Therefore, one of LUVOIR's main science objectives will be to directly image rocky Earth-sized planets in the habitable zones of other stars, measure their spectra, analyze the chemistry of their atmospheres, and obtain information about their surfaces. Such observations will allow us to evaluate these worlds' habitability and potential for life. We will review the specific observational strategies needed for astrobiological assessments of exoplanetary environments, including the wavelength range and spectral resolution required for these habitability analyses and biosignature searches. Further, we will discuss how the observational requirements to make measurements of "Earthlike" worlds will allow high-quality observations of a wide

The Large Synoptic Survey Telescope as a Near-Earth Object discovery machine

Science.gov (United States)

Jones, R. Lynne; Slater, Colin T.; Moeyens, Joachim; Allen, Lori; Axelrod, Tim; Cook, Kem; Ivezić, Željko; Jurić, Mario; Myers, Jonathan; Petry, Catherine E.

2018-03-01

Using the most recent prototypes, design, and as-built system information, we test and quantify the capability of the Large Synoptic Survey Telescope (LSST) to discover Potentially Hazardous Asteroids (PHAs) and Near-Earth Objects (NEOs). We empirically estimate an expected upper limit to the false detection rate in LSST image differencing, using measurements on DECam data and prototype LSST software and find it to be about 450 deg-2. We show that this rate is already tractable with current prototype of the LSST Moving Object Processing System (MOPS) by processing a 30-day simulation consistent with measured false detection rates. We proceed to evaluate the performance of the LSST baseline survey strategy for PHAs and NEOs using a high-fidelity simulated survey pointing history. We find that LSST alone, using its baseline survey strategy, will detect 66% of the PHA and 61% of the NEO population objects brighter than H = 22 , with the uncertainty in the estimate of ± 5 percentage points. By generating and examining variations on the baseline survey strategy, we show it is possible to further improve the discovery yields. In particular, we find that extending the LSST survey by two additional years and doubling the MOPS search window increases the completeness for PHAs to 86% (including those discovered by contemporaneous surveys) without jeopardizing other LSST science goals (77% for NEOs). This equates to reducing the undiscovered population of PHAs by additional 26% (15% for NEOs), relative to the baseline survey.

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.

The Whole is Greater than the Sum of the Parts: Optimizing the Joint Science Return from LSST, Euclid and WFIRST

Energy Technology Data Exchange (ETDEWEB)

Jain, B. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Spergel, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Connolly, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Dell' antonio, I. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Frieman, J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Gawiser, E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Gehrels, N. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Gladney, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Heitmann, K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Helou, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Hirata, C. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Ho, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Ivezic, Z. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Jarvis, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kahn, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kalirai, J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kim, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lupton, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Mandelbaum, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Marshall, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Newman, J. A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Postman, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rhodes, J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Strauss, M. A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Tyson, J. A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wood-Vesey, W. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2015-02-02

The scientific opportunity offered by the combination of data from LSST, WFIRST and Euclid goes well beyond the science enabled by any one of the data sets alone. The range in wavelength, angular resolution and redshift coverage that these missions jointly span is remarkable. With major investments in LSST and WFIRST, and partnership with ESA in Euclid, the US has an outstanding scientific opportunity to carry out a combined analysis of these data sets. It is imperative for us to seize it and, together with our European colleagues, prepare for the defining cosmological pursuit of the 21st century. The main argument for conducting a single, high-quality reference co-analysis exercise and carefully documenting the results is the complexity and subtlety of systematics that define this co-analysis. Falling back on many small efforts by different teams in selected fields and for narrow goals will be inefficient, leading to significant duplication of effort.

Proposal for Definitive Survey for Fast Radio Bursts at the Allen Telescope Array

Science.gov (United States)

Harp, Gerald; Tarter, J. C.; Welch, W. J.; Allen Telescope Array Team

2014-01-01

The Allen Telescope Array, a 42-dish radio interferometer in Northern California is now being upgraded with new, more sensitive receivers covering 0.9-18 GHz continuously. Leveraging this frequency coverage and wide field of view, the ATA is a unique and ideal instrument for the discovery and characterization of fast radio bursts (FRBs, discovered at Parkes and Arecibo) and other short-time domain radio phenomena. The field of view (nearly 10 sq. deg. at 1 GHz) allows for a rapid search of 3π steradians with many lookbacks over a period of 2.5 years. The instantaneous wide-frequency range of the upgraded ATA receivers allows sensitive observations at 4 simultaneous frequency ranges (for example, 0.9 - 1.5 GHz, 1.6-2.2 GHz, 2.5-3.1 GHz, and 4.6-5.2 GHz, full Stokes); something not possible at any other major telescope. This enables very accurate dispersion measure and spectral index characterization of ms-timescale bursts (or other time-variable activity) with a localization accuracy ~20" for SNR > 10 (all FRBs discovered to date would meet this criterium). We discuss the new digital processing system required to perform this survey, with a plan to capture ~400 FRB events during the survey period of performance , based on current event-rate estimates of 10^4 events/sky/day.

A blind green bank telescope millimeter-wave survey for redshifted molecular absorption

Energy Technology Data Exchange (ETDEWEB)

Kanekar, N.; Gupta, A. [National Centre for Radio Astrophysics, TIFR, Ganeshkhind, Pune 411007 (India); Carilli, C. L. [National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801 (United States); Stocke, J. T. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Willett, K. W., E-mail: nkanekar@ncra.tifr.res.in [School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

2014-02-10

We present the methodology for 'blind' millimeter-wave surveys for redshifted molecular absorption in the CO/HCO{sup +} rotational lines. The frequency range 30-50 GHz appears optimal for such surveys, providing sensitivity to absorbers at z ≳ 0.85. It is critical that the survey is 'blind', i.e., based on a radio-selected sample, including sources without known redshifts. We also report results from the first large survey of this kind, using the Q-band receiver on the Green Bank Telescope (GBT) to search for molecular absorption toward 36 sources, 3 without known redshifts, over the frequency range 39.6-49.5 GHz. The GBT survey has a total redshift path of Δz ≈ 24, mostly at 0.81 < z < 1.91, and a sensitivity sufficient to detect equivalent H{sub 2} column densities ≳ 3 × 10{sup 21} cm{sup –2} in absorption at 5σ significance (using CO-to-H{sub 2} and HCO{sup +}-to-H{sub 2} conversion factors of the Milky Way). The survey yielded no confirmed detections of molecular absorption, yielding the 2σ upper limit n(z = 1.2) < 0.15 on the redshift number density of molecular gas at column densities N(H{sub 2}) ≳ 3 × 10{sup 21} cm{sup –2}.

CANDELS : THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY-THE HUBBLE SPACE TELESCOPE OBSERVATIONS, IMAGING DATA PRODUCTS, AND MOSAICS

NARCIS (Netherlands)

Koekemoer, Anton M.; Faber, S. M.; Ferguson, Henry C.; Grogin, Norman A.; Kocevski, Dale D.; Koo, David C.; Lai, Kamson; Lotz, Jennifer M.; Lucas, Ray A.; McGrath, Elizabeth J.; Ogaz, Sara; Rajan, Abhijith; Riess, Adam G.; Rodney, Steve A.; Strolger, Louis; Casertano, Stefano; Castellano, Marco; Dahlen, Tomas; Dickinson, Mark; Dolch, Timothy; Fontana, Adriano; Giavalisco, Mauro; Grazian, Andrea; Guo, Yicheng; Hathi, Nimish P.; Huang, Kuang-Han; van der Wel, Arjen; Yan, Hao-Jing; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frederic; Brown, Thomas M.; Caputi, Karina I.; Cassata, Paolo; Challis, Peter J.; Chary, Ranga-Ram; Cheung, Edmond; Cirasuolo, Michele; Conselice, Christopher J.; Cooray, Asantha Roshan; Croton, Darren J.; Daddi, Emanuele; Dave, Romeel; de Mello, Duilia F.; de Ravel, Loic; Dekel, Avishai; Donley, Jennifer L.; Dunlop, James S.; Dutton, Aaron A.; Elbaz, David; Fazio, Giovanni G.; Filippenko, Alexei V.; Finkelstein, Steven L.; Frazer, Chris; Gardner, Jonathan P.; Garnavich, Peter M.; Gawiser, Eric; Gruetzbauch, Ruth; Hartley, Will G.; Haeussler, Boris; Herrington, Jessica; Hopkins, Philip F.; Huang, Jia-Sheng; Jha, Saurabh W.; Johnson, Andrew; Kartaltepe, Jeyhan S.; Khostovan, Ali A.; Kirshner, Robert P.; Lani, Caterina; Lee, Kyoung-Soo; Li, Weidong; Madau, Piero; McCarthy, Patrick J.; McIntosh, Daniel H.; McLure, Ross J.; McPartland, Conor; Mobasher, Bahram; Moreira, Heidi; Mortlock, Alice; Moustakas, Leonidas A.; Mozena, Mark; Nandra, Kirpal; Newman, Jeffrey A.; Nielsen, Jennifer L.; Niemi, Sami; Noeske, Kai G.; Papovich, Casey J.; Pentericci, Laura; Pope, Alexandra; Primack, Joel R.; Ravindranath, Swara; Reddy, Naveen A.; Renzini, Alvio; Rix, Hans-Walter; Robaina, Aday R.; Rosario, David J.; Rosati, Piero; Salimbeni, Sara; Scarlata, Claudia; Siana, Brian; Simard, Luc; Smidt, Joseph; Snyder, Diana; Somerville, Rachel S.; Spinrad, Hyron; Straughn, Amber N.; Telford, Olivia; Teplitz, Harry I.; Trump, Jonathan R.; Vargas, Carlos; Villforth, Carolin; Wagner, Cory R.; Wandro, Pat; Wechsler, Risa H.; Weiner, Benjamin J.; Wiklind, Tommy; Wild, Vivienne; Wilson, Grant; Wuyts, Stijn; Yun, Min S.

2011-01-01

This paper describes the Hubble Space Telescope imaging data products and data reduction procedures for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). This survey is designed to document the evolution of galaxies and black holes at z approximate to 1.5-8, and to study

3D-HST: A Wide-field Grism Spectroscopic Survey with the Hubble Space Telescope

Science.gov (United States)

Brammer, Gabriel B.; van Dokkum, Pieter G.; Franx, Marijn; Fumagalli, Mattia; Patel, Shannon; Rix, Hans-Walter; Skelton, Rosalind E.; Kriek, Mariska; Nelson, Erica; Schmidt, Kasper B.; Bezanson, Rachel; da Cunha, Elisabete; Erb, Dawn K.; Fan, Xiaohui; Förster Schreiber, Natascha; Illingworth, Garth D.; Labbé, Ivo; Leja, Joel; Lundgren, Britt; Magee, Dan; Marchesini, Danilo; McCarthy, Patrick; Momcheva, Ivelina; Muzzin, Adam; Quadri, Ryan; Steidel, Charles C.; Tal, Tomer; Wake, David; Whitaker, Katherine E.; Williams, Anna

2012-06-01

We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the physical processes that shape galaxies in the distant universe. 3D-HST provides rest-frame optical spectra for a sample of ~7000 galaxies at 1 < z < 3.5, the epoch when ~60% of all star formation took place, the number density of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in galaxies today must have emerged. 3D-HST will cover three quarters (625 arcmin2) of the CANDELS Treasury survey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L grism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of ~5 per resolution element at H 140 ~ 23.1 and a 5σ emission-line sensitivity of ~5 × 10-17 erg s-1 cm-2 for typical objects, improving by a factor of ~2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide continuous wavelength coverage from 1.1 to 1.6 μm at a spatial resolution of ~0farcs13, which, combined with their depth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary reduction and analysis of the grism observations, including emission-line and redshift measurements from combined fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis yields redshift estimates with a precision of σ(z) = 0.0034(1 + z), or σ(v) ≈ 1000 km s-1. We illustrate how the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types of objects, including a quasar at z = 4.7, quiescent galaxies at z ~ 2, and the most distant T-type brown dwarf star known. The combination of the CANDELS and 3D-HST surveys will provide the definitive imaging and spectroscopic data set for studies of the 1 < z < 3.5 universe until the launch of the James Webb Space

Cosmology with the Large Synoptic Survey Telescope: an overview

Science.gov (United States)

Zhan, Hu; Tyson, J. Anthony

2018-06-01

The Large Synoptic Survey Telescope (LSST) is a high étendue imaging facility that is being constructed atop Cerro Pachón in northern Chile. It is scheduled to begin science operations in 2022. With an ( effective) aperture, a novel three-mirror design achieving a seeing-limited field of view, and a 3.2 gigapixel camera, the LSST has the deep-wide-fast imaging capability necessary to carry out an survey in six passbands (ugrizy) to a coadded depth of over 10 years using of its observational time. The remaining of the time will be devoted to considerably deeper and faster time-domain observations and smaller surveys. In total, each patch of the sky in the main survey will receive 800 visits allocated across the six passbands with exposure visits. The huge volume of high-quality LSST data will provide a wide range of science opportunities and, in particular, open a new era of precision cosmology with unprecedented statistical power and tight control of systematic errors. In this review, we give a brief account of the LSST cosmology program with an emphasis on dark energy investigations. The LSST will address dark energy physics and cosmology in general by exploiting diverse precision probes including large-scale structure, weak lensing, type Ia supernovae, galaxy clusters, and strong lensing. Combined with the cosmic microwave background data, these probes form interlocking tests on the cosmological model and the nature of dark energy in the presence of various systematics. The LSST data products will be made available to the US and Chilean scientific communities and to international partners with no proprietary period. Close collaborations with contemporaneous imaging and spectroscopy surveys observing at a variety of wavelengths, resolutions, depths, and timescales will be a vital part of the LSST science program, which will not only enhance specific studies but, more importantly, also allow a more complete understanding of the Universe through different windows.

Weak-lensing mass calibration of the Atacama Cosmology Telescope equatorial Sunyaev-Zeldovich cluster sample with the Canada-France-Hawaii telescope stripe 82 survey

Energy Technology Data Exchange (ETDEWEB)

Battaglia, N.; Miyatake, H.; Hasselfield, M.; Calabrese, E.; Ferrara, S.; Hložek, R. [Dept. of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Leauthaud, A. [Kavli IPMU (WPI), UTIAS, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Gralla, M.B.; Crichton, D. [Dept. of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Allison, R.; Dunkley, J. [Dept. of Astrophysics, University of Oxford, Oxford OX1 3RH (United Kingdom); Bond, J.R. [Canadian Institute for Theoretical Astrophysics, Toronto, ON M5S 3H8 (Canada); Devlin, M.J. [Dept. of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Dünner, R. [Dept. de Astronomía y Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, Santiago (Chile); Erben, T. [Argelander-Institut für Astronomie, University of Bonn, 53121 Bonn (Germany); Halpern, M.; Hincks, A.D. [Dept. of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z4 (Canada); Hilton, M. [Astrophysics and Cosmology Research Unit, School of Mathematical, Statistics and Computer Science, University of KwaZulu-Natal, Durban, 4041 (South Africa); Hill, J.C. [Dept. of Astronomy, Columbia University, New York, NY 10027 (United States); Huffenberger, K.M., E-mail: nbatta@astro.princeton.edu [Dept. of Physics, Florida State University, Tallahassee, FL 32306 (United States); and others

2016-08-01

Mass calibration uncertainty is the largest systematic effect for using clusters of galaxies to constrain cosmological parameters. We present weak lensing mass measurements from the Canada-France-Hawaii Telescope Stripe 82 Survey for galaxy clusters selected through their high signal-to-noise thermal Sunyaev-Zeldovich (tSZ) signal measured with the Atacama Cosmology Telescope (ACT). For a sample of 9 ACT clusters with a tSZ signal-to-noise greater than five the average weak lensing mass is (4.8±0.8) ×10{sup 14} M{sub ⊙}, consistent with the tSZ mass estimate of (4.70±1.0) ×10{sup 14} M{sub ⊙} which assumes a universal pressure profile for the cluster gas. Our results are consistent with previous weak-lensing measurements of tSZ-detected clusters from the Planck satellite. When comparing our results, we estimate the Eddington bias correction for the sample intersection of Planck and weak-lensing clusters which was previously excluded.

Weak-Lensing Mass Calibration of the Atacama Cosmology Telescope Equatorial Sunyaev-Zeldovich Cluster Sample with the Canada-France-Hawaii Telescope Stripe 82 Survey

Science.gov (United States)

Battaglia, N.; Leauthaud, A.; Miyatake, H.; Hasseleld, M.; Gralla, M. B.; Allison, R.; Bond, J. R.; Calabrese, E.; Crichton, D.; Devlin, M. J.;

Weak-lensing mass calibration of the Atacama Cosmology Telescope equatorial Sunyaev-Zeldovich cluster sample with the Canada-France-Hawaii telescope stripe 82 survey

International Nuclear Information System (INIS)

Battaglia, N.; Miyatake, H.; Hasselfield, M.; Calabrese, E.; Ferrara, S.; Hložek, R.; Leauthaud, A.; Gralla, M.B.; Crichton, D.; Allison, R.; Dunkley, J.; Bond, J.R.; Devlin, M.J.; Dünner, R.; Erben, T.; Halpern, M.; Hincks, A.D.; Hilton, M.; Hill, J.C.; Huffenberger, K.M.

2016-01-01

Mass calibration uncertainty is the largest systematic effect for using clusters of galaxies to constrain cosmological parameters. We present weak lensing mass measurements from the Canada-France-Hawaii Telescope Stripe 82 Survey for galaxy clusters selected through their high signal-to-noise thermal Sunyaev-Zeldovich (tSZ) signal measured with the Atacama Cosmology Telescope (ACT). For a sample of 9 ACT clusters with a tSZ signal-to-noise greater than five the average weak lensing mass is (4.8±0.8) ×10 14 M ⊙ , consistent with the tSZ mass estimate of (4.70±1.0) ×10 14 M ⊙ which assumes a universal pressure profile for the cluster gas. Our results are consistent with previous weak-lensing measurements of tSZ-detected clusters from the Planck satellite. When comparing our results, we estimate the Eddington bias correction for the sample intersection of Planck and weak-lensing clusters which was previously excluded.

Complete Calibration of the Color-Redshift Relation (C3R2): A Critical Foundation for Weak Lensing Cosmology with Euclid and WFIRST

Science.gov (United States)

Masters, Daniel C.; Stern, Daniel; Cohen, Judy; Capak, Peter

2018-01-01

A primary objective of both WFIRST and Euclid is to provide a 3D map of the distribution of matter across a significant fraction of the universe from the weak lensing shear field. Doing so will require accurate redshifts to the billions of galaxies that comprise the weak lensing samples of these surveys; achieving the required accuracy is a “tall pole” challenge for both missions. Here we present the ongoing Complete Calibration of the Color-Redshift Relation (C3R2) survey, designed specifically to calibrate the empirical galaxy color-redshift relation to Euclid depth. C3R2 is an ambitious Keck spectroscopy program, with a survey design based on a machine learning technique that allows us to optimally select the most important galaxies to sample the full range of galaxy colors. C3R2 is a multi-center program with time from all the primary Keck partners (Caltech, UC, Hawaii, and NASA), with a total of 34.5 Keck nights allocated to this project. Data Release 1, including 1283 high-confidence spectroscopic redshifts, is published as Masters, Stern, Cohen, Capak, et al. (2017), and we are currently completing Data Release 2, which will include >2000 additional high-confidence spectroscopic redshifts (Masters et al., in prep.). We will discuss current results and prospects for the survey going forward.

Sulfur Hazes in Giant Exoplanet Atmospheres: Impacts on Reflected Light Spectra

Energy Technology Data Exchange (ETDEWEB)

Gao, Peter; Marley, Mark S.; Zahnle, Kevin [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Robinson, Tyler D. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA 95064 (United States); Lewis, Nikole K., E-mail: pgao@caltech.edu [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

2017-03-01

Recent work has shown that sulfur hazes may arise in the atmospheres of some giant exoplanets, due to the photolysis of H{sub 2}S. We investigate the impact such a haze would have on an exoplanet’s geometric albedo spectrum and how it may affect the direct imaging results of the Wide Field Infrared Survey Telescope ( WFIRST ), a planned NASA space telescope. For temperate (250 K <  T {sub eq} < 700 K) Jupiter-mass planets, photochemical destruction of H{sub 2}S results in the production of ∼1 ppmv of S{sub 8} between 100 and 0.1 mbar, which, if cool enough, will condense to form a haze. Nominal haze masses are found to drastically alter a planet’s geometric albedo spectrum: whereas a clear atmosphere is dark at wavelengths between 0.5 and 1 μ m, due to molecular absorption, the addition of a sulfur haze boosts the albedo there to ∼0.7, due to scattering. Strong absorption by the haze shortward of 0.4 μ m results in albedos <0.1, in contrast to the high albedos produced by Rayleigh scattering in a clear atmosphere. As a result, the color of the planet shifts from blue to orange. The existence of a sulfur haze masks the molecular signatures of methane and water, thereby complicating the characterization of atmospheric composition. Detection of such a haze by WFIRST is possible, though discriminating between a sulfur haze and any other highly reflective, high-altitude scatterer will require observations shortward of 0.4 μ m, which is currently beyond WFIRST ’s design.

EXPECTED LARGE SYNOPTIC SURVEY TELESCOPE (LSST) YIELD OF ECLIPSING BINARY STARS

International Nuclear Information System (INIS)

Prsa, Andrej; Pepper, Joshua; Stassun, Keivan G.

2011-01-01

In this paper, we estimate the Large Synoptic Survey Telescope (LSST) yield of eclipsing binary stars, which will survey ∼20,000 deg 2 of the southern sky during a period of 10 years in six photometric passbands to r ∼ 24.5. We generate a set of 10,000 eclipsing binary light curves sampled to the LSST time cadence across the whole sky, with added noise as a function of apparent magnitude. This set is passed to the analysis-of-variance period finder to assess the recoverability rate for the periods, and the successfully phased light curves are passed to the artificial-intelligence-based pipeline ebai to assess the recoverability rate in terms of the eclipsing binaries' physical and geometric parameters. We find that, out of ∼24 million eclipsing binaries observed by LSST with a signal-to-noise ratio >10 in mission lifetime, ∼28% or 6.7 million can be fully characterized by the pipeline. Of those, ∼25% or 1.7 million will be double-lined binaries, a true treasure trove for stellar astrophysics.

Large Synoptic Survey Telescope: From Science Drivers to Reference Design

Energy Technology Data Exchange (ETDEWEB)

Ivezic, Z.; Axelrod, T.; Brandt, W.N.; Burke, D.L.; Claver, C.F.; Connolly, A.; Cook, K.H.; Gee, P.; Gilmore, D.K.; Jacoby, S.H.; Jones, R.L.; Kahn, S.M.; Kantor, J.P.; Krabbendam, V.; Lupton, R.H.; Monet, D.G.; Pinto, P.A.; Saha, A.; Schalk, T.L.; Schneider, D.P.; Strauss, Michael A.; /Washington U., Seattle, Astron. Dept. /LSST Corp. /Penn State U., Astron. Astrophys. /KIPAC, Menlo Park /NOAO, Tucson /LLNL, Livermore /UC, Davis /Princeton U., Astrophys. Sci. Dept. /Naval Observ., Flagstaff /Arizona U., Astron. Dept. - Steward Observ. /UC, Santa Cruz /Harvard U. /Johns Hopkins U. /Illinois U., Urbana

2011-10-14

In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST). LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pachon in Northern Chile. The current baseline design, with an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg{sup 2} field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image quality, as well as superb astrometric and photometric accuracy. The survey area will include 30,000 deg{sup 2} with {delta} < +34.5{sup o}, and will be imaged multiple times in six bands, ugrizy, covering the wavelength range 320-1050 nm. About 90% of the observing time will be devoted to a deep-wide-fast survey mode which will observe a 20,000 deg{sup 2} region about 1000 times in the six bands during the anticipated 10 years of operation. These data will result in databases including 10 billion galaxies and a similar number of stars, and will serve the majority of science programs. The remaining 10% of the observing time will be allocated to special programs such as Very Deep and Very Fast time domain surveys. We describe how the

Large Synoptic Survey Telescope: From science drivers to reference design

Directory of Open Access Journals (Sweden)

Ivezić Ž.

2008-01-01

Full Text Available In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next- generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST. LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pachon in Northern Chile. The current baseline design, with an 8.4 m (6.5 m effective primary mirror, a 9.6 deg2 field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image quality, as well as superb astrometric and photometric accuracy. The survey area will include 30,000 deg2 with δ < +34.5◦ , and will be imaged multiple times in six bands, ugrizy, covering the wavelength range 320-1050 nm. About 90% of the observing time will be devoted to a deep- wide-fast survey mode which will observe a 20,000 deg2 region about 1000 times in the six bands during the anticipated 10 years of operation. These data will result in databases including 10 billion galaxies and a similar number of stars, and will serve the majority of science programs. The remaining 10% of the observing time will be allocated to special programs such as Very Deep and Very Fast time domain surveys. We describe how the LSST

Large Synoptic Survey Telescope: From Science Drivers To Reference Design

Directory of Open Access Journals (Sweden)

Ivezić, Ž.

2008-06-01

Full Text Available In the history of astronomy, major advances in our understanding of the Universe have come from dramatic improvements in our ability to accurately measure astronomical quantities. Aided by rapid progress in information technology, current sky surveys are changing the way we view and study the Universe. Next-generation surveys will maintain this revolutionary progress. We focus here on the most ambitious survey currently planned in the visible band, the Large Synoptic Survey Telescope (LSST. LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: constraining dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. It will be a large, wide-field ground-based system designed to obtain multiple images covering the sky that is visible from Cerro Pach'{o}n in Northern Chile. The current baseline design, with an 8.4, m (6.5, m effective primary mirror, a 9.6 deg$^2$ field of view, and a 3,200 Megapixel camera, will allow about 10,000 square degrees of sky to be covered using pairs of 15-second exposures in two photometric bands every three nights on average. The system is designed to yield high image quality, as well as superb astrometric and photometric accuracy. The survey area will include 30,000 deg$^2$ with $delta<+34.5^circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\\% of the observing time will be devoted to a deep-wide-fast survey mode which will observe a 20,000 deg$^2$ region about 1000 times in the six bands during the anticipated 10 years of operation. These data will result in databases including 10 billion galaxies and a similar number of stars, and will serve the majority of science programs. The remaining 10\\% of the observing time will be allocated to special programs such as Very Deep and Very Fast time domain surveys. We

Bayesian galaxy shape measurement for weak lensing surveys - III. Application to the Canada-France-Hawaii Telescope Lensing Survey

Science.gov (United States)

Miller, L.; Heymans, C.; Kitching, T. D.; van Waerbeke, L.; Erben, T.; Hildebrandt, H.; Hoekstra, H.; Mellier, Y.; Rowe, B. T. P.; Coupon, J.; Dietrich, J. P.; Fu, L.; Harnois-Déraps, J.; Hudson, M. J.; Kilbinger, M.; Kuijken, K.; Schrabback, T.; Semboloni, E.; Vafaei, S.; Velander, M.

2013-03-01

A likelihood-based method for measuring weak gravitational lensing shear in deep galaxy surveys is described and applied to the Canada-France-Hawaii Telescope (CFHT) Lensing Survey (CFHTLenS). CFHTLenS comprises 154 deg2 of multi-colour optical data from the CFHT Legacy Survey, with lensing measurements being made in the i' band to a depth i'AB noise ratio νSN ≳ 10. The method is based on the lensfit algorithm described in earlier papers, but here we describe a full analysis pipeline that takes into account the properties of real surveys. The method creates pixel-based models of the varying point spread function (PSF) in individual image exposures. It fits PSF-convolved two-component (disc plus bulge) models to measure the ellipticity of each galaxy, with Bayesian marginalization over model nuisance parameters of galaxy position, size, brightness and bulge fraction. The method allows optimal joint measurement of multiple, dithered image exposures, taking into account imaging distortion and the alignment of the multiple measurements. We discuss the effects of noise bias on the likelihood distribution of galaxy ellipticity. Two sets of image simulations that mirror the observed properties of CFHTLenS have been created to establish the method's accuracy and to derive an empirical correction for the effects of noise bias.

Spectral and Wavefront Error Performance of WFIRST/AFTA Prototype Filters

Science.gov (United States)

Quijada, Manuel; Seide, Laurie; Marx, Cathy; Pasquale, Bert; McMann, Joseph; Hagopian, John; Dominguez, Margaret; Gong, Qian; Morey, Peter

2016-01-01

The Cycle 5 design baseline for the Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Assets (WFIRSTAFTA) instrument includes a single wide-field channel (WFC) instrument for both imaging and slit-less spectroscopy. The only routinely moving part during scientific observations for this wide-field channel is the element wheel (EW) assembly. This filter-wheel assembly will have 8 positions that will be populated with 6 bandpass filters, a blank position, and a Grism that will consist of a three-element assembly to disperse the full field with an undeviated central wavelength for galaxy redshift surveys. All filter elements in the EW assembly will be made out of fused silica substrates (110 mm diameter) that will have the appropriate bandpass coatings according to the filter designations (Z087, Y106, J129, H158, F184, W149 and Grism). This paper presents and discusses the performance (including spectral transmission and reflectedtransmitted wavefront error measurements) of a subset of bandpass filter coating prototypes that are based on the WFC instrument filter compliment. The bandpass coating prototypes that are tested in this effort correspond to the Z087, W149, and Grism filter elements. These filter coatings have been procured from three different vendors to assess the most challenging aspects in terms of the in-band throughput, out of band rejection (including the cut-on and cutoff slopes), and the impact the wavefront error distortions of these filter coatings will have on the imaging performance of the de-field channel in the WFIRSTAFTA observatory.

Free-floating planets from microlensing

Science.gov (United States)

Sumi, Takahiro

2014-06-01

Gravitational microlensing has an unique sensitivity to exoplanets at outside of the snow-line and even exoplanets unbound to any host stars because the technique does not rely on any light from the host but the gravity of the lens. MOA and OGLE collaborations reported the discovery of a population of unbound or distant Jupiter-mass objects, which are almost twice (1.8_{-0.8}^{+1.7}) as common as main-sequence stars, based on two years of gravitational microlensing survey observations toward the Galactic Bulge. These planetary-mass objects have no host stars that can be detected within about ten astronomical units by gravitational microlensing. However a comparison with constraints from direct imaging suggests that most of these planetary-mass objects are not bound to any host star. The such short-timescale unbound planetary candidates have been detected with the similar rate in on-going observations and these groups are working to update the analysis with larger statistics. Recently, there are also discoveries of free-floating planetary mass objects by the direct imaging in young star-forming regions and in the moving groups, but these objects are limited to massive objects of 3 to 15 Jupiter masses.They are more massive than the population found by microlensing. So they may be a different population with the different formation process, either similar with that of stars and brown dwarfs, or formed in proto-planetary disks and subsequently scattered into unbound or very distant orbits. It is important to fill the gap of these mass ranges to fully understand these populations. The Wide Field Infrared Survey Telescope (WFIRST) is the highest ranked recommendation for a large space mission in the recent New Worlds, New Horizons (NWNH) in Astronomy and Astrophysics 2010 Decadal Survey. Exoplanet microlensing program is one of the primary science of WFIRST. WFIRST will find about 3000 bound planets and 2000 unbound planets by the high precision continuous survey 15 min

SIGGMA: A SURVEY OF IONIZED GAS IN THE GALAXY, MADE WITH THE ARECIBO TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Liu, B. [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); McIntyre, T. [University of New Mexico, Albuquerque, NM 87131 (United States); Terzian, Y. [Cornell University, Ithaca, NY 14853 (United States); Minchin, R. [Arecibo Observatory, HC03 Box 53995, Arecibo 00612, PR (United States); Anderson, L. [West Virginia University, Morgantown, WV 26506 (United States); Churchwell, E. [University of Wisconsin-Madison, Madison, WI 53706 (United States); Lebron, M. [University of Puerto Rico, P.O. Box 23323, 00931-3323, San Juan (Puerto Rico); Roshi, D. Anish [National Radio Astronomy Observatory, Green Bank and Charlottesville, VA 22903 (United States)

2013-10-01

A Survey of Ionized Gas in the Galaxy, made with the Arecibo telescope (SIGGMA), uses the Arecibo L-band Feed Array (ALFA) to fully sample the Galactic plane (30 Degree-Sign {<=} l {<=} 75 Degree-Sign and -2 Degree-Sign {<=} b {<=} 2 Degree-Sign ; 175 Degree-Sign {<=} l {<=} 207 Degree-Sign and -2 Degree-Sign {<=} b {<=} 1 Degree-Sign ) observable with the telescope in radio recombination lines (RRLs). Processed data sets are being produced in the form of data cubes of 2 Degree-Sign (along l) Multiplication-Sign 4 Degree-Sign (along b) Multiplication-Sign 151 (number of channels), archived and made public. The 151 channels cover a velocity range of 600 km s{sup -1} and the velocity resolution of the survey changes from 4.2 km s{sup -1} to 5.1 km s{sup -1} from the lowest frequency channel to the highest frequency channel. RRL maps with 3.'4 resolution and a line flux density sensitivity of {approx}0.5 mJy will enable us to identify new H II regions, measure their electron temperatures, study the physics of photodissociation regions with carbon RRLs, and investigate the origin of the extended low-density medium. Twelve Hn{alpha} lines fall within the 300 MHz bandpass of ALFA; they are resampled to a common velocity resolution to improve the signal-to-noise ratio (S/N) by a factor of three or more and preserve the line width. SIGGMA will produce the most sensitive fully sampled RRL survey to date. Here, we discuss the observing and data reduction techniques in detail. A test observation toward the H II region complex S255/S257 has detected Hn{alpha} and Cn{alpha} lines with S/N > 10.

First results of the Test-Bed Telescopes (TBT) project: Cebreros telescope commissioning

Science.gov (United States)

Ocaña, Francisco; Ibarra, Aitor; Racero, Elena; Montero, Ángel; Doubek, Jirí; Ruiz, Vicente

2016-07-01

The TBT project is being developed under ESA's General Studies and Technology Programme (GSTP), and shall implement a test-bed for the validation of an autonomous optical observing system in a realistic scenario within the Space Situational Awareness (SSA) programme of the European Space Agency (ESA). The goal of the project is to provide two fully robotic telescopes, which will serve as prototypes for development of a future network. The system consists of two telescopes, one in Spain and the second one in the Southern Hemisphere. The telescope is a fast astrograph with a large Field of View (FoV) of 2.5 x 2.5 square-degrees and a plate scale of 2.2 arcsec/pixel. The tube is mounted on a fast direct-drive mount moving with speed up to 20 degrees per second. The focal plane hosts a 2-port 4K x 4K back-illuminated CCD with readout speeds up to 1MHz per port. All these characteristics ensure good survey performance for transients and fast moving objects. Detection software and hardware are optimised for the detection of NEOs and objects in high Earth orbits (objects moving from 0.1-40 arcsec/second). Nominal exposures are in the range from 2 to 30 seconds, depending on the observational strategy. Part of the validation scenario involves the scheduling concept integrated in the robotic operations for both sensors. Every night it takes all the input needed and prepares a schedule following predefined rules allocating tasks for the telescopes. Telescopes are managed by RTS2 control software, that performs the real-time scheduling of the observation and manages all the devices at the observatory.1 At the end of the night the observing systems report astrometric positions and photometry of the objects detected. The first telescope was installed in Cebreros Satellite Tracking Station in mid-2015. It is currently in the commissioning phase and we present here the first results of the telescope. We evaluate the site characteristics and the performance of the TBT Cebreros

Analysis of the GPS Observations of the Site Survey at Sheshan 25-m Radio Telescope in August 2008

Science.gov (United States)

Liu, L.; Cheng, Z. Y.; Li, J. L.

2010-01-01

The processing of the GPS observations of the site survey at Sheshan 25-m radio telescope in August 2008 is reported. Because each session in this survey is only about six hours, not allowing the subdaily high frequency variations in the station coordinates to be reasonably smoothed, and because there are serious cycle slips in the observations and a large volume of data would be rejected during the software automatic adjustment of slips, the ordinary solution settings of GAMIT needed to be adjusted by loosening the constraints in the a priori coordinates to 10 m, adopting the "quick" mode in the solution iteration, and combining Cview manual operation with GAMIT automatic fixing of cycle slips. The resulting coordinates of the local control polygon in ITRF2005 are then compared with conventional geodetic results. Due to large rotations and translations in the two sets of coordinates (geocentric versus quasi-topocentric), the seven transformation parameters cannot be solved for directly. With various trial solutions it is shown that with a partial pre-removal of the large parameters, high precision transformation parameters can be obtained with post-fit residuals at the millimeter level. This analysis is necessary to prepare the follow-on site and transformation survey of the VLBI and SLR telescopes at Sheshan

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.

Computer-aided discovery of debris disk candidates: A case study using the Wide-Field Infrared Survey Explorer (WISE) catalog

Science.gov (United States)

Nguyen, T.; Pankratius, V.; Eckman, L.; Seager, S.

2018-04-01

Debris disks around stars other than the Sun have received significant attention in studies of exoplanets, specifically exoplanetary system formation. Since debris disks are major sources of infrared emissions, infrared survey data such as the Wide-Field Infrared Survey (WISE) catalog potentially harbors numerous debris disk candidates. However, it is currently challenging to perform disk candidate searches for over 747 million sources in the WISE catalog due to the high probability of false positives caused by interstellar matter, galaxies, and other background artifacts. Crowdsourcing techniques have thus started to harness citizen scientists for debris disk identification since humans can be easily trained to distinguish between desired artifacts and irrelevant noises. With a limited number of citizen scientists, however, increasing data volumes from large surveys will inevitably lead to analysis bottlenecks. To overcome this scalability problem and push the current limits of automated debris disk candidate identification, we present a novel approach that uses citizen science results as a seed to train machine learning based classification. In this paper, we detail a case study with a computer-aided discovery pipeline demonstrating such feasibility based on WISE catalog data and NASA's Disk Detective project. Our approach of debris disk candidates classification was shown to be robust under a wide range of image quality and features. Our hybrid approach of citizen science with algorithmic scalability can facilitate big data processing for future detections as envisioned in future missions such as the Transiting Exoplanet Survey Satellite (TESS) and the Wide-Field Infrared Survey Telescope (WFIRST).

SCIENTIFIC EFFICIENCY OF GROUND-BASED TELESCOPES

International Nuclear Information System (INIS)

Abt, Helmut A.

2012-01-01

I scanned the six major astronomical journals of 2008 for all 1589 papers that are based on new data obtained from ground-based optical/IR telescopes worldwide. Then I collected data on numbers of papers, citations to them in 3+ years, the most-cited papers, and annual operating costs. These data are assigned to four groups by telescope aperture. For instance, while the papers from telescopes with an aperture >7 m average 1.29 more citations than those with an aperture of 2 to 7 m) telescopes. I wonder why the large telescopes do so relatively poorly and suggest possible reasons. I also found that papers based on archival data, such as the Sloan Digital Sky Survey, produce 10.6% as many papers and 20.6% as many citations as those based on new data. Also, the 577.2 papers based on radio data produced 36.3% as many papers and 33.6% as many citations as the 1589 papers based on optical/IR telescopes.

Parametric cost models for space telescopes

Science.gov (United States)

Stahl, H. Philip; Henrichs, Todd; Dollinger, Courtnay

2017-11-01

Multivariable parametric cost models for space telescopes provide several benefits to designers and space system project managers. They identify major architectural cost drivers and allow high-level design trades. They enable cost-benefit analysis for technology development investment. And, they provide a basis for estimating total project cost. A survey of historical models found that there is no definitive space telescope cost model. In fact, published models vary greatly [1]. Thus, there is a need for parametric space telescopes cost models. An effort is underway to develop single variable [2] and multi-variable [3] parametric space telescope cost models based on the latest available data and applying rigorous analytical techniques. Specific cost estimating relationships (CERs) have been developed which show that aperture diameter is the primary cost driver for large space telescopes; technology development as a function of time reduces cost at the rate of 50% per 17 years; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and increasing mass reduces cost.

Parametric Cost Models for Space Telescopes

Science.gov (United States)

Stahl, H. Philip; Henrichs, Todd; Dollinger, Courtney

2010-01-01

Multivariable parametric cost models for space telescopes provide several benefits to designers and space system project managers. They identify major architectural cost drivers and allow high-level design trades. They enable cost-benefit analysis for technology development investment. And, they provide a basis for estimating total project cost. A survey of historical models found that there is no definitive space telescope cost model. In fact, published models vary greatly [1]. Thus, there is a need for parametric space telescopes cost models. An effort is underway to develop single variable [2] and multi-variable [3] parametric space telescope cost models based on the latest available data and applying rigorous analytical techniques. Specific cost estimating relationships (CERs) have been developed which show that aperture diameter is the primary cost driver for large space telescopes; technology development as a function of time reduces cost at the rate of 50% per 17 years; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and increasing mass reduces cost.

Closing the contrast gap between testbed and model prediction with WFIRST-CGI shaped pupil coronagraph

Science.gov (United States)

Zhou, Hanying; Nemati, Bijan; Krist, John; Cady, Eric; Prada, Camilo M.; Kern, Brian; Poberezhskiy, Ilya

2016-07-01

JPL has recently passed an important milestone in its technology development for a proposed NASA WFIRST mission coronagraph: demonstration of better than 1x10-8 contrast over broad bandwidth (10%) on both shaped pupil coronagraph (SPC) and hybrid Lyot coronagraph (HLC) testbeds with the WFIRST obscuration pattern. Challenges remain, however, in the technology readiness for the proposed mission. One is the discrepancies between the achieved contrasts on the testbeds and their corresponding model predictions. A series of testbed diagnoses and modeling activities were planned and carried out on the SPC testbed in order to close the gap. A very useful tool we developed was a derived "measured" testbed wavefront control Jacobian matrix that could be compared with the model-predicted "control" version that was used to generate the high contrast dark hole region in the image plane. The difference between these two is an estimate of the error in the control Jacobian. When the control matrix, which includes both amplitude and phase, was modified to reproduce the error, the simulated performance closely matched the SPC testbed behavior in both contrast floor and contrast convergence speed. This is a step closer toward model validation for high contrast coronagraphs. Further Jacobian analysis and modeling provided clues to the possible sources for the mismatch: DM misregistration and testbed optical wavefront error (WFE) and the deformable mirror (DM) setting for correcting this WFE. These analyses suggested that a high contrast coronagraph has a tight tolerance in the accuracy of its control Jacobian. Modifications to both testbed control model as well as prediction model are being implemented, and future works are discussed.

Extending Supernova Spectral Templates for Next Generation Space Telescope Observations

Science.gov (United States)

Roberts-Pierel, Justin; Rodney, Steven A.; Steven Rodney

2018-01-01

Widely used empirical supernova (SN) Spectral Energy Distributions (SEDs) have not historically extended meaningfully into the ultraviolet (UV), or the infrared (IR). However, both are critical for current and future aspects of SN research including UV spectra as probes of poorly understood SN Ia physical properties, and expanding our view of the universe with high-redshift James Webb Space Telescope (JWST) IR observations. We therefore present a comprehensive set of SN SED templates that have been extended into the UV and IR, as well as an open-source software package written in Python that enables a user to generate their own extrapolated SEDs. We have taken a sampling of core-collapse (CC) and Type Ia SNe to get a time-dependent distribution of UV and IR colors (U-B,r’-[JHK]), and then generated color curves are used to extrapolate SEDs into the UV and IR. The SED extrapolation process is now easily duplicated using a user’s own data and parameters via our open-source Python package: SNSEDextend. This work develops the tools necessary to explore the JWST’s ability to discriminate between CC and Type Ia SNe, as well as provides a repository of SN SEDs that will be invaluable to future JWST and WFIRST SN studies.

The IFS for WFIRST CGI: Science Requirements to Design

Science.gov (United States)

Groff, Tyler; Gong, Qian; Mandell, Avi M.; Zimmerman, Neil; Rizzo, Maxime; McElwain, Michael; harvey, david; Saxena, Prabal; cady, eric; mejia prada, camilo

2018-01-01

Direct Imaging of exoplanets using a coronagraph has become a major field of research both on the ground and in space. Key to the science of direct imaging is the spectroscopic capabilities of the instrument, our ability to extract spectra, and measure the abundance of molecular species such as Methane. To take these spectra, the WFIRST coronagraph instrument (CGI) uses an integral field spectrograph (IFS), which encodes the spectrum into a two-dimensional image on the detector. This results in more efficient detection and characterization of targets, and the spectral information is critical to achieving detection limits below the speckle floor of the imager. The CGI IFS operates in three 18% bands spanning 600nm to 970nm at a nominal spectral resolution of R50. We present the current science and engineering requirements for the IFS design, the instrument design, anticipated performance, and how the calibration is integrated into the focal plane wavefront control algorithms. We also highlight the role of the Prototype Imaging Spectrograph for Coronagraphic Exoplanet Studies (PISCES) at the JPL High Contrast Imaging Testbed to demonstrate performance and validate calibration methodologies for the flight instrument.

Origins Space Telescope

Science.gov (United States)

Cooray, Asantha; Origins Space Telescope Study Team

2018-01-01

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, our completed first mission concept and an introduction to the second concept that will be studied at the study center in 2018. This presentation will also summarize key science drivers and the key study milestones between 2018 and 2020.

3D-HST: A WIDE-FIELD GRISM SPECTROSCOPIC SURVEY WITH THE HUBBLE SPACE TELESCOPE

International Nuclear Information System (INIS)

Brammer, Gabriel B.; Van Dokkum, Pieter G.; Skelton, Rosalind E.; Nelson, Erica; Bezanson, Rachel; Leja, Joel; Lundgren, Britt; Franx, Marijn; Fumagalli, Mattia; Patel, Shannon; Labbé, Ivo; Rix, Hans-Walter; Schmidt, Kasper B.; Da Cunha, Elisabete; Kriek, Mariska; Erb, Dawn K.; Fan, Xiaohui; Förster Schreiber, Natascha; Illingworth, Garth D.; Magee, Dan

2012-01-01

We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the physical processes that shape galaxies in the distant universe. 3D-HST provides rest-frame optical spectra for a sample of ∼7000 galaxies at 1 2 ) of the CANDELS Treasury survey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L grism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of ∼5 per resolution element at H 140 ∼ 23.1 and a 5σ emission-line sensitivity of ∼5 × 10 –17 erg s –1 cm –2 for typical objects, improving by a factor of ∼2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide continuous wavelength coverage from 1.1 to 1.6 μm at a spatial resolution of ∼0.''13, which, combined with their depth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary reduction and analysis of the grism observations, including emission-line and redshift measurements from combined fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis yields redshift estimates with a precision of σ(z) = 0.0034(1 + z), or σ(v) ≈ 1000 km s –1 . We illustrate how the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types of objects, including a quasar at z = 4.7, quiescent galaxies at z ∼ 2, and the most distant T-type brown dwarf star known. The combination of the CANDELS and 3D-HST surveys will provide the definitive imaging and spectroscopic data set for studies of the 1 < z < 3.5 universe until the launch of the James Webb Space Telescope.

Near-Earth Object Orbit Linking with the Large Synoptic Survey Telescope

Science.gov (United States)

Vereš, Peter; Chesley, Steven R.

2017-07-01

We have conducted a detailed simulation of the ability of the Large Synoptic Survey Telescope (LSST) to link near-Earth and main belt asteroid detections into orbits. The key elements of the study were a high-fidelity detection model and the presence of false detections in the form of both statistical noise and difference image artifacts. We employed the Moving Object Processing System (MOPS) to generate tracklets, tracks, and orbits with a realistic detection density for one month of the LSST survey. The main goals of the study were to understand whether (a) the linking of near-Earth objects (NEOs) into orbits can succeed in a realistic survey, (b) the number of false tracks and orbits will be manageable, and (c) the accuracy of linked orbits would be sufficient for automated processing of discoveries and attributions. We found that the overall density of asteroids was more than 5000 per LSST field near opposition on the ecliptic, plus up to 3000 false detections per field in good seeing. We achieved 93.6% NEO linking efficiency for H< 22 on tracks composed of tracklets from at least three distinct nights within a 12 day interval. The derived NEO catalog was comprised of 96% correct linkages. Less than 0.1% of orbits included false detections, and the remainder of false linkages stemmed from main belt confusion, which was an artifact of the short time span of the simulation. The MOPS linking efficiency can be improved by refined attribution of detections to known objects and by improved tuning of the internal kd-tree linking algorithms.

Variability Properties of Four Million Sources in the TESS Input Catalog Observed with the Kilodegree Extremely Little Telescope Survey

Science.gov (United States)

Oelkers, Ryan J.; Rodriguez, Joseph E.; Stassun, Keivan G.; Pepper, Joshua; Somers, Garrett; Kafka, Stella; Stevens, Daniel J.; Beatty, Thomas G.; Siverd, Robert J.; Lund, Michael B.; Kuhn, Rudolf B.; James, David; Gaudi, B. Scott

2018-01-01

The Kilodegree Extremely Little Telescope (KELT) has been surveying more than 70% of the celestial sphere for nearly a decade. While the primary science goal of the survey is the discovery of transiting, large-radii planets around bright host stars, the survey has collected more than 106 images, with a typical cadence between 10–30 minutes, for more than four million sources with apparent visual magnitudes in the approximate range 7TESS Input catalog and the AAVSO Variable Star Index to precipitate the follow-up and classification of each source. The catalog is maintained as a living database on the Filtergraph visualization portal at the URL https://filtergraph.com/kelt_vars.

A decade of cost-reduction in very large telescopes - The SST as prototype of special-purpose telescopes

Science.gov (United States)

Smith, Harlan J.

1989-10-01

Many design and technical innovations over the past ten or fifteen years have reduced the costs of very large telescopes by nearly an order of magnitude over those of classical designs. Still a further order of magnitude reduction is possible if the telescope is specialized for on-axis spectroscopy, giving up especially the luxuries of wide field, multiple focal positions, and access to all the sky at will. The SST (Spectroscopic Survey Telescope) will use eighty-five 1-m circular mirrors mounted in a steel frame composed of hundreds of interlocking tetrahedrons, keeping a fixed elevation angle of 60 deg with rotation only in azimuth. Using an optical fiber it will feed as much light to spectrographs as can be done by a conventional 8-m telescope, yet has a target basic completion cost of only $6 million.

Augmenting the Funding Sources for Space Science and the ASTRO-1 Space Telescope

Science.gov (United States)

Morse, Jon

2015-08-01

The BoldlyGo Institute was formed in 2013 to augment the planned space science portfolio through philanthropically funded robotic space missions, similar to how some U.S. medical institutes and ground-based telescopes are funded. I introduce BoldlyGo's two current projects: the SCIM mission to Mars and the ASTRO-1 space telescope. In particular, ASTRO-1 is a 1.8-meter off-axis (unobscured) ultraviolet-visible space observatory to be located in a Lagrange point or heliocentric orbit with a wide-field panchromatic camera, medium- and high-resolution spectrograph, and high-contrast imaging coronagraph and/or an accompanying starshade/occulter. It is intended for the post-Hubble Space Telescope era in the 2020s, enabling unique measurements of a broad range of celestial targets, while providing vital complementary capabilities to other ground- and space-based facilities such as the JWST, ALMA, WFIRST-AFTA, LSST, TESS, Euclid, and PLATO. The ASTRO-1 architecture simultaneously wields great scientific power while being technically viable and affordable. A wide variety of scientific programs can be accomplished, addressing topics across space astronomy, astrophysics, fundamental physics, and solar system science, as well as being technologically informative to future large-aperture programs. ASTRO-1 is intended to be a new-generation research facility serving a broad national and international community, as well as a vessel for impactful public engagement. Traditional institutional partnerships and consortia, such as are common with private ground-based observatories, may play a role in the support and governance of ASTRO-1; we are currently engaging interested international organizations. In addition to our planned open guest observer program and accessible data archive, we intend to provide a mechanism whereby individual scientists can buy in to a fraction of the gauranteed observing time. Our next step in ASTRO-1 development is to form the ASTRO-1 Requirements Team

GESE: A Small UV Space Telescope to Conduct a Large Spectroscopic Survey of Z-1 Galaxies

Science.gov (United States)

Heap, Sara R.; Gong, Qian; Hull, Tony; Kruk, Jeffrey; Purves, Lloyd

2013-01-01

One of the key goals of NASA's astrophysics program is to answer the question: How did galaxies evolve into the spirals and elliptical galaxies that we see today? We describe a space mission concept called Galaxy Evolution Spectroscopic Explorer (GESE) to address this question by making a large spectroscopic survey of galaxies at a redshift, z is approximately 1 (look-back time of approximately 8 billion years). GESE is a 1.5-meter space telescope with an ultraviolet (UV) multi-object slit spectrograph that can obtain spectra of hundreds of galaxies per exposure. The spectrograph covers the spectral range, 0.2-0.4 micrometers at a spectral resolving power, R approximately 500. This observed spectral range corresponds to 0.1-0.2 micrometers as emitted by a galaxy at a redshift, z=1. The mission concept takes advantage of two new technological advances: (1) light-weighted, wide-field telescope mirrors, and (2) the Next- Generation MicroShutter Array (NG-MSA) to be used as a slit generator in the multi-object slit spectrograph.

Habitable Exoplanet Imager Optical Telescope Concept Design

Science.gov (United States)

Stahl, H Philip

2017-01-01

The Habitable Exoplanet Imaging Mission (HabEx) is one of four missions under study for the 2020 Astrophysics Decadal Survey. Its goal is to directly image and spectroscopically characterize planetary systems in the habitable zone of Sun-like stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by 100 to 2500 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving the HabEx science goals is a large, ultra-stable UV/Optical/Near-IR (UVOIR) telescope. The baseline HabEx telescope is a 4-meter off-axis unobscured three-mirror-anastigmatic, diffraction limited at 400 nm with wavefront stability on the order of a few 10s of picometers. This paper summarizes the opto-mechanical design of the HabEx baseline optical telescope assembly, including a discussion of how science requirements drive the telescope's specifications, and presents analysis that the baseline telescope structure meets its specified tolerances.

Habitable exoplanet imager optical telescope concept design

Science.gov (United States)

Stahl, H. Philip

2017-09-01

The Habitable Exoplanet Imaging Mission (HabEx) is one of four missions under study for the 2020 Astrophysics Decadal Survey. Its goal is to directly image and spectroscopically characterize planetary systems in the habitable zone of Sunlike stars. Additionally, HabEx will perform a broad range of general astrophysics science enabled by 100 to 2500 nm spectral range and 3 x 3 arc-minute FOV. Critical to achieving the HabEx science goals is a large, ultra-stable UV/Optical/Near-IR (UVOIR) telescope. The baseline HabEx telescope is a 4-meter off-axis unobscured three-mirroranastigmatic, diffraction limited at 400 nm with wavefront stability on the order of a few 10s of picometers. This paper summarizes the opto-mechanical design of the HabEx baseline optical telescope assembly, including a discussion of how science requirements drive the telescope's specifications, and presents analysis that the baseline telescope structure meets its specified tolerances.

THE ALLEN TELESCOPE ARRAY Pi GHz SKY SURVEY. I. SURVEY DESCRIPTION AND STATIC CATALOG RESULTS FOR THE BOOeTES FIELD

International Nuclear Information System (INIS)

Bower, Geoffrey C.; Croft, Steve; Keating, Garrett; Whysong, David; Backer, Don; Bauermeister, Amber; Blitz, Leo; Bock, Douglas; Cheng, Calvin; Dexter, Matt; Engargiola, Greg; Ackermann, Rob; Atkinson, Shannon; Backus, Peter; Bradford, Tucker; Davis, Mike; Dreher, John; Barott, Billy; Cork, Chris; DeBoer, Dave

2010-01-01

The Pi GHz Sky Survey (PiGSS) is a key project of the Allen Telescope Array. PiGSS is a 3.1 GHz survey of radio continuum emission in the extragalactic sky with an emphasis on synoptic observations that measure the static and time-variable properties of the sky. During the 2.5 year campaign, PiGSS will twice observe ∼250,000 radio sources in the 10,000 deg 2 region of the sky with b>30 0 to an rms sensitivity of ∼1 mJy. Additionally, sub-regions of the sky will be observed multiple times to characterize variability on timescales of days to years. We present here observations of a 10 deg 2 region in the Booetes constellation overlapping the NOAO Deep Wide Field Survey field. The PiGSS image was constructed from 75 daily observations distributed over a 4 month period and has an rms flux density between 200 and 250 μJy. This represents a deeper image by a factor of 4-8 than we will achieve over the entire 10,000 deg 2 . We provide flux densities, source sizes, and spectral indices for the 425 sources detected in the image. We identify ∼100 new flat-spectrum radio sources; we project that when completed PiGSS will identify 10 4 flat-spectrum sources. We identify one source that is a possible transient radio source. This survey provides new limits on faint radio transients and variables with characteristic durations of months.

EFFECT OF MEASUREMENT ERRORS ON PREDICTED COSMOLOGICAL CONSTRAINTS FROM SHEAR PEAK STATISTICS WITH LARGE SYNOPTIC SURVEY TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Bard, D.; Chang, C.; Kahn, S. M.; Gilmore, K.; Marshall, S. [KIPAC, Stanford University, 452 Lomita Mall, Stanford, CA 94309 (United States); Kratochvil, J. M.; Huffenberger, K. M. [Department of Physics, University of Miami, Coral Gables, FL 33124 (United States); May, M. [Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); AlSayyad, Y.; Connolly, A.; Gibson, R. R.; Jones, L.; Krughoff, S. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Ahmad, Z.; Bankert, J.; Grace, E.; Hannel, M.; Lorenz, S. [Department of Physics, Purdue University, West Lafayette, IN 47907 (United States); Haiman, Z.; Jernigan, J. G., E-mail: djbard@slac.stanford.edu [Department of Astronomy and Astrophysics, Columbia University, New York, NY 10027 (United States); and others

2013-09-01

We study the effect of galaxy shape measurement errors on predicted cosmological constraints from the statistics of shear peak counts with the Large Synoptic Survey Telescope (LSST). We use the LSST Image Simulator in combination with cosmological N-body simulations to model realistic shear maps for different cosmological models. We include both galaxy shape noise and, for the first time, measurement errors on galaxy shapes. We find that the measurement errors considered have relatively little impact on the constraining power of shear peak counts for LSST.

DESTINY, The Dark Energy Space Telescope

Science.gov (United States)

Pasquale, Bert A.; Woodruff, Robert A.; Benford, Dominic J.; Lauer, Tod

2007-01-01

We have proposed the development of a low-cost space telescope, Destiny, as a concept for the NASA/DOE Joint Dark Energy Mission. Destiny is a 1.65m space telescope, featuring a near-infrared (0.85-1.7m) survey camera/spectrometer with a moderate flat-field field of view (FOV). Destiny will probe the properties of dark energy by obtaining a Hubble diagram based on Type Ia supernovae and a large-scale mass power spectrum derived from weak lensing distortions of field galaxies as a function of redshift.

Laboratory Measurement of the Brighter-fatter Effect in an H2RG Infrared Detector

Science.gov (United States)

Plazas, A. A.; Shapiro, C.; Smith, R.; Huff, E.; Rhodes, J.

2018-06-01

The “brighter-fatter” (BF) effect is a phenomenon—originally discovered in charge coupled devices—in which the size of the detector point-spread function (PSF) increases with brightness. We present, for the first time, laboratory measurements demonstrating the existence of the effect in a Hawaii-2RG HgCdTe near-infrared (NIR) detector. We use JPL’s Precision Projector Laboratory, a facility for emulating astronomical observations with UV/VIS/NIR detectors, to project about 17,000 point sources onto the detector to stimulate the effect. After calibrating the detector for nonlinearity with flat-fields, we find evidence that charge is nonlinearly shifted from bright pixels to neighboring pixels during exposures of point sources, consistent with the existence of a BF-type effect. NASAs Wide Field Infrared Survey Telescope (WFIRST) will use similar detectors to measure weak gravitational lensing from the shapes of hundreds of million of galaxies in the NIR. The WFIRST PSF size must be calibrated to ≈0.1% to avoid biased inferences of dark matter and dark energy parameters; therefore further study and calibration of the BF effect in realistic images will be crucial.

Sunyaev-Zeldovich Predictions for the Atacama Cosmology Telescope

Science.gov (United States)

Menanteau, Felipe; Hughes, J. P.; Jimenez, R.; Barkhouse, W.; Berta, Z.; Hansen, S.; Hernandez-Monteagudo, C.; Kosowsky, A.; Lin, Y. T.; Moodley, K.; Ngeow, C.; Roche, N.; Spergel, D.; Tucker, D.; Verde, L.

2007-05-01

We present predictions for the microwave sky in a low-extinction region centered near RA = 23:00 and Dec = -55:12, which will be surveyed in the coming year at 145 GHz by the Atacama Cosmology Telescope (ACT, PI: Lyman Page) and in the X-ray band by XMM-Newton (PI: Hans Boehringer). The predictions are based on Sunyaev-Zeldovich distortions drawn from optical data collected by the Blanco Cosmology Survey (BCS). We also compare the predictions with X-ray data from the ROSAT All Sky Survey. The BCS (PI: Joe Mohr) is a NOAO large, wide-field survey project that has been awarded 45 nights on the CTIO Blanco 4-meter telescope to image two 50 square-degree patches of the southern sky in four bands (griz). The survey began in 2005 and has completed two (out of three) years of data taking. A preliminary automated image reduction and analysis pipeline for the BCS data is briefly summarized. Financial support was provided by the NSF under the PIRE program (OISE-0530095).

GESE: a small UV space telescope to conduct a large spectroscopic survey of z˜1 Galaxies

Science.gov (United States)

Heap, Sara R.; Gong, Qian; Hull, Tony; Kruk, Jeffrey; Purves, Lloyd

2014-11-01

One of the key goals of NASA's astrophysics program is to answer the question: How did galaxies evolve into the spirals and elliptical galaxies that we see today? We describe a space mission concept called Galaxy Evolution Spectroscopic Explorer (GESE) to address this question by making a large spectroscopic survey of galaxies at a redshift, z˜1 (look-back time of ˜8 billion years). GESE is a 1.5-m space telescope with an ultraviolet (UV) multi-object slit spectrograph that can obtain spectra of hundreds of galaxies per exposure. The spectrograph covers the spectral range, 0.2-0.4 μm at a spectral resolving power, R˜500. This observed spectral range corresponds to 0.1-0.2 μm as emitted by a galaxy at a redshift, z=1. The mission concept takes advantage of two new technological advances: (1) light-weighted, wide-field telescope mirrors, and (2) the Next-Generation MicroShutter Array (NG-MSA) to be used as a slit generator in the multi-object slit spectrograph.

Science with Synthetic Stellar Surveys

Science.gov (United States)

Sanderson, Robyn Ellyn

2018-04-01

A new generation of observational projects is poised to revolutionize our understanding of the resolved stellar populations of Milky-Way-like galaxies at an unprecedented level of detail, ushering in an era of precision studies of galaxy formation. In the Milky Way itself, astrometric, spectroscopic and photometric surveys will measure three-dimensional positions and velocities and numerous chemical abundances for stars from the disk to the halo, as well as for many satellite dwarf galaxies. In the Local Group and beyond, HST, JWST and eventually WFIRST will deliver pristine views of resolved stars. The groundbreaking scale and dimensionality of this new view of resolved stellar populations in galaxies challenge us to develop new theoretical tools to robustly compare these surveys to simulated galaxies, in order to take full advantage of our new ability to make detailed predictions for stellar populations within a cosmological context. I will describe a framework for generating realistic synthetic star catalogs and mock surveys from state-of-the-art cosmological-hydrodynamical simulations, and present several early scientific results from, and predictions for, resolved stellar surveys of our Galaxy and its neighbors.

Characterizing Earth Analogs in Reflected Light: Atmospheric Retrieval Studies for Future Space Telescopes

Science.gov (United States)

Feng, Y. Katherina; Robinson, Tyler D.; Fortney, Jonathan J.; Lupu, Roxana E.; Marley, Mark S.; Lewis, Nikole K.; Macintosh, Bruce; Line, Michael R.

2018-05-01

Space-based high-contrast imaging mission concepts for studying rocky exoplanets in reflected light are currently under community study. We develop an inverse modeling framework to estimate the science return of such missions given different instrument design considerations. By combining an exoplanet albedo model, instrument noise model, and ensemble Markov chain Monte Carlo sampler, we explore retrievals of atmospheric and planetary properties for Earth twins as a function of signal-to-noise ratio (S/N) and resolution (R). Our forward model includes Rayleigh-scattering, single-layer water clouds with patchy coverage, and pressure-dependent absorption due to water vapor, oxygen, and ozone. We simulate data at R = 70 and 140 from 0.4 to 1.0 μm with S/N = 5, 10, 15, and 20 at 550 nm (i.e., for HabEx/LUVOIR-type instruments). At these same S/Ns, we simulate data for WFIRST paired with a starshade, which includes two photometric points between 0.48 and 0.6 μm and R = 50 spectroscopy from 0.6 to 0.97 μm. Given our noise model for WFIRST-type detectors, we find that weak detections of water vapor, ozone, and oxygen can be achieved with observations with at least R = 70/S/N = 15 or R = 140/S/N = 10 for improved detections. Meaningful constraints are only achieved with R = 140/S/N = 20 data. The WFIRST data offer limited diagnostic information, needing at least S/N = 20 to weakly detect gases. Most scenarios place limits on planetary radius but cannot constrain surface gravity and, thus, planetary mass.

THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS. VIII. PRELIMINARY PUBLIC CATALOG RELEASE

Energy Technology Data Exchange (ETDEWEB)

Soto, M.; Bellini, A.; Anderson, J.; Van der Marel, R. P.; Brown, T. M. [Space Telescope Science Institute, San Martin Drive 3700, Baltimore, MD 21218 (United States); Piotto, G.; Granata, V.; Ortolani, S.; Nardiello, D. [Dipartimento di Fisica e Astronomia Galileo Galilei, Università di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova (Italy); Bedin, L. R. [INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Milone, A. P. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT, 2611 (Australia); Cool, A. M. [Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132 (United States); King, I. R. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Sarajedini, A. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Cassisi, S. [Osservatorio Astronomico di Teramo, Via Mentore Maggini s.n.c., I-64100 Teramo (Italy); Aparicio, A.; Hidalgo, S., E-mail: mario.soto@uda.cl [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Canary Islands (Spain)

2017-01-01

The Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular Clusters (GO-13297) has been specifically designed to complement the existing F606W and F814W observations of the Advanced Camera for Surveys (ACS) Globular Cluster Survey (GO-10775) by observing the most accessible 47 of the previous survey’s 65 clusters in three WFC3/UVIS filters F275W, F336W, and F438W. The new survey also adds super-solar metallicity open cluster NGC 6791 to increase the metallicity diversity. The combined survey provides a homogeneous 5-band data set that can be used to pursue a broad range of scientific investigations. In particular, the chosen UV filters allow the identification of multiple stellar populations by targeting the regions of the spectrum that are sensitive to abundance variations in C, N, and O. In order to provide the community with uniform preliminary catalogs, we have devised an automated procedure that performs high-quality photometry on the new UV observations (along with similar observations of seven other programs in the archive). This procedure finds and measures the potential sources on each individual exposure using library point-spread functions and cross-correlates these observations with the original ACS-Survey catalog. The catalog of 57 clusters we publish here will be useful to identify stars in the different stellar populations, in particular for spectroscopic follow-up. Eventually, we will construct a more sophisticated catalog and artificial-star tests based on an optimal reduction of the UV survey data, but the catalogs presented here give the community the chance to make early use of this HST Treasury survey.

WILL THE LARGE SYNOPTIC SURVEY TELESCOPE DETECT EXTRA-SOLAR PLANETESIMALS ENTERING THE SOLAR SYSTEM?

International Nuclear Information System (INIS)

Moro-Martin, Amaya; Turner, Edwin L.; Loeb, Abraham

2009-01-01

Planetesimal formation is a common by-product of the star formation process. Taking the dynamical history of the solar system as a guideline-in which the planetesimal belts were heavily depleted due to gravitational perturbation with the giant planets-and assuming similar processes have taken place in other planetary systems, one would expect the interstellar space to be filled with extra-solar planetesimals. However, not a single one of these objects has been detected so far entering the solar system, even though it would clearly be distinguishable from a solar system comet due to its highly hyperbolic orbit. The Large Synoptic Survey Telescope (LSST) will provide wide coverage maps of the sky to a very high sensitivity, ideal to detect moving objects like comets, both active and inactive. In anticipation of these observations, we estimate how many inactive 'interstellar comets' might be detected during the duration of the survey. The calculation takes into account estimates (from observations and models) of the number density of stars, the amount of solids available to form planetesimals, the frequency of planet and planetesimal formation, the efficiency of planetesimal ejection, and the possible size distribution of these small bodies.

Optical Design of the STAR-X Telescope

Science.gov (United States)

Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

2017-01-01

Top-level science goals of the Survey and Time-domain Astrophysical Research eXplorer (STAR-X) include: investigations of most violent explosions in the universe, study of growth of black holes across cosmic time and mass scale, and measure how structure formation heats majority of baryons in the universe. To meet these goals, the field-of-view of the telescope should be about 1 square-degree, the angular resolution should be 5 arc-seconds or below across large part of the field-of-view. The on-axis effective area at 1 KeV should be about 2,000 sq cm. Payload cost and launch considerations limit the outer diameter, focal length, and mass to 1.3 meters, 5 meters, and 250 kilograms, respectively. Telescope design is based on a segmented meta-shell approach we have developed at Goddard Space Flight Center for the STAR-X telescope. The telescope shells are divided into 30-degree segments. Individual telescopes and meta-shells are nested inside each other to meet the effective area requirements in 0.5 - 6.0 KeV range. We consider Wolter-Schwarzschild, and Modified-Wolter-Schwarzschild telescope designs as basic building blocks of the nested STAR-X telescope. These designs offer an excellent resolution over a large field of views. Nested telescopes are vulnerable to stray light problems. We have designed a multi-component baffle system to eliminate direct and single-reflection light paths inside the telescopes. Large number of internal and external baffle vane structures are required to prevent stray rays from reaching the focal plane. We have developed a simple ray-trace based tool to determine the dimensions and locations of the baffles. In this paper, we present the results of our trade studies, baffle design studies, and optical performance analyses of the STAR-X telescope.

Fast Fourier transform telescope

International Nuclear Information System (INIS)

Tegmark, Max; Zaldarriaga, Matias

2009-01-01

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 2 N rather than N 2 ) 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.

Liverpool Telescope 2: beginning the design phase

Science.gov (United States)

Copperwheat, Christopher M.; Steele, Iain A.; Barnsley, Robert M.; Bates, Stuart D.; Bode, Mike F.; Clay, Neil R.; Collins, Chris A.; Jermak, Helen E.; Knapen, Johan H.; Marchant, Jon M.; Mottram, Chris J.; Piascik, Andrzej S.; Smith, Robert J.

2016-07-01

The Liverpool Telescope is a fully robotic 2-metre telescope located at the Observatorio del Roque de los Muchachos on the Canary Island of La Palma. The telescope began routine science operations in 2004, and currently seven simultaneously mounted instruments support a broad science programme, with a focus on transient followup and other time domain topics well suited to the characteristics of robotic observing. Work has begun on a successor facility with the working title `Liverpool Telescope 2'. We are entering a new era of time domain astronomy with new discovery facilities across the electromagnetic spectrum, and the next generation of optical survey facilities such as LSST are set to revolutionise the field of transient science in particular. The fully robotic Liverpool Telescope 2 will have a 4-metre aperture and an improved response time, and will be designed to meet the challenges of this new era. Following a conceptual design phase, we are about to begin the detailed design which will lead towards the start of construction in 2018, for first light ˜2022. In this paper we provide an overview of the facility and an update on progress.

Discovery of KPS-1b, a Transiting Hot-Jupiter, with an Amateur Telescope Setup (Abstract)

Science.gov (United States)

Benni, P.; Burdanov, A.; Krushinsky, V.; Sokov, E.

2018-06-01

(Abstract only) Using readily available amateur equipment, a wide-field telescope (Celestron RASA, 279 mm f/2.2) coupled with a SBIG ST-8300M camera was set up at a private residence in a fairly light polluted suburban town thirty miles outside of Boston, Massachusetts. This telescope participated in the Kourovka Planet Search (KPS) prototype survey, along with a MASTER-II Ural wide field telescope near Yekaterinburg, Russia. One goal was to determine if higher resolution imaging ( 2 arcsec/pixel) with much lower sky coverage can practically detect exoplanet transits compared to the successful very wide-field exoplanet surveys (KELT, XO, WASP, HATnet, TrES, Qatar, etc.) which used an array of small aperture telescopes coupled to CCDs.

LOBSTER: new space x-ray telescopes

Science.gov (United States)

Hudec, R.; Sveda, L.; Pína, L.; Inneman, A.; Semencova, V.; Skulinova, M.

2017-11-01

The LOBSTER telescopes are based on the optical arrangement of the lobster eye. The main difference from classical X-ray space telescopes in wide use is the very large field of view while the use of optics results in higher efficiency if compared with detectors without optics. Recent innovative technologies have enabled to design, to develop and to test first prototypes. They will provide deep sensitive survey of the sky in X-rays for the first time which is essential for both long-term monitoring of celestial high-energy sources as well as in understanding transient phenomena. The technology is now ready for applications in space.

ATLAS Probe: Exploring Frontiers in Galaxy Evolution, Cosmology, and Milky Way Science

Science.gov (United States)

Wang, Yun; Robberto, Massimo; Dickinson, Mark; Ferguson, Henry C.; Hillenbrand, Lynne; Hirata, Christopher M.; Cimatti, Andrea; Bartlett, James; Barkhouser, Robert; Benjamin, Robert A.; Brinchmann, Jarle; Chary, Ranga-Ram; Conroy, Charlie; Daddi, Emanuele; Donahue, Megan; Dore, Olivier; Eisenhardt, Peter; Fraser, Wesley C.; Helou, George; Kirkpatrick, J. Davy; Malhotra, Sangeeta; Moscardini, Lauro; Ninkov, Zoran; Ressler, Michael; Rhoads, James; Rhodes, Jason; Shapley, Alice; Smee, Stephen; ATLAS Probe Team

2018-01-01

ATLAS (Astrophysics Telescope for Large Area Spectroscopy) Probe is a concept for a NASA probe-class space mission that leverages WFIRST imaging for targeted spectroscopy. ATLAS Probe will obtain spectra of 90% of all galaxies imaged by the WFIRST High Latitude Survey at z > 0.5, with slit spectra of 300 million galaxies to z = 7. ATLAS Probe and WFIRST together will produce a 3D map of the Universe with Mpc resolution over 2200 sq deg, the definitive data sets for studying galaxy evolution, probing dark matter, dark energy and modification of general relativity, and quantifying the 3D structure and stellar content of the Milky Way.ATLAS Probe science spans four broad categories: (1) Revolutionize galaxy evolution studies by tracing the relation between galaxies and dark matter from the local group to cosmic voids and filaments, from the epoch of reionization through the peak era of galaxy assembly. (2) Open a new window into the Universe by mapping the dark matter filaments using 3D weak lensing with spectroscopic redshifts to unveil the nature of the dark Universe, and obtaining definitive measurements of dark energy and possible modification of general relativity using cosmic large-scale structure. (3) Probe the Milky Way's dust-shrouded regions, reaching the far side of our Galaxy. (4) Characterize asteroids and comets in the outer Solar System.ATLAS Probe is a 1.5m telescope with a field of view (FoV) of 0.4 sq deg, and uses Digital Micromirror Devices (DMDs) as slit selectors. It has a spectroscopic resolution of R = 600, and a wavelength range of 1-4μm. The lack of slit spectroscopy from space over a wide FoV is the obvious gap in current and planned future space missions; ATLAS fills this big gap with an unprecedented spectroscopic capability (with an estimated spectroscopic multiplex factor of 5000-10000). It has an estimated cost under $1B, with a single instrument, a telescope aperture that allows for a lighter launch vehicle, and mature technology

Beyond JWST: Science Drivers for the Next Great UVOIR Space Telescope

Science.gov (United States)

Tumlinson, Jason; Seager, Sara; Dalcanton, Julianne; Postman, Marc; Aigrain, Suzanne; battel, Steven; Brandt, W. Niel; Conroy, Charlie; Feinberg, Lee; Gezari, Suvi; Guyon, Olivier; Harris, Walter M.; Hirata, Chris; Mather, John C.; Redding, David; Schiminovich, David; Stahl, H. Philip

2015-01-01

We report on the AURA 'Beyond JWST' committee's considerations and conclusions regarding the science case for the development of a large UVOIR observatory, to be launched following JWST and WFIRST-AFTA. We find that a space-based UVOIR telescope of 10 meters or more in aperture will uniquely enable a wide range of transformational science investigations by itself and in tandem with ground-based OIR and radio facilities in its era. The chief goal of this facility is to assess the possibility of life beyond our Solar System by discovering Earth-like planets in the habitable zones of their host stars, via direct imaging, and by searching spectroscopically for biosignature gases in the atmospheres of the best exo-Earth candidates. The large aperture and mission architecture required to characterize the atmospheres of a significant number of potentially life-bearing planets will also transform studies of the galaxies and stars that led up to them. At 10 meters or larger, the telescope will spatially resolve scales of 100 AU everywhere in the Milky Way, 0.1 parsec everywhere in the Local Group, and 100 parsec everywhere in the observable Universe. This unprecedented spatial resolution over large fields, with stable optics and low backgrounds, will allow astronomers to follow, in high definition, the formation and evolution of the star forming regions inside galaxies over the past 10 Gyr, to robustly determine the complete star formation histories in every galaxy within the local volume (to 10 Mpc), and to track the motions of virtually any star in the Milky Way. High spectral resolution and multi-object spectroscopy in the UV will enable revolutionary new studies of gas flows in galaxies, bodies in the outer solar system, and the evolution of the most massive stars. We present these compelling science drivers and their associated observational requirements here; we summarize the technology requirements for high angular resolution, sensitivity, wavefront stability

THE GREEN BANK TELESCOPE 350 MHz DRIFT-SCAN SURVEY. I. SURVEY OBSERVATIONS AND THE DISCOVERY OF 13 PULSARS

Energy Technology Data Exchange (ETDEWEB)

Boyles, J.; Lorimer, D. R.; McLaughlin, M. A.; Cardoso, R. F. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Lynch, R. S.; Kaspi, V. M.; Archibald, A.; Karako-Argaman, C. [Department of Physics, McGill University, 3600 University St., Montreal, Quebec, H3A 2T8 (Canada); Ransom, S. M. [National Radio Astronomy Observatory (NRAO), 520 Edgemont Road, Charlottesville, VA 22901 (United States); Stairs, I. H.; Berndsen, A.; Cherry, A.; McPhee, C. A. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Hessels, J. W. T.; Kondratiev, V. I.; Van Leeuwen, J. [ASTRON, The Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); Epstein, C. R. [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Pennucci, T. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Roberts, M. S. E. [Eureka Scientific, 2452 Delmer Street, Suite 100, Oakland, CA 94602-3017 (United States); Stovall, K., E-mail: jason.boyles@wku.edu [Center for Advanced Radio Astronomy and Department of Physics and Astronomy, University of Texas at Brownsville, Brownsville, TX 78520 (United States)

2013-02-15

Over the summer of 2007, we obtained 1191 hr of 'drift-scan' pulsar search observations with the Green Bank Telescope at a radio frequency of 350 MHz. Here we describe the survey setup, search procedure, and the discovery and follow-up timing of 13 pulsars. Among the new discoveries, one (PSR J1623-0841) was discovered only through its single pulses, two (PSRs J1327-0755 and J1737-0814) are millisecond pulsars, and another (PSR J2222-0137) is a mildly recycled pulsar. PSR J1327-0755 is a 2.7 ms pulsar at a dispersion measure (DM) of 27.9 pc cm{sup -3} in an 8.7 day orbit with a minimum companion mass of 0.22 M {sub Sun }. PSR J1737-0814 is a 4.2 ms pulsar at a DM of 55.3 pc cm{sup -3} in a 79.3 day orbit with a minimum companion mass of 0.06 M {sub Sun }. PSR J2222-0137 is a 32.8 ms pulsar at a very low DM of 3.27 pc cm{sup -3} in a 2.4 day orbit with a minimum companion mass of 1.11 M {sub Sun }. It is most likely a white-dwarf-neutron-star system or an unusual low-eccentricity double neutron star system. Ten other pulsars discovered in this survey are reported in the companion paper Lynch et al.

Ghost telescope and ghost Fourier telescope with thermal light

International Nuclear Information System (INIS)

Gong Wenlin; Han Shensheng

2011-01-01

As important observation tools, telescopes are very useful in remote observations. We report a proof-of-principle experimental demonstration of ghost telescope scheme and show that, by measuring the intensity correlation of two light fields and only changing the position of the detector in the reference path, ghost telescope and ghost Fourier telescope can be obtained even if a single-pixel detector is fixed in Fresnel region of the object. Differences between conventional telescope and ghost telescope are also discussed.

VLTI auxiliary telescopes: a full object-oriented approach

Science.gov (United States)

Chiozzi, Gianluca; Duhoux, Philippe; Karban, Robert

2000-06-01

The Very Large Telescope (VLT) Telescope Control Software (TCS) is a portable system. It is now in use or will be used in a whole family of ESO telescopes VLT Unit Telescopes, VLTI Auxiliary Telescopes, NTT, La Silla 3.6, VLT Survey Telescope and Astronomical Site Monitors in Paranal and La Silla). Although it has been developed making extensive usage of Object Oriented (OO) methodologies, the overall development process chosen at the beginning of the project used traditional methods. In order to warranty a longer lifetime to the system (improving documentation and maintainability) and to prepare for future projects, we have introduced a full OO process. We have taken as a basis the United Software Development Process with the Unified Modeling Language (UML) and we have adapted the process to our specific needs. This paper describes how the process has been applied to the VLTI Auxiliary Telescopes Control Software (ATCS). The ATCS is based on the portable VLT TCS, but some subsystems are new or have specific characteristics. The complete process has been applied to the new subsystems, while reused code has been integrated in the UML models. We have used the ATCS on one side to tune the process and train the team members and on the other side to provide a UML and WWW based documentation for the portable VLT TCS.

Radio Frequency Interference Site Survey for Thai Radio Telescopes

Science.gov (United States)

Jaroenjittichai, P.; Punyawarin, S.; Singwong, D.; Somboonpon, P.; Prasert, N.; Bandudej, K.; Kempet, P.; Leckngam, A.; Poshyachinda, S.; Soonthornthum, B.; Kramer, B.

2017-09-01

Radio astronomical observations have increasingly been threaten by the march of today telecommunication and wireless technology. Performance of radio telescopes lies within the fact that astronomical sources are extremely weak. National Astronomy Research Institute of Thailand (NARIT) has initiated a 5-year project, known as the Radio Astronomy Network and Geodesy for Development (RANGD), which includes the establishment of 40-meter and 13-meter radio telescopes. Possible locations have been narrowed down to three candidates, situated in the Northern part of Thailand, where the atmosphere is sufficiently dry and suitable for 22 and 43 GHz observations. The Radio Frequency Interference (RFI) measurements were carried out with a DC spectrum analyzer and directional antennas at 1.5 meter above ground, from 20 MHz to 6 GHz with full azimuth coverage. The data from a 3-minute pointing were recorded for both horizontal and vertical polarizations, in maxhold and average modes. The results, for which we used to make preliminary site selection, show signals from typical broadcast and telecommunication services and aeronautics applications. The signal intensity varies accordingly to the presence of nearby population and topography of the region.

Origins Space Telescope: Study Plan

Science.gov (United States)

Nayyeri, Hooshang; Cooray, Asantha; Origins Space Telescope Study Team

2018-01-01

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.

DETECTION OF E-CYANOMETHANIMINE TOWARD SAGITTARIUS B2(N) IN THE GREEN BANK TELESCOPE PRIMOS SURVEY

Energy Technology Data Exchange (ETDEWEB)

Zaleski, Daniel P.; Seifert, Nathan A.; Steber, Amanda L.; Muckle, Matt T.; Loomis, Ryan A.; Vasquez, David; Nyiramahirwe, Jolie; Sciortino, Nicole; Johnson, Kennedy; Pate, Brooks H. [Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, VA 22904 (United States); Corby, Joanna F. [Department of Astronomy, University of Virginia, McCormick Road, Charlottesville, VA 22904 (United States); Martinez, Oscar Jr.; Crabtree, Kyle N.; McCarthy, Michael C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Jewell, Philip R.; Remijan, Anthony J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Hollis, Jan M. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Lovas, Frank J., E-mail: bp2k@virginia.edu, E-mail: mccarthy@cfa.harvard.edu, E-mail: aremijan@nrao.edu [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

2013-03-01

The detection of E-cyanomethanimine (E-HNCHCN) toward Sagittarius B2(N) is made by comparing the publicly available Green Bank Telescope (GBT) PRIMOS survey spectra to laboratory rotational spectra from a reaction product screening experiment. The experiment uses broadband molecular rotational spectroscopy to monitor the reaction products produced in an electric discharge source using a gas mixture of NH{sub 3} and CH{sub 3}CN. Several transition frequency coincidences between the reaction product screening spectra and previously unassigned interstellar rotational transitions in the PRIMOS survey have been assigned to E-cyanomethanimine. A total of eight molecular rotational transitions of this molecule between 9 and 50 GHz are observed with the GBT. E-cyanomethanimine, often called the HCN dimer, is an important molecule in prebiotic chemistry because it is a chemical intermediate in proposed synthetic routes of adenine, one of the two purine nucleobases found in DNA and RNA. New analyses of the rotational spectra of both E-cyanomethanimine and Z-cyanomethanimine that incorporate previous millimeter-wave measurements are also reported.

DETECTION OF E-CYANOMETHANIMINE TOWARD SAGITTARIUS B2(N) IN THE GREEN BANK TELESCOPE PRIMOS SURVEY

International Nuclear Information System (INIS)

Zaleski, Daniel P.; Seifert, Nathan A.; Steber, Amanda L.; Muckle, Matt T.; Loomis, Ryan A.; Vasquez, David; Nyiramahirwe, Jolie; Sciortino, Nicole; Johnson, Kennedy; Pate, Brooks H.; Corby, Joanna F.; Martinez, Oscar Jr.; Crabtree, Kyle N.; McCarthy, Michael C.; Jewell, Philip R.; Remijan, Anthony J.; Hollis, Jan M.; Lovas, Frank J.

2013-01-01

The detection of E-cyanomethanimine (E-HNCHCN) toward Sagittarius B2(N) is made by comparing the publicly available Green Bank Telescope (GBT) PRIMOS survey spectra to laboratory rotational spectra from a reaction product screening experiment. The experiment uses broadband molecular rotational spectroscopy to monitor the reaction products produced in an electric discharge source using a gas mixture of NH 3 and CH 3 CN. Several transition frequency coincidences between the reaction product screening spectra and previously unassigned interstellar rotational transitions in the PRIMOS survey have been assigned to E-cyanomethanimine. A total of eight molecular rotational transitions of this molecule between 9 and 50 GHz are observed with the GBT. E-cyanomethanimine, often called the HCN dimer, is an important molecule in prebiotic chemistry because it is a chemical intermediate in proposed synthetic routes of adenine, one of the two purine nucleobases found in DNA and RNA. New analyses of the rotational spectra of both E-cyanomethanimine and Z-cyanomethanimine that incorporate previous millimeter-wave measurements are also reported.

The Atacama Cosmology Telescope: Extragalactic Sources at 148 GHz in the 2008 Survey

Science.gov (United States)

Marriage, T. A.; Juin, J. B.; Lin, Y. T.; Marsden, D.; Nolta, M. R.; Partridge, B.; Ade, P. A. R.; Aguirre, P.; Amiri, M.; Appel, J. W.;

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.

The Nuclear Spectroscopic Telescope Array (NuSTAR)

DEFF Research Database (Denmark)

Harrison, Fiona A.; Boggs, Steve; Christensen, Finn Erland

2010-01-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission that will carry the first focusing hard X-ray (6 - 80 keV) telescope to orbit. NuSTAR will offer a factor 50 - 100 sensitivity improvement compared to previous collimated or coded mask imagers that have operated...... in this energy band. In addition, NuSTAR provides sub-arcminute imaging with good spectral resolution over a 12-arcminute eld of view. After launch, NuSTAR will carry out a two-year primary science mission that focuses on four key programs: studying the evolution of massive black holes through surveys carried...... on-orbit deployment of an extendable mast. An aspect and alignment metrology system enable reconstruction of the absolute aspect and variations in the telescope alignment resulting from mast exure during ground data processing. Data will be publicly available at GSFC's High Energy Archive Research...

The all-sky 408 MHz survey

International Nuclear Information System (INIS)

Haslam, C.G.T.; Salter, C.J.; Stoffel, H.

1981-01-01

A brief outline of the results of this survey is presented. The 408 MHz All-sky Survey has been made from four radio continuum surveys observed between 1965 and 1978, using the Jodrell Bank MKI telescope (Haslam et al., 1970), the Effelsberg 100 metre telescope (Haslam et al., 1974) and the Parkes 64 metre telescope (Haslam et al., 1975). A detailed description of the survey data reduction and calibration methods, with preliminary astronomical results will soon be published (Haslam et al., 1980a) and a second paper will give an atlas of maps at the full survey resolution of 51' arc between half power points (Haslam et al., 1980b). A map, smoothed to a gaussian beam with resolution between half power poitns of 3 0 , is presented. (Auth.)

THE DISTRIBUTION OF FAINT SATELLITES AROUND CENTRAL GALAXIES IN THE CANADA-FRANCE-HAWAII TELESCOPE LEGACY SURVEY

Energy Technology Data Exchange (ETDEWEB)

Jiang, C. Y.; Jing, Y. P.; Li, Cheng [Key Laboratory for Research in Galaxies and Cosmology of Chinese Academy of Sciences, Shanghai Astronomical Observatory, Nandan Road 80, Shanghai 200030 (China)

2012-11-20

We investigate the radial number density profile and the abundance distribution of faint satellites around central galaxies in the low-redshift universe using the Canada-France-Hawaii Telescope (CFHT) Legacy Survey. We consider three samples of central galaxies with magnitudes of M {sub r} = -21, -22, and -23 selected from the Sloan Digital Sky Survey group catalog of Yang et al. The satellite distribution around these central galaxies is obtained by cross-correlating these galaxies with the photometric catalog of the CFHT Legacy Survey. The projected radial number density of the satellites obeys a power-law form with the best-fit logarithmic slope of -1.05, independent of both the central galaxy luminosity and the satellite luminosity. The projected cross-correlation function between central and satellite galaxies exhibits a non-monotonic trend with satellite luminosity. It is most pronounced for central galaxies with M {sub r} = -21, where the decreasing trend of clustering amplitude with satellite luminosity is reversed when satellites are fainter than central galaxies by more than 2 mag. A comparison with the satellite luminosity functions in the Milky Way (MW) and M31 shows that the MW/M31 system has about twice as many satellites as around a typical central galaxy of similar luminosity. The implications for theoretical models are briefly discussed.

First Steps Toward K-12 Teacher Professional Development Using Internet-based Telescopes

Science.gov (United States)

Berryhill, K. J.; Gershun, D.; Slater, T. F.; Armstrong, J. D.

2012-12-01

How can science teachers become more familiar with emerging technology, excite their students and give students a taste of astronomy research? Astronomy teachers do not always have research experience, so it is difficult for them to convey to students how researchers use telescopes. The nature of astronomical observation (e.g., remote sites, expensive equipment, and odd hours) has been a barrier to providing teachers with insight into the process. Robotic telescopes (operated automatically with queued observing schedules) and remotely controlled telescopes (controlled by the user via the Internet) allow scientists to conduct observing sessions on research-grade telescopes half a world away. The same technology can now be harnessed by STEM educators to engage students and reinforce what is being taught in the classroom, as seen in some early research in elementary schools (McKinnon and Mainwaring 2000 and McKinnon and Geissinger 2002), and middle/high schools (Sadler et al. 2001, 2007 and Gehret et al. 2005). However, teachers need to be trained to use these resources. Responding to this need, graduate students and faculty at the University of Wyoming and CAPER Center for Astronomy & Physics Education Research are developing teacher professional development programs using Internet-based telescopes. We conducted an online course in the science education graduate program at the University of Wyoming. This course was designed to sample different types of Internet-based telescopes to evaluate them as resources for teacher professional development. The 10 participants were surveyed at the end of the course to assess their experiences with each activity. In addition, pre-test/post-test data were collected focusing specifically on one of the telescopes (Gershun, Berryhill and Slater 2012). Throughout the course, the participants learned to use a variety of robotic and remote telescopes including SLOOH Space Camera (www.slooh.com), Sky Titan Observatory (www

Britain Approaches ESO about Installation of Major New Telescope at Paranal

Science.gov (United States)

2000-02-01

The Executive Board of the UK Visible and Infrared Survey Telescope (VISTA) project announced today [1] that it is aiming at the installation of a new and powerful astronomical telescope at the ESO Paranal Observatory (Chile). This 4-metre telescope is a specialised wide-angle facility equipped with powerful cameras and efficient detectors that will enable it to obtain deep images of large sky areas in short time. These survey observations will be made in several wavebands in the optical and, in particular, the near-infrared region of the electromagnetic spectrum. VISTA will become the largest and most effective telescope of its type when it enters into operation in 2004. It is a project of a consortium of 18 UK universities [2]. Construction is expected to start in spring 2000. Funding of the project was announced in May 1999, as one of the first allocations from the "Joint Infrastructure Fund (JIF)", an initiative of the UK Government's Department of Trade and Industry, the Wellcome Trust, and the Higher Education Funding Council for England. ESO's Director General, Dr. Catherine Cesarsky , is very pleased with this decision. She received a mandate from the ESO Council in December 1999 to negotiate a contract with the UK Particle Physics and Astronomy Research Council (PPARC) , acting on behalf of the VISTA Executive Board, for the installation of VISTA at Paranal and now looks forward to settle the associated legal and operational details with her British counterparts at good pace. "The installation of VISTA at Paranal will be of great benefit to all European astronomers", she says. "The placement of a survey telescope of this size next to ESO's VLT, the world's largest optical telescope, opens a plethora of exciting opportunities for joint research projects. Deep observations with VISTA, especially in infrared wavebands, will provide a most valuable, first census of large regions of space. This will most certainly lead to the discoveries of many new and

Swift Burst Alert Telescope Data Products and Analysis Software

International Nuclear Information System (INIS)

Krimm, Hans A.; Barbier, Louis M.; Barthelmy, Scott D.; Cummings, Jay R.; Gehrels, Neil; Parsons, Ann M.; Tueller, Jack; Fenimore, Edward E.; Palmer, David M.; Hullinger, Derek D.; Markwardt, Craig B.

2004-01-01

The Burst Alert Telescope (BAT) on the Swift gamma-ray burst mission serves as the GRB trigger for Swift as well as a sensitive imaging telescope for the energy range of 15-150 keV. All BAT data products will be available to the astronomical community along with a complete set of analysis tools. Gamma-ray burst data products include rapid discovery messages delivered immediately via the GRB Coordinates Network, and event-by-event data from which light curves and spectra of the burst are generated. During nominal operations, the instrument provides accumulated survey histograms with 5-minute time sampling and appropriate energy resolution. These survey accumulations are analyzed in a pipeline to detect new sources and derive light curves of known sources. The 5-minute surveys will also be combined to produce the BAT all sky hard X-ray survey. In addition, the instrument accumulates high time resolution light curves of the brightest BAT sources in multiple energy bands, which are merged into a source light curve database on the ground. The BAT science data products and analysis tools will be described in this paper

Performance Improvement of Near Earth Space Survey (NESS Wide-Field Telescope (NESS-2 Optics

Directory of Open Access Journals (Sweden)

Sung-Yeol Yu

2010-06-01

Full Text Available We modified the optical system of 500 mm wide-field telescope of which point spread function showed an irregularity. The telescope has been operated for Near Earth Space Survey (NESS located at Siding Spring Observatory (SSO in Australia, and the optical system was brought back to Korea in January 2008. After performing a numerical simulation with the tested value of surface figure error of the primary mirror using optical design program, we found that the surface figure error of the mirror should be fabricated less than root mean square (RMS λ/10 in order to obtain a stellar full width at half maximum (FWHM below 28 μm. However, we started to figure the mirror for the target value of RMS λ/20, because system surface figure error would be increased by the error induced by the optical axis adjustment, mirror cell installation, and others. The radius of curvature of the primary mirror was 1,946 mm after the correction. Its measured surface figure error was less than RMS λ/20 on the table of polishing machine, and RMS λ/15 after installation in the primary mirror cell. A test observation performed at Daeduk Observatory at Korea Astronomy and Space Science Institute by utilizing the exiting mount, and resulted in 39.8 μm of stellar FWHM. It was larger than the value from numerical simulation, and showed wing-shaped stellar image. It turned out that the measured-curvature of the secondary mirror, 1,820 mm, was not the same as the designed one, 1,795.977 mm. We fabricated the secondary mirror to the designed value, and finally obtained a stellar FWHM of 27 μm after re-installation of the optical system into SSO NESS Observatory in Australia.

Characterizing Cool Giant Planets in Reflected Light

Science.gov (United States)

Marley, Mark

2016-01-01

While the James Webb Space Telescope will detect and characterize extrasolar planets by transit and direct imaging, a new generation of telescopes will be required to detect and characterize extrasolar planets by reflected light imaging. NASA's WFIRST space telescope, now in development, will image dozens of cool giant planets at optical wavelengths and will obtain spectra for several of the best and brightest targets. This mission will pave the way for the detection and characterization of terrestrial planets by the planned LUVOIR or HabEx space telescopes. In my presentation I will discuss the challenges that arise in the interpretation of direct imaging data and present the results of our group's effort to develop methods for maximizing the science yield from these planned missions.

Precision cosmology with time delay lenses: high resolution imaging requirements

Energy Technology Data Exchange (ETDEWEB)

Meng, Xiao-Lei; Liao, Kai [Department of Astronomy, Beijing Normal University, 19 Xinjiekouwai Street, Beijing, 100875 (China); Treu, Tommaso; Agnello, Adriano [Department of Physics, University of California, Broida Hall, Santa Barbara, CA 93106 (United States); Auger, Matthew W. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Marshall, Philip J., E-mail: xlmeng919@gmail.com, E-mail: tt@astro.ucla.edu, E-mail: aagnello@physics.ucsb.edu, E-mail: mauger@ast.cam.ac.uk, E-mail: liaokai@mail.bnu.edu.cn, E-mail: dr.phil.marshall@gmail.com [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305 (United States)

2015-09-01

Lens time delays are a powerful probe of cosmology, provided that the gravitational potential of the main deflector can be modeled with sufficient precision. Recent work has shown that this can be achieved by detailed modeling of the host galaxies of lensed quasars, which appear as ''Einstein Rings'' in high resolution images. The distortion of these arcs and counter-arcs, as measured over a large number of pixels, provides tight constraints on the difference between the gravitational potential between the quasar image positions, and thus on cosmology in combination with the measured time delay. We carry out a systematic exploration of the high resolution imaging required to exploit the thousands of lensed quasars that will be discovered by current and upcoming surveys with the next decade. Specifically, we simulate realistic lens systems as imaged by the Hubble Space Telescope (HST), James Webb Space Telescope (JWST), and ground based adaptive optics images taken with Keck or the Thirty Meter Telescope (TMT). We compare the performance of these pointed observations with that of images taken by the Euclid (VIS), Wide-Field Infrared Survey Telescope (WFIRST) and Large Synoptic Survey Telescope (LSST) surveys. We use as our metric the precision with which the slope γ' of the total mass density profile ρ{sub tot}∝ r{sup −γ'} for the main deflector can be measured. Ideally, we require that the statistical error on γ' be less than 0.02, such that it is subdominant to other sources of random and systematic uncertainties. We find that survey data will likely have sufficient depth and resolution to meet the target only for the brighter gravitational lens systems, comparable to those discovered by the SDSS survey. For fainter systems, that will be discovered by current and future surveys, targeted follow-up will be required. However, the exposure time required with upcoming facilitites such as JWST, the Keck Next Generation

Precision cosmology with time delay lenses: High resolution imaging requirements

Energy Technology Data Exchange (ETDEWEB)

Meng, Xiao -Lei [Beijing Normal Univ., Beijing (China); Univ. of California, Santa Barbara, CA (United States); Treu, Tommaso [Univ. of California, Santa Barbara, CA (United States); Univ. of California, Los Angeles, CA (United States); Agnello, Adriano [Univ. of California, Santa Barbara, CA (United States); Univ. of California, Los Angeles, CA (United States); Auger, Matthew W. [Univ. of Cambridge, Cambridge (United Kingdom); Liao, Kai [Beijing Normal Univ., Beijing (China); Univ. of California, Santa Barbara, CA (United States); Univ. of California, Los Angeles, CA (United States); Marshall, Philip J. [Stanford Univ., Stanford, CA (United States)

2015-09-28

Lens time delays are a powerful probe of cosmology, provided that the gravitational potential of the main deflector can be modeled with sufficient precision. Recent work has shown that this can be achieved by detailed modeling of the host galaxies of lensed quasars, which appear as ``Einstein Rings'' in high resolution images. The distortion of these arcs and counter-arcs, as measured over a large number of pixels, provides tight constraints on the difference between the gravitational potential between the quasar image positions, and thus on cosmology in combination with the measured time delay. We carry out a systematic exploration of the high resolution imaging required to exploit the thousands of lensed quasars that will be discovered by current and upcoming surveys with the next decade. Specifically, we simulate realistic lens systems as imaged by the Hubble Space Telescope (HST), James Webb Space Telescope (JWST), and ground based adaptive optics images taken with Keck or the Thirty Meter Telescope (TMT). We compare the performance of these pointed observations with that of images taken by the Euclid (VIS), Wide-Field Infrared Survey Telescope (WFIRST) and Large Synoptic Survey Telescope (LSST) surveys. We use as our metric the precision with which the slope γ' of the total mass density profile ρ_tot∝ r–γ' for the main deflector can be measured. Ideally, we require that the statistical error on γ' be less than 0.02, such that it is subdominant to other sources of random and systematic uncertainties. We find that survey data will likely have sufficient depth and resolution to meet the target only for the brighter gravitational lens systems, comparable to those discovered by the SDSS survey. For fainter systems, that will be discovered by current and future surveys, targeted follow-up will be required. Furthermore, the exposure time required with upcoming facilitites such as JWST, the Keck Next Generation Adaptive

Galaxy morphologies in the era of big-data surveys

Science.gov (United States)

Huertas-Company, M.

Galaxy morphology is a first-order descriptor of a galaxy and a useful proxy to identify physical processes. The 100 years old Hubble fork describes the structural diversity of galaxies in the local universe. Unveiling the origins of this galaxy zoology is a key challenge in galaxy evolution. In this review talk, I first summarized some key advances in our understanding of the morphological evolution of galaxies from z ~ 0 to z ~ 3, thank you in particular to the SDSS and HST legacies. In the second part, I focused on the classification techniques. With the emergence in the last years of large surveys the samples of study have increased by several orders of magnitude going from a few tens to several millions of objects. This trend will clearly continue in the next decade with coming surveys/missions such as EUCLID and WFIRST. While galaxy classification is still a required step in any survey, visual inspection of galaxies is becoming prohibitively time-consuming. Under these circumstances, the techniques used to estimate galaxy morphologies need to be updated.

THE GREEN BANK TELESCOPE H II REGION DISCOVERY SURVEY. III. KINEMATIC DISTANCES

Energy Technology Data Exchange (ETDEWEB)

Anderson, L. D. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States); Bania, T. M. [Institute for Astrophysical Research, Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Balser, Dana S. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Rood, Robert T., E-mail: Loren.Anderson@mail.wvu.edu [Astronomy Department, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903-0818 (United States)

2012-07-20

Using the H I emission/absorption method, we resolve the kinematic distance ambiguity and derive distances for 149 of 182 (82%) H II regions discovered by the Green Bank Telescope H II Region Discovery Survey (GBT HRDS). The HRDS is an X-band (9 GHz, 3 cm) GBT survey of 448 previously unknown H II regions in radio recombination line and radio continuum emission. Here, we focus on HRDS sources from 67 Degree-Sign {>=} l {>=} 18 Degree-Sign , where kinematic distances are more reliable. The 25 HRDS sources in this zone that have negative recombination line velocities are unambiguously beyond the orbit of the Sun, up to 20 kpc distant. They are the most distant H II regions yet discovered. We find that 61% of HRDS sources are located at the far distance, 31% at the tangent-point distance, and only 7% at the near distance. 'Bubble' H II regions are not preferentially located at the near distance (as was assumed previously) but average 10 kpc from the Sun. The HRDS nebulae, when combined with a large sample of H II regions with previously known distances, show evidence of spiral structure in two circular arc segments of mean Galactocentric radii of 4.25 and 6.0 kpc. We perform a thorough uncertainty analysis to analyze the effect of using different rotation curves, streaming motions, and a change to the solar circular rotation speed. The median distance uncertainty for our sample of H II regions is only 0.5 kpc, or 5%. This is significantly less than the median difference between the near and far kinematic distances, 6 kpc. The basic Galactic structure results are unchanged after considering these sources of uncertainty.

Toward an Autonomous Telescope Network: the TBT Scheduler

Science.gov (United States)

Racero, E.; Ibarra, A.; Ocaña, F.; de Lis, S. B.; Ponz, J. D.; Castillo, M.; Sánchez-Portal, M.

2015-09-01

Within the ESA SSA program, it is foreseen to deploy several robotic telescopes to provide surveillance and tracking services for hazardous objects. The TBT project will procure a validation platform for an autonomous optical observing system in a realistic scenario, consisting of two telescopes located in Spain and Australia, to collect representative test data for precursor SSA services. In this context, the planning and scheduling of the night consists of two software modules, the TBT Scheduler, that will allow the manual and autonomous planning of the night, and the control of the real-time response of the system, done by the RTS2 internal scheduler. The TBT Scheduler allocates tasks for both telescopes without human intervention. Every night it takes all the inputs needed and prepares the schedule following some predefined rules. The main purpose of the scheduler is the distribution of the time for follow-up of recently discovered targets and surveys. The TBT Scheduler considers the overall performance of the system, and combine follow-up with a priori survey strategies for both kind of objects. The strategy is defined according to the expected combined performance for both systems the upcoming night (weather, sky brightness, object accessibility and priority). Therefore, TBT Scheduler defines the global approach for the network and relies on the RTS2 internal scheduler for the final detailed distribution of tasks at each sensor.

FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN): Molecular clouds toward W 33; possible evidence for a cloud-cloud collision triggering O star formation

Science.gov (United States)

Kohno, Mikito; Torii, Kazufumi; Tachihara, Kengo; Umemoto, Tomofumi; Minamidani, Tetsuhiro; Nishimura, Atsushi; Fujita, Shinji; Matsuo, Mitsuhiro; Yamagishi, Mitsuyoshi; Tsuda, Yuya; Kuriki, Mika; Kuno, Nario; Ohama, Akio; Hattori, Yusuke; Sano, Hidetoshi; Yamamoto, Hiroaki; Fukui, Yasuo

2018-05-01

We observed molecular clouds in the W 33 high-mass star-forming region associated with compact and extended H II regions using the NANTEN2 telescope as well as the Nobeyama 45 m telescope in the J = 1-0 transitions of 12CO, 13CO, and C18O as part of the FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45 m telescope (FUGIN) legacy survey. We detected three velocity components at 35 km s-1, 45 km s-1, and 58 km s-1. The 35 km s-1 and 58 km s-1 clouds are likely to be physically associated with W 33 because of the enhanced 12CO J = 3-2 to J = 1-0 intensity ratio as R_3-2/1-0} > 1.0 due to the ultraviolet irradiation by OB stars, and morphological correspondence between the distributions of molecular gas and the infrared and radio continuum emissions excited by high-mass stars. The two clouds show complementary distributions around W 33. The velocity separation is too large to be gravitationally bound, and yet not explained by expanding motion by stellar feedback. Therefore, we discuss whether a cloud-cloud collision scenario likely explains the high-mass star formation in W 33.

Mosaic3: a red-sensitive upgrade for the prime focus camera at the Mayall 4m telescope

Science.gov (United States)

Dey, Arjun; Rabinowitz, David; Karcher, Armin; Bebek, Chris; Baltay, Charles; Sprayberry, David; Valdes, Frank; Stupak, Bob; Donaldson, John; Emmet, Will; Hurteau, Tom; Abareshi, Behzad; Marshall, Bob; Lang, Dustin; Fitzpatrick, Mike; Daly, Phil; Joyce, Dick; Schlegel, David; Schweiker, Heidi; Allen, Lori; Blum, Bob; Levi, Michael

2016-08-01

The Dark Energy Spectroscopic Instrument (DESI) is under construction and will be used to measure the expansion history of the Universe using the Baryon Acoustic Oscillation (BAO) technique and the growth of structure using redshift-space distortions (RSD). The spectra of 30 million galaxies over 14000 sq deg will be measured over the course of the experiment. In order to provide spectroscopic targets for the DESI survey, we are carrying out a three-band (g,r,z ) imaging survey of the sky using the NOAO 4-m telescopes at Kitt Peak National Observatory (KPNO) and the Cerro Tololo Interamerican Observatory (CTIO). At KPNO, we will use an upgraded version of the Mayall 4m telescope prime focus camera, Mosaic3, to carry out a z-band survey of the Northern Galactic Cap at declinations δ>=+30 degrees. By equipping an existing Dewar with four 4kx4k fully depleted CCDs manufactured by the Lawrence Berkeley National Laboratory (LBNL), we increased the z-band throughput of the system by a factor of 1.6. These devices have the thickest active area fielded at a telescope. The Mosaic3 z-band survey will be complemented by g-band and r-band observations using the Bok telescope and 90 Prime imager on Kitt Peak. We describe the upgrade and performance of the Mosaic3 instrument and the scope of the northern survey.

The space telescope: A study of NASA, science, technology, and politics

Science.gov (United States)

Smith, Robert William

1989-01-01

Scientific, technological, economic, and political aspects of NASA efforts to orbit a large astronomical telescope are examined in a critical historical review based on extensive interviews with participants and analysis of published and unpublished sources. The scientific advantages of large space telescopes are explained; early plans for space observatories are summarized; the history of NASA and its major programs is surveyed; the redesign of the original Large Space Telescope for Shuttle deployability is discussed; the impact of the yearly funding negotiations with Congress on the development of the final Hubble Space Telescope (HST) is described; and the implications of the HST story for the future of large space science projects are explored. Drawings, photographs, a description of the HST instruments and systems, and lists of the major contractors and institutions participating in the HST program are provided.

THE GREEN BANK TELESCOPE 350 MHz DRIFT-SCAN SURVEY II: DATA ANALYSIS AND THE TIMING OF 10 NEW PULSARS, INCLUDING A RELATIVISTIC BINARY

Energy Technology Data Exchange (ETDEWEB)

Lynch, Ryan S.; Kaspi, Victoria M.; Archibald, Anne M.; Karako-Argaman, Chen [Department of Physics, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Boyles, Jason; Lorimer, Duncan R.; McLaughlin, Maura A.; Cardoso, Rogerio F. [Department of Physics, West Virginia University, 111 White Hall, Morgantown, WV 26506 (United States); Ransom, Scott M. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Stairs, Ingrid H.; Berndsen, Aaron; Cherry, Angus; McPhee, Christie A. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Hessels, Jason W. T.; Kondratiev, Vladislav I.; Van Leeuwen, Joeri [ASTRON, The Netherlands Institute for Radio Astronomy, Postbus 2, 7990-AA Dwingeloo (Netherlands); Epstein, Courtney R. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Pennucci, Tim [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); Roberts, Mallory S. E. [Eureka Scientific Inc., 2452 Delmer Street, Suite 100, Oakland, CA 94602 (United States); Stovall, Kevin, E-mail: rlynch@physics.mcgill.ca [Center for Advanced Radio Astronomy and Department of Physics and Astronomy, University of Texas at Brownsville, Brownsville, TX 78520 (United States)

2013-02-15

We have completed a 350 MHz Drift-scan Survey using the Robert C. Byrd Green Bank Telescope with the goal of finding new radio pulsars, especially millisecond pulsars that can be timed to high precision. This survey covered {approx}10,300 deg{sup 2} and all of the data have now been fully processed. We have discovered a total of 31 new pulsars, 7 of which are recycled pulsars. A companion paper by Boyles et al. describes the survey strategy, sky coverage, and instrumental setup, and presents timing solutions for the first 13 pulsars. Here we describe the data analysis pipeline, survey sensitivity, and follow-up observations of new pulsars, and present timing solutions for 10 other pulsars. We highlight several sources-two interesting nulling pulsars, an isolated millisecond pulsar with a measurement of proper motion, and a partially recycled pulsar, PSR J0348+0432, which has a white dwarf companion in a relativistic orbit. PSR J0348+0432 will enable unprecedented tests of theories of gravity.

A Galaxy Zoo - WorldWide Telescope Mashup: Expanding User Defined Exploration

Science.gov (United States)

Luebbert, Jarod; Sands, M.; Fay, J.; Smith, A.; Gay, P. L.; Galaxy Zoo Team

2010-01-01

We present a new way of exploring your favorite Galaxy Zoo galaxies within the context of the sky using Microsoft Research's WorldWide Telescope. Galaxy Zoo has a fantastic community that is eager to learn and contribute to science through morphological classifications of galaxies. WorldWide Telescope is an interactive observatory that allows users to explore the sky. WorldWide Telescope uses images from the world's best telescopes, including the galaxies of the Sloan Digital Sky Survey. WorldWide Telescope provides a fantastic sense of size and distance that is hard to experience in Galaxy Zoo. Creating tours from favorite galaxies directly from Galaxy Zoo aims to solve this dilemma.The incorporation of Galaxy Zoo and WorldWide telescope provides a great resource for users to learn more about the galaxies they are classifying. Users can now explore the areas around certain galaxies and view information about that location from within WorldWide Telescope. Not only does this encourage self-motivated research but after tours are created they can be shared with anyone. We hope this will help spread citizen science to different audiences via email, Facebook, and Twitter.Without the WorldWide Telescope team at Microsoft Research this project would not have been possible. Please go start exploring at http://wwt.galaxyzoo.org. This project was funded through the Microsoft Research Academic Program.

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

OpenAIRE

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

2016-01-01

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 re...

FERMI/LARGE AREA TELESCOPE BRIGHT GAMMA-RAY SOURCE LIST

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Atwood, W. B.; Axelsson, M.; Battelino, M.; Baldini, L.; Bellazzini, R.; Ballet, J.; Band, D. L.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bignami, G. F.; Bonamente, E.

2009-01-01

Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the γ-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than ∼10σ) γ-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) γ-ray sources in the early mission data.

Fermi Large Area Telescope Bright Gamma-ray Source List

Energy Technology Data Exchange (ETDEWEB)

Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /KIPAC, Menlo Park /SLAC; Ajello, M.; /KIPAC, Menlo Park /SLAC; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Band, D.L.; /NASA, Goddard /NASA, Goddard; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Bechtol, K.; /KIPAC, Menlo Park /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /KIPAC, Menlo Park /SLAC; Bignami, G.F.; /Pavia U.; Bloom, Elliott D.; /KIPAC, Menlo Park /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /KIPAC, Menlo Park /SLAC; Bregeon, J.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /KIPAC, Menlo Park /SLAC /IASF, Milan /IASF, Milan /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /KIPAC, Menlo Park /SLAC /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /KIPAC, Menlo Park /SLAC /INFN, Perugia /Perugia U. /KIPAC, Menlo Park /SLAC /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /KIPAC, Menlo Park /SLAC /ASDC, Frascati /NASA, Goddard /Maryland U. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /KIPAC, Menlo Park /SLAC /UC, Santa Cruz /KIPAC, Menlo Park /SLAC /KIPAC, Menlo Park /SLAC /KIPAC, Menlo Park /SLAC /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /NASA, Goddard; /more authors..

2009-05-15

Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the {gamma}-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than {approx}10{sigma}) {gamma}-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) {gamma}-ray sources in the early mission data.

Infrared Astronomy Professional Development for K-12 Educators: WISE Telescope

Science.gov (United States)

Borders, Kareen; Mendez, B. M.

2010-01-01

K-12 educators need effective and relevant astronomy professional development. WISE Telescope (Wide-Field Infrared Survey Explorer) and Spitzer Space Telescope Education programs provided an immersive teacher professional development workshop at Arecibo Observatory in Puerto Rico during the summer of 2009. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance of objects in the universe. Teachers built and used basic telescopes, learned about the history of telescopes, explored ground and satellite based telescopes, and explored and worked on models of WISE Telescope. An in-depth explanation of WISE and Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of WISE lenticulars and diagramming of infrared data, listening to light by using speakers hooked up to photoreceptor cells, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars. We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development. Funding was provided by WISE Telescope, Spitzer Space Telescope, Starbucks, Arecibo Observatory, the American Institute of Aeronautics and Astronautics, and the Washington Space Grant Consortium.

Characterizing the Survey Strategy and Initial Orbit Determination Abilities of the NASA MCAT Telescope for Geosynchronous Orbital Debris Environmental Studies

Science.gov (United States)

Frith, James; Barker, Ed; Cowardin, Heather; Buckalew, Brent; Anz-Meado, Phillip; Lederer, Susan

2017-01-01

The NASA Orbital Debris Program Office (ODPO) recently commissioned the Meter Class Autonomous Telescope (MCAT) on Ascension Island with the primary goal of obtaining population statistics of the geosynchronous (GEO) orbital debris environment. To help facilitate this, studies have been conducted using MCAT's known and projected capabilities to estimate the accuracy and timeliness in which it can survey the GEO environment. A simulated GEO debris population is created and sampled at various cadences and run through the Constrained Admissible Region Multi Hypotheses Filter (CAR-MHF). The orbits computed from the results are then compared to the simulated data to assess MCAT's ability to determine accurately the orbits of debris at various sample rates. Additionally, estimates of the rate at which MCAT will be able produce a complete GEO survey are presented using collected weather data and the proposed observation data collection cadence. The specific methods and results are presented here.

A survey of the 5C2 region with the Westerbork synthesis radio telescope at 1415 MHz (the third Westerbork survey), ch. 2

International Nuclear Information System (INIS)

Katgert, P.

1977-01-01

The 5C2 region, observed originally with the Cambridge One-Mile Telescope at 408 MHz, has been reobserved at l4l5 MHz. The resulting source list contains 238 sources with attenuated flux densities exceeding the catalogue limit of 6.25 m.f.u. Out of a total of 190 5C2 sources (i.e. all 5C2 sources within the 10 dB attenuation contour of the present survey), 128 were detected with flux densities above the catalogue limit. Another 22 5C2 sources were detected with flux densities below the catalogue limit. A discussion is given of the procedures used for determining source parameters. Special attention has been given to the determination of flux density and angular size as well as to the question of completeness of the source list as a function of flux density and angular size

Disentangling dark energy and cosmic tests of gravity from weak lensing systematics

Science.gov (United States)

Laszlo, Istvan; Bean, Rachel; Kirk, Donnacha; Bridle, Sarah

2012-06-01

We consider the impact of key astrophysical and measurement systematics on constraints on dark energy and modifications to gravity on cosmic scales. We focus on upcoming photometric ‘stage III’ and ‘stage IV’ large-scale structure surveys such as the Dark Energy Survey (DES), the Subaru Measurement of Images and Redshifts survey, the Euclid survey, the Large Synoptic Survey Telescope (LSST) and Wide Field Infra-Red Space Telescope (WFIRST). We illustrate the different redshift dependencies of gravity modifications compared to intrinsic alignments, the main astrophysical systematic. The way in which systematic uncertainties, such as galaxy bias and intrinsic alignments, are modelled can change dark energy equation-of-state parameter and modified gravity figures of merit by a factor of 4. The inclusion of cross-correlations of cosmic shear and galaxy position measurements helps reduce the loss of constraining power from the lensing shear surveys. When forecasts for Planck cosmic microwave background and stage IV surveys are combined, constraints on the dark energy equation-of-state parameter and modified gravity model are recovered, relative to those from shear data with no systematic uncertainties, provided fewer than 36 free parameters in total are used to describe the galaxy bias and intrinsic alignment models as a function of scale and redshift. While some uncertainty in the intrinsic alignment (IA) model can be tolerated, it is going to be important to be able to parametrize IAs well in order to realize the full potential of upcoming surveys. To facilitate future investigations, we also provide a fitting function for the matter power spectrum arising from the phenomenological modified gravity model we consider.

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...

The Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) Quasar Survey: Quasar Properties from Data Release Two and Three

Science.gov (United States)

Dong, X. Y.; Wu, Xue-Bing; Ai, Y. L.; Yang, J. Y.; Yang, Q.; Wang, F.; Zhang, Y. X.; Luo, A. L.; Xu, H.; Yuan, H. L.; Zhang, J. N.; Wang, M. X.; Wang, L. L.; Li, Y. B.; Zuo, F.; Hou, W.; Guo, Y. X.; Kong, X.; Chen, X. Y.; Wu, Y.; Yang, H. F.; Yang, M.

2018-05-01

This is the second installment for the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) Quasar Survey, which includes quasars observed from 2013 September to 2015 June. There are 9024 confirmed quasars in DR2 and 10911 in DR3. After cross-match with the Sloan Digital Sky Survey (SDSS) quasar catalogs and NED, 12126 quasars are discovered independently. Among them, 2225 quasars were released by SDSS DR12 QSO catalog in 2014 after we finalized the survey candidates. 1801 sources were identified by SDSS DR14 as QSOs. The remaining 8100 quasars are considered as newly founded, and among them, 6887 quasars can be given reliable emission line measurements and the estimated black hole masses. Quasars found in LAMOST are mostly located at low-to-moderate redshifts, with a mean value of 1.5. The highest redshift observed in DR2 and DR3 is 5. We applied emission line measurements to Hα, Hβ, Mg II, and C IV. We deduced the monochromatic continuum luminosities using photometry data, and estimated the virial black hole masses for the newly discovered quasars. Results are compiled into a quasar catalog, which will be available online.

A precursive study of the time-domain survey of the Galactic Anti-center using the Nanshan 1-meter telescope with variable stars detected

Science.gov (United States)

Ma, Shu-Guo; Esamdin, Ali; Ma, Lu; Niu, Hu-Biao; Fu, Jian-Ning; Zhang, Yu; Liu, Jin-Zhong; Yang, Tao-Zhi; Song, Fang-Fang; Pu, Guang-Xin

2018-04-01

Following the LAMOST Spectroscopic Survey and the Xuyi's Photometric Survey of the Galactic Anti-center, we plan to carry out a time-domain survey of the Galactic Anti-center (TDS-GAC) to study variable stars by using the Nanshan 1-meter telescope. Before the beginning of TDS-GAC, a precursive sky survey (PSS) has been executed. The goal of the PSS is to optimize the observation strategy of TDS-GAC and to detect some strong transient events, as well as to find some short time-scale variable stars of different types. By observing a discontinuous sky area of 15.03 deg2 with the standard Johnson-Cousin-Bessel V filter, 48 variable stars are found and the time series are analyzed. Based on the behaviors of the light curves, 28 eclipsing binary stars, 10 RR Lyraes, 3 periodic pulsating variables of other types have been classified. The rest 7 variables stay unclassified with deficient data. In addition, the observation strategy of TD-GAC is described, and the pipeline of data reduction is tested.

The Kilo-Degree Survey

NARCIS (Netherlands)

de Jong, J. T. A.; Kuijken, K.; Applegate, D.; Begeman, K.; Belikov, A.; Blake, C.; Bout, J.; Boxhoorn, D.; Buddelmeijer, H.; Buddendiek, A.; Cacciato, M.; Capaccioli, M.; Choi, A.; Cordes, O.; Covone, G.; Dall'Ora, M.; Edge, A.; Erben, T.; Franse, J.; Getman, F.; Grado, A.; Harnois-Deraps, J.; Helmich, E.; Herbonnet, R.; Heymans, C.; Hildebrandt, H.; Hoekstra, H.; Huang, Z.; Irisarri, N.; Joachimi, B.; Köhlinger, F.; Kitching, T.; La Barbera, F.; Lacerda, P.; McFarland, J.; Miller, L.; Nakajima, R.; Napolitano, N. R.; Paolillo, M.; Peacock, J.; Pila-Diez, B.; Puddu, E.; Radovich, M.; Rifatto, A.; Schneider, P.; Schrabback, T.; Sifon, C.; Sikkema, G.; Simon, P.; Sutherland, W.; Tudorica, A.; Valentijn, E.; van der Burg, R.; van Uitert, E.; van Waerbeke, L.; Velander, M.; Kleijn, G. V.; Viola, M.; Vriend, W.-J.

2013-01-01

The Kilo-Degree Survey (KiDS), a 1500-square-degree optical imaging survey with the recently commissioned OmegaCAM wide-field imager on the VLT Survey Telescope (VST), is described. KiDS will image two fields in u-,g-,r- and i-bands and, together with the VIKING survey, produce nine-band (u- to

SETIBURST: A Robotic, Commensal, Realtime Multi-science Backend for the Arecibo Telescope

Energy Technology Data Exchange (ETDEWEB)

Chennamangalam, Jayanth; Karastergiou, Aris; Williams, Christopher [Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); MacMahon, David; Cobb, Jeff; Siemion, Andrew P. V.; Gajjar, Vishal; Werthimer, Dan [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720 (United States); Rajwade, Kaustubh; Lorimer, Duncan R.; McLaughlin, Maura A. [Department of Physics and Astronomy, West Virginia University, P.O. Box 6315, Morgantown, WV 26506 (United States); Armour, Wes, E-mail: jayanth@astro.ox.ac.uk [Oxford e-Research Centre, University of Oxford, Keble Road, Oxford OX1 3QG (United Kingdom)

2017-02-01

Radio astronomy has traditionally depended on observatories allocating time to observers for exclusive use of their telescopes. The disadvantage of this scheme is that the data thus collected is rarely used for other astronomy applications, and in many cases, is unsuitable. For example, properly calibrated pulsar search data can, with some reduction, be used for spectral line surveys. A backend that supports plugging in multiple applications to a telescope to perform commensal data analysis will vastly increase the science throughput of the facility. In this paper, we present “SETIBURST,” a robotic, commensal, realtime multi-science backend for the 305 m Arecibo Telescope. The system uses the 1.4 GHz, seven-beam Arecibo L -band Feed Array (ALFA) receiver whenever it is operated. SETIBURST currently supports two applications: SERENDIP VI, a SETI spectrometer that is conducting a search for signs of technological life, and ALFABURST, a fast transient search system that is conducting a survey of fast radio bursts (FRBs). Based on the FRB event rate and the expected usage of ALFA, we expect 0–5 FRB detections over the coming year. SETIBURST also provides the option of plugging in more applications. We outline the motivation for our instrumentation scheme and the scientific motivation of the two surveys, along with their descriptions and related discussions.

SETIBURST: A Robotic, Commensal, Realtime Multi-science Backend for the Arecibo Telescope

International Nuclear Information System (INIS)

Chennamangalam, Jayanth; Karastergiou, Aris; Williams, Christopher; MacMahon, David; Cobb, Jeff; Siemion, Andrew P. V.; Gajjar, Vishal; Werthimer, Dan; Rajwade, Kaustubh; Lorimer, Duncan R.; McLaughlin, Maura A.; Armour, Wes

2017-01-01

Radio astronomy has traditionally depended on observatories allocating time to observers for exclusive use of their telescopes. The disadvantage of this scheme is that the data thus collected is rarely used for other astronomy applications, and in many cases, is unsuitable. For example, properly calibrated pulsar search data can, with some reduction, be used for spectral line surveys. A backend that supports plugging in multiple applications to a telescope to perform commensal data analysis will vastly increase the science throughput of the facility. In this paper, we present “SETIBURST,” a robotic, commensal, realtime multi-science backend for the 305 m Arecibo Telescope. The system uses the 1.4 GHz, seven-beam Arecibo L -band Feed Array (ALFA) receiver whenever it is operated. SETIBURST currently supports two applications: SERENDIP VI, a SETI spectrometer that is conducting a search for signs of technological life, and ALFABURST, a fast transient search system that is conducting a survey of fast radio bursts (FRBs). Based on the FRB event rate and the expected usage of ALFA, we expect 0–5 FRB detections over the coming year. SETIBURST also provides the option of plugging in more applications. We outline the motivation for our instrumentation scheme and the scientific motivation of the two surveys, along with their descriptions and related discussions.

SETIBURST: A Robotic, Commensal, Realtime Multi-science Backend for the Arecibo Telescope

Science.gov (United States)

Chennamangalam, Jayanth; MacMahon, David; Cobb, Jeff; Karastergiou, Aris; Siemion, Andrew P. V.; Rajwade, Kaustubh; Armour, Wes; Gajjar, Vishal; Lorimer, Duncan R.; McLaughlin, Maura A.; Werthimer, Dan; Williams, Christopher

2017-02-01

Radio astronomy has traditionally depended on observatories allocating time to observers for exclusive use of their telescopes. The disadvantage of this scheme is that the data thus collected is rarely used for other astronomy applications, and in many cases, is unsuitable. For example, properly calibrated pulsar search data can, with some reduction, be used for spectral line surveys. A backend that supports plugging in multiple applications to a telescope to perform commensal data analysis will vastly increase the science throughput of the facility. In this paper, we present “SETIBURST,” a robotic, commensal, realtime multi-science backend for the 305 m Arecibo Telescope. The system uses the 1.4 GHz, seven-beam Arecibo L-band Feed Array (ALFA) receiver whenever it is operated. SETIBURST currently supports two applications: SERENDIP VI, a SETI spectrometer that is conducting a search for signs of technological life, and ALFABURST, a fast transient search system that is conducting a survey of fast radio bursts (FRBs). Based on the FRB event rate and the expected usage of ALFA, we expect 0-5 FRB detections over the coming year. SETIBURST also provides the option of plugging in more applications. We outline the motivation for our instrumentation scheme and the scientific motivation of the two surveys, along with their descriptions and related discussions.

The ROTSE-IIIa telescope system

International Nuclear Information System (INIS)

Smith, D.; Akerlof, C.; Kehoe, R.; McKay, T.; Rykoff, E.; Ashley, M.C.B.; Phillips, M.A.; Casperson, D.; Gisler, G.; McGowan, K.; Vestrand, W.T.; Wozniak, P.; Wren, J.; Marshall, S.

2003-01-01

We report on the current operating status of the ROTSE-IIIa telescope, currently undergoing testing at Los Alamos National Laboratories in New Mexico. It will be shipped to Siding Spring Observatory, Australia, in first quarter 2002. ROTSE-IIIa has been in automated observing mode since early October, 2001, after completing several weeks of calibration and check-out observations. Calibrated lists of objects in ROTSE-IIIa sky patrol data are produced routinely in an automated pipeline, and we are currently automating analysis procedures to compile these lists, eliminate false detections, and automatically identify transient and variable objects. The manual application of these procedures has already led to the detection of a nova that rose over six magnitudes in two days to a maximum detected brightness of mR ∼ 13.9 and then faded two magnitudes in two weeks. We also readily identify variable stars, includings those suspected to be variables from the Sloan Digital Sky Survey. We report on our system to allow public monitoring of the telescope operational status in real time over the WWW

WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope : The next generation wide-field spectroscopy facility for the William Herschel Telescope

NARCIS (Netherlands)

Dalton, Gavin; Trager, Scott C.; Abrams, Don Carlos; Carter, David; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.; MacIntosh, Mike; Evans, Chris; Lewis, Ian; Navarro, Ramon; Agocs, Tibor; Dee, Kevin; Rousset, Sophie; Tosh, Ian; Middleton, Kevin; Pragt, Johannes; Terrett, David; Brock, Matthew; Benn, Chris; Verheijen, Marc; Cano Infantes, Diego; Bevil, Craige; Steele, Iain; Mottram, Chris; Bates, Stuart; Gribbin, Francis J.; Rey, Jürg; Rodriguez, Luis Fernando; Delgado, Jose Miguel; Guinouard, Isabelle; Walton, Nic; Irwin, Michael J.; Jagourel, Pascal; Stuik, Remko; Gerlofsma, Gerrit; Roelfsma, Ronald; Skillen, Ian; Ridings, Andy; Balcells, Marc; Daban, Jean-Baptiste; Gouvret, Carole; Venema, Lars; Girard, Paul

We present the preliminary design of the WEAVE next generation spectroscopy facility for the William Herschel Telescope (WHT), principally targeting optical ground-based follow up of upcoming ground-based (LOFAR) and spacebased (Gaia) surveys. WEAVE is a multi-object and multi-IFU facility utilizing

Kalman Filter for Calibrating a Telescope Focal Plane

Science.gov (United States)

Kang, Bryan; Bayard, David

2006-01-01

The instrument-pointing frame (IPF) Kalman filter, and an algorithm that implements this filter, have been devised for calibrating the focal plane of a telescope. As used here, calibration signifies, more specifically, a combination of measurements and calculations directed toward ensuring accuracy in aiming the telescope and determining the locations of objects imaged in various arrays of photodetectors in instruments located on the focal plane. The IPF Kalman filter was originally intended for application to a spaceborne infrared astronomical telescope, but can also be applied to other spaceborne and ground-based telescopes. In the traditional approach to calibration of a telescope, (1) one team of experts concentrates on estimating parameters (e.g., pointing alignments and gyroscope drifts) that are classified as being of primarily an engineering nature, (2) another team of experts concentrates on estimating calibration parameters (e.g., plate scales and optical distortions) that are classified as being primarily of a scientific nature, and (3) the two teams repeatedly exchange data in an iterative process in which each team refines its estimates with the help of the data provided by the other team. This iterative process is inefficient and uneconomical because it is time-consuming and entails the maintenance of two survey teams and the development of computer programs specific to the requirements of each team. Moreover, theoretical analysis reveals that the engineering/ science iterative approach is not optimal in that it does not yield the best estimates of focal-plane parameters and, depending on the application, may not even enable convergence toward a set of estimates.

NASA's Newest Orbital Debris Ground-based Telescope Assets: MCAT and UKIRT

Science.gov (United States)

Lederer, S.; Frith, J.; Pace, L. F.; Cowardin, H. M.; Hickson, P.; Glesne, T.; Maeda, R.; Buckalew, B.; Nishimoto, D.; Douglas, D.; Stansbery, E. G.

2014-09-01

NASAs Orbital Debris Program Office (ODPO) will break ground on Ascension Island in 2014 to build the newest optical (0.30 1.06 microns) ground-based telescope asset dedicated to the study of orbital debris. The Meter Class Autonomous Telescope (MCAT) is a 1.3m optical telescope designed to track objects in orbits ranging from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO). Ascension Island is located in the South Atlantic Ocean, offering longitudinal sky coverage not afforded by the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) network. With a fast-tracking dome, a suite of visible wide-band filters, and a time-delay integration (TDI) capable camera, MCAT is capable of multiple observing modes ranging from tracking cataloged debris targets to surveying the overall debris environment. Access to the United Kingdom Infrared Telescope (UKIRT) will extend our spectral coverage into the near- (0.8-5 micron) and mid- to far-infrared (8-25 micron) regime. UKIRT is a 3.8m telescope located on Mauna Kea on the Big Island of Hawaii. At nearly 14,000-feet and above the atmospheric inversion layer, this is one of the premier astronomical sites in the world and is an ideal setting for an infrared telescope. An unprecedented one-third of this telescopes time has been allocated to collect orbital debris data for NASAs ODPO over a 2-year period. UKIRT has several instruments available to obtain low-resolution spectroscopy in both the near-IR and the mid/far-IR. Infrared spectroscopy is ideal for constraining the material types, albedos and sizes of debris targets, and potentially gaining insight into reddening effects caused by space weathering. In addition, UKIRT will be used to acquire broadband photometric imaging at GEO with the Wide Field Camera (WFCAM) for studying known objects of interest as well as collecting data in survey-mode to discover new targets. Results from the first stage of the debris campaign will be presented. The combination of

Optical instrumentation for science and formation flying with a starshade observatory

Science.gov (United States)

Martin, Stefan; Scharf, Daniel; Cady, Eric; Liebe, Carl; Tang, Hong

2015-09-01

In conjunction with a space telescope of modest size, a starshade enables observation of small exoplanets close to the parent star by blocking the direct starlight while the planet light remains unobscured. The starshade is flown some tens of thousands of kilometers ahead of the telescope. Science instruments may include a wide field camera for imaging the target exoplanetary system as well as an integral field spectrometer for characterization of exoplanet atmospheres. We show the preliminary designs of the optical instruments for observatories such as Exo-S, discuss formation flying and control, retargeting maneuvers and other aspects of a starshade mission. The implementation of a starshade-ready WFIRST-AFTA is discussed and we show how a compact, standalone instrument package could be developed as an add-on to future space telescopes, requiring only minor additions to the telescope spacecraft.

Ambitious Survey Spots Stellar Nurseries

Science.gov (United States)

2010-08-01

Astronomers scanning the skies as part of ESO's VISTA Magellanic Cloud survey have now obtained a spectacular picture of the Tarantula Nebula in our neighbouring galaxy, the Large Magellanic Cloud. This panoramic near-infrared view captures the nebula itself in great detail as well as the rich surrounding area of sky. The image was obtained at the start of a very ambitious survey of our neighbouring galaxies, the Magellanic Clouds, and their environment. The leader of the survey team, Maria-Rosa Cioni (University of Hertfordshire, UK) explains: "This view is of one of the most important regions of star formation in the local Universe - the spectacular 30 Doradus star-forming region, also called the Tarantula Nebula. At its core is a large cluster of stars called RMC 136, in which some of the most massive stars known are located." ESO's VISTA telescope [1] is a new survey telescope at the Paranal Observatory in Chile (eso0949). VISTA is equipped with a huge camera that detects light in the near-infrared part of the spectrum, revealing a wealth of detail about astronomical objects that gives us insight into the inner workings of astronomical phenomena. Near-infrared light has a longer wavelength than visible light and so we cannot see it directly for ourselves, but it can pass through much of the dust that would normally obscure our view. This makes it particularly useful for studying objects such as young stars that are still enshrouded in the gas and dust clouds from which they formed. Another powerful aspect of VISTA is the large area of the sky that its camera can capture in each shot. This image is the latest view from the VISTA Magellanic Cloud Survey (VMC). The project will scan a vast area - 184 square degrees of the sky (corresponding to almost one thousand times the apparent area of the full Moon) including our neighbouring galaxies the Large and Small Magellanic Clouds. The end result will be a detailed study of the star formation history and three

Using the Hobby-Eberly telescope to place constraints on planetary system formation

International Nuclear Information System (INIS)

Cochran, William D; Endl, Michael

2008-01-01

We are conducting several radial velocity surveys with the 9.2 m Hobby-Eberly telescope (HET). These surveys are designed to improve our understanding of the physics of planetary system formation and evolution. We present recent results from two of these HET surveys. The first is from our survey of metal-poor stars. This survey is designed to probe the physics of planet formation at low metallicities. We present the detection of two planetary companions to HD 155358, a star with [Fe/H] of -0.68. This is the lowest metallicity of any planet host star

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.

Using model based systems engineering for the development of the Large Synoptic Survey Telescope's operational plan

Science.gov (United States)

Selvy, Brian M.; Claver, Charles; Willman, Beth; Petravick, Don; Johnson, Margaret; Reil, Kevin; Marshall, Stuart; Thomas, Sandrine; Lotz, Paul; Schumacher, German; Lim, Kian-Tat; Jenness, Tim; Jacoby, Suzanne; Emmons, Ben; Axelrod, Tim

2016-08-01

We† provide an overview of the Model Based Systems Engineering (MBSE) language, tool, and methodology being used in our development of the Operational Plan for Large Synoptic Survey Telescope (LSST) operations. LSST's Systems Engineering (SE) team is using a model-based approach to operational plan development to: 1) capture the topdown stakeholders' needs and functional allocations defining the scope, required tasks, and personnel needed for operations, and 2) capture the bottom-up operations and maintenance activities required to conduct the LSST survey across its distributed operations sites for the full ten year survey duration. To accomplish these complimentary goals and ensure that they result in self-consistent results, we have developed a holistic approach using the Sparx Enterprise Architect modeling tool and Systems Modeling Language (SysML). This approach utilizes SysML Use Cases, Actors, associated relationships, and Activity Diagrams to document and refine all of the major operations and maintenance activities that will be required to successfully operate the observatory and meet stakeholder expectations. We have developed several customized extensions of the SysML language including the creation of a custom stereotyped Use Case element with unique tagged values, as well as unique association connectors and Actor stereotypes. We demonstrate this customized MBSE methodology enables us to define: 1) the rolls each human Actor must take on to successfully carry out the activities associated with the Use Cases; 2) the skills each Actor must possess; 3) the functional allocation of all required stakeholder activities and Use Cases to organizational entities tasked with carrying them out; and 4) the organization structure required to successfully execute the operational survey. Our approach allows for continual refinement utilizing the systems engineering spiral method to expose finer levels of detail as necessary. For example, the bottom-up, Use Case

The Lunar Transit Telescope (LTT) - An early lunar-based science and engineering mission

Science.gov (United States)

Mcgraw, John T.

1992-01-01

The Sentinel, the soft-landed lunar telescope of the LTT project, is described. The Sentinel is a two-meter telescope with virtually no moving parts which accomplishes an imaging survey of the sky over almost five octaves of the electromagnetic spectrum from the ultraviolet into the infrared, with an angular resolution better than 0.1 arsec/pixel. The Sentinel will incorporate innovative techniques of interest for future lunar-based telescopes and will return significant engineering data which can be incorporated into future lunar missions. The discussion covers thermal mapping of the Sentinel, measurement of the cosmic ray flux, lunar dust, micrometeoroid flux, the lunar atmosphere, and lunar regolith stability and seismic activity.

Origins Space Telescope: Breaking the Confusion Limit

Science.gov (United States)

Wright, Edward L.; Origins Space Telescope Science and Technology Definition Team

2018-01-01

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. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s.OST will have a background-limited sensitivity for a background 27,000 times lower than the Herschel background caused by thermal emission from Herschel's warm telescope. For continuum observations the confusion limit in a diffraction-limited survey can be reached in very short integration times at longer far-infrared wavelengths. But the confusion limit can be pierced for both the nearest and the farthest objects to be observed by OST. For outer the Solar System the targets' motion across the sky will provide a clear signature in surveys repeated after an interval of days to months. This will provide a size-frequency distribution of TNOs that is not biased toward high albedo objects.For the distant Universe the first galaxies and the first metals will provide a third dimension of spectral information that can be measured with a long-slit, medium resolution spectrograph. This will allow 3Dmapping to measure source densities as a function of redshift. The continuum shape associated with sourcesat different redshifts can be derived from correlation analyses of these 3D maps.Fairly large sky areas can be scanned by moving the spacecraft at a constant angular rate perpendicular to the orientation of the long slit of the spectrograph, avoiding the high overhead of step-and-stare surveying with a large space observatory.We welcome you to contact the Science and Technology Definition Team (STDT) with your science needs and ideas by emailing us at ost_info@lists.ipac.caltech.edu

The Southern HII Region Discovery Survey: The Bright Catalog

Science.gov (United States)

Wenger, Trey V.; Dickey, John M.; Jordan, Christopher H.; Balser, Dana; Armentrout, William Paul; Anderson, Loren; Bania, Thomas; Dawson, Joanne; McClure-Griffiths, Naomi M.; Shea, Jeanine

2018-01-01

HII regions, the zones of ionized gas surrounding recently formed high-mass stars, are the archetypical tracers of Galactic structure. The census of Galactic HII regions in the Southern sky is vastly incomplete due to a lack of sensitive radio recombination line (RRL) surveys. The Southern HII Region Discovery Survey (SHRDS) is a 900-hour Australia Telescope Compact Array cm-wavelength RRL and continuum emission survey of hundreds of third and fourth quadrant Galactic HII region candidates. These candidates are identified in the Widefield Infrared Survey Explorer (WISE) Catalog of Galactic HII Regions based on coincident 10 micron (WISE) and 20 cm (Southern Galactic Plane Survey) emission. The SHRDS is an extension of HII Region Discovery Surveys in the Northern sky with the Green Bank Telescope and Arecibo Telescope which discovered ~800 new HII regions. In the first 500 hours of the SHRDS, we targeted the 249 brightest HII region candidates and 33 previously known HII regions. We discuss the data reduction, analysis, and preliminary results from this first stage of the survey.

End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

Science.gov (United States)

Feinberg, Lee; Bolcar, Matt; Liu, Alice; Guyon, Olivier; Stark,Chris; Arenberg, Jon

2016-01-01

Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance.

The NASA/AFRL Meter Class Autonomous Telescope

Science.gov (United States)

Cowardin, H.; Lederer, S.; Buckalew, B.; Frith, J.; Hickson, P.; Glesne, T.; Anz-Meador, P.; Barker, E.; Stansbery, G.; Kervin, P.

2016-01-01

For the past decade, the NASA Orbital Debris Program Office (ODPO) has relied on using various ground-based telescopes in Chile to acquire statistical survey data as well as photometric and spectroscopic data of orbital debris in geosynchronous Earth orbit (GEO). The statistical survey data have been used to supply the Orbital Debris Engineering Model (ORDEM) v.3.0 with debris detections in GEO to better model the environment at altitudes where radar detections are limited. The data produced for the statistical survey ranged from 30 to 40 nights per year, which only accounted for 10% of the possible observing time. Data collection was restricted by ODPO resources and weather conditions. In order to improve the statistical sampling in GEO, as well as observe and sample other orbits, NASA's ODPO with support from the Air Force Research Laboratory (AFRL), has constructed a new observatory dedicated to orbital debris - the Meter Class Autonomous Telescope (MCAT) on Ascension Island. This location provides MCAT with the unique ability to access targets orbiting at an altitude of less than 1,000 km and low inclinations (< 20 deg). This orbital regime currently has little to no coverage by the U.S. Space Surveillance Network. Unlike previous ODPO optical assets, the ability to operate autonomously will allow rapid response observations of break-up events, an observing mode that was only available via radar tasking prior to MCAT's deployment. The primary goal of MCAT is to statistically characterize GEO via daily tasking files uploaded from ODPO. These tasking files define which operating mode to follow, providing the field center, rates, and/or targets to observe over the entire observing period. The system is also capable of tracking fast-moving targets in low Earth orbit (LEO), middle Earth orbit (MEO), as well as highly eccentric orbits like geostationary transfer orbits. On 25 August 2015, MCAT successfully acquired scientific first light, imaging the Bug Nebula and

The large binocular telescope.

Science.gov (United States)

Hill, John M

2010-06-01

The Large Binocular Telescope (LBT) Observatory is a collaboration among institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio, and Virginia. The telescope on Mount Graham in Southeastern Arizona uses two 8.4 m diameter primary mirrors mounted side by side. A unique feature of the LBT is that the light from the two Gregorian telescope sides can be combined to produce phased-array imaging of an extended field. This cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65 m aperture and a collecting area equivalent to an 11.8 m circular aperture. This paper describes the design, construction, and commissioning of this unique telescope. We report some sample astronomical results with the prime focus cameras. We comment on some of the technical challenges and solutions. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has completed final system testing in Firenze, Italy, and is planned to be at the telescope by Spring 2010.

SPHEREx: Probing the Physics of Inflation with an All-Sky Spectroscopic Galaxy Survey

Science.gov (United States)

Dore, Olivier; SPHEREx Science Team

2018-01-01

SPHEREx, a mission in NASA's Medium Explorer (MIDEX) program that was selected for Phase A in August 2017, is an all-sky survey satellite designed to address all three science goals in NASA’s astrophysics division: probe the origin and destiny of our Universe; explore whether planets around other stars could harbor life; and explore the origin and evolution of galaxies. These themes are addressed by a single survey, with a single instrument.In this poster, we describe how SPHEREx can probe the physics of inflationary non-Gaussianity by measuring large-scale structure with galaxy redshifts over a large cosmological volume at low redshifts, complementing high-redshift surveys optimized to constrain dark energy.SPHEREx will be the first all-sky near-infrared spectral survey, creating a legacy archive of spectra. In particular, it will measure the redshifts of over 500 million galaxies of all types, an unprecedented dataset. Using this catalog, SPHEREx will reduce the uncertainty in fNL -- a parameter describing the inflationary initial conditions -- by a factor of more than 10 compared with CMB measurements. At the same time, this catalog will enable strong scientific synergies with Euclid, WFIRST and LSST

The Hubble Space Telescope Medium Deep Survey Cluster Sample: Methodology and Data

Science.gov (United States)

Ostrander, E. J.; Nichol, R. C.; Ratnatunga, K. U.; Griffiths, R. E.

1998-12-01

We present a new, objectively selected, sample of galaxy overdensities detected in the Hubble Space Telescope Medium Deep Survey (MDS). These clusters/groups were found using an automated procedure that involved searching for statistically significant galaxy overdensities. The contrast of the clusters against the field galaxy population is increased when morphological data are used to search around bulge-dominated galaxies. In total, we present 92 overdensities above a probability threshold of 99.5%. We show, via extensive Monte Carlo simulations, that at least 60% of these overdensities are likely to be real clusters and groups and not random line-of-sight superpositions of galaxies. For each overdensity in the MDS cluster sample, we provide a richness and the average of the bulge-to-total ratio of galaxies within each system. This MDS cluster sample potentially contains some of the most distant clusters/groups ever detected, with about 25% of the overdensities having estimated redshifts z > ~0.9. We have made this sample publicly available to facilitate spectroscopic confirmation of these clusters and help more detailed studies of cluster and galaxy evolution. We also report the serendipitous discovery of a new cluster close on the sky to the rich optical cluster Cl l0016+16 at z = 0.546. This new overdensity, HST 001831+16208, may be coincident with both an X-ray source and a radio source. HST 001831+16208 is the third cluster/group discovered near to Cl 0016+16 and appears to strengthen the claims of Connolly et al. of superclustering at high redshift.

Engaging Undergraduate Students in Transiting Exoplanet Research with Small Telescopes

Science.gov (United States)

Stephens, Denise C.; Stoker, E.; Gaillard, C.; Ranquist, E.; Lara, P.; Wright, K.

2013-10-01

Brigham Young University has a relatively large undergraduate physics program with 300 to 360 physics majors. Each of these students is required to be engaged in a research group and to produce a senior thesis before graduating. For the astronomy professors, this means that each of us is mentoring at least 4-6 undergraduate students at any given time. For the past few years I have been searching for meaningful research projects that make use of our telescope resources and are exciting for both myself and my students. We first started following up Kepler Objects of Interest with our 0.9 meter telescope, but quickly realized that most of the transits we could observe were better analyzed with Kepler data and were false positive objects. So now we have joined a team that is searching for transiting planets, and my students are using our 16" telescope to do ground based follow-up on the hundreds of possible transiting planet candidates produced by this survey. In this presentation I will describe our current telescopes, the observational setup, and how we use our telescopes to search for transiting planets. I'll describe some of the software the students have written. I'll also explain how to use the NASA Exoplanet Archive to gather data on known transiting planets and Kepler Objects of Interests. These databases are useful for determining the observational limits of your small telescopes and teaching your students how to reduce and report data on transiting planets. Once that is in place, you are potentially ready to join existing transiting planet missions by doing ground-based follow-up. I will explain how easy it can be to implement this type of research at any high school, college, or university with a small telescope and CCD camera.

The Low-Resolution Spectrograph of the Hobby-Eberly Telescope. II. Observations of Quasar Candidates from the Sloan Digital Sky Survey

International Nuclear Information System (INIS)

Schneider, D. P.; Hill, Gary J.; Fan, X.; Ramsey, L. W.; MacQueen, P. J.; Weedman, D. W.; Booth, J. A.; Eracleous, M.; Gunn, J. E.; Lupton, R. H.

2000-01-01

This paper describes spectra of quasar candidates acquired during the commissioning phase of the Low-Resolution Spectrograph of the Hobby-Eberly Telescope. The objects were identified as possible quasars from multicolor image data from the Sloan Digital Sky Survey. The 10 sources had typical r' magnitudes of 19-20, except for one extremely red object with r ' ≅23. The data, obtained with exposure times between 10 and 25 minutes, reveal that the spectra of four candidates are essentially featureless and are not quasars, five are quasars with redshifts between 2.92 and 4.15 (including one broad absorption line quasar), and the red source is a very late M star or early L dwarf. (c) (c) 2000. The Astronomical Society of the Pacific

The VANDELS ESO spectroscopic survey

Science.gov (United States)

McLure, R. J.; Pentericci, L.; Cimatti, A.; Dunlop, J. S.; Elbaz, D.; Fontana, A.; Nandra, K.; Amorin, R.; Bolzonella, M.; Bongiorno, A.; Carnall, A. C.; Castellano, M.; Cirasuolo, M.; Cucciati, O.; Cullen, F.; De Barros, S.; Finkelstein, S. L.; Fontanot, F.; Franzetti, P.; Fumana, M.; Gargiulo, A.; Garilli, B.; Guaita, L.; Hartley, W. G.; Iovino, A.; Jarvis, M. J.; Juneau, S.; Karman, W.; Maccagni, D.; Marchi, F.; Mármol-Queraltó, E.; Pompei, E.; Pozzetti, L.; Scodeggio, M.; Sommariva, V.; Talia, M.; Almaini, O.; Balestra, I.; Bardelli, S.; Bell, E. F.; Bourne, N.; Bowler, R. A. A.; Brusa, M.; Buitrago, F.; Caputi, K. I.; Cassata, P.; Charlot, S.; Citro, A.; Cresci, G.; Cristiani, S.; Curtis-Lake, E.; Dickinson, M.; Fazio, G. G.; Ferguson, H. C.; Fiore, F.; Franco, M.; Fynbo, J. P. U.; Galametz, A.; Georgakakis, A.; Giavalisco, M.; Grazian, A.; Hathi, N. P.; Jung, I.; Kim, S.; Koekemoer, A. M.; Khusanova, Y.; Le Fèvre, O.; Lotz, J. M.; Mannucci, F.; Maltby, D. T.; Matsuoka, K.; McLeod, D. J.; Mendez-Hernandez, H.; Mendez-Abreu, J.; Mignoli, M.; Moresco, M.; Mortlock, A.; Nonino, M.; Pannella, M.; Papovich, C.; Popesso, P.; Rosario, D. P.; Salvato, M.; Santini, P.; Schaerer, D.; Schreiber, C.; Stark, D. P.; Tasca, L. A. M.; Thomas, R.; Treu, T.; Vanzella, E.; Wild, V.; Williams, C. C.; Zamorani, G.; Zucca, E.

2018-05-01

VANDELS is a uniquely-deep spectroscopic survey of high-redshift galaxies with the VIMOS spectrograph on ESO's Very Large Telescope (VLT). The survey has obtained ultra-deep optical (0.48 studies. Using integration times calculated to produce an approximately constant signal-to-noise ratio (20 motivation, survey design and target selection.

A 16-m Telescope for the Advanced Technology Large Aperture Telescope (ATLAST) Mission

Science.gov (United States)

Lillie, Charles F.; Dailey, D. R.; Polidan, R. S.

2010-01-01

Future space observatories will require increasingly large telescopes to study the earliest stars and galaxies, as well as faint nearby objects. Technologies now under development will enable telescopes much larger than the 6.5-meter diameter James Webb Space Telescope (JWST) to be developed at comparable costs. Current segmented mirror and deployable optics technology enables the 6.5 meter JWST telescope to be folded for launch in the 5-meter diameter Ariane 5 payload fairing, and deployed autonomously after reaching orbit. Late in the next decade, when the Ares V Cargo Launch Vehicle payload fairing becomes operational, even larger telescope can be placed in orbit. In this paper we present our concept for a 16-meter JWST derivative, chord-fold telescope which could be stowed in the 10-m diameter Ares V fairing, plus a description of the new technologies that enable ATLAST to be developed at an affordable price.

Cryogenic implications of orbit selection of the Space Infrared Telescope Facility (SIRTF)

International Nuclear Information System (INIS)

Lee, J.H.; Brooke, W.F.; Maa, S.

1986-01-01

The Infrared Astronomical Satellite (IRAS) which completed the first all sky survey in the infrared demonstrated the tremendous advantage of space-based infrared astronomy. The ability to cool the telescope optics and focal plane to liquid helium temperatures and the absence of atmospheric disturbances which cause ''seeing'' effects resulted in the discovery of 250,000 IR sources and many interesting phenomena including dust clouds around Vega and the infrared ''cirrus'' at 100 μm. To realize the true benefit of space infrared astronomy, NASA is now studying the Space Infrared Telescope Facility, a long-life space-based observatory, to follow up on the survey results of IRAS. The choice of orbits is a critical program decision. The objective of this paper is to compare the performance of an all superfluid helium SIRTF system in the two possible orbit inclinations, polar orbit (99 0 ) and the low inclination orbit (28.5 0 )

Operating performance of the gamma-ray Cherenkov telescope: An end-to-end Schwarzschild–Couder telescope prototype for the Cherenkov Telescope Array

Energy Technology Data Exchange (ETDEWEB)

Dournaux, J.L., E-mail: jean-laurent.dournaux@obspm.fr [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); De Franco, A. [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Laporte, P. [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); White, R. [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Greenshaw, T. [University of Liverpool, Oliver Lodge Laboratory, P.O. Box 147, Oxford Street, Liverpool L69 3BX (United Kingdom); Sol, H. [LUTH, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); Abchiche, A. [CNRS, Division technique DT-INSU, 1 Place Aristide Briand, 92190 Meudon (France); Allan, D. [Department of Physics and Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE (United Kingdom); Amans, J.P. [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); Armstrong, T.P. [Department of Physics and Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE (United Kingdom); Balzer, A.; Berge, D. [GRAPPA, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Boisson, C. [LUTH, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); and others

2017-02-11

The Cherenkov Telescope Array (CTA) consortium aims to build the next-generation ground-based very-high-energy gamma-ray observatory. The array will feature different sizes of telescopes allowing it to cover a wide gamma-ray energy band from about 20 GeV to above 100 TeV. The highest energies, above 5 TeV, will be covered by a large number of Small-Sized Telescopes (SSTs) with a field-of-view of around 9°. The Gamma-ray Cherenkov Telescope (GCT), based on Schwarzschild–Couder dual-mirror optics, is one of the three proposed SST designs. The GCT is described in this contribution and the first images of Cherenkov showers obtained using the telescope and its camera are presented. These were obtained in November 2015 in Meudon, France.

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

Design Considerations: Falcon M Dwarf Habitable Exoplanet Survey

Science.gov (United States)

Polsgrove, Daniel; Novotny, Steven; Della-Rose, Devin J.; Chun, Francis; Tippets, Roger; O'Shea, Patrick; Miller, Matthew

2016-01-01

The Falcon Telescope Network (FTN) is an assemblage of twelve automated 20-inch telescopes positioned around the globe, controlled from the Cadet Space Operations Center (CSOC) at the US Air Force Academy (USAFA) in Colorado Springs, Colorado. Five of the 12 sites are currently installed, with full operational capability expected by the end of 2016. Though optimized for studying near-earth objects to accomplish its primary mission of Space Situational Awareness (SSA), the Falcon telescopes are in many ways similar to those used by ongoing and planned exoplanet transit surveys targeting individual M dwarf stars (e.g., MEarth, APACHE, SPECULOOS). The network's worldwide geographic distribution provides additional potential advantages. We have performed analytical and empirical studies exploring the viability of employing the FTN for a future survey of nearby late-type M dwarfs tailored to detect transits of 1-2REarth exoplanets in habitable-zone orbits . We present empirical results on photometric precision derived from data collected with multiple Falcon telescopes on a set of nearby (survey design parameters is also described, including an analysis of site-specific weather data, anticipated telescope time allocation and the percentage of nearby M dwarfs with sufficient check stars within the Falcons' 11' x 11' field-of-view required to perform effective differential photometry. The results of this ongoing effort will inform the likelihood of discovering one (or more) habitable-zone exoplanets given current occurrence rate estimates over a nominal five-year campaign, and will dictate specific survey design features in preparation for initiating project execution when the FTN begins full-scale automated operations.

An innovative telescope control system architecture for SST-GATE telescopes at the CTA Observatory

Science.gov (United States)

Fasola, Gilles; Mignot, Shan; Laporte, Philippe; Abchiche, Abdel; Buchholtz, Gilles; Jégouzo, Isabelle

2014-07-01

SST-GATE (Small Size Telescope - GAmma-ray Telescope Elements) is a 4-metre telescope designed as a prototype for the Small Size Telescopes (SST) of the Cherenkov Telescope Array (CTA), a major facility for the very high energy gamma-ray astronomy of the next three decades. In this 100-telescope array there will be 70 SSTs, involving a design with an industrial view aiming at long-term service, low maintenance effort and reduced costs. More than a prototype, SST-GATE is also a fully functional telescope that shall be usable by scientists and students at the Observatoire de Meudon for 30 years. The Telescope Control System (TCS) is designed to work either as an element of a large array driven by an array controller or in a stand-alone mode with a remote workstation. Hence it is built to be autonomous with versatile interfacing; as an example, pointing and tracking —the main functions of the telescope— are managed onboard, including astronomical transformations, geometrical transformations (e.g. telescope bending model) and drive control. The core hardware is a CompactRIO (cRIO) featuring a real-time operating system and an FPGA. In this paper, we present an overview of the current status of the TCS. We especially focus on three items: the pointing computation implemented in the FPGA of the cRIO —using CORDIC algorithms— since it enables an optimisation of the hardware resources; data flow management based on OPCUA with its specific implementation on the cRIO; and the use of an EtherCAT field-bus for its ability to provide real-time data exchanges with the sensors and actuators distributed throughout the telescope.

Classic Telescopes A Guide to Collecting, Restoring, and Using Telescopes of Yesteryear

CERN Document Server

English, Neil

2013-01-01

Classic Telescopes explores the exciting world of telescopes past, as well as the possibilities involved in acquiring these instruments. What are classic telescopes? First, the book takes a look at the more traditional telescopes built by the great instrument makers of the eighteenth and nineteenth centuries and the dynastic houses founded by the likes of John Dollond, Alvan Clark, Thomas Cooke & Sons and Carl Zeiss, plus some lesser-known luminaries, including John Brashear, John Calver, and Henry Fitz. Instruments constructed from the 1950s until as recently as the early 1990s are now also considered 'classic.' There is thus a very active market for buying and selling these 'modern' classics. The author examines some of the most talked about instruments on the amateur Internet forums, including the Unitron refractors, the Questar 90, a classic 6-inch reflector, the RV-6; a 3-inch F/15 achromat by Fullerscopes; the time-honored AstroScan Richfield reflector; and many, many more. Classic telescopes are of...

Origins Space Telescope: Cosmology and Reionization

Science.gov (United States)

Vieira, Joaquin Daniel; Origins Space Telescope

2018-01-01

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. 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.A core science goal of the OST mission is to study the the cosmological history of star, galaxy, and structure formation into the epoch of reionization (EoR). OST will probe the birth of galaxies through warm molecular hydrogen emission during the cosmic dark ages. Utilizing the unique power of the infrared fine-structure emission lines, OST will trace the rise of metals from the first galaxies until today. It will quantify the dust enrichment history of the Universe, uncover its composition and physical conditions, reveal the first cosmic sources of dust, and probe the properties of the earliest star formation. OST will provide a detailed astrophysical probe into the condition of the intergalactic medium at z > 6 and the galaxies which dominate the epoch of reionization.

Alignment and phasing of deployable telescopes

Science.gov (United States)

Woolf, N. J.; Ulich, B. L.

1983-01-01

The experiences in coaligning and phasing the Multi-Mirror Telescope (MMT), together with studies in setting up radio telescopes, are presented. These experiences are discussed, and on the basis they furnish, schemes are suggested for coaligning and phasing four large future telescopes with complex primary mirror systems. These telescopes are MT2, a 15-m-equivalent MMT, the University of California Ten Meter Telescope, the 10 m sub-mm wave telescope of the University of Arizona and the Max Planck Institute for Radioastronomy, and the Large Deployable Reflector, a future space telescope for far-IR and sub-mm waves.

Focusing Cosmic Telescopes: Exploring Redshift z ~ 5-6 Galaxies with the Bullet Cluster 1E0657 - 56

Science.gov (United States)

Bradač, Maruša; Treu, Tommaso; Applegate, Douglas; Gonzalez, Anthony H.; Clowe, Douglas; Forman, William; Jones, Christine; Marshall, Phil; Schneider, Peter; Zaritsky, Dennis

2009-12-01

The gravitational potential of clusters of galaxies acts as a cosmic telescope allowing us to find and study galaxies at fainter limits than otherwise possible and thus probe closer to the epoch of formation of the first galaxies. We use the Bullet cluster 1E0657 - 56 (z = 0.296) as a case study, because its high mass and merging configuration makes it one of the most efficient cosmic telescopes we know. We develop a new algorithm to reconstruct the gravitational potential of the Bullet cluster based on a non-uniform adaptive grid, combining strong and weak gravitational lensing data derived from deep Hubble Space Telescope/Advanced Camera for Surveys F606W-F775W-F850LP and ground-based imaging. We exploit this improved mass map to study z ~ 5-6 Lyman break galaxies (LBGs), which we detect as dropouts. One of the LBGs is multiply imaged, providing a geometric confirmation of its high redshift, and is used to further improve our mass model. We quantify the uncertainties in the magnification map reconstruction in the intrinsic source luminosity, and in the volume surveyed, and show that they are negligible compared to sample variance when determining the luminosity function of high-redshift galaxies. With shallower and comparable magnitude limits to Hubble Ultra Deep Field (HUDF) and Great Observatories Origins Deep Survey (GOODS), the Bullet cluster observations, after correcting for magnification, probe deeper into the luminosity function of the high-redshift galaxies than GOODS and only slightly shallower than HUDF. We conclude that accurately focused cosmic telescopes are the most efficient way to sample the bright end of the luminosity function of high-redshift galaxies and—in case they are multiply imaged—confirm their redshifts. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5

OVERVIEW OF THE ATACAMA COSMOLOGY TELESCOPE: RECEIVER, INSTRUMENTATION, AND TELESCOPE SYSTEMS

International Nuclear Information System (INIS)

Swetz, D. S.; Devlin, M. J.; Dicker, S. R.; Ade, P. A. R.; Amiri, M.; Battistelli, E. S.; Burger, B.; Halpern, M.; Hasselfield, M.; Appel, J. W.; Essinger-Hileman, T.; Fisher, R. P.; Fowler, J. W.; Hincks, A. D.; Jarosik, N.; Chervenak, J.; Doriese, W. B.; Hilton, G. C.; Irwin, K. D.; Duenner, R.

2011-01-01

The Atacama Cosmology Telescope was designed to measure small-scale anisotropies in the cosmic microwave background and detect galaxy clusters through the Sunyaev-Zel'dovich effect. The instrument is located on Cerro Toco in the Atacama Desert, at an altitude of 5190 m. A 6 m off-axis Gregorian telescope feeds a new type of cryogenic receiver, the Millimeter Bolometer Array Camera. The receiver features three 1000-element arrays of transition-edge sensor bolometers for observations at 148 GHz, 218 GHz, and 277 GHz. Each detector array is fed by free space millimeter-wave optics. Each frequency band has a field of view of approximately 22' x 26'. The telescope was commissioned in 2007 and has completed its third year of operations. We discuss the major components of the telescope, camera, and related systems, and summarize the instrument performance.

Overview of the Atacama Cosmology Telescope: Receiver, Instrumentation, and Telescope Systems

Science.gov (United States)

Swetz, D. S.; Ade, P. A. R.; Amiri, M.; Appel, J. W.; Battistelli, E. S.; Burger, B.; Chervenak, J.; Devlin, M. J.; Dicker, S. R.; Doriese, W. B.; Dünner, R.; Essinger-Hileman, T.; Fisher, R. P.; Fowler, J. W.; Halpern, M.; Hasselfield, M.; Hilton, G. C.; Hincks, A. D.; Irwin, K. D.; Jarosik, N.; Kaul, M.; Klein, J.; Lau, J. M.; Limon, M.; Marriage, T. A.; Marsden, D.; Martocci, K.; Mauskopf, P.; Moseley, H.; Netterfield, C. B.; Niemack, M. D.; Nolta, M. R.; Page, L. A.; Parker, L.; Staggs, S. T.; Stryzak, O.; Switzer, E. R.; Thornton, R.; Tucker, C.; Wollack, E.; Zhao, Y.

2011-06-01

The Atacama Cosmology Telescope was designed to measure small-scale anisotropies in the cosmic microwave background and detect galaxy clusters through the Sunyaev-Zel'dovich effect. The instrument is located on Cerro Toco in the Atacama Desert, at an altitude of 5190 m. A 6 m off-axis Gregorian telescope feeds a new type of cryogenic receiver, the Millimeter Bolometer Array Camera. The receiver features three 1000-element arrays of transition-edge sensor bolometers for observations at 148 GHz, 218 GHz, and 277 GHz. Each detector array is fed by free space millimeter-wave optics. Each frequency band has a field of view of approximately 22' × 26'. The telescope was commissioned in 2007 and has completed its third year of operations. We discuss the major components of the telescope, camera, and related systems, and summarize the instrument performance.

The VANDELS ESO public spectroscopic survey

Science.gov (United States)

McLure, R. J.; Pentericci, L.; Cimatti, A.; Dunlop, J. S.; Elbaz, D.; Fontana, A.; Nandra, K.; Amorin, R.; Bolzonella, M.; Bongiorno, A.; Carnall, A. C.; Castellano, M.; Cirasuolo, M.; Cucciati, O.; Cullen, F.; De Barros, S.; Finkelstein, S. L.; Fontanot, F.; Franzetti, P.; Fumana, M.; Gargiulo, A.; Garilli, B.; Guaita, L.; Hartley, W. G.; Iovino, A.; Jarvis, M. J.; Juneau, S.; Karman, W.; Maccagni, D.; Marchi, F.; Mármol-Queraltó, E.; Pompei, E.; Pozzetti, L.; Scodeggio, M.; Sommariva, V.; Talia, M.; Almaini, O.; Balestra, I.; Bardelli, S.; Bell, E. F.; Bourne, N.; Bowler, R. A. A.; Brusa, M.; Buitrago, F.; Caputi, K. I.; Cassata, P.; Charlot, S.; Citro, A.; Cresci, G.; Cristiani, S.; Curtis-Lake, E.; Dickinson, M.; Fazio, G. G.; Ferguson, H. C.; Fiore, F.; Franco, M.; Fynbo, J. P. U.; Galametz, A.; Georgakakis, A.; Giavalisco, M.; Grazian, A.; Hathi, N. P.; Jung, I.; Kim, S.; Koekemoer, A. M.; Khusanova, Y.; Fèvre, O. Le; Lotz, J. M.; Mannucci, F.; Maltby, D. T.; Matsuoka, K.; McLeod, D. J.; Mendez-Hernandez, H.; Mendez-Abreu, J.; Mignoli, M.; Moresco, M.; Mortlock, A.; Nonino, M.; Pannella, M.; Papovich, C.; Popesso, P.; Rosario, D. P.; Salvato, M.; Santini, P.; Schaerer, D.; Schreiber, C.; Stark, D. P.; Tasca, L. A. M.; Thomas, R.; Treu, T.; Vanzella, E.; Wild, V.; Williams, C. C.; Zamorani, G.; Zucca, E.

2018-05-01

VANDELS is a uniquely-deep spectroscopic survey of high-redshift galaxies with the VIMOS spectrograph on ESO's Very Large Telescope (VLT). The survey has obtained ultra-deep optical (0.48 studies. Using integration times calculated to produce an approximately constant signal-to-noise ratio (20 motivation, survey design and target selection.

Alt-Az Spacewatch Telescope

Science.gov (United States)

Gehrels, Tom

1997-01-01

This grant funded about one third of the cost of the construction of a telescope with an aperture 1.8 meters in diameter to discover asteroids and comets and investigate the statistics of their populations and orbital distributions. This telescope has been built to the PI's specifications and installed in a dome on Kitt Peak mountain in Arizona. Funds for the dome and building were provided entirely by private sources. The dome building and telescope were dedicated in a ceremony at the site on June 7, 1997. The attached abstract describes the parameters of the telescope. The telescope is a new item of capital property. It is permanently located in University of Arizona building number 910 in the Steward Observatory compound on Kitt Peak mountain in the Tohono O'odham Nation, Arizona. fts property tag number is A252107. This grant did not include funds for the coma corrector lens, instrument derotator, CCD detector, detector electronics, or computers to acquire or process the data. It also did not include funds to operate the telescope or conduct research with it. Funds for these items and efforts are pending from NASA and other sources.

The VLA Sky Survey (VLASS): Description and Science Goals

Science.gov (United States)

Lacy, Mark; Baum, Stefi Alison; Chandler, Claire J.; Chatterjee, Shami; Murphy, Eric J.; Myers, Steven T.; VLASS Survey Science Group

2016-01-01

The VLA Sky Survey (VLASS) will cover 80% of the sky to a target depth of 70muJy in the 2-4GHz S-band of the Karl G. Jansky Very Large Array. With a resolution of 2.5 arcseconds, it will deliver the highest angular resolution of any wide area radio survey. Each area of the survey will be observed in three epochs spaced by 32 months in order to investigate the transient radio source population over an unprecedented combination of depth and area, resulting in a uniquely powerful search for hidden explosions in the Universe. The survey will be carried out in full polarization, allowing the characterization of the magneto-ionic medium in AGN and intervening galaxies over a wide range of redshifts, and the study of Faraday rotating foregrounds such as ionized bubbles in the Milky Way. The high angular resolution will allow us to make unambiguous identifications of nearly 10 million radio sources, comprised of both extragalactic objects and more nearby radio sources in the Milky Way, through matching to wide area optical/IR surveys such as SDSS, PanSTARRS, DES, LSST, EUCLID, WFIRST and WISE. Integral to the VLASS plan is an Education and Public Outreach component that will seek to inform and educate both the scientific community and the general public about radio astronomy through the use of social media, citizen science and educational activities. We will discuss opportunities for community involvement in VLASS, including the development of Enhanced Data Products and Services that will greatly increase the scientific utility of the survey.

Optical observations of LIGO source GW 170817 by the Antarctic Survey Telescopes at Dome A, Antarctica

Science.gov (United States)

Hu, Lei; Wu, Xuefeng; Andreoni, Igor; Ashley, Michael C. B.; Cooke, Jeff; Cui, Xiangqun; Du, Fujia; Dai, Zigao; Gu, Bozhong; Hu, Yi; Lu, Haiping; Li, Xiaoyan; Li, Zhengyang; Liang, Ensi; Liu, Liangduan; Ma, Bin; Shang, Zhaohui; Sun, Tianrui; Suntzeff, N. B.; Tao, Charling; Udden, Syed A.; Wang, Lifan; Wang, Xiaofeng; Wen, Haikun; Xiao, Di; Su, Jin; Yang, Ji; Yang, Shihai; Yuan, Xiangyan; Zhou, Hongyan; Zhang, Hui; Zhou, Jilin; Zhu, Zonghong

2017-10-01

The LIGO detection of gravitational waves (GW) from merging black holes in 2015 marked the beginning of a new era in observational astronomy. The detection of an electromagnetic signal from a GW source is the critical next step to explore in detail the physics involved. The Antarctic Survey Telescopes (AST3), located at Dome A, Antarctica, is uniquely situated for rapid response time-domain astronomy with its continuous night-time coverage during the austral winter. We report optical observations of the GW source (GW 170817) in the nearby galaxy NGC 4993 using AST3. The data show a rapidly fading transient at around 1 day after the GW trigger, with the i-band magnitude declining from 17.23±0.13 magnitude to 17.72±0.09 magnitude in ˜ 0.8 hour. The brightness and time evolution of the optical transient associated with GW 170817 are broadly consistent with the predictions of models involving merging binary neutron stars. We infer from our data that the merging process ejected about ˜ 10^{-2} solar mass of radioactive material at a speed of up to 30% the speed of light.

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.

Discovering Interacting Binaries with Halpha Surveys

NARCIS (Netherlands)

Witham, A.; Knigge, C.; Drew, J.; Groot, P.J.; Greimel, R.; Parker, Q.

2005-01-01

A deep (R ~ 19.5) photographic Halpha Survey of the southern Galactic Plane was recently completed using the UK Schmidt Telescope at the AAO. In addition, we have recently started a similar, CCD-based survey of the northern Galactic Plane using the Wide Field Camera on the INT. Both surveys aim to

Statistics, data mining, and machine learning in astronomy a practical Python guide for the analysis of survey data

CERN Document Server

Ivezic, Željko; VanderPlas, Jacob T; Gray, Alexander

2014-01-01

As telescopes, detectors, and computers grow ever more powerful, the volume of data at the disposal of astronomers and astrophysicists will enter the petabyte domain, providing accurate measurements for billions of celestial objects. This book provides a comprehensive and accessible introduction to the cutting-edge statistical methods needed to efficiently analyze complex data sets from astronomical surveys such as the Panoramic Survey Telescope and Rapid Response System, the Dark Energy Survey, and the upcoming Large Synoptic Survey Telescope. It serves as a practical handbook for graduate s

Scientific Performance Analysis of the SYZ Telescope Design versus the RC Telescope Design

Science.gov (United States)

Ma, Donglin; Cai, Zheng

2018-02-01

Recently, Su et al. propose an innovative design, referred as the “SYZ” design, for China’s new project of a 12 m optical-infrared telescope. The SYZ telescope design consists of three aspheric mirrors with non-zero power, including a relay mirror below the primary mirror. SYZ design yields a good imaging quality and has a relatively flat field curvature at Nasmyth focus. To evaluate the science-compatibility of this three-mirror telescope, in this paper, we thoroughly compare the performance of SYZ design with that of Ritchey–Chrétien (RC) design, a conventional two-mirror telescope design. Further, we propose the Observing Information Throughput (OIT) as a metric for quantitatively evaluating the telescopes’ science performance. We find that although a SYZ telescope yields a superb imaging quality over a large field of view, a two-mirror (RC) telescope design holds a higher overall throughput, a better diffraction-limited imaging quality in the central field of view (FOV < 5‧) which is better for the performance of extreme Adaptive Optics (AO), and a generally better scientific performance with a higher OIT value. D. Ma & Z. Cai contributed equally to this paper.

An afocal telescope configuration for the ESA Ariel mission

Science.gov (United States)

Da Deppo, V.; Middleton, K.; Focardi, M.; Morgante, G.; Pace, E.; Claudi, R.; Micela, G.

2017-09-01

ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is one of the three candidates for the next ESA medium-class science mission (M4) expected to be launched in 2026. This mission will be devoted to observing spectroscopically in the infrared (IR) a large population of known transiting planets in the neighborhood of the Solar System, opening a new discovery space in the field of extrasolar planets and enabling the understanding of the physics and chemistry of these far away worlds. ARIEL is based on a 1-m class telescope ahead of two spectrometer channels covering the band 1.95 to 7.8 microns. In addition there are four photometric channels: two wide band, also used as fine guidance sensors, and two narrow band. During its 3.5 years of operations from L2 orbit, ARIEL will continuously observe exoplanets transiting their host star. The ARIEL optical design is conceived as a fore-module common afocal telescope that will feed the spectrometer and photometric channels. The telescope optical design is composed of an off-axis portion of a two-mirror classic Cassegrain coupled to a tertiary off-axis paraboloidal mirror. The telescope and optical bench operating temperatures, as well as those of some subsystems, will be monitored and fine tuned/stabilised mainly by means of a thermal control subsystem (TCU-Telescope Control Unit) working in closed-loop feedback and hosted by the main Payload electronics unit, the Instrument Control Unit (ICU). Another important function of the TCU will be to monitor the telescope and optical bench thermistors when the Payload decontamination heaters will be switched on (when operating the instrument in Decontamination Mode) during the Commissioning Phase and cyclically, if required. Then the thermistors data will be sent by the ICU to the On Board Computer by means of a proper formatted telemetry. The latter (OBC) will be in charge of switching on and off the decontamination heaters on the basis of the thermistors readout

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

Science.gov (United States)

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.

2006-06-01

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-mechanical control of the telescope. The VST is a single instrument telescope. This placed stringent reliability requirements on the OmegaCAM detector system such as 10 years lifetime and maximum downtime of 1.5 %. Mounting at Cassegrain focus required a highly autonomous self-contained cooling system that could deliver 65 W of cooling power. Interface space for the detector head was severely limited by the way the instrument encloses the CCD cryostat. The detector system features several novel ideas tailored to meet these requirements and described in this paper: Key design drivers of the detector head were the easily separable but precisely aligned connections to the optical field flattener on the top and the cooling system at the bottom. Material selection, surface treatment, specialized coatings and in-situ plasma cleaning were crucial to prevent contamination of the detectors. Inside the cryostat, cryogenic and electrical connections were disentangled to keep the configuration modular, integration friendly and the detectors in a safe condition during all mounting steps. A compact unit for logging up to 125 Pt100 temperature sensors and associated thermal control loops was developed (ESO's new housekeeping unit PULPO 2), together with several new modular Pt100 packaging and mounting concepts. The electrical grouping of CCDs based on process parameters and test results is explained. Three ESO standardized FIERA CCD controllers in different configurations are used. Their synchronization mechanism for read-out is discussed in connection with the CCD grouping scheme, the shutter, and the integrated guiding and image analysis facility with four independent 2K x 4K CCDs. An

Linear feature detection algorithm for astronomical surveys - II. Defocusing effects on meteor tracks

Science.gov (United States)

Bektešević, Dino; Vinković, Dejan; Rasmussen, Andrew; Ivezić, Željko

2018-03-01

Given the current limited knowledge of meteor plasma micro-physics and its interaction with the surrounding atmosphere and ionosphere, meteors are a highly interesting observational target for high-resolution wide-field astronomical surveys. Such surveys are capable of resolving the physical size of meteor plasma heads, but they produce large volumes of images that need to be automatically inspected for possible existence of long linear features produced by meteors. Here, we show how big aperture sky survey telescopes detect meteors as defocused tracks with a central brightness depression. We derive an analytic expression for a defocused point source meteor track and use it to calculate brightness profiles of meteors modelled as uniform brightness discs. We apply our modelling to meteor images as seen by the Sloan Digital Sky Survey and Large Synoptic Survey Telescope telescopes. The expression is validated by Monte Carlo ray-tracing simulations of photons travelling through the atmosphere and the Large Synoptic Survey Telescope telescope optics. We show that estimates of the meteor distance and size can be extracted from the measured full width at half-maximum and the strength of the central dip in the observed brightness profile. However, this extraction becomes difficult when the defocused meteor track is distorted by the atmospheric seeing or contaminated by a long-lasting glowing meteor trail. The full width at half-maximum of satellite tracks is distinctly narrower than meteor values, which enables removal of a possible confusion between satellites and meteors.

The Pan-STARRS1 Surveys

Science.gov (United States)

Chambers, Kenneth; Pan-STARRS Team

2018-01-01

The Pan-STARRS1 Surveys are complete and the first data release, DR1, is available from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The data include a database of measured attributes of 3 billion objects, stacked images, and metadata of the 3pi Steradian Survey. The DR1 contains all stationary objects with mean and stack photometry registered on the GAIA astrometric frame. DR2 is in preparation and will be released this winter with all the individual epoch images and time domain photometry and forced photometry on the individual epoch images. The characteristics of the Pan-STARRS1 Surveys will be presented, including image quality, depth, cadence, and coverage. Measured attributes include PSF model magnitudes, aperture magnitudes, Kron Magnitudes, radial moments, Petrosian magnitudes, DeVaucoulers, Exponential, and Sersic magnitudes for extended objects. Images include total intensity, variance, and masks.An overview of the Pan-STARRS1 Surveys and data releases will be presented together with a brief description of the data collected since the end of the PS1 Science Consortium surveys, and the plans for the upcoming survey with PS1 and PS2 begining in February 2018.

Exoplanet Biosignatures: Observational Prospects

Science.gov (United States)

Angerhausen, Daniel; Deitrick, Russell; Domagal-Goldman, Shawn; Grenfell, John Lee; Hori, Yasunori; Kane, Stephen R.; Pallé, Enric; Rauer, Heike; Siegler, Nicholas; Stapelfeldt, Karl; Stevenson, Kevin B.

2018-01-01

Abstract Exoplanet hunting efforts have revealed the prevalence of exotic worlds with diverse properties, including Earth-sized bodies, which has fueled our endeavor to search for life beyond the Solar System. Accumulating experiences in astrophysical, chemical, and climatological characterization of uninhabitable planets are paving the way to characterization of potentially habitable planets. In this paper, we review our possibilities and limitations in characterizing temperate terrestrial planets with future observational capabilities through the 2030s and beyond, as a basis of a broad range of discussions on how to advance “astrobiology” with exoplanets. We discuss the observability of not only the proposed biosignature candidates themselves but also of more general planetary properties that provide circumstantial evidence, since the evaluation of any biosignature candidate relies on its context. Characterization of temperate Earth-sized planets in the coming years will focus on those around nearby late-type stars. The James Webb Space Telescope (JWST) and later 30-meter-class ground-based telescopes will empower their chemical investigations. Spectroscopic studies of potentially habitable planets around solar-type stars will likely require a designated spacecraft mission for direct imaging, leveraging technologies that are already being developed and tested as part of the Wide Field InfraRed Survey Telescope (WFIRST) mission. Successful initial characterization of a few nearby targets will be an important touchstone toward a more detailed scrutiny and a larger survey that are envisioned beyond 2030. The broad outlook this paper presents may help develop new observational techniques to detect relevant features as well as frameworks to diagnose planets based on the observables. Key Words: Exoplanets—Biosignatures—Characterization—Planetary atmospheres—Planetary surfaces. Astrobiology 18, 739–778. PMID:29938537

Evidence of a Non-universal Stellar Initial Mass Function. Insights from HST Optical Imaging of Six Ultra-faint Dwarf Milky Way Satellites

Science.gov (United States)

Gennaro, Mario; Tchernyshyov, Kirill; Brown, Thomas M.; Geha, Marla; Avila, Roberto J.; Guhathakurta, Puragra; Kalirai, Jason S.; Kirby, Evan N.; Renzini, Alvio; Simon, Joshua D.; Tumlinson, Jason; Vargas, Luis C.

2018-03-01

Using deep observations obtained with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST), we demonstrate that the sub-solar stellar initial mass function (IMF) of six ultra-faint dwarf Milky Way satellites (UFDs) is more bottom light than the IMF of the Milky Way disk. Our data have a lower-mass limit of ∼0.45 M ⊙, while the upper limit is ∼0.8 M ⊙, set by the turnoff mass of these old, metal-poor systems. If formulated as a single power law, we obtain a shallower IMF slope than the Salpeter value of ‑2.3, ranging from ‑1.01 for Leo IV to ‑1.87 for Boötes I. The significance of these deviations depends on the galaxy and is typically 95% or more. When modeled as a log-normal, the IMF fit results in a higher peak mass than in the Milky Way disk, but a Milky Way disk value for the characteristic system mass (∼0.22 M ⊙) is excluded at only 68% significance, and only for some UFDs in the sample. We find that the IMF slope correlates well with the galaxy mean metallicity, and to a lesser degree, with the velocity dispersion and the total mass. The strength of the observed correlations is limited by shot noise in the number of observed stars, but future space-based missions like the James Webb Space Telescope (JWST) and the Wide-Field Infrared Survey Telescope ( WFIRST) will enhance both the number of dwarf Milky Way satellites that can be studied in such detail and the observation depth for individual galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-12549.

Simulations of cm-wavelength Sunyaev-Zel'dovich galaxy cluster and point source blind sky surveys and predictions for the RT32/OCRA-f and the Hevelius 100-m radio telescope

Energy Technology Data Exchange (ETDEWEB)

Lew, Bartosz; Kus, Andrzej [Toruń Centre for Astronomy, Nicolaus Copernicus University, ul. Gagarina 11, 87-100 Toruń (Poland); Birkinshaw, Mark [HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Wilkinson, Peter, E-mail: blew@astro.uni.torun.pl, E-mail: Mark.Birkinshaw@bristol.ac.uk, E-mail: peter.wilkinson@manchester.ac.uk, E-mail: ajk@astro.uni.torun.pl [Jodrell Bank Centre for Astrophysics, The University of Manchester, Alan Turing Building, Manchester M13 9PL (United Kingdom)

2015-02-01

We investigate the effectiveness of blind surveys for radio sources and galaxy cluster thermal Sunyaev-Zel'dovich effects (TSZEs) using the four-pair, beam-switched OCRA-f radiometer on the 32-m radio telescope in Poland. The predictions are based on mock maps that include the cosmic microwave background, TSZEs from hydrodynamical simulations of large scale structure formation, and unresolved radio sources. We validate the mock maps against observational data, and examine the limitations imposed by simplified physics. We estimate the effects of source clustering towards galaxy clusters from NVSS source counts around Planck-selected cluster candidates, and include appropriate correlations in our mock maps. The study allows us to quantify the effects of halo line-of-sight alignments, source confusion, and telescope angular resolution on the detections of TSZEs. We perform a similar analysis for the planned 100-m Hevelius radio telescope (RTH) equipped with a 49-beam radio camera and operating at frequencies up to 22 GHz.We find that RT32/OCRA-f will be suitable for small-field blind radio source surveys, and will detect 33{sup +17}{sub −11} new radio sources brighter than 0.87 mJy at 30 GHz in a 1 deg{sup 2} field at > 5σ CL during a one-year, non-continuous, observing campaign, taking account of Polish weather conditions. It is unlikely that any galaxy cluster will be detected at 3σ CL in such a survey. A 60-deg{sup 2} survey, with field coverage of 2{sup 2} beams per pixel, at 15 GHz with the RTH, would find <1.5 galaxy clusters per year brighter than 60 μJy (at 3σ CL), and would detect about 3.4 × 10{sup 4} point sources brighter than 1 mJy at 5σ CL, with confusion causing flux density errors ∼< 2% (20%) in 68% (95%) of the detected sources.A primary goal of the planned RTH will be a wide-area (π sr) radio source survey at 15 GHz. This survey will detect nearly 3 × 10{sup 5} radio sources at 5σ CL down to 1.3 mJy, and tens of galaxy

Goddard's Astrophysics Science Divsion Annual Report 2014

Science.gov (United States)

Weaver, Kimberly (Editor); Reddy, Francis (Editor); Tyler, Pat (Editor)

2015-01-01

) Explorer mission, in collaboration with MIT (Ricker, PI); the Soft X-ray Spectrometer (SXS) for the Astro-H mission in collaboration with JAXA, and the James Webb Space Telescope (JWST). The Wide-Field Infrared Survey Telescope (WFIRST), the highest ranked mission in the 2010 decadal survey, is in a pre-phase A study, and we are supplying study scientists for that mission.

Virtual Telescope Alignment System

Data.gov (United States)

National Aeronautics and Space Administration — Next-generation space telescopes require two spacecraft to fly in a coordinated fashion in space forming a virtual telescope. Achieving and maintaining this precise...

THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS. III. A QUINTUPLE STELLAR POPULATION IN NGC 2808

International Nuclear Information System (INIS)

Milone, A. P.; Marino, A. F.; Jerjen, H.; Piotto, G.; Renzini, A.; Bedin, L. R.; Anderson, J.; Bellini, A.; Cassisi, S.; Pietrinferni, A.; D’Antona, F.; Ventura, P.

2015-01-01

In this study we present the first results from multi-wavelength Hubble Space Telescope (HST) observations of the Galactic globular cluster (GC) NGC 2808 as an extension of the Hubble Space Telescope UV Legacy Survey of Galactic GCs (GO-13297 and previous proprietary and HST archive data). Our analysis allowed us to disclose a multiple-stellar-population phenomenon in NGC 2808 even more complex than previously thought. We have separated at least five different populations along the main sequence and the red giant branch (RGB), which we name A, B, C, D, and E (though an even finer subdivision may be suggested by the data). We identified the RGB bump in four out of the five RGBs. To explore the origin of this complex color–magnitude diagram, we have combined our multi-wavelength HST photometry with synthetic spectra, generated by assuming different chemical compositions. The comparison of observed colors with synthetic spectra suggests that the five stellar populations have different contents of light elements and helium. Specifically, if we assume that NGC 2808 is homogeneous in [Fe/H] (as suggested by spectroscopy for Populations B, C, D, E, but lacking for Population A) and that population A has a primordial helium abundance, we find that populations B, C, D, E are enhanced in helium by ΔY ∼ 0.03, 0.03, 0.08, 0.13, respectively. We obtain similar results by comparing the magnitude of the RGB bumps with models. Planned spectroscopic observations will test whether Population A also has the same metallicity, or whether its photometric differences with Population B can be ascribed to small [Fe/H] and [O/H] differences rather than to helium

Sloan Digital Sky Survey Photometric Calibration Revisited

International Nuclear Information System (INIS)

Marriner, John

2012-01-01

The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

Sloan Digital Sky Survey Photometric Calibration Revisited

Energy Technology Data Exchange (ETDEWEB)

Marriner, John; /Fermilab

2012-06-29

The Sloan Digital Sky Survey calibration is revisited to obtain the most accurate photometric calibration. A small but significant error is found in the flat-fielding of the Photometric telescope used for calibration. Two SDSS star catalogs are compared and the average difference in magnitude as a function of right ascension and declination exhibits small systematic errors in relative calibration. The photometric transformation from the SDSS Photometric Telescope to the 2.5 m telescope is recomputed and compared to synthetic magnitudes computed from measured filter bandpasses.

James Webb Space Telescope Optical Telescope Element Mirror Development History and Results

Science.gov (United States)

Feinber, Lee D.; Clampin, Mark; Keski-Kuha, Ritva; Atkinson, Charlie; Texter, Scott; Bergeland, Mark; Gallagher, Benjamin B.

2012-01-01

In a little under a decade, the James Webb Space Telescope (JWST) program has designed, manufactured, assembled and tested 21 flight beryllium mirrors for the James Webb Space Telescope Optical Telescope Element. This paper will summarize the mirror development history starting with the selection of beryllium as the mirror material and ending with the final test results. It will provide an overview of the technological roadmap and schedules and the key challenges that were overcome. It will also provide a summary or the key tests that were performed and the results of these tests.

The STAR-X X-Ray Telescope Assembly (XTA)

Science.gov (United States)

McClelland, Ryan S.; Bautz, Mark W.; Bonafede, Joseph A.; Miller, Eric D.; Saha, Timo T.; Solly, Peter M.; Zhang, William W.

2017-01-01

The Survey and Time-domain Astrophysical Research eXplorer (STAR-X) science goals are to discover what powers the most violent explosions in the Universe, understand how black holes grow across cosmic time and mass scale, and measure how structure formation heats the majority of baryons in the Universe. To achieve these goals, STAR-X requires a powerful X-ray telescope with a large field of view, large collecting area, and excellent point spread function. The STAR-X instrument, the X-Ray Telescope Assembly (XTA), meets these requirements using a powerful X-ray mirror technology based on precision-polished single crystal silicon and a mature CCD detector technology. The XTA is composed of three major subsystems: an X-ray Mirror Assembly (MA) of high resolution, lightweight mirror segments fabricated out of single crystal silicon; a Focal Plane Assembly (FPA) made of back-illuminated CCD's capable of detecting X-rays with excellent quantum efficiency; and a composite Telescope Tube that structurally links the MA and FPA. The MA consists of 5,972 silicon mirror segments mounted into five subassemblies called meta-shells. A meta-shell is constructed from an annular central structural shell covered with interlocking layers of mirror segments. This paper describes the requirements, design, and analysis of the XTA subsystems with particular focus on the MA.

Swift Burst Alert Telescope (BAT) Instrument Response

International Nuclear Information System (INIS)

Parsons, A.; Barthelmy, S.; Cummings, J.; Gehrels, N.; Hullinger, D.; Krimm, H.; Markwardt, C.; Tueller, J.; Fenimore, E.; Palmer, D.; Sato, G.; Takahashi, T.; Nakazawa, K.; Okada, Y.; Takahashi, H.; Suzuki, M.; Tashiro, M.

2004-01-01

The Burst Alert Telescope (BAT), a large coded aperture instrument with a wide field-of-view (FOV), provides the gamma-ray burst triggers and locations for the Swift Gamma-Ray Burst Explorer. In addition to providing this imaging information, BAT will perform a 15 keV - 150 keV all-sky hard x-ray survey based on the serendipitous pointings resulting from the study of gamma-ray bursts, and will also monitor the sky for transient hard x-ray sources. For BAT to provide spectral and photometric information for the gamma-ray bursts, the transient sources and the all-sky survey, the BAT instrument response must be determined to an increasingly greater accuracy. This paper describes the spectral models and the ground calibration experiments used to determine the BAT response to an accuracy suitable for gamma-ray burst studies

Wide Field Radio Transient Surveys

Science.gov (United States)

Bower, Geoffrey

2011-04-01

The time domain of the radio wavelength sky has been only sparsely explored. Nevertheless, serendipitous discovery and results from limited surveys indicate that there is much to be found on timescales from nanoseconds to years and at wavelengths from meters to millimeters. These observations have revealed unexpected phenomena such as rotating radio transients and coherent pulses from brown dwarfs. Additionally, archival studies have revealed an unknown class of radio transients without radio, optical, or high-energy hosts. The new generation of centimeter-wave radio telescopes such as the Allen Telescope Array (ATA) will exploit wide fields of view and flexible digital signal processing to systematically explore radio transient parameter space, as well as lay the scientific and technical foundation for the Square Kilometer Array. Known unknowns that will be the target of future transient surveys include orphan gamma-ray burst afterglows, radio supernovae, tidally-disrupted stars, flare stars, and magnetars. While probing the variable sky, these surveys will also provide unprecedented information on the static radio sky. I will present results from three large ATA surveys (the Fly's Eye survey, the ATA Twenty CM Survey (ATATS), and the Pi GHz Survey (PiGSS)) and several small ATA transient searches. Finally, I will discuss the landscape and opportunities for future instruments at centimeter wavelengths.

Near-Earth Object Survey Simulation Software

Science.gov (United States)

Naidu, Shantanu P.; Chesley, Steven R.; Farnocchia, Davide

2017-10-01

There is a significant interest in Near-Earth objects (NEOs) because they pose an impact threat to Earth, offer valuable scientific information, and are potential targets for robotic and human exploration. The number of NEO discoveries has been rising rapidly over the last two decades with over 1800 being discovered last year, making the total number of known NEOs >16000. Pan-STARRS and the Catalina Sky Survey are currently the most prolific NEO surveys, having discovered >1600 NEOs between them in 2016. As next generation surveys such as Large Synoptic Survey Telescope (LSST) and the proposed Near-Earth Object Camera (NEOCam) become operational in the next decade, the discovery rate is expected to increase tremendously. Coordination between various survey telescopes will be necessary in order to optimize NEO discoveries and create a unified global NEO discovery network. We are collaborating on a community-based, open-source software project to simulate asteroid surveys to facilitate such coordination and develop strategies for improving discovery efficiency. Our effort so far has focused on development of a fast and efficient tool capable of accepting user-defined asteroid population models and telescope parameters such as a list of pointing angles and camera field-of-view, and generating an output list of detectable asteroids. The software takes advantage of the widely used and tested SPICE library and architecture developed by NASA’s Navigation and Ancillary Information Facility (Acton, 1996) for saving and retrieving asteroid trajectories and camera pointing. Orbit propagation is done using OpenOrb (Granvik et al. 2009) but future versions will allow the user to plug in a propagator of their choice. The software allows the simulation of both ground-based and space-based surveys. Performance is being tested using the Grav et al. (2011) asteroid population model and the LSST simulated survey “enigma_1189”.

Pulsar searches of Fermi unassociated sources with the Effelsberg telescope

International Nuclear Information System (INIS)

Barr, E. D.; Guillemot, L.; Champion, D. J.; Kramer, M.; Eatough, R. P.

2012-01-01

Using the 100-m Effelsberg radio telescope operating at 1.36 GHz, we have performed a targeted radio pulsar survey of 289 unassociated γ-ray sources discovered by the Large Area Telescope (LAT) aboard the Fermi satellite and published in the 1FGL catalogue (Abdo et al. 2010a). In addition, this survey resulted in the discovery of millisecond pulsar J1745+1017, which resides in a short-period binary system with a low-mass companion, M c,min ~0.0137M⊙, indicative of ‘black widow’ type systems. A 2-yr timing campaign has produced a refined radio ephemeris, accurate enough to allow for phase-folding of the LAT photons, resulting in the detection of a dual-peaked γ-ray light curve, proving that PSR J1745+1017 is the source responsible for the γ-ray emission seen in 1FGL J1745.5+1018 (2FGL J1745.6+1015; Nolan et al. 2012). We find the γ-ray spectrum of PSR J1745+1017 to be well modelled by an exponentially cut-off power law with cut-off energy 3.2 GeV and photon index 1.6. The observed sources are known to contain a further 10 newly discovered pulsars which were undetected in this survey. Our radio observations of these sources are discussed and in all cases limiting flux densities are calculated. Lastly, the reasons behind the seemingly low yield of discoveries are also discussed.

Photochemical Haze Formation in the Atmospheres of Super-Earths and Mini-Neptunes

Science.gov (United States)

He, Chao; Hoerst, Sarah M.; Lewis, Nikole K.; Yu, Xinting; Moses, Julianne I.; Kempton, Eliza M.- R.; Marley, Mark S.; McGuiggan, Patricia; Morley, Caroline V.; Valenti, Jeff A.;

Unveiling the Low Surface Brightness Stellar Peripheries of Galaxies

Science.gov (United States)

Ferguson, Annette M. N.

2018-01-01

The low surface brightness peripheral regions of galaxies contain a gold mine of information about how minor mergers and accretions have influenced their evolution over cosmic time. Enormous stellar envelopes and copious amounts of faint tidal debris are natural outcomes of the hierarchical assembly process and the search for and study of these features, albeit highly challenging, offers the potential for unrivalled insight into the mechanisms of galaxy growth. Over the last two decades, there has been burgeoning interest in probing galaxy outskirts using resolved stellar populations. Wide-field surveys have uncovered vast tidal debris features and new populations of very remote globular clusters, while deep Hubble Space Telescope photometry has provided exquisite star formation histories back to the earliest epochs. I will highlight some recent results from studies within and beyond the Local Group and conclude by briefly discussing the great potential of future facilities, such as JWST, Euclid, LSST and WFIRST, for major breakthroughs in low surface brightness galaxy periphery science.

Mechanical design of SST-GATE, a dual-mirror telescope for the Cherenkov Telescope Array

Science.gov (United States)

Dournaux, Jean-Laurent; Huet, Jean-Michel; Amans, Jean-Philippe; Dumas, Delphine; Laporte, Philippe; Sol, Hélène; Blake, Simon

2014-07-01

The Cherenkov Telescope Array (CTA) project aims to create the next generation Very High Energy (VHE) gamma-ray telescope array. It will be devoted to the observation of gamma rays over a wide band of energy, from a few tens of GeV to more than 100 TeV. Two sites are foreseen to view the whole sky where about 100 telescopes, composed of three different classes, related to the specific energy region to be investigated, will be installed. Among these, the Small Size class of Telescopes, SSTs, are devoted to the highest energy region, to beyond 100 TeV. Due to the large number of SSTs, their unit cost is an important parameter. At the Observatoire de Paris, we have designed a prototype of a Small Size Telescope named SST-GATE, based on the dual-mirror Schwarzschild-Couder optical formula, which has never before been implemented in the design of a telescope. Over the last two years, we developed a mechanical design for SST-GATE from the optical and preliminary mechanical designs made by the University of Durham. The integration of this telescope is currently in progress. Since the early stages of mechanical design of SST-GATE, finite element method has been used employing shape and topology optimization techniques to help design several elements of the telescope. This allowed optimization of the mechanical stiffness/mass ratio, leading to a lightweight and less expensive mechanical structure. These techniques and the resulting mechanical design are detailed in this paper. We will also describe the finite element analyses carried out to calculate the mechanical deformations and the stresses in the structure under observing and survival conditions.

Supernovae Discovery Efficiency

Science.gov (United States)

John, Colin

2018-01-01

Abstract:We present supernovae (SN) search efficiency measurements for recent Hubble Space Telescope (HST) surveys. Efficiency is a key component to any search, and is important parameter as a correction factor for SN rates. To achieve an accurate value for efficiency, many supernovae need to be discoverable in surveys. This cannot be achieved from real SN only, due to their scarcity, so fake SN are planted. These fake supernovae—with a goal of realism in mind—yield an understanding of efficiency based on position related to other celestial objects, and brightness. To improve realism, we built a more accurate model of supernovae using a point-spread function. The next improvement to realism is planting these objects close to galaxies and of various parameters of brightness, magnitude, local galactic brightness and redshift. Once these are planted, a very accurate SN is visible and discoverable by the searcher. It is very important to find factors that affect this discovery efficiency. Exploring the factors that effect detection yields a more accurate correction factor. Further inquires into efficiency give us a better understanding of image processing, searching techniques and survey strategies, and result in an overall higher likelihood to find these events in future surveys with Hubble, James Webb, and WFIRST telescopes. After efficiency is discovered and refined with many unique surveys, it factors into measurements of SN rates versus redshift. By comparing SN rates vs redshift against the star formation rate we can test models to determine how long star systems take from the point of inception to explosion (delay time distribution). This delay time distribution is compared to SN progenitors models to get an accurate idea of what these stars were like before their deaths.

HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

International Nuclear Information System (INIS)

Schneider, Adam C.; Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R.; Mace, Gregory N.; Wright, Edward L.; Eisenhardt, Peter R.; Skrutskie, M. F.; Griffith, Roger L.; Marsh, Kenneth A.

2015-01-01

We present a sample of brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE) for which we have obtained Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (22 in total) was observed with the G141 grism covering 1.10–1.70 μm, while 15 were also observed with the G102 grism, which covers 0.90–1.10 μm. The additional wavelength coverage provided by the G102 grism allows us to (1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.,ammonia bands) and (2) construct a smooth spectral sequence across the T/Y boundary. We find no evidence of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35+280548.5 (Y0.5), WISE J120604.38+840110.6 (Y0), and WISE J235402.77+024015.0 (Y1), are the 19th, 20th, and 21st spectroscopically confirmed Y dwarfs to date. We also present HST grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments

HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER

Energy Technology Data Exchange (ETDEWEB)

Schneider, Adam C.; Cushing, Michael C. [Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606 (United States); Kirkpatrick, J. Davy; Gelino, Christopher R. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Mace, Gregory N.; Wright, Edward L. [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Eisenhardt, Peter R. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Skrutskie, M. F. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Griffith, Roger L. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Marsh, Kenneth A., E-mail: Adam.Schneider@Utoledo.edu [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom)

2015-05-10

We present a sample of brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE) for which we have obtained Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) near-infrared grism spectroscopy. The sample (22 in total) was observed with the G141 grism covering 1.10–1.70 μm, while 15 were also observed with the G102 grism, which covers 0.90–1.10 μm. The additional wavelength coverage provided by the G102 grism allows us to (1) search for spectroscopic features predicted to emerge at low effective temperatures (e.g.,ammonia bands) and (2) construct a smooth spectral sequence across the T/Y boundary. We find no evidence of absorption due to ammonia in the G102 spectra. Six of these brown dwarfs are new discoveries, three of which are found to have spectral types of T8 or T9. The remaining three, WISE J082507.35+280548.5 (Y0.5), WISE J120604.38+840110.6 (Y0), and WISE J235402.77+024015.0 (Y1), are the 19th, 20th, and 21st spectroscopically confirmed Y dwarfs to date. We also present HST grism spectroscopy and reevaluate the spectral types of five brown dwarfs for which spectral types have been determined previously using other instruments.

Evaluating SLOOH Robotic Telescopes for Formal Educational Use

Science.gov (United States)

Gershun, D.; Berryhill, K. J.; Slater, T. F.

2012-12-01

The past several years has seen a gradual shift from telescopes being used only by top researchers to a case where educators across the STEM spectrum now have access to quality telescopes. This has been made possible by equipping telescopes to be controlled over the internet, either robotically which requires no human interaction during observation, or remotely which retain full user controllability. Education researchers around the world have recently focused on applications in elementary and secondary education (McKinnon & Geissinger 2002, Sadler et al. 2007). Responding to this paradigm shift, graduate students and faculty at the University of Wyoming and Center for Physic & Astronomy Education Research (www.caperteam.com) are dedicating time to explore this further at the undergraduate level, in order to better advise STEM educators of the most effective technological resources and curriculum development. Current research focuses on evaluating the academic merit of using SLOOH Space Camera in a summer online course offered by the University of Wyoming Outreach Program. SLOOH has robotic telescopes in the Canary Islands and La Dehesa, Chile. This evaluation will provide valuable data on an emerging technology as well as serve to advise future introductory astronomy sections at the University of Wyoming on the use of similar internet-controlled telescopes. The eight-week course exposed nine graduate science education students to basic night sky observing knowledge as well as provided hands-on experience using several robotic and remote observatories1,2,3,4. This mixed-methods case study collected data in the forms of six focus-group recordings, pre- and post-tests from all participants, a post-class survey, and general observations by the lead researcher. Transcripts and comments are coded to determine the most important features of SLOOH, and testing measures are analyzed to gauge the incoming and outgoing knowledge of participants. Analysis of testing measures

Hunting for Supermassive Black Holes in Nearby Galaxies With the Hobby-Eberly Telescope

Science.gov (United States)

van den Bosch, Remco C. E.; Gebhardt, Karl; Gültekin, Kayhan; Yıldırım, Akin; Walsh, Jonelle L.

2015-05-01

We have conducted an optical long-slit spectroscopic survey of 1022 galaxies using the 10 m Hobby-Eberly Telescope (HET) at McDonald Observatory. The main goal of the HET Massive Galaxy Survey (HETMGS) is to find nearby galaxies that are suitable for black hole mass measurements. In order to measure accurately the black hole mass, one should kinematically resolve the region where the black hole dominates the gravitational potential. For most galaxies, this region is much less than an arcsecond. Thus, black hole masses are best measured in nearby galaxies with telescopes that obtain high spatial resolution. The HETMGS focuses on those galaxies predicted to have the largest sphere-of-influence, based on published stellar velocity dispersions or the galaxy fundamental plane. To ensure coverage over galaxy types, the survey targets those galaxies across a face-on projection of the fundamental plane. We present the sample selection and resulting data products from the long-slit observations, including central stellar kinematics and emission line ratios. The full data set, including spectra and resolved kinematics, is available online. Additionally, we show that the current crop of black hole masses are highly biased toward dense galaxies and that especially large disks and low dispersion galaxies are under-represented. This survey provides the necessary groundwork for future systematic black hole mass measurement campaigns.

HUNTING FOR SUPERMASSIVE BLACK HOLES IN NEARBY GALAXIES WITH THE HOBBY–EBERLY TELESCOPE

International Nuclear Information System (INIS)

Bosch, Remco C. E. van den; Yıldırım, Akin; Gebhardt, Karl; Walsh, Jonelle L.; Gültekin, Kayhan

2015-01-01

We have conducted an optical long-slit spectroscopic survey of 1022 galaxies using the 10 m Hobby–Eberly Telescope (HET) at McDonald Observatory. The main goal of the HET Massive Galaxy Survey (HETMGS) is to find nearby galaxies that are suitable for black hole mass measurements. In order to measure accurately the black hole mass, one should kinematically resolve the region where the black hole dominates the gravitational potential. For most galaxies, this region is much less than an arcsecond. Thus, black hole masses are best measured in nearby galaxies with telescopes that obtain high spatial resolution. The HETMGS focuses on those galaxies predicted to have the largest sphere-of-influence, based on published stellar velocity dispersions or the galaxy fundamental plane. To ensure coverage over galaxy types, the survey targets those galaxies across a face-on projection of the fundamental plane. We present the sample selection and resulting data products from the long-slit observations, including central stellar kinematics and emission line ratios. The full data set, including spectra and resolved kinematics, is available online. Additionally, we show that the current crop of black hole masses are highly biased toward dense galaxies and that especially large disks and low dispersion galaxies are under-represented. This survey provides the necessary groundwork for future systematic black hole mass measurement campaigns

The Southern HII Region Discovery Survey

Science.gov (United States)

Wenger, Trey; Miller Dickey, John; Jordan, Christopher; Bania, Thomas M.; Balser, Dana S.; Dawson, Joanne; Anderson, Loren D.; Armentrout, William P.; McClure-Griffiths, Naomi

2016-01-01

HII regions are zones of ionized gas surrounding recently formed high-mass (OB-type) stars. They are among the brightest objects in the sky at radio wavelengths. HII regions provide a useful tool in constraining the Galactic morphological structure, chemical structure, and star formation rate. We describe the Southern HII Region Discovery Survey (SHRDS), an Australia Telescope Compact Array (ATCA) survey that discovered ~80 new HII regions (so far) in the Galactic longitude range 230 degrees to 360 degrees. This project is an extension of the Green Bank Telescope HII Region Discovery Survey (GBT HRDS), Arecibo HRDS, and GBT Widefield Infrared Survey Explorer (WISE) HRDS, which together discovered ~800 new HII regions in the Galactic longitude range -20 degrees to 270 degrees. Similar to those surveys, candidate HII regions were chosen from 20 micron emission (from WISE) coincident with 10 micron (WISE) and 20 cm (SGPS) emission. By using the ATCA to detect radio continuum and radio recombination line emission from a subset of these candidates, we have added to the population of known Galactic HII regions.

The BUFFALO HST Survey

Science.gov (United States)

Steinhardt, Charles; Jauzac, Mathilde; Capak, Peter; Koekemoer, Anton; Oesch, Pascal; Richard, Johan; Sharon, Keren q.; BUFFALO

2018-01-01

Beyond Ultra-deep Frontier Fields And Legacy Observations (BUFFALO) is an astronomical survey built around the six Hubble Space Telescope (HST) Frontier Fields clusters designed to learn about early galactic assembly and clustering and prepare targets for observations with the James Webb Space Telescope. BUFFALO will place significant new constraints on how and when the most massive and luminous galaxies in the universe formed and how early galaxy formation is linked to dark matter assembly. The same data will also probe the temperature and cross section of dark matter in the massive Frontier Fields galaxy clusters, and tell us how the dark matter, cluster gas, and dynamics of the clusters influence the galaxies in and around them. These studies are possible because the Spitzer Space Telescope, Chandra X-ray Observatory, XMM-Newton, and ground based telescopes have already invested heavily in deep observations around the Frontier Fields, so that the addition of HST observations can yield significant new results.

Science Flight Program of the Nuclear Compton Telescope

Science.gov (United States)

Boggs, Steven

This is the lead proposal for this program. We are proposing a 5-year program to perform the scientific flight program of the Nuclear Compton Telescope (NCT), consisting of a series of three (3) scientific balloon flights. NCT is a balloon-borne, wide-field telescope designed to survey the gamma-ray sky (0.2-5 MeV), performing high-resolution spectroscopy, wide-field imaging, and polarization measurements. NCT has been rebuilt as a ULDB payload under the current 2-year APRA grant. (In that proposal we stated our goal was to return at this point to propose the scientific flight program.) The NCT rebuild/upgrade is on budget and schedule to achieve flight-ready status in Fall 2013. Science: NCT will map the Galactic positron annihilation emission, shedding more light on the mysterious concentration of this emission uncovered by INTEGRAL. NCT will survey Galactic nucleosynthesis and the role of supernova and other stellar populations in the creation and evolution of the elements. NCT will map 26-Al and positron annihilation with unprecedented sensitivity and uniform exposure, perform the first mapping of 60-Fe, search for young, hidden supernova remnants through 44-Ti emission, and enable a host of other nuclear astrophysics studies. NCT will also study compact objects (in our Galaxy and AGN) and GRBs, providing novel measurements of polarization as well as detailed spectra and light curves. Design: NCT is an array of germanium gamma-ray detectors configured in a compact, wide-field Compton telescope configuration. The array is shielded on the sides and bottom by an active anticoincidence shield but is open to the 25% of the sky above for imaging, spectroscopy, and polarization measurements. The instrument is mounted on a zenith-pointed gondola, sweeping out ~50% of the sky each day. This instrument builds off the Compton telescope technique pioneered by COMPTEL on the Compton Gamma Ray Observatory. However, by utilizing modern germanium semiconductor strip detectors

THE ALL-SKY GEOS RR Lyr SURVEY WITH THE TAROT TELESCOPES: ANALYSIS OF THE BLAZHKO EFFECT

International Nuclear Information System (INIS)

Le Borgne, J.-F.; Klotz, A.; Poretti, E.; Boër, M.; Butterworth, N.; Dvorak, S.; Dumont, M.; Hambsch, F.-J.; Vandenbroere, J.; Hund, F.; Kugel, F.; Vilalta, J. M.

2012-01-01

We used the GEOS database to study the Blazhko effect of galactic RRab stars. The database is continuously enriched by maxima supplied by amateur astronomers and by a dedicated survey by means of the two TAROT robotic telescopes. The same value of the Blazhko period is observed at different values of the pulsation periods and different values of the Blazhko periods are observed at the same value of the pulsation period. There are clues suggesting that the Blazhko effect is changing from one cycle to the next. The secular changes in the pulsation and Blazhko periods of Z CVn are anticorrelated. The diagrams of magnitudes against phases of the maxima clearly show that the light curves of Blazhko variables can be explained as modulated signals, both in amplitude and in frequency. The closed curves describing the Blazhko cycles in such diagrams have different shapes, reflecting the phase shifts between the epochs of the brightest maximum and the maximum O – C. Our sample shows that both clockwise and counterclockwise directions are possible for similar shapes. The improved observational knowledge of the Blazhko effect, in addition to some peculiarities of the light curves, has yet to be explained by a satisfactory physical mechanism.

THE ALL-SKY GEOS RR Lyr SURVEY WITH THE TAROT TELESCOPES: ANALYSIS OF THE BLAZHKO EFFECT

Energy Technology Data Exchange (ETDEWEB)

Le Borgne, J.-F.; Klotz, A.; Poretti, E. [Universite de Toulouse, UPS-OMP, IRAP, 31400 Toulouse (France); Boeer, M. [ARTEMIS, Universite Nice Sophia-Antipolis, CNRS, Observatoire de la Cote d' Azur, Nice (France); Butterworth, N.; Dvorak, S. [American Association of Variable Star Observers (AAVSO), 49 Bay State Rd., Cambridge, MA 02138 (United States); Dumont, M.; Hambsch, F.-J.; Vandenbroere, J. [Groupe Europeen d' Observations Stellaires (GEOS), 23 Parc de Levesville, 28300 Bailleau l' Eveque (France); Hund, F. [Bundesdeutsche Arbeitsgemeinschaft fuer Veraenderliche Sterne e.V. (BAV), Munsterdamm 90, 12169 Berlin (Germany); Kugel, F. [Observatoire Chante-Perdrix, 04150 Banon (France); Vilalta, J. M. [Agrupacio Astronomica de Sabadell (AAS), Apartat de Correus, 50, 08200 Sabadell, Barcelona (Spain)

2012-08-15

We used the GEOS database to study the Blazhko effect of galactic RRab stars. The database is continuously enriched by maxima supplied by amateur astronomers and by a dedicated survey by means of the two TAROT robotic telescopes. The same value of the Blazhko period is observed at different values of the pulsation periods and different values of the Blazhko periods are observed at the same value of the pulsation period. There are clues suggesting that the Blazhko effect is changing from one cycle to the next. The secular changes in the pulsation and Blazhko periods of Z CVn are anticorrelated. The diagrams of magnitudes against phases of the maxima clearly show that the light curves of Blazhko variables can be explained as modulated signals, both in amplitude and in frequency. The closed curves describing the Blazhko cycles in such diagrams have different shapes, reflecting the phase shifts between the epochs of the brightest maximum and the maximum O - C. Our sample shows that both clockwise and counterclockwise directions are possible for similar shapes. The improved observational knowledge of the Blazhko effect, in addition to some peculiarities of the light curves, has yet to be explained by a satisfactory physical mechanism.

Active optics and modified-Rumsey wide-field telescopes: MINITRUST demonstrators with vase- and tulip-form mirrors

Science.gov (United States)

Lemaître, Gérard R.; Montiel, Pierre; Joulié, Patrice; Dohlen, Kjetil; Lanzoni, Patrick

2005-12-01

Wide-field astronomy requires the development of larger aperture telescopes. The optical properties of a three-mirror modified-Rumsey design provide significant advantages when compared to other telescope designs: (i) at any wavelength, the design has a flat field and is anastigmatic; (ii) the system is extremely compact, i.e., it is almost four times shorter than a Schmidt. Compared to the equally compact flat-field Ritchey-Chrétien with a doublet-lens corrector, as developed for the Sloan digital sky survey - and which requires the polishing of six optical surfaces - the proposed modified-Rumsey design requires only a two-surface polishing and provides a better imaging quality. All the mirrors are spheroids of the hyperboloid type. Starting from the classical Rumsey design, it is shown that the use of all eight available free parameters allows the simultaneous aspherization of the primary and tertiary mirrors by active optics methods from a single deformable substrate. The continuity conditions between the primary and the tertiary hyperbolizations are achieved by an intermediate narrow ring of constant thickness that is not optically used. After the polishing of a double vase form in a spherical shape, the primary-tertiary hyperbolizations are achieved by in situ stressing. The tulip-form secondary is hyperbolized by stress polishing. Other active optics alternatives are possible for a space telescope. The modified-Rumsey design is of interest for developing large space- and ground-based survey telescopes in UV, visible, or IR ranges, such as currently demonstrated with the construction of identical telescopes MINITRUST-1 and -2, f/5 - 2° field of view. Double-pass optical tests show diffraction-limited images.

The first telescope of the HEGRA air Cherenkov imaging telescope array

International Nuclear Information System (INIS)

Mirzoyan, R.; Kankanian, R.; Krennrich, F.; Mueller, N.; Sander, H.; Sawallisch, P.; Aharonian, F.; Akhperjanian, A.; Beglarian, A.; Fernandez, J.; Fonseca, V.; Grewe, W.; Heusler, A.; Konopelko, A.K.; Lorenz, E.; Merck, M.; Plyasheshnikov, A.V.; Renker, D.; Samorski, M.; Sauerland, K.; Smarsch, E.; Stamm, W.; Ulrich, M.; Wiedner, C.A.; Wirth, H.

1994-01-01

In search of VHE γ ray emission from cosmic point sources a system of imaging Cherenkov telescopes is constructed at present on the Canarian island of La Palma; the first telescope has been operational since 1992. The Cherenkov light from air shower particles is collected by a 5 m 2 reflector. The camera at the focus contains 37 photomultipliers which sample the images of the Cherenkov flashes. The subsequent image analysis allows the discrimination of γ ray induced events from the much more abundant charged cosmic ray induced showers. The telescope has an effective energy threshold for γ showers of about 1.5 TeV. During the first year of operation a signal from the Crab nebula was detected. ((orig.))

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".

Spectroscopic surveys of LAMOST

International Nuclear Information System (INIS)

Zhao Yongheng

2015-01-01

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), a new type of reflecting Schmidt telescope, has been designed and produced in China. It marks a breakthrough for large scale spectroscopic survey observation in that both large aperture and wide field of view have been achieved. LAMOST has the highest spectrum acquisition rate, and from October 2011 to June 2014 it has obtained 4.13 million spectra of celestial objects, of which 3.78 million are spectra of stars, with the stellar parameters of 2.20 million stars included. (author)

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...

Deploying the NASA Meter Class Autonomous Telescope (MCAT) on Ascension Island

Science.gov (United States)

Lederer, S. M.; Pace, L.; Hickson, P.; Cowardin, H. M.; Frith, J.; Buckalew, B.; Glesne, T.; Maeda, R.; Douglas, D.; Nishimoto, D.

2015-01-01

NASA has successfully constructed the 1.3m Meter Class Autonomous Telescope (MCAT) facility on Ascension Island in the South Atlantic Ocean. MCAT is an optical telescope designed specifically to collect ground-based data for the statistical characterization of orbital debris ranging from Low Earth Orbit (LEO) through Middle Earth Orbits (MEO) and beyond to Geo Transfer and Geosynchronous Orbits (GTO/GEO). The location of Ascension Island has two distinct advantages. First, the near-equatorial location fills a significant longitudinal gap in the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) network of telescopes, and second, it allows access to objects in Low Inclination Low-Earth Orbits (LILO). The MCAT facility will be controlled by a sophisticated software suite that operates the dome and telescope, assesses sky and weather conditions, conducts all necessary calibrations, defines an observing strategy (as dictated by weather, sky conditions and the observing plan for the night), and carries out the observations. It then reduces the collected data via four primary observing modes ranging from tracking previously cataloged objects to conducting general surveys for detecting uncorrelated debris. Nightly observing plans, as well as the resulting text file of reduced data, will be transferred to and from Ascension, respectively, via a satellite connection. Post-processing occurs at NASA Johnson Space Center. Construction began in September, 2014 with dome and telescope installation occurring in April through early June, 2015. First light was achieved in June, 2015. Acceptance testing, full commissioning, and calibration of this soon-to-be fully autonomous system commenced in summer 2015. The initial characterization of the system from these tests is presented herein.

End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

Science.gov (United States)

Feinberg, Lee; Rioux, Norman; Bolcar, Matthew; Liu, Alice; Guyon, Oliver; Stark, Chris; Arenberg, Jon

2016-01-01

Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and Exo-Earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling it.

Thick silicon microstrip detectors simulation for PACT: Pair and Compton Telescope

Science.gov (United States)

Khalil, M.; Laurent, P.; Lebrun, F.; Tatischeff, V.; Dolgorouky, Y.; Bertoli, W.; Breelle, E.

2016-11-01

PACT is a space borne Pair and Compton Telescope that aims to make a sensitive survey of the gamma-ray sky between 100 keV and 100 MeV. It is based upon two main components: a silicon-based gamma-ray tracker and a crystal-based calorimeter. In this paper we will explain the imaging technique of PACT as a Multi-layered Compton telescope (0.1-10 MeV) and its major improvements over its predecessor COMPTEL. Then we will present a simulation study to optimize the silicon tracker of PACT. This tracker is formed of thousands of identical silicon double sided strip detectors (DSSDs). We have developed a simulation model (using SILVACO) to simulate the DSSD performance while varying its thickness, impurity concentration of the bulk material, electrode pitch, and electrode width. We will present a comprehensive overview of the impact of each varied parameter on the DSSD performance, in view of the application to PACT. The considered DSSD parameters are its depletion voltage, capacitance, and leakage current. After the selection of the PACT DSSD, we will present a simulation of the performance of the PACT telescope in the 0.1-10 MeV range.

Thick silicon microstrip detectors simulation for PACT: Pair and Compton Telescope

International Nuclear Information System (INIS)

Khalil, M.; Laurent, P.; Lebrun, F.; Tatischeff, V.; Dolgorouky, Y.; Bertoli, W.; Breelle, E.

2016-01-01

PACT is a space borne Pair and Compton Telescope that aims to make a sensitive survey of the gamma-ray sky between 100 keV and 100 MeV. It is based upon two main components: a silicon-based gamma-ray tracker and a crystal-based calorimeter. In this paper we will explain the imaging technique of PACT as a Multi-layered Compton telescope (0.1–10 MeV) and its major improvements over its predecessor COMPTEL. Then we will present a simulation study to optimize the silicon tracker of PACT. This tracker is formed of thousands of identical silicon double sided strip detectors (DSSDs). We have developed a simulation model (using SILVACO) to simulate the DSSD performance while varying its thickness, impurity concentration of the bulk material, electrode pitch, and electrode width. We will present a comprehensive overview of the impact of each varied parameter on the DSSD performance, in view of the application to PACT. The considered DSSD parameters are its depletion voltage, capacitance, and leakage current. After the selection of the PACT DSSD, we will present a simulation of the performance of the PACT telescope in the 0.1–10 MeV range.

Thick silicon microstrip detectors simulation for PACT: Pair and Compton Telescope

Energy Technology Data Exchange (ETDEWEB)

Khalil, M., E-mail: khalilmohammad@hotmail.com [APC Laboratory, 10rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); Laurent, P.; Lebrun, F. [APC Laboratory, 10rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); CEA, Centre de Saclay, 91191 Gif-Sur-Yvette Cedex (France); Tatischeff, V. [CSNSM, IN2P3/CNRSand Paris-Sud University, 91405 Orsay Campus (France); Dolgorouky, Y.; Bertoli, W.; Breelle, E. [APC Laboratory, 10rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France)

2016-11-01

PACT is a space borne Pair and Compton Telescope that aims to make a sensitive survey of the gamma-ray sky between 100 keV and 100 MeV. It is based upon two main components: a silicon-based gamma-ray tracker and a crystal-based calorimeter. In this paper we will explain the imaging technique of PACT as a Multi-layered Compton telescope (0.1–10 MeV) and its major improvements over its predecessor COMPTEL. Then we will present a simulation study to optimize the silicon tracker of PACT. This tracker is formed of thousands of identical silicon double sided strip detectors (DSSDs). We have developed a simulation model (using SILVACO) to simulate the DSSD performance while varying its thickness, impurity concentration of the bulk material, electrode pitch, and electrode width. We will present a comprehensive overview of the impact of each varied parameter on the DSSD performance, in view of the application to PACT. The considered DSSD parameters are its depletion voltage, capacitance, and leakage current. After the selection of the PACT DSSD, we will present a simulation of the performance of the PACT telescope in the 0.1–10 MeV range.

A Subaru galaxy redshift survey: WFMOS survey

International Nuclear Information System (INIS)

Takada, M

2008-01-01

A planned galaxy redshift survey with the Subaru 8.2m telescope, the WFMOS survey, offers a unique opportunity for probing detailed properties of large-scale structure formation in the expanding universe by measuring clustering strength of galaxy distribution as a function of distance scale and redshift. In particular, the precise measurement of the galaxy power spectrum, combined with the cosmic microwave background experiments, allows us to obtain stringent constraints on or even determine absolute mass scales of the Big-Bang relic neutrinos as the neutrinos imprint characteristic scale- and redshift-dependent modifications onto the galaxy power spectrum shape. Here we describe the basic concept of how the galaxy clustering measurement can be used to explore the neutrino masses, with particular emphasis on advantages of the WFMOS survey over the existing low-redshift surveys such as SDSS

Development of a mid-sized Schwarzschild-Couder Telescope for the Cherenkov Telescope Array

Energy Technology Data Exchange (ETDEWEB)

Cameron, Robert A.

2012-06-28

The Cherenkov Telescope Array (CTA) is a ground-based observatory for very high-energy (10 GeV to 100 TeV) gamma rays, planned for operation starting in 2018. It will be an array of dozens of optical telescopes, known as Atmospheric Cherenkov Telescopes (ACTs), of 8 m to 24 m diameter, deployed over an area of more than 1 square km, to detect flashes of Cherenkov light from showers initiated in the Earth's atmosphere by gamma rays. CTA will have improved angular resolution, a wider energy range, larger fields of view and an order of magnitude improvement in sensitivity over current ACT arrays such as H.E.S.S., MAGIC and VERITAS. Several institutions have proposed a research and development program to eventually contribute 36 medium-sized telescopes (9 m to 12 m diameter) to CTA to enhance and optimize its science performance. The program aims to construct a prototype of an innovative, Schwarzschild-Couder telescope (SCT) design that will allow much smaller and less expensive cameras and much larger fields of view than conventional Davies-Cotton designs, and will also include design and testing of camera electronics for the necessary advances in performance, reliability and cost. We report on the progress of the mid-sized SCT development program.

A telescope with augmented reality functions

Science.gov (United States)

Hou, Qichao; Cheng, Dewen; Wang, Qiwei; Wang, Yongtian

2016-10-01

This study introduces a telescope with virtual reality (VR) and augmented reality (AR) functions. In this telescope, information on the micro-display screen is integrated to the reticule of telescope through a beam splitter and is then received by the observer. The design and analysis of telescope optical system with AR and VR ability is accomplished and the opto-mechanical structure is designed. Finally, a proof-of-concept prototype is fabricated and demonstrated. The telescope has an exit pupil diameter of 6 mm at an eye relief of 19 mm, 6° field of view, 5 to 8 times visual magnification , and a 30° field of view of the virtual image.

The Gemini 8-Meter Telescopes Project

Science.gov (United States)

Boroson, Todd A.

1995-05-01

The Gemini 8-Meter Telescopes Project is an international partnership to build and operate two 8-meter telescopes, one on Mauna Kea, Hawaii, and one on Cerro Pachon, Chile. The telescopes will be international facilities, open to the scientific communities of the six member countries, the United States (50%), the United Kingdom (25%), Canada (15%), Chile (5%), Argentina (2.5%), and Brazil (2.5%). The telescopes are designed to exploit the best atmospheric conditions at these excellent sites. Near diffraction limited performance will be delivered at 2.2 microns and longward, with minimal degradation of the best seeing conditions at shorter wavelengths. The telescopes and facilities are designed to achieve emissivity opportunity. First light for the Mauna Kea telescope is expected in late 1998, and for the Cerro Pachon telescope in mid-2000. This talk will report on construction progress, the instrumental capabilities, and operations strategies being considered. The Gemini 8-meter Telescopes Project is managed by the Association of Universities for Research in Astronomy (AURA), Inc. under a cooperative agreement with the National Science Foundation which serves as executive agency for the Gemini partner countries. U.S. participation in the project is through the U.S. Gemini Program, a division of the National Optical Astronomy Observatories. NOAO is operated by AURA, Inc. under cooperative agreement with the National Science Foundation.

Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

Science.gov (United States)

1999-11-01

replaced by COSTAR. During the second Servicing Mission instruments and other equipment were repaired and updated. The Space Telescope Imaging Spectrograph (STIS) replaced the Goddard High Resolution Spectrograph (GHRS) and the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) replaced the Faint Object Spectrograph (FOS). Servicing mission 3A The original Servicing Mission 3 (initially planned for June 2000) has been split into two missions - SM3A and SM3B - due in part to its complexity, and in part to the urgent need to replace the failed gyroscopes on board. Three gyroscopes must function to meet the telescope's very precise pointing requirements. With only two new operational, observations have had to be suspended, but the telescope will remain safely in orbit until the servicing crew arrives. During this servicing mission * all six gyroscopes will be replaced, * a Fine Guidance Sensor will be replaced, * the spacecraft's computer will be replaced by a new one which will reduce the burden of flight software maintenance and significantly lower costs, * six voltage/temperature kits will be installed to protect spacecraft batteries from overcharging and overheating if the spacecraft enters safe mode, * a new S-Band Single Access Transmitter will replace a failed spare currently aboard the spacecraft, * a solid-state recorder will be installed to replace the tape recorder, * degraded telescope thermal insulation will be replaced if time allows; this insulation is necessary to control the internal temperature on HST. For the mission to be fully successful the gyroscopes, the Fine Guidance Sensor, the computer and the voltage/temperature kits must be installed. The minimum mission success criterion is that HST will have 5 operational gyros after the mission, 4 of them newly installed. The Future During SM3B (presently scheduled for 2001) the astronauts will replace the Faint Object Camera with the Advanced Camera for Surveys (ACS), install a cooling system for

Pre-selecting muon events in the camera server of the ASTRI telescopes for the Cherenkov Telescope Array

Science.gov (United States)

Maccarone, Maria C.; Mineo, Teresa; Capalbi, Milvia; Conforti, Vito; Coffaro, Martina

2016-08-01

The Cherenkov Telescope Array (CTA) represents the next generation of ground based observatories for very high energy gamma ray astronomy. The CTA will consist of two arrays at two different sites, one in the northern and one in the southern hemisphere. The current CTA design foresees, in the southern site, the installation of many tens of imaging atmospheric Cherenkov telescopes of three different classes, namely large, medium, and small, so defined in relation to their mirror area; the northern hemisphere array would consist of few tens of the two larger telescope types. The telescopes will be equipped with cameras composed either of photomultipliers or silicon photomultipliers, and with different trigger and read-out electronics. In such a scenario, several different methods will be used for the telescopes' calibration. Nevertheless, the optical throughput of any CTA telescope, independently of its type, can be calibrated analyzing the characteristic image produced by local atmospheric highly energetic muons that induce the emission of Cherenkov light which is imaged as a ring onto the focal plane if their impact point is relatively close to the telescope optical axis. Large sized telescopes would be able to detect useful muon events under stereo coincidence and such stereo muon events will be directly addressed to the central CTA array data acquisition pipeline to be analyzed. For the medium and small sized telescopes, due to their smaller mirror area and large inter-telescope distance, the stereo coincidence rate will tend to zero; nevertheless, muon events will be detected by single telescopes that must therefore be able to identify them as possible useful calibration candidates, even if no stereo coincidence is available. This is the case for the ASTRI telescopes, proposed as pre-production units of the small size array of the CTA, which are able to detect muon events during regular data taking without requiring any dedicated trigger. We present two fast

THE GREEN BANK TELESCOPE H II REGION DISCOVERY SURVEY. IV. HELIUM AND CARBON RECOMBINATION LINES

Energy Technology Data Exchange (ETDEWEB)

Wenger, Trey V.; Bania, T. M. [Astronomy Department, 725 Commonwealth Avenue, Boston University, Boston, MA 02215 (United States); Balser, Dana S. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA, 22903-2475 (United States); Anderson, L. D. [Department of Physics, West Virginia University, Morgantown, WV 26506 (United States)

2013-02-10

The Green Bank Telescope H II Region Discovery Survey (GBT HRDS) found hundreds of previously unknown Galactic regions of massive star formation by detecting hydrogen radio recombination line (RRL) emission from candidate H II region targets. Since the HRDS nebulae lie at large distances from the Sun, they are located in previously unprobed zones of the Galactic disk. Here, we derive the properties of helium and carbon RRL emission from HRDS nebulae. Our target sample is the subset of the HRDS that has visible helium or carbon RRLs. This criterion gives a total of 84 velocity components (14% of the HRDS) with helium emission and 52 (9%) with carbon emission. For our highest quality sources, the average {sup 4}He{sup +}/H{sup +} abundance ratio by number, (y {sup +}), is 0.068 {+-} 0.023(1{sigma}). This is the same ratio as that measured for the sample of previously known Galactic H II regions. Nebulae without detected helium emission give robust y {sup +} upper limits. There are 5 RRL emission components with y {sup +} less than 0.04 and another 12 with upper limits below this value. These H II regions must have either a very low {sup 4}He abundance or contain a significant amount of neutral helium. The HRDS has 20 nebulae with carbon RRL emission but no helium emission at its sensitivity level. There is no correlation between the carbon RRL parameters and the 8 {mu}m mid-infrared morphology of these nebulae.

Cost Modeling for Space Telescope

Science.gov (United States)

Stahl, H. Philip

2011-01-01

Parametric cost models are an important tool for planning missions, compare concepts and justify technology investments. This paper presents on-going efforts to develop single variable and multi-variable cost models for space telescope optical telescope assembly (OTA). These models are based on data collected from historical space telescope missions. Standard statistical methods are used to derive CERs for OTA cost versus aperture diameter and mass. The results are compared with previously published models.

CsI Calorimeter for a Compton-Pair Telescope

Science.gov (United States)

Grove, Eric J.

We propose to build and test a hodoscopic CsI(Tl) scintillating-crystal calorimeter for a medium-energy γ-ray Compton and pair telescope. The design and technical approach for this calorimeter relies deeply on heritage from the Fermi LAT CsI Calorimeter, but it dramatically improves the low-energy performance of that design by reading out the scintillation light with silicon photomultipliers (SiPMs), making the technology developed for Fermi applicable in the Compton regime. While such a hodoscopic calorimeter is useful for an entire class of medium-energy γ-ray telescope designs, we propose to build it explicitly to support beam tests and balloon flight of the Proto-ComPair telescope, the development and construction of which was funded in a four-year APRA program beginning in 2015 ("ComPair: Steps to a Medium Energy γ-ray Mission" with PI J. McEnery of GSFC). That award did not include funding for its CsI calorimeter subsystem, and this proposal is intended to cover that gap. ComPair is a MIDEX-class instrument concept to perform a high-sensitivity survey of the γ-ray sky from 0.5 MeV to 500 MeV. ComPair is designed to provide a dramatic increase in sensitivity relative to previous instruments in this energy range (predominantly INTEGRAL/SPI and Compton COMPTEL), with the same transformative sensitivity increase - and corresponding scientific return- that the Fermi Large Area Telescope provided relative to Compton EGRET. To enable transformative science over a broad range of MeV energies and with a wide field of view, ComPair is a combined Compton telescope and pair telescope employing a silicon-strip tracker (for Compton scattering and pair conversion and tracking) and a solid-state CdZnTe calorimeter (for Compton absorption) and CsI calorimeter (for pair calorimetry), surrounded by a plastic scintillator anti-coincidence detector. Under the current proposal, we will complete the detailed design, assembly, and test of the CsI calorimeter for the risk

Hartman Testing of X-Ray Telescopes

Science.gov (United States)

Saha, Timo T.; Biskasch, Michael; Zhang, William W.

2013-01-01

Hartmann testing of x-ray telescopes is a simple test method to retrieve and analyze alignment errors and low-order circumferential errors of x-ray telescopes and their components. A narrow slit is scanned along the circumference of the telescope in front of the mirror and the centroids of the images are calculated. From the centroid data, alignment errors, radius variation errors, and cone-angle variation errors can be calculated. Mean cone angle, mean radial height (average radius), and the focal length of the telescope can also be estimated if the centroid data is measured at multiple focal plane locations. In this paper we present the basic equations that are used in the analysis process. These equations can be applied to full circumference or segmented x-ray telescopes. We use the Optical Surface Analysis Code (OSAC) to model a segmented x-ray telescope and show that the derived equations and accompanying analysis retrieves the alignment errors and low order circumferential errors accurately.

Origins Space Telescope: Tracing Dark Molecular Gas in the Milky Way

Science.gov (United States)

Narayanan, Desika; Li, Qi; Krumholz, Mark; Dave, Romeel; Origins Space Telescope Science and Technology Definition Team

2018-01-01

We present theoretical models for quantifying the fraction of CO-dark molecular gas in galaxies. To do this, we combine novel thermal, chemical, and radiative equilibrium calculations with high-resolution cosmological zoom galaxy formation models. We discuss how this dark molecular gas will be uncovered by the Origins Space Telescope, one of the four science and technology definition studies of NASA Headquarters for the 2020 Astronomy and Astrophysics Decadal survey.

VizieR Online Data Catalog: The HII Region Discovery Survey (HRDS). II. (Anderson+, 2011)

Science.gov (United States)

Anderson, L. D.; Bania, T. M.; Balser, D. S.; Rood, R. T.

2011-08-01

Our observations were made with the Green Bank Telescope (GBT) 100m telescope from 2008 June through 2010 October. We assembled our target list from the following multi-frequency, large solid angle Galactic surveys: the NRAO Very Large Array (VLA) Galactic Plane Survey at 21cm HI and continuum (VGPS: Stil et al. 2006AJ....132.1158S), the NRAO VLA Sky Survey at 20cm continuum (NVSS: Condon et al. 1998, Cat. VIII/65), the Southern Galactic Plane Survey at 21cm HI and continuum (SGPS: Haverkorn et al. 2006ApJS..167..230H), the VLA MAGPIS at 20cm continuum (Helfand et al. 2006, Cat. J/AJ/131/2525), and the Spitzer 24um MIPSGAL survey (Carey et al. 2009PASP..121...76C). Our analysis here also uses 8.0um data from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE: Benjamin et al. 2003PASP..115..953B), which were obtained with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. (4 data files).

4MOST: the 4-metre Multi-Object Spectroscopic Telescope project at preliminary design review

NARCIS (Netherlands)

de Jong, Roelof S.; Barden, Samuel C.; Bellido-Tirado, Olga; Brynnel, Joar G.; Frey, Steffen; Giannone, Domenico; Haynes, Roger; Johl, Diana; Phillips, Daniel; Schnurr, Olivier; Walcher, Jakob C.; Winkler, Roland; Ansorge, Wolfgang R.; Feltzing, Sofia; McMahon, Richard G.; Baker, Gabriella; Caillier, Patrick; Dwelly, Tom; Gaessler, Wolfgang; Iwert, Olaf; Mandel, Holger G.; Piskunov, Nikolai A.; Pragt, Johan H.; Walton, Nicholas A.; Bensby, Thomas; Bergemann, Maria; Chiappini, Cristina; Christlieb, Norbert; Cioni, Maria-Rosa L.; Driver, Simon; Finoguenov, Alexis; Helmi, Amina; Irwin, Michael J.; Kitaura, Francisco-Shu; Kneib, Jean-Paul; Liske, Jochen; Merloni, Andrea; Minchev, Ivan; Richard, Johan; Starkenburg, Else

2016-01-01

We present an overview of the 4MOST project at the Preliminary Design Review. 4MOST is a major new wide-field, high-multiplex spectroscopic survey facility under development for the VISTA telescope of ESO. 4MOST has a broad range of science goals ranging from Galactic Archaeology and stellar physics

THE TYPE Ia SUPERNOVA RATE IN RADIO AND INFRARED GALAXIES FROM THE CANADA-FRANCE-HAWAII TELESCOPE SUPERNOVA LEGACY SURVEY

International Nuclear Information System (INIS)

Graham, M. L.; Pritchet, C. J.; Balam, D.; Fabbro, S.; Sullivan, M.; Hook, I. M.; Howell, D. A.; Gwyn, S. D. J.; Astier, P.; Balland, C.; Guy, J.; Hardin, D.; Pain, R.; Regnault, N.; Basa, S.; Carlberg, R. G.; Perrett, K.; Conley, A.; Fouchez, D.; Rich, J.

2010-01-01

We have combined the large SN Ia database of the Canada-France-Hawaii Telescope Supernova Legacy Survey and catalogs of galaxies with photometric redshifts, Very Large Array 1.4 GHz radio sources, and Spitzer infrared sources. We present eight SNe Ia in early-type host galaxies which have counterparts in the radio and infrared source catalogs. We find the SN Ia rate in subsets of radio and infrared early-type galaxies is ∼1-5 times the rate in all early-type galaxies, and that any enhancement is always ∼<2σ. Rates in these subsets are consistent with predictions of the two-component 'A+B' SN Ia rate model. Since infrared properties of radio SN Ia hosts indicate dust-obscured star formation, we incorporate infrared star formation rates into the 'A+B' model. We also show the properties of SNe Ia in radio and infrared galaxies suggest the hosts contain dust and support a continuum of delay time distributions (DTDs) for SNe Ia, although other DTDs cannot be ruled out based on our data.

Amateur Telescope Making

Science.gov (United States)

Tonkin, Stephen

Many amateur astronomers make their own instruments, either because of financial considerations or because they are just interested. Amateur Telescope Making offers a variety of designs for telescopes, mounts and drives which are suitable for the home-constructor. The designs range from simple to advanced, but all are within the range of a moderately well-equipped home workshop. The book not only tells the reader what he can construct, but also what it is sensible to construct given what time is available commercially. Thus each chapter begins with reasons for undertaking the project, then looks at theoretical consideration before finishing with practical instructions and advice. An indication is given as to the skills required for the various projects. Appendices list reputable sources of (mail order) materials and components. The telescopes and mounts range from "shoestring" (very cheap) instruments to specialist devices that are unavailable commercially.

Review of lunar telescope studies at MSFC

Science.gov (United States)

Hilchey, John D.; Nein, Max E.

1993-09-01

In the near future astronomers can take advantage of the lunar surface as the new 'high ground' from which to study the universe. Optical telescopes placed and operated on the lunar surface would be successors to NASA's Great Observatories. Four telescopes, ranging in aperture from a 16-m, IR/Vis/UV observatory down to a 1-m, UV 'transit' instrument, have been studied by the Lunar Telescope Working Group and the LUTE (lunar telescope ultraviolet experiment) Task Team of the Marshall Space Flight Center (MSFC). This paper presents conceptual designs of the telescopes, provides descriptions of the telescope subsystem options selected for each concept, and outlines the potential evolution of their science capabilities.

Improving a 1 meter telescope in order to follow giant planets in a pro-am collaboration. Next step : an affordable adaptive optic system.=

Science.gov (United States)

Dauvergne, J.-L.; Colas, F.; Delcroix, M.; Lecacheux, J.

2017-09-01

We already have very good result with the 1 meter telescope of Pic du Midi. Our goal is to have more and more people in the team in order to make a survey has long as possible of Jupiter, Uranus and Neptune. The next step is an OA system, we want to make it work on the 1 meter telescope and also make it available on the market to help other observatories to produce high resolution images of the solar system with middle size telescopes.

The Submillimeter Telescope (SMT) project

International Nuclear Information System (INIS)

Martin, R.N.; Baars, J.W.M.

1990-01-01

To exploit the potential of submillimeter astronomy, the Submillimeter Telescope (SMT) will be located at an altitude of 3178 meters on Emerald Peak 75 miles northeast of Tucson in Southern Arizona. The instrument is an altazimuth mounted f/13.8 Cassegrain homology telescope with two Nasmyth and bent Cassegrain foci. It will have diffraction limited performance at a wavelength of 300 microns and an operating overall figure accuracy of 15 microns rms. An important feature of the SMT is the construction of the primary and secondary reflectors out of aluminum-core CFRP face sheet sandwich panels, and the reflector backup structure and secondary support out of CFRP structural elements. This modern technology provides both a means for reaching the required precision of the SMT for both night and day operation (basically because of the low coefficient of thermal expansion and high strength-to-weight ratio of CFRP) and a potential route for the realization of lightweight telescopes of even greater accuracy in the future. The SMT will be the highest accuracy radio telescope ever built (at least a factor of 2 more accurate than existing telescopes). In addition, the SMT will be the first 10 m-class submillimeter telescope with a surface designed for efficient measurements at the important 350 microns wavelength atmospheric window. 9 refs

History of Robotic and Remotely Operated Telescopes

Science.gov (United States)

Genet, Russell M.

2011-03-01

While automated instrument sequencers were employed on solar eclipse expeditions in the late 1800s, it wasn't until the 1960s that Art Code and associates at Wisconsin used a PDP minicomputer to automate an 8-inch photometric telescope. Although this pioneering project experienced frequent equipment failures and was shut down after a couple of years, it paved the way for the first space telescopes. Reliable microcomputers initiated the modern era of robotic telescopes. Louis Boyd and I applied single board microcomputers with 64K of RAM and floppy disk drives to telescope automation at the Fairborn Observatory, achieving reliable, fully robotic operation in 1983 that has continued uninterrupted for 28 years. In 1985 the Smithsonian Institution provided us with a suburb operating location on Mt. Hopkins in southern Arizona, while the National Science Foundation funded additional telescopes. Remote access to our multiple robotic telescopes at the Fairborn Observatory began in the late 1980s. The Fairborn Observatory, with its 14 fully robotic telescopes and staff of two (one full and one part time) illustrates the potential for low operating and maintenance costs. As the information capacity of the Internet has expanded, observational modes beyond simple differential photometry opened up, bringing us to the current era of real-time remote access to remote observatories and global observatory networks. Although initially confined to smaller telescopes, robotic operation and remote access are spreading to larger telescopes as telescopes from afar becomes the normal mode of operation.

Prospects for γ-ray imaging telescopes

International Nuclear Information System (INIS)

Carter, J.N.; Dean, A.J.; Ramsden, D.

1981-01-01

Apart from the requirement for a new, high angular-resolution gamma-ray telescope for the more precise location of known COS-B gamma-ray sources, there is also a need for another instrument that can be used in a search for the gamma-ray emission from specific X-ray-emitting objects. If there is to be any hope of relating gamma ray emission to specific candidate X-ray objects, then an angular resolution of typically a few minutes of arc is required to resolve adjacent sources in crowded regions of the sky such as the galactic centre. Efforts to improve the angular resolution of track-chamber telescopes are compared. For energies close to 1 MeV telescopes have either used collimators to restrict the field of view or have made use of the kinematics of the Compton scattering process to determine the direction of the incident photon. The use of coded aperture techniques in high angular resolution X-ray astronomy telescopes is reviewed. A practical telescope for astronomy at high energies described by Carter is mentioned. At low energies an imaging telescope could be constructed by making use of position-sensitive detectors initially developed for use in medical physics. Such a telescope is outlined in general terms and its benefits and uses given. (U.K.)

Precise starshade stationkeeping and pointing with a Zernike wavefront sensor

Science.gov (United States)

Bottom, Michael; Martin, Stefan; Seubert, Carl; Cady, Eric; Zareh, Shannon Kian; Shaklan, Stuart

2017-09-01

Starshades, large occulters positioned tens of thousands of kilometers in front of space telescopes, offer one of the few paths to imaging and characterizing Earth-like extrasolar planets. However, for a starshade to generate a sufficiently dark shadow on the telescope, the two must be coaligned to just 1 meter laterally, even at these large separations. The principal challenge to achieving this level of control is in determining the position of the starshade with respect to the space telescope. In this paper, we present numerical simulations and laboratory results demonstrating that a Zernike wavefront sensor coupled to a WFIRST-type telescope is able to deliver the stationkeeping precision required, by measuring light outside of the science wavelengths. The sensor can determine the starshade lateral position to centimeter level in seconds of open shutter time for stars brighter than eighth magnitude, with a capture range of 10 meters. We discuss the potential for fast (ms) tip/tilt pointing control at the milli-arcsecond level by illuminating the sensor with a laser mounted on the starshade. Finally, we present early laboratory results.

Status of the MAGIC telescopes

Energy Technology Data Exchange (ETDEWEB)

Colin, Pierre; Carmona, Emiliano; Schweizer, Thomas; Sitarek, Julian [Max-Planck-Institut fuer Physik, Werner-Heisenberg Institut, Muenchen (Germany)

2010-07-01

MAGIC is a system of two 17-m Cherenkov telescopes located on La Palma (Canary islands),sensitive to gamma-rays above 30 GeV. It has been recently upgraded by a second telescope which strongly improves the sensitivity, particularly at low energy. Here we present the status of the MAGIC telescopes and an overview of the recent results obtained in single or stereoscopic mode. We also discuss the real performance of the new stereoscopic system based on Crab Nebula observations.

Status of the Dark Energy Survey Camera (DECam) Project

Energy Technology Data Exchange (ETDEWEB)

Flaugher, Brenna L.; Abbott, Timothy M.C.; Angstadt, Robert; Annis, Jim; Antonik, Michelle, L.; Bailey, Jim; Ballester, Otger.; Bernstein, Joseph P.; Bernstein, Rebbeca; Bonati, Marco; Bremer, Gale; /Fermilab /Cerro-Tololo InterAmerican Obs. /ANL /Texas A-M /Michigan U. /Illinois U., Urbana /Ohio State U. /University Coll. London /LBNL /SLAC /IFAE

2012-06-29

The Dark Energy Survey Collaboration has completed construction of the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera which will be mounted on the Blanco 4-meter telescope at CTIO. DECam will be used to perform the 5000 sq. deg. Dark Energy Survey with 30% of the telescope time over a 5 year period. During the remainder of the time, and after the survey, DECam will be available as a community instrument. All components of DECam have been shipped to Chile and post-shipping checkout finished in Jan. 2012. Installation is in progress. A summary of lessons learned and an update of the performance of DECam and the status of the DECam installation and commissioning will be presented.

Status of the Dark Energy Survey Camera (DECam) project

Energy Technology Data Exchange (ETDEWEB)

Flaugher, Brenna L.; McLean, Ian S.; Ramsay, Suzanne K.; Abbott, Timothy M. C.; Angstadt, Robert; Takami, Hideki; Annis, Jim; Antonik, Michelle L.; Bailey, Jim; Ballester, Otger; Bernstein, Joseph P.; Bernstein, Rebecca A.; Bonati, Marco; Bremer, Gale; Briones, Jorge; Brooks, David; Buckley-Geer, Elizabeth J.; Campa, Juila; Cardiel-Sas, Laia; Castander, Francisco; Castilla, Javier; Cease, Herman; Chappa, Steve; Chi, Edward C.; da Costa, Luis; DePoy, Darren L.; Derylo, Gregory; de Vincente, Juan; Diehl, H. Thomas; Doel, Peter; Estrada, Juan; Eiting, Jacob; Elliott, Anne E.; Finley, David A.; Flores, Rolando; Frieman, Josh; Gaztanaga, Enrique; Gerdes, David; Gladders, Mike; Guarino, V.; Gutierrez, G.; Grudzinski, Jim; Hanlon, Bill; Hao, Jiangang; Holland, Steve; Honscheid, Klaus; Huffman, Dave; Jackson, Cheryl; Jonas, Michelle; Karliner, Inga; Kau, Daekwang; Kent, Steve; Kozlovsky, Mark; Krempetz, Kurt; Krider, John; Kubik, Donna; Kuehn, Kyler; Kuhlmann, Steve E.; Kuk, Kevin; Lahav, Ofer; Langellier, Nick; Lathrop, Andrew; Lewis, Peter M.; Lin, Huan; Lorenzon, Wolfgang; Martinez, Gustavo; McKay, Timothy; Merritt, Wyatt; Meyer, Mark; Miquel, Ramon; Morgan, Jim; Moore, Peter; Moore, Todd; Neilsen, Eric; Nord, Brian; Ogando, Ricardo; Olson, Jamieson; Patton, Kenneth; Peoples, John; Plazas, Andres; Qian, Tao; Roe, Natalie; Roodman, Aaron; Rossetto, B.; Sanchez, E.; Soares-Santos, Marcelle; Scarpine, Vic; Schalk, Terry; Schindler, Rafe; Schmidt, Ricardo; Schmitt, Richard; Schubnell, Mike; Schultz, Kenneth; Selen, M.; Serrano, Santiago; Shaw, Terri; Simaitis, Vaidas; Slaughter, Jean; Smith, R. Christopher; Spinka, Hal; Stefanik, Andy; Stuermer, Walter; Sypniewski, Adam; Talaga, R.; Tarle, Greg; Thaler, Jon; Tucker, Doug; Walker, Alistair R.; Weaverdyck, Curtis; Wester, William; Woods, Robert J.; Worswick, Sue; Zhao, Allen

2012-09-24

The Dark Energy Survey Collaboration has completed construction of the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera which will be mounted on the Blanco 4-meter telescope at CTIO. DECam will be used to perform the 5000 sq. deg. Dark Energy Survey with 30% of the telescope time over a 5 year period. During the remainder of the time, and after the survey, DECam will be available as a community instrument. All components of DECam have been shipped to Chile and post-shipping checkout finished in Jan. 2012. Installation is in progress. A summary of lessons learned and an update of the performance of DECam and the status of the DECam installation and commissioning will be presented.

Simulating the Performance of Ground-Based Optical Asteroid Surveys

Science.gov (United States)

Christensen, Eric J.; Shelly, Frank C.; Gibbs, Alex R.; Grauer, Albert D.; Hill, Richard E.; Johnson, Jess A.; Kowalski, Richard A.; Larson, Stephen M.

2014-11-01

We are developing a set of asteroid survey simulation tools in order to estimate the capability of existing and planned ground-based optical surveys, and to test a variety of possible survey cadences and strategies. The survey simulator is composed of several layers, including a model population of solar system objects and an orbital integrator, a site-specific atmospheric model (including inputs for seeing, haze and seasonal cloud cover), a model telescope (with a complete optical path to estimate throughput), a model camera (including FOV, pixel scale, and focal plane fill factor) and model source extraction and moving object detection layers with tunable detection requirements. We have also developed a flexible survey cadence planning tool to automatically generate nightly survey plans. Inputs to the cadence planner include camera properties (FOV, readout time), telescope limits (horizon, declination, hour angle, lunar and zenithal avoidance), preferred and restricted survey regions in RA/Dec, ecliptic, and Galactic coordinate systems, and recent coverage by other asteroid surveys. Simulated surveys are created for a subset of current and previous NEO surveys (LINEAR, Pan-STARRS and the three Catalina Sky Survey telescopes), and compared against the actual performance of these surveys in order to validate the model’s performance. The simulator tracks objects within the FOV of any pointing that were not discovered (e.g. too few observations, too trailed, focal plane array gaps, too fast or slow), thus dividing the population into “discoverable” and “discovered” subsets, to inform possible survey design changes. Ongoing and future work includes generating a realistic “known” subset of the model NEO population, running multiple independent simulated surveys in coordinated and uncoordinated modes, and testing various cadences to find optimal strategies for detecting NEO sub-populations. These tools can also assist in quantifying the efficiency of novel

Performance of the Multi-Spectral Solar Telescope Array. III - Optical characteristics of the Ritchey-Chretien and Cassegrain telescopes

Science.gov (United States)

Hoover, Richard B.; Baker, Phillip C.; Hadaway, James B.; Johnson, R. B.; Peterson, Cynthia; Gabardi, David R.; Walker, Arthur B., Jr.; Lindblom, J. F.; Deforest, Craig; O'Neal, R. H.

1991-12-01

The Multi-Spectral Solar Telescope Array (MSSTA), which is a sounding-rocket-borne observatory for investigating the sun in the soft X-ray/EUV and FUV regimes of the electromagnetic spectrum, utilizes single reflection multilayer coated Herschelian telescopes for wavelengths below 100 A, and five doubly reflecting multilayer coated Ritchey-Chretien and two Cassegrain telescopes for selected wavelengths in the EUV region between 100 and 1000 A. The paper discusses the interferometric alignment, testing, focusing, visible light testing, and optical performance characteristics of the Ritchey-Chretien and Cassegrain telescopes of MSSTA. A schematic diagram of the MSSTA Ritchey-Chretien telescope is presented together with diagrams of the system autocollimation testing.

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 ...

The Hubble Space Telescope: UV, Visible, and Near-Infrared Pursuits

Science.gov (United States)

Wiseman, Jennifer

2010-01-01

The Hubble Space Telescope continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3 which was installed nu last year's successful servicing mission S2N4,o{fer imaging from near-infrared through ultraviolet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to fly io space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. I will provide an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics.

Advances in Telescope and Detector Technologies - Impacts on the Study and Understanding of Binary Star and Exoplanet Systems

Science.gov (United States)

Guinan, Edward F.; Engle, Scott; Devinney, Edward J.

2012-04-01

Current and planned telescope systems (both on the ground and in space) as well as new technologies will be discussed with emphasis on their impact on the studies of binary star and exoplanet systems. Although no telescopes or space missions are primarily designed to study binary stars (what a pity!), several are available (or will be shortly) to study exoplanet systems. Nonetheless those telescopes and instruments can also be powerful tools for studying binary and variable stars. For example, early microlensing missions (mid-1990s) such as EROS, MACHO and OGLE were initially designed for probing dark matter in the halos of galaxies but, serendipitously, these programs turned out to be a bonanza for the studies of eclipsing binaries and variable stars in the Magellanic Clouds and in the Galactic Bulge. A more recent example of this kind of serendipity is the Kepler Mission. Although Kepler was designed to discover exoplanet transits (and so far has been very successful, returning many planetary candidates), Kepler is turning out to be a ``stealth'' stellar astrophysics mission returning fundamentally important and new information on eclipsing binaries, variable stars and, in particular, providing a treasure trove of data of all types of pulsating stars suitable for detailed Asteroseismology studies. With this in mind, current and planned telescopes and networks, new instruments and techniques (including interferometers) are discussed that can play important roles in our understanding of both binary star and exoplanet systems. Recent advances in detectors (e.g. laser frequency comb spectrographs), telescope networks (both small and large - e.g. Super-WASP, HAT-net, RoboNet, Las Combres Observatory Global Telescope (LCOGT) Network), wide field (panoramic) telescope systems (e.g. Large Synoptic Survey Telescope (LSST) and Pan-Starrs), huge telescopes (e.g. the Thirty Meter Telescope (TMT), the Overwhelming Large Telescope (OWL) and the Extremely Large Telescope (ELT

Astro-WISE for KiDS survey production and quality control

NARCIS (Netherlands)

Kleijn, G.V.; de Jong, Jelte; Valentijn, E.; Kuijken, K.; Consortiums, KiDS; Consortium, Astro-WISE; Ballester, P.; Egret, D.; Lorente, N.P.F.

The Kilo Degree Survey (KiDS) is a 1500 square degree optical imaging survey with the recently commissioned OmegaCAM wide-field imager on the VLT Survey Telescope (VST). A suite of data products will be delivered to ESO and the community by the KiDS survey team. Spread over Europe, the KiDS team

Commissioning and first tests of the MAGIC telescope

Science.gov (United States)

Baixeras, C.; Bastieri, D.; Bigongiari, C.; Blanch, O.; Blanchot, G.; Bock, R.; Bretz, T.; Chilingarian, A.; Coarasa, J. A.; Colombo, E.; Contreras, J. C.; Corti, D.; Cortina, J.; Domingo, C.; Domingo, E.; Ferenc, D.; Fernández, E.; Flix, J.; Fonseca, V.; Font, L.; Galante, N.; Gaug, M.; Garczarczyk, M.; Gebauer, J.; Giller, M.; Goebel, F.; Hengstebeck, T.; Jacone, P.; de Jager, O. C.; Kalekin, O.; Kestel, M.; Kneiske, T.; Laille, A.; López, M.; López, J.; Lorenz, E.; Mannheim, K.; Mariotti, M.; Martínez, M.; Mase, K.; Merck, M.; Meucci, M.; Miralles, L.; Mirzoyan, R.; Moralejo, A.; Wilhelmi, E. Oña; Orduña, R.; Paneque, D.; Paoletti, R.; Pascoli, D.; Pavel, N.; Pegna, R.; Peruzzo, L.; Piccioli, A.; Roberts, A.; Reyes, R.; Saggion, A.; Sánchez, A.; Sartori, P.; Scalzotto, V.; Schweizer, T.; Sillanpaa, A.; Sobczynska, D.; Stamerra, A.; Stepanian, A.; Stiehler, R.; Takalo, L.; Teshima, M.; Tonello, N.; Torres, A.; Turini, N.; Vitale, V.; Volkov, S.; Wagner, R. M.; Wibig, T.; Wittek, W.

2004-02-01

Major Atmospheric Gamma Imaging Cherenkov telescope is starting its operations with a set of engineering runs to tune the telescope subsystem elements to be ready for the first physics campaign. Many technical improvements have been developed and implemented in several elements of the telescope to reach the lowest energy threshold ever obtained by an Imaging Atmospheric Cherenkov Telescope. A general description of the telescope is presented. The commissioning of the telescope's elements is described and the expected performances are reviewed with the final detector set-up.

European Extremely Large Telescope: progress report

Science.gov (United States)

Tamai, R.; Spyromilio, J.

2014-07-01

The European Extremely Large Telescope is a project of the European Southern Observatory to build and operate a 40-m class optical near-infrared telescope. The telescope design effort is largely concluded and construction contracts are being placed with industry and academic/research institutes for the various components. The siting of the telescope in Northern Chile close to the Paranal site allows for an integrated operation of the facility providing significant economies. The progress of the project in various areas is presented in this paper and references to other papers at this SPIE meeting are made.

Preliminary Cost Model for Space Telescopes

Science.gov (United States)

Stahl, H. Philip; Prince, F. Andrew; Smart, Christian; Stephens, Kyle; Henrichs, Todd

2009-01-01

Parametric cost models are routinely used to plan missions, compare concepts and justify technology investments. However, great care is required. Some space telescope cost models, such as those based only on mass, lack sufficient detail to support such analysis and may lead to inaccurate conclusions. Similarly, using ground based telescope models which include the dome cost will also lead to inaccurate conclusions. This paper reviews current and historical models. Then, based on data from 22 different NASA space telescopes, this paper tests those models and presents preliminary analysis of single and multi-variable space telescope cost models.

The MEarth Project: Status Update and the Commissioning of a Brand New Telescope Array in the Southern Hemisphere

Science.gov (United States)

Berta-Thompson, Zachory K.; Irwin, Jonathan; Charbonneau, David; Newton, Elisabeth R.; Dittmann, Jason

2014-06-01

The MEarth Project is an ongoing all-sky survey for Earth-like planets transiting the closest, smallest M dwarfs. MEarth aims to find good targets for atmospheric characterization with JWST and the next generation of enormous ground-based telescopes. MEarth's yearly data releases, containing precise light curves of nearby mid-to-late M dwarfs, provide a unique window into the photometric variability of the stars that will forever be among the most interesting targets in the search for potentially habitable exoplanets. We present a status update on the MEarth Project, including a detailed map of the progress we’ve made so far with 8 telescopes in the Northern hemisphere and promising early results from our new installation of 8 more telescopes in the Southern hemisphere.

The Infrared-Optical Telescope (IRT) of the Exist Observatory

Science.gov (United States)

Kutyrev, Alexander; Bloom, Joshua; Gehrels, Neil; Golisano, Craig; Gong, Quan; Grindlay, Jonathan; Moseley, Samuel; Woodgate, Bruce

2010-01-01

The IRT is a 1.1m visible and infrared passively cooled telescope, which can locate, identify and obtain spectra of GRB afterglows at redshifts up to z 20. It will also acquire optical-IR, imaging and spectroscopy of AGN and transients discovered by the EXIST (The Energetic X-ray Imaging Survey Telescope). The IRT imaging and spectroscopic capabilities cover a broad spectral range from 0.32.2m in four bands. The identical fields of view in the four instrument bands are each split in three subfields: imaging, objective prism slitless for the field and objective prism single object slit low resolution spectroscopy, and high resolution long slit on single object. This allows the instrument, to do simultaneous broadband photometry or spectroscopy of the same object over the full spectral range, thus greatly improving the efficiency of the observatory and its detection limits. A prompt follow up (within three minutes) of the transient discovered by the EXIST makes IRT a unique tool for detection and study of these events, which is particularly valuable at wavelengths unavailable to the ground based observatories.

Surveying the skies how astronomers map the universe

CERN Document Server

Wynn-Williams, Gareth

2016-01-01

Since the time of Galileo, astronomy has been driven by technological innovation. With each major advance has come the opportunity and enthusiasm to survey the sky in a way that was not possible before. It is these surveys of discovery that are the subject of this book. In the first few chapters the author discusses what astronomers learned from visible-light surveys, first with the naked eye, then using telescopes in the seventeenth century, and photography in the nineteenth century. He then moves to the second half of the twentieth century when the skies started to be swept by radio, infrared, ultraviolet, x-ray and gamma ray telescopes, many of which had to be flown in satellites above the Earth’s atmosphere. These surveys led to the discovery of pulsars, quasars, molecular clouds, protostars, bursters, and black holes. He then returns to Earth to describe several currently active large-scale projects that methodically collect images, photometry and spectra that are then stored in vast publicly-accessibl...

Deep Extragalactic VIsible Legacy Survey (DEVILS): Motivation, Design and Target Catalogue

Science.gov (United States)

Davies, L. J. M.; Robotham, A. S. G.; Driver, S. P.; Lagos, C. P.; Cortese, L.; Mannering, E.; Foster, C.; Lidman, C.; Hashemizadeh, A.; Koushan, S.; O'Toole, S.; Baldry, I. K.; Bilicki, M.; Bland-Hawthorn, J.; Bremer, M. N.; Brown, M. J. I.; Bryant, J. J.; Catinella, B.; Croom, S. M.; Grootes, M. W.; Holwerda, B. W.; Jarvis, M. J.; Maddox, N.; Meyer, M.; Moffett, A. J.; Phillipps, S.; Taylor, E. N.; Windhorst, R. A.; Wolf, C.

2018-06-01

The Deep Extragalactic VIsible Legacy Survey (DEVILS) is a large spectroscopic campaign at the Anglo-Australian Telescope (AAT) aimed at bridging the near and distant Universe by producing the highest completeness survey of galaxies and groups at intermediate redshifts (0.3 < z < 1.0). Our sample consists of ˜60,000 galaxies to Y<21.2 mag, over ˜6 deg2 in three well-studied deep extragalactic fields (Cosmic Origins Survey field, COSMOS, Extended Chandra Deep Field South, ECDFS and the X-ray Multi-Mirror Mission Large-Scale Structure region, XMM-LSS - all Large Synoptic Survey Telescope deep-drill fields). This paper presents the broad experimental design of DEVILS. Our target sample has been selected from deep Visible and Infrared Survey Telescope for Astronomy (VISTA) Y-band imaging (VISTA Deep Extragalactic Observations, VIDEO and UltraVISTA), with photometry measured by PROFOUND. Photometric star/galaxy separation is done on the basis of NIR colours, and has been validated by visual inspection. To maximise our observing efficiency for faint targets we employ a redshift feedback strategy, which continually updates our target lists, feeding back the results from the previous night's observations. We also present an overview of the initial spectroscopic observations undertaken in late 2017 and early 2018.

NASA Telescopes Help Identify Most Distant Galaxy Cluster

Science.gov (United States)

2011-01-01

electromagnetic spectrum, from X-ray to millimeter wavelengths, were all critical in providing a comprehensive view of the cluster's many facets." COSMOS-AzTEC3, located in the constellation Sextans, is named after the region where it was found, called COSMOS after the Cosmic Evolution Survey. AzTEC is the name of the camera used on the James Clerk Maxwell Telescope -- this camera is now on its way to the Large Millimeter Telescope located in Mexico's Puebla state. For more information about NASA's Spitzer, Chandra and Hubble space telescopes, visit: http://www.nasa.gov/chandra http://www.nasa.gov/spitzer http://www.nasa.gov/hubble

The site conditions of the Guo Shou Jing Telescope

International Nuclear Information System (INIS)

Yao Song; Liu Chao; Zhang Haotong; Deng Licai; Zhang Yueyang; Li Jing; Liu Nian; Zhou Xu; Gao Shuang; Xu Yan; Newberg, Heidi Jo; Carlin, Jeffrey L.; Chen Li; Hou Jinliang; Christlieb Norbert; Han Zhanwen; Lee, Hsu-Tai; Liu Xiaowei; Pan Kaike; Wang Hongchi

2012-01-01

The weather at the Xinglong Observing Station, where the Guo Shou Jing Telescope (GSJT) is located, is strongly affected by the monsoon climate in northeast China. The LAMOST survey strategy is constrained by these weather patterns. We present statistics on observing hours from 2004 to 2007, and the sky brightness, seeing, and sky transparency from 1995 to 2011 at the site. We investigate effects of the site conditions on the survey plan. Operable hours each month show a strong correlation with season: on average there are eight operable hours per night available in December, but only one—two hours in July and August. The seeing and the sky transparency also vary with season. Although the seeing is worse in windy winters, and the atmospheric extinction is worse in the spring and summer, the site is adequate for the proposed scientific program of the LAMOST survey. With a Monte Carlo simulation using historical data on the site condition, we find that the available observation hours constrain the survey footprint from 22 h to 16 h in right ascension; the sky brightness allows LAMOST to obtain a limiting magnitude of V = 19.5 mag with S/N=10.

Three-reflections telescope proposal as flat-field anastigmat for wide field observations at Dome C

Science.gov (United States)

Ferrari, M.; Lemaître, G.; Viotti, R.; La Padula, C.; Comte, G.; Blanc, M.; Boer, M.

It is now evident that the exceptional seeing at Dome C will allow, in the next years, to pursue astronomical programs with conditions better than at any other observatory in the world, and very close to space experiments. Considering a new type of wide-field telescope, particular astronomical programs could be well optimized for observations at Dome C such as surveys for the discovery and follow up of near-Earth asteroids, search for extra-solar planets using transit or micro-lensing events, and stellar luminosity variations. We propose to build a 1.5 2m class three-reflections telescope, with 1 1.5degree FOV, four times shorter than an equivalent Schmidt telescope, and providing a flat field without requiring a triplet- or quadruplet-lens corrector since its design is anastigmatic. We present the preliminary optical tests of such designs: MINITRUST1 and 2 are two 45cm identical prototypes based in France and Italy, and manufactured using active optics techniques.

Open principle for large high-resolution solar telescopes

NARCIS (Netherlands)

Hammerschlag, R.H.; Bettonvil, F.C.M.; Jägers, A.P.L.; Sliepen, G.

2009-01-01

Vacuum solar telescopes solve the problem of image deterioration inside the telescope due to refractive index fluctuations of the air heated by the solar light. However, such telescopes have a practical diameter limit somewhat over 1 m. The Dutch Open Telescope (DOT) was the pioneering demonstrator

Analysis of polarization introduced due to the telescope optics of the Thirty Meter Telescope

Science.gov (United States)

Anche, Ramya Manjunath; Sen, Asoke Kumar; Anupama, Gadiyara Chakrapani; Sankarasubramanian, Kasiviswanathan; Skidmore, Warren

2018-01-01

An analytical model has been developed to estimate the polarization effects, such as instrumental polarization (IP), crosstalk (CT), and depolarization, due to the optics of the Thirty Meter Telescope. These are estimated for the unvignetted field-of-view and the wavelengths of interest. The model estimates an IP of 1.26% and a CT of 44% at the Nasmyth focus of the telescope at the wavelength of 0.6 μm at field angle zero with the telescope pointing to zenith. Mueller matrices have been estimated for the primary, secondary, and Nasmyth mirrors. It is found that some of the Mueller matrix elements of the primary and secondary mirrors show a fourfold azimuthal antisymmetry, which indicates that the polarization at the Cassegrain focus is negligible. At the inclined Nasmyth mirror, there is no azimuthal antisymmetry in the matrix elements, and this results in nonzero values for IP and CT, which would negatively impact the polarization measurements at the telescope focus. The averaged Mueller matrix is estimated at the Nasmyth focus at different instrument ports and various zenith angles of the telescope. The variation in the Mueller matrix elements for different coatings is also estimated. The impact of this polarization effect on the science case requirements has been discussed. This analysis will help in achieving precise requirements for future instruments with polarimetric capability.

End-to-end simulations and planning of a small space telescopes: Galaxy Evolution Spectroscopic Explorer: a case study

Science.gov (United States)

Heap, Sara; Folta, David; Gong, Qian; Howard, Joseph; Hull, Tony; Purves, Lloyd

2016-08-01

Large astronomical missions are usually general-purpose telescopes with a suite of instruments optimized for different wavelength regions, spectral resolutions, etc. Their end-to-end (E2E) simulations are typically photons-in to flux-out calculations made to verify that each instrument meets its performance specifications. In contrast, smaller space missions are usually single-purpose telescopes, and their E2E simulations start with the scientific question to be answered and end with an assessment of the effectiveness of the mission in answering the scientific question. Thus, E2E simulations for small missions consist a longer string of calculations than for large missions, as they include not only the telescope and instrumentation, but also the spacecraft, orbit, and external factors such as coordination with other telescopes. Here, we illustrate the strategy and organization of small-mission E2E simulations using the Galaxy Evolution Spectroscopic Explorer (GESE) as a case study. GESE is an Explorer/Probe-class space mission concept with the primary aim of understanding galaxy evolution. Operation of a small survey telescope in space like GESE is usually simpler than operations of large telescopes driven by the varied scientific programs of the observers or by transient events. Nevertheless, both types of telescopes share two common challenges: maximizing the integration time on target, while minimizing operation costs including communication costs and staffing on the ground. We show in the case of GESE how these challenges can be met through a custom orbit and a system design emphasizing simplification and leveraging information from ground-based telescopes.

Automated extinction monitor for the NLOT site survey

Science.gov (United States)

Kumar Sharma, Tarun

In order to search a few potential sites for the National Large Optical Telescope (NLOT) project, we have initiated a site survey program. Since, most of instruments used for the site survey are custom made, we also started developing our own site characterization instruments. In this process we have designed and developed a device called Automated Extinction Monitor (AEM) and installed the same at IAO, Hanle. The AEM is a small wide field robotic telescope, dedicated to record atmospheric extinction in one or more photometric bands. It gives very accurate statistics of the distribution of photometric nights. In addition to this, instrument also provides the measurement of sky brightness. Here we briefly describe overall instrument and initial results obtained.

Hungaria asteroid region telescopic spectral survey (HARTSS) I: Stony asteroids abundant in the Hungaria background population

Science.gov (United States)

Lucas, Michael P.; Emery, Joshua P.; Pinilla-Alonso, Noemi; Lindsay, Sean S.; Lorenzi, Vania

2017-07-01

The Hungaria asteroids remain as survivors of late giant planet migration that destabilized a now extinct inner portion of the primordial asteroid belt and left in its wake the current resonance structure of the Main Belt. In this scenario, the Hungaria region represents a ;purgatory; for the closest, preserved samples of the asteroidal material from which the terrestrial planets accreted. Deciphering the surface composition of these unique samples may provide constraints on the nature of the primordial building blocks of the terrestrial planets. We have undertaken an observational campaign entitled the Hungaria Asteroid Region Telescopic Spectral Survey (HARTSS) to record near-infrared (NIR) reflectance spectra in order to characterize their taxonomy, surface mineralogy, and potential meteorite analogs. The overall objective of HARTSS is to evaluate the compositional diversity of asteroids located throughout the Hungaria region. This region harbors a collisional family of Xe-type asteroids, which are situated among a background (i.e., non-family) of predominantly S-complex asteroids. In order to assess the compositional diversity of the Hungaria region, we have targeted background objects during Phase I of HARTSS. Collisional family members likely reflect the composition of one original homogeneous parent body, so we have largely avoided them in this phase. We have employed NIR instruments at two ground-based telescope facilities: the NASA Infrared Telescope Facility (IRTF), and the Telescopio Nazionale Galileo (TNG). Our data set includes the NIR spectra of 42 Hungaria asteroids (36 background; 6 family). We find that stony S-complex asteroids dominate the Hungaria background population (29/36 objects; ∼80%). C-complex asteroids are uncommon (2/42; ∼5%) within the Hungaria region. Background S-complex objects exhibit considerable spectral diversity as band parameter measurements of diagnostic absorption features near 1- and 2-μm indicate that several

MAPPING THE GALAXY COLOR–REDSHIFT RELATION: OPTIMAL PHOTOMETRIC REDSHIFT CALIBRATION STRATEGIES FOR COSMOLOGY SURVEYS

Energy Technology Data Exchange (ETDEWEB)

Masters, Daniel; Steinhardt, Charles; Faisst, Andreas [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Capak, Peter [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, Daniel; Rhodes, Jason [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Ilbert, Olivier [Aix Marseille Universite, CNRS, LAM (Laboratoire dAstrophysique de Marseille) UMR 7326, F-13388, Marseille (France); Salvato, Mara [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Schmidt, Samuel [Department of Physics, University of California, Davis, CA 95616 (United States); Longo, Giuseppe [Department of Physics, University Federico II, via Cinthia 6, I-80126 Napoli (Italy); Paltani, Stephane; Coupon, Jean [Department of Astronomy, University of Geneva ch. dcogia 16, CH-1290 Versoix (Switzerland); Mobasher, Bahram [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Hoekstra, Henk [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA, Leiden (Netherlands); Hildebrandt, Hendrik [Argelander-Institut für Astronomie, Universität Bonn, Auf dem H’´ugel 71, D-53121 Bonn (Germany); Speagle, Josh [Department of Astronomy, Harvard University, 60 Garden Street, MS 46, Cambridge, MA 02138 (United States); Kalinich, Adam [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Brodwin, Mark [Department of Physics and Astronomy, University of Missouri, Kansas City, MO 64110 (United States); Brescia, Massimo; Cavuoti, Stefano [Astronomical Observatory of Capodimonte—INAF, via Moiariello 16, I-80131, Napoli (Italy)

2015-11-01

Calibrating the photometric redshifts of ≳10{sup 9} galaxies for upcoming weak lensing cosmology experiments is a major challenge for the astrophysics community. The path to obtaining the required spectroscopic redshifts for training and calibration is daunting, given the anticipated depths of the surveys and the difficulty in obtaining secure redshifts for some faint galaxy populations. Here we present an analysis of the problem based on the self-organizing map, a method of mapping the distribution of data in a high-dimensional space and projecting it onto a lower-dimensional representation. We apply this method to existing photometric data from the COSMOS survey selected to approximate the anticipated Euclid weak lensing sample, enabling us to robustly map the empirical distribution of galaxies in the multidimensional color space defined by the expected Euclid filters. Mapping this multicolor distribution lets us determine where—in galaxy color space—redshifts from current spectroscopic surveys exist and where they are systematically missing. Crucially, the method lets us determine whether a spectroscopic training sample is representative of the full photometric space occupied by the galaxies in a survey. We explore optimal sampling techniques and estimate the additional spectroscopy needed to map out the color–redshift relation, finding that sampling the galaxy distribution in color space in a systematic way can efficiently meet the calibration requirements. While the analysis presented here focuses on the Euclid survey, similar analysis can be applied to other surveys facing the same calibration challenge, such as DES, LSST, and WFIRST.

Technological Aspects of Creating Large-size Optical Telescopes

Directory of Open Access Journals (Sweden)

V. V. Sychev

2015-01-01

Full Text Available A concept of the telescope creation, first of all, depends both on a choice of the optical scheme to form optical radiation and images with minimum losses of energy and information and on a choice of design to meet requirements for strength, stiffness, and stabilization characteristics in real telescope operation conditions. Thus, the concept of creating large-size telescopes, certainly, involves the use of adaptive optics methods and means.The level of technological capabilities to realize scientific and engineering ideas define a successful development of large-size optical telescopes in many respects. All developers pursue the same aim that is to raise an amount of information by increasing a main mirror diameter of the telescope.The article analyses the adaptive telescope designs developed in our country. Using a domestic ACT-25 telescope as an example, it considers creation of large-size optical telescopes in terms of technological aspects. It also describes the telescope creation concept features, which allow reaching marginally possible characteristics to ensure maximum amount of information.The article compares a wide range of large-size telescopes projects. It shows that a domestic project to create the adaptive ACT-25 super-telescope surpasses its foreign counterparts, and there is no sense to implement Euro50 (50m and OWL (100m projects.The considered material gives clear understanding on a role of technological aspects in development of such complicated optic-electronic complexes as a large-size optical telescope. The technological criteria of an assessment offered in the article, namely specific informational content of the telescope, its specific mass, and specific cost allow us to reveal weaknesses in the project development and define a reserve regarding further improvement of the telescope.The analysis of results and their judgment have shown that improvement of optical largesize telescopes in terms of their maximum

Development of the focal plane PNCCD camera system for the X-ray space telescope eROSITA

International Nuclear Information System (INIS)

Meidinger, Norbert; Andritschke, Robert; Ebermayer, Stefanie; Elbs, Johannes; Haelker, Olaf; Hartmann, Robert; Herrmann, Sven; Kimmel, Nils; Schaechner, Gabriele; Schopper, Florian; Soltau, Heike; Strueder, Lothar; Weidenspointner, Georg

2010-01-01

A so-called PNCCD, a special type of CCD, was developed twenty years ago as focal plane detector for the XMM-Newton X-ray astronomy mission of the European Space Agency ESA. Based on this detector concept and taking into account the experience of almost ten years of operation in space, a new X-ray CCD type was designed by the 'MPI semiconductor laboratory' for an upcoming X-ray space telescope, called eROSITA (extended Roentgen survey with an imaging telescope array). This space telescope will be equipped with seven X-ray mirror systems of Wolter-I type and seven CCD cameras, placed in their foci. The instrumentation permits the exploration of the X-ray universe in the energy band from 0.3 up to 10 keV by spectroscopic measurements with a time resolution of 50 ms for a full image comprising 384x384 pixels. Main scientific goals are an all-sky survey and investigation of the mysterious 'Dark Energy'. The eROSITA space telescope, which is developed under the responsibility of the 'Max-Planck-Institute for extraterrestrial physics', is a scientific payload on the new Russian satellite 'Spectrum-Roentgen-Gamma' (SRG). The mission is already approved by the responsible Russian and German space agencies. After launch in 2012 the destination of the satellite is Lagrange point L2. The planned observational program takes about seven years. We describe the design of the eROSITA camera system and present important test results achieved recently with the eROSITA prototype PNCCD detector. This includes a comparison of the eROSITA detector with the XMM-Newton detector.

A MegaCam Survey of Outer Halo Satellites. I. Description of the Survey

Science.gov (United States)

Muñoz, Ricardo R.; Côté, Patrick; Santana, Felipe A.; Geha, Marla; Simon, Joshua D.; Oyarzún, Grecco A.; Stetson, Peter B.; Djorgovski, S. G.

2018-06-01

We describe a deep, systematic imaging study of satellites in the outer halo of the Milky Way. Our sample consists of 58 stellar overdensities—i.e., substructures classified as either globular clusters, classical dwarf galaxies, or ultra-faint dwarf galaxies—that are located at Galactocentric distances of R GC ≥ 25 kpc (outer halo) and out to ∼400 kpc. This includes 44 objects for which we have acquired deep, wide-field, g- and r-band imaging with the MegaCam mosaic cameras on the 3.6 m Canada–France–Hawaii Telescope and the 6.5 m Magellan-Clay telescope. These data are supplemented by archival imaging, or published gr photometry, for an additional 14 objects, most of which were discovered recently in the Dark Energy Survey (DES). We describe the scientific motivation for our survey, including sample selection, observing strategy, data reduction pipeline, calibration procedures, and the depth and precision of the photometry. The typical 5σ point-source limiting magnitudes for our MegaCam imaging—which collectively covers an area of ≈52 deg2—are g lim ≃ 25.6 and r lim ≃ 25.3 AB mag. These limits are comparable to those from the coadded DES images and are roughly a half-magnitude deeper than will be reached in a single visit with the Large Synoptic Survey Telescope. Our photometric catalog thus provides the deepest and most uniform photometric database of Milky Way satellites available for the foreseeable future. In other papers in this series, we have used these data to explore the blue straggler populations in these objects, their density distributions, star formation histories, scaling relations, and possible foreground structures.

Arecibo PALFA survey and Einstein@Home: binary pulsar discovery by volunteer computing

NARCIS (Netherlands)

Knispel, B.; Lazarus, P.; Allen, B.; Anderson, D.; Aulbert, C.; Bhat, N.D.R.; Bock, O.; Bogdanov, S.; Brazier, A.; Camilo, F.; Chatterjee, S.; Cordes, J.M.; Crawford, F.; Deneva, J.S.; Desvignes, G.; Fehrmann, H.; Freire, P.C.C.; Hammer, D.; Hessels, J.W.T.; Jenet, F.A.; Kaspi, V.M.; Kramer, M.; van Leeuwen, J.; Lorimer, D.R.; Lyne, A.G.; Machenschalk, B.; McLaughlin, M.A.; Messenger, C.; Nice, D.J.; Papa, M.A.; Pletsch, H.J.; Prix, R.; Ransom, S.M.; Siemens, X.; Stairs, I.H.; Stappers, B.W.; Stovall, K.; Venkataraman, A.

2011-01-01

We report the discovery of the 20.7 ms binary pulsar J1952+2630, made using the distributed computing project Einstein@Home in Pulsar ALFA survey observations with the Arecibo telescope. Follow-up observations with the Arecibo telescope confirm the binary nature of the system. We obtain a circular

A molecular line survey toward the nearby galaxies NGC 1068, NGC 253, and IC 342 at 3 mm with the Nobeyama 45 m radio telescope: Impact of an AGN on 1 kpc scale molecular abundances

Science.gov (United States)

Nakajima, Taku; Takano, Shuro; Kohno, Kotaro; Harada, Nanase; Herbst, Eric

2018-01-01

It is important to investigate the relationships between the power sources and the chemical compositions of galaxies in order to understand the scenario of galaxy evolution. We carried out an unbiased molecular line survey towards active galactic nucleus (AGN) host galaxy NGC1068, and prototypical starburst galaxies, NGC 253 and IC 342, with the Nobeyama 45 m telescope in the 3 mm band. The advantage of this line survey is that the obtained spectra have the highest angular resolution ever obtained with single-dish telescopes. In particular, the beam size of this telescope is ˜15″-19″, which is able to separate spatially the nuclear molecular emission from that of the starburst ring (d ˜ 30″) in NGC 1068. We successfully detected approximately 23 molecular species in each galaxy, and calculated rotation temperatures and column densities. We estimate the molecular fractional abundances with respect to 13CO and CS molecules and compare them among three galaxies in order to investigate the chemical signatures of an AGN environment. As a result, we found clear trends in the abundances of molecules surrounding the AGN on a 1-kpc scale. HCN, H13CN, CN, 13CN, and HC3N are more abundant, and CH3CCH is deficient in NGC 1068 compared with the starburst galaxies. High abundances of HCN, H13CN, and HC3N suggest that the circumnuclear disk in NGC 1068 is in a high-temperature environment. The reason for the non-detection of CH3CCH is likely to be dissociation by high-energy radiation or less sublimation of a precursor of CH3CCH from grains.

Neutrino telescopes in the World

International Nuclear Information System (INIS)

Ernenwein, J.-P.

2007-01-01

Neutrino astronomy has rapidly developed these last years, being the only way to get specific and reliable information about astrophysical objects still poorly understood.Currently two neutrino telescopes are operational in the World: BAIKAL, in the lake of the same name in Siberia, and AMANDA, in the ices of the South Pole. Two telescopes of the same type are under construction in the Mediterranean Sea: ANTARES and NESTOR. All these telescopes belong to a first generation, with an instrumented volume smaller or equal to 0.02 km3. Also in the Mediterranean Sea, the NEMO project is just in its starting phase, within the framework of a cubic kilometer size neutrino telescope study. Lastly, the ICECUBE detector, with a volume reaching about 1 km3, is under construction on the site of AMANDA experiment, while an extension of the BAIKAL detector toward km3 is under study. We will present here the characteristics of these experiments, as well as the results of their observations

The Liverpool Telescope: rapid follow-up observation of targets of opportunity with a 2 m robotic telescope

International Nuclear Information System (INIS)

Gomboc, Andreja; Bode, Michael F.; Carter, David; Mundell, Carol G.; Newsam, Andrew; Smith, Robert J.; Steele, Iain A.

2004-01-01

The Liverpool Telescope, situated at Roque de los Muchachos Observatory, La Palma, Canaries, is the first 2-m, fully instrumented robotic telescope. It recently began observations. Among Liverpool Telescope's primary scientific goals is to monitor variable objects on all timescales from seconds to years. An additional benefit of its robotic operation is rapid reaction to unpredictable phenomena and their systematic follow up, simultaneous or coordinated with other facilities. The Target of Opportunity Programme of the Liverpool Telescope includes the prompt search for and observation of GRB and XRF counterparts. A special over-ride mode implemented for GRB/XRF follow-up enables observations commencing less than a minute after the alert, including optical and near infrared imaging and spectroscopy. In particular, the moderate aperture and rapid automated response make the Liverpool Telescope excellently suited to help solving the mystery of optically dark GRBs and for the investigation of currently unstudied short bursts and XRFs

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.

ANTARES: The first undersea neutrino telescope

International Nuclear Information System (INIS)

Ageron, M.; Aguilar, J.A.; Al Samarai, I.; Albert, A.; Ameli, F.; Andre, 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.

2011-01-01

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.

The Dutch Open Telescope: History, Status, Prospects

NARCIS (Netherlands)

Rutten, R.J.

1999-01-01

After many years of persistent telescope design and telescope construction, R.H. Hammerschlag has installed his Dutch Open Telescope (DOT) on La Palma. I brie y review its history and design. The future of optical solar physics at Utrecht hinges on a recently-funded three- year DOT science

A virtual reality environment for telescope operation

Science.gov (United States)

Martínez, Luis A.; Villarreal, José L.; Ángeles, Fernando; Bernal, Abel

2010-07-01

Astronomical observatories and telescopes are becoming increasingly large and complex systems, demanding to any potential user the acquirement of great amount of information previous to access them. At present, the most common way to overcome that information is through the implementation of larger graphical user interfaces and computer monitors to increase the display area. Tonantzintla Observatory has a 1-m telescope with a remote observing system. As a step forward in the improvement of the telescope software, we have designed a Virtual Reality (VR) environment that works as an extension of the remote system and allows us to operate the telescope. In this work we explore this alternative technology that is being suggested here as a software platform for the operation of the 1-m telescope.

The afocal telescope optical design and tolerance analysis for the ESA ARIEL mission

Science.gov (United States)

Da Deppo, Vania; Middleton, Kevin; Focardi, Mauro; Morgante, Gianluca; Grella, Samuele; Claudi, Riccardo; Pace, Emanuele; Ficai Veltroni, Iacopo; Micela, Giuseppina

2017-11-01

ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is one of the three present candidates for the next ESA medium-class science mission (M4) to be launched in 2026. During its 3.5 years of scientific operations from L2 orbit, this mission will observe spectroscopically in the infrared (IR) a large population of known transiting planets in the neighbourhood of the Solar System. The aim is to enable a deep understanding of the physics and chemistry of these exoplanets. ARIEL is based on a 1-m class telescope ahead of a suite of instruments: two spectrometer channels covering the band 1.95 to 7.80 µm and four photometric channels (two wide and two narrow band) in the range 0.5 to 1.9 μm. The ARIEL optical design is conceived as a fore-module common afocal telescope that will feed the spectrometer and photometric channels. The telescope optical design is based on an eccentric pupil two-mirror classic Cassegrain configuration coupled to a tertiary paraboloidal mirror. An all-aluminum structure has been considered for the telescope layout, and a detailed tolerance analysis has been conducted to assess the telescope feasibility. This analysis has been done including the different parts of the realization and life of the instrument, from integration on-ground to in-flight stability during the scientific acquisitions. The primary mirror (M1) temperature will be monitored and finely tuned via an active thermal control system based on thermistors and heaters. The heaters will be switched on and off to maintain the M1 temperature within ±1K thanks to a proportional-integral-derivative (PID) controller.

Automatic Photoelectric Telescope Service

International Nuclear Information System (INIS)

Genet, R.M.; Boyd, L.J.; Kissell, K.E.; Crawford, D.L.; Hall, D.S.; BDM Corp., McLean, VA; Kitt Peak National Observatory, Tucson, AZ; Dyer Observatory, Nashville, TN)

1987-01-01

Automatic observatories have the potential of gathering sizable amounts of high-quality astronomical data at low cost. The Automatic Photoelectric Telescope Service (APT Service) has realized this potential and is routinely making photometric observations of a large number of variable stars. However, without observers to provide on-site monitoring, it was necessary to incorporate special quality checks into the operation of the APT Service at its multiple automatic telescope installation on Mount Hopkins. 18 references

The ATHENA telescope and optics status

Science.gov (United States)

Bavdaz, Marcos; Wille, Eric; Ayre, Mark; Ferreira, Ivo; Shortt, Brian; Fransen, Sebastiaan; Collon, Maximilien; Vacanti, Giuseppe; Barriere, Nicolas; Landgraf, Boris; Haneveld, Jeroen; van Baren, Coen; Zuknik, Karl-Heintz; Della Monica Ferreira, Desiree; Massahi, Sonny; Christensen, Finn; Krumrey, Michael; Burwitz, Vadim; Pareschi, Giovanni; Spiga, Daniele; Valsecchi, Giuseppe; Vernani, Dervis; Oliver, Paul; Seidel, André

2017-08-01

The work on the definition and technological preparation of the ATHENA (Advanced Telescope for High ENergy Astrophysics) mission continues to progress. In parallel to the study of the accommodation of the telescope, many aspects of the X-ray optics are being evolved further. The optics technology chosen for ATHENA is the Silicon Pore Optics (SPO), which hinges on technology spin-in from the semiconductor industry, and uses a modular approach to produce large effective area lightweight telescope optics with a good angular resolution. Both system studies and the technology developments are guided by ESA and implemented in industry, with participation of institutional partners. In this paper an overview of the current status of the telescope optics accommodation and technology development activities is provided.

Spectroscopic Classification of Nine Optical Transients with the 2.5-m du Pont Telescope

Science.gov (United States)

Bose, Subhash; Holoien, Tom; Prieto, Jose L.; Dong, Subo; Chen, P.; Stanek, K. Z.

2018-04-01

We report spectroscopic observations and classifications of optical transients using the du Pont 2.5-m telescope (+ WFCCD) at Las Campanas Observatory. Targets were discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN, Shappee et al. 2014) (ATel #11391, ATel #11343, ATel #11459), Gaia Alerts (http://gsaweb.ast.cam.ac.uk/alerts/alertsindex) and A. Rest et al. (for 2018agk).

Hard x-ray telescope mission

DEFF Research Database (Denmark)

Gorenstein, P.; Worrall, D.; Joensen, K.D.

1996-01-01

The Hard X-Ray Telescope was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity...

21 CFR 886.5870 - Low-vision telescope.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Low-vision telescope. 886.5870 Section 886.5870...) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5870 Low-vision telescope. (a) Identification. A low-vision telescope is a device that consists of an arrangement of lenses or mirrors intended for...

TRANSIT SURVEYS FOR EARTHS IN THE HABITABLE ZONES OF WHITE DWARFS

International Nuclear Information System (INIS)

Agol, Eric

2011-01-01

To date the search for habitable Earth-like planets has primarily focused on nuclear burning stars. I propose that this search should be expanded to cool white dwarf stars that have expended their nuclear fuel. I define the continuously habitable zone of white dwarfs and show that it extends from ∼0.005 to 0.02 AU for white dwarfs with masses from 0.4 to 0.9 M sun , temperatures less than ∼10 4 K, and habitable durations of at least 3 Gyr. As they are similar in size to Earth, white dwarfs may be deeply eclipsed by terrestrial planets that orbit edge-on, which can easily be detected with ground-based telescopes. If planets can migrate inward or reform near white dwarfs, I show that a global robotic telescope network could carry out a transit survey of nearby white dwarfs placing interesting constraints on the presence of habitable Earths. If planets were detected, I show that the survey would favor detection of planets similar to Earth: similar size, temperature, and rotation period, and host star temperatures similar to the Sun. The Large Synoptic Survey Telescope could place even tighter constraints on the frequency of habitable Earths around white dwarfs. The confirmation and characterization of these planets might be carried out with large ground and space telescopes.

LAMOST spectral survey — An overview

International Nuclear Information System (INIS)

Zhao Gang; Zhao Yongheng; Chu Yaoquan; Deng Licai; Jing Yipeng

2012-01-01

LAMOST (Large sky Area Multi-Object fiber Spectroscopic Telescope) is a Chinese national scientific research facility operated by National Astronomical Observatories, Chinese Academy of Sciences (NAOC). After two years of commissioning beginning in 2009, the telescope, instruments, software systems and operations are nearly ready to begin the main science survey. Through a spectral survey of millions of objects in much of the northern sky, LAMOST will enable research in a number of contemporary cutting edge topics in astrophysics, such as discovery of the first generation stars in the Galaxy, pinning down the formation and evolution history of galaxies — especially the Milky Way and its central massive black hole, and looking for signatures of the distribution of dark matter and possible sub-structures in the Milky Way halo. To maximize the scientific potential of the facility, wide national participation and international collaboration have been emphasized. The survey has two major components: the LAMOST ExtraGAlactic Survey (LEGAS) and the LAMOST Experiment for Galactic Understanding and Exploration (LEGUE). Until LAMOST reaches its full capability, the LEGUE portion of the survey will use the available observing time, starting in 2012. An overview of the LAMOST project and the survey that will be carried out in the next five to six years is presented in this paper. The science plan for the whole LEGUE survey, instrumental specifications, site conditions, and the descriptions of the current on-going pilot survey, including its footprints and target selection algorithm, will be presented as separate papers in this volume.

The High Time Resolution Universe surveys for pulsars and fast transients

Science.gov (United States)

Keith, Michael J.

2013-03-01

The High Time Resolution Universe survey for pulsars and transients is the first truly all-sky pulsar survey, taking place at the Parkes Radio Telescope in Australia and the Effelsberg Radio Telescope in Germany. Utilising multibeam receivers with custom built all-digital recorders the survey targets the fastest millisecond pulsars and radio transients on timescales of 64 μs to a few seconds. The new multibeam digital filter-bank system at has a factor of eight improvement in frequency resolution over previous Parkes multibeam surveys, allowing us to probe further into the Galactic plane for short duration signals. The survey is split into low, mid and high Galactic latitude regions. The mid-latitude portion of the southern hemisphere survey is now completed, discovering 107 previously unknown pulsars, including 26 millisecond pulsars. To date, the total number of discoveries in the combined survey is 135 and 29 MSPs These discoveries include the first magnetar to be discovered by it's radio emission, unusual low-mass binaries, gamma-ray pulsars and pulsars suitable for pulsar timing array experiments.

THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS. VII. IMPLICATIONS FROM THE NEARLY UNIVERSAL NATURE OF HORIZONTAL BRANCH DISCONTINUITIES

Energy Technology Data Exchange (ETDEWEB)

Brown, T. M.; Bellini, A.; Anderson, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Cassisi, S.; Pietrinferni, A. [INAF-Osservatorio Astronomico di Teramo, Via Mentore Maggini s.n.c., I-64100 Teramo (Italy); D’Antona, F. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio Catone, Roma (Italy); Salaris, M. [Astrophysics Research Institute,Liverpool John Moores University, Liverpool Science Park, IC2 Building, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Milone, A. P. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT, 2611 (Australia); Dalessandro, E. [Dipartimento di Fisica e Astronomia, Università degli Studi di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Piotto, G.; Ortolani, S.; Nardiello, D. [Dipartimento di Fisica e Astronomia “Galileo Galilei,”Università di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova (Italy); Renzini, A.; Bedin, L. R. [INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Sweigart, A. V. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sarajedini, A. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Aparicio, A., E-mail: tbrown@stsci.edu, E-mail: jayander@stsci, E-mail: bellini@stsci.edu, E-mail: cassisi@oa-teramo.inaf.it, E-mail: pietrinferni@oa-teramo.inaf.it, E-mail: dantona@oa-roma.inaf.it, E-mail: M.Salaris@ljmu.ac.uk, E-mail: milone@mso.anu.edu.au [Instituto de Astrofísica de Canarias. Calle Vía Láctea s/n. E38200 — La Laguna, Tenerife, Canary Islands (Spain)

2016-05-01

The UV-initiative Hubble Space Telescope Treasury survey of Galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch (HB). Using this large and homogeneous catalog of UV and blue photometry, we demonstrate that the HB exhibits discontinuities that are remarkably consistent in color (effective temperature). This consistency is apparent even among some of the most massive clusters hosting multiple distinct sub-populations (such as NGC 2808, ω Cen, and NGC 6715), demonstrating that these phenomena are primarily driven by atmospheric physics that is independent of the underlying population properties. However, inconsistencies arise in the metal-rich clusters NGC 6388 and NGC 6441, where the discontinuity within the blue HB (BHB) distribution shifts ∼1000–2000 K hotter. We demonstrate that this shift is likely due to a large helium enhancement in the BHB stars of these clusters, which in turn affects the surface convection and evolution of such stars. Our survey also increases the number of Galactic globular clusters known to host blue-hook stars (also known as late hot flashers) from 6 to 23 clusters. These clusters are biased toward the bright end of the globular cluster luminosity function, confirming that blue-hook stars tend to form in the most massive clusters with significant self-enrichment.

Using SysML for verification and validation planning on the Large Synoptic Survey Telescope (LSST)

Science.gov (United States)

Selvy, Brian M.; Claver, Charles; Angeli, George

2014-08-01

This paper provides an overview of the tool, language, and methodology used for Verification and Validation Planning on the Large Synoptic Survey Telescope (LSST) Project. LSST has implemented a Model Based Systems Engineering (MBSE) approach as a means of defining all systems engineering planning and definition activities that have historically been captured in paper documents. Specifically, LSST has adopted the Systems Modeling Language (SysML) standard and is utilizing a software tool called Enterprise Architect, developed by Sparx Systems. Much of the historical use of SysML has focused on the early phases of the project life cycle. Our approach is to extend the advantages of MBSE into later stages of the construction project. This paper details the methodology employed to use the tool to document the verification planning phases, including the extension of the language to accommodate the project's needs. The process includes defining the Verification Plan for each requirement, which in turn consists of a Verification Requirement, Success Criteria, Verification Method(s), Verification Level, and Verification Owner. Each Verification Method for each Requirement is defined as a Verification Activity and mapped into Verification Events, which are collections of activities that can be executed concurrently in an efficient and complementary way. Verification Event dependency and sequences are modeled using Activity Diagrams. The methodology employed also ties in to the Project Management Control System (PMCS), which utilizes Primavera P6 software, mapping each Verification Activity as a step in a planned activity. This approach leads to full traceability from initial Requirement to scheduled, costed, and resource loaded PMCS task-based activities, ensuring all requirements will be verified.

The Catalina Sky Survey for Near-Earth Objects

Science.gov (United States)

Christensen, E.

The Catalina Sky Survey (CSS) specializes in the detection of the closest transients in our transient universe: near-Earth objects (NEOs). CSS is the leading NEO survey program since 2005, with a discovery rate of 500-600 NEOs per year. This rate is set to substantially increase starting in 2014 with the deployment of wider FOV cameras at both survey telescopes, while a proposed 3-telescope system in Chile would provide a new and significant capability in the Southern Hemisphere beginning as early as 2015. Elements contributing to the success of CSS may be applied to other surveys, and include 1) Real-time processing, identification, and reporting of interesting transients; 2) Human-assisted validation to ensure a clean transient stream that is efficient to the limits of the system (˜ 1σ); 3) an integrated follow-up capability to ensure threshold or high-priority transients are properly confirmed and followed up. Additionally, the open-source nature of the CSS data enables considerable secondary science (i.e. CRTS), and CSS continues to pursue collaborations to maximize the utility of the data.

The Southern H ii Region Discovery Survey (SHRDS): Pilot Survey

Energy Technology Data Exchange (ETDEWEB)

Brown, C.; Dickey, John M. [School of Physical Sciences, Private Bag 37, University of Tasmania, Hobart, TAS, 7001 (Australia); Jordan, C. [International Centre for Radio Astronomy Research, Curtin University, Perth, WA, 6845 (Australia); Anderson, L. D.; Armentrout, W. P. [Department of Physics and Astronomy, West Virginia University, P.O. Box 6315, Morgantown, WV 26506 (United States); Balser, Dana S.; Wenger, Trey V. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22904 (United States); Bania, T. M. [Institute for Astrophysical Research, Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Dawson, J. R. [Department of Physics and Astronomy and MQ Research Centre in Astronomy, Astrophysics and Astrophotonics, Macquarie University, NSW, 2109 (Australia); Mc Clure-Griffiths, N. M. [Research School of Astronomy and Astrophysics, The Australian National University, Canberra ACT 2611 (Australia)

2017-07-01

The Southern H ii Region Discovery Survey is a survey of the third and fourth quadrants of the Galactic plane that will detect radio recombination line (RRL) and continuum emission at cm-wavelengths from several hundred H ii region candidates using the Australia Telescope Compact Array. The targets for this survey come from the WISE Catalog of Galactic H ii Regions and were identified based on mid-infrared and radio continuum emission. In this pilot project, two different configurations of the Compact Array Broad Band receiver and spectrometer system were used for short test observations. The pilot surveys detected RRL emission from 36 of 53 H ii region candidates, as well as seven known H ii regions that were included for calibration. These 36 recombination line detections confirm that the candidates are true H ii regions and allow us to estimate their distances.

The Southern H ii Region Discovery Survey (SHRDS): Pilot Survey

International Nuclear Information System (INIS)

Brown, C.; Dickey, John M.; Jordan, C.; Anderson, L. D.; Armentrout, W. P.; Balser, Dana S.; Wenger, Trey V.; Bania, T. M.; Dawson, J. R.; Mc Clure-Griffiths, N. M.

2017-01-01

The Southern H ii Region Discovery Survey is a survey of the third and fourth quadrants of the Galactic plane that will detect radio recombination line (RRL) and continuum emission at cm-wavelengths from several hundred H ii region candidates using the Australia Telescope Compact Array. The targets for this survey come from the WISE Catalog of Galactic H ii Regions and were identified based on mid-infrared and radio continuum emission. In this pilot project, two different configurations of the Compact Array Broad Band receiver and spectrometer system were used for short test observations. The pilot surveys detected RRL emission from 36 of 53 H ii region candidates, as well as seven known H ii regions that were included for calibration. These 36 recombination line detections confirm that the candidates are true H ii regions and allow us to estimate their distances.

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.

Remote secure observing for the Faulkes Telescopes

Science.gov (United States)

Smith, Robert J.; Steele, Iain A.; Marchant, Jonathan M.; Fraser, Stephen N.; Mucke-Herzberg, Dorothea

2004-09-01

Since the Faulkes Telescopes are to be used by a wide variety of audiences, both powerful engineering level and simple graphical interfaces exist giving complete remote and robotic control of the telescope over the internet. Security is extremely important to protect the health of both humans and equipment. Data integrity must also be carefully guarded for images being delivered directly into the classroom. The adopted network architecture is described along with the variety of security and intrusion detection software. We use a combination of SSL, proxies, IPSec, and both Linux iptables and Cisco IOS firewalls to ensure only authenticated and safe commands are sent to the telescopes. With an eye to a possible future global network of robotic telescopes, the system implemented is capable of scaling linearly to any moderate (of order ten) number of telescopes.

Single particle detecting telescope system

International Nuclear Information System (INIS)

Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.

1981-01-01

We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement

Building the Hubble Space Telescope

International Nuclear Information System (INIS)

O'dell, C.R.

1989-01-01

The development of the design for the Hubble Space Telescope (HST) is discussed. The HST optical system is described and illustrated. The financial and policy issues related to the development of the HST are considered. The actual construction of the HST optical telescope is examined. Also, consideration is given to the plans for the HST launch

Lee Sang Gak Telescope (LSGT): A Remotely Operated Robotic Telescope for Education and Research at Seoul National University

Science.gov (United States)

Im, Myungshin; Choi, Changsu; Kim, Kihyun

2015-08-01

We introduce the Lee Sang Gak Telescope (LSGT), a remotely operated, robotic 0.43-meter telescope. The telescope was installed at the Siding Spring Observatory, Australia, in 2014 October, to secure regular and exclusive access to the dark sky and excellent atmospheric conditions in the southern hemisphere from the Seoul National University (SNU) campus. Here, we describe the LSGT system and its performance, present example images from early observations, and discuss a future plan to upgrade the system. The use of the telescope includes (i) long-term monitoring observations of nearby galaxies, active galactic nuclei, and supernovae; (ii) rapid follow-up observations of transients such as gamma-ray bursts and gravitational wave sources; and (iii) observations for educational activities at SNU. Based on observations performed so far, we find that the telescope is capable of providing images to a depth of R=21.5 mag (point source detection) at 5-σ with 15 min total integration time under good obs-erving conditions.

The CTIO surveys for large redshift quasars

International Nuclear Information System (INIS)

Osmer, P.S.

1978-01-01

Lyman α emission in large redshift quasars is readily detectable on slitless spectrograms taken with an objective combination on the 4m telescope. This provides a new survey method, independent of color for finding radio-quiet quasars in large numbers. Surveys by Smith with the Curtis Schmidt and Hoag and Smith with the 4 m telescope, have produced more than 200 candidates with 1.5< z<3.5 and 16< m<21. Spectroscopic observations with the CTIO SIT vidicon system have been carried out for more than 50 of the candidates, with the result that the basic properties of the surveys are known. To date three 16th magnitude quasars with zapproximately2.2 and six quasars with 3.0< z<3.25 have been found. One of the most important uses of the surveys will be the determination of the surface and surface densities of large redshift quasars. A preliminary analysis of the data indicates that the space density of quasars is at least constant, if not increasing, over the interval 1.0< z<3.25. However, the Hoag-Smith sample has only one candidate with z<3.2.(Auth.)

The NASA Meter Class Autonomous Telescope: Ascension Island

Science.gov (United States)

Lederer, S. M.; Stansbery, E. G.; Cowardin, H. M.; Hickson, P.; Pace, L. F.; Abercromby, K. J.; Kervin, P. W.

2013-01-01

The Meter Class Autonomous Telescope (MCAT) is the newest optical sensor dedicated to NASA's mission to characterize the space debris environment. It is the successor to a series of optical telescopes developed and operated by the JSC Orbital Debris Program Office (ODPO) to monitor and assess the debris environment in (1) Low Earth Orbit (LEO), (2) Medium Earth Orbit (MEO), and (3) Geosynchronous Orbit (GEO), with emphasis on LEO and GEO altitudes. A joint NASA - Air Force Research Labs project, MCAT is a 1.3m optical telescope dedicated to debris research. Its optical path and sensor yield a large survey fence at the cutting edge of current detector performance. It has four primary operational observing modes, two of which were not computationally feasible a decade ago. Operations are supported by a sophisticated software suite that monitors clouds and weather conditions, and controls everything from data collection to dome rotation to processing tens of gigabytes of image data nightly. With fainter detection limits, precision detection, acquisition and tracking of targets, multi-color photometry, precision astrometry, automated re-acquisition capability, and the ability to process all data at the acquisition rate, MCAT is capable of producing and processing a volume and quality of data far in excess of any current (or prior) ODPO operations. This means higher fidelity population inputs and eliminating the multi-year backlog from acquisition-to-product typical of optical campaigns. All of this is possible given a suitable observing location. Ascension Island offers numerous advantages. As a British overseas territory with a US Air Force base presence, the necessary infrastructure and support already exists. It is located mid-way between Brazil and Africa at 7.93S latitude and 14.37 W longitude. With the Ground-based Electro-Optical Deep Space Surveillance (GEODSS) asset in Moron, Spain shutting down, this presents access to the sky from a unique latitude

LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) — The survey's science plan

International Nuclear Information System (INIS)

Deng Licai; Liu Chao; Chen Yuqin; Li Jing; Newberg Heidi Jo; Carlin, Jeffrey L.; Beers, Timothy C.; Chen Li; Hou Jinliang; Christlieb, Norbert; Grillmair, Carl J.; Guhathakurta, Puragra; Han Zhanwen; Wang Bo; Lee, Hsu-Tai; Lépine, Sébastien; Liu Xiaowei; Pan Kaike; Sellwood, J. A.; Wang Hongchi

2012-01-01

We describe the current plans for a spectroscopic survey of millions of stars in the Milky Way galaxy using the Guo Shou Jing Telescope (GSJT, formerly called the Large sky Area Multi-Object fiber Spectroscopic Telescope — LAMOST). The survey will obtain spectra for 2.5 million stars brighter than r < 19 during dark/grey time, and 5 million stars brighter than r < 17 or J < 16 on nights that are moonlit or have low transparency. The survey will begin in the fall of 2012, and will run for at least four years. The telescope's design constrains the optimal declination range for observations to 10° < δ < 50°, and site conditions lead to an emphasis on stars in the direction of the Galactic anticenter. The survey is divided into three parts with different target selection strategies: disk, anticenter, and spheroid. The resulting dataset will be used to study the merger history of the Milky Way, the substructure and evolution of the disks, the nature of the first generation of stars through identification of the lowest metallicity stars, and star formation through study of open clusters and OB associations. Detailed design of the LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) survey will be completed in summer 2012, after a review of the results of the pilot survey.

Carbon Fiber Mirror for a CubeSat Telescope

Science.gov (United States)

Kim, Young-Soo; Jang, Jeong Gyun; Kim, Jihun; Nam, Uk Won

2017-08-01

Telescope mirrors made by carbon fibers have been increasingly used especially for space applications, and they may replace the traditional glass mirrors. Glass mirrors are easy to fabricate, but needed to be carefully handled as they are brittle. Other materials have also been considered for telescope mirrors, such as metals, plastics, and liquids even. However glass and glass ceramics are still commonly and dominantly used.Carbon fiber has mainly been used for mechanical supports like truss structure and telescope tubes, as it is stiff and light-weight. It can also be a good material for telescope mirrors, as it has additional merits of non-brittle and very low thermal expansion. Therefore, carbon fiber mirror would be suitable for space telescopes which should endure the harsh vibration conditions during launch.A light-weight telescope made by carbon fiber has been designed for a small satellite which would have much less weight than conventional ones. In this poster, mirror materials are reviewed, and a design of carbon fiber telescope is presented and discussed.

A free market in telescope time?

Science.gov (United States)

Etherton, Jason; Steele, Iain A.; Mottram, Christopher J.

2004-09-01

As distributed systems are becoming more and more diverse in application there is a growing need for more intelligent resource scheduling. eSTAR Is a geographically distributed network of Grid-enabled telescopes, using grid middleware to provide telescope users with an authentication and authorisation method, allowing secure, remote access to such resources. The eSTAR paradigm is based upon this secure, single sign-on, giving astronomers or their agent proxies direct access to these telescopes. This concept, however, involves the complex issue of how to schedule observations stored within physically distributed media, on geographically distributed resources. This matter is complicated further by the varying degrees of constraints placed upon observations such as timeliness, atmospheric and meteorological conditions, and sky brightness to name a few. This paper discusses a free market approach to this scheduling problem, where astronomers are given credit, instead of time, from their respective TAGs to spend on telescopes as they see fit. This approach will ultimately provide a community-driven schedule, genuine indicators of the worth of specific telescope time and promote a more efficient use of that time, as well as demonstrating a 'survival of the fittest' type selection.

Transiting Exoplanet Survey Satellite (TESS)

Science.gov (United States)

Ricker, G. R.; Clampin, M.; Latham, D. W.; Seager, S.; Vanderspek, R. K.; Villasenor, J. S.; Winn, J. N.

2012-01-01

The Transiting Exoplanet Survey Satellite (TESS) will discover thousands of exoplanets in orbit around the brightest stars in the sky. In a two-year survey, TESS will monitor more than 500,000 stars for temporary drops in brightness caused by planetary transits. This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances. No ground-based survey can achieve this feat. A large fraction of TESS target stars will be 30-100 times brighter than those observed by Kepler satellite, and therefore TESS . planets will be far easier to characterize with follow-up observations. TESS will make it possible to study the masses, sizes, densities, orbits, and atmospheres of a large cohort of small planets, including a sample of rocky worlds in the habitable zones of their host stars. TESS will provide prime targets for observation with the James Webb Space Telescope (JWST), as well as other large ground-based and space-based telescopes of the future. TESS data will be released with minimal delay (no proprietary period), inviting immediate community-wide efforts to study the new planets. The TESS legacy will be a catalog of the very nearest and brightest main-sequence stars hosting transiting exoplanets, thus providing future observers with the most favorable targets for detailed investigations.

Ground-Based Telescope Parametric Cost Model

Science.gov (United States)

Stahl, H. Philip; Rowell, Ginger Holmes

2004-01-01

A parametric cost model for ground-based telescopes is developed using multi-variable statistical analysis, The model includes both engineering and performance parameters. While diameter continues to be the dominant cost driver, other significant factors include primary mirror radius of curvature and diffraction limited wavelength. The model includes an explicit factor for primary mirror segmentation and/or duplication (i.e.. multi-telescope phased-array systems). Additionally, single variable models based on aperture diameter are derived. This analysis indicates that recent mirror technology advances have indeed reduced the historical telescope cost curve.

WTS: A near-infrared transit survey

Directory of Open Access Journals (Sweden)

Hodgkin Simon

2013-04-01

Full Text Available The WFCAM Transit Survey is a transiting planet survey running on the United Kingdom Infrared Telescope targeting M dwarf stars in the near infrared. The survey has been operating since 2007 and gathering photometric time series of about 15000 M dwarf stars brighter than J = 17 mag. We identified and followed-up planet candidates from the most complete field and found two hot Jupiters around non-M dwarf hosts (WTS-1b & WTS-2b but found no planets around the M dwarfs.

Care of astronomical telescopes and accessories a manual for the astronomical observer and amateur telescope maker

CERN Document Server

Pepin, M Barlow

2005-01-01

Commercially-made astronomical telescopes are better and less expensive than ever before, and their optical and mechanical performance can be superb. When a good-quality telescope fails to perform as well as it might, the reason is quite probably that it needs a little care and attention! Here is a complete guide for anyone who wants to understand more than just the basics of astronomical telescopes and accessories, and how to maintain them in the peak of condition. The latest on safely adjusting, cleaning, and maintaining your equipment is combined with thoroughly updated methods from the old masters. Here, too, are details of choosing new and used optics and accessories, along with enhancements you can make to extend their versatility and useful lifetime. This book is for you. Really. Looking after an astronomical telescope isn't only for the experts - although there are some things that only an expert should attempt - and every serious amateur astronomer will find invaluable information here, gleaned from ...

Optimal survey strategies and predicted planet yields for the Korean microlensing telescope network

International Nuclear Information System (INIS)

Henderson, Calen B.; Gaudi, B. Scott; Skowron, Jan; Penny, Matthew T.; Gould, Andrew P.; Han, Cheongho; Nataf, David

2014-01-01

The Korean Microlensing Telescope Network (KMTNet) will consist of three 1.6 m telescopes each with a 4 deg 2 field of view (FoV) and will be dedicated to monitoring the Galactic Bulge to detect exoplanets via gravitational microlensing. KMTNet's combination of aperture size, FoV, cadence, and longitudinal coverage will provide a unique opportunity to probe exoplanet demographics in an unbiased way. Here we present simulations that optimize the observing strategy for and predict the planetary yields of KMTNet. We find preferences for four target fields located in the central Bulge and an exposure time of t exp = 120 s, leading to the detection of ∼2200 microlensing events per year. We estimate the planet detection rates for planets with mass and separation across the ranges 0.1 ≤ M p /M ⊕ ≤ 1000 and 0.4 ≤ a/AU ≤ 16, respectively. Normalizing these rates to the cool-planet mass function of Cassan et al., we predict KMTNet will be approximately uniformly sensitive to planets with mass 5 ≤ M p /M ⊕ ≤ 1000 and will detect ∼20 planets per year per dex in mass across that range. For lower-mass planets with mass 0.1 ≤ M p /M ⊕ < 5, we predict KMTNet will detect ∼10 planets per year. We also compute the yields KMTNet will obtain for free-floating planets (FFPs) and predict KMTNet will detect ∼1 Earth-mass FFP per year, assuming an underlying population of one such planet per star in the Galaxy. Lastly, we investigate the dependence of these detection rates on the number of observatories, the photometric precision limit, and optimistic assumptions regarding seeing, throughput, and flux measurement uncertainties.

GRANITE- A steroscopic imaging Chernkov telescope system

International Nuclear Information System (INIS)

Shubnell, M.; Akerlof, C.W.; Cawley, M.F.; Chantell, M.; Fegan, D.J.; Fennell, S.; O'Flaherty, K.S.; Freeman, S.; Frishman, D.; Gaidos, J.A.; Hagan, J.; Harris, K.; Hillas, A.M.; Kerrick, A.D.; Lamb, R.C.; Lappin, T.; Lawrence, M.A.; Levy, H.; Lewis, D.A.; Meyer, D.I.; Mohanty, G.; Punch, M.; Reynolds, P.T.; Rovero, A.C.; Sembroski, G.; Weaverdyck, C.; Weekes, T.C.; Whitaker, T.; Wilson, C.

1993-01-01

A second 10 meter class imaging telescope was constructed on Mt. Hopkins, Arizona, the site of the original 10 meter Whipple Cherenkov telescope. The twin telescope system with a 140 meter base line will allow both a reduction in the energy threshold and an improvement in the rejection of the hardonic background. The new telescope started operation in December 1991. With the final completion of the first installation stage (GRANITE I) during spring 92, it is now operating simultaneously with the orginal reflector. We describe in this paper design and construction of the new instrument and demonstrate the capability of the experiment to record coincident events

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

Trick or Treat and Telescopes

Science.gov (United States)

Buratti, Bonnie J.; Meinke, Bonnie K.; Schmude, Richard W.

2017-10-01

Based on an activity that DPS member Richard Schmude Jr. has been doing for years, with over 5000 children reached, DPS initiated in 2016 a pilot program entitled “Trick-or-Treat and Telescopes.” DPS encouraged its members to put out their telescopes during trick-or-treat time on Halloween, in their own lawns or in a neighbor’s lawn with better viewing (or more traffic). The program will be continued in 2017. This year should offer good viewing with a waxing gibbous moon and Saturn visible. The program was also advertised though the Night Sky Network, a consortium of astronomy clubs. The following website gives advice and connections to resources.https://dps.aas.org/education/trick-or-treat-and-telescopes acknowledged.

A search for radio pulsars and fast transients in M31 using the Westerbork Synthesis Radio Telescope

NARCIS (Netherlands)

Rubio-Herrera, E.; Stappers, B.W.; Hessels, J.W.T.; Braun, R.

2013-01-01

We present the results of the most sensitive and comprehensive survey yet undertaken for radio pulsars and fast transients in the Andromeda galaxy (M31) and its satellites, using the Westerbork Synthesis Radio Telescope (WSRT) at a central frequency of 328 MHz. We used the WSRT in a special

Project overview and update on WEAVE: the next generation wide-field spectroscopy facility for the William Herschel Telescope

NARCIS (Netherlands)

Dalton, Gavin; Trager, Scott; Abrams, Don Carlos; Bonifacio, Piercarlo; López Aguerri, J. Alfonso; Middleton, Kevin; Benn, Chris; Dee, Kevin; Sayède, Frédéric; Lewis, Ian; Pragt, Johan; Pico, Sergio; Walton, Nic; Rey, Juerg; Allende Prieto, Carlos; Peñate, José; Lhome, Emilie; Agócs, Tibor; Alonso, José; Terrett, David; Brock, Matthew; Gilbert, James; Ridings, Andy; Guinouard, Isabelle; Verheijen, Marc A.W.; Tosh, Ian; Rogers, Kevin; Steele, Iain; Stuik, Remko; Tromp, Neils; Jasko, Attila; Kragt, Jan; Lesman, Dirk; Mottram, Chris; Bates, Stuart; Gribbin, Frank; Rodriguez, Luis Fernando; Delgado, José M.; Martin, Carlos; Cano, Diego; Navarro, Ramón; Irwin, Mike; Lewis, Jim; Gonzalez Solares, Eduardo; O'Mahony, Neil; Bianco, Andrea; Zurita, Christina; ter Horst, Rik; Molinari, Emilio; Lodi, Marcello; Guerra, José; Vallenari, Antonella; Baruffolo, Andrea

We present an overview of and status report on the WEAVE next-generation spectroscopy facility for the William Herschel Telescope (WHT). WEAVE principally targets optical ground-based follow up of upcoming ground-based (LOFAR) and space-based (Gaia) surveys. WEAVE is a multi-object and multi-IFU

Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

Science.gov (United States)

Gardner, Jonathan P.

2009-01-01

The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts z greater than 6, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z greater than 10, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (less than 50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth-Sun Lagrange point. JWST 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. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems, and discuss recent progress in constructing the observatory.

Characterizing the Survey Strategy and Initial Orbit Determination Abilities of the NASA MCAT Telescope for Geosynchronous Orbital Debris Environmental Studies

Science.gov (United States)

Frith, J.; Barker, E.; Cowardin, H.; Buckalew, B.; Anz-Meador, P.; Lederer, S.

The National Aeronautics and Space Administration (NASA) Orbital Debris Program Office (ODPO) recently commissioned the Meter Class Autonomous Telescope (MCAT) on Ascension Island with the primary goal of obtaining population statistics of the geosynchronous (GEO) orbital debris environment. To help facilitate this, studies have been conducted using MCAT’s known and projected capabilities to estimate the accuracy and timeliness in which it can survey the GEO environment, including collected weather data and the proposed observational data collection cadence. To optimize observing cadences and probability of detection, on-going work using a simulated GEO debris population sampled at various cadences are run through the Constrained Admissible Region Multi Hypotheses Filter (CAR-MHF). The orbits computed from the results are then compared to the simulated data to assess MCAT’s ability to determine accurately the orbits of debris at various sample rates. The goal of this work is to discriminate GEO and near-GEO objects from GEO transfer orbit objects that can appear as GEO objects in the environmental models due to the short arc observation and an assumed circular orbit. The specific methods and results are presented here.

GASS: THE PARKES GALACTIC ALL-SKY SURVEY. I. SURVEY DESCRIPTION, GOALS, AND INITIAL DATA RELEASE

International Nuclear Information System (INIS)

McClure-Griffiths, N. M.; Calabretta, M. R.; Ford, H. Alyson; Newton-McGee, K.

2009-01-01

The Parkes Galactic All-Sky Survey (GASS) is a survey of Galactic atomic hydrogen (H I) emission in the Southern sky covering declinations δ ≤ 1 0 using the Parkes Radio Telescope. The survey covers 2π steradians with an effective angular resolution of ∼16', at a velocity resolution of 1.0 km s -1 , and with an rms brightness temperature noise of 57 mK. GASS is the most sensitive, highest angular resolution survey of Galactic H I emission ever made in the Southern sky. In this paper, we outline the survey goals, describe the observations and data analysis, and present the first-stage data release. The data product is a single cube at full resolution, not corrected for stray radiation. Spectra from the survey and other data products are publicly available online.

The readout and control system of the mid-size telescope prototype of the Cherenkov telescope array

International Nuclear Information System (INIS)

Oya, I; Anguner, O; Birsin, E; Schwanke, U; Behera, B; Melkumyan, D; Schmidt, T; Sternberger, R; Wegner, P; Wiesand, S; Fuessling, M

2014-01-01

The Cherenkov Telescope Array (CTA) is one of the major ground-based astronomy projects being pursued and will be the largest facility for ground-based y-ray observations ever built. CTA will consist of two arrays: one in the Northern hemisphere composed of about 20 telescopes, and the other one in the Southern hemisphere composed of about 100 telescopes, both arrays containing telescopes of different type and size. A prototype for the Mid-Size Telescope (MST) with a diameter of 12 m has been installed in Berlin and is currently being commissioned. This prototype is composed of a mechanical structure, a drive system and mirror facets mounted with powered actuators to enable active control. Five Charge-Coupled Device (CCD) cameras, and a wide set of sensors allow the evaluation of the performance of the instrument. The design of the control software is following concepts and tools under evaluation within the CTA consortium in order to provide a realistic test-bed for the middleware: 1) The readout and control system for the MST prototype is implemented with the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) distributed control middleware; 2) the OPen Connectivity-Unified Architecture (OPC UA) is used for hardware access; 3) the document oriented MongoDB database is used for an efficient storage of CCD images, logging and alarm information: and 4) MySQL and MongoDB databases are used for archiving the slow control monitoring data and for storing the operation configuration parameters. In this contribution, the details of the implementation of the control system for the MST prototype telescope are described.

The readout and control system of the mid-size telescope prototype of the Cherenkov Telescope Array

Science.gov (United States)

Oya, I.; Anguner, O.; Behera, B.; Birsin, E.; Fuessling, M.; Melkumyan, D.; Schmidt, T.; Schwanke, U.; Sternberger, R.; Wegner, P.; Wiesand, S.; Cta Consortium,the

2014-06-01

The Cherenkov Telescope Array (CTA) is one of the major ground-based astronomy projects being pursued and will be the largest facility for ground-based y-ray observations ever built. CTA will consist of two arrays: one in the Northern hemisphere composed of about 20 telescopes, and the other one in the Southern hemisphere composed of about 100 telescopes, both arrays containing telescopes of different type and size. A prototype for the Mid-Size Telescope (MST) with a diameter of 12 m has been installed in Berlin and is currently being commissioned. This prototype is composed of a mechanical structure, a drive system and mirror facets mounted with powered actuators to enable active control. Five Charge-Coupled Device (CCD) cameras, and a wide set of sensors allow the evaluation of the performance of the instrument. The design of the control software is following concepts and tools under evaluation within the CTA consortium in order to provide a realistic test-bed for the middleware: 1) The readout and control system for the MST prototype is implemented with the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) distributed control middleware; 2) the OPen Connectivity-Unified Architecture (OPC UA) is used for hardware access; 3) the document oriented MongoDB database is used for an efficient storage of CCD images, logging and alarm information: and 4) MySQL and MongoDB databases are used for archiving the slow control monitoring data and for storing the operation configuration parameters. In this contribution, the details of the implementation of the control system for the MST prototype telescope are described.

The Chrysalis Opens? Photometry from the η Carinae Hubble Space Telescope Treasury Project, 2002-2006

Science.gov (United States)

Martin, J. C.; Davidson, Kris; Koppelman, M. D.

2006-12-01

During the past decade η Car has brightened markedly, possibly indicating a change of state. Here we summarize photometry gathered by the Hubble Space Telescope (HST) as part of the HST Treasury Project on this object. Our data include Space Telescope Imaging Spectrograph (STIS) CCD acquisition images, Advanced Camera for Surveys HRC images in four filters, and synthetic photometry in flux-calibrated STIS spectra. The HST's spatial resolution allows us to examine the central star separate from the bright circumstellar ejecta. Its apparent brightness continued to increase briskly during 2002-2006, especially after the mid-2003 spectroscopic event. If this trend continues, the central star will soon become brighter than its ejecta, quite different from the state that existed only a few years ago. One precedent may be the rapid change observed in 1938-1953. We conjecture that the star's mass-loss rate has been decreasing throughout the past century. This research was conducted as part of the η Car Hubble Space Telescope Treasury project via grant GO-9973 from the Space Telescope Science Institute. HST is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Some of the data presented in this paper were obtained from the Multimission Archive at the Space Telescope Science Institute (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NAG5-7584 and by other grants and contracts.

Design and development of telescope control system and software for the 50/80 cm Schmidt telescope

Science.gov (United States)

Kumar, T. S.; Banavar, R. N.

2012-09-01

In this paper, we describe the details of telescope controller design for the 50/80 cm Schmidt telescope at the Aryabhatta Research Institute of observational sciencES. The GUI based software for commanding the telescope is developed in Visual C++. The hardware architecture features a distributed network of microcontrollers over CAN. The basic functionality can also be implemented using the dedicated RS232 port per board. The controller is able to perform with negligible rms velocity errors. At fine speeds limit cycles are exhibited due to nonlinear friction. At speeds over 3.90 × 10-02 radians/sec, the PI controller performs with peak errors less than 1%.

Simulation and track reconstruction for beam telescopes

CERN Document Server

Maqbool, Salman

2017-01-01

Beam telescopes are used for testing new detectors under development. Sensors are placed and a particle beam is passed through them. To test these novel detectors and determine their properties, the particle tracks need to be reconstructed from the known detectors in the telescope. Based on the reconstructed track, it’s predicted hits on the Device under Test (DUT) are compared with the actual hits on the DUT. Several methods exist for track reconstruction, but most of them don’t account for the effects of multiple scattering. General Broken Lines is one such algorithm which incorporates these effects during reconstruction. The aim of this project was to simulate the beam telescope and extend the track reconstruction framework for the FE-I4 telescope, which takes these effects into account. Section 1 introduces the problem, while section 2 focuses on beam telescopes. This is followed by the Allpix2 simulation framework in Section 3. And finally, Section 4 introduces the Proteus track reconstruction framew...

Simulation and Track Reconstruction for Beam Telescopes

CERN Document Server

Maqbool, Salman

2017-01-01

Beam telescopes are an important tool to test new detectors under development in a particle beam. To test these novel detectors and determine their properties, the particle tracks need to be reconstructed from the known detectors in the telescope. Based on the reconstructed track, its predicted position on the Device under Test (DUT) are compared with the actual hits on the DUT. Several methods exist for track reconstruction, but most of them do not account for the effects of multiple scattering. General Broken Lines is one such algorithm which incorporates these effects during reconstruction. The aim of this project was to simulate the beam telescope and extend the track reconstruction framework for the FE-I4 telescope, which takes these effects into account. Section 1 introduces the problem, while section 2 focuses on beam telescopes. This is followed by the Allpix2 simulation framework in Section 3. And finally, Section 4 introduces the Proteus track reconstruction framework along with the General Broken ...

Information and Communications Technology (ICT) Infrastructure for the ASTRI SST-2M telescope prototype for the Cherenkov Telescope Array

Science.gov (United States)

Gianotti, F.; Tacchini, A.; Leto, G.; Martinetti, E.; Bruno, P.; Bellassai, G.; Conforti, V.; Gallozzi, S.; Mastropietro, M.; Tanci, C.; Malaguti, G.; Trifoglio, M.

2016-08-01

The Cherenkov Telescope Array (CTA) represents the next generation of ground-based observatories for very high energy gamma-ray astronomy. The CTA will consist of two arrays at two different sites, one in the northern and one in the southern hemisphere. The current CTA design foresees, in the southern site, the installation of many tens of imaging atmospheric Cherenkov telescopes of three different classes, namely large, medium and small, so defined in relation to their mirror area; the northern hemisphere array would consist of few tens of the two larger telescope types. The Italian National Institute for Astrophysics (INAF) is developing the Cherenkov Small Size Telescope ASTRI SST- 2M end-to-end prototype telescope within the framework of the International Cherenkov Telescope Array (CTA) project. The ASTRI prototype has been installed at the INAF observing station located in Serra La Nave on Mt. Etna, Italy. Furthermore a mini-array, composed of nine of ASTRI telescopes, has been proposed to be installed at the Southern CTA site. Among the several different infrastructures belonging the ASTRI project, the Information and Communication Technology (ICT) equipment is dedicated to operations of computing and data storage, as well as the control of the entire telescope, and it is designed to achieve the maximum efficiency for all performance requirements. Thus a complete and stand-alone computer centre has been designed and implemented. The goal is to obtain optimal ICT equipment, with an adequate level of redundancy, that might be scaled up for the ASTRI mini-array, taking into account the necessary control, monitor and alarm system requirements. In this contribution we present the ICT equipment currently installed at the Serra La Nave observing station where the ASTRI SST-2M prototype will be operated. The computer centre and the control room are described with particular emphasis on the Local Area Network scheme, the computing and data storage system, and the

An afocal telescope configuration for the ESA ARIEL mission

Science.gov (United States)

Da Deppo, Vania; Focardi, Mauro; Middleton, Kevin; Morgante, Gianluca; Pascale, Enzo; Grella, Samuele; Pace, Emanuele; Claudi, Riccardo; Amiaux, Jérôme; Colomé Ferrer, Josep; Hunt, Thomas; Rataj, Miroslaw; Sierra-Roig, Carles; Ficai Veltroni, Iacopo; Eccleston, Paul; Micela, Giuseppina; Tinetti, Giovanna

2017-12-01

Atmospheric Remote-Sensing Infrared Exoplanet Large Survey (ARIEL) is a candidate as an M4 ESA mission to launch in 2026. During its 3.5 years of scientific operations, ARIEL will observe spectroscopically in the infrared (IR) a large population of known transiting planets in the neighbourhood of the solar system. ARIEL aims to give a breakthrough in the observation of exoplanet atmospheres and understanding of the physics and chemistry of these far-away worlds. ARIEL is based on a 1 m class telescope feeding a collimated beam into two separate instrument modules: a spectrometer module covering the waveband between 1.95 and 7.8 μm and a combined fine guidance system/visible photometer/NIR spectrometer. The telescope configuration is a classic Cassegrain layout used with an eccentric pupil and coupled to a tertiary off-axis paraboloidal mirror. To constrain the thermo-mechanically induced optical aberrations, the primary mirror (M1) temperature will be monitored and finely tuned using an active thermal control system based on thermistors and heaters. They will be switched on and off to maintain the M1 temperature within ± 1 K by the telescope control unit (TCU). The TCU is a payload electronics subsystem also responsible for the thermal control of the spectrometer module detectors as well as the secondary mirror mechanism and IR calibration source management. The TCU, being a slave subsystem of the instrument control unit, will collect the housekeeping data from the monitored subsystems and will forward them to the master unit. The latter will run the application software, devoted to the main spectrometer management and to the scientific data on-board processing.

The 60 Month All-Sky Burst Alert Telescope Survey of Active Galactic Nucleus and the Anisotropy of Nearby AGNs

Science.gov (United States)

Ajello, M.; Alexander, D. M.; Greiner, J.; Madejeski, G. M.; Gehrels, N.; Burlon, D.

2014-01-01

Surveys above 10 keV represent one of the best resources to provide an unbiased census of the population of active galactic nuclei (AGNs). We present the results of 60 months of observation of the hard X-ray sky with Swift/Burst Alert Telescope (BAT). In this time frame, BAT-detected (in the 15-55 keV band) 720 sources in an all-sky survey of which 428 are associated with AGNs, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of approx. 2 larger over similarly complete sets of AGNs. Our sample contains (at least) 15 bona fide Compton-thick AGNs and 3 likely candidates. Compton-thick AGNs represent approx. 5% of AGN samples detected above 15 keV. We use the BAT data set to refine the determination of the log N-log S of AGNs which is extremely important, now that NuSTAR prepares for launch, toward assessing the AGN contribution to the cosmic X-ray background. We show that the log N-log S of AGNs selected above 10 keV is now established to approx. 10% precision. We derive the luminosity function of Compton-thick AGNs and measure a space density of 7.9(+4.1/-2.9)× 10(exp -5)/cubic Mpc for objects with a de-absorbed luminosity larger than 2 × 10(exp 42) erg / s. As the BAT AGNs are all mostly local, they allow us to investigate the spatial distribution of AGNs in the nearby universe regardless of absorption. We find concentrations of AGNs that coincide spatially with the largest congregations of matter in the local (much < 85 Mpc) universe. There is some evidence that the fraction of Seyfert 2 objects is larger than average in the direction of these dense regions..

The TESS-HERMES survey data release 1

DEFF Research Database (Denmark)

Sharma, Sanjib; Stello, Dennis; Buder, Sven

2018-01-01

-Australian Telescope as part of the TESS-HERMES survey. Comparing our results with the TESS Input Catalogue (TIC) shows that the TIC is generally efficient in separating dwarfs and giants, but it has flagged more than 100 cool dwarfs (T-eff

Space Telescope maintenance and refurbishment

Science.gov (United States)

Trucks, H. F.

1983-01-01

The Space Telescope (ST) represents a new concept regarding spaceborne astronomical observatories. Maintenance crews will be brought to the orbital worksite to make repairs and replace scientific instruments. For major overhauls the telescope can be temporarily returned to earth with the aid of the Shuttle. It will, thus, be possible to conduct astronomical studies with the ST for two decades or more. The five first-generation scientific instruments used with the ST include a wide field/planetary camera, a faint object camera, a faint object spectrograph, a high resolution spectrograph, and a high speed photometer. Attention is given to the optical telescope assembly, the support systems module, aspects of mission and science operations, unscheduled maintenance, contingency orbital maintenance, planned on-orbit maintenance, ground maintenance, ground refurbishment, and ground logistics.

Eyes on the sky a spectrum of telescopes

CERN Document Server

Graham-Smith, Francis

2016-01-01

Astronomy is experiencing a golden age, with a new generation of innovative telescopes yielding a flood of information on the Universe. This book traces the development of telescopes from Galileo to the present day, and explains the basic principles of telescopes that operate in different parts of electromagnetic spectrum.

Recent Advances and Achievements at The Catalina Sky Survey

Science.gov (United States)

Leonard, Gregory J.; Christensen, Eric J.; Fuls, Carson; Gibbs, Alex; Grauer, Al; Johnson, Jess A.; Kowalski, Richard; Larson, Stephen M.; Matheny, Rose; Seaman, Rob; Shelly, Frank

2017-10-01

The Catalina Sky Survey (CSS) is a NASA-funded project fully dedicated to discover and track near-Earth objects (NEOs). Since its founding nearly 20 years ago CSS remains at the forefront of NEO surveys, and recent improvements in both instrumentation and software have increased both survey productivity and data quality. In 2016 new large-format (10K x 10K) cameras were installed on both CSS survey telescopes, the 1.5-m reflector and the 0.7-m Schmidt, increasing the field of view, and hence nightly sky coverage by 4x and 2.4x respectively. The new cameras, coupled with improvements in the reduction and detection pipelines, and revised sky-coverage strategies have yielded a dramatic upward trend of NEO discovery rates. CSS has also developed a custom adaptive queue manager for scheduling NEO follow-up astrometry using a remotely operated and recently renovated 1-m Cassegrain reflector telescope, improvements that have increased the production of follow-up astrometry for newly discovered NEOs and arc extensions for previously discovered objects by CSS and other surveys. Additionally, reprocessing of archival CSS data (which includes some 46 million individual astrometric measurements) through the new reduction and detection pipeline will allow for improved orbit determinations and increased arc extensions for hundreds of thousands of asteroids. Reprocessed data will soon feed into a new public archive of CSS images and catalog data products made available through NASA’s Planetary Data System (PDS). For the future, CSS is working towards improved NEO follow-up capabilities through a combination of access to larger telescopes, instrument upgrades and follow-up scheduling tools.

Cluster Mass Calibration at High Redshift: HST Weak Lensing Analysis of 13 Distant Galaxy Clusters from the South Pole Telescope Sunyaev-Zel’dovich Survey

Energy Technology Data Exchange (ETDEWEB)

Schrabback, T.; Applegate, D.; Dietrich, J. P.; Hoekstra, H.; Bocquet, S.; Gonzalez, A. H.; der Linden, A. von; McDonald, M.; Morrison, C. B.; Raihan, S. F.; Allen, S. W.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; Chiu, I.; Desai, S.; Foley, R. J.; de Haan, T.; High, F. W.; Hilbert, S.; Mantz, A. B.; Massey, R.; Mohr, J.; Reichardt, C. L.; Saro, A.; Simon, P.; Stern, C.; Stubbs, C. W.; Zenteno, A.

2017-10-14

We present an HST/Advanced Camera for Surveys (ACS) weak gravitational lensing analysis of 13 massive high-redshift (z(median) = 0.88) galaxy clusters discovered in the South Pole Telescope (SPT) Sunyaev-Zel'dovich Survey. This study is part of a larger campaign that aims to robustly calibrate mass-observable scaling relations over a wide range in redshift to enable improved cosmological constraints from the SPT cluster sample. We introduce new strategies to ensure that systematics in the lensing analysis do not degrade constraints on cluster scaling relations significantly. First, we efficiently remove cluster members from the source sample by selecting very blue galaxies in V - I colour. Our estimate of the source redshift distribution is based on Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) data, where we carefully mimic the source selection criteria of the cluster fields. We apply a statistical correction for systematic photometric redshift errors as derived from Hubble Ultra Deep Field data and verified through spatial cross-correlations. We account for the impact of lensing magnification on the source redshift distribution, finding that this is particularly relevant for shallower surveys. Finally, we account for biases in the mass modelling caused by miscentring and uncertainties in the concentration-mass relation using simulations. In combination with temperature estimates from Chandra we constrain the normalization of the mass-temperature scaling relation ln (E(z) M-500c/10(14)M(circle dot)) = A + 1.5ln (kT/7.2 keV) to A = 1.81(-0.14)(+0.24)(stat.)+/- 0.09(sys.), consistent with self-similar redshift evolution when compared to lower redshift samples. Additionally, the lensing data constrain the average concentration of the clusters to c(200c) = 5.6(-1.8)(+3.7).

Cluster mass calibration at high redshift: HST weak lensing analysis of 13 distant galaxy clusters from the South Pole Telescope Sunyaev-Zel'dovich Survey

Science.gov (United States)

Schrabback, T.; Applegate, D.; Dietrich, J. P.; Hoekstra, H.; Bocquet, S.; Gonzalez, A. H.; von der Linden, A.; McDonald, M.; Morrison, C. B.; Raihan, S. F.; Allen, S. W.; Bayliss, M.; Benson, B. A.; Bleem, L. E.; Chiu, I.; Desai, S.; Foley, R. J.; de Haan, T.; High, F. W.; Hilbert, S.; Mantz, A. B.; Massey, R.; Mohr, J.; Reichardt, C. L.; Saro, A.; Simon, P.; Stern, C.; Stubbs, C. W.; Zenteno, A.

2018-02-01

We present an HST/Advanced Camera for Surveys (ACS) weak gravitational lensing analysis of 13 massive high-redshift (zmedian = 0.88) galaxy clusters discovered in the South Pole Telescope (SPT) Sunyaev-Zel'dovich Survey. This study is part of a larger campaign that aims to robustly calibrate mass-observable scaling relations over a wide range in redshift to enable improved cosmological constraints from the SPT cluster sample. We introduce new strategies to ensure that systematics in the lensing analysis do not degrade constraints on cluster scaling relations significantly. First, we efficiently remove cluster members from the source sample by selecting very blue galaxies in V - I colour. Our estimate of the source redshift distribution is based on Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) data, where we carefully mimic the source selection criteria of the cluster fields. We apply a statistical correction for systematic photometric redshift errors as derived from Hubble Ultra Deep Field data and verified through spatial cross-correlations. We account for the impact of lensing magnification on the source redshift distribution, finding that this is particularly relevant for shallower surveys. Finally, we account for biases in the mass modelling caused by miscentring and uncertainties in the concentration-mass relation using simulations. In combination with temperature estimates from Chandra we constrain the normalization of the mass-temperature scaling relation ln (E(z)M500c/1014 M⊙) = A + 1.5ln (kT/7.2 keV) to A=1.81^{+0.24}_{-0.14}(stat.) {± } 0.09(sys.), consistent with self-similar redshift evolution when compared to lower redshift samples. Additionally, the lensing data constrain the average concentration of the clusters to c_200c=5.6^{+3.7}_{-1.8}.

ANTARES : The first undersea neutrino telescope

NARCIS (Netherlands)

Ageron, M.; Aguilar, J. A.; Al Samarai, I.; Albert, A.; Ameli, F.; Andre, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Arnaud, K.; Aslanides, E.; Jesus, A. C. Assis; 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.; Carloganu, 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.; Compere, 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.; Galata, S.; Galeotti, S.; Gay, P.; Gensolen, F.; Giacomelli, G.; Gojak, C.; Gomez-Gonzalez, 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.; Hernandez-Rey, J. J.; Herold, B.; Hoessl, 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.; Lefevre, D.; Legou, T.; Lelaizant, G.; Leveque, 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.; Mazeas, 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.; Patioselitis, D.; Papaleo, R.; Pavalas, 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.; Rethore, 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.; Schoeck, F.; Schuller, J. -P.; Schuessler, 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.; Wijnker, G.; Wobbe, G.; de Wolf, E.; Yakovenko, Y.; Yepes, H.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zuniga, J.; van Wijk, R.

2011-01-01

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

Optimal networks of future gravitational-wave telescopes

Science.gov (United States)

Raffai, Péter; Gondán, László; Heng, Ik Siong; Kelecsényi, Nándor; Logue, Josh; Márka, Zsuzsa; Márka, Szabolcs

2013-08-01

We aim to find the optimal site locations for a hypothetical network of 1-3 triangular gravitational-wave telescopes. We define the following N-telescope figures of merit (FoMs) and construct three corresponding metrics: (a) capability of reconstructing the signal polarization; (b) accuracy in source localization; and (c) accuracy in reconstructing the parameters of a standard binary source. We also define a combined metric that takes into account the three FoMs with practically equal weight. After constructing a geomap of possible telescope sites, we give the optimal 2-telescope networks for the four FoMs separately in example cases where the location of the first telescope has been predetermined. We found that based on the combined metric, placing the first telescope to Australia provides the most options for optimal site selection when extending the network with a second instrument. We suggest geographical regions where a potential second and third telescope could be placed to get optimal network performance in terms of our FoMs. Additionally, we use a similar approach to find the optimal location and orientation for the proposed LIGO-India detector within a five-detector network with Advanced LIGO (Hanford), Advanced LIGO (Livingston), Advanced Virgo, and KAGRA. We found that the FoMs do not change greatly in sites within India, though the network can suffer a significant loss in reconstructing signal polarizations if the orientation angle of an L-shaped LIGO-India is not set to the optimal value of ˜58.2°( + k × 90°) (measured counterclockwise from East to the bisector of the arms).

Active control of the Chinese Giant Solar Telescope

Science.gov (United States)

Dai, Yichun; Yang, Dehua; Jin, Zhenyu; Liu, Zhong; Qin, Wei

2014-07-01

The Chinese Giant Solar Telescope (CGST) is the next generation solar telescope of China with diameter of 8 meter. The unique feature of CGST is that its primary is a ring, which facilitates the polarization detection and thermal control. In its present design and development phase, two primary mirror patterns are considered. For one thing, the primary mirror is expected to construct with mosaic mirror with 24 trapezoidal (or petal) segments, for another thing, a monolithic mirror is also a candidate for its primary mirror. Both of them depend on active control technique to maintain the optical quality of the ring mirror. As a solar telescope, the working conditions of the CGST are quite different from those of the stellar telescopes. To avoid the image deterioration due to the mirror seeing and dome seeing, especially in the case of the concentration of flux in a solar telescope, large aperture solar projects prefer to adopt open telescopes and open domes. In this circumstance, higher wind loads act on the primary mirror directly, which will cause position errors and figure errors of the primary with matters worse than those of the current 10-meter stellar telescopes with dome protect. Therefore, it gives new challenges to the active control capability, telescope structure design, and wind shielding design. In this paper, the study progress of active control of CGST for its mosaic and monolithic mirror are presented, and the wind effects on such two primary mirrors are also investigated.

Managing Astronomy Research Data: Data Practices in the Sloan Digital Sky Survey and Large Synoptic Survey Telescope Projects

Science.gov (United States)

Sands, Ashley Elizabeth

2017-01-01

Ground-based astronomy sky surveys are massive, decades-long investments in scientific data collection. Stakeholders expect these datasets to retain scientific value well beyond the lifetime of the sky survey. However, the necessary investments in knowledge infrastructures for managing sky survey data are not yet in place to ensure the long-term…

The WFCAM Transit Survey

Directory of Open Access Journals (Sweden)

Hodgkin S.

2011-02-01

Full Text Available The WFCAM Transit Survey (WTS has been obtaining data on the United Kingdom Infrared Telescope since 2007. The WTS targets about 8,000 M dwarfs over several square degrees of sky, and aims to find low-mass eclipsing binaries and planets, down to the size of the Earth, transiting M dwarf stars with periods up to a few days.

Shape accuracy requirements on starshades for large and small apertures

Science.gov (United States)

Shaklan, Stuart B.; Marchen, Luis; Cady, Eric

2017-09-01

Starshades have been designed to work with large and small telescopes alike. With smaller telescopes, the targets tend to be brighter and closer to the Solar System, and their putative planetary systems span angles that require starshades with radii of 10-30 m at distances of 10s of Mm. With larger apertures, the light-collecting power enables studies of more numerous, fainter systems, requiring larger, more distant starshades with radii >50 m at distances of 100s of Mm. Characterization using infrared wavelengths requires even larger starshades. A mitigating approach is to observe planets between the petals, where one can observe regions closer to the star but with reduced throughput and increased instrument scatter. We compare the starshade shape requirements, including petal shape, petal positioning, and other key terms, for the WFIRST 26m starshade and the HABEX 72 m starshade concepts, over a range of working angles and telescope sizes. We also compare starshades having rippled and smooth edges and show that their performance is nearly identical.

EUSO-TA prototype telescope

Energy Technology Data Exchange (ETDEWEB)

Bisconti, Francesca, E-mail: francesca.bisconti@kit.edu

2016-07-11

EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

EUSO-TA prototype telescope

Science.gov (United States)

Bisconti, Francesca; JEM-EUSO Collaboration

2016-07-01

EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

Survey for C-Band High Spectral Lines with the Arecibo Telescope

Science.gov (United States)

Tan, Wei Siang

High-mass stars have masses greater than 8 solar masses and are the main source of heavy elements such as iron in the interstellar medium. This type of stars form in giant molecular clouds. Studying the molecular environment in star-forming regions is crucial to understand the physical structure and conditions that lead to the formation of high-mass stars. This thesis presents observations conducted with the 305m Arecibo Telescope in Puerto Rico of twelve high-mass star forming regions. Every source was observed in multiple transitions of molecular species including CH, CH3OH, H2CS, and OH lines, and a radio recombination line. The observations were conducted with the C-Band High receiver of the Arecibo Telescope in the frequency range of 6.0 to 7.4GHz. The goals of the observations were to investigate the detectability of different molecular species (including new possible molecular masers) and obtain high sensitivity observations of the 6.7GHz CH3OH line to detect absorption and use it as a probe of the kinematics of the molecular material with respect to the ionized gas. Among the results of the observations, we report detection of 6.7GHz CH3OH masers toward nine regions, OH masers toward five sources, 6.7GHz CH3OH absorption toward four sources (including tentative detections), and detection of H2CS toward the star forming region G34.26+0.15. We also found a variable and recurrent 6.7GHz CH3OH maser in G45.12+0.13. The 6.7GHz CH 3OH and 6278.65MHz H2CS absorption lines were modeled using the radiative transfer code RADEX to investigate the physical conditions of the molecular clouds responsible for the absorption lines. Our analysis of the absorption lines supports the interpretation that the spectral lines are tracing molecular envelopes of HII regions. In the case of 6.7GHz CH 3OH absorption, our results and data from an extensive literature review indicate that absorption is rare, but that a population of 6.7GHz CH 3OH absorbers may be present at levels

Development of the quality control system of the readout electronics for the large size telescope of the Cherenkov Telescope Array observatory

Science.gov (United States)

Konno, Y.; Kubo, H.; Masuda, S.; Paoletti, R.; Poulios, S.; Rugliancich, A.; Saito, T.

2016-07-01

The Cherenkov Telescope Array (CTA) is the next generation VHE γ-ray observatory which will improve the currently available sensitivity by a factor of 10 in the range 100 GeV to 10 TeV. The array consists of different types of telescopes, called large size telescope (LST), medium size telescope (MST) and small size telescope (SST). A LST prototype is currently being built and will be installed at the Observatorio Roque de los Muchachos, island of La Palma, Canary islands, Spain. The readout system for the LST prototype has been designed and around 300 readout boards will be produced in the coming months. In this note we describe an automated quality control system able to measure basic performance parameters and quickly identify faulty boards.

EDUCATIONAL ASTRONOMICAL OBSERVATIONS ON REMOTE ACCESS TELESCOPES

Directory of Open Access Journals (Sweden)

Ivan P. Kriachko

2016-01-01

Full Text Available The purpose of this article is to show the way of overcoming one of the major problems of astronomy teaching methods in upper secondary school – organization of educational astronomical observations. Nowadays it became possible to perform such observations on remote access telescopes. By using up-to-date informational and communicational technologies, having an opportunity to work with robotic telescopes allows us to organize a unique cognitive and research oriented activities for students while conducting their specialized astronomical studies. Below here is given a brief description of the most significant robotic telescopes and the way of the usage of open remote access telescopic network which was created by professors and scientists of Harvard-Smithsonian Center for Astrophysics, USA.

Multi-Epoch Hubble Space Telescope Observations of IZw18 : Characterization of Variable Stars at Ultra-Low Metallicities

NARCIS (Netherlands)

Fiorentino, G.; Ramos, R. Contreras; Clementini, G.; Marconi, M.; Musella, I.; Aloisi, A.; Annibali, F.; Saha, A.; Tosi, M.; van der Marel, R. P.

2010-01-01

Variable stars have been identified for the first time in the very metal-poor blue compact dwarf galaxy IZw18, using deep multi-band (F606W, F814W) time-series photometry obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope. We detected 34 candidate variable stars in the

Development of a SiPM Camera for a Schwarzschild-Couder Cherenkov Telescope for the Cherenkov Telescope Array

CERN Document Server

Otte, A N; Dickinson, H.; Funk, S.; Jogler, T.; Johnson, C.A.; Karn, P.; Meagher, K.; Naoya, H.; Nguyen, T.; Okumura, A.; Santander, M.; Sapozhnikov, L.; Stier, A.; Tajima, H.; Tibaldo, L.; Vandenbroucke, J.; Wakely, S.; Weinstein, A.; Williams, D.A.

2015-01-01

We present the development of a novel 11328 pixel silicon photomultiplier (SiPM) camera for use with a ground-based Cherenkov telescope with Schwarzschild-Couder optics as a possible medium-sized telescope for the Cherenkov Telescope Array (CTA). The finely pixelated camera samples air-shower images with more than twice the optical resolution of cameras that are used in current Cherenkov telescopes. Advantages of the higher resolution will be a better event reconstruction yielding improved background suppression and angular resolution of the reconstructed gamma-ray events, which is crucial in morphology studies of, for example, Galactic particle accelerators and the search for gamma-ray halos around extragalactic sources. Packing such a large number of pixels into an area of only half a square meter and having a fast readout directly attached to the back of the sensors is a challenging task. For the prototype camera development, SiPMs from Hamamatsu with through silicon via (TSV) technology are used. We give ...

The Falcon Telescope Network

Science.gov (United States)

Chun, F.; Tippets, R.; Dearborn, M.; Gresham, K.; Freckleton, R.; Douglas, M.

2014-09-01

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. Since the FTN has a general use purpose, objects of interest include satellites, astronomical research, and STEM support images. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA in the Cadet Space Operations Center. FTN users will be able to submit observational requests via a web interface. The requests will then be prioritized based on the type of user, the object of interest, and a user-defined priority. A network wide schedule will be developed every 24 hours and each FTN site will autonomously execute its portion of the schedule. After an observational request is completed, the FTN user will receive notification of collection and a link to the data. The Falcon Telescope Network is an ambitious endeavor, but demonstrates the cooperation that can be achieved by multiple educational institutions.

The Green Bank Third (GB3) survey of extragalactic radio sources at 1400 MHz

International Nuclear Information System (INIS)

Rys, S.; Machalski, J.

1987-01-01

The NRAO 91-m radio telescope in Green Bank, West Virginia was used to make a 1400-MHz sky survey covering an area of 0.0988 sr at declinations 70 deg ≤ δ 1950 < 76.8 deg with 10.1 x 10.5 arcmin resolution. This survey ends the series of smaller than 1-sr surveys made at 1400 MHz with that telescope and four-feed radiometer. A catalogue of 502 radiosources is presented, statistically complete to 112 mJy, which is about five times the rms noise and extragalactic confusion. The observations and data reduction are briefly summarized; the position and flux density errors are discussed. 13 refs., 2 tabs. (author)

Processing of data from innovative parabolic strip telescope.

Science.gov (United States)

Kosejk, Vladislav; Novy, J.; Chadzitaskos, Goce

2015-12-01

This paper presents an innovative telescope design based on the usage of a parabolic strip fulfilling the function of an objective. Isaac Newton was the first to solve the problem of chromatic aberration, which is caused by a difference in the refractive index of lenses. This problem was solved by a new kind of telescope with a mirror used as an objective. There are many different kinds of telescopes. The most basic one is the lens telescope. This type of a telescope uses a set of lenses. Another type is the mirror telescope, which employs the concave mirror, spherical parabolic mirror or hyperbolically shaped mirror as its objective. The lens speed depends directly on the surface of a mirror. Both types can be combined to form a telescope composed of at least two mirrors and a set of lenses. The light is reflected from the primary mirror to the secondary one and then to the lens system. This type is smaller-sized, with a respectively reduced lens speed. The telescope design presented in this paper uses a parabolic strip fulfilling the function of an objective. Observed objects are projected as lines in a picture plane. Each of the lines of a size equal to the size of the strip corresponds to the sum of intensities of the light coming perpendicular to the objective from an observed object. A series of pictures taken with a different rotation and processed by a special reconstruction algorithm is needed to get 2D pictures. The telescope can also be used for fast detection of objects. In this mode, the rotation and multiple pictures are not needed, just one picture in the focus of a mirror is required to be taken.

The All-Wavelength Extended Groth Strip International Survey(AEGIS) Data Sets

Energy Technology Data Exchange (ETDEWEB)

Davis, M.; Guhathakurta, P.; Konidaris, N.P.; Newman, J.A.; Ashby, M.L.N.; Biggs, A.D.; Barmby, P.; Bundy, K.; Chapman, S.C.; Coil,A.L.; Conselice, C.J.; Cooper, M.C.; Croton, D.J.; Eisenhardt, P.R.M.; Ellis, R.S.; Faber, S.M.; Fang, T.; Fazio, G.G.; Georgakakis, A.; Gerke,B.F.; Goss, W.M.; Gwyn, S.; Harker, J.; Hopkins, A.M.; Huang, J.-S.; Ivison, R.J.; Kassin, S.A.; Kirby, E.N.; Koekemoer, A.M.; Koo, D.C.; Laird, E.S.; Le Floc' h, E.; Lin, L.; Lotz, J.M.; Marshall, P.J.; Martin,D.C.; Metevier, A.J.; Moustakas, L.A.; Nandra, K.; Noeske, K.G.; Papovich, C.; Phillips, A.C.; Rich,R. M.; Rieke, G.H.; Rigopoulou, D.; Salim, S.; Schiminovich, D.; Simard, L.; Smail, I.; Small,T.A.; Weiner,B.J.; Willmer, C.N.A.; Willner, S.P.; Wilson, G.; Wright, E.L.; Yan, R.

2006-10-13

In this the first of a series of Letters, we present a description of the panchromatic data sets that have been acquired in the Extended Groth Strip region of the sky. Our survey, the All-wavelength Extended Groth Strip International Survey (AEGIS), is intended to study the physical properties and evolutionary processes of galaxies at z{approx}1. It includes the following deep, wide-field imaging data sets: Chandra/ACIS X-ray (0.5-10 keV), GALEX ultraviolet (1200-2500 Angstroms), CFHT/MegaCam Legacy Survey optical (3600-9000 Angstroms), CFHT/CFH12K optical (4500-9000 Angstroms), Hubble Space Telescope/ACS optical (4400-8500 Angstroms), Palomar/WIRC near-infrared (1.2-2.2 {micro}m), Spitzer/IRAC mid-infrared (3.6-8.0 {micro}m), Spitzer/MIPS far-infrared (24-70 {micro}m), and VLA radio continuum (6-20 cm). In addition, this region of the sky has been targeted for extensive spectroscopy using the DEIMOS spectrograph on the Keck II 10 m telescope. Our survey is compared to other large multiwavelength surveys in terms of depth and sky coverage.

The Next Generation Transit Survey (NGTS)

Science.gov (United States)

Wheatley, Peter J.; West, Richard G.; Goad, Michael R.; Jenkins, James S.; Pollacco, Don L.; Queloz, Didier; Rauer, Heike; Udry, Stéphane; Watson, Christopher A.; Chazelas, Bruno; Eigmüller, Philipp; Lambert, Gregory; Genolet, Ludovic; McCormac, James; Walker, Simon; Armstrong, David J.; Bayliss, Daniel; Bento, Joao; Bouchy, François; Burleigh, Matthew R.; Cabrera, Juan; Casewell, Sarah L.; Chaushev, Alexander; Chote, Paul; Csizmadia, Szilárd; Erikson, Anders; Faedi, Francesca; Foxell, Emma; Gänsicke, Boris T.; Gillen, Edward; Grange, Andrew; Günther, Maximilian N.; Hodgkin, Simon T.; Jackman, James; Jordán, Andrés; Louden, Tom; Metrailler, Lionel; Moyano, Maximiliano; Nielsen, Louise D.; Osborn, Hugh P.; Poppenhaeger, Katja; Raddi, Roberto; Raynard, Liam; Smith, Alexis M. S.; Soto, Maritza; Titz-Weider, Ruth

2018-04-01

We describe the Next Generation Transit Survey (NGTS), which is a ground-based project searching for transiting exoplanets orbiting bright stars. NGTS builds on the legacy of previous surveys, most notably WASP, and is designed to achieve higher photometric precision and hence find smaller planets than have previously been detected from the ground. It also operates in red light, maximizing sensitivity to late K and early M dwarf stars. The survey specifications call for photometric precision of 0.1 per cent in red light over an instantaneous field of view of 100 deg2, enabling the detection of Neptune-sized exoplanets around Sun-like stars and super-Earths around M dwarfs. The survey is carried out with a purpose-built facility at Cerro Paranal, Chile, which is the premier site of the European Southern Observatory (ESO). An array of twelve 20 cm f/2.8 telescopes fitted with back-illuminated deep-depletion CCD cameras is used to survey fields intensively at intermediate Galactic latitudes. The instrument is also ideally suited to ground-based photometric follow-up of exoplanet candidates from space telescopes such as TESS, Gaia and PLATO. We present observations that combine precise autoguiding and the superb observing conditions at Paranal to provide routine photometric precision of 0.1 per cent in 1 h for stars with I-band magnitudes brighter than 13. We describe the instrument and data analysis methods as well as the status of the survey, which achieved first light in 2015 and began full-survey operations in 2016. NGTS data will be made publicly available through the ESO archive.

Optimal networks of future gravitational-wave telescopes

International Nuclear Information System (INIS)

Raffai, Péter; Márka, Zsuzsa; Márka, Szabolcs; Gondán, László; Kelecsényi, Nándor; Heng, Ik Siong; Logue, Josh

2013-01-01

We aim to find the optimal site locations for a hypothetical network of 1–3 triangular gravitational-wave telescopes. We define the following N-telescope figures of merit (FoMs) and construct three corresponding metrics: (a) capability of reconstructing the signal polarization; (b) accuracy in source localization; and (c) accuracy in reconstructing the parameters of a standard binary source. We also define a combined metric that takes into account the three FoMs with practically equal weight. After constructing a geomap of possible telescope sites, we give the optimal 2-telescope networks for the four FoMs separately in example cases where the location of the first telescope has been predetermined. We found that based on the combined metric, placing the first telescope to Australia provides the most options for optimal site selection when extending the network with a second instrument. We suggest geographical regions where a potential second and third telescope could be placed to get optimal network performance in terms of our FoMs. Additionally, we use a similar approach to find the optimal location and orientation for the proposed LIGO-India detector within a five-detector network with Advanced LIGO (Hanford), Advanced LIGO (Livingston), Advanced Virgo, and KAGRA. We found that the FoMs do not change greatly in sites within India, though the network can suffer a significant loss in reconstructing signal polarizations if the orientation angle of an L-shaped LIGO-India is not set to the optimal value of ∼58.2°( + k × 90°) (measured counterclockwise from East to the bisector of the arms). (paper)

The Atacama Cosmology Telescope: Data Characterization and Map Making

Science.gov (United States)

Duenner, Rolando; Hasselfield, Matthew; Marriage, Tobias A.; Sievers, Jon; Acquaviva, Viviana; Addison, Graeme E.; Ade, Peter A. R.; Aguirre, Paula; Amiri, Mandana; Appel, John William;

KMTNET: A Network of 1.6 m Wide-Field Optical Telescopes Installed at Three Southern Observatories

Science.gov (United States)

Kim, Seung-Lee; Lee, Chung-Uk; Park, Byeong-Gon; Kim, Dong-Jin; Cha, Sang-Mok; Lee, Yongseok; Han, Cheongho; Chun, Moo-Young; Yuk, Insoo

2016-02-01

The Korea Microlensing Telescope Network (KMTNet) is a wide-field photometric system installed by the Korea Astronomy and Space Science Institute (KASI). Here, we present the overall technical specifications of the KMTNet observation system, test observation results, data transfer and image processing procedure, and finally, the KMTNet science programs. The system consists of three 1.6 m wide-field optical telescopes equipped with mosaic CCD cameras of 18k by 18k pixels. Each telescope provides a 2.0 by 2.0 square degree field of view. We have finished installing all three telescopes and cameras sequentially at the Cerro-Tololo Inter-American Observatory (CTIO) in Chile, the South African Astronomical Observatory (SAAO) in South Africa, and the Siding Spring Observatory (SSO) in Australia. This network of telescopes, which is spread over three different continents at a similar latitude of about -30 degrees, enables 24-hour continuous monitoring of targets observable in the Southern Hemisphere. The test observations showed good image quality that meets the seeing requirement of less than 1.0 arcsec in I-band. All of the observation data are transferred to the KMTNet data center at KASI via the international network communication and are processed with the KMTNet data pipeline. The primary scientific goal of the KMTNet is to discover numerous extrasolar planets toward the Galactic bulge by using the gravitational microlensing technique, especially earth-mass planets in the habitable zone. During the non-bulge season, the system is used for wide-field photometric survey science on supernovae, asteroids, and external galaxies.

Development of the quality control system of the readout electronics for the large size telescope of the Cherenkov Telescope Array observatory

Energy Technology Data Exchange (ETDEWEB)

Konno, Y.; Kubo, H.; Masuda, S. [Department of Physics, Graduate School of Science, Kyoto University, Kyoto (Japan); Paoletti, R.; Poulios, S. [SFTA Department, Physics Section, University of Siena and INFN, Siena (Italy); Rugliancich, A., E-mail: andrea.rugliancich@pi.infn.it [SFTA Department, Physics Section, University of Siena and INFN, Siena (Italy); Saito, T. [Department of Physics, Graduate School of Science, Kyoto University, Kyoto (Japan)

2016-07-11

The Cherenkov Telescope Array (CTA) is the next generation VHE γ-ray observatory which will improve the currently available sensitivity by a factor of 10 in the range 100 GeV to 10 TeV. The array consists of different types of telescopes, called large size telescope (LST), medium size telescope (MST) and small size telescope (SST). A LST prototype is currently being built and will be installed at the Observatorio Roque de los Muchachos, island of La Palma, Canary islands, Spain. The readout system for the LST prototype has been designed and around 300 readout boards will be produced in the coming months. In this note we describe an automated quality control system able to measure basic performance parameters and quickly identify faulty boards. - Highlights: • The Dragon Board is part of the DAQ of the LST Cherenkov telescope prototype. • We developed an automated quality control system for the Dragon Board. • We check pedestal, linearity, pulse shape and crosstalk values. • The quality control test can be performed on the production line.

The Hyper Suprime-Cam SSP Survey: Overview and survey design

Science.gov (United States)

Aihara, Hiroaki; Arimoto, Nobuo; Armstrong, Robert; Arnouts, Stéphane; Bahcall, Neta A.; Bickerton, Steven; Bosch, James; Bundy, Kevin; Capak, Peter L.; Chan, James H. H.; Chiba, Masashi; Coupon, Jean; Egami, Eiichi; Enoki, Motohiro; Finet, Francois; Fujimori, Hiroki; Fujimoto, Seiji; Furusawa, Hisanori; Furusawa, Junko; Goto, Tomotsugu; Goulding, Andy; Greco, Johnny P.; Greene, Jenny E.; Gunn, James E.; Hamana, Takashi; Harikane, Yuichi; Hashimoto, Yasuhiro; Hattori, Takashi; Hayashi, Masao; Hayashi, Yusuke; Hełminiak, Krzysztof G.; Higuchi, Ryo; Hikage, Chiaki; Ho, Paul T. P.; Hsieh, Bau-Ching; Huang, Kuiyun; Huang, Song; Ikeda, Hiroyuki; Imanishi, Masatoshi; Inoue, Akio K.; Iwasawa, Kazushi; Iwata, Ikuru; Jaelani, Anton T.; Jian, Hung-Yu; Kamata, Yukiko; Karoji, Hiroshi; Kashikawa, Nobunari; Katayama, Nobuhiko; Kawanomoto, Satoshi; Kayo, Issha; Koda, Jin; Koike, Michitaro; Kojima, Takashi; Komiyama, Yutaka; Konno, Akira; Koshida, Shintaro; Koyama, Yusei; Kusakabe, Haruka; Leauthaud, Alexie; Lee, Chien-Hsiu; Lin, Lihwai; Lin, Yen-Ting; Lupton, Robert H.; Mandelbaum, Rachel; Matsuoka, Yoshiki; Medezinski, Elinor; Mineo, Sogo; Miyama, Shoken; Miyatake, Hironao; Miyazaki, Satoshi; Momose, Rieko; More, Anupreeta; More, Surhud; Moritani, Yuki; Moriya, Takashi J.; Morokuma, Tomoki; Mukae, Shiro; Murata, Ryoma; Murayama, Hitoshi; Nagao, Tohru; Nakata, Fumiaki; Niida, Mana; Niikura, Hiroko; Nishizawa, Atsushi J.; Obuchi, Yoshiyuki; Oguri, Masamune; Oishi, Yukie; Okabe, Nobuhiro; Okamoto, Sakurako; Okura, Yuki; Ono, Yoshiaki; Onodera, Masato; Onoue, Masafusa; Osato, Ken; Ouchi, Masami; Price, Paul A.; Pyo, Tae-Soo; Sako, Masao; Sawicki, Marcin; Shibuya, Takatoshi; Shimasaku, Kazuhiro; Shimono, Atsushi; Shirasaki, Masato; Silverman, John D.; Simet, Melanie; Speagle, Joshua; Spergel, David N.; Strauss, Michael A.; Sugahara, Yuma; Sugiyama, Naoshi; Suto, Yasushi; Suyu, Sherry H.; Suzuki, Nao; Tait, Philip J.; Takada, Masahiro; Takata, Tadafumi; Tamura, Naoyuki; Tanaka, Manobu M.; Tanaka, Masaomi; Tanaka, Masayuki; Tanaka, Yoko; Terai, Tsuyoshi; Terashima, Yuichi; Toba, Yoshiki; Tominaga, Nozomu; Toshikawa, Jun; Turner, Edwin L.; Uchida, Tomohisa; Uchiyama, Hisakazu; Umetsu, Keiichi; Uraguchi, Fumihiro; Urata, Yuji; Usuda, Tomonori; Utsumi, Yousuke; Wang, Shiang-Yu; Wang, Wei-Hao; Wong, Kenneth C.; Yabe, Kiyoto; Yamada, Yoshihiko; Yamanoi, Hitomi; Yasuda, Naoki; Yeh, Sherry; Yonehara, Atsunori; Yuma, Suraphong

2018-01-01

Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2-m Subaru telescope on the summit of Mauna Kea in Hawaii. A team of scientists from Japan, Taiwan, and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg2 in five broad bands (grizy), with a 5 σ point-source depth of r ≈ 26. The Deep layer covers a total of 26 deg2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey.

The TACTIC atmospheric Cherenkov imaging telescope

International Nuclear Information System (INIS)

Koul, R.; Tickoo, A.K.; Kaul, S.K.; Kaul, S.R.; Kumar, N.; Yadav, K.K.; Bhatt, N.; Venugopal, K.; Goyal, H.C.; Kothari, M.; Chandra, P.; Rannot, R.C.; Dhar, V.K.; Koul, M.K.; Kaul, R.K.; Kotwal, S.; Chanchalani, K.; Thoudam, S.; Chouhan, N.; Sharma, M.; Bhattacharyya, S.; Sahayanathan, S.

2007-01-01

The TACTIC (TeV Atomospheric Cherenkov Telescope with Imaging Camera) γ-ray telescope, equipped with a light collector of area ∼9.5m 2 and a medium resolution imaging camera of 349 pixels, has been in operation at Mt. Abu, India, since 2001. This paper describes the main features of its various subsystems and its overall performance with regard to (a) tracking accuracy of its two-axes drive system, (b) spot size of the light collector, (c) back-end signal processing electronics and topological trigger generation scheme, (d) data acquisition and control system and (e) relative and absolute gain calibration methodology. Using a trigger field-of-view of 11x11 pixels (∼3.4 a tx3.4 a t), the telescope records a cosmic ray event rate of ∼2.5Hz at a typical zenith angle of 15 a t. Monte Carlo simulation results are also presented in the paper for comparing the expected performance of the telescope with actual observational results. The consistent detection of a steady signal from the Crab Nebula above ∼1.2TeV energy, at a sensitivity level of ∼5.0σ in ∼25h, along with excellent matching of its energy spectrum with that obtained by other groups, reassures that the performance of the TACTIC telescope is quite stable and reliable. Furthermore, encouraged by the detection of strong γ-ray signals from Mrk 501 (during 1997 and 2006 observations) and Mrk 421 (during 2001 and 2005-2006 observations), we believe that there is considerable scope for the TACTIC telescope to monitor similar TeV γ-ray emission activity from other active galactic nuclei on a long-term basis

A BROWN DWARF CENSUS FROM THE SIMP SURVEY

Energy Technology Data Exchange (ETDEWEB)

Robert, Jasmin; Gagné, Jonathan; Artigau, Étienne; Lafrenière, David; Nadeau, Daniel; Doyon, René; Malo, Lison; Albert, Loïc; Simard, Corinne [Département de physique and Observatoire du Mont-Mégantic, Université de Montréal, Montréal, QC H3C 3J7 (Canada); Gagliuffi, Daniella C. Bardalez; Burgasser, Adam J., E-mail: jasmin@astro.umontreal.ca [Center for Astrophysics and Space Sciences, University of California San Diego, 9500 Gilman Dr., Mail Code 0424, La Jolla, CA 92093 (United States)

2016-10-20

We have conducted a near-infrared (NIR) proper motion survey, the Sondage Infrarouge de Mouvement Propre, in order to discover field ultracool dwarfs (UCD) in the solar neighborhood. The survey was conducted by imaging ∼28% of the sky with the Caméra PAnoramique Proche-InfraRouge both in the southern hemisphere at the Cerro Tololo Inter-American Observatory 1.5 m telescope, and in the northern hemisphere at the Observatoire du Mont-Mégantic 1.6 m telescope and comparing the source positions from these observations with the Two Micron All-Sky Survey Point Source Catalog (2MASS PSC). Additional color criteria were used to further discriminate unwanted astrophysical sources. We present the results of an NIR spectroscopic follow-up of 169 M, L, and T dwarfs. Among the sources discovered are 2 young field brown dwarfs, 6 unusually red M and L dwarfs, 25 unusually blue M and L dwarfs, 2 candidate unresolved L+T binaries, and 24 peculiar UCDs. Additionally, we add 9 L/T transition dwarfs (L6–T4.5) to the already known objects.

A BROWN DWARF CENSUS FROM THE SIMP SURVEY

International Nuclear Information System (INIS)

Robert, Jasmin; Gagné, Jonathan; Artigau, Étienne; Lafrenière, David; Nadeau, Daniel; Doyon, René; Malo, Lison; Albert, Loïc; Simard, Corinne; Gagliuffi, Daniella C. Bardalez; Burgasser, Adam J.

2016-01-01

We have conducted a near-infrared (NIR) proper motion survey, the Sondage Infrarouge de Mouvement Propre, in order to discover field ultracool dwarfs (UCD) in the solar neighborhood. The survey was conducted by imaging ∼28% of the sky with the Caméra PAnoramique Proche-InfraRouge both in the southern hemisphere at the Cerro Tololo Inter-American Observatory 1.5 m telescope, and in the northern hemisphere at the Observatoire du Mont-Mégantic 1.6 m telescope and comparing the source positions from these observations with the Two Micron All-Sky Survey Point Source Catalog (2MASS PSC). Additional color criteria were used to further discriminate unwanted astrophysical sources. We present the results of an NIR spectroscopic follow-up of 169 M, L, and T dwarfs. Among the sources discovered are 2 young field brown dwarfs, 6 unusually red M and L dwarfs, 25 unusually blue M and L dwarfs, 2 candidate unresolved L+T binaries, and 24 peculiar UCDs. Additionally, we add 9 L/T transition dwarfs (L6–T4.5) to the already known objects.

Simulation of the Simbol-X telescope: imaging performance of a deformable x-ray telescope

Science.gov (United States)

Chauvin, Maxime; Roques, Jean-Pierre

2009-08-01

We have developed a simulation tool for a Wolter I telescope subject to deformations. The aim is to understand and predict the behavior of Simbol-X and other future missions (NuSTAR, Astro-H, IXO, ...). Our code, based on Monte-Carlo ray-tracing, computes the full photon trajectories up to the detector plane, along with the deformations. The degradation of the imaging system is corrected using metrology. This tool allows to perform many analyzes in order to optimize the configuration of any of these telescopes.

FACT. Bokeh alignment for Cherenkov telescopes

Energy Technology Data Exchange (ETDEWEB)

Mueller, Sebastian Achim [ETH Zurich (Switzerland); Buss, Jens [TU Dortmund (Germany)

2016-07-01

Imaging Atmospheric Cherenkov Telescopes (IACTs) need fast and large imaging optics to map the faint Cherenkov light emitted in cosmic ray air showers onto their image sensors. Segmented reflectors are inexpensive, lightweight and offer good image quality. However, alignment of the mirror facets remains a challenge. A good alignment is crucial in IACT observations to separate gamma rays from hadronic cosmic rays. We present a simple, yet extendable method, to align segmented reflectors using their Bokeh. Bokeh alignment does not need a star or good weather nights but can be done anytime, even during the day. Bokeh alignment optimizes the facet orientations by comparing the segmented reflector's Bokeh to a predefined template. The Bokeh is observed using the out of focus image of a nearby point like light source in a distance of about ten times the focal lengths. We introduce Bokeh alignment on segmented reflectors and present its use on the First Geiger-mode Avalanche Cherenkov Telescope (FACT) on Canary Island La Palma, as well as on the Cherenkov Telescope Array (CTA) Medium Size Telescope (MST) prototype in Berlin Adlershof.

Choosing and Using a Refracting Telescope

CERN Document Server

English, Neil

2011-01-01

The refracting telescope has a long and illustrious past. Here’s what the author says about early telescopes and today’s refractors: “Four centuries ago, a hitherto obscure Italian scientist turned a home-made spyglass towards the heavens. The lenses he used were awful by modern standards, inaccurately figured and filled with the scars of their perilous journey from the furnace to the finishing workshop. Yet, despite these imperfections, they allowed him to see what no one had ever seen before – a universe far more complex and dynamic than anyone had dared imagine. But they also proved endlessly useful in the humdrum of human affairs. For the first time ever, you could spy on your neighbor from a distance, or monitor the approach of a war-mongering army, thus deciding the fate of nations. “The refractor is without doubt the prince of telescopes. Compared with all other telescopic designs, the unobstructed view of the refractor enables it to capture the sharpest, highest contrast images and the wides...

Go-To Telescopes Under Suburban Skies

CERN Document Server

Monks, Neale

2010-01-01

For the last four centuries stargazers have turned their telescopes to the night skies to look at its wonders, but only in this age of computers has it become possible to let the telescope find for you the object you are looking for! So-called “go-to” telescopes are programmed with the locations of thousands of objects, including dazzling distant Suns, stunning neighboring galaxies, globular and open star clusters, the remnants of past supernovae, and many other breathtaking sights. This book does not tell you how to use your Go-to telescope. Your manual will help you do that. It tells you what to look for in the deep sky and why, and what equipment to best see it with. Organized broadly by what is best for viewing in the northern hemisphere in different seasons, Monks further divides the sights of each season into groupings such as “Showpiece Objects,” “Interesting Deep Sky Objects,” and “Obscure and Challenging Deep Sky Objects.” He also tells what objects are visible even in light-polluted ...

Telescoping cylindrical piezoelectric fiber composite actuator assemblies

Science.gov (United States)

Allison, Sidney G. (Inventor); Shams, Qamar A. (Inventor); Fox, Robert L. (Inventor); Fox, legal representative, Christopher L. (Inventor); Fox Chattin, legal representative, Melanie L. (Inventor)

2010-01-01

A telescoping actuator assembly includes a plurality of cylindrical actuators in a concentric arrangement. Each cylindrical actuator is at least one piezoelectric fiber composite actuator having a plurality of piezoelectric fibers extending parallel to one another and to the concentric arrangement's longitudinal axis. Each cylindrical actuator is coupled to concentrically-adjacent ones of the cylindrical actuators such that the plurality of cylindrical actuators can experience telescopic movement. An electrical energy source coupled to the cylindrical actuators applies actuation energy thereto to generate the telescopic movement.

THE EXTENDED HUBBLE SPACE TELESCOPE SUPERNOVA SURVEY: THE RATE OF CORE COLLAPSE SUPERNOVAE TO z {approx} 1

Energy Technology Data Exchange (ETDEWEB)

Dahlen, Tomas; Riess, Adam G. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Strolger, Louis-Gregory [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY 42101 (United States); Mattila, Seppo; Kankare, Erkki [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Vaeisaelaentie 20, FI-21500 Piikkioe (Finland); Mobasher, Bahram, E-mail: dahlen@stsci.edu [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)

2012-09-20

We use a sample of 45 core collapse supernovae detected with the Advanced Camera for Surveys on board the Hubble Space Telescope to derive the core collapse supernova rate in the redshift range 0.1 < z < 1.3. In redshift bins centered on (z) = 0.39, (z) = 0.73, and (z) = 1.11, we find rates of 3.00{sup +1.28}{sub -0.94} {sup +1.04}{sub -0.57}, 7.39{sup +1.86}{sub -1.52} {sup +3.20}{sub -1.60}, and 9.57{sup +3.76}{sub -2.80} {sup +4.96}{sub -2.80}, respectively, given in units of yr{sup -1} Mpc{sup -3} 10{sup -4} h {sup 3}{sub 70}. The rates have been corrected for host galaxy extinction, including supernovae missed in highly dust-enshrouded environments in infrared bright galaxies. The first errors are statistical while the second ones are the estimated systematic errors. We perform a detailed discussion of possible sources of systematic errors and note that these start to dominate over statistical errors at z > 0.5, emphasizing the need to better control the systematic effects. For example, a better understanding of the amount of dust extinction in the host galaxies and knowledge of the supernova luminosity function, in particular the fraction of faint M {approx}> -15 supernovae, is needed to better constrain the rates. When comparing our results with the core collapse supernova rate based on the star formation rate, we find a good agreement, consistent with the supernova rate following the star formation rate, as expected.

The Origins Space Telescope (OST)

Science.gov (United States)

Staguhn, Johannes

2018-01-01

The Origins Space Telescope is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies to be submitted by NASA Headquarters to the 2020 Astronomy and Astrophysics Decadal survey. The observatory will provide orders of magnitude improvements in sensitivity over prior missions, in particular for spectroscopy, enabling breakthrough science across astrophysics. The observatory will cover a wavelength range between 5 μm and 600 μm in order to enable the study of the formation of proto-planetary disks, detection of bio-signatures from extra-solar planet's atmospheres, characterization of the first galaxies in the universe, and many more. The five instruments that are currently studied are two imaging far-infrared spectrometers using incoherent detectors, providing up to R 10^5 spectral resolution, one far-infrared infrared heterodyne instrument for even higher spectral resolving powers, one far-infrared continuum imager and polarimeter, plus a mid-infrared coronagraph with imaging and spectroscopy mode. I will describe the scientific and technical capabilities of the observatory with focus on the expected synergies with AtLAST.

Neutrino telescopes sensitivity to dark matter

International Nuclear Information System (INIS)

Albuquerque, I.F.M.; Lamoureux, J.; Smoot, G.F.

2002-01-01

The nature of the dark matter of the Universe is yet unknown and most likely is connected with new physics. The search for its composition is underway through direct and indirect detection. Fundamental physical aspects such as energy threshold, geometry and location are taken into account to investigate proposed neutrino telescopes of km3 volume sensitivities to dark matter. These sensitivities are just sufficient to test a few weakly interacting massive particle scenarios. Telescopes of km3 volume, such as IceCube, can definitely discover or exclude superheavy (M>1010 GeV) strong interacting massive particles (simpzillas). Smaller neutrino telescopes such as ANTARES, AMANDA-II and NESTOR can probe a large region of simpzilla parameter space

The afocal telescope of the ESA ARIEL mission: analysis of the layout

Science.gov (United States)

Da Deppo, Vania; Middleton, Kevin; Focardi, Mauro; Morgante, Gianluca; Corso, Alain Jody; Pace, Emanuele; Claudi, Riccardo; Micela, Giuseppina

2017-09-01

ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is one of the three present candidates as an M4 ESA mission to be launched in 2026. During its foreseen 3.5 years operation, it will observe spectroscopically in the infrared a large population of known transiting planets in the neighborhood of the Solar System. The aim is to enable a deep understanding of the physics and chemistry of these exoplanets. ARIEL is based on a 1-m class telescope ahead of a suite of instruments: two spectrometer channels covering the band 1.95 to 7.8 μm and four photometric channels (two wide and two narrow band) in the range 0.5 to 1.9 μm. The ARIEL optical design is conceived as a fore-module common afocal telescope that will feed the spectrometer and photometric channels. The telescope optical design is based on an eccentric pupil two-mirror classic Cassegrain configuration coupled to a tertiary paraboloidal mirror. The temperature of the primary mirror (M1) will be monitored and finely tuned by means of an active thermal control system based on thermistors and heaters. They will be switched on and off to maintain the M1 temperature within ±1 K thanks to a proportional-integral-derivative (PID) controller implemented within the Telescope Control Unit (TCU), a Payload electronics subsystem mainly in charge of the active thermal control of the two detectors owning to the spectrometer. TCU will collect the housekeeping data of the controlled subsystems and will forward them to the spacecraft (S/C) by means of the Instrument Control Unit (ICU), the main Payload's electronic Unit linked to the S/C On Board Computer (OBC).

The Telescope: Outline of a Poetic History

Science.gov (United States)

Stocchi, M. P.

2011-06-01

Amongst the first editions of Galileo's books, only the Saggiatore has on its frontispiece the image of the telescope. Indeed, the telescope is not pictured on the very emphatic frontispieces of the other books in which Galileo was presenting and defending the results achieved by his celestial observations, such as the Sidereus Nuncius. Many contemporary scientists denied the reliability of the telescope, and some even refused to look into the eyepiece. In the 16th and 17th century, the lenses, mirrors, and optical devices of extraordinary complexity did not have the main task of leading to the objective truth but obtaining the deformation of the reality by means of amazing effects of illusion. The Baroque art and literature had the aim of surprising, and the artists gave an enthusiastic support to the telescope. The poems in praise of Galileo's telescopic findings were quite numerous, including Adone composed by Giovanni Battista Marino, one of the most renowned poets of the time. The Galilean discoveries were actually accepted by the poets as ideologically neutral contributions to the "wonder" in spite they were rejected or even condemned by the scientists, philosophers, and theologians.

Development and Performances of the Magic Telescope

Science.gov (United States)

Bastieri, D.; Bigongiari, C.; Dazzi, F.; Mariotti, M.; Moralejo, A.; Peruzzo, L.; Saggion, A.; Tonello, N.

2002-11-01

The MAGIC Collaboration is building an imaging Čerenkov telescope at La Palma site (2200 m a.s.l.), in the Canary Islands, to observe gamma rays in the hundred-GeV region. The MAGIC telescope, with its reflecting parabolic dish, 17 m in diameter, and a two-level pattern trigger designed to cope with severe trigger rates, is the Čerenkov telescope with the lowest envisaged energy threshold. Due to its lightweight alto-azimuthal mounting, MAGIC can be repositioned in less than 30 seconds, becoming the only detector, with an adequate effective area, capable to observe GRB phenomena above 30 GeV. MAGIC telescope is characterised by a 30 GeV energy threshold and a sensitivity of 6×l0-11 cm-2s-1 for a 5σ-detection in 50-hours of observation. In this report, some future scientific goals for MAGIC will be highlighted and the technical development for the main elements of the telescope will be detailed. Special emphasis will be given to the construction of the individual metallic mirrors which form the reflecting surface and the development of the fast pattern-recognition trigger.

A new concept of imaging system: telescope windows

Science.gov (United States)

Bourgenot, Cyril; Cowie, Euan; Young, Laura; Love, Gordon; Girkin, John; Courtial, Johannes

2018-02-01

A Telescope window is a novel concept of transformation-optics consisting of an array of micro-telescopes, in our configuration, of a Galilean type. When the array is considered as one multifaceted device, it acts as a traditional Galilean telescope with distinctive and attractive properties such as compactness and modularity. Each lenslet, can in principle, be independently designed for a specific optical function. In this paper, we report on the design, manufacture and prototyping, by diamond precision machining, of 2 concepts of telescope windows, and discuss both their performances and limitations with a view to use them as potential low vision aid devices to support patients with macular degeneration.

GISOT: a giant solar telescope

Science.gov (United States)

Hammerschlag, Robert H.; von der Lühe, Oskar F.; Bettonvil, Felix C.; Jägers, Aswin P.; Snik, Frans

2004-10-01

A concept is presented for an extremely large high-resolution solar telescope with an aperture of 11 m and diffraction limited for visual wavelengths. The structure of GISOT will be transparent to wind and placed on a transparent stiff tower. For efficient wind flushing, all optics, including the primary mirror, will be located above the elevation axis. The aperture will be of the order of 11 m, not rotatively symmetrical, but of an elongated shape with dimensions 11 x 4 m. It consists of a central on-axis 4 m mirror with on both sides 3 pieces of 2 m mirrors. The optical layout will be kept simple to guarantee quality and minimize stray light. A Coudé room for instruments is planned below the telescope. The telescope will not be housed in a dome-like construction, which interferes with the open principle. Instead the telescope will be protected by a foldable tent construction with a diameter of the order of 30 m, which doesn"t form any obstruction during observations, but can withstand the severe weather circumstances on mountain sites. Because of the nature of the solar scene, extremely high resolution in only one dimension is sufficient to solve many exciting problems in solar physics and in this respect the concept of GISOT is very promising.

Undergraduate Education with the WIYN 0.9-m Telescope

Science.gov (United States)

Pilachowski, Catherine A.

2017-01-01

Several models have been explored at Indiana University Bloomington for undergraduate student engagement in astronomy using the WIYN 0.9-m telescope at Kitt Peak. These models include individual student research projects using the telescope, student observations as part of an observational techniques course for majors, and enrichment activities for non-science majors in general education courses. Where possible, we arrange for students to travel to the telescope. More often, we are able to use simple online tools such as Skype and VNC viewers to give students an authentic observing experience. Experiences with the telescope motivate students to learn basic content in astronomy, including the celestial sphere, the electromagnetic spectrum, telescopes and detectors, the variety of astronomical objects, date reduction processes, image analysis, and color image creation and appreciation. The WIYN 0.9-m telescope is an essential tool for our program at all levels of undergraduate education

Weak maser emission of methyl formate toward Sagittarius B2(N) in the green bank telescope PRIMOS survey

Energy Technology Data Exchange (ETDEWEB)

Faure, A.; Wiesenfeld, L. [UJF-Grenoble 1/CNRS-INSU, Institut de Planétologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble F-38041 (France); Remijan, A. J. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Szalewicz, K. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)

2014-03-10

A non-LTE radiative transfer treatment of cis-methyl formate (HCOOCH{sub 3}) rotational lines is presented for the first time using a set of theoretical collisional rate coefficients. These coefficients have been computed in the temperature range 5-30 K by combining coupled-channel scattering calculations with a high accuracy potential energy surface for HCOOCH{sub 3}-He. The results are compared to observations toward the Sagittarius B2(N) molecular cloud using the publicly available PRIMOS survey from the Green Bank Telescope. A total of 49 low-lying transitions of methyl formate, with upper levels below 25 K, are identified. These lines are found to probe a presumably cold (∼30 K), moderately dense (∼10{sup 4} cm{sup –3}), and extended region surrounding Sgr B2(N). The derived column density of ∼4 × 10{sup 14} cm{sup –2} is only a factor of ∼10 larger than the column density of the trans conformer in the same source. Provided that the two conformers have the same spatial distribution, this result suggests that strongly non-equilibrium processes must be involved in their synthesis. Finally, our calculations show that all detected emission lines with a frequency below 30 GHz are (collisionally pumped) weak masers amplifying the continuum of Sgr B2(N). This result demonstrates the importance and generality of non-LTE effects in the rotational spectra of complex organic molecules at centimeter wavelengths.

Development in High-Density Cobra Fiber Positioners for the Subaru Telescope's Prime Focus Spectrometer

Science.gov (United States)

Fisher, Charles D.; Braun, David F.; Kaluzny, Joel V.; Seiffert, Mic D.; Dekany, Richard G.; Ellis, Richard S.; Smith, Roger S.

2012-01-01

The Prime Focus Spectrograph (PFS) is a fiber fed multi-object spectrometer for the Subaru Telescope that will conduct a variety of targeted surveys for studies of dark energy, galaxy evolution, and galactic archaeology. The key to the instrument is a high density array of fiber positioners placed at the prime focus of the Subaru Telescope. The system, nicknamed "Cobra", will be capable of rapidly reconfiguring the array of 2394 optical fibers to the image positions of astronomical targets in the focal plane with high accuracy. The system uses 2394 individual "SCARA robot" mechanisms that are 7.7mm in diameter and use 2 piezo-electric rotary motors to individually position each of the optical fibers within its patrol region. Testing demonstrates that the Cobra positioner can be moved to within 5 micrometers of an astronomical target in 6 move iterations with a success rate of 95%. The Cobra system is a key aspect of PFS that will enable its unprecedented combination of high-multiplex factor and observing efficiency on the Subaru telescope. The requirements, design, and prototyping efforts for the fiber positioner system for the PFS are described here as are the plans for modular construction, assembly, integration, functional testing, and performance validation.

Aplanatic telescopes based on Schwarzschild optical configuration: from grazing incidence Wolter-like x-ray optics to Cherenkov two-mirror normal incidence telescopes

Science.gov (United States)

Sironi, Giorgia

2017-09-01

At the beginning of XX century Karl Schwarzschild defined a method to design large-field aplanatic telescopes based on the use of two aspheric mirrors. The approach was then refined by Couder (1926) who, in order to correct for the astigmatic aberration, introduced a curvature of the focal plane. By the way, the realization of normal-incidence telescopes implementing the Schwarzschild aplanatic configuration has been historically limited by the lack of technological solutions to manufacture and test aspheric mirrors. On the other hand, the Schwarzschild solution was recovered for the realization of coma-free X-ray grazing incidence optics. Wolter-like grazing incidence systems are indeed free of spherical aberration, but still suffer from coma and higher order aberrations degrading the imaging capability for off-axis sources. The application of the Schwarzschild's solution to X-ray optics allowed Wolter to define an optical system that exactly obeys the Abbe sine condition, eliminating coma completely. Therefore these systems are named Wolter-Schwarzschild telescopes and have been used to implement wide-field X-ray telescopes like the ROSAT WFC and the SOHO X-ray telescope. Starting from this approach, a new class of X-ray optical system was proposed by Burrows, Burg and Giacconi assuming polynomials numerically optimized to get a flat field of view response and applied by Conconi to the wide field x-ray telescope (WFXT) design. The Schwarzschild-Couder solution has been recently re-discovered for the application to normal-incidence Cherenkov telescopes, thanks to the suggestion by Vassiliev and collaborators. The Italian Institute for Astrophysics (INAF) realized the first Cherenkov telescope based on the polynomial variation of the Schwarzschild configuration (the so-called ASTRI telescope). Its optical qualification was successfully completed in 2016, demonstrating the suitability of the Schwarzschild-like configuration for the Cherenkov astronomy requirements

Radio telescope control

CERN Document Server

Schraml, J

1972-01-01

An on-line computer control process developed for the 100-m radio telescope of the Max-Planck-Institut fur Radioastronomie in Bonn is described. The instrument is the largest fully steerable antenna in the world. Its operation started on May 31st 1972. It is controlled by a Ferranti Argus 500 on-line computer. The first part of the paper deals with the process itself, the radio telescope and its operation, and the demands resulting for the control program. The second part briefly describes the computer and its hardware. The final part introduces the architecture of the executive program in general, which has been tailored to meet the demands of the process and the hardware. The communication between the observer and the system, the format of data on magnetic tape and an on-line reduction of position measurements are considered. (0 refs).

The JCMT Telescope Management System

Science.gov (United States)

Tilanus, Remo P. J.; Jenness, Tim; Economou, Frossie; Cockayne, Steve

Established telescopes often face a challenge when trying to incorporate new software standards and utilities into their existing real-time control system. At the JCMT we have successfully added important new features such as a Relational Database (the Telescope Management System---TMS), an online data Archive, and WWW based utilities to an, in part, 10-year old system. The new functionality was added with remarkably few alterations to the existing system. We are still actively expanding and exploring these new capabilities.

THE ATACAMA COSMOLOGY TELESCOPE: DATA CHARACTERIZATION AND MAPMAKING

Energy Technology Data Exchange (ETDEWEB)

Duenner, Rolando; Aguirre, Paula; Barrientos, L. Felipe [Departamento de Astronomia y Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Hasselfield, Matthew; Amiri, Mandana; Battistelli, Elia S.; Burger, Bryce [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Marriage, Tobias A.; Acquaviva, Viviana; Das, Sudeep [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Sievers, Jon; Appel, John William [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Addison, Graeme E.; Calabrese, Erminia [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom); Ade, Peter A. R. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff CF24 3AA (United Kingdom); Bond, J. Richard [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Brown, Ben [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Chervenak, Jay [Code 553/665, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Devlin, Mark J.; Dicker, Simon R. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); and others

2013-01-01

We present a description of the data reduction and mapmaking pipeline used for the 2008 observing season of the Atacama Cosmology Telescope (ACT). The data presented here at 148 GHz represent 12% of the 90 TB collected by ACT from 2007 to 2010. In 2008 we observed for 136 days, producing a total of 1423 hr of data (11 TB for the 148 GHz band only), with a daily average of 10.5 hr of observation. From these, 1085 hr were devoted to an 850 deg{sup 2} stripe (11.2 hr by 9. Degree-Sign 1) centered on a declination of -52. Degree-Sign 7, while 175 hr were devoted to a 280 deg{sup 2} stripe (4.5 hr by 4. Degree-Sign 8) centered at the celestial equator. The remaining 163 hr correspond to calibration runs. We discuss sources of statistical and systematic noise, calibration, telescope pointing, and data selection. For the 148 GHz band, out of 1260 survey hours and 1024 detectors in the array, 816 hr and 593 effective detectors remain after data selection, yielding a 38% survey efficiency. The total sensitivity in 2008, determined from the noise level between 5 Hz and 20 Hz in the time-ordered data stream (TOD), is 32 {mu}K{radical}s in cosmic microwave background units. Atmospheric brightness fluctuations constitute the main contaminant in the data and dominate the detector noise covariance at low frequencies in the TOD. The maps were made by solving the least-squares problem using the Preconditioned Conjugate Gradient method, incorporating the details of the detector and noise correlations. Simulations, as well as cross-correlations with Wilkinson Microwave Anisotropy Probe sky maps on large angular scales, reveal that our maps are unbiased at multipoles l > 300. This paper accompanies the public release of the 148 GHz southern stripe maps from 2008. The techniques described here will be applied to future maps and data releases.

Development of Slewing Mirror Telescope Optical System for the UFFO-pathfinder

DEFF Research Database (Denmark)

Jeong, S.; Nam, J.W.; Ahn, K.-B.

2013-01-01

The Slewing Mirror Telescope (SMT) is the UV/optical telescope of UFFO-pathfinder. The SMT optical system is a Ritchey-Chrétien (RC) telescope of 100 mm diameter pointed by means of a gimbal-mounted flat mirror in front of the telescope. The RC telescope has a 17 × 17arcmin2 in Field of View and ...

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...

The UK Infrared Telescope M33 monitoring project - I. Variable red giant stars in the central square kiloparsec

Science.gov (United States)

Javadi, Atefeh; van Loon, Jacco Th.; Mirtorabi, Mohammad Taghi

2011-02-01

We have conducted a near-infrared monitoring campaign at the UK Infrared Telescope (UKIRT), of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. The most extensive data set was obtained in the K band with the UIST instrument for the central 4 × 4 arcmin2 (1 kpc2) - this contains the nuclear star cluster and inner disc. These data, taken during the period 2003-2007, were complemented by J- and H-band images. Photometry was obtained for 18 398 stars in this region; of these, 812 stars were found to be variable, most of which are asymptotic giant branch (AGB) stars. Our data were matched to optical catalogues of variable stars and carbon stars and to mid-infrared photometry from the Spitzer Space Telescope. In this first of a series of papers, we present the methodology of the variability survey and the photometric catalogue - which is made publicly available at the Centre de Données astronomiques de Strasbourg - and discuss the properties of the variable stars. The most dusty AGB stars had not been previously identified in optical variability surveys, and our survey is also more complete for these types of stars than the Spitzer survey.

Observations of Anomalous Refraction with Co-housed Telescopes

Science.gov (United States)

Taylor, Malinda S.; McGraw, J. T.; Zimmer, P. C.

2013-01-01

Anomalous refraction is described as a low frequency, large angular scale motion of the entire image plane with respect to the celestial coordinate system as observed and defined by previous astrometric catalogs. These motions of typically several tenths of an arcsecond with timescales on the order of ten minutes are ubiquitous to drift-scan ground-based astrometric measurements regardless of location or telescopes used and have been attributed to meter scale slowly evolving coherent dynamical structures in the boundary-layer below 60 meters. The localized nature of the effect and general inconsistency of the motions seen by even closely spaced telescopes in individual domes has led to the hypothesis that the dome or other type of telescope housing may be responsible. This hypothesis is tested by observing anomalous refraction using two telescopes housed in a single roll-off roof observatory building with the expected outcome that the two telescopes will see correlated anomalous refraction induced motions.

Ideas for future large single dish radio telescopes

Science.gov (United States)

Kärcher, Hans J.; Baars, Jacob W. M.

2014-07-01

The existing large single dish radio telescopes of the 100m class (Effelsberg, Green Bank) were built in the 1970s and 1990s. With some active optics they work now down to 3 millimeter wavelength where the atmospheric quality of the site is also a limiting factor. Other smaller single dish telescopes (50m LMT Mexico, 30m IRAM Spain) are located higher and reach sub-millimeter quality, and the much smaller 12m antennas of the ALMA array reach at a very high site the Terahertz region. They use advanced technologies as carbon fiber structures and flexible body control. We review natural limits to telescope design and use the examples of a number of telescopes for an overview of the available state-of-the-art in design, engineering and technologies. Without considering the scientific justification we then offer suggestions to realize ultimate performance of huge single dish telescopes (up to 160m). We provide an outlook on design options, technological frontiers and cost estimates.

Revisiting the Effectiveness of Large Optical Telescopes

Directory of Open Access Journals (Sweden)

V. V. Sychev

2015-01-01

Full Text Available To create large-size optical telescopes, various design concepts have been used. Each concept inevitably faced the challenge to optimize technical characteristics and parameters of the telescope. There was always a question: what concept to choose, how to estimate efficiency of such telescopes and by what criteria and how to estimate expediency of this or that project of the large-size telescope. It is, obviously, insufficient to make a resolution-based estimation. An estimate by the angular field size is inappropriate too. Well, it may be also an estimate by the stellar magnitude. All these criteria are related to each other. Improvement of one of these parameters inevitably leads to deterioration of the others. Obviously, the certain generalized criterion considering all parameters and features of the design concept of the large-size telescope is necessary here. As such can serve the criterion of informational content of the telescope.The article offers a complex criterion allowing not only to estimate efficiency of large-size optical telescopes, but also to compare their conceptual and technological level among themselves in terms of obtaining information.The article suggests a new term, i.e. the informational content invariant to characterize informative capacities of the chosen concept and of the realizing technology. It will allow us to avoid unjustified complications of technical solutions, wrong accents in designing and excess material inputs when developing the project.The informational content criterion-based analysis of the existing projects of large-size telescopes has been convincingly shown that, conceptually, there are three best telescopes, namely: GSMT, CELT, and ACT-25. And, in terms of informational content, the АCТ-25 is 10 times more than GSMT and CELT, and the existing Keck-telescope exceeds by 30 times. Hence, it is hard to escape a conclusion that it is more favourable to implement one ACT-25, than to do 10 GSMT or CELT

Simulation of the Simbol-X Telescope

International Nuclear Information System (INIS)

Chauvin, M.; Roques, J. P.

2009-01-01

We have developed a simulation tool for a Wolter I telescope operating in formation flight. The aim is to understand and predict the behavior of the Simbol-X instrument. As the geometry is variable, formation flight introduces new challenges and complex implications. Our code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, along with the relative drifts of the two spacecrafts. It takes into account angle and energy dependent interactions of the photons with the mirrors and applies to any grazing incidence telescope. The resulting images of simulated sources from 0.1 keV to 100 keV allow us to optimize the configuration of the instrument and to assess the performance of the Simbol-X telescope.

Simulation of the Simbol-X Telescope

Science.gov (United States)

Chauvin, M.; Roques, J. P.

2009-05-01

We have developed a simulation tool for a Wolter I telescope operating in formation flight. The aim is to understand and predict the behavior of the Simbol-X instrument. As the geometry is variable, formation flight introduces new challenges and complex implications. Our code, based on Monte Carlo ray tracing, computes the full photon trajectories up to the detector plane, along with the relative drifts of the two spacecrafts. It takes into account angle and energy dependent interactions of the photons with the mirrors and applies to any grazing incidence telescope. The resulting images of simulated sources from 0.1 keV to 100 keV allow us to optimize the configuration of the instrument and to assess the performance of the Simbol-X telescope.

The VTIE telescope resource management system

Science.gov (United States)

Busschots, B.; Keating, J. G.

2005-06-01

The VTIE Telescope Resource Management System (TRMS) provides a frame work for managing a distributed group of internet telescopes as a single "Virtual Observatory". The TRMS provides hooks which allow for it to be connected to any Java Based web portal and for a Java based scheduler to be added to it. The TRMS represents each telescope and observatory in the system with a software agent and then allows the scheduler and web portal to communicate with these distributed resources in a simple transparent way, hence allowing the scheduler and portal designers to concentrate only on what they wish to do with these resources rather than how to communicate with them. This paper outlines the structure and implementation of this frame work.

The NuSTAR Extragalactic Surveys: Overview And Catalog From The Cosmos Field

DEFF Research Database (Denmark)

Civano, F.; Hickox, R. C.; Puccetti, S.

2015-01-01

To provide the census of the sources contributing to the X-ray background peak above 10 keV, Nuclear Spectroscopic Telescope Array (NuSTAR) is performing extragalactic surveys using a three-tier "wedding cake" approach. We present the NuSTAR survey of the COSMOS field, the medium sensitivity...

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

Direct illumination LED calibration for telescope photometry

International Nuclear Information System (INIS)

Barrelet, E.; Juramy, C.

2008-01-01

A calibration method for telescope photometry, based on the direct illumination of a telescope with a calibrated light source regrouping multiple LEDs, is proposed. Its purpose is to calibrate the instrument response. The main emphasis of the proposed method is the traceability of the calibration process and a continuous monitoring of the instrument in order to maintain a 0.2% accuracy over a period of years. Its specificity is to map finely the response of the telescope and its camera as a function of all light ray parameters. This feature is essential to implement a computer model of the instrument representing the variation of the overall light collection efficiency of each pixel for various filter configurations. We report on hardware developments done for SNDICE, the first application of this direct illumination calibration system which will be installed in Canada France Hawaii telescope (CFHT) for its leading supernova experiment (SNLS)

Construction of the Advanced Technology Solar Telescope

Science.gov (United States)

Rimmele, T. R.; Keil, S.; McMullin, J.; Knölker, M.; Kuhn, J. R.; Goode, P. R.; Rosner, R.; Casini, R.; Lin, H.; Tritschler, A.; Wöger, F.; ATST Team

2012-12-01

The 4m Advance Technology Solar Telescope (ATST) will be the most powerful solar telescope and the world's leading ground-based resource for studying solar magnetism that controls the solar wind, flares, coronal mass ejections and variability in the Sun's output. The project has entered its construction phase. Major subsystems have been contracted. As its highest priority science driver ATST shall provide high resolution and high sensitivity observations of the dynamic solar magnetic fields throughout the solar atmosphere, including the corona at infrared wavelengths. With its 4m aperture, ATST will resolve features at 0.″03 at visible wavelengths and obtain 0.″1 resolution at the magnetically highly sensitive near infrared wavelengths. A high order adaptive optics system delivers a corrected beam to the initial set of state-of-the-art, facility class instrumentation located in the Coudé laboratory facility. The initial set of first generation instruments consists of five facility class instruments, including imagers and spectro-polarimeters. The high polarimetric sensitivity and accuracy required for measurements of the illusive solar magnetic fields place strong constraints on the polarization analysis and calibration. Development and construction of a four-meter solar telescope presents many technical challenges, including thermal control of the enclosure, telescope structure and optics and wavefront control. A brief overview of the science goals and observational requirements of the ATST will be given, followed by a summary of the design status of the telescope and its instrumentation, including design status of major subsystems, such as the telescope mount assembly, enclosure, mirror assemblies, and wavefront correction

Hungaria Asteroid Region Telescopic Spectral Survey (HARTSS): Stony Asteroids Abundant in the Background and Family Populations

Science.gov (United States)

Lucas, Michael P.; Emery, Joshua P.; Pinilla-Alonso, Noemi; Lindsay, Sean S.; Lorenzi, Vania

2016-10-01

The Hungaria region represents a "purgatory" for the closest, preserved samples of the material from which the terrestrial planets accreted. The Hungaria region harbors a collisional family of Xe-type asteroids, which are situated among a background of predominantly S-complex asteroids. Deciphering their surface composition may provide constraints on the nature of the primordial building blocks of the terrestrial planets. We hypothesize that planetesimals in the inner part of the primordial asteroid belt experienced partial- to full-melting and differentiation, the Hungaria region should retain any petrologically-evolved material that formed there.We have undertaken an observational campaign entitled the Hungaria Asteroid Region Telescopic Spectral Survey (HARTSS) to record near-infrared (NIR) spectra to characterize taxonomy, surface mineralogy, and potential meteorite analogs. We used NIR instruments at two ground-based facilities (NASA IRTF; TNG). Our data set includes spectra of 82 Hungaria asteroids (61 background; 21 family), 65 were observed during HARTSS. We compare S-complex background asteroids to calibrations developed via laboratory analyses of ordinary chondrites, and to our analyses (EPMA, XRD, VIS+NIR spectra) of 11 primitive achondrite (acapulcoite-lodranite clan) meteorites.We find that stony S-complex asteroids dominate the Hungaria background population (~80%). Background objects exhibit considerable spectral diversity, when quantified by spectral band parameter measurements, translates to a variety of surface compositions. Two main meteorite groups are represented within the Hungaria background: unmelted, nebular L chondrites (and/or L chondrites), and partially-melted primitive achondrites. H-chondrite mineralogies appear to be absent from the Hungaria background. Xe-type Hungaria family members exhibit spectral homogeneity, consistent with the hypothesis that the family was derived from the disruption of a parent body analogous to an enstatite

Far Sidelobes Measurement of the Atacama Cosmology Telescope

Science.gov (United States)

Duenner, Rolando; Gallardo, Patricio; Wollack, Ed; Henriquez, Fernando; Jerez-Hanckes, Carlos

2012-01-01

The Atacama Cosmology Telescope (ACT) is a 6m telescope designed to map the Cosmic Microwave Background (CMB) simultaneously at 145GHz, 220 GHz and 280 GHz. Its off-axis Gregorian design is intended to minimize and control the off-axis sidelobe response, which is critical for scientific purposes. The expected sidelobe level for this kind of design is less than -50 dB and can be challenging to measure. Here we present a measurement of the 145 GHz far sidelobes of ACT done on the near-field of the telescope. We used a 1 mW microwave source placed 13 meters away from the telescope and a chopper wheel to produce a varying signal that could be detected by the camera for different orientations of the telescope. The source feed was designed to produce a wide beam profile. Given that the coupling is expected to be dominated by diffraction over the telescope shielding structure, when combined with a measurements of the main beam far field response, these measurement can be used to validate elements of optical design and constrain the level of spurious coupling at large angles. Our results show that the diffractive coupling beyond the ground screen is consistently below -75 dB, satisfying the design expectations.

[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.

THE ARECIBO METHANOL MASER GALACTIC PLANE SURVEY. III. DISTANCES AND LUMINOSITIES

International Nuclear Information System (INIS)

Pandian, J. D.; Menten, K. M.; Goldsmith, P. F.

2009-01-01

We derive kinematic distances to the 86 6.7 GHz methanol masers discovered in the Arecibo Methanol Maser Galactic Plane Survey. The systemic velocities of the sources were derived from 13 CO (J = 2-1), CS (J = 5-4), and NH 3 observations made with the ARO Submillimeter Telescope, the APEX telescope, and the Effelsberg 100 m telescope, respectively. Kinematic distance ambiguities were resolved using H I self-absorption with H I data from the VLA Galactic Plane Survey. We observe roughly three times as many sources at the far distance compared to the near distance. The vertical distribution of the sources has a scale height of ∼ 30 pc, and is much lower than that of the Galactic thin disk. We use the distances derived in this work to determine the luminosity function of 6.7 GHz maser emission. The luminosity function has a peak at approximately 10 -6 L sun . Assuming that this luminosity function applies, the methanol maser population in the Large Magellanic Cloud and M33 is at least 4 and 14 times smaller, respectively, than in our Galaxy.

The Associate Principal Astronomer for AI Management of Automatic Telescopes

Science.gov (United States)

Henry, Gregory W.

1998-01-01

This research program in scheduling and management of automatic telescopes had the following objectives: 1. To field test the 1993 Automatic Telescope Instruction Set (ATIS93) programming language, which was specifically developed to allow real-time control of an automatic telescope via an artificial intelligence scheduler running on a remote computer. 2. To develop and test the procedures for two-way communication between a telescope controller and remote scheduler via the Internet. 3. To test various concepts in Al scheduling being developed at NASA Ames Research Center on an automatic telescope operated by Tennessee State University at the Fairborn Observatory site in southern Arizona. and 4. To develop a prototype software package, dubbed the Associate Principal Astronomer, for the efficient scheduling and management of automatic telescopes.

An off-the-shelf guider for the Palomar 200-inch telescope: interfacing amateur astronomy software with professional telescopes for an easy life

Science.gov (United States)

Clarke, Fraser; Lynn, James; Thatte, Niranjan; Tecza, Matthias

2014-08-01

We have developed a simple but effective guider for use with the Oxford-SWIFT integral field spectrograph on the Palomar 200-inch telescope. The guider uses mainly off-the-shelf components, including commercial amateur astronomy software to interface with the CCD camera, calculating guiding corrections, and send guide commands to the telescope. The only custom piece of software is an driver to provide an interface between the Palomar telescope control system and the industry standard 'ASCOM' system. Using existing commercial software provided a very cheap guider (guiding, and could easily be adapted to any other professional telescope

Telescope Construction: A Hands-On Approach to Astronomy Education

Science.gov (United States)

Sarrazine, Angela R.; Albin, E.

2009-01-01

We report on a popular semester-long telescope making course offered at Fernbank Science Center in Atlanta, GA. The program is tailored for junior / senior level high school students and incorporates the current educational performance standards for the state of Georgia. This course steps out of the traditional classroom environment and allows students to explore optics and astronomical concepts by constructing their own telescopes. Student telescopes follow the classic six-inch f/8 Newtonian reflector design, which has proven to be a good compromise between portability and aperture. Participants meet for a few hours, twice weekly, to build their telescopes. Over the course of the semester, raw one-inch thick Pyrex mirror blanks are ground, polished, and figured by hand into precision telescope objectives. Along the way, students are introduced to the Ronchi and Foucault methods for testing optics and once figured, completed mirrors are then chemically silvered. A plywood Dobsonian-style base is built and eventually mated with an optical tube made from a standard eight-inch concrete form tube or sonotube. An evening of star testing the optics and observation is planned at the end of the semester to insure the proper operation of each telescope. In summary, we believe that a hands-on approach to the understanding and use of optical telescopes is a great way not only to instill enthusiasm among students for the night sky, but may perhaps inspire the next generation of professional telescope makers.

Hubble Space Telescope, Faint Object Camera

Science.gov (United States)

1981-01-01

This drawing illustrates Hubble Space Telescope's (HST's), Faint Object Camera (FOC). The FOC reflects light down one of two optical pathways. The light enters a detector after passing through filters or through devices that can block out light from bright objects. Light from bright objects is blocked out to enable the FOC to see background images. The detector intensifies the image, then records it much like a television camera. For faint objects, images can be built up over long exposure times. The total image is translated into digital data, transmitted to Earth, and then reconstructed. 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 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, Cornecticut, developed the optical system and guidance sensors.

The big data telescope

International Nuclear Information System (INIS)

Finkel, Elizabeth

2017-01-01

On a flat, red mulga plain in the outback of Western Australia, preparations are under way to build the most audacious telescope astronomers have ever dreamed of - the Square Kilometre Array (SKA). Next-generation telescopes usually aim to double the performance of their predecessors. The Australian arm of SKA will deliver a 168-fold leap on the best technology available today, to show us the universe as never before. It will tune into signals emitted just a million years after the Big Bang, when the universe was a sea of hydrogen gas, slowly percolating with the first galaxies. Their starlight illuminated the fledgling universe in what is referred to as the “cosmic dawn”.

Proxy magnetometry with the Dutch Open Telescope

NARCIS (Netherlands)

Rutten, R.J.; Hammerschlag, R.H.; Sütterlin, P.; Bettonvil, F.C.M.

1999-01-01

Superb movies from the Dutch Open Telescope (DOT) on La Palma have proven the validity of the open concept of this innovative telescope for high-resolution imaging of the solar atmosphere. A five- camera speckle-burst registration system is being installed that should permit consistent and

Robo-AO M Dwarf Multiplicity Survey

Science.gov (United States)

Lamman, Claire; Baranec, Christoph; Berta-Thompson, Zachory K.; Law, Nicholas M.; Ziegler, Carl; Schonhut-Stasik, Jessica

2018-06-01

We analyzed close to 7,000 observations from Robo-AO’s field M dwarf survey taken on the 2.1m Kitt Peak telescope. Results will help determine the total multiplicity fraction and multiplicity functions of M dwarfs, which are crucial steps towards understanding their evolution and formation mechanics. Through its robotic, laser-guided, and automated system, the Robo-AO instrument has yielded the largest adaptive-optics M dwarf survey to date. I developed a graphical user interface to quickly analyze this data. Initial data analysis included assessing data quality, checking the result from Robo-AO’s automatic reduction pipeline, and determining existence as well as the relative position of companions through a visual inspection. This program can be applied to other datasets and was successfully tested by re-analyzing observations from a separate Robo-AO survey. After a conservative initial cut for quality, over 350 companions were found within 4” of a primary star out of 2,746 high quality Robo-AO M dwarf observations, including four triple systems. Further observations were done with the Keck II telescope by using its NIRC2 imager to follow up on ten select targets for the existence and physical association of companions. Future research will yield insights into low-mass stellar formation and provide a database of nearby M dwarf multiples that will potentially assist ongoing and future surveys for planets around these stars, such as the NASA TESS mission.

Finding A Planet Through the Dust

Science.gov (United States)

Kohler, Susanna

2018-05-01

fellow at the Jet Propulsion Laboratory (JPL), a team of scientists now presents preliminary results from a near-infrared microlensing survey conducted with the United Kingdom Infrared Telescope (UKIRT) in Hawaii. Though the full study has not yet been published, the team reports on their first outcome: the detection of a giant planet in the galactic bulge.Giant Planet FoundThe light curve of UKIRT-2017-BLG-001. The inset shows a close-up of the anomaly in the curve, produced by the presence of the planet. [Shvartzvald et al. 2018]UKIRT-2017-BLG-001 is a giant planet detected at an angle of just 0.35 from the dusty, crowded Galactic center. It suffers from a high degree of extinction, implying that this planet could only have been detected via a near-infrared survey. The mass ratio of UKIRT-2017-BLG-001 to its host star is about 1.5 times that of Jupiter to the Sun, and its host star appears to be about 80% the mass of the Sun.The starplanet pair is roughly 20,500 light-years from us, which likely places it in the galactic bulge. Intriguingly, evidence suggests that the source star the star that the foreground starplanet lensed lies in the far galactic disk. If this is true, this would be the first source star of a microlensing event to be identified as belonging to the far disk.Artists impression of the WFIRST mission. [NASA]Looking AheadWhats next for microlensing exoplanet studies? The goal of the UKIRT near-infrared microlensing survey isnt just to discover planets its to characterize the exoplanet occurrence rates in different parts of the galaxy to inform future surveys.In particular, the UKIRT survey explored potential fields for the upcoming Wide Field Infrared Survey Telescope (WFIRST) mission, slated to launch in the mid-2020s. This powerful space telescope stands to vastly expand the reach of infrared microlensing detection, broadly surveying our galaxy for planets hiding in the dust.CitationY. Shvartzvald et al 2018 ApJL 857 L8. doi:10.3847/2041-8213/aab71b

Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628

Science.gov (United States)

Adamo, A.; Ryon, J. E.; Messa, M.; Kim, H.; Grasha, K.; Cook, D. O.; Calzetti, D.; Lee, J. C.; Whitmore, B. C.; Elmegreen, B. G.; Ubeda, L.; Smith, L. J.; Bright, S. N.; Runnholm, A.; Andrews, J. E.; Fumagalli, M.; Gouliermis, D. A.; Kahre, L.; Nair, P.; Thilker, D.; Walterbos, R.; Wofford, A.; Aloisi, A.; Ashworth, G.; Brown, T. M.; Chandar, R.; Christian, C.; Cignoni, M.; Clayton, G. C.; Dale, D. A.; de Mink, S. E.; Dobbs, C.; Elmegreen, D. M.; Evans, A. S.; Gallagher, J. S., III; Grebel, E. K.; Herrero, A.; Hunter, D. A.; Johnson, K. E.; Kennicutt, R. C.; Krumholz, M. R.; Lennon, D.; Levay, K.; Martin, C.; Nota, A.; Östlin, G.; Pellerin, A.; Prieto, J.; Regan, M. W.; Sabbi, E.; Sacchi, E.; Schaerer, D.; Schiminovich, D.; Shabani, F.; Tosi, M.; Van Dyk, S. D.; Zackrisson, E.

2017-06-01

We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes ˜ -2 and a truncation of a few times 105 {M}⊙ . After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find mass-independent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (≤104 {M}⊙ ) clusters, suggesting that a mass-dependent component is necessary to fully describe the YSC disruption process in NGC 628. Based on observations obtained with the NASA/ESA Hubble Space Telescope, at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

Fermi Large Area Telescope Operations: Progress Over 4 Years

Energy Technology Data Exchange (ETDEWEB)

Cameron, Robert A.; /SLAC

2012-06-28

The Fermi Gamma-ray Space Telescope was launched into orbit in June 2008, and is conducting a multi-year gamma-ray all-sky survey, using the main instrument on Fermi, the Large Area Telescope (LAT). Fermi began its science mission in August 2008, and has now been operating for almost 4 years. The SLAC National Accelerator Laboratory hosts the LAT Instrument Science Operations Center (ISOC), which supports the operation of the LAT in conjunction with the Mission Operations Center (MOC) and the Fermi Science Support Center (FSSC), both at NASA's Goddard Space Flight Center. The LAT has a continuous output data rate of about 1.5 Mbits per second, and data from the LAT are stored on Fermi and transmitted to the ground through TDRS and the MOC to the ISOC about 10 times per day. Several hundred computers at SLAC are used to process LAT data to perform event reconstruction, and gamma-ray photon data are subsequently delivered to the FSSC for public release with a few hours of being detected by the LAT. We summarize the current status of the LAT, and the evolution of the data processing and monitoring performed by the ISOC during the first 4 years of the Fermi mission, together with future plans for further changes to detected event data processing and instrument operations and monitoring.

Possible GRB Observation with the MAGIC Telescope

Science.gov (United States)

Bastieri, D.; Bigongiari, C.; Mariotti, M.; Peruzzo, L.; Saggion, A.

2001-08-01

The MAGIC Telescope, with its reflecting parabolic dish of 17 m of diameter and its careful design of a robust, lightweight, alto-azimuthal mount, is an ideal detector for GRB phenomena. The telescope is an air Cherenkov telescope that, even in the first phase, equipped with standard PMTs, can reach an energy threshold below 30 GeV. The threshold is going to drop well below 10 GeV in the envisaged second phase, when chamber PMTs will be substituted by high quantum efficiency APDs. The telescope can promptly respond to GRB alerts coming, for instance, from GCN, and can reposition itself in less than 30 seconds, 20 seconds being the time to turn half a round for the azimuth bearing. In this report, the effective area of the detector as a function of energy and zenith angle is taken into account, in order to evaluate the expected yearly occurrence and the response to different kinds of GRBs.

Space telescopes capturing the rays of the electromagnetic spectrum

CERN Document Server

English, Neil

2017-01-01

Space telescopes are among humankind’s greatest scientific achievements of the last fifty years. This book describes the instruments themselves and what they were designed to discover about the Solar System and distant stars. Exactly how these telescopes were built and launched and the data they provided is explored. Only certain kinds of radiation can penetrate our planet's atmosphere, which limits what we can observe. But with space telescopes all this changed. We now have the means to "see" beyond Earth using ultraviolet, microwave, and infrared rays, X-rays and gamma rays. In this book we meet the pioneers and the telescopes that were built around their ideas. This book looks at space telescopes not simply chronologically but also in order of the electromagnetic spectrum, making it possible to understand better why they were made.