Science.gov

Sample records for 8gr8 cygnus survey

  1. The VERITAS Survey of the Cygnus Region of the Galaxy

    NASA Astrophysics Data System (ADS)

    Popkow, Alexis; Aune, Taylor; Ong, Rene A.; Ward, John E

    2014-08-01

    VERITAS (Very Energetic Radiation Imaging Telescope Array System) is an array of four 12 m diameter Imaging Atmospheric Cherenkov Telescopes (IACTs) located at Mt Hopkins, AZ. From 2007 to 2009 VERITAS undertook an extensive survey of the Cygnus region from 67 to 82 degrees Galactic longitude and from -1 to 4 degrees in Galactic latitude. This is a region with many promising Very High Energy (VHE) gamma-ray candidates such as supernova remnants, pulsar wind nebulae, high mass X-ray binaries and massive star clusters including previously detected VHE gamma-ray sources and dozens of GeV gamma-ray sources (detected by the Fermi-LAT). Along with the initial 140 hours of observations, there are over 150 hrs (a total of 294 hours after cuts for bad weather) of follow-up pointed VERITAS observations in the region that we are analyzing with updated analysis techniques. Here we present the current status of this analysis, and of an analysis of over five years of Fermi-LAT data in the region. Using a cross correlation of these results we can motivate continued observations in this active region of the Galaxy, and will incorporate multi-wavelength perspectives into a future results paper.

  2. The JCMT 12CO(3-2) survey of the Cygnus X region. I. A pathfinder

    NASA Astrophysics Data System (ADS)

    Gottschalk, M.; Kothes, R.; Matthews, H. E.; Landecker, T. L.; Dent, W. R. F.

    2012-05-01

    Context. Cygnus X is one of the most complex areas in the sky, rich in massive stars; Cyg OB2 (2600 stars, 120 O stars) and other OB associations lie within its boundaries. This complicates interpretation, but also creates the opportunity to investigate accretion into molecular clouds and many subsequent stages of star formation, all within one small field of view. Understanding large complexes like Cygnus X is the key to understanding the dominant role that massive star complexes play in galaxies across the Universe. Aims: The main goal of this study is to establish feasibility of a high-resolution CO survey of the entire Cygnus X region by observing part of it as a pathfinder, and to evaluate the survey as a tool for investigating the star-formation process. We can investigate the mass accretion history of outflows, study interaction between star-forming regions and their cold environment, and examine triggered star formation around massive stars. Methods: A 2° × 4° area of the Cygnus X region has been mapped in the 12CO(3-2) line at an angular resolution of 15'' and a velocity resolution of ~0.4 km s-1 using HARP-B and ACSIS on the James Clerk Maxwell Telescope. The star formation process is heavily connected to the life-cycle of the molecular material in the interstellar medium. The high critical density of the 12CO(3-2) transition reveals clouds in key stages of molecule formation, and shows processes that turn a molecular cloud into a star. Results: We observed ~15% of Cygnus X, and demonstrated that a full survey would be feasible and rewarding. We detected three distinct layers of 12CO(3-2) emission, related to the Cygnus Rift (500-800 pc), to W75N (1-1.8 kpc), and to DR 21 (1.5-2.5 kpc). Within the Cygnus Rift, H i self-absorption features are tightly correlated with faint diffuse CO emission, while HISA features in the DR 21 layer are mostly unrelated to any CO emission. 47 molecular outflows were detected in the pathfinder, 27 of them previously

  3. Detection ratios on winter surveys of Rocky Mountain Trumpeter Swans Cygnus buccinator

    USGS Publications Warehouse

    Bart, J.; Mitchell, C.D.; Fisher, M.N.; Dubovsky, J.A.

    2007-01-01

    We estimated the detection ratio for Rocky Mountain Trumpeter Swans Cygnus buccinator that were counted during aerial surveys made in winter. The standard survey involved counting white or grey birds on snow and ice and thus might be expected to have had low detection ratios. On the other hand, observers were permitted to circle areas where the birds were concentrated multiple times to obtain accurate counts. Actual numbers present were estimated by conducting additional intensive aerial counts either immediately before or immediately after the standard count. Surveyors continued the intensive surveys at each area until consecutive counts were identical. The surveys were made at 10 locations in 2006 and at 19 locations in 2007. A total of 2,452 swans were counted on the intensive surveys. Detection ratios did not vary detectably with year, observer, which survey was conducted first, age of the swans, or the number of swans present. The overall detection ratio was 0.93 (90% confidence interval 0.82-1.04), indicating that the counts were quite accurate. Results are used to depict changes in population size for Rocky Mountain Trumpeter Swans from 1974-2007. ?? Wildfowl & Wetlands Trust.

  4. AN R- AND I-BAND PHOTOMETRIC VARIABILITY SURVEY OF THE CYGNUS OB2 ASSOCIATION

    SciTech Connect

    Henderson, C. B.; Stanek, K. Z.; Pejcha, O.; Prieto, J. L.

    2011-06-01

    We present a catalog of photometrically variable stars discovered within two 21.'3 x 21.'3 fields centered on the Cygnus OB2 association (Cyg OB2). There have hitherto been no deep optical variability studies of Cyg OB2, despite it being replete with early-type massive stars, likely due to the high and variable extinction (up to A{sub V} {approx} 20) that permeates much of the region. Here, we provide results of the first variability study with this combination of spatial coverage ({approx}0.5 deg) and photometric depth (R {approx} 21 mag). We find 121 stars to be variable in both R and I bands, 115 of them newly discovered. Of the 121 variables, we identify 27 eclipsing binaries and eclipsing-binary candidates, 52 pulsating variables, and 20 potential Herbig Ae/Be stars. Confirming both the status and the cluster membership of the Herbig Ae/Be stars would address the uncertainty regarding the age and star formation history of Cyg OB2. We match our catalog to known variables and binaries in the region, Two Micron All Sky Survey near-IR data, and Chandra X-ray observations to find counterparts to new variables in other wavelengths.

  5. Cygnus History

    SciTech Connect

    David J. Henderson, Raymond E. Gignac, Douglas E. Good, Mark D. Hansen, Charles V. Mitton; Daniel S. Nelson, Eugene C. Ormond; Steve R. Cordova, Isidro Molina; John R. Smith, Evan A. Rose

    2009-07-02

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources: Cygnus 1 and Cygnus 2. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site. The sources were developed to produce high-resolution images for dynamic plutonium experiments. This work will recount and discuss salient maintenance and operational issues encountered during the history of Cygnus. A brief description of Cygnus systems and rational for design selections will set the stage for this historical narrative. It is intended to highlight the team-derived solutions for technical problems encountered during extended periods of maintenance and operation. While many of the issues are typical to pulsed power systems, some of the solutions are unique. It is hoped that other source teams will benefit from this presentation, as well as other necessary disciplines (e.g., source users, system architects, facility designers and managers, funding managers, and team leaders).

  6. A Multi-Frequency VLBA Survey of Interstellar Scattering in the Cygnus X Region

    NASA Astrophysics Data System (ADS)

    Mutel, R. L.; Molnar, L. A.; Spangler, S. R.

    1998-05-01

    We describe the results of a multi-frequency VLBA study of the scatter-broadened images of fifteen compact extragalactic sources. The sources are located along lines of sight which intercept the Cygnus X superbubble. We have used the phase structure function to determine the spatial spectrum of turbulence with high SNR on scales from 100 to 6,000 km. We will discuss evidence for detection of an inner scale length along some lines of sight as well as excess visibility amplitude for projected baseline lengths much greater than the diffractive scale. We also find that most scattered-broadened images are significantly elliptical with orientations which may be related to the large-scale magnetic field orientation in the Cygnus superbubble.

  7. Toward Complete Statistics of Massive Binary Stars: Penultimate Results from the Cygnus OB2 Radial Velocity Survey

    NASA Astrophysics Data System (ADS)

    Kobulnicky, Henry A.; Kiminki, Daniel C.; Lundquist, Michael J.; Burke, Jamison; Chapman, James; Keller, Erica; Lester, Kathryn; Rolen, Emily K.; Topel, Eric; Bhattacharjee, Anirban; Smullen, Rachel A.; Vargas Álvarez, Carlos A.; Runnoe, Jessie C.; Dale, Daniel A.; Brotherton, Michael M.

    2014-08-01

    We analyze orbital solutions for 48 massive multiple-star systems in the Cygnus OB2 association, 23 of which are newly presented here, to find that the observed distribution of orbital periods is approximately uniform in log P for P < 45 days, but it is not scale-free. Inflections in the cumulative distribution near 6 days, 14 days, and 45 days suggest key physical scales of sime0.2, sime0.4, and sime1 A.U. where yet-to-be-identified phenomena create distinct features. No single power law provides a statistically compelling prescription, but if features are ignored, a power law with exponent β ~= -0.22 provides a crude approximation over P = 1.4-2000 days, as does a piece-wise linear function with a break near 45 days. The cumulative period distribution flattens at P > 45 days, even after correction for completeness, indicating either a lower binary fraction or a shift toward low-mass companions. A high degree of similarity (91% likelihood) between the Cyg OB2 period distribution and that of other surveys suggests that the binary properties at P <~ 25 days are determined by local physics of disk/clump fragmentation and are relatively insensitive to environmental and evolutionary factors. Fully 30% of the unbiased parent sample is a binary with period P < 45 days. Completeness corrections imply a binary fraction near 55% for P < 5000 days. The observed distribution of mass ratios 0.2 < q < 1 is consistent with uniform, while the observed distribution of eccentricities 0.1 < e < 0.6 is consistent with uniform plus an excess of e ~= 0 systems. We identify six stars, all supergiants, that exhibit aperiodic velocity variations of ~30 km s-1 attributed to atmospheric fluctuations.

  8. A WIDE-FIELD NARROWBAND OPTICAL SURVEY OF THE BRAID NEBULA STAR FORMATION REGION IN CYGNUS OB7

    SciTech Connect

    Magakian, Tigran Yu.; Nikogossian, Elena H.; Movsessian, Tigran; Aspin, Colin; Pyo, Tae-Soo; Khanzadyan, Tigran; Smith, Michael D.; Mitchison, Sharon; Davis, Chris J.; Beck, Tracy L.; Moriarty-Schieven, Gerald H. E-mail: elena@bao.sci.am E-mail: pyo@subaru.naoj.org E-mail: smm23@kent.ac.uk E-mail: c.davis@jach.hawaii.edu E-mail: gerald.schieven@nrc-cnrc.gc.ca

    2010-03-15

    We study the population of Herbig-Haro (HH) flows and jets in an area of Cygnus OB7 designated the Braid Nebula star formation region. This complex forms part of the L 1003 dark cloud, and hosts two FU Orionis (FUor)-like objects as well as several other active young stars. To trace outflow activity and to relate both known and newly discovered flows to young star hosts we intercompare new, deep, narrowband H{alpha} and [S II] optical images taken on the Subaru 8 m Telescope on Mauna Kea, Hawaii. Our images show that there is considerable outflow and jet activity in this region suggesting the presence of an extensive young star population. We confirm that both of the FUor-like objects drive extensive HH flows and document further members of the flows in both objects. The L 1003 star formation complex is a highly kinematically active region with young stars in several different stages of evolution. We trace collimated outflows from numerous young stars although the origin of some HH objects remains elusive.

  9. A high angular resolution survey of massive stars in Cygnus OB2: Results from the Hubble space telescope fine guidance sensors

    SciTech Connect

    Caballero-Nieves, S. M.; Gies, D. R.; Jao, W.-C. E-mail: gies@chara.gsu.edu; and others

    2014-02-01

    We present results of a high angular resolution survey of massive OB stars in the Cygnus OB2 association that we conducted with the fine guidance sensor 1R (FGS1r) on the Hubble Space Telescope. FGS1r is able to resolve binary systems with a magnitude difference ΔV < 4 down to separations as small as 0.''01. The sample includes 58 of the brighter members of Cyg OB2, one of the closest examples of an environment containing a large number of very young and massive stars. We resolved binary companions for 12 targets and confirmed the triple nature of one other target, and we offer evidence of marginally resolved companions for two additional stars. We confirm the binary nature of 11 of these systems from complementary adaptive optics imaging observations. The overall binary frequency in our study is 22% to 26% corresponding to orbital periods ranging from 20 to 20,000 yr. When combined with the known short-period spectroscopic binaries, the results support the hypothesis that the binary fraction among massive stars is >60%. One of the new discoveries is a companion to the hypergiant star MT 304 = Cyg OB2-12, and future measurements of orbital motion should provide mass estimates for this very luminous star.

  10. Cygnus Water Switch Jitter

    SciTech Connect

    Charles V. Mitton, George D. Corrow, Mark D. Hansen, David J. Henderson, et al.

    2008-03-01

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources - Cygnus 1 and Cygnus 2. Each source has the following x-ray output: 1-mm diameter spot size, 4 rad at 1 m, 50-ns Full Width Half Max. The diode pulse has the following electrical specifications: 2.25 MV, 60 kA, 60 ns. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site (NTS). The sources were developed to produce high-resolution images on subcritical tests which are performed at NTS. Subcritical tests are single-shot, high-value events. For this application, it is desirable to maintain a high level of reproducibility in source output. The major components of the Cygnus machines are: Marx generator, water-filled pulse–forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. A primary source of fluctuation in Cygnus shot-to-shot performance is jitter in breakdown of the main PFL switch, which is a “self-break” switch. The PFL switch breakdown time determines the peak PFL charging voltage, which ultimately affects the diode pulse. Therefore, PFL switch jitter contributes to shot-to-shot variation in source endpoint energy and dose. In this paper we will present PFL switch jitter analysis for both Cygnus machines and give the correlation with diode performance. For this analysis the PFL switch on each machine was maintained at a single gap setting which has been used for the majority of shots at NTS. In addition to this analysis, PFL switch performance for different switch gap settings taken recently will be examined. Lastly, implications of source jitter for radiographic diagnosis of subcritical shots will be discussed.

  11. THE BALLOON-BORNE LARGE APERTURE SUBMILLIMETER TELESCOPE (BLAST) 2005: A 10 deg{sup 2} SURVEY OF STAR FORMATION IN CYGNUS X

    SciTech Connect

    Roy, Arabindo; Netterfield, Calvin B.; Ade, Peter A. R.; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Philip; Bock, James J.; Chapin, Edward L.; Gibb, Andrew G.; Halpern, Mark; Marsden, Gaelen; Devlin, Mark J.; Dicker, Simon R.; Klein, Jeff; France, Kevin; Gundersen, Joshua O.; Hughes, David H.; Martin, Peter G.; Morales Ortiz, Jorge L.; Noriega-Crespo, Alberto

    2011-02-01

    We present Cygnus X in a new multi-wavelength perspective based on an unbiased BLAST survey at 250, 350, and 500 {mu}m, combined with rich data sets for this well-studied region. Our primary goal is to investigate the early stages of high-mass star formation. We have detected 184 compact sources in various stages of evolution across all three BLAST bands. From their well-constrained spectral energy distributions, we obtain the physical properties mass, surface density, bolometric luminosity, and dust temperature. Some of the bright sources reaching 40 K contain well-known compact H II regions. We relate these to other sources at earlier stages of evolution via the energetics as deduced from their position in the luminosity-mass (L-M) diagram. The BLAST spectral coverage, near the peak of the spectral energy distribution of the dust, reveals fainter sources too cool ({approx}10 K) to be seen by earlier shorter-wavelength surveys like IRAS. We detect thermal emission from infrared dark clouds and investigate the phenomenon of cold 'starless cores' more generally. Spitzer images of these cold sources often show stellar nurseries, but these potential sites for massive star formation are 'starless' in the sense that to date there is no massive protostar in a vigorous accretion phase. We discuss evolution in the context of the L-M diagram. Theory raises some interesting possibilities: some cold massive compact sources might never form a cluster containing massive stars, and clusters with massive stars might not have an identifiable compact cold massive precursor.

  12. The Cygnus region of the galaxy: A VERITAS perspective

    NASA Astrophysics Data System (ADS)

    Weinstein, A.

    2015-12-01

    The Cygnus-X star-forming region ("Cygnus") is the richest star-forming region within 2 kpc of Earth and is home to a wealth of potential cosmic ray accelerators, including supernova remnants, massive star clusters, and pulsar wind nebulae. Over the past five years, discoveries by several gamma-ray observatories sensitive in different energy bands, including the identification by Fermi-LAT of a potential cocoon of freshly accelerated cosmic rays, have pinpointed this region as a unique laboratory for studying the early phases of the cosmic ray life cycle. From 2007 to 2009 VERITAS, a very high energy (VHE; E > 100 GeV) observatory in southern Arizona, undertook an extensive survey of the Cygnus region from 67 to 82 degrees Galactic longitude and from -1 to 4 degrees in Galactic latitude. In the years since, VERITAS has continued to accumulate data at specific locations within the survey region. We will review the discoveries and insights that this rich dataset has already provided. We will also consider the key role that we expect these data to play in interpreting the complex multiwavelength picture we have of the Cygnus region, particularly in the vicinity of the Cygnus cocoon. As part of this discussion we will summarize ongoing studies of VERITAS data in the Cygnus region, including the development of new data analysis techniques that dramatically increase VERITAS' sensitivity to sources on scales larger than a square degree.

  13. Cygnus Trigger System

    SciTech Connect

    G. Corrow, M. Hansen, D. Henderson, C. Mitton

    2008-02-01

    The Cygnus Dual Beam Radiographic Facility consists of two radiographic sources (Cygnus 1, Cygnus 2) each with a dose rating of 4 rads at 1 m, and a 1-mm diameter spot size. The electrical specifications are: 2.25 MV, 60 kA, 60 ns. This facility is located in an underground environment at the Nevada Test Site (NTS). These sources were developed as a primary diagnostic for subcritical tests, which are single-shot, high-value events. In such an application there is an emphasis on reliability and reproducibility. A robust, low-jitter trigger system is a key element for meeting these goals. The trigger system was developed with both commercial and project-specific equipment. In addition to the traditional functions of a trigger system there are novel features added to protect the investment of a high-value shot. Details of the trigger system, including elements designed specifically for a subcritical test application, will be presented. The individual electronic components have their nominal throughput, and when assembled have a system throughput with a measured range of jitter. The shot-to-shot jitter will be assessed both individually and in combination. Trigger reliability and reproducibility results will be presented for a substantial number of shots executed at the NTS.

  14. Cygnus Diverter Switch Analysis

    SciTech Connect

    G. Corrow, M. Hansen, D. Henderson, C. Mitton et al.

    2008-02-01

    The Cygnus Dual Beam Radiographic Facility consists of two 2.25-MV, 60-kA, 50-ns x-ray sources fielded in an underground laboratory at the Nevada Test Site. The tests performed in this laboratory involve study of the dynamic properties of plutonium and are called subcritical experiments. From end-to-end, the Cygnus machines utilize the following components: Marx generator, water-filled pulse-forming line (PFL), waterfilled coaxial transmission line (WTL), 3-cell inductive voltage adder (IVA), and rod-pinch diode. The upstream WTL interface to the PFL is via a radial insulator with coaxial geometry. The downstream WTL terminates in a manifold where the center conductor splits into three lines which individually connect to each of the IVA cell inputs. There is an impedance mismatch at this juncture. It is a concern that a reflected pulse due to anomalous behavior in the IVA or diode might initiate breakdown upon arrival at the upstream PFL/WTL insulator. Therefore near the beginning of the WTL a radial diverter switch is installed to protect the insulator from over voltage and breakdown. The diverter has adjustable gap spacing, and an in-line aqueous-solution (sodium thiosulfate) resistor array for energy dissipation. There are capacitive voltage probes at both ends of the WTL and on the diverter switch. These voltage signals will be analyzed to determine diverter performance. Using this analysis the usefulness of the diverter switch will be evaluated.

  15. Tour the Cygnus X Star Factory

    NASA Video Gallery

    This video opens with wide optical and infrared images of the constellation Cygnus, then zooms into the Cygnus X region using radio, infrared and gamma-ray images. Fermi LAT shows that gamma rays f...

  16. Cygnus X-3 Little Friend's Counterpart, the Distance to Cygnus X-3 and Jets (Oh My!)

    NASA Astrophysics Data System (ADS)

    McCollough, Michael L.; Dunham, Michael M.; Corrales, Lia

    2016-04-01

    Chandra observations have revealed a feature within 16" of Cygnus X-3 which varied in phase with Cygnus X-3. This feature was shown to be a Bok globule which is along the line of sight to Cygnus X-3. We report onobservations made with Submillimeter Array (SMA) to search for molecular emission from this globule, also known as Cygnus X-3's "little friend." We have found a counterpart in both 12CO and 13CO emission. From the velocity shift of the molecular lines we are able determine a kinematic distance to the little friend and in turn a distance to Cygnus X-3. The uncertainties in this distance estimate to Cygnus X-3 are less than 10%. An additional unexpected discovery was that Cygnus X-3 is not the only source to have jets!

  17. The Cygnus Loop: An Older Supernova Remnant.

    ERIC Educational Resources Information Center

    Straka, William

    1987-01-01

    Describes the Cygnus Loop, one of brightest and most easily studied of the older "remnant nebulae" of supernova outbursts. Discusses some of the historical events surrounding the discovery and measurement of the Cygnus Loop and makes some projections on its future. (TW)

  18. Cygnus Loop: A double bubble?

    NASA Astrophysics Data System (ADS)

    West, J.; Safi-Harb, S.; Reichardt, I.; Stil, J.; Kothes, R.; Jaffe, T.; Galfacts Team

    2016-06-01

    The Cygnus Loop is a well-studied supernova remnant (SNR) that has been observed across the electromagnetic spectrum. Although widely believed to be an SNR shell with a blow-out region in the south, we consider the possibility that this object is two SNRs projected along the same line-of-sight by using multi-wavelength images and modelling. Our results show that a model of two objects including some overlap region/interaction between the two objects has the best match to the observed data.

  19. Anomalous Proper-Motions in the Cygnus Super Bubble Region

    NASA Astrophysics Data System (ADS)

    Comeron, F.; Torra, J.; Jordi, C.; Gomez, A. E.

    1993-10-01

    In an analysis of proper motions of O and B stars contained in the Input Catalogue for Hipparcos, we have found a clear deviation from the expected pattern of systematic motions which can be readily identified with the associations Cygnus OB1 and Cygnus OB9, located near the edge of the Cygnus Superbubble. The anomalous motions are directed outwards from the center of the Superbubble, which is coincident with the association Cygnus OB2. This seems to support the hypothesis of a strong stellar and supernova activity in Cygnus OB2 giving rise to the Superbubble and, by means of gravitational instabilities in its boundaries, to Cygnus CB1 and Cygnus OB9. New uvbyβ aperture photometry of selected O and B stars in the area of Cygnus OB1 and Cygnus OB9 is also presented and analyzed in this paper.

  20. Search for old neutron stars in molecular clouds: Cygnus rift and Cygnus OB7.

    NASA Astrophysics Data System (ADS)

    Belloni, T.; Zampieri, L.; Campana, S.

    1997-03-01

    We present the results of a systematic search for old isolated neutron stars (ONSs) in the direction of two giant molecular clouds in Cygnus (Rift and OB7). From theoretical calculations, we expect the detection of a large number of ONSs with the PSPC on board ROSAT. By analyzing the PSPC pointings in the direction of the clouds, we find four sources characterized by count rates (~10^-3^ct/s) and spectral properties consistent with the hypothesis that the X-ray radiation is produced by ONSs and also characterized by the absence of any measurable optical counterpart within their error circle in the digitized red plates of the Palomar All Sky Survey. The importance of follow-up deep observations in the direction of these ONS candidates is discussed. The observational and theoretical approach presented here could be fruitfully applied also to the systematic search for ONSs in other regions of the Galaxy.

  1. Recent results from the CYGNUS experiment and plans for the MILAGRO experiment

    SciTech Connect

    Williams, D.A. )

    1992-02-05

    Recent results from the CYGNUS cosmic-ray experiment are presented, including a survey of the northern sky for continuous point sources and a search for emission lasting several hours (one day of observation) from many known x-ray and [gamma]-ray sources. The performance of five water-Cerenkov detectors recently added to the CYGNUS array is summarized. A proposed water-Cerenkov detector called MILAGRO for the detection of cosmic-ray air showers over a broad energy range, 1--1000 TeV, is described.

  2. Cygnus Loop Supernova Blast Wave

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This is an image of a small portion of the Cygnus Loop supernova remnant, which marks the edge of a bubble-like, expanding blast wave from a colossal stellar explosion, occurring about 15,000 years ago. The HST image shows the structure behind the shock waves, allowing astronomers for the first time to directly compare the actual structure of the shock with theoretical model calculations. Besides supernova remnants, these shock models are important in understanding a wide range of astrophysical phenomena, from winds in newly-formed stars to cataclysmic stellar outbursts. The supernova blast is slamming into tenuous clouds of insterstellar gas. This collision heats and compresses the gas, causing it to glow. The shock thus acts as a searchlight revealing the structure of the interstellar medium. The detailed HST image shows the blast wave overrunning dense clumps of gas, which despite HST's high resolution, cannot be resolved. This means that the clumps of gas must be small enough to fit inside our solar system, making them relatively small structures by interstellar standards. A bluish ribbon of light stretching left to right across the picture might be a knot of gas ejected by the supernova; this interstellar 'bullet' traveling over three million miles per hour (5 million kilometres) is just catching up with the shock front, which has slowed down by ploughing into interstellar material. The Cygnus Loop appears as a faint ring of glowing gases about three degrees across (six times the diameter of the full Moon), located in the northern constellation, Cygnus the Swan. The supernova remnant is within the plane of our Milky Way galaxy and is 2,600 light-years away. The photo is a combination of separate images taken in three colors, oxygen atoms (blue) emit light at temperatures of 30,000 to 60,000 degrees Celsius (50,000 to 100,000 degrees Farenheit). Hydrogen atoms (green) arise throughout the region of shocked gas. Sulfur atoms (red) form when the gas cools to

  3. Search for UHE emission from Cygnus X-3

    SciTech Connect

    Stark, M.J.; The CYGNUS Collaboration

    1993-05-01

    Data from the CYGNUS experiment has been searched for evidence of ultra high energy (UHE) emission from Cygnus X-3. An upper limit to continuous flux from the source is given. In addition, we find no evidence for episodic emission from Cygnus X-3 on any time scale from 3.3 minutes to 4 years. The results of searches for periodic emission from Cygnus X-3 will be presented at the conference.

  4. Search for UHE emission from Cygnus X-3

    SciTech Connect

    Stark, M.J.

    1993-01-01

    Data from the CYGNUS experiment has been searched for evidence of ultra high energy (UHE) emission from Cygnus X-3. An upper limit to continuous flux from the source is given. In addition, we find no evidence for episodic emission from Cygnus X-3 on any time scale from 3.3 minutes to 4 years. The results of searches for periodic emission from Cygnus X-3 will be presented at the conference.

  5. Cygnus

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (the Swan; abbrev. Cyg, gen. Cygni; area 804 sq. deg.) A northern constellation which lies between Cepheus and Vulpecula, and culminates at midnight in late July. Its origin is uncertain, though it was known to the ancient Greeks, who identified it with one of the forms assumed by Zeus during his amorous pursuits, or with other mythological swans. Its brightest stars were cataloged by Ptolemy (c....

  6. A SPITZER VIEW OF STAR FORMATION IN THE CYGNUS X NORTH COMPLEX

    SciTech Connect

    Beerer, I. M.; Koenig, X. P.; Hora, J. L.; Keto, E.; Smith, H. A.; Fazio, G. G.; Gutermuth, R. A.; Bontemps, S.; Schneider, N.; Megeath, S. T.; Motte, F.; Simon, R.; Allen, L. E.; Kraemer, K. E.; Price, S.; Mizuno, D.; Adams, J. D.; Hernandez, J.; Lucas, P. W.

    2010-09-01

    We present new images and photometry of the massive star-forming complex Cygnus X obtained with the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS) on board the Spitzer Space Telescope. A combination of IRAC, MIPS, UKIRT Deep Infrared Sky Survey, and Two Micron All Sky Survey data are used to identify and classify young stellar objects (YSOs). Of the 8231 sources detected exhibiting infrared excess in Cygnus X North, 670 are classified as class I and 7249 are classified as class II. Using spectra from the FAST Spectrograph at the Fred L. Whipple Observatory and Hectospec on the MMT, we spectrally typed 536 sources in the Cygnus X complex to identify the massive stars. We find that YSOs tend to be grouped in the neighborhoods of massive B stars (spectral types B0 to B9). We present a minimal spanning tree analysis of clusters in two regions in Cygnus X North. The fraction of infrared excess sources that belong to clusters with {>=}10 members is found to be 50%-70%. Most class II objects lie in dense clusters within blown out H II regions, while class I sources tend to reside in more filamentary structures along the bright-rimmed clouds, indicating possible triggered star formation.

  7. Contributions from the CYGNUS/Milagro Collaboration

    SciTech Connect

    Allen, G.E.; Chang, C.Y.; Chen, M.L.

    1995-09-01

    This document consists of eleven reports contributed to the XXIV International Cosmic Ray Conference (Rome, Italy, August 28--September 8, 1995) from the CYGNUS/Milagro Collaboration: ``Search for Ultra-High-Energy Radiation from Gamma-Ray Bursts``, ``Gamma-Ray Bursts: Detection and Distance Estimates with Milagro``, ``Searching for Gamma-Ray Bursts with Water-Cerenkov-Detector Single-Particle Rates``, ``The Milagro Detector``, ``The Milagro Data Acquisition System``, ``Source Searches Using the CYGNUS Water-Cerenkov Array``, ``Search for UHE Emission from Supernova Remnants``, ``Solar Physics with the Milagro Telescope``, ``An Experiment to Detect Correlations Between Cerenkov and Muon Lateral Distributions in EAS``, ``A Study of Large-Zenith-Angle Air Showers with the CYGNUS Experiment``, and ``Mass Resolution of Ground Based Air Shower Experiments in the 10 to 10000 TeV range.``

  8. The dependence of protostellar luminosity on environment in the Cygnus-X star-forming complex

    SciTech Connect

    Kryukova, E.; Megeath, S. T.; Hora, J. L.; Smith, Howard A.; Gutermuth, R. A.; Bontemps, S.; Schneider, N.; Kraemer, K.; Hennemann, M.; Motte, F.

    2014-07-01

    The Cygnus-X star-forming complex is one of the most active regions of low- and high-mass star formation within 2 kpc of the Sun. Using mid-infrared photometry from the IRAC and MIPS Spitzer Cygnus-X Legacy Survey, we have identified over 1800 protostar candidates. We compare the protostellar luminosity functions of two regions within Cygnus-X: CygX-South and CygX-North. These two clouds show distinctly different morphologies suggestive of dissimilar star-forming environments. We find the luminosity functions of these two regions are statistically different. Furthermore, we compare the luminosity functions of protostars found in regions of high and low stellar density within Cygnus-X and find that the luminosity function in regions of high stellar density is biased to higher luminosities. In total, these observations provide further evidence that the luminosities of protostars depend on their natal environment. We discuss the implications this dependence has for the star formation process.

  9. THE TRIGONOMETRIC PARALLAX OF CYGNUS X-1

    SciTech Connect

    Reid, Mark J.; McClintock, Jeffrey E.; Narayan, Ramesh; Gou Lijun; Remillard, Ronald A.; Orosz, Jerome A.

    2011-12-01

    We report a direct and accurate measurement of the distance to the X-ray binary Cygnus X-1, which contains the first black hole to be discovered. The distance of 1.86{sup +0.12}{sub -0.11} kpc was obtained from a trigonometric parallax measurement using the Very Long Baseline Array. The position measurements are also sensitive to the 5.6 day binary orbit and we determine the orbit to be clockwise on the sky. We also measured the proper motion of Cygnus X-1 which, when coupled to the distance and Doppler shift, gives the three-dimensional space motion of the system. When corrected for differential Galactic rotation, the non-circular (peculiar) motion of the binary is only about 21 km s{sup -1}, indicating that the binary did not experience a large 'kick' at formation.

  10. A study of 2-20 KeV X-rays from the Cygnus region

    NASA Technical Reports Server (NTRS)

    Bleach, R. D.

    1972-01-01

    Two rocket-borne proportional counters, each with 650 sq c, met area and 1.8 x 7.1 deg FWHM rectangular mechanical collimation, surveyed the Cygnus region in the 2 to 20 keV energy range on two occasions. X-ray spectral data gathered on 21 September 1970 from discrete sources in Cygnus are presented. The data from Cyg X-1, Cyg X-2, and Cyg X-3 have sufficient statistical significance to indicate mutually exclusive spectral forms for the three. Upper limits are presented for X-ray intensities above 2 keV for Cyg X-4 and Cyg X-5 (Cygnus loop). A search was made on 9 August 1971 for a diffuse component of X-rays 1.5 keV associated with an interarm region of the galaxy at galactic longitudes in the vicinity of 60 degrees. A statistically significant excess associated with a narrow disk component was detected. Several possible emission models are discussed, with the most likely candidate being a population of unresolvable low luminosity discrete sources.

  11. Modeling the Infrared Emission from Cygnus A

    NASA Astrophysics Data System (ADS)

    Privon, George C.; Baum, S.; O'Dea, C.; Axon, D.; Robinson, A.; Gallimore, J.; Noel-Storr, J.

    2010-01-01

    The Spitzer Space Telescope provides a unique view of the Universe at infrared wavelengths. Improved sensitivity and angular resolution over previous missions enable detailed studies of astrophysical objects, both in imaging and spectroscopic modes. Spitzer observations of active galactic nuclei can help shed light on the physical conditions of the central regions of these active galaxies. The nearby radio galaxy Cygnus A is one of the most luminous radio sources in the local Universe. In addition to the high radio power, it is also very luminous in the infrared. New Spitzer spectroscopy and photometry of Cygnus A is combined with data from the literature at radio and sub-mm wavelengths. The resulting complication is modeled with a combination of: a synchrotron emitting jet, a burst of star formation, and emission from an AGN torus. The infrared emission in Cyngus A shows contributions from all three processes and the models are able to reproduce the observed emission over almost 5 dex in frequency. The bolometric AGN luminosity is found to be 1045 erg s-1, with a clumpy torus size of 7 pc. Evidence is seen for a break in the synchrotron spectrum in the mid-infrared. The relevant component of the infrared emission suggests Cygnus A has a star formation rate of 20 Msun yr-1. Even in the absence of the AGN, it would still be a luminous infrared source. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

  12. Is the Cygnus Superbubble a Hypernova Remnant?

    NASA Astrophysics Data System (ADS)

    Kimura, Masashi; Tsunemi, Hiroshi; Tomida, Hiroshi; Sugizaki, Mutsumi; Ueno, Shiro; Hanayama, Takanori; Yoshidome, Koshiro; Sasaki, Masayuki

    2013-02-01

    We present here an observation of the Cygnus Superbubble (CSB) using the Solid-state slit camera (SSC) aboard the Monitor of All-sky X-ray Image (MAXI). The CSB is a large diffuse structure in the Cygnus region with enhanced soft X-ray emission. By utilizing the CCD spectral resolution of the SSC, we detected Fe, Ne, Mg emission lines from the CSB for the first time. The best-fit model implies a thin hot plasma of kT ≈ 0.3 keV with a depleted abundance of 0.26±0.1 solar. Joint spectrum fittings of the ROSAT/PSPC data and MAXI/SSC data enabled us to measure precise values of NH and the temperature inside the CSB. The results show that all of the regions in the CSB have a similar NH and temperature, indicating that the CSB is a single unity. An energy budgets calculation suggests that (2-3) × 106 yr of stellar wind from the Cyg OB2 is sufficient to power up the CSB, whereas due to its off-center position, the origin of the CSB is most likely to be a Hypernova.

  13. The Cluster of Galaxies Surrounding Cygnus A

    NASA Astrophysics Data System (ADS)

    Owen, Frazer N.; Ledlow, Michael J.; Morrison, Glenn E.; Hill, John M.

    1997-10-01

    We report optical imaging and spectroscopy of 41 galaxies in a 22' square region surrounding Cygnus A. The results show that there is an extensive rich cluster associated with Cyg A of Abell richness of at least 1 and possibly as high as 4. The velocity histogram has two peaks, one centered on Cyg A and a more significant peak redshifted by about 2060 km s-1 from the velocity of Cyg A. The dynamical centroid of the spatial distribution is also shifted somewhat to the northwest. However, statistical tests show only weak evidence that there are two distinct clusters. The entire system has a velocity dispersion of 1581 km s-1, which is slightly larger than other, well-studied examples of rich clusters.

  14. New evidence from Soudan 1 for underground muons associated with Cygnus X-3

    SciTech Connect

    Ayres, D.S.

    1986-06-05

    The Soudan 1 experiment has obtained additional evidence for underground muons associated with the x-ray pulsar Cygnus X-3. We report the preliminary analysis of data recorded during the October 1985 radio outburst of Cygnus X-3, which show a significant excess of muons for a narrow range of Cygnus X-3 phases.

  15. Absorption dips at low X-ray energies in Cygnus X-1. [observed with Copernicus satellite

    NASA Technical Reports Server (NTRS)

    Murdin, P. G.

    1976-01-01

    Absorbing material in Cygnus X-1 jitters near the line joining the two stars, out of the orbital plane is described. Three looks with the Copernicus satellite at Cygnus X-1 have produced four examples of absorption dips (decreases in the 2 to 7 keV flux from Cygnus X-1 with an increase of spectral hardness consistent with photoelectric absorption).

  16. Young and embedded clusters in Cygnus-X: evidence for building up the initial mass function?

    NASA Astrophysics Data System (ADS)

    Maia, F. F. S.; Moraux, E.; Joncour, I.

    2016-05-01

    We provide a new view on the Cygnus-X north complex by accessing for the first time the low mass content of young stellar populations in the region. Canada-France-Hawaii Telescope/Wide-Field Infrared Camera was used to perform a deep near-infrared survey of this complex, sampling stellar masses down to ˜0.1 M⊙. Several analysis tools, including a extinction treatment developed in this work, were employed to identify and uniformly characterize a dozen unstudied young star clusters in the area. Investigation of their mass distributions in low-mass domain revealed a relatively uniform log-normal initial mass function (IMF) with a characteristic mass of 0.32 ± 0.08 M⊙ and mass dispersion of 0.40 ± 0.06. In the high-mass regime, their derived slopes showed that while the youngest clusters (age < 4 Myr) presented slightly shallower values with respect to the Salpeter's, our older clusters (4 Myr < age < 18 Myr) showed IMF compliant values and a slightly denser stellar population. Although possibly evidencing a deviation from an `universal' IMF, these results also supports a scenario where these gas-dominated young clusters gradually `build up' their IMF by accreting low-mass stars formed in their vicinity during their first ˜3 Myr, before the gas expulsion phase, emerging at the age of ˜4 Myr with a fully fledged IMF. Finally, the derived distances to these clusters confirmed the existence of at least three different star-forming regions throughout Cygnus-X north complex, at distances of 500-900 pc, 1.4-1.7 and 3.0 kpc, and revealed evidence of a possible interaction between some of these stellar populations and the Cygnus OB2 association.

  17. Multispectral analysis of Cygnus Loop and IC 443 with iFTS

    NASA Astrophysics Data System (ADS)

    Alarie, Alexandre

    2016-06-01

    Cygnus Loop and IC 443 are supernova remnants (SNRs) recognized as excellent laboratories to study the interaction between the SNR and the surrounding interstellar medium. The overall complex morphologies and large dimensions of those SNRs have always represented an observational challenge. This is especially true for optical observations for which the data available are very scarce. In order to palliate this scarcity in the optical regime, we are using two wide field-imaging Fourier transform spectrometers (iFTS): SpIOMM, attached to the Mont Megantic 1.6-m telescope and SITELLE recently installed at the Canada-France-Hawaii Telescope. Both instruments are capable of obtaining the spatially resolved visible spectrum of every source of light in an 11 arc minute field of view, in selected bandpasses. Using those iFTS on extended object such as Cygnus Loop and IC 443, we have obtained millions of spectra covering all major emission lines. Due to the large projected surface of Cygnus Loop and IC 443, we started a survey and the latest dataset will be presented. The extended 2D mappings of several emission lines ([O II] 3727, [O III] 4363, Hb, [O III] 4959, 5007, Ha, [N II] 6548, 6583 and [S II] 6716, 6731) allowed the creation of numerous ratios maps useful for shock diagnostics: shock velocity, electronic and temperature densities, location of incomplete shocks and extinction maps. These maps are then used to determine key parameters needed to compare the observations with theoretical shock models. Using the shock modeling code MAPPINGS, we can create abundances maps of nitrogen, oxygen and sulfur for an appreciable fraction of the observed regions. Furthermore, using the radial velocity as well as the spectro-imagery capability of the iFTS, we can have a glimpse of the three-dimensional structure of the remnants. All those data allow us to forge a coherent analysis of the complex interaction between the SNRs and their surrounding environment.

  18. Non-Thermal Emission from the massive stellar association Cygnus OB2

    NASA Astrophysics Data System (ADS)

    Fenech, Danielle Marie; Prinja, Raman; Morford, Jack

    2015-08-01

    The Cygnus OB2 association is located in the Galactic Cygnus X region at a distance of 1.4 kpc, making it one of the closest young massive stellar clusters. Cyg OB2 is not only very rich in stellar density but also in its diversity. It is known to contain a rich population of massive stars including almost 2600 OB stars, a large number of binaries (including a collection of some of the most interesting radio emitting colliding-wind binaries), and a considerable number of pre-main sequence stars.We report here on the first results from The Cyg OB2 Radio Survey (COBRaS), which is a UCL-led e-MERLIN legacy project to provide a deep-field radio mapping of the Cygnus OB2 association. The project has been awarded a total allocation of 252 hours at C-band (5GHz) and 42 hours at L-band (1.6GHz) to image the core of the cluster.We discuss in particular the presence of non-thermal radio emission at 20 cm (L-band), and its potential as a highly efficient way to identify binaries via single-epoch observations, particularly for colliding-wind binaries. COBRaS data will provide a powerful tool for establishing binary incidence in Cyg~OB2, specifically in the difficult intermediate-period range (1--100~yr). Knowing the binary frequency over the whole period range is important for population synthesis.Additionally, Weak-lined T Tauri (WTT) stars in Cyg OB2 also emit non-thermal radiation from magnetically active regions. Hence these observations will be used to detect the considerable population of younger stars.Ultimately, we aim to assemble a substantial and uniquely sensitive radio dataset, which will be exploited to address several fundamentally important areas of stellar astrophysics, including mass-loss, binary frequency, stellar cluster dynamics, and triggered star-formation.

  19. A discussion of the H-alpha filamentary nebulae and galactic structure in the Cygnus region

    NASA Technical Reports Server (NTRS)

    Matthews, T. A.; Simonson, S. C., III

    1971-01-01

    From observation of the galactic structure in Cygnus, the system of filamentary nebulae was found to lie at a distance of roughly 1.5 kpc, in the same region as about half the thermal radio sources in Cygnus X, the supernova remnant near gamma Cygni, and the association Cygnus OB2, in the direction of which the X-ray source Cygnus XR-3 is observed. The source of excitation was probably the pulse of radiation from a supernova explosion, as proposed in the case of Gum nebula. However continuing excitation by early stars in the region of Cygnus X cannot be excluded.

  20. XMM-Newton observations of CYGNUS X-1

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard F. (Technical Monitor); Miller, Jon

    2005-01-01

    Observations of Cygnus X-1 were first attempted under this program in the spring of 2004, but were complicated by instrumental flaring problems. Successful observations were completed in the fall of 2004, and processed data were delivered to the PI in the winter and spring of 2005. Thus, focused work on this data was only possible starting in 2005. A preliminary reduction and analysis of data from the EPIC CCD cameras and the Reflection Grating Spectrometer has been made. The EPIC spectra reveal the best example of a broadened, relativistic iron emission line yet found in Cygnus X-1. The Oxygen K-shell region has been shown to be a very complex wavelength range in numerous spectra of accreting sources, but the RGS spectra reveal this region in great detail and will be important in understanding the wind from the 0-type donor star that is focused onto the black hole in Cygnus X-1.

  1. VERITAS Observations of the Cygnus Region of the Galaxy

    NASA Astrophysics Data System (ADS)

    Bird, Ralph; VERITAS Collaboration

    2016-03-01

    The Cygnus region is a very active region of our Galaxy, with many sources of GeV and TeV gamma-ray emission, such as supernova remnants, pulsar wind nebulae, high mass X-ray binaries and massive star clusters. A detailed study of the Cygnus region can give insight into the processes of particle acceleration in astrophysical sources. VERITAS is an array of four 12-meter diameter imaging atmospheric Cherenkov telescopes located at Mt. Hopkins, AZ, USA. From 2007 through 2012 nearly 300 hours of data was gathered in the Cygnus region, covering 67 to 83 degrees Galactic longitude and -2 to 5 degrees in Galactic latitude. An update of the Fermi-LAT and VERITAS analysis of this region is presented. In particular we examine the source and hotspot regions within the Milagro dataset covering this region and the comparison between these objects in the three different instruments.

  2. Satellite tracking of the migration of Whooper Swans Cygnus cygnus wintering in Japan

    USGS Publications Warehouse

    Shimada, Tetsuo; Yamaguchi, Noriyuki M.; Hijikata, N.; Hiraoka, Emiko N.; Hupp, Jerry; Flint, Paul L.; Tokita, Ken-ichi; Fujita, Go; Uchida, Kiyoshi; Sato, F.; Kurechi, Masayuki; Pearce, John M.; Ramey, Andy M.; Higuchi, Hiroyoshi

    2014-01-01

    We satellite-tracked Whooper Swans Cygnus cygnus wintering in northern Japan to document their migration routes and timing, and to identify breeding areas. From 47 swans that we marked at Lake Izunuma-Uchinuma, Miyagi Prefecture, northeast Honshu, and at Lake Kussharo, east Hokkaido, we observed 57 spring and 33 autumn migrations from 2009-2012. In spring, swans migrated north along Sakhalin Island from eastern Hokkaido using stopovers in Sakhalin, at the mouth of the Amur River and in northern coastal areas of the Sea of Okhotsk. They ultimately reached molting/breedmg areas along the Indigirka River and the lower Kolyma River in northern Russia. In autumn, the swans basically reversed the spring migration routes. We identified northern Honshu, eastern Hokkaido, coastal areas in Sakhalin, the lower Amur River and northern coastal areas of the Sea of Okhotsk as the most frequent stopover sites, and the middle reaches of the Indigirka and the lower Kolyma River as presumed breeding sites. Our results are helpful in understanding the distribution of the breeding and stopover sites of Whooper Swans wintering in Japan and in identifying their major migration habitats. Our findings contribute to understanding the potential transmission process of avian influenza viruses potentially carried by swans, and provide information necessary to conserve Whooper Swans in East Asia.

  3. Characterization of microsatellite loci isolated in trumpeter swan (Cygnus buccinator)

    USGS Publications Warehouse

    John, J. St; Ransler, F.A.; Quinn, T.W.; Oyler-McCance, S.J.

    2006-01-01

    Primers for 16 microsatellite loci were developed for the trumpeter swan (Cygnus buccinator), a species recovering from a recent population bottleneck. In a screen of 158 individuals, the 16 loci were found to have levels of variability ranging from two to seven alleles. No loci were found to be linked, although two loci repeatedly revealed significant departures from Hardy-Weinberg equilibrium. Amplification in the closely related tundra swan (Cygnus columbianus) was successful for all except one locus. These microsatellite loci will be applicable for population genetic analyses and ultimately aid in management efforts. ?? 2006 The Authors.

  4. NIR Variable YSOs in Cygnus OB7 and the ONC

    NASA Astrophysics Data System (ADS)

    Wolk, Scott; Rice, Thomas; Aspin, Colin

    2013-07-01

    We present an analysis of near-infrared time-series photometry in J, H, and K bands for about 100 epochs, mostly focusing on a 1x1 degree region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. Augmented by data from the Wide-field Infrared Survey Explorer (WISE), we identify 96 candidate disk bearing young stellar objects (YSOs) in the region. Of these, 30 are clearly Class I or earlier. Using the Wide-Field imaging CAMera (WFCAM) on the United Kingdom InfraRed Telescope (UKIRT), we obtained photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J ~ 17. We study detailed light curves and color trajectories of ~50 of the YSOs in the monitored field. We investigate the variability and periodicity of the YSOs and find the data are consistent with all YSOs being variable in these wavelengths on time scales of a few years. We divide the variability into four observational classes: 1) stars with periodic variability stable over long timescales, 2) variables which exhibit short-lived cyclic behavior, 3) long duration variables, and 4) stochastic variables. Some YSO variability defies simple classification. We can explain much of the observed variability as being due to dynamic and rotational changes in the disk, including an asymmetric or changing blocking fraction, changes to the inner disk hole size, as well as changes to the accretion rate. Overall, we find that the Class I:Class II ratio of the cluster is consistent with an age of < 1 Myr, with at least one individual, wildly varying, source ~100,000 yr old. We have also discovered a Class~II eclipsing binary system with a period of 17.87 days. Preliminary statistical results for the ONC are also presented.

  5. PHOTOEVAPORATING PROPLYD-LIKE OBJECTS IN CYGNUS OB2

    SciTech Connect

    Wright, Nicholas J.; Drake, Jeremy J.; Guarcello, Mario G.; Hora, Joseph L.; Drew, Janet E.; Gutermuth, Robert A.; Kraemer, Kathleen E.

    2012-02-20

    We report the discovery of 10 proplyd-like objects in the vicinity of the massive OB association Cygnus OB2. They were discovered in IPHAS H{alpha} images and are clearly resolved in broadband Hubble Space Telescope/Advanced Camera for Surveys, near-IR, and Spitzer mid-IR images. All exhibit the familiar tadpole shape seen in photoevaporating objects such as the Orion proplyds, with a bright ionization front at the head facing the central cluster of massive stars and a tail stretching in the opposite direction. Many also show secondary ionization fronts, complex tail morphologies, or multiple heads. We consider the evidence that these are either proplyds or 'evaporating gaseous globules' (EGGs) left over from a fragmenting molecular cloud, but find that neither scenario fully explains the observations. Typical sizes are 50,000-100,000 AU, larger than the Orion proplyds, but in agreement with the theoretical scaling of proplyd size with distance from the ionizing source. These objects are located at projected separations of {approx}6-14 pc from the OB association, compared to {approx}0.1 pc for the Orion proplyds, but are clearly being photoionized by the {approx}65 O-type stars in Cyg OB2. Central star candidates are identified in near- and mid-IR images, supporting the proplyd scenario, though their large sizes and notable asymmetries are more consistent with the EGG scenario. A third possibility is therefore considered that these are a unique class of photoevaporating partially embedded young stellar objects that have survived the destruction of their natal molecular cloud. This has implications for the properties of stars that form in the vicinity of massive stars.

  6. FIVE MORE MASSIVE BINARIES IN THE CYGNUS OB2 ASSOCIATION

    SciTech Connect

    Kiminki, Daniel C.; Kobulnicky, Henry A.; Gilbert, Ian; Bird, Sarah; Chunev, Georgi

    2009-06-15

    We present the orbital solutions for four OB spectroscopic binaries, MT145, GSC 03161 - 00815, 2MASS J20294666+4105083, and Schulte 73, and the partial orbital solution to the B spectroscopic binary, MT372, as part of an ongoing study to determine the distribution of orbital parameters for massive binaries in the Cygnus OB2 Association. MT145 is a new, single-lined, moderately eccentric (e = 0.291 {+-} 0.009) spectroscopic binary with period of 25.140 {+-} 0.008 days. GSC 03161 - 00815 is a slightly eccentric (e = 0.10 {+-} 0.01), eclipsing, interacting and double-lined spectroscopic binary with a period of 4.674 {+-} 0.004 days. 2MASS J20294666+4105083 is a moderately eccentric (e = 0.273 {+-} 0.002) double-lined spectroscopic binary with a period of 2.884 {+-} 0.001 days. Schulte 73 is a slightly eccentric (e = 0.169 {+-} 0.009), double-lined spectroscopic binary with a period of 17.28 {+-} 0.03 days and the first 'twin' in our survey with a mass ratio of q = 0.99 {+-} 0.02. MT372 is a single-lined, eclipsing system with a period of 2.228 days and low eccentricity (e {approx} 0). Of the now 18 known OB binaries in Cyg OB2, 14 have periods and mass ratios. Emerging evidence also shows that the distribution of log(P) is flat and consistent with 'Oepik's Law'.

  7. Global far-ultraviolet properties of the Cygnus Loop

    SciTech Connect

    Kim, Il-Joong; Seon, Kwang-Il; Lee, Dae-Hee; Han, Wonyong; Lim, Yeo-Myeong; Min, Kyoung-Wook; Edelstein, Jerry

    2014-03-20

    We present the C III λ977, O VI λλ1032, 1038 and N IV] λ1486 emission line maps of the Cygnus Loop, obtained with the newly processed data of the Spectroscopy of Plasma Evolution from Astrophysical Radiation (SPEAR; also known as FIMS) mission. In addition, the Si IV+O IV] line complexes around 1400 Å are resolved into two separate emission lines whose intensity demonstrates a relatively high Si IV region that was predicted in the previous study. The morphological similarity between the O VI and X-ray images, as well as a comparison of the O VI intensity with the value expected from the X-ray results, indicates that large portions of the observed O VI emissions could be produced from X-ray emitting gas. Comparisons of the far-ultraviolet (FUV) images with the optical and H I 21 cm images reveal spatial variations of shock-velocity populations and high FUV extinction in the direction of a previously identified H I cloud. By calculating the FUV line ratios for several subregions of the Cygnus Loop, we investigate the spatial variation of the population of radiative shock velocities as well as the effects of resonance scattering, X-ray emitting gas, and nonradiative shocks. The FUV and X-ray luminosity comparisons between the Cygnus Loop and the Vela supernova remnant suggest that the fraction of shocks in the early evolutionary stages is much larger in the Cygnus Loop.

  8. LINE-OF-SIGHT SHELL STRUCTURE OF THE CYGNUS LOOP

    SciTech Connect

    Uchida, Hiroyuki; Tsunemi, Hiroshi; Katsuda, Satoru; Kimura, Masashi; Kosugi, Hiroko; Takahashi, Hiroaki

    2009-11-10

    We conducted a comprehensive study on the shell structure of the Cygnus Loop using 41 observation data obtained by the Suzaku and the XMM-Newton satellites. To investigate the detailed plasma structure of the Cygnus Loop, we divided our fields of view into 1042 box regions. From the spectral analysis, the spectra obtained from the limb of the Loop are well fitted by the single-component non-equilibrium ionization plasma model. On the other hand, the spectra obtained from the inner regions are well fitted by the two-component model. As a result, we confirmed that the low-temperature and high-temperature components originated from the surrounding interstellar matter (ISM) and the ejecta of the Loop, respectively. From the best-fit results, we showed a flux distribution of the ISM component. The distribution clearly shows the limb-brightening structure, and we found out some low-flux regions. Among them, the south blowout region has the lowest flux. We also found other large low-flux regions at slightly west and northeast from the center. We estimated the former thin shell region to be approx1.{sup 0}3 in diameter and concluded that there exists a blowout along the line of sight in addition to the south blowout. We also calculated the emission measure distribution of the ISM component and showed that the Cygnus Loop is far from the result obtained by a simple Sedov evolution model. From the results, we support that the Cygnus Loop originated from a cavity explosion. The emission measure distribution also suggests that the cavity-wall density is higher in the northeast than that in the southwest. These results suggest that the thickness of the cavity wall surrounding the Cygnus Loop is not uniform.

  9. Cygnus X-3: Its Little Friend’s Counterpart, the Distance to Cygnus X-3, and Outflows/Jets

    NASA Astrophysics Data System (ADS)

    McCollough, M. L.; Corrales, L.; Dunham, M. M.

    2016-10-01

    Chandra observations have revealed a feature within 16″ of Cygnus X-3 that varied in phase with Cygnus X-3. This feature was shown to be a Bok globule that is along the line of sight to Cygnus X-3. We report on observations made with the Submillimeter Array to search for molecular emission from this globule, also known as Cygnus X-3's “Little Friend.” We have found a counterpart in both 12CO (2-1) and 13CO (2-1) emission. From the velocity shift of the molecular lines we are able to find two probable distances based on the Bayesian model of Milky Way kinematics of Reid et al. For the LF velocity of ‑47.5 km s‑1, we find distances of 6.1 ± 0.6 kpc (62% probability) and 7.8 ± 0.6 kpc (38% probability). This yields distances to Cyg X-3 of 7.4 ± 1.1 kpc and 10.2 ± 1.2 kpc, respectively. Based on the probabilities entailed, we take 7.4 ± 1.1 kpc as the preferred distance to Cyg X-3. We also report the discovery of bipolar molecular outflow, suggesting that there is active star formation occurring within the Little Friend.

  10. Continuum and line emission in Cygnus A

    NASA Astrophysics Data System (ADS)

    Stockton, Alan; Ridgway, Susan E.; Lilly, Simon J.

    1994-08-01

    We present the results from (1) imaging observations of Cygnus A in five essentially line-free continuum bands with central wavelengths ranging from 0.34 to 2.1 microns. (2) imaging observations in five narrowband filters centered on the emission lines H beta(O III) lambda5007, H alpha(N II) lambda6583, and (S II) lambda lambda6716, 6731, and (3) deep spectroscopy covering the entire central region of Cyg A. We confirm that the featureless spectrum component is to be identified with the prominent double morphology at the center of Cyg A, but uncertainties in the distribution of the dust in this region tend to limit the accuracy with which we can determine its morphology and spectral-energy distribution (SED). From regions that appear to be least affected by obscuration, we find fv is approximately v-0.1 for this component. This SED could be consistent with free-free emission, a population of young stars, or a quasar continuum scattered by electrons, but probably not with a quasar continuum scattered by dust, which would be bluer. Our spectroscopy places an upper limit on the equivalent width of broad H beta that is well below that of typical quasars, showing that this flat-spectrum component (FSC) is almost certainly not dominated by scattered quasar radiation. Appeals to scattering by hot electrons to smear the scattered broad lines into invisibility appear to fail because the large density scale height of the electrons and the inefficiency of electron scattering should result in smoother and more extensive structure than we observe. Although the relative SED is consistent with free-free emission, the required amount of hot gas violates other observational constraints. At high angular resolution, the apparent morphology of the FSC is spiral-like. Although this impression may be partly due to obscuration, the distribution of the dust itself only serves to reinforce the spiral-like nature of the material with which it is associated. We conclude that the FSC is most

  11. Cygnus Pressured Cargo Module: Validation of Mathematical Model and Dynamic Qualification of Secondary Structures

    NASA Astrophysics Data System (ADS)

    Bellini, Marina; Luison, Dario; Tizzani, Luca

    2012-07-01

    Thales Alenia Space Italy is in charge to develop build- up, integrate and verify Cygnus Pressurized Cargo Module (PCM). This cargo is characterized by the large amount of payload, wrapped in foam, transferred in soft stowage bags, connected to the structure of support by belts. The paper summarizes the several tests performed to acquire the dynamic properties of bags. On the basis of the empirical results a reliable linear model was generated and used for a successful campaign of qualification of secondary structure. It is also demonstrated that the empirical-linear model of the soft-stowage bag was also the reason of a significant reduction of loads, which allowed achieving more easily the goal of carried mass, for PCM. The validation of PCM by Modal Survey Test is presented as well, emphasizing that the more realistic modeling of the soft bags has made easier the definition of a very simple test configuration.

  12. VizieR Online Data Catalog: Millimeter continuum mapping of Cygnus X (Motte+, 2007)

    NASA Astrophysics Data System (ADS)

    Motte, F.; Bontemps, S.; Schilke, P.; Schneider, N.; Menten, K. M.; Broguiere, D.

    2007-09-01

    We report on a millimeter continuum survey of the entire Cygnus X molecular complex. We used the MAMBO and MAMBO-2 bolometer arrays on the IRAM 30m telescope to map a 3deg2 area at 1.2mm (see fits files of Figures 2, kept to 11" resolution). Our MAMBO-2 imaging gives a complete view of the cloud structures ranging from 0.03pc to 5pc, i.e. from dense cores to clumps. We perform a multi-resolution analysis to extract 129 compact dense cores (~0.1pc, see Table 1) and identify 40 massive large-scale clumps (~0.7pc, see Table 2). The 21um fluxes arising from dense cores are taken from the MSX point source catalog (MSX C6, Cat. ). (5 data files).

  13. Shocked and Scorched: Free-Floating Evaporating Gas Globules and Star Formation in Cygnus

    NASA Astrophysics Data System (ADS)

    Sahai, Raghvendra; Claussen, M. J.; Morris, M. R.

    2012-05-01

    We report molecular line observations of a new class of Free-floating Evaporating Gas Globules with tadpole shapes (i.e., FrEGGs), recently discovered in the Cygnus star-forming region. We serendipitously found two of these in an HST imaging survey, including one of the most prominent members of this class (IRAS20324+4057: the Tadpole). Our molecular-line observations, carried out with the Arizona Radio Observatory's mm-wave telescopes, include on-the-fly maps in the CO and 13CO J=2-1 lines as well as pointed observations in the J=3-2 line of the high-density tracers HCO+ and N2H+. These data show the presence of dense molecular cores with total masses of cold molecular gas exceeding one to a few Msun in almost all FrEGGs. Our radio continuum imaging of 3 FrEGGs, as well as Halpha images from the IPHAS survey reveal bright photo-ionized peripheries around these objects. We infer that FrEGGs are dense, star-forming molecular cores that originated in the Cygnus cloud and are now being photoevaporated by the ultraviolet radiation field of the Cyg OB2 cluster, and shaped by the ram pressure of strong wind sources. The extended tails in some of the largest objects show wiggles likely resulting from Kelvin-Helmoltz instabilities. We find evidence for non-thermal radio emission in the Tadpole, with the radio emission peaking strongly along the shock/ionization front at its head, possibly as a result of a compressed magnetic layer in this front that is interacting with cosmic rays associated with the Cyg OB2 association.

  14. VERITAS Observations of the Microquasar Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Archambault, S.; Beilicke, M.; Benbow, W.; Berger, K.; Bird, R.; Bouvier, A.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M. P.; Cui, W.; Duke, C.; Dumm, J.; Errando, M.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Fortson, L.; Furniss, A.; Galante, N.; Gillanders, G. H.; Griffin, S.; Griffiths, S. T.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Hughes, G.; Humensky, T. B.; Kaaret, P.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Lang, M. J.; Madhavan, A. S.; Maier, G.; Majumdar, P.; McArthur, S.; McCann, A.; Moriarty, P.; Mukherjee, R.; Nieto, D.; O'Faoláin de Bhróithe, A.; Ong, R. A.; Otte, A. N.; Pandel, D.; Park, N.; Perkins, J. S.; Pohl, M.; Popkow, A.; Prokoph, H.; Quinn, J.; Ragan, K.; Rajotte, J.; Reyes, L. C.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Sembroski, G. H.; Sheidaei, F.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Theiling, M.; Tucci, J. V.; Tyler, J.; Varlotta, A.; Vincent, S.; Wakely, S. P.; Weekes, T. C.; Weinstein, A.; Williams, D. A.; Zitzer, B.; VERITAS Collaboration and; McCollough, M. L.; Astrophysical Observatory, Smithsonian

    2013-12-01

    We report results from TeV gamma-ray observations of the microquasar Cygnus X-3. The observations were made with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) over a time period from 2007 June 11 to 2011 November 28. VERITAS is most sensitive to gamma rays at energies between 85 GeV and 30 TeV. The effective exposure time amounts to a total of about 44 hr, with the observations covering six distinct radio/X-ray states of the object. No significant TeV gamma-ray emission was detected in any of the states, nor with all observations combined. The lack of a positive signal, especially in the states where GeV gamma rays were detected, places constraints on TeV gamma-ray production in Cygnus X-3. We discuss the implications of the results.

  15. Discovery of a Radio Transient in Cygnus A

    NASA Astrophysics Data System (ADS)

    Perley, D. A.; Perley, R. A.; Carilli, C. L.

    2016-09-01

    We report the detection of a new radio source close to the nucleus of Cygnus A. Observations taken with the Very Large Array at frequencies between 8-20 GHz in July 2015, and between 20-50 GHz in August 2016, reveal a point source at the following location (J2000): RA = 19:59:28.32385 Dec = +40:44:01.9165 The source is detected at all frequencies and cleanly resolved from the Cygnus A nucleus; the separation is 0.395" (=430 pc). The positional accuracy (as registered against the nucleus) is approximately 3 mas. The flux density of this source is 4 mJy at 10 GHz, with a spectral index of alpha ~ -0.2 (F_nu ~ nu^alpha).

  16. Veritas observations of the microquasar Cygnus X-3

    SciTech Connect

    Archambault, S.; Beilicke, M.; Buckley, J. H.; Bugaev, V.; Benbow, W.; Cerruti, M.; Berger, K.; Bird, R.; Bouvier, A.; Byrum, K.; Chen, X.; Federici, S.; Ciupik, L.; Connolly, M. P.; Cui, W.; Feng, Q.; Duke, C.; Dumm, J.; Errando, M.; Falcone, A. E-mail: cui@purdue.edu; Collaboration: VERITAS Collaboration) and; Smithsonian Astrophysical Observatory; and others

    2013-12-20

    We report results from TeV gamma-ray observations of the microquasar Cygnus X-3. The observations were made with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) over a time period from 2007 June 11 to 2011 November 28. VERITAS is most sensitive to gamma rays at energies between 85 GeV and 30 TeV. The effective exposure time amounts to a total of about 44 hr, with the observations covering six distinct radio/X-ray states of the object. No significant TeV gamma-ray emission was detected in any of the states, nor with all observations combined. The lack of a positive signal, especially in the states where GeV gamma rays were detected, places constraints on TeV gamma-ray production in Cygnus X-3. We discuss the implications of the results.

  17. Cygnus X-2 in a radio quiet state

    NASA Astrophysics Data System (ADS)

    Rushton, A.; Bach, U.; Spencer, R.; Kadler, M.; Church, M.; Balucinska-Church, M.; Wilms, J.; Hanke, M.; Zola, S.; Schulz, N.

    2009-05-01

    The neutron star X-ray binary Cygnus X-2 was observed using the e- EVN (European VLBI Network) on May 12/13th 2009 between 23:00-13:00 UT at 5 GHz. The radio telescopes participating with the e-EVN at 5 GHz were Effelsberg, Medicina, Onsala 25m, Torun, Sheshan, Yebes, Jodrell Bank MKII, Cambridge and Knockin. A maximum data rate of 1024 Mbps were achieved from four telescopes (Effelsberg, Onsala, Torun and Jodrell Bank MKII).

  18. Globules and pillars in Cygnus X. I. Herschel far-infrared imaging of the Cygnus OB2 environment

    NASA Astrophysics Data System (ADS)

    Schneider, N.; Bontemps, S.; Motte, F.; Blazere, A.; André, Ph.; Anderson, L. D.; Arzoumanian, D.; Comerón, F.; Didelon, P.; Di Francesco, J.; Duarte-Cabral, A.; Guarcello, M. G.; Hennemann, M.; Hill, T.; Könyves, V.; Marston, A.; Minier, V.; Rygl, K. L. J.; Röllig, M.; Roy, A.; Spinoglio, L.; Tremblin, P.; White, G. J.; Wright, N. J.

    2016-06-01

    The radiative feedback of massive stars on molecular clouds creates pillars, globules and other features at the interface between the H II region and molecular cloud. Optical and near-infrared observations from the ground as well as with the Hubble or Spitzer satellites have revealed numerous examples of such cloud structures. We present here Herschel far-infrared observations between 70 μm and 500 μm of the immediate environment of the rich Cygnus OB2 association, performed within the Herschel imaging survey of OB Young Stellar objects (HOBYS) program. All of the observed irradiated structures were detected based on their appearance at 70 μm, and have been classified as pillars, globules, evaporating gasous globules (EGGs), proplyd-like objects, and condensations. From the 70 μm and 160 μm flux maps, we derive the local far-ultraviolet (FUV) field on the photon dominated surfaces. In parallel, we use a census of the O-stars to estimate the overall FUV-field, that is 103-104 G0 (Habing field) close to the central OB cluster (within 10 pc) and decreases down to a few tens G0, in a distance of 50 pc. From a spectral energy distribution (SED) fit to the four longest Herschel wavelengths, we determine column density and temperature maps and derive masses, volume densities and surface densities for these structures. We find that the morphological classification corresponds to distinct physical properties. Pillars and globules are massive (~500 M⊙) and large (equivalent radius r ~ 0.6 pc) structures, corresponding to what is defined as "clumps" for molecular clouds. EGGs and proplyd-likeobjects are smaller (r ~ 0.1 and 0.2 pc) and less massive (~10 and ~30 M⊙). Cloud condensations are small (~0.1 pc), have an average mass of 35 M⊙, are dense (~6 × 104 cm-3), and can thus be described as molecular cloud "cores". All pillars and globules are oriented toward the Cyg OB2 association center and have the longest estimated photoevaporation lifetimes, a few million

  19. Catching a Galactic Football: Chandra Examines Cygnus A

    NASA Astrophysics Data System (ADS)

    2000-11-01

    Using NASA's Chandra X-ray Observatory, astronomers have found a giant football-shaped cavity within X-ray emitting hot gas surrounding the galaxy Cygnus A. The cavity in the hot gas has been created by two powerful jets emitted from the central black hole region in the nucleus of Cygnus A. Hot gas is steadily being piled up around the cavity as it continuously expands, creating a bright rim of X-ray emission. The jets themselves terminate in radio and X-ray emitting "hot spots" some 300,000 light years from the center of the galaxy. These results are being presented to the High Energy Astrophysics Division of the American Astronomical Society meeting in Honolulu, HI, by Andrew S. Wilson, Andrew J. Young (University of Maryland) and Patrick L. Shopbell (California Institute of Technology). "This is a spectacular cavity, which is inflated by jets and completely surrounds the Cygnus A galaxy," said Dr. Wilson, who is Professor of Astronomy at the University of Maryland, College Park. "We are witnessing a battle between the gravity of the Cygnus A galaxy, which is trying to pull the hot gas inwards, and the pressure of material created by the jets, which is trying to push the hot gas outwards." Cygnus A has long been famous as the brightest radio source in the sky. It is the nearest powerful radio galaxy. The Chandra X-ray image, which was taken with the Advanced CCD Imaging Spectrometer (ACIS), shows the cavity surrounded by a vast sea of extremely hot gas. The elongated oval shape comes from the force of the outwardly moving jets as they push through the hot gas. Bright bands around the "equator of the football" are also visible, and this may be evidence of material swirling toward the central black hole. Cygnus A Illustration Illustration of Cygnus A Credit: CXC Without the jets, an X-ray image of Cygnus A, which is about 700 million light years from Earth, would appear as a more or less spherical region (about 2 million light years across) of hot gas slowly

  20. Extreme particle acceleration in the microquasar Cygnus X-3.

    PubMed

    Tavani, M; Bulgarelli, A; Piano, G; Sabatini, S; Striani, E; Evangelista, Y; Trois, A; Pooley, G; Trushkin, S; Nizhelskij, N A; McCollough, M; Koljonen, K I I; Pucella, G; Giuliani, A; Chen, A W; Costa, E; Vittorini, V; Trifoglio, M; Gianotti, F; Argan, A; Barbiellini, G; Caraveo, P; Cattaneo, P W; Cocco, V; Contessi, T; D'Ammando, F; Del Monte, E; De Paris, G; Di Cocco, G; Di Persio, G; Donnarumma, I; Feroci, M; Ferrari, A; Fuschino, F; Galli, M; Labanti, C; Lapshov, I; Lazzarotto, F; Lipari, P; Longo, F; Mattaini, E; Marisaldi, M; Mastropietro, M; Mauri, A; Mereghetti, S; Morelli, E; Morselli, A; Pacciani, L; Pellizzoni, A; Perotti, F; Picozza, P; Pilia, M; Prest, M; Rapisarda, M; Rappoldi, A; Rossi, E; Rubini, A; Scalise, E; Soffitta, P; Vallazza, E; Vercellone, S; Zambra, A; Zanello, D; Pittori, C; Verrecchia, F; Giommi, P; Colafrancesco, S; Santolamazza, P; Antonelli, A; Salotti, L

    2009-12-01

    Super-massive black holes in active galaxies can accelerate particles to relativistic energies, producing jets with associated gamma-ray emission. Galactic 'microquasars', which are binary systems consisting of a neutron star or stellar-mass black hole accreting gas from a companion star, also produce relativistic jets, generally together with radio flares. Apart from an isolated event detected in Cygnus X-1, there has hitherto been no systematic evidence for the acceleration of particles to gigaelectronvolt or higher energies in a microquasar, with the consequence that we are as yet unsure about the mechanism of jet energization. Here we report four gamma-ray flares with energies above 100 MeV from the microquasar Cygnus X-3 (an exceptional X-ray binary that sporadically produces radio jets). There is a clear pattern of temporal correlations between the gamma-ray flares and transitional spectral states of the radio-frequency and X-ray emission. Particle acceleration occurred a few days before radio-jet ejections for two of the four flares, meaning that the process of jet formation implies the production of very energetic particles. In Cygnus X-3, particle energies during the flares can be thousands of times higher than during quiescent states. PMID:19935645

  1. Consolidating the Cygnus Region 1.809 MeV Emission

    NASA Technical Reports Server (NTRS)

    Oberlack, Uwe

    2000-01-01

    The analysis of additional Cygnus observations together with a further improved background model resulted in an update of the 1.809 MeV allsky map. Along with improvements of the data, the Cygnus region has been studied in greater detail and compared to a model of non-stationary nucleosynthesis following the evolution of young OB associations. This model has been vastly extended to include additional observables such as dynamics of the interstellar medium (ISM), following the evolution of superbubbles, and the emission of ionizing ultraviolet light. The rich OB associations Cygnus OB 1 and OB 2 could indeed account for a large fraction of the 'Cygnus West' emission. Emission from 'Cygnus East' however, cannot easily be modelled by the sparse Cygnus OB 7 association. This led to a study on the impact of a newly proposed Al-26 source, massive close binaries. It is found that a very significant Al-26 contribution from massive close binaries would be needed to account for the observed emission in Cygnus East, which would single out this region from other observations. It appears more likely that deeper observations (e.g., in the near infrared) are needed to get a better estimate on the population of massive stars in Cygnus East.

  2. PREFACE: CYGNUS 2013: 4th Workshop on Directional Detection of Dark Matter

    NASA Astrophysics Data System (ADS)

    Naka, Tatsuhiro; Miuchi, Kentaro

    2013-12-01

    It is a great pleasure to publish the proceedings of the 4th Workshop on Directional Detection of Dark Matter held in Toyama, Japan on 10-12 June 2013 (CYGNUS 2013). These proceedings contain written versions of the presentations made at CYGNUS 2013 as scientific outputs of the directional detection of dark matter. The GYGNUS workshop started in 2007 at Boulby Underground Laboratory (UK), followed by CYGNUS 2009 (MIT in Cambridge, Massachusetts, USA) and CYGNUS 2011 (AUSSOIS, France). CYGNUS 2013 was held by the combination of a two and a half days of scientific program and a half day visit to the underground laboratory (Kamioka Observatory) as a 'tradition' of CYGNUS workshops. The name 'CYGNUS' came from the fact that the 'dark matter wind' is expected to come from the direction of the constellation Cygnus due to the motion of the Solar system in the galaxy. A general aim of these CYGNUS workshops is to bring together the theoretical and experimental studies on the directional dark matter detection. Directional detection of dark matter is a promising approach to a 'clear detection' and also to 'further investigations' of galactic dark matter, or Weakly Interacting Massive Particles (WIMPs). Directional detection requires the simultaneous detection of the energy and track of low energy recoils. Among many technological challenges for the requirement above, three of them, namely size, background, and directionality (angular resolution and head-tail detection), are most important to demonstrate and improve the quality as a dark matter detector. In the workshop, up-to-date activities by the international reserchers are discussed. The workshop was a great success thanks to the oral contributions and fruitful discussions held throughout the workshop period. We hope that readers will remember and share the great enthusiasm shown during the CYGNUS 2013 workshop. The Editors Tatsuhiro Naka and Kentaro Miuchi

  3. ADDITIONAL MASSIVE BINARIES IN THE CYGNUS OB2 ASSOCIATION

    SciTech Connect

    Kiminki, Daniel C.; Kobulnicky, Henry A.; Ewing, Ian; Lundquist, Michael; Alexander, Michael; Vargas-Alvarez, Carlos; Choi, Heather; Bagley Kiminki, Megan M.; Henderson, C. B.

    2012-03-01

    We report the discovery and orbital solutions for two new OB binaries in the Cygnus OB2 Association, MT311 (B2V + B3V) and MT605 (B0.5V + B2.5:V). We also identify the system MT429 as a probable triple system consisting of a tight eclipsing 2.97 day B3V+B6V pair and a B0V at a projected separation of 138 AU. We further provide the first spectroscopic orbital solutions to the eclipsing, double-lined, O-star binary MT696 (O9.5V + B1:V), the double-lined, early B binary MT720 (B0-1V + B1-2V), and the double-lined, O-star binary MT771 (O7V + O9V). These systems exhibit orbital periods between 1.5 days and 12.3 days, with the majority having P <6 days. The two new binary discoveries and six spectroscopic solutions bring the total number of known massive binaries in the central region of the Cygnus OB2 Association to 20, with all but two having full orbital solutions.

  4. Underground muons from the direction of Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Marshak, M. L.

    1992-01-01

    The flux of underground muons from the direction of the binary Cygnus X-3 was measured by the Soudan 2 proton decay detector. This time-projection calorimeter is located at a depth of 2200 m (water equivalent) in northern Minnesota at latitude 48 deg N, longitude 92 deg W. An analysis was then performed that compared both the total observed flux and the observed flux per transit with the number of events expected in the absence of a source. This expected number of events was determined by combining the detector acceptance as a function of time with detector acceptance as a function of the local spatial coordinates. These functions were evaluated by use of off-source events. The direction of Cygnus X-3 was defined as a 2 deg half-angle cone, centered on the nominal source coordinates. This definition is consistent with the expected appearance of a point source in the Soudan 2 detector after consideration of track reconstruction errors, multiple scattering in the rock, and possible systematic effects. Details of the analysis and the results are presented.

  5. Shell-shocked: the interstellar medium near Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Sell, P. H.; Heinz, S.; Richards, E.; Maccarone, T. J.; Russell, D. M.; Gallo, E.; Fender, R.; Markoff, S.; Nowak, M.

    2015-02-01

    We conduct a detailed case study of the interstellar shell near the high-mass X-ray binary, Cygnus X-1. We present new WIYN optical spectroscopic and Chandra X-ray observations of this region, which we compare with detailed MAPPINGS III shock models, to investigate the outflow powering the shell. Our analysis places improved, physically motivated constraints on the nature of the shock wave and the interstellar medium (ISM) it is plowing through. We find that the shock is travelling at less than a few hundred km s-1 through a low-density ISM (<5 cm-3). We calculate a robust, 3σ upper limit to the total, time-averaged power needed to drive the shock wave and inflate the bubble, <2 × 1038 erg s-1. We then review possible origins of the shock wave. We find that a supernova origin to the shock wave is unlikely and that the black hole jet and/or O-star wind can both be central drivers of the shock wave. We conclude that the source of the Cygnus X-1 shock wave is far from solved.

  6. Multi-wavelength observations of Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Varlotta, Angelo

    2012-07-01

    Cygnus X-3 is a X-ray binary consisting of an accreting compact object orbiting a Wolf-Rayet star with collimated relativistic jets, placing it firmly in the category of microquasars. It has been detected at radio frequencies and up to the high-energy gamma rays (>100 MeV) by the Fermi LAT. Many theoretical models envision very-high-energy (VHE) emission (>100 GeV) when the source manifests relativistic persistent jets or transient ejections. In light of our multi-wavelength studies of Cygnus X-3 in the radio, infra-red, soft x-ray, hard x-ray and gamma-ray (<100 GeV) bands and with the aid of VERITAS, we believe we can cast light on the particular conditions which could trigger VHE emission. We argue this can help us understand the mechanisms that may trigger VHE gamma-ray emission, thus improving our knowledge of particle acceleration and radiative processes in the jets. The implications have far reaching consequences on the understanding of other microquasars and also of active galactic nuclei, which are in many ways similar to microquasars and are prominent VHE gamma-ray sources.

  7. Cygnus Pressurized Cargo Module (PCM) Flight Inertial Load Static Tests

    NASA Astrophysics Data System (ADS)

    Murgia, Giovanni; Mancini, Simone; Palmieri, Paolo; Rutigliano, Luigi

    2012-07-01

    Cygnus PCM Flight Inertial Load Static Test campaign has been performed by Thales Alenia Space - Italy (TAS-I) to achieve the Static Qualification of its Primary Structure. A “Proto-flight Approach” has been followed (as per [1] and [2]), thus the first flight unit, the PCM0, has been tested up to qualification level (qualification/acceptance factor equivalent to 1.2 [1]). The PCM0 has been constrained to a dummy Service Module (the second member of Cygnus Spacecraft), representative in terms of interfaces provisions, and flight load conditions have been reproduced with proper forces that have been applied by means of hydraulic jacks at internal PCM secondary structure interfaces. Test load cases have been defined in order to simulate load paths and relevant stress fields associated to the worst flight load conditions by using the FE model analyses. Tests have been monitored by means of gauges and displacement transducers and results have been utilized to correlate the PCM FEM following [3] requirements.

  8. What is special about Cygnus X-1?. [evidence for a black hole

    NASA Technical Reports Server (NTRS)

    Boldt, E. A.; Holt, S. S.; Rothschild, R. E.; Serlemitsos, P. J.

    1974-01-01

    The X-ray evidence from several experiments is reviewed, with special emphasis on those characteristics which appear to distinguish Cygnus X-1 from other compact X-ray emitting objects. Data are examined within the context of a model in which millisecond bursts are superposed upon shot-noise fluctuations arising from events of durations on the order of a second. Possible spectral-temporal correlations are investigated which provide additional evidence that Cygnus X-1 is very likely a black hole.

  9. Fine structure of the jet from Cygnus A

    NASA Astrophysics Data System (ADS)

    Matveyenko, L. I.; Seleznev, S. V.

    2015-12-01

    The superfine structure of the bipolar outflow from the radio galaxy Cygnus A has been investigated at a wavelength of 2 cm. The surrounding thermal plasma inflows onto the disk and is transferred in a spiral to the center, with the plasma velocity and temperature increasing to relativistic values. The rotating bipolar outflow carries away an excess angular momentum as it is accumulated. The high-velocity central flow is surrounded by parallel chains of components, the tangential directions of the low-velocity flows. Rotation collimates the flow; ring currents, a longitudinal magnetic field, are generated in it. The size of the high-velocity jet exceeds the size of the counterjet by a factor of 3.5 due to the velocity difference: the acceleration of the flow moving along the field and its decelerationwhenmoving in a direction opposite to the magnetic field of the system. The observed features are typical of objects with active nuclei.

  10. The Extreme Spin of the Black Hole Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Gou, Lijun; McClintock, Jeffrey E.; Reid, Mark J.; Orosz, Jerome A.; Steiner, James F.; Narayan, Ramesh; Xiang, Jingen; Remillard, Ronald A.; Arnaud, Keith A.; Davis, Shane W.

    2011-01-01

    Remarkably, an astronomical black hole is completely described by the two numbers that specify its mass and its spin. Knowledge of spin is crucial for understanding how, for example, black holes produce relativistic jets. Recently, it has become possible to measure the spins of black holes by focusing on the very inner region of an accreting disk of hot gas orbiting the black hole. According to General Relativity (GR), this disk is truncated at an inner radius 1 that depends only on the mass and spin of the black hole. We measure the radius of the inner edge of this disk by fitting its continuum X-ray spectrum to a fully relativistic model. Using our measurement of this radius, we deduce that the spin of Cygnus X-1 exceeds 97% of the maximum value allowed by GR.

  11. Subaru spectroscopy and spectral modeling of Cygnus A

    SciTech Connect

    Merlo, Matthew J.; Perlman, Eric S.; Nikutta, Robert; Packham, Christopher; Elitzur, Moshe; Imanishi, Masatoshi; Levenson, N. A.; Radomski, James T.

    2014-06-10

    We present high angular resolution (∼0.''5) MIR spectra of the powerful radio galaxy, Cygnus A (Cyg A), obtained with the Subaru telescope. The overall shape of the spectra agree with previous high angular resolution MIR observations, as well as previous Spitzer spectra. Our spectra, both on and off nucleus, show a deep silicate absorption feature. The absorption feature can be modeled with a blackbody obscured by cold dust or a clumpy torus. The deep silicate feature is best fit by a simple model of a screened blackbody, suggesting that foreground absorption plays a significant, if not dominant, role in shaping the spectrum of Cyg A. This foreground absorption prevents a clear view of the central engine and surrounding torus, making it difficult to quantify the extent the torus attributes to the obscuration of the central engine, but does not eliminate the need for a torus in Cyg A.

  12. An infrared supershell surrounding the Cygnus OB1 association

    NASA Technical Reports Server (NTRS)

    Saken, Jon M.; Shull, J. M.; Garmany, Catharine D.; Nichols-Bohlin, Joy; Fesen, Robert A.

    1992-01-01

    New studies are reported of a large, 2 x 5 deg peanut-shaped cavity in the far-infrared emission seen using IRAS data for the Cygnus X region. A more complete and better defined infrared supershell than reported by Lozinskaya and Repin (1990) is found and connected to the Cyg OB1 association. It is shown that the cavity represents the early stages of a superbubble produced by the winds and possible SNe from 10 to 20 massive stars. The locations and properties of these stars are used to estimate the energy deposition rate and to understand the manner in which supershells form and propagate. In Cyg OB1, spatially distributed subclustering appears to have played an important role in determining the nonspherical morphology of the superbubble.

  13. Catching Up on State Transitions in Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Boeck, Moritz; Hanke, Manfred; Wilms, Joern; Pirner, Stefan; Grinberg, Victoria; Markoff, Sera; Pottschmidt, Katja; Nowak, Michael A.; Pooley, Guy

    2008-01-01

    In 2005 February we observed Cygnus X-1 over a period of 10 days quasi-continuously with the Rossi X-ray Timing Explorer and the Ryle telescope. We present the results of the spectral and timing analysis on a timescale of 90 min and show that the behavior of Cyg X-1 is similar to that found during our years long monitoring campaign. As a highlight we present evidence for a full transition from the hard to the soft state that happened during less than three hours. The observation provided a more complete picture of a state transition than before, especially concerning the evolution of the time lags, due to unique transition coverage and analysis with high time resolution.

  14. Feeding the monster: Wind accretion in Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Miskovicova, Ivica

    2012-07-01

    Stellar wind in HMXBs is highly structured: dense clumps of low temperatures are embedded in highly ionized material. We present analysis of the focused stellar wind in the hard state of Cygnus X-1 from high-resolution Chandra-HETGS observations at four distinct orbital phases: phi~0, ~0.2, ~0.5 and ~0.75. All light curves but the one at phi~0.5 show strong absorption dips that are believed to be caused by the clumps. We compare the spectral properties between dips and persistent flux: while the H-like and He-like absorption lines reveal the highly photoionized wind, the lines of lower ionization stages visible only in the dip spectra constrain the properties of the clumps. Comparison between different orbital phases allows us to study the complex structure and dynamics of the wind.

  15. The exotic mute swan (Cygnus olor) in Chesapeake Bay, USA

    USGS Publications Warehouse

    Perry, M.C.; Perry, M.C.

    2002-01-01

    The exotic mute swan (Cygnus olor) has increased its population size in Chesapeake Bay (Maryland and Virginia) to approximately 4,500 since 1962 when five swans were released in the Bay. The Bay population of mute swans now represents 30% of the total Atlantic Flyway population (12,600) and has had a phenomenal increase of 1,200% from 1986 to 1999. Unlike the tundra swans (Cygnus columbianus) that migrate to the Bay for the winter, the mute swan is a year-long resident, and, therefore, reports of conflicts with nesting native waterbirds and the consumption of submerged aquatic vegetation (SAV) have raised concerns among resource managers. Populations of black skimmers (Rynchops niger) and least terns (Sterna antillarum) nesting on beaches and oyster shell bars have been eliminated by molting mute swans. Although data on the reduction of SAV by nesting mute swans and their offspring during the spring and summer are limited, food habits data show that mute swans rely heavily on SAV during these months. Widgeon grass (Ruppia maritima) constituted 56% and eel grass (Zostera marina) constituted 43% of the gullet food of mute swans. Other SAV and invertebrates (including bryozoans, shrimp, and amphipods) formed a much smaller amount of the food percentage (1%). Invertebrates are believed to have been selected accidently within the vegetation eaten by the swans. Corn (Zea mays) fed to swans by Bay residents during the winter probably supplement limited vegetative food resources in late winter. A program to control swan numbers by the addling of eggs and the killing of adult swans has been a contentious issue with some residents of the Bay area. A management plan is being prepared by a diverse group of citizens appointed by the Governor to advise the Maryland Department of Natural Resources on viable and optimum options to manage mute swans in the Maryland portion of Chesapeake Bay. Hopefully, the implementation of the plan will alleviate the existing conflicts to the

  16. RXTE Observation of Cygnus X-1 Spectral Analysis

    NASA Technical Reports Server (NTRS)

    Dove, J. B.; Wilms, Joern; Nowak, M. A.; Vaughan, B. A.; Begelman, M. C.

    1998-01-01

    We present the results of the analysis of the broad-band spectrum of Cygnus X-1 from 3.0 to 200 keV, using data from a 10 ksec observation by the Rossi X-ray Timing Explorer. Although the spectrum can be well described phenomenologically by an exponentially cut-off power law (photon index Gamma = 1.45+0.01 -0.02 , e-folding energy e(sub f) = 162+9 -8 keV, plus a deviation from a power law that formally can be modeled as a thermal blackbody, with temperature kT(sub BB) = 1.2 +0.0 -0.1 keV), the inclusion of a reflection component does not improve the fit. As a physical description of this system, we apply the accretion disc corona (ADC) models. A slab-geometry ADC model is unable to describe the data. However, a spherical corona, with a total optical depth tau- = 1.6 + or - 0.1 and an average temperature kTc = 87 + or - 5 keV, surrounded by an exterior cold disc, does provide a good description of the data (X red (exp 2) = 1.55). These models deviate from the data bv up to 7% in the 5-10 keV range. However, considering how successfully the spherical corona reproduces the 10-200 keV data, such "photon-starved" coronal geometries seem very promising for explaining the accretion processes of Cygnus X-1.

  17. Study of the Cygnus Star-Forming Field

    NASA Astrophysics Data System (ADS)

    Christopherson, Christopher; Kaltcheva, Nadia

    2016-01-01

    The star-forming complexes in Cygnus extend nearly 30 deg in Galactic longitude and 20 deg in latitude, and most probably include star-formation sites located between 600 and 4000 pc. We combine the catalog by Heiles (2000) with uvbyβ photometric data from the catalog of Paunzen (2015) to collate a sample of O and B-type stars with precise homogeneous distances, color excess and available polarimetry. This allows us to identify star-forming sites at different distances along the line of sight and to investigate their spatial correlation to the interstellar matter. Further, we use this sample to study the orientation of the polarization as revealed by the polarized light of the bright early-type stars and analyze the polarization-extinction correlation for this field. Since dust grains align in the presence of a magnetic field cause the observed polarization at optical wavelengths, the data contain information about the large-scale component of the Galactic magnetic field. In addition, wide-field astrophotography equipment was used to image the Cygnus field in Hydrogen-alpha, Hydrogen-beta and the [OIII] line at 500.7 nm. This allows us to map the overall distribution of ionized material and the interstellar dust and trace large-scale regions where the physical conditions change rapidly due to supernova shock fronts and strong stellar winds. Acknowledgments: This work was supported by NSF grant AST- 1516932 and the Wisconsin Space Grant Consortium, NASA Space Grant College and Fellowship Program, NASA Training Grant #NNX14AP22H.

  18. VizieR Online Data Catalog: Infrared photometry of YSOs in Cygnus-X DR15 (Rivera-Galvez+, 2015)

    NASA Astrophysics Data System (ADS)

    Rivera-Galvez, S.; Roman-Zuniga, C. G.; Jimenez-Bailon, E.; Ybarra, J. E.; Alves, J. F.; Lada, E. A.

    2016-06-01

    Near-infrared images of the Cygnus-X DR15 region were obtained with the OMEGA 2000 camera at the 3.5m telescope of the Calar Alto Observatory, atop Sierra de los Filabres in Almeria, Spain, during the nights of 2010, February 2nd and March 3rd. The data set consists of 900s co-added exposures in the J, H, and K bands (1.209, 1.648, and 2.208μm, respectively). The seeing values-measured directly from the average FWHM of stars in the final reduced mosaics-were 1.17, 1.13, and 0.98" in J, H, and K, respectively. The Spitzer Space Telescope has observed the DR15 cluster with the IRAC and MIPS detectors as part of the Spitzer Cygnus-X Legacy Survey (Hora et al. 2009 ASP Conf. Ser., Reionization to Exoplanets: Spitzer's Growing Legacy ed P. Ogle (San Francisco, CA: ASP) 26; hereafter CXLS). We obtained archival enhanced product mosaics from the Spitzer Heritage Archive as well as a photometric catalog coincident with our region of interest directly from the CXLS Data Release 1 (DR1). The catalog contains calibrated magnitudes for sources detected with IRAC in its four cryogenic mission channels (3.6, 4.5, 5.8, and 8.0μm), as well as in the 24μm channel of MIPS. The DR15 cluster was observed with the Imaging Array of the Chandra Advanced CCD Imaging Spectrometer (ACIS-I) on 2011 January 25 (ObsID12390, P.I. Wright). We made use of the Five College Radio Observatory (FCRAO) 13CO(1-0) molecular radio emission map of the south Cygnus-X region from the study of Schneider et al. (2011A&A...529A...1S). In Tables 2-4 we list YSO sources identified as Class I, Class II, and Class III in our region of study. (3 data files).

  19. RXTE Observation of Cygnus X-1. 1; Spectral Analysis

    NASA Technical Reports Server (NTRS)

    Dove, James B.; Wilms, Joern; Nowak, Michael A.; Vaughan, Brian A.; Begelman, Mitchell C.

    1998-01-01

    We present the results of the analysis of the broad-band spectrum of Cygnus X-1 from 3.0 to 200 keV, using data from a 10 ksec observation by the Rossi X-ray Timing Explorer. The spectrum can be well described phenomenologically by an exponentially cut-off power law with a photon index Gamma = 1.45(+0.01 -0.02) (a value considerably harder 0.02 than typically found), e-folding energy E(sub f) = 162(+9 -8) keV, plus a deviation from a power law that formally can be modeled as a thermal blackbody with temperature kT(sub bb) = 1.2(+0.0 -0.1) keV. Although the 3-30 keV portion of the spectrum can be fit with a reflected power law with Gamma = 1.81 + or - 0.01 and covering fraction f = 0.35 + or - 0.02, the quality of the fit is significantly reduced when the HEXTE data in the 30-100 keV range is included, as there is no observed hardening in the power law within this energy range. As a physical description of this system, we apply the accretion disc corona models of Dove, Wilms & Begelman (1997a) - where the temperature of the corona is determined self-consistently. A spherical corona with a total optical depth pi = 1.6 + or - 0.1 and an average temperature kT(sub c) = 87 + or - 5 keV, surrounded by an exterior cold disc, does provide a good description of the data (X(exp 2 sub red) = 1.55). These models deviate from red the data by up to 7% in the 5 - 10 keV range, and we discuss possible reasons for these discrepancies. However, considering bow successfully the spherical corona reproduces the 10 - 200 keV data, such "pboton-starved" coronal geometries seem very promising for explaining the accretion processes of Cygnus X-1.

  20. Modulated high-energy gamma-ray emission from the microquasar Cygnus X-3.

    PubMed

    Abdo, A A; Ackermann, M; Ajello, M; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Celik, O; Chaty, S; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Corbel, S; Corbet, R; Dermer, C D; de Palma, F; Digel, S W; do Couto e Silva, E; Drell, P S; Dubois, R; Dubus, G; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fusco, P; Gargano, F; Gehrels, N; Germani, S; Giavitto, G; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hill, A B; Hjalmarsdotter, L; Horan, D; Hughes, R E; Jackson, M S; Jóhannesson, G; Johnson, A S; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Koerding, E; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Marchand, L; Marelli, M; Max-Moerbeck, W; Mazziotta, M N; McColl, N; McEnery, J E; Meurer, C; Michelson, P F; Migliari, S; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Ong, R A; Ormes, J F; Paneque, D; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Pooley, G; Porter, T A; Pottschmidt, K; Rainò, S; Rando, R; Ray, P S; Razzano, M; Rea, N; Readhead, A; Reimer, A; Reimer, O; Richards, J L; Rochester, L S; Rodriguez, J; Rodriguez, A Y; Romani, R W; Ryde, F; Sadrozinski, H F-W; Sander, A; Saz Parkinson, P M; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spinelli, P; Starck, J-L; Stevenson, M; Strickman, M S; Suson, D J; Takahashi, H; Tanaka, T; Thayer, J B; Thompson, D J; Tibaldo, L; Tomsick, J A; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Wilms, J; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M

    2009-12-11

    Microquasars are accreting black holes or neutron stars in binary systems with associated relativistic jets. Despite their frequent outburst activity, they have never been unambiguously detected emitting high-energy gamma rays. The Fermi Large Area Telescope (LAT) has detected a variable high-energy source coinciding with the position of the x-ray binary and microquasar Cygnus X-3. Its identification with Cygnus X-3 is secured by the detection of its orbital period in gamma rays, as well as the correlation of the LAT flux with radio emission from the relativistic jets of Cygnus X-3. The gamma-ray emission probably originates from within the binary system, opening new areas in which to study the formation of relativistic jets. PMID:19965378

  1. Modulated High-Energy Gamma-Ray Emission from the Microquasar Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Fermi LAT Collaboration; Abdo, A. A.; Ackermann, M.; Ajello, M.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Çelik, Ö.; Chaty, S.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Corbel, S.; Corbet, R.; Dermer, C. D.; de Palma, F.; Digel, S. W.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Dubus, G.; Dumora, D.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Fortin, P.; Frailis, M.; Fusco, P.; Gargano, F.; Gehrels, N.; Germani, S.; Giavitto, G.; Giebels, B.; Giglietto, N.; Giordano, F.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hill, A. B.; Hjalmarsdotter, L.; Horan, D.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocian, M. L.; Koerding, E.; Kuss, M.; Lande, J.; Latronico, J.; Lemoine-Goumard, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Marchand, L.; Marelli, M.; Max-Moerbeck, W.; Mazziotta, M. N.; McColl, N.; McEnery, J. E.; Meurer, C.; Michelson, P. F.; Migliari, S.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Omodei, N.; Ong, R. A.; Ormes, J. F.; Paneque, D.; Parent, D.; Pelassa, V.; Pepe, M.; Pesce-Rollins, M.; Piron, F.; Pooley, G.; Porter, T. A.; Pottschmidt, K.; Rainò, S.; Rando, R.; Ray, P. S.; Razzano, M.; Rea, N.; Readhead, A.; Reimer, A.; Reimer, O.; Richards, J. L.; Rochester, L. S.; Rodriguez, J.; Rodriguez, A. Y.; Romani, R. W.; Ryde, F.; Sadrozinski, H. F.-W.; Sander, A.; Saz Parkinson, P. M.; Sgrò, C.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spinelli, P.; Starck, J.-L.; Stevenson, M.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tomsick, J. A.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Vilchez, N.; Vitale, V.; Waite, A. P.; Wang, P.; Wilms, J.; Winer, B. L.; Wood, K. W.; Ylinen, T.; Ziegler, M.

    2009-12-01

    Microquasars are accreting black holes or neutron stars in binary systems with associated relativistic jets. Despite their frequent outburst activity, they have never been unambiguously detected emitting high-energy gamma rays. The Fermi Large Area Telescope (LAT) has detected a variable high-energy source coinciding with the position of the x-ray binary and microquasar Cygnus X-3. Its identification with Cygnus X-3 is secured by the detection of its orbital period in gamma rays, as well as the correlation of the LAT flux with radio emission from the relativistic jets of Cygnus X-3. The gamma-ray emission probably originates from within the binary system, opening new areas in which to study the formation of relativistic jets.

  2. How to Determine The Precession of the Inner Accretion Disk in Cygnus X-1

    SciTech Connect

    Torres, D F; Romero, G E; Barcons, X; Lu, Y

    2005-01-05

    We show that changes in the orientation of the inner accretion disk of Cygnus X-1 affect the shape of the broad Fe K{alpha} emission line emitted from this object, in such a way that eV-level spectral resolution observations (such as those that will be carried out by the ASTRO-E2 satellite) can be used to analyze the dynamics of the disk. We here present a new diagnosis tool, supported by numerical simulations, by which short observations of Cygnus X-1, separated in time, can determine whether its accretion disk actually processes, and if so, determine its period and precession angle. Knowing the precession parameters of Cygnus X-1 would result in a clarification of the origin of such precession, distinguishing between tidal and spin-spin coupling. This approach could also be used for similar studies in other microquasar systems.

  3. Application of cosmic-ray shock theories to the Cygnus Loop - An alternative model

    NASA Technical Reports Server (NTRS)

    Boulares, Ahmed; Cox, Donald P.

    1988-01-01

    Steady state cosmic-ray shock models are investigated here in the light of observations of the Cygnus Loop supernova remnant. The predicted downstream temperature is derived for each model. The Cygnus Loop data and the application of the models to them, including wave dissipation, are presented. Heating rate and ionization fraction structures are provided along with an estimate of the cosmic-ray diffusion coefficient. It is found that the model of Voelk, Drury, and McKenzie (1984), in which the plasma waves are generated by the streaming instability of the cosmic rays and are dissipated into the gas, can be made consistent with some observed characteristics of the Cygnus Loop shocks. The model is used to deduce upstream densities and shock velocities and, compared to the usual pure gas shock interpretation, it is found that lower densities and approximately three times higher velocities are required.

  4. Modulated high-energy gamma-ray emission from the microquasar Cygnus X-3.

    PubMed

    Abdo, A A; Ackermann, M; Ajello, M; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Celik, O; Chaty, S; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Corbel, S; Corbet, R; Dermer, C D; de Palma, F; Digel, S W; do Couto e Silva, E; Drell, P S; Dubois, R; Dubus, G; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fusco, P; Gargano, F; Gehrels, N; Germani, S; Giavitto, G; Giebels, B; Giglietto, N; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hill, A B; Hjalmarsdotter, L; Horan, D; Hughes, R E; Jackson, M S; Jóhannesson, G; Johnson, A S; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kawai, N; Kerr, M; Knödlseder, J; Kocian, M L; Koerding, E; Kuss, M; Lande, J; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Marchand, L; Marelli, M; Max-Moerbeck, W; Mazziotta, M N; McColl, N; McEnery, J E; Meurer, C; Michelson, P F; Migliari, S; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Omodei, N; Ong, R A; Ormes, J F; Paneque, D; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Piron, F; Pooley, G; Porter, T A; Pottschmidt, K; Rainò, S; Rando, R; Ray, P S; Razzano, M; Rea, N; Readhead, A; Reimer, A; Reimer, O; Richards, J L; Rochester, L S; Rodriguez, J; Rodriguez, A Y; Romani, R W; Ryde, F; Sadrozinski, H F-W; Sander, A; Saz Parkinson, P M; Sgrò, C; Siskind, E J; Smith, D A; Smith, P D; Spinelli, P; Starck, J-L; Stevenson, M; Strickman, M S; Suson, D J; Takahashi, H; Tanaka, T; Thayer, J B; Thompson, D J; Tibaldo, L; Tomsick, J A; Torres, D F; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, T L; Vasileiou, V; Vilchez, N; Vitale, V; Waite, A P; Wang, P; Wilms, J; Winer, B L; Wood, K S; Ylinen, T; Ziegler, M

    2009-12-11

    Microquasars are accreting black holes or neutron stars in binary systems with associated relativistic jets. Despite their frequent outburst activity, they have never been unambiguously detected emitting high-energy gamma rays. The Fermi Large Area Telescope (LAT) has detected a variable high-energy source coinciding with the position of the x-ray binary and microquasar Cygnus X-3. Its identification with Cygnus X-3 is secured by the detection of its orbital period in gamma rays, as well as the correlation of the LAT flux with radio emission from the relativistic jets of Cygnus X-3. The gamma-ray emission probably originates from within the binary system, opening new areas in which to study the formation of relativistic jets.

  5. Reexamination of the SAS 2 Cygnus X-3 data

    NASA Technical Reports Server (NTRS)

    Fichtel, C. E.; Thompson, D. J.; Lamb, R. C.

    1987-01-01

    Recent observations of Cygnus X-3 have shown marked variability of the radiation on short time scales. In particular, the bursts lasting on the order of 10 minutes, seen in both the infrared and very high energy (greater than 10 to the 11th eV) gamma-ray regions, and the time-variations on many scales at high energies, have stimulated a reanalysis of the March 6 to 13, 1973 SAS 2 high-energy gamma-ray data. Although a clear periodicity in the E greater 35 MeV gamma radiation is observed at the 4.79 hr period seen in X-rays, there is no evidence for major variations of the radiation from one day to the next, and no statistically significant evidence for bursts on the 10-minute time scale seen in the infrared or very high energy ranges. If the excess observed had been predominantly in the form of ten minute bursts even at a rate as high as two/day, a clearly significant set of bursts would have been seen.

  6. Cygnus X-1: A Case for a Magnetic Accretion Disk?

    NASA Technical Reports Server (NTRS)

    Nowak, Michael A.; Vaughan, B. A.; Dove, J.; Wilms, J.

    1996-01-01

    With the advent of Rossi X-ray Timing Explorer (RXTE), which is capable of broad spectral coverage and fast timing, as well as other instruments which are increasingly being used in multi-wavelength campaigns (via both space-based and ground-based observations), we must demand more of our theoretical models. No current model mimics all facets of a system as complex as an x-ray binary. However, a modern theory should qualitatively reproduce - or at the very least not fundamentally disagree with - all of Cygnus X-l's most basic average properties: energy spectrum (viewed within a broader framework of black hole candidate spectral behavior), power spectrum (PSD), and time delays and coherence between variability in different energy bands. Below we discuss each of these basic properties in turn, and we assess the health of one of the currently popular theories: Comptonization of photons from a cold disk. We find that the data pose substantial challenges for this theory, as well as all other in currently discussed models.

  7. Monitoring of heavy metal burden in mute swan (Cygnus olor).

    PubMed

    Grúz, Adrienn; Szemerédy, Géza; Kormos, Éva; Budai, Péter; Majoros, Szilvia; Tompai, Eleonóra; Lehel, József

    2015-10-01

    Concentrations of heavy metals (especially arsenic, cadmium, chromium, copper, mercury and lead) were measured in the contour (body) feathers of mute swans (Cygnus olor) and in its nutrients (fragile stonewort [Chara globularis], clasping leaf pondweed [Potamogeton perfoliatus], Eurasian watermilfoil [Myriophyllum spicatum], fennel pondweed [Potamogeton pectinatus]) to investigate the accumulation of metals during the food chain. The samples (17 feathers, 8 plants) were collected at Keszthely Bay of Lake Balaton, Hungary. Dry ashing procedure was used for preparing of sample and the heavy metal concentrations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Copper (10.24 ± 2.25 mg/kg) and lead (1.11 ± 1.23 mg/kg) were detected the highest level in feathers, generally, the other metals were mostly under the detection limit (0.5 mg/kg). However, the concentrations of the arsenic (3.17 ± 1.87 mg/kg), cadmium (2.41 ± 0.66 mg/kg) and lead (2.42 ± 0.89 mg/kg) in the plants were low but the chromium (198.27 ± 102.21 mg/kg) was detected in high concentration. PMID:26044143

  8. Hard X-ray spectrum of Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Nolan, P. L.; Gruber, D. E.; Knight, F. K.; Matteson, J. L.; Rothschild, R. E.; Marshall, F. E.; Levine, A. M.; Primini, F. A.

    1981-01-01

    Long-term measurements of the hard X-ray spectrum from 3 keV to 8 MeV of the black-hole candidate Cygnus X-1 in its low state are reported. Observations were made from October 26 to November 18, 1977 with the A2 (Cosmic X-ray) and A4 (Hard X-ray and Low-Energy Gamma-Ray) experiments on board HEAO 1 in the spacecraft's scanning mode. The measured spectrum below 200 keV is found to agree well with previous spectra which have been fit by a model of the Compton scattering of optical or UV photons in a very hot plasma of electron temperature 32.4 keV and optical depth 3.9 or 1.6 for spherical or disk geometry, respectively. At energies above 300 keV, however, flux excess is observed which may be accounted for by a distribution of electron temperatures from 15 to about 100 keV.

  9. THE MASS OF THE BLACK HOLE IN CYGNUS X-1

    SciTech Connect

    Orosz, Jerome A.; McClintock, Jeffrey E.; Reid, Mark J.; Narayan, Ramesh; Gou, Lijun; Aufdenberg, Jason P.; Remillard, Ronald A. E-mail: jem@cfa.harvard.edu E-mail: narayan@cfa.harvard.edu E-mail: aufded93@erau.edu

    2011-12-01

    Cygnus X-1 is a binary star system that is comprised of a black hole and a massive giant companion star in a tight orbit. Building on our accurate distance measurement reported in the preceding paper, we first determine the radius of the companion star, thereby constraining the scale of the binary system. To obtain a full dynamical model of the binary, we use an extensive collection of optical photometric and spectroscopic data taken from the literature. By using all of the available observational constraints, we show that the orbit is slightly eccentric (both the radial velocity and photometric data independently confirm this result) and that the companion star rotates roughly 1.4 times its pseudosynchronous value. We find a black hole mass of M = 14.8 {+-} 1.0 M{sub Sun }, a companion mass of M{sub opt} = 19.2 {+-} 1.9 M{sub Sun }, and the angle of inclination of the orbital plane to our line of sight of i = 27.1 {+-} 0.8 deg.

  10. Wavelet analysis of fast photometry on Cygnus X-1 with the AstraLux camera

    SciTech Connect

    Luque-Escamilla, P. L.; Marti, J.; Combi, Jorge A.; Arjonilla, Alvaro Munoz; Sanchez-Sutil, J. R.

    2008-10-08

    We present sub-second fast photometry for the high mass X-ray binary Cygnus X-1. We try to observe variability due to instabilities in the accretion process at optical wavelengths. The observations were carried out using the high speed AstraLux camera at the Calar Alto 2.2 m telescope, Spain, in November 2006 and August 2007. We report that the Cygnus X-1 system light curve sampled every 30 milli-second did not display strong enough evidence of any periodic component related to the source.

  11. Evidence from the Soudan 1 experiment for underground muons associated with Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Ayres, D. S. E.

    1986-01-01

    The Soudan 1 experiment has yielded evidence for an average underground muon flux of approximately 7 x 10 to the minus 11th power/sq cm/s which points back to the X-ray binary Cygnus X-3, and which exhibits the 4.8 h periodicity observed for other radiation from this source. Underground muon events which seem to be associated with Cygnus X-3 also show evidence for longer time variability of the flux. Such underground muons cannot be explained by any conventional models of the propagation and interaction of cosmic rays.

  12. Near-infrared Variability among Young Stellar Objects in the Star Formation Region Cygnus OB7

    NASA Astrophysics Data System (ADS)

    Wolk, Scott J.; Rice, Thomas S.; Aspin, Colin

    2013-08-01

    We present an analysis of near-infrared time-series photometry in J, H, and K bands for about 100 epochs of a 1° × 1° region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. Augmented by data from the Wide-field Infrared Survey Explorer, we identify 96 candidate disk bearing young stellar objects (YSOs) in the region. Of these, 30 are clearly Class I or earlier. Using the Wide-Field Imaging Camera on the United Kingdom Infrared Telescope, we were able to obtain photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J ≈ 17. We study detailed light curves and color trajectories of ~50 of the YSOs in the monitored field. We investigate the variability and periodicity of the YSOs and find the data are consistent with all YSOs being variable in these wavelengths on timescales of a few years. We divide the variability into four observational classes: (1) stars with periodic variability stable over long timescales, (2) variables which exhibit short-lived cyclic behavior, (3) long-duration variables, and (4) stochastic variables. Some YSO variability defies simple classification. We can explain much of the observed variability as being due to dynamic and rotational changes in the disk, including an asymmetric or changing blocking fraction, changes to the inner disk hole size, as well as changes to the accretion rate. Overall, we find that the Class I:Class II ratio of the cluster is consistent with an age of <1 Myr, with at least one individual, wildly varying source ~100, 000 yr old. We have also discovered a Class II eclipsing binary system with a period of 17.87 days.

  13. NEAR-INFRARED VARIABILITY AMONG YOUNG STELLAR OBJECTS IN THE STAR FORMATION REGION CYGNUS OB7

    SciTech Connect

    Wolk, Scott J.; Rice, Thomas S.; Aspin, Colin

    2013-08-20

    We present an analysis of near-infrared time-series photometry in J, H, and K bands for about 100 epochs of a 1 Degree-Sign Multiplication-Sign 1 Degree-Sign region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. Augmented by data from the Wide-field Infrared Survey Explorer, we identify 96 candidate disk bearing young stellar objects (YSOs) in the region. Of these, 30 are clearly Class I or earlier. Using the Wide-Field Imaging Camera on the United Kingdom Infrared Telescope, we were able to obtain photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J Almost-Equal-To 17. We study detailed light curves and color trajectories of {approx}50 of the YSOs in the monitored field. We investigate the variability and periodicity of the YSOs and find the data are consistent with all YSOs being variable in these wavelengths on timescales of a few years. We divide the variability into four observational classes: (1) stars with periodic variability stable over long timescales, (2) variables which exhibit short-lived cyclic behavior, (3) long-duration variables, and (4) stochastic variables. Some YSO variability defies simple classification. We can explain much of the observed variability as being due to dynamic and rotational changes in the disk, including an asymmetric or changing blocking fraction, changes to the inner disk hole size, as well as changes to the accretion rate. Overall, we find that the Class I:Class II ratio of the cluster is consistent with an age of <1 Myr, with at least one individual, wildly varying source {approx}100, 000 yr old. We have also discovered a Class II eclipsing binary system with a period of 17.87 days.

  14. 10 microsecond time resolution studies of Cygnus X-1

    SciTech Connect

    Wen, H.C.

    1997-06-01

    Time variability analyses have been applied to data composed of event times of X-rays emitted from the binary system Cygnus X-1 to search for unique black hole signatures. The X-ray data analyzed was collected at ten microsecond time resolution or better from two instruments, the High Energy Astrophysical Observatory (HEAO) A-1 detector and the Rossi X-ray Timing Explorer (XTE) Proportional Counter Array (PCA). HEAO A-1 and RXTE/PCA collected data from 1977--79 and from 1996 on with energy sensitivity from 1--25 keV and 2--60 keV, respectively. Variability characteristics predicted by various models of an accretion disk around a black hole have been searched for in the data. Drop-offs or quasi-periodic oscillations (QPOs) in the Fourier power spectra are expected from some of these models. The Fourier spectral technique was applied to the HEAO A-1 and RXTE/PCA data with careful consideration given for correcting the Poisson noise floor for instrumental effects. Evidence for a drop-off may be interpreted from the faster fall off in variability at frequencies greater than the observed breaks. Both breaks occur within the range of Keplerian frequencies associated with the inner edge radii of advection-dominated accretion disks predicted for Cyg X-1. The break between 10--20 Hz is also near the sharp rollover predicted by Nowak and Wagoner`s model of accretion disk turbulence. No QPOs were observed in the data for quality factors Q > 9 with a 95% confidence level upper limit for the fractional rms amplitude at 1.2% for a 16 M{sub {circle_dot}} black hole.

  15. RXTE Observation of Cygnus X-1. Report 2; TIming Analysis

    NASA Technical Reports Server (NTRS)

    Nowak, Michael A.; Vaughan, Brian A.; Wilms, Joern; Dove, James B.; Begelman, Mitchell C.

    1998-01-01

    We present timing analysis for a Rossi X-ray Timing Explorer (RXTE) observation of Cygnus X-1 in its hard/low state. This was the first RXTE observation of Cyg X-1 taken after it transited back to this state from its soft/high state. RXTE's large effective area, superior timing capabilities, and ability to obtain long, uninterrupted observations have allowed us to obtain measurements of the power spectral density (PSD), coherence function, and Fourier time lags to a decade lower in frequency and half a decade higher in frequency than typically was achieved with previous instruments. Notable aspects of our observations include a weak 0.005 Hz feature in the PSD coincident with a coherence recovery; a 'hardening' of the high-frequency PSD with increasing energy; a broad frequency range measurement of the coherence function, revealing rollovers from unity coherence at both low and high frequency; and an accurate determination of the Fourier time lags over two and a half decades in frequency. As has been noted in previous similar observations, the time delay is approximately proportional to f(exp -0.7), and at a fixed Fourier frequency the time delay of the hard X-rays compared to the softest energy channel tends to increase logarithmically with energy. Curiously, the 0.01-0.2 Hz coherence between the highest and lowest energy bands is actually slightly greater than the coherence between the second highest and lowest energy bands. We carefully describe all of the analysis techniques used in this paper, and we make comparisons of the data to general theoretical expectations. In a companion paper, we make specific comparisons to a Compton corona model that we have successfully used to describe the energy spectral data from this observation.

  16. The massive star population of Cygnus OB2

    NASA Astrophysics Data System (ADS)

    Wright, Nicholas J.; Drew, Janet E.; Mohr-Smith, Michael

    2015-05-01

    We have compiled a significantly updated and comprehensive census of massive stars in the nearby Cygnus OB2 association by gathering and homogenizing data from across the literature. The census contains 169 primary OB stars, including 52 O-type stars and 3 Wolf-Rayet stars. Spectral types and photometry are used to place the stars in a Hertzsprung-Russell diagram, which is compared to both non-rotating and rotating stellar evolution models, from which stellar masses and ages are calculated. The star formation history and mass function of the association are assessed, and both are found to be heavily influenced by the evolution of the most massive stars to their end states. We find that the mass function of the most massive stars is consistent with a `universal' power-law slope of Γ = 1.3. The age distribution inferred from stellar evolutionary models with rotation and the mass function suggest the majority of star formation occurred more or less continuously between 1 and 7 Myr ago, in agreement with studies of low- and intermediate-mass stars in the association. We identify a nearby young pulsar and runaway O-type star that may have originated in Cyg OB2 and suggest that the association has already seen its first supernova. Finally we use the census and mass function to calculate the total mass of the association of 16 500^{+3800}_{-2800} M⊙, at the low end, but consistent with, previous estimates of the total mass of Cyg OB2. Despite this Cyg OB2 is still one of the most massive groups of young stars known in our Galaxy making it a prime target for studies of star formation on the largest scales.

  17. A Far-Ultraviolet Study of the Cygnus Loop Using the VOYAGER Ultraviolet Spectrometers

    NASA Technical Reports Server (NTRS)

    Vancura, Olaf; Blair, William P.; Long, Knox S.; Raymond, John C.; Holberg, J. B.

    1993-01-01

    We have used the Voyager 1 and 2 Ultraviolet Spectrometers to study the far-ultraviolet emissions from different types of shock waves in the Cygnus Loop. In the southeast and northern parts of the supernova remnant (SNR), we have measured the O(VI) lambda1035 surface brightness from the main blast wave. This value is several times below the average and more than one order of magnitude below the peak O(VI) brightness in the SNR as measured with Voyager. A simple blast wave model appears able to reproduce the observations in the southeast and the northern parts of the Cygnus Loop but can only account for 10%-15% of the total O(VI) emission from the Cygnus Loop. The brightest O(VI) and C(III) lambda977 emission is found coincident with optical filamentation and X-ray enhancements in the northeast. We interpret the observations in the northeast in terms of nonradiative and incomplete shocks whose surface area rises in the optical filamentary regions. We conclude that the bulk of the O(VI) emission from the Cygnus Loop arises from optically bright clouds within which intermediate-velocity (200 + 50 km/s) nonradiative and incomplete shocks are widespread.

  18. Long-term studies with the Ariel 5 ASM. 2: The strong Cygnus sources

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Kaluzienski, L. J.; Boldt, E. A.; Serlemitsos, P. J.

    1979-01-01

    The three bright 3-6 keV X-ray sources in Cygnus are examined for regular temporal variability with a 1300-day record from the Ariel 5 All Sky Monitor. The only periods consistently observed are 5.6 days for Cyg X-1, 11.23 days for Cyg X-2, and 4.8 hours for Cyg X-3.

  19. RXTE/ASM Observations Of SS 433 And Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Hoffman, Lisa; Mason, P. A.

    2010-01-01

    We present a dynamic period search analysis of the X-ray binaries SS 433 and Cygnus X-2 using data from the Rossi X-Ray Timing Explorer All Sky Monitor (RXTE/ASM) spanning over 13 years. We report the detection of a period in SS 433 near 162 days. This may be the first detection of the disk precession period in X-rays. We detect an 81.8 day period in the object Cygnus X-2. The RXTE/ASM light curve is inconsistent with the 77.7 day X-ray period of Wijnands et al. (1996), which was based on a small subset of the RXTE/ASM data combined with data from VELA 5B, and Ariel 5 All-Sky Monitors. Since Cygnus X-2 displays periodic behavior that seems to come and go, producing different best-fit periods on time scales of a few years; we suggest that Cygnus X-2 exhibits quasi-periodic oscillations of about 80 days. This research is supported by a grant from the New Mexico Space Grant Consortium.

  20. JOINT SUZAKU AND XMM-NEWTON SPECTRAL ANALYSIS OF THE SOUTHWEST CYGNUS LOOP

    SciTech Connect

    Leahy, Denis; Hassan, Mohammed

    2013-02-10

    We carry out a joint spectral analysis of the Cygnus Loop using data from all six detectors combined from Suzaku and XMM-Newton. This had not been done before, but if a spectral model is physically realistic, it is required that it be consistent with data from different instruments. Thus, our results are an important verification of spectral models for the Cygnus Loop. One of the prominent features of the Cygnus Loop is the bright 'V' region near the southwest rim. We choose this region, in part, because it has been observed by both Suzaku and XMM-Newton. We divide the field of view into 12 box-shaped regions, such that each contains 9000-13,000 photons in the Suzaku-XIS1 camera. A non-equilibrium ionization model with variable abundances (VNEI) or a two-component VNEI model is found to fit the observations. Resulting electron temperatures and ionization timescales are inversely related, consistent with an origin in density variations by a factor of {approx}3. Element abundances and temperature are strongly correlated, which can be explained by mixing in the outer hydrogen-rich envelope of ejecta: Heavy-element-rich regions have higher velocity to reach this far out from the center of the Cygnus Loop, resulting in higher shock temperature for more element-rich regions.

  1. No Radio Flaring Detected from Cygnus X-3 at 3 GHz by Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Williams, P. K. G.; Bower, G. C.; Tomsick, J. A.; Bodaghee, A.; Corbet, R. H. D.

    2011-01-01

    Following the announcement of a 98 GHz flare from the microquasar Cygnus X-3 (ATel #3130), we observed it with the Allen Telescope Array (Welch et al., 2009 Proc. IEEE 97 1438 for 2.5 hours beginning at 2011 January 28.848 UT (MJD 55589.848), about 4.0 hours after the 98 GHz observations concluded.

  2. Cygnus OB2 DANCe: A high-precision proper motion study of the Cygnus OB2 association

    NASA Astrophysics Data System (ADS)

    Wright, Nicholas J.; Bouy, Herve; Drew, Janet E.; Sarro, Luis Manuel; Bertin, Emmanuel; Cuillandre, Jean-Charles; Barrado, David

    2016-08-01

    We present a high-precision proper motion study of 873 X-ray and spectroscopically selected stars in the massive OB association Cygnus OB2 as part of the DANCe project. These were calculated from images spanning a 15 yr baseline and have typical precisions <1 mas yr-1. We calculate the velocity dispersion in the two axes to be σ _α (c) = 13.0^{+0.8}_{-0.7} and σ _δ (c) = 9.1^{+0.5}_{-0.5} km s-1, using a two-component, two-dimensional model that takes into account the uncertainties on the measurements. This gives a three-dimensional velocity dispersion of σ3D = 17.8 ± 0.6 km s-1 implying a virial mass significantly larger than the observed stellar mass, confirming that the association is gravitationally unbound. The association appears to be dynamically unevolved, as evidenced by considerable kinematic substructure, non-isotropic velocity dispersions and a lack of energy equipartition. The proper motions show no evidence for a global expansion pattern, with approximately the same amount of kinetic energy in expansion as there is in contraction, which argues against the association being an expanded star cluster disrupted by process such as residual gas expulsion or tidal heating. The kinematic substructures, which appear to be close to virial equilibrium and have typical masses of 40-400 M⊙, also do not appear to have been affected by the expulsion of the residual gas. We conclude that Cyg OB2 was most likely born highly substructured and globally unbound, with the individual subgroups born in (or close to) virial equilibrium, and that the OB association has not experienced significant dynamical evolution since then.

  3. Diet and nutrition of western rock lobsters, Panulirus cygnus, in shallow coastal waters: the role of habitat

    EPA Science Inventory

    Generalist consumers often have diets that vary considerably over time and space, which reflects changes in resource availability. Predicting diets of consumers can therefore be difficult. The western rock lobster, Panulirus cygnus, is an omnivorous generalist consumer that uses ...

  4. The dust scattering halo of Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Corrales, L. R.; Paerels, F.

    2015-10-01

    Dust grains scatter X-ray light through small angles, producing a diffuse halo image around bright X-ray point sources situated behind a large amount of interstellar material. We present analytic solutions to the integral for the dust scattering intensity, which allow for a Bayesian analysis of the scattering halo around Cygnus X-3. Fitting the optically thin 4-6 keV halo surface brightness profile yields the dust grain size and spatial distribution. We assume a power-law distribution of grain sizes (n ∝ a-p) and fit for p, the grain radius cut-off amax, and dust mass column. We find that a p ≈ 3.5 dust grain size distribution with amax ≈ 0.2 μm fits the halo profile relatively well, whether the dust is distributed uniformly along the line of sight or in clumps. We find that a model consisting of two dust screens, representative of foreground spiral arms, requires the foreground Perseus arm to contain 80 per cent of the total dust mass. The remaining 20 per cent of the dust, which may be associated with the outer spiral arm of the Milky Way, is located within 1 kpc of Cyg X-3. Regardless of which model was used, we found τ_sca ˜ 2 E_keV^{-2}. We examine the energy resolved haloes of Cyg X-3 from 1 to 6 keV and find that there is a sharp drop in scattering halo intensity when E < 2-3 keV, which cannot be explained with multiple scattering effects. We hypothesize that this may be caused by large dust grains or material with unique dielectric properties, causing the scattering cross-section to depart from the Rayleigh-Gans approximation that is used most often in X-ray scattering studies. The foreground Cyg OB2 association, which contains several evolved stars with large extinction values, is a likely culprit for grains of unique size or composition.

  5. Infrared photometry and polarimetry of Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Jones, Terry Jay; Gehrz, Robert D.; Kobulnicky, Henry A.; Molnar, Lawrence A.; Howard, Eric M.

    1994-01-01

    We present photometry and linear polarimetry of Cygnus X-3 at K (2.2 micrometers) obtained over a 5 yr period. Photometry and polarimetry at J, H, and K of nearby field stars is also presented. From an analysis of these data we find: (1) Using the x-ray ephemeris of Kitamoto et al. (ApJ, 384, 263 (1992), including the first and second derivatives of the period, the leading edge of the decline to minimum in the quiescent K light curve has not changed in phase since 1974. The duration of the minimum in the light curve has changed significantly between different epochs, becoming much broader in 1993 than it was previously. (2) In addition to an interstellar polarization component, it is likely Cyg X-3 has an intrinsic polarization component that is variable. The variations in the polarization do not show any diagnostic pattern with orbital phase. A crude analysis of the polarization suggests the intrinsic polarization of Cyg X-3 has a mean position angle of approximately 12 deg, nearly the same as the direction of the expanding radio lobes. This is consistent with circumstellar electrons scattering in an equatorial disk that is perpendicular to the lobe axis. (3) The mean position angle for the interstellar polarization in the direction of Cyg X-3 is 150 deg. This is nearly perpendicular to the axis of interstellar radio scattering seen in the extended (Very Long Baseline Inteferometry (VLBI) images. Since the position angle of interstellar polarization is the same as the projected magnetic field direction, this suggests the interstellar (not circumstellar) scattering must be taking place perpendicular to the interstellar magnetic field lines. (4) Cyg X-3 was observed at K during a flare on 1992 September 30 with a temporal resolution of 6 s. The flaring had rise and fall times of approximately 50 s with peak intensities up to 80 mJy. The flux between individual flare events never dropped to quiescent levels for the duration of our observations (approximately 2000 s).

  6. Photometric Observations of 6000 Stars in the Cygnus Field

    NASA Technical Reports Server (NTRS)

    Borucki, W.; Caldwell, D.; Koch, D.; Jenkins, J.; Ninkov, Z.

    1999-01-01

    A small photometer to detect transits by extrasolar planets has been assembled and is being tested at Lick Observatory on Mt. Hamilton, California. The Vulcan photometer is constructed from a 30 cm focal length, F/2.5 AeroEktar reconnaissance lens and Photometrics PXL16800 CCD camera. A spectral filter is used to confine the pass band from 480 to 763 mn. It simultaneously monitors 6000 stars brighter than 12th magnitude within a single star field in the galactic plane. When the data are folded and phased to discover low amplitude transits, the relative precision of one-hour samples is about 1 part per thousand (10 x l0(exp -3)) for many of the brighter stars. This precision is sufficient to find jovian-size planets orbiting solar-like stars, which have signal amplitudes from 5 to 30 x l0(exp -3) depending on the inflation of the planet and the size of the star. Based on the frequency of giant inner-planets discovered by Doppler-velocity method, one or two planets should be detectable in a rich star field. The goal of the observations is to obtain the sizes of giant extrasolar planets in short-period orbits and to combine these with masses determined from Doppler velocity measurements to determine the densities of these planets. A further goal is to compare the measured planetary diameters with those predicted from theoretical models. From August 10 through September 30 of 1998, a forty nine square degree field in the Cygnus constellation centered at RA and DEC of 19 hr 47 min, +36 deg 55 min was observed. Useful data were obtained on twenty-nine nights. Nearly fifty stars showed some evidence of transits with periods between 0.3 and 8 days. Most had amplitudes too large to be associated with planetary transits. However, several stars showed low amplitude transits. The data for several transits of each of these two stars have been folded and been folded into 30 minute periods. Only Cygl433 shows any evidence of a flattened bottom that is expected when a small object

  7. Short report: Antibody prevalence of select arboviruses in mute swans (Cygnus olor) in the Great Lakes region and Atlantic coast of the United States.

    PubMed

    Pedersen, Kerri; Marks, David R; Arsnoe, Dustin M; Bevins, Sarah N; Wang, Eryu; Weaver, Scott C; Mickley, Randall M; DeLiberto, Thomas J

    2014-12-01

    Mute swans (Cygnus olor) are an invasive species in the United States. The dramatic increase in their populations in localized areas has led to various problems, among them competition with native species and attacks on humans by aggressive swans. However, very little is known about the ability of these swans to transmit pathogens to humans, domestic birds, or wildlife or participate in enzootic maintenance. To learn more about select pathogens that mute swans may harbor, a survey was conducted from April of 2011 to August of 2012 in the Great Lakes region and localized areas of the Atlantic coast, which revealed serologic evidence of arbovirus exposure in mute swans. Of 497 mute swans tested, antibodies were detected for eastern equine encephalitis (4.8%), St. Louis encephalitis (1.4%), West Nile (1.2%), and Turlock (0.6%) viruses. Samples were also tested for evidence of antibodies to La Crosse virus, but none were positive.

  8. Short report: Antibody prevalence of select arboviruses in mute swans (Cygnus olor) in the Great Lakes region and Atlantic coast of the United States.

    PubMed

    Pedersen, Kerri; Marks, David R; Arsnoe, Dustin M; Bevins, Sarah N; Wang, Eryu; Weaver, Scott C; Mickley, Randall M; DeLiberto, Thomas J

    2014-12-01

    Mute swans (Cygnus olor) are an invasive species in the United States. The dramatic increase in their populations in localized areas has led to various problems, among them competition with native species and attacks on humans by aggressive swans. However, very little is known about the ability of these swans to transmit pathogens to humans, domestic birds, or wildlife or participate in enzootic maintenance. To learn more about select pathogens that mute swans may harbor, a survey was conducted from April of 2011 to August of 2012 in the Great Lakes region and localized areas of the Atlantic coast, which revealed serologic evidence of arbovirus exposure in mute swans. Of 497 mute swans tested, antibodies were detected for eastern equine encephalitis (4.8%), St. Louis encephalitis (1.4%), West Nile (1.2%), and Turlock (0.6%) viruses. Samples were also tested for evidence of antibodies to La Crosse virus, but none were positive. PMID:25266351

  9. NEAR-INFRARED VARIABILITY IN YOUNG STARS IN CYGNUS OB7

    SciTech Connect

    Rice, Thomas S.; Wolk, Scott J.; Aspin, Colin

    2012-08-10

    We present the first results from a 124 night J, H, K near-infrared monitoring campaign of the dark cloud L 1003 in Cygnus OB7, an active star-forming region. Using three seasons of UKIRT observations spanning 1.5 years, we obtained high-quality photometry on 9200 stars down to J = 17 mag, with photometric uncertainty better than 0.04 mag. On the basis of near-infrared excesses from disks, we identify 30 pre-main-sequence stars, including 24 which are newly discovered. We analyze those stars and find that the NIR excesses are significantly variable. All 9200 stars were monitored for photometric variability; among the field star population, {approx}160 exhibited near-infrared variability (1.7% of the sample). Of the 30 young stellar objects (YSOs), 28 of them (93%) are variable at a significant level. Of the 30 YSOs, twenty-five have near-infrared excess consistent with simple disk-plus-star classical T Tauri models. Nine of these (36%) drift in color space over the course of these observations and/or since Two Micron All Sky Survey observations such that they cross the boundary defining the NIR excess criteria; effectively, they have a transient near-infrared excess. Thus, time-series JHK observations can be used to obtain a more complete sample of disk-bearing stars than single-epoch JHK observations. About half of the YSOs have color-space variations parallel to either the classical T Tauri star locus or a hybrid track which includes the dust reddening trajectory. This indicates that the NIR variability in YSOs that possess accretion disks arises from a combination of variable extinction and changes in the inner accretion disk: either in accretion rate, central hole size, and/or the inclination of the inner disk. While some variability may be due to stellar rotation, the level of variability on the individual stars can exceed a magnitude. This is a strong empirical suggestion that protoplanetary disks are quite dynamic and exhibit more complex activity on short

  10. Studying the Warm Layer and the Hardening Factor in Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Yao, Yangsen; Zhang, Shuangnan; Zhang, Xiaoling; Feng, Yuxin

    2002-01-01

    As the first dynamically determined black hole X-ray binary system, Cygnus X-1 has been studied extensively. However, its broadband spectrum observed with BeppoSax is still not well understood. Besides the soft excess described by the multi-color disk model (MCD), the power-law hard component and a broad excess feature above 10 keV (a disk reflection component), there is also an additional soft component around 1 keV, whose origin is not known currently. Here we propose that the additional soft component is due to the thermal Comptonization between the soft disk photons and a warm plasma cloud just above the disk, i.e., a warm layer. We use the Monte-Carlo technique to simulate this Compton scattering process and build a table model based on our simulation results. With this table model, we study the disk structure and estimate the hardening factor to the MCD component in Cygnus X-1.

  11. Search for TeV Gamma Rays from Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Cui, Wei; VERITAS Collaboration

    2013-06-01

    We report results from a systematic search for gamma-ray emission from Cygnus X-3 at TeV energies with VERITAS. The source is an enigmatic X-ray binary that has defied classification. Its short orbital period is typical of low-mass X-ray binaries, yet signatures of a Wolf-Rayet star are evident. Powerful jets seen are indicative of microquasar, but arguments for the existence of a neutron star are also compelling. Recently, Cygnus X-3 was detected at GeV gamma-ray energies with AGILE and Fermi LAT. There is strong evidence that GeV gamma-ray production is correlated with the radio/X-ray properties of the source. To this end, we have also carried out more focused searches for TeV gamma rays in the radio/X-ray states of interest.

  12. SAS-3 observations of an X-ray flare from Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Canizares, C. R.; Bradt, H.; Buff, J.; Laufer, B.

    1976-01-01

    Preliminary results are presented for the SAS-3 observation of an X-ray flare from Cygnus X-1. The 1.5 to 6 keV intensity rose by a factor of four and exhibited variability on several time scales from seconds to hours. The 6 to 15 keV intensity showed less activity. The event is similar to that observed by ANS and Ariel 5, but lasted less than two weeks.

  13. Galactic transients with AGILE: the case of Eta Carinae and Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Sabatini, Sabina; Tavani, M.; Caraveo, P.; Barbiellini, G.; Costa, E.; Feroci, M.; Argan, A.; Bulgarelli, A.; Cattaneo, P. W.; Chen, A. W.; D'Ammando, F.; de Paris, G.; Del Monte, E.; Di Cocco, G.; Donnarumma, I.; Evangelista, Y.; Ferrari, A.; Fiorini, M.; Fuschino, F.; Galli, M.; Gianotti, F.; Giuliani, A.; Giusti, M.; Labanti, C.; Lazzarotto, F.; Lipari, P.; Longo, F.; Marisaldi, M.; Mereghetti, S.; Morelli, E.; Moretti, E.; Morselli, A.; Pacciani, L.; Pellizzoni, A.; Perotti, F.; Piano, G.; Picozza, P.; Pilia, M.; Pucella, G.; Prest, M.; Rapisarda, M.; Rappoldi, A.; Rubini, A.; Scalise, E.; Soffitta, P.; Striani, E.; Trifoglio, M.; Trois, A.; Vallazza, E.; Vercellone, S.; Zambra, A.; Zanello, D.; Pittori, C.; Verrecchia, F.; Vittorini, V.; Santolamazza, P.; Giommi, P.; Colafrancesco, S.; Antonelli, L. A.; Salotti, L.

    During its first 2.5 years of operation, the gamma-ray AGILE satellite accumulated an extensive dataset for the Galactic plane and carried out a specific search for emission from binary systems. Powerful colliding winds or relativistic jets in these systems can cause strong shocks in which both electrons and protons can be efficiently accelerated producing non-thermal emission. We developed specific tools of analysis for the search of transient gamma-ray sources in the data and several candidates were detected. Their variability and possible association were studied. In this talk we will mainly focus on the results of extensive observations of the Carina Re-gion and the Cygnus Region during the time period 2007 July -mid 2010. Both regions are extremely complex, hosting massive star formation, giant molecular clouds, HII regions and massive star star clusters. We present a detailed analysis of the gamma-ray data for the regions. In particular, we detect a gamma ray source (1AGL J1043-5931) consistent with the position of the colliding wind binary system Eta Carinae, and report a remarkable 2-days gamma-ray flaring episode from this source, providing the long sought first detection above 100 MeV of a colliding wind binary. Several steady and transient sources have been detected by AGILE in the Cygnus Region. Here we present the results of an extensive search for transient gamma-ray emission from the black hole binary system Cygnus X-1, during the period 2007 July -2009 October. We report an episode of significant transient gamma-ray emission detected on 2009, October 16 in a position compatible with Cygnus X-1.

  14. Relevance of jet emitting disc physics to microquasars: application to Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Petrucci, P. O.; Ferreira, J.; Henri, G.; Malzac, J.; Foellmi, C.

    2010-11-01

    Context. Interpretation of the X-ray spectra of X-ray binaries during their hard states requires a hot, optically thin medium. There are several accretion disc models that account for this aspect. However, none is designed to simultaneously explain powerful jets detected during these states. Aims: A new quasi-Keplerian hot accretion disc solution, a jet emitting disc (JED hereafter), which is part of a global disc-jet MHD structure producing stationary super-alfvénic ejection, is investigated here. Its radiative and energetic properties are then compared to the observational constraints found in Cygnus X-1. Methods: We solve the disc energy equation by balancing the local heating term with advection and cooling by synchrotron, bremsstrahlung, and Comptonization processes. The heating term, disc density, accretion velocity, and magnetic field amplitude were taken from published self-similar models of accretion-ejection structures. Both optically thin and thick regimes are considered in a one-temperature, gas-supported disc. Results: Three branches of solutions are found to be possible at a given radius, but we only investigate the hot, optically thin and geometrically slim solutions. These solutions give simultaneously and consistently the radiative and energetics properties of the disc-jet system. They are able to reproduce the global accretion-ejection properties of Cygnus X-1 very well, namely its X-ray spectral emission, jet power, and jet velocity. About half of the released accretion power is used to produce two mildly relativistic (v/c≃ 0.5) jets, and for a luminosity of about 1% of the Eddington luminosity, the JED temperature and optical depth are close to what is observed in the hard state of Cygnus X-1. Conclusions: The accretion and ejection properties of JEDs agree with the observations of the prototypical black hole binary Cygnus X-1. The JED solutions are likely to be relevant to the whole class of microquasars.

  15. Fussy Feeders: Phyllosoma Larvae of the Western Rocklobster (Panulirus cygnus) Demonstrate Prey Preference

    PubMed Central

    Saunders, Megan I.; Thompson, Peter A.; Jeffs, Andrew G.; Säwström, Christin; Sachlikidis, Nikolas; Beckley, Lynnath E.; Waite, Anya M.

    2012-01-01

    The Western Rocklobster (Panulirus cygnus) is the most valuable single species fishery in Australia and the largest single country spiny lobster fishery in the world. In recent years a well-known relationship between oceanographic conditions and lobster recruitment has become uncoupled, with significantly lower recruitment than expected, generating interest in the factors influencing survival and development of the planktonic larval stages. The nutritional requirements and wild prey of the planktotrophic larval stage (phyllosoma) of P. cygnus were previously unknown, hampering both management and aquaculture efforts for this species. Ship-board feeding trials of wild-caught mid-late stage P. cygnus phyllosoma in the eastern Indian Ocean, off the coast of Western Australia, were conducted in July 2010 and August-September 2011. In a series of experiments, phyllosoma were fed single and mixed species diets of relatively abundant potential prey items (chaetognaths, salps, and krill). Chaetognaths were consumed in 2–8 times higher numbers than the other prey, and the rate of consumption of chaetognaths increased with increasing concentration of prey. The highly variable lipid content of the phyllosoma, and the fatty acid profiles of the phyllosoma and chaetognaths, indicated they were from an oligotrophic oceanic food chain where food resources for macrozooplankton were likely to be constrained. Phyllosoma fed chaetognaths over 6 days showed significant changes in some fatty acids and tended to accumulate lipid, indicating an improvement in overall nutritional condition. The discovery of a preferred prey for P. cygnus will provide a basis for future oceanographic, management and aquaculture research for this economically and ecologically valuable species. PMID:22586479

  16. Support for joint infrared and Copernicus X-Ray observations of Cygnus X-3

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Simultaneous X-ray and infrared measurements were carried out of the flares from Cygnus X-3 from the Copernicus spacecraft observatory. The detectors, InSb, were arranged so that 1.65 and 2.2 micrometer broadbend photometry was performed through a common diaphragm. The measurements were used to determine the energy distribution during a flare and thus learn about the infrared spectrum and its changes during the flare.

  17. Far-ultraviolet mapping of the Cygnus Loop with the Voyager 2 Ultraviolet Spectrometer

    SciTech Connect

    Blair, W.P.; Long, K.S.; Vancura, O.; Holberg, J.B. Arizona, University, Tucson )

    1991-06-01

    FUV maps of the Cygnus Loop made using spectroscopic data from the Voyager 2 Ultraviolet Spectrometer are presented. Emission line features at about 980 and about 1035 A dominate the 500-1700 A spectra of the Cygnus Loop as observed with Voyager. Maps were generated in the light of these two features. The 980 and 1035 A maps are compared with X-ray and optical images of the Cygnus Loop that have been sampled in the same manner. From this comparison it is clear that the 980 A feature arises mainly from regions of bright optical emission, whereas the 1035 A emission more closely resembles the X-ray emission. This general impression can be confirmed by inspection of the spectra as a function of position. Spectra extracted from positions corresponding to the primary shock front show the 1035 A feature to be relatively strong, while the 980 A feature is brighter when substantial optical emission is present within the aperture. 42 refs.

  18. Spectral energy distribution, radio maps and polarization of Cygnus X-1: a lepto-hadronic model

    NASA Astrophysics Data System (ADS)

    Vila, G. S.; Pepe, C.; Romero, G. E.

    2016-08-01

    The microquasar Cygnus X-1 is one of the most studied astrophysical sources. Several radiative models for the non-thermal broadband emission of Cygnus X-1 are available. For the jet emission in particular, only leptonic models have been considered despite the observational evidence of the presence of hadrons in the jets of other microquasars. In this work, we present an inhomogeneous, lepto-hadronic jet model for the non-thermal broadband emission of Cygnus X-1. We calculate the contribution to the spectrum of both relativistic electrons and protons, taking into account their interaction with the magnetic field, matter and photon fields internal and external to the jet. We obtain best-fit models for the spectrum that reproduce the observations from radio to gamma rays, including the MeV tail whose origin is still disputed. We also produce synthetic radio maps of the jet and compare them to actual interferometric observations of the source. Finally, we present preliminary results for the degree of polarization of the jet radiation in the MeV band.

  19. Discovery of a Pulsar Wind Nebula Candidate in the Cygnus Loop

    NASA Technical Reports Server (NTRS)

    Katsuda, Satoru; Tsunemi, Hiroshi; Mori, Koji; Uchida, Hiroyuki; Petre, Robert; Yamada, Shin'ya; Tamagawa, Toru

    2012-01-01

    We report on a discovery of a diffuse nebula containing a point-like source in the southern blowout region of the Cygnus Loop supernova remnant, based on Suzaku and XMM-Newton observations. The X-ray spectra from the nebula and the point-like source are well represented by an absorbed power-law model with photon indices of 2.2+/-0.1 and 1.6+/-0.2, respectively. The photon indices as well as the flux ratio of F(sub nebula)/F(sub point-like) approx. 4 lead us to propose that the system is a pulsar wind nebula, although pulsations have not yet been detected. If we attribute its origin to the Cygnus Loop supernova, then the 0.5-8 keV luminosity of the nebula is computed to be 2.1x10(exp 31)(d/540pc)(exp 2)ergss/2, where d is the distance to the Loop. This implies a spin-down loss-energy E approx. 2.6x10(exp 35)(d/540pc)(exp 2)ergs/s. The location of the neutron star candidate, approx.2deg away from the geometric center of the Loop, implies a high transverse velocity of approx.1850(theta/2deg)(d/540pc)(t/10kyr)/k/s assuming the currently accepted age of the Cygnus Loop.

  20. CARBON, HELIUM, AND PROTON KINETIC TEMPERATURES IN A CYGNUS LOOP SHOCK WAVE

    SciTech Connect

    Raymond, John C.; Edgar, Richard J.; Ghavamian, Parviz; Blair, William P.

    2015-06-01

    Observations of SN 1006 have shown that ions and electrons in the plasma behind fast supernova remnant shock waves are far from equilibrium, with the electron temperature much lower than the proton temperature and ion temperatures approximately proportional to ion mass. In the ∼360 km s{sup −1}shock waves of the Cygnus Loop, on the other hand, electron and ion temperatures are roughly equal, and there is evidence that the oxygen kinetic temperature is not far from the proton temperature. In this paper, we report observations of the He ii λ1640 line and the C iv λ1550 doublet in a 360 km s{sup −1}shock in the Cygnus Loop. While the best-fit kinetic temperatures are somewhat higher than the proton temperature, the temperatures of He and C are consistent with the proton temperature and the upper limits are 0.5 and 0.3 times the mass-proportional temperatures, implying efficient thermal equilibration in this collisionless shock. The equilibration of helium and hydrogen affects the conversion between proton temperatures determined from Hα line profiles and shock speeds, and the efficient equilibration found here reduces the shock speed estimates and the distance estimate to the Cygnus Loop of Medina et al. to about 800 pc.

  1. Estimate from Gulmarg of PeV photon flux from Cygnus X-3 and its relevance

    NASA Astrophysics Data System (ADS)

    Bhat, C. L.; Sapru, M. L.; Razdan, H.

    1986-07-01

    Atmospheric pulses recorded at Gulmarg, India between January 1976 and December 1977 using wide-angle photomultipliers indicate a phase-dependent component exhibiting the Cygnus X-3 modulation period of 4.8 hr, and an amplitude, determined by the number of excess events in the phase peak relative to the total phase-independent events, of 1.8 + or - 0.4 percent (corresponding to a detected average flux of 1.6 + or - 0.4 gamma/sq cm per s above 0.5 PeV). The possibility of a long-term reduction in the luminosity of the PeV source by a factor of about 1.5/yr is also suggested by Haverah Park phase histograms of Cygnus X-3 obtained between January 1979 and December 1984, and by Plateau Rosa data from the December 1981 to March 1985 period. After accounting for losses in the PeV photon beam due to gamma-gamma interactions with the 2.7 K microwave background, the ultrahigh energy photon fluxes in the 10 to the 11th to 10 to the 12th eV region are found to be much lower than those of Cygnus X-3.

  2. High Resolution Spectroscopy of C_2 and CN in the Cygnus OB2 Association

    NASA Astrophysics Data System (ADS)

    McCall, Benjamin J.; Oka, Takeshi

    2000-08-01

    The unexpected detection of a large column density of hhh along the lines of sight to Cygnus OB2 #12 and Cygnus OB2 #5 cannot be explained by the standard models of diffuse cloud chemistry, which imply unreasonably long absorption path lengths (hundreds of parsecs). In order to gather more information about the physical condition of the diffuse gas in these lines of sight, we propose to obtain high resolution (R 120 000) visible spectra of several stars in the Cygnus OB2 association, including #12 and #5. The observed rotational distribution of the diatomics çand CN will enable us to estimate the kinetic temperature and number density of the molecular gas. In addition, the high resolution of the HRS at HET will allow us to study the velocity distribution of both the atomic (K I) and molecular (çand CN) gas along these lines of sight. Together with our previous observations of hhh, the temperatures, number densities, and velocity distributions from the proposed observations will seriously constrain theoretical models of these sightlines, such as that recently proposed by Cecchi-Pestellini and Dalgarno.

  3. PREDICTING GAIA’S PARALLAX DISTANCE TO THE CYGNUS OB2 ASSOCIATION WITH ECLIPSING BINARIES

    SciTech Connect

    Kiminki, Daniel C.; Kobulnicky, Henry A.; Álvarez, Carlos A. Vargas; Alexander, Michael J.; Lundquist, Michael J.

    2015-10-01

    The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the “Cygnus X” complex of star-forming regions and molecular clouds, its distance has proven elusive owing to the ambiguous nature of kinematic distances along this ℓ ≃ 80° sightline and the heavy, patchy extinction. In an effort to refine the three-dimensional geometry of key Cygnus X constituents, we have measured distances to four eclipsing double-lined OB-type spectroscopic binaries that are probable members of Cyg OB2. We find distances of 1.33 ± 0.17, 1.32 ± 0.07, 1.44 ± 0.18, and 1.32 ± 0.13 kpc toward MT91 372, MT91 696, CPR2002 A36, and Schulte 3, respectively. We adopt a weighted average distance of 1.33 ± 0.06 kpc. This agrees well with spectrophotometric estimates for the Association as a whole and with parallax measurements of protostellar masers in the surrounding interstellar clouds, thereby linking the ongoing star formation in these clouds with Cyg OB2. We also identify Schulte 3C (O9.5V), a 4″ visual companion to the 4.75 day binary Schulte 3(A+B), as a previously unrecognized Association member.

  4. An unidentified TeV source in the vicinity of Cygnus OB2

    NASA Astrophysics Data System (ADS)

    Aharonian, F.; Akhperjanian, A.; Beilicke, M.; Bernlöhr, K.; Börst, H.; Bojahr, H.; Bolz, O.; Coarasa, T.; Contreras, J.; Cortina, J.; Denninghoff, S.; Fonseca, V.; Girma, M.; Götting, N.; Heinzelmann, G.; Hermann, G.; Heusler, A.; Hofmann, W.; Horns, D.; Jung, I.; Kankanyan, R.; Kestel, M.; Kettler, J.; Kohnle, A.; Konopelko, A.; Kornmeyer, H.; Kranich, D.; Krawczynski, H.; Lampeitl, H.; Lopez, M.; Lorenz, E.; Lucarelli, F.; Magnussen, N.; Mang, O.; Meyer, H.; Milite, M.; Mirzoyan, R.; Moralejo, A.; Ona, E.; Panter, M.; Plyasheshnikov, A.; Prahl, J.; Pühlhofer, G.; Rauterberg, G.; Reyes, R.; Rhode, W.; Ripken, J.; Röhring, A.; Rowell, G. P.; Sahakian, V.; Samorski, M.; Schilling, M.; Schröder, F.; Siems, M.; Sobzynska, D.; Stamm, W.; Tluczykont, M.; Völk, H. J.; Wiedner, C. A.; Wittek, W.; Uchiyama, Y.; Takahashi, T.; HEGRA Collaboration

    2002-10-01

    Deep observation ( ~ 113 hrs) of the Cygnus region at TeV energies using the HEGRA stereoscopic system of air Čerenkov telescopes has serendipitously revealed a signal positionally inside the core of the OB association Cygnus OB2, at the edge of the 95% error circle of the EGRET source 3EG J2033+4118, and ~ 0.5o north of Cyg X-3. The source centre of gravity is RA alphaJ2000: 20h 32m 07s+/- 9.2sstat +/-2.2ssys, Dec deltaJ2000: +41o 30' 30''+/- 2.0'stat +/- 0.4'sys. The source is steady, has a post-trial significance of +4.6sigma , indication for extension with radius 5.6' at the ~ 3sigma level, and has a differential power-law flux with hard photon index of -1.9 +/-0.3stat +/-0.3sys. The integral flux above 1 TeV amounts ~ 3% that of the Crab. No counterpart for the TeV source at other wavelengths is presently identified, and its extension would disfavour an exclusive pulsar or AGN origin. If associated with Cygnus OB2, this dense concentration of young, massive stars provides an environment conducive to multi-TeV particle acceleration and likely subsequent interaction with a nearby gas cloud. Alternatively, one could envisage gamma -ray production via a jet-driven termination shock.

  5. GAMMA-RAY OBSERVATIONS OF CYGNUS X-1 ABOVE 100 MeV IN THE HARD AND SOFT STATES

    SciTech Connect

    Sabatini, S.; Tavani, M.; Del Santo, M.; Campana, R.; Evangelista, Y.; Piano, G.; Del Monte, E.; Giusti, M.; Striani, E.; Pooley, G.; Chen, A.; Giuliani, A.; Colafrancesco, S.; Longo, F.; Morselli, A.; Pellizzoni, A.; Pilia, M.; and others

    2013-04-01

    We present the results of multi-year gamma-ray observations by the AGILE satellite of the black hole binary system Cygnus X-1. In a previous investigation we focused on gamma-ray observations of Cygnus X-1 in the hard state during the period mid-2007/2009. Here we present the results of the gamma-ray monitoring of Cygnus X-1 during the period 2010/mid-2012 which includes a remarkably prolonged 'soft state' phase (2010 June-2011 May). Previous 1-10 MeV observations of Cyg X-1 in this state hinted at a possible existence of a non-thermal particle component with substantial modifications of the Comptonized emission from the inner accretion disk. Our AGILE data, averaged over the mid-2010/mid-2011 soft state of Cygnus X-1, provide a significant upper limit for gamma-ray emission above 100 MeV of F{sub soft} < 20 Multiplication-Sign 10{sup -8} photons cm{sup -2} s{sup -1} , excluding the existence of prominent non-thermal emission above 100 MeV during the soft state of Cygnus X-1. We discuss theoretical implications of our findings in the context of high-energy emission models of black hole accretion. We also discuss possible gamma-ray flares detected by AGILE. In addition to a previously reported episode observed by AGILE in 2009 October during the hard state, we report a weak but important candidate for enhanced emission which occurred at the end of 2010 June (2010 June 30 10:00-2010 July 2 10:00 UT) exactly coinciding with a hard-to-soft state transition and before an anomalous radio flare. An appendix summarizes all previous high-energy observations and possible detections of Cygnus X-1 above 1 MeV.

  6. Search for a periodic signal from Cygnus X-3 usingmuons observed underground in the Frejus detector (4800 mwe)

    NASA Technical Reports Server (NTRS)

    Bareyre, P.; Barloutaud, R.; Becker, K. H.; Behr, L.; Berger, C.; Bland, R. W.; Chardin, G.; Daum, H. J.; Degrange, B.; Demski, S.

    1986-01-01

    Periodic signals from Cygnus X-3 in the ultra high energy range were recently reported by air shower arrays and attributed to gamma rays. Although gamma rays are expected to produce muon-poor showers, the preceding observations have stimulated similar studies based on underground muons. Two groups have claimed a significant underground signal coming from Cygnus X-3. The results are, however, extremely difficult to explain in the present framework of particle physics, and clearly need confirmation. The preliminary results obtained from the Frejus underground detector during its first 16 months of operation (March 1984 to June 1985) are presented.

  7. VLBI Measurements of Plasma Turbulence Associated with the Cygnus OB1 Association

    NASA Astrophysics Data System (ADS)

    Spangler, Steven R.; Cordes, James M.

    1998-10-01

    We have made dual-frequency (1.67 and 5.00 GHz) VLBI observations of five compact, presumably extragalactic radio sources in the Galactic plane in the constellation of Cygnus. The lines of sight to these sources pass through a part of the interstellar medium that is modified by the Cygnus OB1 association. The VLBI observations were processed to yield measurements of the scattering measure due to interstellar plasma turbulence. The dual-frequency VLBI observations allowed estimates of the possible intrinsic structure contamination of the scattering measurements. Such an error is estimated to be less than 5% of the scattering measure for our two best-observed cases, and 15% to as high as 30% for a more weakly scattered source. Modeling the spatial power spectrum of the turbulence by Pδn(q) = C2Nq-α, where q is the spatial wavenumber of the turbulent fluctuations, our observations provide a measurement of 0LC2Ndz, where L is the thickness of the scattering medium and z is a coordinate along the line of sight. When combined with our earlier observations of the radio source 2013+370, we have a total of six lines of sight through the Cygnus OB1 association. Our observations show that the scattering through the Cygnus OB1 association is heavy and that the scattering measures vary from 0.14 to 2.21 m-20/3 kpc on lines of sight separated by as little as 1°-2°. When combined with measurements of the emission measure in the same directions, our scattering-measure results constrain properties of the turbulence in the Cygnus OB1 association. Specifically, if ε is the normalized amplitude of the density fluctuations, and l0 is the outer scale to the Kolmogorov spectrum, then our combined scattering measure-emission measure data set constrains the quantity ε2/(1+ε2)l2/30. The mean value is ~4.3 × 10-13 cm-2/3, with a range of about 0.5 in the logarithm. We do not have sufficient information to determine ε and l0 separately, but plausible ranges are ε < 1 and l0 < 3 pc

  8. New Evidence for a Black Hole in the Compact Binary Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Shrader, Chris R.; Titarchuk, Lev; Shaposhnikov, Nikolai

    2010-01-01

    The bright and highly variable X-ray and radio source known as Cygnus X-3 was among the first X-ray sources discovered, yet it remains in many ways an enigma. Its known to consist of a massive. Wolf-Rayet primary in an extremely tight orbit with a compact object. Yet one of the most basic of pa.ranietern the mass of the compact object - is not known. Nor is it even clear whether its is a neutron star or a black hole. In this Paper we present our analysis of the broad-band high-energy continua covering a substantial range in luminosity and spectral morphology. We apply these results to a recently identified scaling relationship which has been demonstrated to provide reliable estimates of the compact object mass in a number of accretion powered binaries. This analysis leads us to conclude that the compact object in Cygnus X-3 has a mass greater than 4.2 solar mass thus clearly indicative of a black hole and as such resolving a longstanding issue. The full range of uncertainty in our analysis and from using a. range of recently published distance estimates constrains the compact object mass to lie between 4.2 solar mass and 14.4 solar mass. Our favored estimate, based on a 9.0 kpc distance estimate is approx. l0 solar mass, with the. error margin of 3.2 solar masses. This result may thus pose challenges to shared-envelope evolutionary models of compact binaries. as well as establishing Cygnus X-3 as the first confirmed accretion-powered galactic gamma: ray source.

  9. Origin of multi-band emission from the microquasar Cygnus X-1

    SciTech Connect

    Zhang, Jianfu; Lu, Jufu; Xu, Bing

    2014-06-20

    We study the origin of non-thermal emissions from the Galactic black hole X-ray binary Cygnus X-1, which is a confirmed high-mass microquasar. By analogy with the methods used in studies of active galactic nuclei, we propose a two-dimensional, time-dependent radiation model from the microquasar Cygnus X-1. In this model, the evolution equation for relativistic electrons in a conical jet are numerically solved by including escape, adiabatic, and various radiative losses. The radiative processes involved are synchrotron emission, its self-Compton scattering, and inverse Compton scatterings of an accretion disk and its surrounding stellar companion. This model also includes an electromagnetic cascade process of an anisotropic γ-γ interaction. We study the spectral properties of electron evolution and its emission spectral characteristic at different heights of the emission region located in the jet. We find that radio data from Cygnus X-1 are reproduced by the synchrotron emission, the Fermi Large Area Telescope measurements by the synchrotron emission and Comptonization of photons of the stellar companion, and the TeV band emission fluxes by the Comptonization of the stellar photons. Our results show the following. (1) The radio emission region extends from the binary system scales to the termination of the jet. (2) The GeV band emissions should originate from the distance close to the binary system scales. (3) The TeV band emissions could be inside the binary system, and these emissions could be probed by the upcoming Cherenkov Telescope Array. (4) The MeV tail emissions, which produce a strongly linearly polarized signal, are emitted inside the binary system. The location of the emissions is very close to the inner region of the jet.

  10. Possible Charge-Exchange X-Ray Emission in the Cygnus Loop Detected with Suzaku

    NASA Technical Reports Server (NTRS)

    Katsuda, Satoru; Tsunemi, Hiroshi; Mori, Koji; Uchida, Hiroyuki; Kosugi, Hiroko; Kimura, Masashi; Nakajima, Hiroshi; Takakura, Satoru; Petre, Robert; Hewitt. John W.; Yamaguchi, Hiroya

    2011-01-01

    X-ray spectroscopic measurements of the Cygnus Loop supernova remnant indicate that metal abundances throughout most of the remnant s rim are depleted to approx.0.2 times the solar value. However, recent X-ray studies have revealed in some narrow regions along the outermost rim anomalously "enhanced" abundances (up to approx. 1 solar). The reason for these anomalous abundances is not understood. Here, we examine X-ray spectra in annular sectors covering nearly the entire rim of the Cygnus Loop using Suzaku (21 pointings) and XMM-Newton (1 pointing). We find that spectra in the "enhanced" abundance regions commonly show a strong emission feature at approx.0.7 keV. This feature is likely a complex of He-like O K(gamma + delta + epsilon), although other possibilities cannot be fully excluded. The intensity of this emission relative to He-like O K(alpha) appears to be too high to be explained as thermal emission. This fact, as well as the spatial concentration of the anomalous abundances in the outermost rim, leads us to propose an origin from charge-exchange processes between neutrals and H-like O. We show that the presence of charge-exchange emission could lead to the inference of apparently "enhanced" metal abundances using pure thermal emission models. Accounting for charge-exchange emission, the actual abundances could be uniformly low throughout the rim. The overall abundance depletion remains an open question. Subject headings: ISM: abundances ISM: individual objects (Cygnus Loop) ISM: supernova remnants X-rays: ISM atomic processes

  11. CIRCUMSTELLAR STRUCTURE AROUND EVOLVED STARS IN THE CYGNUS-X STAR FORMATION REGION

    SciTech Connect

    Kraemer, Kathleen E.; Price, Stephan D.

    2010-06-15

    We present observations of newly discovered 24 {mu}m circumstellar structures detected with MIPS around three evolved stars in the Cygnus-X star-forming region. One of the objects, BD+43 3710, has a bipolar nebula, possibly due to an outflow or a torus of material. A second, HBHA 4202-22, a Wolf-Rayet candidate, shows a circular shell of 24 {mu}m emission suggestive of either a limb-brightened shell or disk seen face-on. No diffuse emission was detected around either of these two objects in the Spitzer 3.6-8 {mu}m IRAC bands. The third object is the luminous blue variable candidate G79.29+0.46. We resolved the previously known inner ring in all four IRAC bands. The 24 {mu}m emission from the inner ring extends {approx}1.'2 beyond the shorter wavelength emission, well beyond what can be attributed to the difference in resolutions between MIPS and IRAC. Additionally, we have discovered an outer ring of 24 {mu}m emission, possibly due to an earlier episode of mass loss. For the two shell stars, we present the results of radiative transfer models, constraining the stellar and dust shell parameters. The shells are composed of amorphous carbon grains, plus polycyclic aromatic hydrocarbons in the case of G79.29+0.46. Both G79.29+0.46 and HBHA 4202-22 lie behind the main Cygnus-X cloud. Although G79.29+0.46 simply may be on the far side of the cloud, HBHA 4202-22 is unrelated to the Cygnus-X star formation region.

  12. Enhancement of the Forbidden Line in the Southwestern Knot of the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    Uchida, Hiroyuki; Tanaka, Takaaki; Katsuda, Satoru; Mori, Koji; Koyama, Katsuji; Tsunemi, Hiroshi

    We observed the southwestern knot (SW-K) of the Cygnus Loop supernova remnant with XMM-Newton RGS. The SW-K is one of the brightest and the most compact region in this remnant. The high energy resolution of RGS enables us to resolve details of the line complex of SW-K below ˜1 keV. We particularly focus on the OVII triplet in which the forbidden line is significantly enhanced relative to the resonance line. The measured forbidden-to-resonance line ratio is 1.75±0.13 which can not be explained by standard thermal plasma models such as collisional ionization equilibrium or ionizing plasmas. Recently, our comprehensive study of the Cygnus Loop with Suzaku XIS has found a possible sign of charge exchange (CX) from some points of its rim; their spectra always show a strong excess at ˜0.7 keV whose origin is likely a complex of cascade lines of He-like Oxygen (Kgamma+delta+epsilon). Since the SW-K is one of these regions, the RGS spectrum provides a conclusive information about the presence of the CX emission. It will also resolve a problem of the abundance inhomogeneity which is extensively seen in the Cygnus Loop and more importantly, will give us direct evidence for an interaction between ambient neutrals and ionized materials existing behind the shock. In this talk, we will also discuss other important possibilities such as the recombination or the resonance scattering for the SW-K spectrum. The RGS observation will cast a new light on the X-ray studies of shock-cloud interactions in SNRs ahead of the ASTRO-H era.

  13. NEW EVIDENCE FOR A BLACK HOLE IN THE COMPACT BINARY CYGNUS X-3

    SciTech Connect

    Shrader, Chris R.; Titarchuk, Lev; Shaposhnikov, Nikolai

    2010-07-20

    The bright and highly variable X-ray and radio source known as Cygnus X-3 was among the first X-ray sources discovered, yet it remains in many ways an enigma. It is known to consist of a massive, Wolf-Rayet primary in an extremely tight orbit with a compact object. However, one of the most basic of parameters-the mass of the compact object-is not known, nor is it even clear whether it is a neutron star or a black hole (BH). In this paper, we present our analysis of the broadband high-energy continua covering a substantial range in luminosity and spectral morphology. We apply these results to a recently identified scaling relationship that has been demonstrated to provide reliable estimates of the compact object mass in a number of accretion powered binaries. This analysis leads us to conclude that the compact object in Cygnus X-3 has a mass greater than 4.2 M{sub sun}, thus clearly indicative of a BH and as such, resolves a long-standing issue. The full range of uncertainty in our analysis and from using a range of recently published distance estimates constrain the compact object mass to lie between 4.2 M{sub sun} and 14.4 M{sub sun}. Our favored estimate, based on a 9.0 kpc distance estimate, is {approx}10 M{sub sun}, with an error margin of 3.2 solar masses. This result may thus pose challenges to shared-envelope evolutionary models of compact binaries, as well as establishing Cygnus X-3 as the first confirmed accretion-powered galactic gamma-ray source.

  14. NuSTAR Observations of the Powerful Radio Galaxy Cygnus A

    NASA Astrophysics Data System (ADS)

    Reynolds, Christopher S.; Lohfink, Anne M.; Ogle, Patrick M.; Harrison, Fiona A.; Madsen, Kristin K.; Fabian, Andrew C.; Wik, Daniel R.; Madejski, Grzegorz; Ballantyne, David R.; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Fuerst, Felix; Hailey, Charles J.; Lanz, Lauranne; Miller, Jon M.; Saez, Cristian; Stern, Daniel; Walton, Dominic J.; Zhang, William

    2015-08-01

    We present NuSTAR observations of the powerful radio galaxy Cygnus A, focusing on the central absorbed active galactic nucleus (AGN). Cygnus A is embedded in a cool-core galaxy cluster, and hence we also examine archival XMM-Newton data to facilitate the decomposition of the spectrum into the AGN and intracluster medium components. NuSTAR gives a source-dominated spectrum of the AGN out to \\gt 70 keV. In gross terms, the NuSTAR spectrum of the AGN has the form of a power law ({{Γ }}∼ 1.6-1.7) absorbed by a neutral column density of {N}{{H}}∼ 1.6× {10}23 {{cm}}-2. However, we also detect curvature in the hard (\\gt 10 keV) spectrum resulting from reflection by Compton-thick matter out of our line of sight to the X-ray source. Compton reflection, possibly from the outer accretion disk or obscuring torus, is required even permitting a high-energy cut off in the continuum source; the limit on the cut-off energy is {E}{cut}\\gt 111 keV(90% confidence). Interestingly, the absorbed power law plus reflection model leaves residuals suggesting the absorption/emission from a fast (15,000-26,000 {km} {{{s}}}-1 ), high column-density ({N}W\\gt 3× {10}23 {{cm}}-2), highly ionized (ξ ∼ 2500 {erg} {cm} {{{s}}}-1) wind. A second, even faster ionized wind component is also suggested by these data. We show that the ionized wind likely carries a significant mass and momentum flux, and may carry sufficient kinetic energy to exercise feedback on the host galaxy. If confirmed, the simultaneous presence of a strong wind and powerful jets in Cygnus A demonstrates that feedback from radio-jets and sub-relativistic winds are not mutually exclusive phases of AGN activity but can occur simultaneously.

  15. Angular resolution studies of the CYGNUS array using the shadows of the sun and moon

    SciTech Connect

    Shoup, A.L.

    1993-01-01

    Using the cosmic ray shadows of the sun and moon, we have estimated the angular resolution of the CYGNUS extensive air shower array. With the event sample now available we estimate the angular resolution of the array to be 0.70[sub [minus]0.06][sup [plus]0.07] degrees. The resolution depends on the total number of detected shower particles. A new parameterization of the measured shower-front timing structure and the use of counters with small pulse areas lead to a [approximately]25% improvement in the resolution. The systematic pointing error of the array is less than 0.4[degree].

  16. Angular resolution studies of the CYGNUS array using the shadows of the sun and moon

    SciTech Connect

    Shoup, A.L.; The CYGNUS Collaboration

    1993-05-01

    Using the cosmic ray shadows of the sun and moon, we have estimated the angular resolution of the CYGNUS extensive air shower array. With the event sample now available we estimate the angular resolution of the array to be 0.70{sub {minus}0.06}{sup {plus}0.07} degrees. The resolution depends on the total number of detected shower particles. A new parameterization of the measured shower-front timing structure and the use of counters with small pulse areas lead to a {approximately}25% improvement in the resolution. The systematic pointing error of the array is less than 0.4{degree}.

  17. The beginning of a giant radio flare from Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Trushkin, S. A.; Nizhelskij, N. A.; Tsybulev, P. G.; Zhekanis, G. V.

    2016-09-01

    As we suggested in ATel #9416, galactic microquasar Cygnus X-3 is currently undergoing a flaring activity. If on 30 August 2016 (MJD 57630.798) its fluxes were 120-128 mJy at 4.6, 8.2, 11.2 GHz in the RATAN-600 radio telescope observations, then on 31 August (MJD 57631.795) the fluxes became 60, 300, 570, 740, 800 mJy at 2.3, 4.6, 8.2, 11.2 and 21.7 GHz with typical errors about 3-7%.

  18. Long-term studies with the Ariel 5 ASM. II - The strong Cygnus sources

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Kaluzienski, L. J.; Boldt, E. A.; Serlemitsos, P. J.

    1979-01-01

    The three bright 3-6 keV X-ray sources in Cygnus are examined for regular temporal variability with a 1300 day record from the Ariel 5 All-Sky Monitor. The only periods consistently observed are 5.6 days for Cyg X-1, 11.23 days for Cyg X-2, and 4.8 hours for Cyg X-3. The 78.4 day period of Kemp, Herman, and Barbour for Cyg X-1, the 9.843 day period of Cowley, Crampton, and Hutchings for Cyg X-2, and the 16.75 day period of Holt et al. for Cyg X-3 are not confirmed.

  19. Detection of H3+ in the diffuse interstellar medium toward Cygnus OB2 No. 12.

    PubMed

    McCall, B J; Geballe, T R; Hinkle, K H; Oka, T

    1998-03-20

    The molecular ion H3+ is considered the cornerstone of interstellar chemistry because it initiates the reactions responsible for the production of many larger molecules. Recently discovered in dense molecular clouds, H3+ has now been observed in the diffuse interstellar medium toward Cygnus OB2 No. 12. Analysis of H3+ chemistry suggests that the high H3+ column density (3.8 x 10(14) per square centimeter) is due not to a high H3+ concentration but to a long absorption path. This and other work demonstrate the ubiquity of H3+ and its potential as a probe of the physical and chemical conditions in the interstellar medium.

  20. Fermi-LAT Detection of a Gamma-ray Flare from Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Cheung, C. C.; Loh, Alan

    2016-09-01

    The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed a gamma-ray flare from the high-mass X-ray binary Cygnus X-3. Preliminary analysis indicates that on 2016 September 15 and 16, the gamma-ray source was observed with respective daily averaged fluxes (E > 100MeV) of (2.2+/-0.4) x 10^-6 photons cm^-2 s^-1 and (2.8+/-0.4) x 10^-6 photons cm^-2 s^-1 (errors are statistical only).

  1. AGILE Detection of Gamma-Ray Emission from the Microquasar Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Piano, G.; Tavani, M.; Bulgarelli, A.; Verrecchia, F.; Donnarumma, I.; Munar-Adrover, P.; Minervini, G.; Fioretti, V.; Zoli, A.; Pittori, C.; Lucarelli, F.; Vercellone, S.; Striani, E.; Cardillo, M.; Gianotti, F.; Trifoglio, M.; Giuliani, A.; Mereghetti, S.; Caraveo, P.; Perotti, F.; Chen, A.; Argan, A.; Costa, E.; Del Monte, E.; Evangelista, Y.; Feroci, M.; Lazzarotto, F.; Lapshov, I.; Pacciani, L.; Soffitta, P.; Sabatini, S.; Vittorini, V.; Pucella, G.; Rapisarda, M.; Di Cocco, G.; Fuschino, F.; Galli, M.; Labanti, C.; Marisaldi, M.; Pellizzoni, A.; Pilia, M.; Trois, A.; Barbiellini, G.; Vallazza, E.; Longo, F.; Morselli, A.; Picozza, P.; Prest, M.; Lipari, P.; Zanello, D.; Cattaneo, P. W.; Rappoldi, A.; Colafrancesco, S.; Parmiggiani, N.; Ferrari, A.; Antonelli, A.; Giommi, P.; Salotti, L.; Valentini, G.; D'Amico, F.

    2016-08-01

    The AGILE-GRID detector is revealing gamma-ray emission above 100 MeV from a source positionally consistent with the microquasar Cygnus X-3. Integrating from 2016-08-28 UT 09:00:00 to 2016-08-30 UT 09:00:00 (MJD: 57628.375 - 57630.375), a preliminary multi-source likelihood analysis detects a gamma-ray flux F( > 100 MeV) = (4.0 +/- 1.4) x 10^-6 photons/cm^2/s with a significance near 4 sigma.

  2. Enhanced gamma-ray emission from the microquasar Cygnus X-3 detected by AGILE

    NASA Astrophysics Data System (ADS)

    Piano, G.; Pittori, C.; Verrecchia, F.; Tavani, M.; Bulgarelli, A.; Fioretti, V.; Zoli, A.; Munar-Adrover, P.; Lucarelli, F.; Donnarumma, I.; Vercellone, S.; Striani, E.; Cardillo, M.; Gianotti, F.; Trifoglio, M.; Giuliani, A.; Mereghetti, S.; Caraveo, P.; Perotti, F.; Chen, A.; Argan, A.; Costa, E.; Del Monte, E.; Evangelista, Y.; Feroci, M.; Lazzarotto, F.; Lapshov, I.; Pacciani, L.; Soffitta, P.; Sabatini, S.; Vittorini, V.; Pucella, G.; Rapisarda, M.; Di Cocco, G.; Fuschino, F.; Galli, M.; Labanti, C.; Marisaldi, M.; Pellizzoni, A.; Pilia, M.; Trois, A.; Barbiellini, G.; Vallazza, E.; Longo, F.; Morselli, A.; Picozza, P.; Prest, M.; Lipari, P.; Zanello, D.; Cattaneo, P. W.; Rappoldi, A.; Colafrancesco, S.; Parmiggiani, N.; Ferrari, A.; Antonelli, A.; Giommi, P.; Salotti, L.; Valentini, G.; D'Amico, F.

    2016-04-01

    Integrating from 2016-04-16 00:00 UT to 2016-04-19 00:00 UT, the AGILE-GRID detector is revealing gamma-ray emission above 100 MeV from a source positionally consistent with Cygnus X-3 at Galactic coordinates (l, b) = (79.4, 0.2) +/- 0.6 (stat.) +/- 0.1 (syst.) deg, with flux F( > 100 MeV) = (2.0 +/- 0.8) x 10^-6 photons/cm^2/s, as determined by a multi-source likelihood analysis.

  3. Nine New Variable Stars in Cygnus and Variability Type Determination of [Wm2007] 1176

    NASA Astrophysics Data System (ADS)

    Furgoni, R.

    2013-06-01

    I report the discovery of nine new variable stars in Cygnus: five pulsating (VSX J192319.8+280832, VSX J192405.8+280352, VSX J192220.7+275518, VSX J192304.4+280231, VSX J192255.1+274744) and four eclipsing (VSX J192252.4+280217, VSX J192251.4+280456, VSX J192226.0+281019, VSX J192524.9+275342). The variability type of the variable star [WM2007] 1176, that was considered in literature a possible RRC, was found to be a W UMa variable with an obvious O'Connell effect.

  4. Identification of the TeV gamma-ray source ARGO J2031+4157 with the Cygnus Cocoon

    SciTech Connect

    Bartoli, B.; Catalanotti, S.; D'Ettorre Piazzoli, B.; Di Girolamo, T.; Bernardini, P.; D'Amone, A.; De Mitri, I.; Bi, X. J.; Cao, Z.; Chen, S. Z.; Branchini, P.; Budano, A.; Camarri, P.; Cardarelli, R.; Di Sciascio, G.; Chen, T. L.; Danzengluobu; Creti, P.; Cui, S. W.; Dai, B. Z.; Collaboration: ARGO-YBJ Collaboration; and others

    2014-08-01

    The extended TeV gamma-ray source ARGO J2031+4157 (or MGRO J2031+41) is positionally consistent with the Cygnus Cocoon discovered by Fermi-LAT at GeV energies in the Cygnus superbubble. Reanalyzing the ARGO-YBJ data collected from 2007 November to 2013 January, the angular extension and energy spectrum of ARGO J2031+4157 are evaluated. After subtracting the contribution of the overlapping TeV sources, the ARGO-YBJ excess map is fitted with a two-dimensional Gaussian function in a square region of 10° × 10°, finding a source extension σ{sub ext}= 1.°8 ± 0.°5. The observed differential energy spectrum is dN/dE = (2.5 ± 0.4) × 10{sup –11}(E/1 TeV){sup –2.6±0.3} photons cm{sup –2} s{sup –1} TeV{sup –1}, in the energy range 0.2-10 TeV. The angular extension is consistent with that of the Cygnus Cocoon as measured by Fermi-LAT and the spectrum also shows a good connection with the one measured in the 1-100 GeV energy range. These features suggest to identify ARGO J2031+4157 as the counterpart of the Cygnus Cocoon at TeV energies. The Cygnus Cocoon, located in the star-forming region of Cygnus X, is interpreted as a cocoon of freshly accelerated cosmic rays related to the Cygnus superbubble. The spectral similarity with supernova remnants (SNRs) indicates that the particle acceleration inside a superbubble is similar to that in an SNR. The spectral measurements from 1 GeV to 10 TeV allows for the first time to determine the possible spectrum slope of the underlying particle distribution. A hadronic model is adopted to explain the spectral energy distribution.

  5. MAGIC CONSTRAINTS ON {gamma}-RAY EMISSION FROM CYGNUS X-3

    SciTech Connect

    Aleksic, J.; Blanch, O.; Antonelli, L. A.; Bonnoli, G.; Antoranz, P.; Backes, M.; Baixeras, C.; Barrio, J. A.; Bastieri, D.; Gonzalez, J. Becerra; Bednarek, W.; Berdyugin, A.; Berger, K.; Bernardini, E.; Biland, A.; Boller, A.; Bock, R. K.; Tridon, D. Borla; Bordas, P.; Bosch-Ramon, V. E-mail: tysaito@mpp.mpg.d

    2010-09-20

    Cygnus X-3 is a microquasar consisting of an accreting compact object orbiting around a Wolf-Rayet star. It has been detected at radio frequencies and up to high-energy {gamma} rays (above 100 MeV). However, many models also predict a very high energy (VHE) emission (above hundreds of GeV) when the source displays relativistic persistent jets or transient ejections. Therefore, detecting such emission would improve the understanding of the jet physics. The imaging atmospheric Cherenkov telescope MAGIC observed Cygnus X-3 for about 70 hr between 2006 March and 2009 August in different X-ray/radio spectral states and also during a period of enhanced {gamma}-ray emission. MAGIC found no evidence for a VHE signal from the direction of the microquasar. An upper limit to the integral flux for energies higher than 250 GeV has been set to 2.2 x 10{sup -12} photons cm{sup -2} s{sup -1} (95% confidence level). This is the best limit so far to the VHE emission from this source. The non-detection of a VHE signal during the period of activity in the high-energy band sheds light on the location of the possible VHE radiation favoring the emission from the innermost region of the jets, where absorption is significant. The current and future generations of Cherenkov telescopes may detect a signal under precise spectral conditions.

  6. The Extreme Spin of the Black Hole in Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Gou, Lijun; McClintock, Jeffrey E.; Reid, Mark J.; Orosz, Jerome A.; Steiner, James F.; Narayan, Ramesh; Xiang, Jingen; Remillard, Ronald A.; Arnaud, Keith A.; Davis, Shane W.

    2011-01-01

    The compact primary in the X-ray binary Cygnus X-1 was the first black hole to be established via dynamical observations. We have recently determined accurate values for its mass and distance, and for the orbital inclination angle of the binary. Building on these results, which are based on our favored (asynchronous) dynamical model, we have measured the radius of the inner edge of the black hole s accretion disk by fitting its thermal continuum spectrum to a fully relativistic model of a thin accretion disk. Assuming that the spin axis of the black hole is aligned with the orbital angular momentum vector, we have determined that Cygnus X-1 contains a near-extreme Kerr black hole with a spin parameter a* > 0.95 (3(sigma)). For a less probable (synchronous) dynamical model, we find a. > 0.92 (3 ). In our analysis, we include the uncertainties in black hole mass, orbital inclination angle, and distance, and we also include the uncertainty in the calibration of the absolute flux via the Crab. These four sources of uncertainty totally dominate the error budget. The uncertainties introduced by the thin-disk model we employ are particularly small in this case given the extreme spin of the black hole and the disk s low luminosity.

  7. The Nuclear Jet and Counterjet Region of the Radio Galaxy Cygnus A

    NASA Astrophysics Data System (ADS)

    Bartel, N.; Sorathia, B.; Bietenholz, M. F.; Carilli, C. L.; Diamond, P.

    1995-12-01

    Very-long-baseline interferometry images of the nuclear region of the radio galaxy Cygnus A reveal a pronounced "core" and a knotty jet and counterjet. The knots are moving away from the core at apparent speeds which are subluminal for h = 1 [h = H_0/100 km.s-1.Mpc-1;1 parsec (pc) = 3.09 x 1016m] and about c for h = 0.5. The jet is aligned with the outer, kiloparsec-scale jet to within 2^circ. The counterjet has a total flux density at 5 GHz of about one-fifth of that of the jet. In the context of the twin relativistic jet model for active galactic nuclei, the jet in Cygnus A is oriented at an angle to our line of sight of 35-80^circ and 55-85^circ, and the intrinsic velocity of the jet fluid is 0.4-0.6c and 0.6-1c for h = 1 and h = 0.5, respectively.

  8. The nuclear jet and counterjet region of the radio galaxy Cygnus A.

    PubMed Central

    Bartel, N; Sorathia, B; Bietenholz, M F; Carilli, C L; Diamond, P

    1995-01-01

    Very-long-baseline interferometry images of the nuclear region of the radio galaxy Cygnus A reveal a pronounced "core" and a knotty jet and counterjet. The knots are moving away from the core at apparent speeds which are subluminal for h = 1 [h = H0/100 km.s-1.Mpc-1;1 parsec (pc) = 3.09 x 10(16)m] and about c for h = 0.5. The jet is aligned with the outer, kiloparsec-scale jet to within 2 degrees. The counterjet has a total flux density at 5 GHz of about one-fifth of that of the jet. In the context of the twin relativistic jet model for active galactic nuclei, the jet in Cygnus A is oriented at an angle to our line of sight of 35-80 degrees and 55-85 degrees, and the intrinsic velocity of the jet fluid is 0.4-0.6c and 0.6-1c for h = 1 and h = 0.5, respectively. PMID:11607600

  9. A dark jet dominates the power output of the stellar black hole Cygnus X-1.

    PubMed

    Gallo, Elena; Fender, Rob; Kaiser, Christian; Russell, David; Morganti, Raffaella; Oosterloo, Tom; Heinz, Sebastian

    2005-08-11

    Black holes undergoing accretion are thought to emit the bulk of their power in the X-ray band by releasing the gravitational potential energy of the infalling matter. At the same time, they are capable of producing highly collimated jets of energy and particles flowing out of the system with relativistic velocities. Here we show that the 10-solar-mass (10M(o)) black hole in the X-ray binary Cygnus X-1 (refs 3-5) is surrounded by a large-scale (approximately 5 pc in diameter) ring-like structure that appears to be inflated by the inner radio jet. We estimate that in order to sustain the observed emission of the ring, the jet of Cygnus X-1 has to carry a kinetic power that can be as high as the bolometric X-ray luminosity of the binary system. This result may imply that low-luminosity stellar-mass black holes as a whole dissipate the bulk of the liberated accretion power in the form of 'dark', radiatively inefficient relativistic outflows, rather than locally in the X-ray-emitting inflow.

  10. Discovery of TeV Gamma-Ray Emission from the Cygnus Region

    SciTech Connect

    Abdo, A.A.; Allen, B.; Berley, D.; Blaufuss, E.; Casanova, S.; Chen, C.; Coyne, D.G.; Delay, R.S.; Dingus, B.L.; Ellsworth, R.W.; Fleysher, L.; Fleysher, R.; Gonzalez, M.M.; Goodman, J.A.; Hays, E.; Hoffman, C.M.; Kolterman, B.E.; Kelley, L.A.; Lansdell, C.P.; Linnemann, J.T.; McEnery, J.E.

    2006-11-28

    The diffuse gamma radiation arising from the interaction of cosmic ray particles with matter and radiation in the Galaxy is one of the few probes available to study the origin of the cosmic rays. Milagro is a water Cherenkov detector that continuously views the entire overhead sky. The large field-of-view combined with the long observation time makes Milagro the most sensitive instrument available for the study of large, low surface brightness sources such as the diffuse gamma radiation arising from interactions of cosmic radiation with interstellar matter. In this paper we present spatial and flux measurements of TeV gamma-ray emission from the Cygnus Region. The TeV image shows at least one new source MGRO J2019+37 as well as correlations with the matter density in the region as would be expected from cosmic-ray proton interactions. However, the TeV gamma-ray flux as measured at {approx}12 TeV from the Cygnus region (after excluding MGRO J2019+37) exceeds that predicted from a conventional model of cosmic ray production and propagation. This observation indicates the existence of either hard-spectrum cosmic-ray sources and/or other sources of TeV gamma rays in the region.

  11. The Extreme Spin of the Black Hole in Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Gou, Lijun; McClintock, Jeffre E.; Reid, Mark J.; Orosz, Jerome A.; Steiner, James F.; Narayan, Ramesh; Xiang, Jingen; Remillard, Ronald A.; Arnaud, Keith A.; Davis, Shane W.

    2005-01-01

    The compact primary in the X-ray binary Cygnus X-1 was the first black hole to be established via dynamical observatIOns. We have recently determined accurate values for its mass and distance, and for the orbital inclination angle of the binary. Building on these.results, which are based on our favored (asynchronous) dynamical model, we have measured the radius of the inner edge of the black hole's accretion disk by fitting its thermal continuum.spectrum to a fully relativistic model of a thin accretion disk. Assuming that the spin axis of the black hole is aligned with the orbital angular momentum vector, we have determined that Cygnus X-I contains a near-extreme Kerr black hole with a spin parameter a* > 0.95 (3(sigma)). For a less probable (synchronous) dynamIcal model, we find a* > 0.92 (3(sigma)). In our analysis, we include the uncertainties in black hole mass orbital inclination angle and distance, and we also include the uncertainty in the calibration of the absolute flux via the Crab. These four sources of uncertainty totally dominate the error budget. The uncertainties introduced by the thin-disk model we employ are particularly small in this case given the extreme spin of the black hole and the disk's low luminosity.

  12. LOFAR imaging of Cygnus A - Direct detection of a turnover in the hotspot radio spectra

    NASA Astrophysics Data System (ADS)

    McKean, J. P.; Godfrey, L. E. H.; Vegetti, S.; Wise, M. W.; Morganti, R.; Hardcastle, M. J.; Rafferty, D.; Anderson, J.; Avruch, I. M.; Beck, R.; Bell, M. E.; van Bemmel, I.; Bentum, M. J.; Bernardi, G.; Best, P.; Blaauw, R.; Bonafede, A.; Breitling, F.; Broderick, J. W.; Brüggen, M.; Cerrigone, L.; Ciardi, B.; de Gasperin, F.; Deller, A.; Duscha, S.; Engels, D.; Falcke, H.; Fallows, R. A.; Frieswijk, W.; Garrett, M. A.; Grießmeier, J. M.; van Haarlem, M. P.; Heald, G.; Hoeft, M.; Horst, A. J. van der; Iacobelli, M.; Intema, H.; Juette, E.; Karastergiou, A.; Kondratiev, V. I.; Koopmans, L. V. E.; Kuniyoshi, M.; Kuper, G.; van Leeuwen, J.; Maat, P.; Mann, G.; Markoff, S.; McFadden, R.; McKay-Bukowski, D.; Mulcahy, D. D.; Munk, H.; Nelles, A.; Orru, E.; Paas, H.; Pandey-Pommier, M.; Pietka, M.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Röttgering, H. J.. A.; Rowlinson, A.; Scaife, A. M. M.; Serylak, M.; Shulevski, A.; Sluman, J.; Smirnov, O.; Steinmetz, M.; Stewart, A.; Swinbank, J.; Tagger, M.; Thoudam, S.; Toribio, M. C.; Vermeulen, R.; Vocks, C.; van Weeren, R. J.; Wucknitz, O.; Yatawatta, S.; Zarka, P.

    2016-08-01

    The low-frequency radio spectra of the hotspots within powerful radio galaxies can provide valuable information about the physical processes operating at the site of the jet termination. These processes are responsible for the dissipation of jet kinetic energy, particle acceleration, and magnetic-field generation. Here we report new observations of the powerful radio galaxy Cygnus A using the Low Frequency Array (LOFAR) between 109 and 183 MHz, at an angular resolution of ˜3.5 arcsec. The radio emission of the lobes is found to have a complex spectral index distribution, with a spectral steepening found towards the centre of the source. For the first time, a turnover in the radio spectrum of the two main hotspots of Cygnus A has been directly observed. By combining our LOFAR imaging with data from the Very Large Array at higher frequencies, we show that the very rapid turnover in the hotspot spectra cannot be explained by a low-energy cut-off in the electron energy distribution, as has been previously suggested. Thermal (free-free) absorption or synchrotron self absorption models are able to describe the low-frequency spectral shape of the hotspots, however, as with previous studies, we find that the implied model parameters are unlikely, and interpreting the spectra of the hotspots remains problematic.

  13. On the orbital and physical parameters of the HDE 226868/Cygnus X-1 binary system

    NASA Astrophysics Data System (ADS)

    Iorio, Lorenzo

    2008-06-01

    In this paper we explore the consequences of the recent determination of the mass m=(8.7±0.8) M ⊙ of Cygnus X-1, obtained from the Quasi-Periodic Oscillation (QPO)-photon index correlation scaling, on the orbital and physical properties of the binary system HDE 226868/Cygnus X-1. By using such a result and the latest spectroscopic optical data of the HDE 226868 supergiant star we get M=(24±5) M ⊙ for its mass. It turns out that deviations from the third Kepler law significant at more than 1-sigma level would occur if the inclination i of the system’s orbital plane to the plane of the sky falls outside the range ≈41 56 deg: such deviations cannot be due to the first post-Newtonian (1PN) correction to the orbital period because of its smallness; interpreted in the framework of the Newtonian theory of gravitation as due to the stellar quadrupole mass moment Q, they are unphysical because Q would take unreasonably large values. By conservatively assuming that the third Kepler law is an adequate model for the orbital period we obtain i=(48±7) deg which yields for the relative semimajor axis a=(42±9) R ⊙ (≈0.2 AU).

  14. THE EXTREME SPIN OF THE BLACK HOLE IN CYGNUS X-1

    SciTech Connect

    Gou Lijun; McClintock, Jeffrey E.; Reid, Mark J.; Steiner, James F.; Narayan, Ramesh; Xiang, Jingen; Orosz, Jerome A.; Remillard, Ronald A.; Arnaud, Keith A.; Davis, Shane W.

    2011-12-01

    The compact primary in the X-ray binary Cygnus X-1 was the first black hole to be established via dynamical observations. We have recently determined accurate values for its mass and distance, and for the orbital inclination angle of the binary. Building on these results, which are based on our favored (asynchronous) dynamical model, we have measured the radius of the inner edge of the black hole's accretion disk by fitting its thermal continuum spectrum to a fully relativistic model of a thin accretion disk. Assuming that the spin axis of the black hole is aligned with the orbital angular momentum vector, we have determined that Cygnus X-1 contains a near-extreme Kerr black hole with a spin parameter a{sub *} > 0.95 (3{sigma}). For a less probable (synchronous) dynamical model, we find a{sub *} > 0.92 (3{sigma}). In our analysis, we include the uncertainties in black hole mass, orbital inclination angle, and distance, and we also include the uncertainty in the calibration of the absolute flux via the Crab. These four sources of uncertainty totally dominate the error budget. The uncertainties introduced by the thin-disk model we employ are particularly small in this case given the extreme spin of the black hole and the disk's low luminosity.

  15. Understanding Black Hole X-ray Binaries: The Case of Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Pottschmidt, Katja

    2008-01-01

    Black Hole X-ray Binaries are known to display distinct emission states that differ in their X-ray spectra, their X-ray timing properties (on times scales less than 1 s) and their radio emission. In recent years monitoring observations, specially with NASA's Rossi X-ray Timing Explorer (RXTE), have provided us with detailed empirical modeling of the phenomenology of the different states as well as a unification scheme of the long term evolution of black holes, transient and persistent, in terms of these states. Observations of the persistent High Mass X-ray Binary (HMXB) Cygnus X-l have been at the forefront of learning about black hole states since its optical identification through a state transition in 1973. In this talk I will present in depth studies of several different aspects of the accretion process in this system. The main data base for these studies is an ongoing RXTE and Ryle radio telescope bi-weekly monitoring campaign that started in 1997. I will discuss high-resolution timing results, especially power spectra, which first gave rise to the Lorentzian description now widely used for black hole and neutron star binaries, and time lags, which we found to be especially well suited to identify state transitions. The evolution of spectral, timing, and radio parameters over years will be shown, including the rms-flux relation and the observation of a clearly correlated radio/x-ray flare. We also observed Cygnus X-1 with INTEGRAL, which allowed us to extend timing and spectral studies to higher energies, with XMM, which provided strong constraints on the parameters of the 6.4 keV iron fluorescence line, and with Chandra, which provided the most in depth study to date of the stellar wind in this system. Models based on the physical conditions in the accretion region are still mainly concentrated on the one or other of the observational areas but they are expanding: as an example I will review results from a jet model for the quantitative description of the

  16. Gamma-Ray Spectra and Variability of Cygnus Z-1 Observed by BATSE

    NASA Technical Reports Server (NTRS)

    Ling, J. C.; Wheaton, William A.; Wallyn, P.; Mahoney, W. .; Paciesas, W. S.; Harmon, B. A.; Fishman, G. J.; Zhang, S. N.; Hua, X. M.

    1998-01-01

    We present new BATSE earth occultation observations of the 25 keV-1.8 MeV spectrum and variability of Cygnus X-1 made between August 1993 and May 1994. We observed that the normal soft gamma ray spectrum (gamma2) of Cygnus X-1 has two components: a Comptonized part seen below 300 keV, and a high-energy tail in the 0.3 - 2 MeV range. We interpret it in terms of a two-layer region, consisting of a high-energy core (with an equivalent electron temperature of approximately 210-250 keV) near the event horizon, embedded in an about 50 keV corona. In this scenario, the observed 25-300 keV photons were produced by Compton scattering of soft photons (about 0.5 keV) by the hot electrons in the outer corona. These same hard x rays were further up-scattered by a population of energetic electrons in the inner core, producing the spectral tail above 300 keV. Cygnus X-1 went through an extended sequence of transitions between August 1993 and May 1994, when the 45-140 keV flux first decreased steadily from approximately gamma2 to roughly one-quarter of its intensity over a period of about 140 days. The flux remained at this low level for about 40 days before returning, swiftly (approximately 20 days) to approximately the initial gamma2 level. During the transition, the spectrum evolved to a shape consistent with either a power law with photon index of about 2.6 or a single temperature Compton model with electron temperature kT = 110 +/- 11 keV, and optical depth t = 0.40 +/- 0.06, and then returned essentially to the original gamma2 spectrum at the end of the active period. The overall cooling of the system during the low flux period may be due to an increase in the soft photon population which effectively quenched the hot electrons in these regions through Compton scattering.

  17. Origin of ultra-high-energy gamma-rays from Cygnus X-3 and related sources

    NASA Technical Reports Server (NTRS)

    Kazanas, D.; Ellison, D. C.

    1986-01-01

    Diffusive shock acceleration of ions is examined as the mechanism responsible for the ultrahigh energy (UHE) gamma ray emission observed from Cygnus X-3 and several other binary X-ray sources at energies of 10 to the 15th eV and higher. The shock acceleration can under reasonable assumptions be sufficiently short to allow acceleration of ions to energies near 10 to the 16th eV. It is proposed that the subsequent proton-proton collisions and photodissociation of He-4 can produce a flux of neutrons that escapes from the acceleration site despite high magnetic fields. These neutrons, by interacting with the binary companion, produce the observed UHE radiation.

  18. Fatal verminous pharyngitis and esophagitis caused by Streptocara incognita in mute swans (Cygnus olor).

    PubMed

    Alić, A; Prasović, S; Hodzić, A; Besirović, H; Residbegović, Emina; Omeragić, J

    2013-03-01

    Streptocara spp. infections are reported to cause gastritis, proventriculitis, esophagitis, and pharyngitis in various waterfowls, especially diving ducks. In the present paper, we describe severe fatal diphtheritic pharyngitis and esophagitis caused by Streptocara incognita in three female mute swans (Cygnus olor) in Bosnia and Herzegovina. Prior to death, the swans were showing signs of lethargy, anorexia, and reluctance to move. At necropsy, in all swans severe diphtheritic pharyngitis and esophagitis with deep, dark red hemorrhagic ulcerations were observed. Numerous thin, white, up to 1-cm-long nematodes, identified as S. incognita, were observed embedded in the pharyngeal and esophageal mucosa under the diphtheritic membranes. Histopathology revealed severe fibrinonecrotic inflammation with numerous cross-sections of the parasites. To the authors' knowledge, this is the first report of severe, fatal streptocariasis in mute swans. PMID:23678745

  19. Polarized Gamma-Ray Emission from the Galactic Black Hole Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Laurent, P.; Rodriquez, J.; Wilms, J.; Bel, M. Cadolle; Pottschmidt, K.; Grinberg, V.

    2011-01-01

    Because of their inherently high flux allowing the detection of clear signals, black hole X-ray binaries are interesting candidates for polarization studies, even if no polarization signals have been observed from them before. Such measurements would provide further detailed insight into these sources' emission mechanisms. We measured the polarization of the gamma-ray emission from the black hole binary system Cygnus X-I with the INTEGRAL/IBIS telescope. Spectral modeling ofthe data reveals two emission mechanisms: The 250-400 keY data are consistent with emission dominated by Compton scattering on thermal electrons and are weakly polarized. The second spectral component seen in the 400keV-2MeV band is by contrast strongly polarized, revealing that the MeV emission is probably related to the jet first detected in the radio band.

  20. VizieR Online Data Catalog: Young and embedded clusters in Cygnus-X (Maia+, 2016)

    NASA Astrophysics Data System (ADS)

    Maia, F. F. S.; Moraux, E.; Joncour, I.

    2016-02-01

    CFHT/WIRCam was used to acquire deep (960s, 1200s, 480s) JHK exposures of five fields covering ~1 degree squared in the Cygnus-X complex, in six nights between 04/09/2012 and 29/10/2012. The frames were detrended and coadded into a master mosaic where PSF photometry was carried out using SExtractor and PSFex software using a 2-sigma detection threshold. The resulting catalog was calibrated against the 2MASS catalog, but no transformation was done to our data. Instead, bright sources (brighter than the saturation magnitude) were recovered from 2MASS and calibrated to the WIRCam instrumental system to complement our catalog. The final table contains about 310000 stars spanning 12 magnitudes and reaching K=18.5 at 95% completeness. The fundamental parameters of 10 young stellar systems in the region were derived through this final catalogue. (2 data files).

  1. Distraction Osteogenesis Correction of Mandibular Ramis Fracture Malunion in a Juvenile Mute Swan ( Cygnus olor ).

    PubMed

    Calvo Carrasco, Daniel; Dutton, Thomas A G; Shimizu, Naomi; Sabater, Mikel; Forbes, Neil A

    2016-03-01

    A juvenile mute swan (Cygnus olor) was presented with right lateral deviation of the mandible. Radiographs demonstrated a healed fracture of the right mandibular ramis, which had compromised osteogenesis. A corrective osteotomy was performed and an osteogenic distractor was inserted over the lateral aspect of the right mandible. Dental acrylic implants were fixed to the rhinotheca to correct rotational alignment. A pharyngostomy tube was placed to facilitate administration of nutrition and medication. Postoperative images confirmed correct alignment of the mandible in relation to the maxilla. Implants were removed and postoperative complications were not reported. This is the first report of an osteogenic distractor used to correct mandibular deviation in an avian species. Distraction osteogenesis should be considered as a valid surgical option in juvenile or adult avian patients with pathologic bone shortening.

  2. A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus superbubble.

    PubMed

    Ackermann, M; Ajello, M; Allafort, A; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Belfiore, A; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bottacini, E; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; de Angelis, A; de Palma, F; Dermer, C D; do Couto E Silva, E; Drell, P S; Dumora, D; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Fukazawa, Y; Fusco, P; Gargano, F; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Guillemot, L; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hayashi, K; Hays, E; Jóhannesson, G; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Kerr, M; Knödlseder, J; Kuss, M; Lande, J; Latronico, L; Lee, S-H; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Martin, P; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Naumann-Godo, M; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Okumura, A; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Parent, D; Pesce-Rollins, M; Pierbattista, M; Piron, F; Pohl, M; Prokhorov, D; Rainò, S; Rando, R; Razzano, M; Reposeur, T; Ritz, S; Parkinson, P M Saz; Sgrò, C; Siskind, E J; Smith, P D; Spinelli, P; Strong, A W; Takahashi, H; Tanaka, T; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Troja, E; Uchiyama, Y; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Yang, Z; Zimmer, S; Bontemps, S

    2011-11-25

    The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shockwaves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-gigaelectronvolt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population. PMID:22116880

  3. The broad-band X-ray spectrum of Cygnus X-2

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.

    1983-01-01

    Cygnus X-2 was observed with the broad-band X-ray spectroscopy experiment, HEAO 1 A-2, in the energy range 0.4-18 keV for four intervals of approximately 31 s over the course of 5 days in 1977. The spectra can be adequately represented by single-temperature thermal bremmstrahlung continua with temperatures ranging from 3.7 x 10 to the 7th K to 6.4 x 10 to the 7th K. An examination of the spectra and the spectra-luminosity relationship effectively rules out one degenerate dwarf model for the X-ray emission. The far-UV continuum emission could be dominated by this continuum component during X-ray high states, an effect which would be detected in optical UV line observations. A Comptonized X-ray cloud around a neutron star remains a viable model for the observed X-ray spectra.

  4. Can Charge Exchange Explain Anomalous Soft X-Ray Emission in the Cygnus Loop?

    NASA Astrophysics Data System (ADS)

    Cumbee, R. S.; Henley, D. B.; Stancil, P. C.; Shelton, R. L.; Nolte, J. L.; Wu, Y.; Schultz, D. R.

    2014-06-01

    Recent X-ray studies have shown that supernova shock models are unable to satisfactorily explain X-ray emission in the rim of the Cygnus Loop. In an attempt to account for this "anomalously" enhanced X-ray flux, we fit the region with a model including theoretical charge exchange (CX) data along with shock and background X-ray models. The model includes the CX collisions of O8 +, O7 +, N7 +, N6 +, C6 +, and C5 + with H with an energy of 1 keV u-1 (438 km s-1). The observations reveal a strong emission feature near 0.7 keV that cannot fully be accounted for by a shock model, nor the current CX data. Inclusion of CX, specifically O7 + + H, does provide for a statistically significant improvement over a pure shock model.

  5. BROADBAND EMISSION SPECTRA FROM THE CYGNUS X-3 JET IN THE SOFT SPECTRAL STATE

    SciTech Connect

    Zhang, Jian-Fu; Lu, Ju-Fu E-mail: lujf@xmu.edu.cn

    2015-02-01

    In order to understand the main observational characteristics of the Galactic X-ray binary Cygnus X-3, we propose a radiation model in which high-energy electrons accelerate in the dissipation zone of a jet and produce nonthermal broadband emissions. Broadband spectral energy distributions are computed to compare the AGILE and Fermi LAT data with the multi-band data during soft X-ray spectral states. By fitting observations at different locations of the jet, we find that the emission region is rather compact and should be located at a distance of about one orbital radius. Our results can explain the current multi-frequency observations and also predict the TeV band emission. The model could be tested by a polarization measurement at IR band, and/or by a correlation study between the GeV and TeV bands once very-high-energy observations are available.

  6. A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus superbubble.

    PubMed

    Ackermann, M; Ajello, M; Allafort, A; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Belfiore, A; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bottacini, E; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; de Angelis, A; de Palma, F; Dermer, C D; do Couto E Silva, E; Drell, P S; Dumora, D; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Fukazawa, Y; Fusco, P; Gargano, F; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Guillemot, L; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hayashi, K; Hays, E; Jóhannesson, G; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Kerr, M; Knödlseder, J; Kuss, M; Lande, J; Latronico, L; Lee, S-H; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Martin, P; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Naumann-Godo, M; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Okumura, A; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Parent, D; Pesce-Rollins, M; Pierbattista, M; Piron, F; Pohl, M; Prokhorov, D; Rainò, S; Rando, R; Razzano, M; Reposeur, T; Ritz, S; Parkinson, P M Saz; Sgrò, C; Siskind, E J; Smith, P D; Spinelli, P; Strong, A W; Takahashi, H; Tanaka, T; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Troja, E; Uchiyama, Y; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Yang, Z; Zimmer, S; Bontemps, S

    2011-11-25

    The origin of Galactic cosmic rays is a century-long puzzle. Indirect evidence points to their acceleration by supernova shockwaves, but we know little of their escape from the shock and their evolution through the turbulent medium surrounding massive stars. Gamma rays can probe their spreading through the ambient gas and radiation fields. The Fermi Large Area Telescope (LAT) has observed the star-forming region of Cygnus X. The 1- to 100-gigaelectronvolt images reveal a 50-parsec-wide cocoon of freshly accelerated cosmic rays that flood the cavities carved by the stellar winds and ionization fronts from young stellar clusters. It provides an example to study the youth of cosmic rays in a superbubble environment before they merge into the older Galactic population.

  7. Polarized gamma-ray emission from the galactic black hole Cygnus X-1.

    PubMed

    Laurent, P; Rodriguez, J; Wilms, J; Cadolle Bel, M; Pottschmidt, K; Grinberg, V

    2011-04-22

    Because of their inherently high flux allowing the detection of clear signals, black hole x-ray binaries are interesting candidates for polarization studies, even if no polarization signals have been observed from them before. Such measurements would provide further detailed insight into these sources' emission mechanisms. We measured the polarization of the gamma-ray emission from the black hole binary system Cygnus X-1 with the International Gamma-Ray Astrophysics Laboratory Imager on Board the Integral Satellite (INTEGRAL/IBIS) telescope. Spectral modeling of the data reveals two emission mechanisms: The 250- to 400-keV (kilo-electron volt) data are consistent with emission dominated by Compton scattering on thermal electrons and are weakly polarized. The second spectral component seen in the 400-keV to 2-MeV band is by contrast strongly polarized, revealing that the MeV emission is probably related to the jet first detected in the radio band. PMID:21436402

  8. Anatomy of a cosmic-ray neutrino source and the Cygnus X-3 system

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; Harding, A. K.; Barnard, J. J.

    1985-01-01

    The effects of an intense beam of ultra-high energy cosmic rays from a compact object in the Cygnus X-3 binary system hitting the companion star, and of the subsequent production of secondary neutrinos, are examined. A maximum allowable beam luminosity of about 10 to the 42nd erg/s is found for a system containing a 1-10 solar mass main sequence target star. The proton beam must heat a relatively small area of the target star to satisfy observational constraints on the resulting stellar wind. With such a model, the neutrino to gamma-ray flux ratio of about 1000 can result from a combination of gamma-ray absorption and a large neutrino to gamma-ray duty cycle ratio. It is found that the high density of the atmosphere resulting from compression by the beam leads to pion cascading and a neutrino spectrum peaking at 1-10 GeV energies.

  9. Using Monte-Carlo Simulations to Study the Disk Structure in Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Yao, Y.; Zhang, S. N.; Zhang, X. L.; Feng, Y. X.

    2002-01-01

    As the first dynamically determined black hole X-ray binary system, Cygnus X-1 has been studied extensively. However, its broad-band spectra in hard state with BeppoSAX is still not well understood. Besides the soft excess described by the multi-color disk model (MCD), the power- law component and a broad excess feature above 10 keV (disk reflection component), there is also an additional soft component around 1 keV, whose origin is not known currently.We propose that the additional soft component is due to the thermal Comptonization process between the s oft disk photon and the warm plasma cloud just above the disk.i.e., a warm layer. We use Monte-Carlo technique t o simulate this Compton scattering process and build several table models based on our simulation results.

  10. Present and future gamma-ray probes of the Cygnus OB2 environment

    SciTech Connect

    Anchordoqui, Luis A.; Goldberg, Haim; Moore, Russell D.; Palomares-Ruiz, Sergio; Torres, Diego F.; Weiler, Thomas J.

    2009-11-15

    The MAGIC Collaboration has provided new observational data pertaining to the TeV J2032+4130 gamma-ray source (within the Cygnus OB2 region), for energies E{sub {gamma}}>400 GeV. It is then appropriate to update the impact of these data on gamma-ray production mechanisms in stellar associations. We consider two mechanisms of gamma-ray emission, pion production and decay (PION) and photoexcitation of high-energy nuclei followed by prompt photoemission from the daughter nuclei (A*). We find that while the data can be accommodated with either scenario, the A* features a spectral bump, corresponding to the threshold for exciting the giant dipole resonance, which can serve to discriminate between them. We comment on neutrino emission and detection from the region if the PION and/or A* processes are operative. We also touch on the implications for this analysis of future Fermi and Cerenkov Telescope array data.

  11. Optical and X-Ray Observations of the Western Edge of the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    Levenson, N. A.; Graham, J. R.; Hester, J. J.; Petre, R.; Raymond, J. C.

    1994-12-01

    The western edge of the Cygnus Loop supernova remnant provides an important opportunity to study blast wave--interstellar cloud interactions. On the western edge of the Loop is an extensive coherent network of bright optical filaments from fast radiative shocks. This region is unique within the Cygnus Loop, because the remnant appears to be running into a large molecular cloud in this direction. To study this interaction we have obtained deep wide-field optical line images and X-ray observations with the ROSAT High Resolution Imager. The optical data show a variety of shocks, including non-radiative Balmer-line filaments, incomplete shocks, and shocks with complete cooling and recombination zones. The ROSAT-HRI data show bright, sharply limb-brightened X-rays confined behind the edge of the shock front delineated by the optical filaments. The Einstein-IPC data at this location has been interpreted as an enhancement due to thermal evaporation (Charles et al. 1985). Comparison of the optical and X-ray data sugests that the western limb geometry is simple. If there is evaporation, it must occur across a surface defined by a radiative shock, which contains very strong, highly ordered magnetic fields aligned in the plane of the shock. An alternative explanation for the coincidence of the bright X-rays and the radiative filaments is that compression of the post-blast wave gas by a reverse shock results in increased brightness. In either case, because of the simple geometry in this region, the X-ray emission behind the blast wave offers perhaps the clearest evidence of the structure of the post-blast wave medium in any middle-aged remnant. Charles, P. A., Kahn, S. M., and McKee, C. F. 1985 ApJ 295 456

  12. OPTICAL PHOTOMETRIC GTC/OSIRIS OBSERVATIONS OF THE YOUNG MASSIVE ASSOCIATION CYGNUS OB2

    SciTech Connect

    Guarcello, M. G.; Wright, N. J.; Drake, J. J.; Aldcroft, T.; Kashyap, V. L.; Garcia-Alvarez, D.; Drew, J. E.

    2012-10-15

    In order to fully understand the gravitational collapse of molecular clouds, the star formation process, and the evolution of circumstellar disks, these phenomena must be studied in different Galactic environments with a range of stellar contents and positions in the Galaxy. The young massive association Cygnus OB2, in the Cygnus-X region, is a unique target to study how star formation and the evolution of circumstellar disks proceed in the presence of a large number of massive stars. We present a catalog obtained with recent optical observations in the r, i, z filters with OSIRIS, mounted on the 10.4 m Gran Telescopio CANARIAS telescope, which is the deepest optical catalog of Cyg OB2 to date. The catalog consists of 64,157 sources down to M = 0.15 M{sub Sun} at the adopted distance and age of Cyg OB2. A total of 38,300 sources have good photometry in all three bands. We combined the optical catalog with existing X-ray data of this region, in order to define the cluster locus in the optical diagrams. The cluster locus in the r - i versus i - z diagram is compatible with an extinction of the optically selected cluster members in the 2.64{sup m} < A{sub V} < 5.57{sup m} range. We derive an extinction map of the region, finding a median value of A{sub V} = 4.33{sup m} in the center of the association, decreasing toward the northwest. In the color-magnitude diagrams, the shape of the distribution of main-sequence stars is compatible with the presence of an obscuring cloud in the foreground {approx}850 {+-} 25 pc from the Sun.

  13. EPISODIC TRANSIENT GAMMA-RAY EMISSION FROM THE MICROQUASAR CYGNUS X-1

    SciTech Connect

    Sabatini, S.; Tavani, M.; Vittorini, V.; Piano, G.; Del Monte, E.; Feroci, M.; Argan, A.; D'Ammando, F.; Costa, E.; De Paris, G.; Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Di Cocco, G.; Barbiellini, G.; Caraveo, P.; Chen, A. W.

    2010-03-20

    Cygnus X-1 (Cyg X-1) is the archetypal black hole binary system in our Galaxy. We report the main results of an extensive search for transient gamma-ray emission from Cygnus X-1 carried out in the energy range 100 MeV-3 GeV by the AGILE satellite, during the period 2007 July-2009 October. The total exposure time is about 300 days, during which the source was in the 'hard' X-ray spectral state. We divided the observing intervals in 2-4 week periods, and searched for transient and persistent emission. We report an episode of significant transient gamma-ray emission detected on 2009 October 16 in a position compatible with Cyg X-1 optical position. This episode, which occurred during a hard spectral state of Cyg X-1, shows that a 1-2 day time variable emission above 100 MeV can be produced during hard spectral states, having important theoretical implications for current Comptonization models for Cyg X-1 and other microquasars. Except for this one short timescale episode, no significant gamma-ray emission was detected by AGILE. By integrating all available data, we obtain a 2{sigma} upper limit for the total integrated flux of F {sub {gamma}}{sub ,U.L.} = 3 x 10{sup -8} ph cm{sup -2} s{sup -1} in the energy range 100 MeV-3 GeV. We then clearly establish the existence of a spectral cutoff in the energy range 1-100 MeV that applies to the typical hard state outside the flaring period and that confirms the historically known spectral cutoff above 1 MeV.

  14. Discovery of carbon radio recombination lines in absorption towards Cygnus A

    NASA Astrophysics Data System (ADS)

    Oonk, J. B. R.; van Weeren, R. J.; Salgado, F.; Morabito, L. K.; Tielens, A. G. G. M.; Rottgering, H. J. A.; Asgekar, A.; White, G. J.; Alexov, A.; Anderson, J.; Avruch, I. M.; Batejat, F.; Beck, R.; Bell, M. E.; van Bemmel, I.; Bentum, M. J.; Bernardi, G.; Best, P.; Bonafede, A.; Breitling, F.; Brentjens, M.; Broderick, J.; Brüggen, M.; Butcher, H. R.; Ciardi, B.; Conway, J. E.; Corstanje, A.; de Gasperin, F.; de Geus, E.; de Vos, M.; Duscha, S.; Eislöffel, J.; Engels, D.; van Enst, J.; Falcke, H.; Fallows, R. A.; Fender, R.; Ferrari, C.; Frieswijk, W.; Garrett, M. A.; Grießmeier, J.; Hamaker, J. P.; Hassall, T. E.; Heald, G.; Hessels, J. W. T.; Hoeft, M.; Horneffer, A.; van der Horst, A.; Iacobelli, M.; Jackson, N. J.; Juette, E.; Karastergiou, A.; Klijn, W.; Kohler, J.; Kondratiev, V. I.; Kramer, M.; Kuniyoshi, M.; Kuper, G.; van Leeuwen, J.; Maat, P.; Macario, G.; Mann, G.; Markoff, S.; McKean, J. P.; Mevius, M.; Miller-Jones, J. C. A.; Mol, J. D.; Mulcahy, D. D.; Munk, H.; Norden, M. J.; Orru, E.; Paas, H.; Pandey-Pommier, M.; Pandey, V. N.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Scaife, A. M. M.; Schoenmakers, A.; Schwarz, D.; Shulevski, A.; Sluman, J.; Smirnov, O.; Sobey, C.; Stappers, B. W.; Steinmetz, M.; Swinbank, J.; Tagger, M.; Tang, Y.; Tasse, C.; Veen, S. ter; Thoudam, S.; Toribio, C.; van Nieuwpoort, R.; Vermeulen, R.; Vocks, C.; Vogt, C.; Wijers, R. A. M. J.; Wise, M. W.; Wucknitz, O.; Yatawatta, S.; Zarka, P.; Zensus, A.

    2014-02-01

    We present the first detection of carbon radio recombination line absorption along the line of sight to Cygnus A. The observations were carried out with the Low Frequency Array in the 33-57 MHz range. These low-frequency radio observations provide us with a new line of sight to study the diffuse, neutral gas in our Galaxy. To our knowledge this is the first time that foreground Milky Way recombination line absorption has been observed against a bright extragalactic background source. By stacking 48 carbon α lines in the observed frequency range we detect carbon absorption with a signal-to-noise ratio of about 5. The average carbon absorption has a peak optical depth of 2 × 10-4, a line width of 10 km s-1 and a velocity of +4 km s-1 with respect to the local standard of rest. The associated gas is found to have an electron temperature Te ˜ 110 K and density ne ˜ 0.06 cm-3. These properties imply that the observed carbon α absorption likely arises in the cold neutral medium of the Orion arm of the Milky Way. Hydrogen and helium lines were not detected to a 3σ peak optical depth limit of 1.5 × 10-4 for a 4 km s-1 channel width. Radio recombination lines associated with Cygnus A itself were also searched for, but are not detected. We set a 3σ upper limit of 1.5 × 10-4 for the peak optical depth of these lines for a 4 km s-1 channel width.

  15. UNDERSTANDING COMPACT OBJECT FORMATION AND NATAL KICKS. III. THE CASE OF CYGNUS X-1

    SciTech Connect

    Wong, Tsing-Wai; Valsecchi, Francesca; Kalogera, Vassiliki; Fragos, Tassos E-mail: francesca@u.northwestern.edu E-mail: tfragos@cfa.harvard.edu

    2012-03-10

    In recent years, accurate observational constraints have become available for an increasing number of Galactic X-ray binaries (XRBs). Together with proper-motion measurements, we could reconstruct the full evolutionary history of XRBs back to the time of compact object formation. In this paper, we present the first study of the persistent X-ray source Cygnus X-1 that takes into account all available observational constraints. Our analysis accounts for three evolutionary phases: orbital evolution and motion through the Galactic potential after the formation of a black hole (BH), and binary orbital dynamics at the time of core collapse. We find that the mass of the BH immediate progenitor is 15.0-20.0 M{sub Sun }, and at the time of core collapse, the BH has potentially received a small kick velocity of {<=}77 km s{sup -1} at 95% confidence. If the BH progenitor mass is less than {approx}17 M{sub Sun }, a non-zero natal kick velocity is required to explain the currently observed properties of Cygnus X-1. Since the BH has only accreted mass from its companion's stellar wind, the negligible amount of accreted mass does not explain the observationally inferred BH spin of a{sub *} > 0.95, and the origin of this extreme BH spin must be connected to the BH formation itself. Right after the BH formation, we find that the BH companion is a 19.8-22.6 M{sub Sun} main-sequence star, orbiting the BH at a period of 4.7-5.2 days. Furthermore, recent observations show that the BH companion is currently super-synchronized. This super-synchronism indicates that the strength of tides exerted on the BH companion should be weaker by a factor of at least two compared to the usually adopted strength.

  16. P-23 Highlights 6/10/12: Cygnus Dual Beam Radiographic Facility Refurbishment completed at U1A tunnel in Nevada NNSS meeting Level 2 milestone

    SciTech Connect

    Deyoung, Anemarie; Smith, John R.

    2012-05-03

    A moratorium was placed on U.S. underground nuclear testing in 1992. In response, the Stockpile Stewardship Program was created to maintain readiness of the existing nuclear inventory through several efforts such as computer modeling, material analysis, and subcritical nuclear experiments (SCEs). As in the underground test era, the Nevada National Security Site (NNSS), formerly the Nevada Test Site, provides a safe and secure environment for SCEs by the nature of its isolated and secure facilities. A major tool for SCE diagnosis installed in the 05 drift laboratory is a high energy x-ray source used for time resolved imaging. This tool consists of two identical sources (Cygnus 1 and Cygnus 2) and is called the Cygnus Dual Beam Radiographic Facility (Figs. 2-6). Each Cygnus machine has 5 major elements: Marx Generator, Pulse Forming Line (PFL), Coaxial Transmission Line (CTL), 3-cell Inductive Voltage Adder (IVA), and Rod Pinch Diode. Each machine is independently triggered and may be fired in separate tests (staggered mode), or in a single test where there is submicrosecond separation between the pulses (dual mode). Cygnus must operate as a single shot machine since on each pulse the diode electrodes are destroyed. The diode is vented to atmosphere, cleaned, and new electrodes are inserted for each shot. There is normally two shots per day on each machine. Since its installation in 2003, Cygnus has participated in: 4 Subcritical Experiments (Armando, Bacchus, Barolo A, and Barolo B), a 12 shot plutonium physics series (Thermos), and 2 plutonium step wedge calibration series (2005, 2011), resulting in well over 1000 shots. Currently the Facility is in preparation for 2 SCEs scheduled for this calendar year - Castor and Pollux. Cygnus has performed well during 8 years of operations at NNSS. Many improvements in operations and performance have been implemented during this time. Throughout its service at U1a, major maintenance and replacement of many hardware items

  17. H{sub 2}D{sup +} IN THE HIGH-MASS STAR-FORMING REGION CYGNUS X

    SciTech Connect

    Pillai, T.; Lis, D. C.; Caselli, P.; Kauffmann, J.; Zhang, Q.; Thompson, M. A.

    2012-06-01

    H{sub 2}D{sup +} is a primary ion that dominates the gas-phase chemistry of cold dense gas. Therefore, it is hailed as a unique tool in probing the earliest, prestellar phase of star formation. Observationally, its abundance and distribution is, however, just beginning to be understood in low-mass prestellar and cluster-forming cores. In high-mass star-forming regions, H{sub 2}D{sup +} has been detected only in two cores, and its spatial distribution remains unknown. Here, we present the first map of the ortho-H{sub 2}D{sup +} J{sub k{sup +},k{sup -}} = 1{sub 1,0} {yields} 1{sub 1,1} and N{sub 2}H{sup +} 4-3 transition in the DR21 filament of Cygnus X with the James Clerk Maxwell Telescope, and N{sub 2}D{sup +} 3-2 and dust continuum with the Submillimeter Array. We have discovered five very extended ({<=}34, 000 AU diameter) weak structures in H{sub 2}D{sup +} in the vicinity of, but distinctly offset from, embedded protostars. More surprisingly, the H{sub 2}D{sup +} peak is not associated with either a dust continuum or N{sub 2}D{sup +} peak. We have therefore uncovered extended massive cold dense gas that was undetected with previous molecular line and dust continuum surveys of the region. This work also shows that our picture of the structure of cores is too simplistic for cluster-forming cores and needs to be refined: neither dust continuum with existing capabilities nor emission in tracers like N{sub 2}D{sup +} can provide a complete census of the total prestellar gas in such regions. Sensitive H{sub 2}D{sup +} mapping of the entire DR21 filament is likely to discover more of such cold quiescent gas reservoirs in an otherwise active high-mass star-forming region.

  18. What is special about Cygnus X-1 - Black holes in theory and observation: X-ray observations

    NASA Technical Reports Server (NTRS)

    Boldt, E.; Holt, S.; Rothschild, R.; Serlemitsos, P.

    1975-01-01

    Of the eight X-ray sources now known which may be associated with binary stellar systems, Cygnus X-1 is the most likely candidate for being a black hole. The X-ray evidence from several experiments is reviewed, with special emphasis on those characteristics which appear to distinguish Cygnus X-1 from other compact X-ray emitting objects. Data are examined within the context of a model in which millisecond bursts (Rothschild et al., 1974) are superposed on shot-noise fluctuations (Terrell, 1972) arising from 'events' of durations on the order of a second. Possible spectral-temporal correlations are investigated which indicate new measurements that need to be made in future experiments.

  19. A Multiwavelength Study of Cygnus X-1: The First Mid-infrared Spectroscopic Detection of Compact Jets

    NASA Astrophysics Data System (ADS)

    Rahoui, Farid; Lee, Julia C.; Heinz, Sebastian; Hines, Dean C.; Pottschmidt, Katja; Wilms, Jörn; Grinberg, Victoria

    2011-07-01

    We report on a Spitzer/InfraRed Spectrograph (mid-infrared), RXTE/PCA+HEXTE (X-ray), and Ryle (radio) simultaneous multiwavelength study of the microquasar Cygnus X-1, which aimed at an investigation of the origin of its mid-infrared emission. Compact jets were present in two out of three observations, and we show that they strongly contribute to the mid-infrared continuum. During the first observation, we detect the spectral break—where the transition from the optically thick to the optically thin regime takes place—at about 2.9 × 1013 Hz. We then show that the jet's optically thin synchrotron emission accounts for Cygnus X-1's emission beyond 400 keV, although it cannot alone explain its 3-200 keV continuum. A compact jet was also present during the second observation, but we do not detect the break, since it has likely shifted to higher frequencies. In contrast, the compact jet was absent during the last observation, and we show that the 5-30 μm mid-infrared continuum of Cygnus X-1 stems from the blue supergiant companion star HD 226868. Indeed, the emission can then be understood as the combination of the photospheric Rayleigh-Jeans tail and the bremsstrahlung from the expanding stellar wind. Moreover, the stellar wind is found to be clumpy, with a filling factor f ∞ ≈ 0.09-0.10. Its bremsstrahlung emission is likely anti-correlated to the soft X-ray emission, suggesting an anti-correlation between the mass-loss and mass-accretion rates. Nevertheless, we do not detect any mid-infrared spectroscopic evidence of interaction between the jets and Cygnus X-1's environment and/or the companion star's stellar wind.

  20. A MULTIWAVELENGTH STUDY OF CYGNUS X-1: THE FIRST MID-INFRARED SPECTROSCOPIC DETECTION OF COMPACT JETS

    SciTech Connect

    Rahoui, Farid; Lee, Julia C.; Heinz, Sebastian; Hines, Dean C.; Pottschmidt, Katja; Wilms, Joern; Grinberg, Victoria E-mail: jclee@cfa.harvard.edu E-mail: hines@stsci.edu E-mail: joern.wilms@sternwarte.uni-erlangen.de

    2011-07-20

    We report on a Spitzer/InfraRed Spectrograph (mid-infrared), RXTE/PCA+HEXTE (X-ray), and Ryle (radio) simultaneous multiwavelength study of the microquasar Cygnus X-1, which aimed at an investigation of the origin of its mid-infrared emission. Compact jets were present in two out of three observations, and we show that they strongly contribute to the mid-infrared continuum. During the first observation, we detect the spectral break-where the transition from the optically thick to the optically thin regime takes place-at about 2.9 x 10{sup 13} Hz. We then show that the jet's optically thin synchrotron emission accounts for Cygnus X-1's emission beyond 400 keV, although it cannot alone explain its 3-200 keV continuum. A compact jet was also present during the second observation, but we do not detect the break, since it has likely shifted to higher frequencies. In contrast, the compact jet was absent during the last observation, and we show that the 5-30 {mu}m mid-infrared continuum of Cygnus X-1 stems from the blue supergiant companion star HD 226868. Indeed, the emission can then be understood as the combination of the photospheric Rayleigh-Jeans tail and the bremsstrahlung from the expanding stellar wind. Moreover, the stellar wind is found to be clumpy, with a filling factor f{sub {infinity}} {approx} 0.09-0.10. Its bremsstrahlung emission is likely anti-correlated to the soft X-ray emission, suggesting an anti-correlation between the mass-loss and mass-accretion rates. Nevertheless, we do not detect any mid-infrared spectroscopic evidence of interaction between the jets and Cygnus X-1's environment and/or the companion star's stellar wind.

  1. A Multiwavelength Study of Cygnus X-1: The First Mid-Infrared Spectroscopic Detection of Compact Jets

    NASA Technical Reports Server (NTRS)

    Rahoui, Farid; Lee, Julia C.; Heinz, Sebastian; Hines, Dean C.; Pottschmidt, Katja; Wilms, Joern

    2011-01-01

    We report on a Spitzer/IRS (mid-infrared), RXTE /PCA+HEXTE (X-ray), and Ryle (radio) simultaneous multi-wavelength study of the micro quasar Cygnus X-I, which aimed at an investigation of the origin of its mid-infrared emission. Compact jets were present in two out of three observations, and we show that they strongly contribute to the mid-infrared continuum. During the first observation, we detect the spectral break - where the transition from the optically thick to the optically thin regime takes place - at about 2.9 x 10(exp 13) Hz. We then show that the jet's optically thin synchrotron emission accounts for the Cygnus X-1's emission beyond 400 keY, although it cannot alone explain its 3-200 keV continuum. A compact jet was also present during the second observation, but we do not detect the break, since it has likely shifted to higher frequencies. In contrast, the compact jet was absent during the last observation, and we show that the 5-30 micron mid-infrared continuum of Cygnus X-I stems from the blue supergiant companion star HD 226868. Indeed, the emission can then be understood as the combination of the photospheric Raleigh-Jeans tail and the bremsstrahlung from the expanding stellar wind. Moreover, the stellar wind is found to be clumpy, with a filling factor f(sub infinity) approx.= 0.09-0.10. Its bremsstrahlung emission is likely anti-correlated to the soft X-ray emission, suggesting an anticorrelation between the mass-loss and mass-accretion rates. Nevertheless, we do not detect any mid-infrared spectroscopic evidence of interaction between the jets and the Cygnus X-1's environment and/or companion star's stellar wind.

  2. Leveraging High Resolution Spectra to Understand the Disk and Relativistic Iron Line of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Nowak, M.; Wilms, J.; Pottschmidt, K.; Grinberg, V.; Schulz, N.; Corrales, L.

    2016-06-01

    In April 2008 we conducted an observation of the black hole candidate Cygnus X-1 that was performed simultaneously with every X-ray and gamma-ray satellite flying at that time, including Chandra-HETG. The HETG spectra are crucial for modeling the ionized absorbtion from the "focused-wind" of the secondary, which is present and must be accounted for in all of our spectra. These features, however, are unresolved in the non-gratings instruments (e.g., RXTE, Suzaku, Swift, XMM-EPIC, INTEGRAL). Similarly, we must account for differences in spatial resolution. The X-ray scattering dust halo, which is usually ignored in most analyses, is spatially resolved in the Chandra and XMM-Newton spectra, but is unresolved in the other instruments. Thus one must account for dust scattering loss in the high spatial resolution spectra, and the scattering back into our line of site for the low resolution spectra. In this work, we attempt to arrive at a joint model for these spectra, and further comment on the cross calibration of each of the X-ray instruments participating in this campaign.

  3. Aerogel Cherenkov detector for characterizing the intense flash x-ray source, Cygnus, spectrum

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Herrmann, H. W.; McEvoy, A. M.; Young, C. S.; Hamilton, C.; Schwellenbach, D. D.; Malone, R. M.; Kaufman, M. I.; Smith, A. S.

    2016-11-01

    An aerogel Cherenkov detector is proposed to measure the X-ray energy spectrum from the Cygnus—intense flash X-ray source operated at the Nevada National Security Site. An array of aerogels set at a variety of thresholds between 1 and 3 MeV will be adequate to map out the bremsstrahlung X-ray production of the Cygnus, where the maximum energy of the spectrum is normally around 2.5 MeV. In addition to the Cherenkov radiation from aerogels, one possible competing light-production mechanism is optical transition radiation (OTR), which may be significant in aerogels due to the large number of transitions from SiO2 clusters to vacuum voids. To examine whether OTR is a problem, four aerogel samples were tested using a mono-energetic electron beam (varied in the range of 1-3 MeV) at NSTec Los Alamos Operations. It was demonstrated that aerogels can be used as a Cherenkov medium, where the rate of the light production is about two orders magnitude higher when the electron beam energy is above threshold.

  4. Soft X-Ray Spectroscopy of the Cygnus Loop Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Oakley, Phil; McEntaffer, Randall; Cash, Webster

    2013-03-01

    We present the results of a suborbital rocket flight whose scientific target was the Cygnus Loop Supernova Remnant. The payload consists of wire grid collimators, off-plane grating arrays, and gaseous electron multiplier (GEM) detectors. The system is designed for spectral measurements in the 17-107 Å bandpass with a resolution up to ~60 (λ/Δλ). The Extended X-ray Off-plane Spectrometer (EXOS) was launched on a Terrier-Black Brant rocket on 2009 November 13 from White Sands Missile Range and obtained 340 s of useable scientific data. The X-ray emission is dominated by O VII and O VIII, including the He-like O VII triplet at ~22 Å. Another emission feature at ~45 Å is composed primarily of Si XI and Si XII. The best-fit model to this spectrum is an equilibrium plasma model at a temperature of log(T) = 6.4 (0.23 keV).

  5. Acute toxicity and sublethal effects of white phosphorus in mute swans, Cygnus olor

    USGS Publications Warehouse

    Sparling, D.W.; Day, D.; Klein, P.

    1999-01-01

    Among the waterfowl affected by white phosphorus (P4) at a military base in Alaska are tundra (Cygnus columbianus) and trumpeter (C. buccinator) swans. To estimate the toxicity of P4 to swans and compare the toxic effects to those of mallards (Anas platyrhynchos), we dosed 30 juvenile mute swans (C. olor) with 0 to 5.28 mg P4 /kg body weight. The estimated LD50 was 3.65 mg/kg (95% CI: 1.40 to 4.68 mg/kg). However, many of the swans still had P4 in their gizzards after dying, as determined by 'smoking gizzards', and a lower LD50 might be calculated if all of the P4 had passed into the small intestines. We attribute the retention of P4 in swans to the presence of coarse sandlike particles of grit which were of similar size as the P4 pellets. Most swans took 1 to 4.5 days to die in contrast to the few hours normally required in mallards and death appeared to related more to liver dysfunction than to hemolysis. White phosphorus affected several plasma constituents, most notably elevated aspartate amiontransferase, blood urea nitrogen, lactate dehydrogenase, and alanine aminotransferase.

  6. Complete mitochondrial genome of Tundra swan Cygnus columbianus jankowskii (Anseriformes: Anatidae).

    PubMed

    Wang, Jinghua; Liu, Gang; Zhou, Lizhi; Qing, Hui; Li, Lunyue; Li, Bo; Zhang, Lili

    2016-01-01

    Cygnus columbianus jankowskii is a subspecies of Tundra swan, which breeds in eastern Russia and northeast China, wintering in the middle and lower reaches of the Yangtze River. In this study, we used PCR-based method to obtain the complete mtDNA of this subspecies. The arrangement pattern of the complete mtDNA is identical with typical bird species, which is the shortest (16,723 bp) in three subspecies. The length of the PCGs is same except ND2, ND3 and ND6, and the initiation/termination codons are all same with other subspecies. The length of 12S rRNA and 16S rRNA is same with C. c. columbianus, but different from C. c. bewickii. The length and structure of all tRNAs are the same with other subspecies except for tRNA(Ile), tRNA(leu(CUN)) and tRNA(ser(AGY)). The control region is located between tRNA(Phe) and tRNA(Glu), but the length is different with others.

  7. Cygnus X-2: The Descendant of an Intermediate-Mass X-Ray Binary

    NASA Astrophysics Data System (ADS)

    Podsiadlowski, Ph.; Rappaport, S.

    2000-02-01

    The X-ray binary Cygnus X-2 (Cyg X-2) has recently been shown to contain a secondary that is much more luminous and hotter than is appropriate for a low-mass subgiant. We present detailed binary-evolution calculations which demonstrate that the present evolutionary state of Cyg X-2 can be understood if the secondary had an initial mass of around 3.5 Msolar and started to transfer mass near the end of its main-sequence phase (or, somewhat less likely, just after leaving the main sequence, as recently suggested independently by A. R. King & H. Ritter). Most of the mass of the secondary must have been ejected from the system during an earlier rapid mass transfer phase. In the present phase, the secondary has a mass of around 0.5 Msolar with a nondegenerate helium core. It is burning hydrogen in a shell, and mass transfer is driven by the advancement of the burning shell. Cyg X-2 therefore is related to a previously little studied class of intermediate-mass X-ray binaries (IMXBs). We suggest that perhaps a significant fraction of X-ray binaries presently classified as low-mass X-ray binaries may be descendants of IMXBs and discuss some of the implications.

  8. A cocoon of freshly accelerated cosmic rays detected by Fermi in the Cygnus superbubble

    NASA Astrophysics Data System (ADS)

    Grenier, Isabelle A.; Tibaldo, Luigi; Fermi-LAT Collaboration

    2013-02-01

    Conspicuous stellar clusters, with high densities of massive stars, powerful stellar winds, and intense UV flux, have formed over the past few million years in the large molecular clouds of the Cygnus X region, 1.4 kpc away from the Sun. By capturing the gamma-ray signal of young cosmic rays spreading in the interstellar medium surrounding the clusters, the Fermi Large Area Telescope (LAT) has confirmed the long-standing hypothesis that massive-star forming regions host cosmic-ray factories. The 50-pc wide cocoon of energetic particles appears to fill the interstellar cavities carved by the stellar activity. The cocoon provides a first test case to study the impact of wind-powered turbulence on the early phases of cosmic-ray diffusion (between the sources and the Galaxy at large) and to study the acceleration potential of this type of superbubble environment for in-situ cosmic-ray production or to energize Galactic cosmic rays passing by.

  9. Near-Infrared Variability Among YSOs in the Star Forming Region Cygnus OB7

    NASA Astrophysics Data System (ADS)

    Rice, Thomas; Wolk, S. J.; Aspin, C.

    2013-01-01

    We present an analysis of near-infrared time-series photometry in J, H, and K bands for about 100 epochs of a 1 deg x 1 deg region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. From the 7 bands of near and mid-infrared photometry we identify 92 candidate disk bearing young stellar objects (YSOs). Of these, 27 are clearly Class I or earlier. Using the Wide-Field imaging CAMera (WFCAM) on the United Kingdom InfraRed Telescope (UKIRT), we were able to obtain photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J=17. We study in detail the light curves and color trajectories of 50 of these sources in the monitored field. We investigate the variability and periodicity of the YSOs and find the data are consistent with all YSOs being variable in these wavelengths on time scales of a few years. We divide the variability into four observational classes: 1) stars with periodic variability stable over long timescales, 2) variables which exhibit short-lived periodicity, 3) long-term eruptive variables, and 4) stochastic variables. Some YSO variability defies simple classification. We can explain much of the observed variability as being due to dynamic and rotational changes in the disk, including an asymmetric or changing blocking fraction, changes to the inner disk hole size as well as the accretion rate.

  10. Periodic Near-infrared Variability in the Star Formation Region Cygnus OB7

    NASA Astrophysics Data System (ADS)

    Wolk, Scott J.; Rice, T. S.; Aspin, C.

    2013-01-01

    We present an analysis of mid and near-infrared time-series photometry in J, H, and K bands for about 100 epochs of a 1 degree region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. Combined with WISE infrared colors we identify or confirm 93 disk bearing young stellar Objects (YSOs). Of these, more than 25 are Class I or earlier. Using the Wide-Field imaging CAMera (WFCAM) on the United Kingdom InfraRed Telescope (UKIRT), we were able to obtain photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J=17. We study the light curves and color trajectories of the sources in the monitored field in detail. We investigate the variability and periodicity of the YSOs and find that they divide into four observational classes: 1) stochastic variables, 2) variables which exhibit short-lived periodicity, 3) long-term eruptive variables, and 4) stars with periodic variability stable over long timescales. Some YSO variability defies simple classification. We have uncovered a population of young stars whose K-band infrared excesses vary significantly over our 2-year observation window. We describe this variability due to both dynamic and rotational changes in inner disk hole size and accretion rate.

  11. Interferometric observation of Cygnus-A discrete radiosource scintillations at Irkutsk Incoherent Scatter radar

    NASA Astrophysics Data System (ADS)

    Globa, Mariya; Vasilev, Roman; Kushnaryov, Dmitriy; Medvedev, Andrey

    2016-03-01

    We propose a new method for analysis of data from Irkutsk Incoherent Scatter Radar. The method allows us to accomplish interferometric observation of discrete cosmic radio source characteristics. In this study, we analyzed ionospheric scintillations of the radio source Cygnus-A. Observations were made in 2013 during regular radar sessions within 5-15 days for different seasons, and the effective time of observation was 15-30 minutes per day. For interferometric analysis, the properties of correlation (coherence) coefficient of two independent recording channels were used. The statistical analysis of data from independent channels allows us to construct two-dimensional histograms of radio source brightness distribution with period of 18 s and to determine parameters (the maximum position and the histogram width) representing position and angular size of radio source for each histogram. It is shown that the change of statistical characteristics does not correlate with fluctuations in power (scintillations) of the signal caused by radio wave propagation through ionospheric irregularities.

  12. On the nature of high reddening of Cygnus OB2 #12 hypergiant

    NASA Astrophysics Data System (ADS)

    Maryeva, O. V.; Chentsov, E. L.; Goranskij, V. P.; Dyachenko, V. V.; Karpov, S. V.; Malogolovets, E. V.; Rastegaev, D. A.

    2016-05-01

    To explain the nature of the high reddening (AV ≃ 10 mag) towards one of the most luminous stars in the Galaxy - Cyg OB2 #12 (B5 Ia-0), also known as MT304, we carried out spectrophotometric observations of 24 stars located in its vicinity. We included five new B-stars among the members of Cygnus OB2, and for five more photometrically selected stars we spectroscopically confirmed their membership. We constructed the map of interstellar extinction within 2.5 arcmin radius and found that interstellar extinction increases towards MT304. According to our results the most reddened OB-stars in the association after MT304 are J203240.35+411420.1 and J203239.90+411436.2, located about 15 arcsec away from it. Interstellar extinction towards these stars is about 9 mag. The increase of reddening towards MT304 suggests that the reddening excess may be caused by the circumstellar shell ejected by the star during its evolution. This shell absorbs 1 mag, but its chemical composition and temperature are unclear. We also report the detection of a second component of MT304, and discovery of an even fainter third component, based on data of speckle interferometric observations taken with the Russian 6-m telescope.

  13. Electron Energy Distributions at Relativistic Shock Sites: Observational Constraints from the Cygnus A Hotspots

    SciTech Connect

    Cheung, C.C.Teddy; Stawarz, L.; Harris, D.E.; Ostrowski, M.

    2007-10-15

    We report new detections of the hotspots in Cygnus A at 4.5 and 8.0 microns with the Spitzer Space Telescope. Together with detailed published radio observations and synchrotron self-Compton modeling of previous X-ray detections, we reconstruct the underlying electron energy spectra of the two brightest hotspots (A and D). The low-energy portion of the electron distributions have flat power-law slopes (s {approx} 1.5) up to the break energy which corresponds almost exactly to the mass ratio between protons and electrons; we argue that these features are most likely intrinsic rather than due to absorption effects. Beyond the break, the electron spectra continue to higher energies with very steep slopes s>3. Thus, there is no evidence for the 'canonical' s=2 slope expected in 1st order Fermi-type shocks within the whole observable electron energy range. We discuss the significance of these observations and the insight offered into high-energy particle acceleration processes in mildly relativistic shocks.

  14. Period change of massive binaries from combined photometric and spectroscopic data in Cygnus OB2

    NASA Astrophysics Data System (ADS)

    Laur, Jaan; Tempel, Elmo; Tuvikene, Taavi; Eenmäe, Tõnis; Kolka, Indrek

    2015-09-01

    Context. Mass loss is an important property in evolution models of massive stars. As up to 90% of the massive stars have a visual or spectroscopic companion and many of them exhibit mass exchange, mass-loss rates can be acquired through studying the period of massive binaries. Aims: Using our own photometric observations as well as archival data, we searched for variations in orbital periods of seven massive eclipsing binary systems in the Cygnus OB2 association and estimated their mass-loss rates and stellar parameters. Methods: We used a Bayesian parameter estimation method to simultaneously fit the period and period change to all available data and a stellar modelling tool to model the binary parameters from photometric and radial-velocity data. Results: Four out of the seven selected binaries show non-zero period change values at two-sigma confidence level. We also report the eclipsing nature of the star MT059 for the first time. Appendix A is available in electronic form at http://www.aanda.org

  15. Chemical abundances in the secondary star of the X-ray binary Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Suárez-Andrés, l.; González Hernández, J. I.; Israelian, G.; Rebolo, R.

    2015-05-01

    Spectroscopic data of low-mass X-ray binaries (LMXB) can provide valuable information on supernova properties. In these systems the companion star is probably close enough to be polluted by some of the matter ejected during the supernova (SN) event of the progenitor of the compact object. We present high-resolution spectra, acquired with UES@WHT, of the LMXB Cygnus X-2. We derive the stellar parameters of the companion, taking into account any possible veiling from the accretion disk surrounding the NS. We have studied the chemical abundances, including α-elements and some Fe-peak elements to search for signatures of chemical anomalies that could have been imprinted on the secondary star in the SN event. We find a super-solar Fe content in the companion star, and an abundance enhancement in most of the studied elements. Our results suggest that the secondary star may have captured a significant amount of the ejected matter during the SN explosion. We explore different explosion models to explain these abundance anomalies.

  16. SOFT X-RAY SPECTROSCOPY OF THE CYGNUS LOOP SUPERNOVA REMNANT

    SciTech Connect

    Oakley, Phil; McEntaffer, Randall; Cash, Webster

    2013-03-20

    We present the results of a suborbital rocket flight whose scientific target was the Cygnus Loop Supernova Remnant. The payload consists of wire grid collimators, off-plane grating arrays, and gaseous electron multiplier (GEM) detectors. The system is designed for spectral measurements in the 17-107 A bandpass with a resolution up to {approx}60 ({lambda}/{Delta}{lambda}). The Extended X-ray Off-plane Spectrometer (EXOS) was launched on a Terrier-Black Brant rocket on 2009 November 13 from White Sands Missile Range and obtained 340 s of useable scientific data. The X-ray emission is dominated by O VII and O VIII, including the He-like O VII triplet at {approx}22 A. Another emission feature at {approx}45 A is composed primarily of Si XI and Si XII. The best-fit model to this spectrum is an equilibrium plasma model at a temperature of log(T) = 6.4 (0.23 keV).

  17. CAN CHARGE EXCHANGE EXPLAIN ANOMALOUS SOFT X-RAY EMISSION IN THE CYGNUS LOOP?

    SciTech Connect

    Cumbee, R. S.; Henley, D. B.; Stancil, P. C.; Shelton, R. L.; Nolte, J. L.; Wu, Y.; Schultz, D. R.

    2014-06-01

    Recent X-ray studies have shown that supernova shock models are unable to satisfactorily explain X-ray emission in the rim of the Cygnus Loop. In an attempt to account for this ''anomalously'' enhanced X-ray flux, we fit the region with a model including theoretical charge exchange (CX) data along with shock and background X-ray models. The model includes the CX collisions of O{sup 8} {sup +}, O{sup 7} {sup +}, N{sup 7} {sup +}, N{sup 6} {sup +}, C{sup 6} {sup +}, and C{sup 5} {sup +} with H with an energy of 1 keV u{sup –1} (438 km s{sup –1}). The observations reveal a strong emission feature near 0.7 keV that cannot fully be accounted for by a shock model, nor the current CX data. Inclusion of CX, specifically O{sup 7} {sup +} + H, does provide for a statistically significant improvement over a pure shock model.

  18. Time Domain Studies of X-Ray Shot Noise in Cygnus X-1

    SciTech Connect

    Focke, Warren; Wai, Lawrence L.; Swank, Jean H.; /NASA, Goddard

    2005-07-27

    We investigate the variability of Cygnus X-1 in the context of shot noise models, and employ a peak detection algorithm to select individual shots. For a long observation of the low, hard state, the distribution of time intervals between shots is found to be consistent with a purely random process, contrary to previous claims in the literature. The detected shots are fit to several model templates and found to have a broad range of shapes. The fitted shots have a distribution of timescales from below 10 milliseconds to above 1 second. The coherence of the cross spectrum of light curves of these data in different energy bands is also studied. The observed high coherence implies that the transfer function between low and high energy variability is uniform. The uniformity of the transfer function implies that the observed distribution of shot widths cannot have been acquired through Compton scattering. Our results in combination with other results in the literature suggest that shot luminosities are correlated with one another. We discuss how our experimental methodology relates to non-linear models of variability.

  19. Fermi Large Area Telescope Observations of the Cygnus Loop Supernova Remnant

    SciTech Connect

    Katagiri, H.; Tibaldo, L.; Ballet, J.; Giordano, F.; Grenier, I.A.; Porter, T.A.; Roth, M.; Tibolla, O.; Uchiyama, Y.; Yamazaki, R.; /Sagamihara, Aoyama Gakuin U.

    2011-11-08

    We present an analysis of the gamma-ray measurements by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnant (SNR) Cygnus Loop (G74.0-8.5). We detect significant gamma-ray emission associated with the SNR in the energy band 0.2-100 GeV. The gamma-ray spectrum shows a break in the range 2-3 GeV. The gamma-ray luminosity is {approx} 1 x 10{sup 33} erg s{sup -1} between 1-100 GeV, much lower than those of other GeV-emitting SNRs. The morphology is best represented by a ring shape, with inner/outer radii 0{sup o}.7 {+-} 0{sup o}.1 and 1{sup o}.6 {+-} 0{sup o}.1. Given the association among X-ray rims, H{alpha} filaments and gamma-ray emission, we argue that gamma rays originate in interactions between particles accelerated in the SNR and interstellar gas or radiation fields adjacent to the shock regions. The decay of neutral pions produced in nucleon-nucleon interactions between accelerated hadrons and interstellar gas provides a reasonable explanation for the gamma-ray spectrum.

  20. THE YOUNG STELLAR POPULATION OF THE CYGNUS-X DR15 REGION

    SciTech Connect

    Rivera-Gálvez, S.; Román-Zúñiga, C. G.; Jiménez-Bailón, E.; Ybarra, J. E.; Alves, J. F.

    2015-12-15

    We present a multi-wavelength study of the young stellar population in the Cygnus-X DR15 region. We studied young stars that were forming or recently formed at and around the tip of a prominent molecular pillar and an infrared dark cloud. Using a combination of ground-based near-infrared, space-based infrared, and X-ray data, we constructed a point source catalog from which we identified 226 young stellar sources, which we classified into evolutionary classes. We studied their spatial distributions across the molecular gas structures and identified several groups that possibly belong to distinct young star clusters. We obtained samples of these groups and constructed K-band luminosity functions that we compared with those of artificial clusters, allowing us to make first order estimates of the mean ages and age spreads of the groups. We used a {sup 13}CO(1-0) map to investigate the gas kinematics at the prominent gaseous envelope of the central cluster in DR15, and we inferred that the removal of this envelope is relatively slow compared to other cluster regions, in which the gas dispersal timescale could be similar or shorter than the circumstellar disk dissipation timescale. The presence of other groups with slightly older ages, associated with much less prominent gaseous structures, may imply that the evolution of young clusters in this part of the complex proceeds in periods that last 3–5 Myr, perhaps after a slow dissipation of their dense molecular cloud birthplaces.

  1. The velocity dependence of X-ray emission due to Charge Exchange in the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    Cumbee, Renata; Lyons, David; Mullen, Patrick Dean; Shelton, Robin L.; Stancil, Phillip C.; Schultz, David R.

    2016-01-01

    The fundamental collisional process of charge exchange (CX) has been been established as a primary source of X-ray emission from the heliosphere [1], planetary exospheres [2], and supernova remnants [3,4]. In this process, X-ray emission results from the capture of an electron by a highly charged ion from a neutral atom or molecule, to form a highly-excited, high charge state ion. As the captured electron cascades down to the lowest energy level, photons are emitted, including X-rays.To provide reliable CX-induced X-ray spectral models to realistically simulate these environments, line ratios and spectra are computed using theoretical CX cross-sections obtained with the multi-channel Landau-Zener, atomic-orbital close-coupling, and classical-trajectory Monte Carlo methods for various collisional velocities relevant to astrophysics for collisions of bare and H-like C to Al ions with H, He, and H2. Using these line ratios, XSPEC models of CX emission in the northeast rim of the Cygnus Loop supernova remnant will be shown as an example with ion velocity dependence.[1] Henley, D. B. & Shelton, R. L. 2010, ApJSS, 187, 388[2] Dennerl, K. et al. 2002, A&A 386, 319[3] Katsuda, S. et al. 2011, ApJ 730 24[4] Cumbee, R. S. et al. 2014, ApJ 787 L31This work was partially supported by NASA grant NNX09AC46G.

  2. Simulation of the cygnus rod-pinch diode using the radiographic chain model

    SciTech Connect

    Kwan, Thomas Jt; Wang, Tai - Sen F; Berninger, Michael; Snell, Charles M; Lin, Yin

    2008-01-01

    The Cygnus radiographic machine is a relatively compact low-energy (<3 MV) x-ray source with some extremely desirable features for radiographic applications. These features include small spot size critical for high-spatial resolution and high dose in a low energy range. The x-ray source is based on bremsstrahlung production in a small diameter ({approx}0.75 mm) tungsten rod by a high-current ({approx}60 kA) electron beam converging at the tip of the rod. For quantitative analysis of radiographic data, it is essential to determine the bremsstrahlung spectrum accurately. We have used the radiographic chain model that self-consistently models the diode with a two-dimensional particle-in-cell code (Merlin) which links to an electron-photon Monte Carlo code to obtain the spectrum under three different situations. These are: steady state spectrum using a voltage puise of 2.5 MV, time-integrated spectrum using a time-dependent experimental voltage pulse, and inclusion of reflexing electrons at the anode in our particle-in-cell simulation. Detailed electron dynamics have been obtained in our study. Our investigations conclude that the time integrated bremsstrahlung spectrum is significantly softer than that of the steady state. In our latest simulations, we have included the effects of reflexing electrons around the anode rod and found the spectrum to be in better agreement with experimental data.

  3. Acute toxicity and sublethal effects of white phosphorus in mute swans, Cygnus olor.

    PubMed

    Sparling, D W; Day, D; Klein, P

    1999-04-01

    Among the waterfowl affected by white phosphorus (P4) at a military base in Alaska are tundra (Cygnus columbianus) and trumpeter (C. buccinator) swans. To estimate the toxicity of P4 to swans and compare the toxic effects to those of mallards (Anas platyrhynchos), we dosed 30 juvenile mute swans (C. olor) with 0 to 5.28 mg P4/kg body weight. The calculated LD50 was 3.65 mg/kg (95% CI: 1.40 to 4. 68 mg/kg). However, many of the swans still had P4 in their gizzards after dying, as determined by "smoking gizzards" and characteristic odor, and a lower LD50 might be calculated if all of the P4 had passed into the small intestines. We attribute the retention of P4 in swans to the possibility that P4 pellets were mistaken for the similarly sized grit in their gizzards. Most swans took 1 to 4.5 days to die in contrast to the few hours normally required in mallards and death appeared to be related more to liver dysfunction than to hemolysis. White phosphorus affected several plasma constituents, most notably elevated aspartate aminotransferase, blood urea nitrogen, lactate dehydrogenase, and alanine aminotransferase.

  4. Spectroscopy of the Stellar Wind in the Cygnus X-1 System

    NASA Technical Reports Server (NTRS)

    Miskovicova, Ivica; Hanke, Manfred; Wilms, Joern; Nowak, Michael A.; Pottschmidt, Katja; Schultz, Norbert

    2010-01-01

    The X-ray luminosity of black holes is produced through the accretion of material from their companion stars. Depending on the mass of the donor star, accretion of the material falling onto the black hole through the inner Lagrange point of the system or accretion by the strong stellar wind can occur. Cygnus X-1 is a high mass X-ray binary system, where the black hole is powered by accretion of the stellar wind of its supergiant companion star HDE226868. As the companion is close to filling its Roche lobe, the wind is not symmetric, but strongly focused towards the black hole. Chandra-HETGS observations allow for an investigation of this focused stellar wind, which is essential to understand the physics of the accretion flow. We compare observations at the distinct orbital phases of 0.0, 0.2, 0.5 and 0.75. These correspond to different lines of sights towards the source, allowing us to probe the structure and the dynamics of the wind.

  5. Observation of muons from Cygnus X-3 in the NUSEX experiment

    NASA Technical Reports Server (NTRS)

    Piazzoli, B. D.

    1986-01-01

    Ground based observations by means of Cerenkov light detectors and air shower arrays have established that Cyngus X-3 is a powerful source of high energy particles. The detection of a 10 to the 15th power eV signal was first reported by the Kiel experiment. Air showers with large age parameter were accepted in order to select those generated by primary gamma rays. At variance with the expectation, the muon density associated with these events was found to be surprisingly high. This puzzling result stimulated a temporal analysis of the muons recorded in Nucleon Stability Experiment (NUSEX) coming from the region around the source. A positive signal was found suggesting the presentation of this result. The analysis of the data recorded during the 2.4 years of effective working time is presented with a fine tuning of the period and the energy spectrum of the muons from the Cygnus X-3 direction derived assuming consistency between NUSEX and SOUDAN results.

  6. Zinc toxicosis in a free-flying trumpeter swan (Cygnus buccinator)

    USGS Publications Warehouse

    Carpenter, J.W.; Andrews, G.A.; Beyer, W.N.

    2004-01-01

    A trumpeter swan (Cygnus buccinator) was observed near it mill pond in Picher, Oklahoma. USA. It became weakened and emaciated after about 1 mo, was captured with little resistance, and taken into captivity for medical care. Serum chemistry results were consistent with hepatic, renal, and muscular damage. Serum zinc concentration was elevated at 11.2 parts per million (ppm). The swan was treated for suspected heavy-metal poisoning, but died overnight. Gross postmortem findings were emaciation and pectoral muscle atrophy. Histopathologic lesions in the pancreas included mild diffuse disruption of acinar architecture, severe diffuse depletion or absence of zymogen granules, occasional apoptotic bodies ics in acinar epithelial cells, and mild interstitial and capsular fibrosis. Zinc concentration in pancreas was 3,200 ppm wet weight, and was similar to that reported in the pancreases of waterfowl known to be killed by zinc toxicity. Zinc concentrations in liver (154 ppm) and kidneys (145 ppm) also were elevated. Acute tubular necrosis of the collecting tubules of the kidneys was also possibly due to zinc toxicity. To the authors' knowledge, this is the first confirmed case of zinc poisoning in a trumpeter swan associated with mining wastes..

  7. DUST DESTRUCTION IN A NON-RADIATIVE SHOCK IN THE CYGNUS LOOP SUPERNOVA REMNANT

    SciTech Connect

    Sankrit, Ravi; Gaetz, Terrance J.; Raymond, John C.; Blair, William P.; Ghavamian, Parviz; Long, Knox S.

    2010-04-01

    We present 24 {mu}m and 70 {mu}m images of a non-radiative shock in the Cygnus Loop supernova remnant, obtained with the Multiband Imaging Photometer for Spitzer on board the Spitzer Space Telescope. The post-shock region is resolved in these images. The ratio of the 70 {mu}m to the 24 {mu}m flux rises from about 14 at a distance 0.'1 behind the shock front to about 22 in a zone 0.'75 further downstream, as grains are destroyed in the hot plasma. Models of dust emission and destruction using post-shock electron temperatures between 0.15 keV and 0.30 keV and post-shock densities, n{sub H}{approx} 2.0 cm{sup -3}, predict flux ratios that match the observations. Non-thermal sputtering (i.e., sputtering due to bulk motion of the grains relative to the gas) contributes significantly to the dust destruction under these shock conditions. From the model calculations, we infer that about 35% by mass of the grains are destroyed over a 0.14 pc region behind the shock front.

  8. Possible Charge Exchange X-Ray Emission from the Cygnus Loop detected with Suzaku

    NASA Astrophysics Data System (ADS)

    Katsuda, Satoru; Tsunemi, Hiroshi; Mori, Koji; Uchida, Hiroyuki; Kosugi, Hiroko; Kimura, Masashi; Petre, Robert; Hwang, Una; Hewitt, John

    We present results of a spatially-resolved X-ray spectral analysis of nearly the entire rim of the Cygnus Loop using Suzaku (21 pointings) and XMM-Newton (1 pointing). We find that some of the spectra show a bump at ˜0.7 keV as a "shoulder" of the lines at ˜0.66 keV which is a combination of O H Lyα and O Heβ. The regions showing the "shoulder" is confined within narrow (< a few arcmin) regions behind the shock at position angles of 0-40, 110-160, and 270-330 degrees measured from north over east. Around the rim, the position angles where the X-ray excess is present correspond to relatively weak radio emission as well as optical emission from non-radiative Hα filaments. While other possibilities (e.g., Fe L emission) cannot be fully excluded, these correlations lead us to consider that the "shoulder" may be O Heγ + δ + etc lines produced by charge exchange between H-like O ions and neutral H. Whatever its origin, the "shoulder" significantly affects the spectral analysis; the best-fit parameters strongly depend on whether or not we include the "shoulder" in the spectral fitting. We will discuss this issue in terms of our previous results of our spectral analysis for the rim regions.

  9. X-ray emission from charge exchange in the Cygnus Loop SNR

    NASA Astrophysics Data System (ADS)

    Roberts, Shawn R.; Wang, Q. Daniel

    2015-05-01

    The Cygnus Loop has been the focus of substantial debate concerning the contribution of charge exchange (CX) to supernova remnant (SNR) X-ray emission. We take advantage of a distinct feature of CX, enhanced Kα forbidden line emission, and employ the energy centroid of the O VII Kα triplet as a diagnostic. Based on X-ray spectra extracted from an extensive set of Suzaku observations, we measure the energy centroid shifts of the triplet on and off the shock rim of the remnant. We find that enhanced forbidden to resonance line emission exists throughout much of the rim and this enhancement azimuthally correlates with non-radiative Hα filaments, a tracer of strong neutral-plasma interaction in the optical. We also show that alternative mechanisms cannot explain the observed enhancement. These results demonstrate the need to model the CX contribution to the X-ray emission of SNRs, particularly for shocks propagating in a partially neutral medium. Such modelling may be critically important to the correct measurements of the ionization, thermal, and chemical properties of SNRs.

  10. Multi-Satellite Observations of Cygnus X-1 to Study the Focused Wind and Absorption Dips

    NASA Technical Reports Server (NTRS)

    Hanke, Manfred; Wilms, Joern; Boeck, Moritz; Nowak, Michael A.; Schultz, Norbert S.; Pottschmidt, Katja; Lee, Julia C.

    2008-01-01

    High-mass X-ray binary systems are powered by the stellar wind of their donor stars. The X-ray state of Cygnus X-1 is correlated with the properties of the wind which defines the environment of mass accretion. Chandra-HETGS observations close to orbital phase 0 allow for an analysis of the photoionzed stellar wind at high resolution, but because of the strong variability due to soft X-ray absorption dips, simultaneous multi-satellite observations are required to track and understand the continuum, too. Besides an earlier joint Chandra and RXTE observation, we present first results from a recent campaign which represents the best broad-band spectrum of Cyg X-1 ever achieved: On 2008 April 18/19 we observed this source with XMM-Newton, Chandra, Suzaku, RXTE, INTEGRAL, Swift, and AGILE in X- and gamma-rays, as well as with VLA in the radio. After superior conjunction of the black hole, we detect soft X-ray absorption dips likely due to clumps in the focused wind covering greater than or equal to 95% of the X-ray source, with column densities likely to be of several 10(exp 23) cm(exp -2), which also affect photon energies above 20 keV via Compton scattering.

  11. Accretion and outflow in the proplyd-like objects near Cygnus OB2

    SciTech Connect

    Guarcello, M. G.; Drake, J. J.; Wright, N. J.; García-Alvarez, D.; Kraemer, K. E.

    2014-09-20

    Cygnus OB2 is the most massive association within 2 kpc from the Sun, hosting hundreds of massive stars, thousands of young low mass members, and some sights of active star formation in the surrounding cloud. Recently, 10 photoevaporating proplyd-like objects with tadpole-shaped morphology were discovered in the outskirts of the OB association, approximately 6-14 pc away from its center. The classification of these objects is ambiguous, being either evaporating residuals of the parental cloud that are hosting a protostar inside or disk-bearing stars with an evaporating disk, such as the evaporating proplyds observed in the Trapezium Cluster in Orion. In this paper, we present a study based on low-resolution optical spectroscopic observations made with the Optical System for Imaging and low Resolution Integrated Spectroscopy, mounted on the 10.4 m Gran Telescopio CANARIAS, of two of these protostars. The spectrum of one of the objects shows evidence of accretion but not of outflows. In the latter object, the spectra show several emission lines indicating the presence of an actively accreting disk with outflow. We present estimates of the mass loss rate and the accretion rate from the disk, showing that the former exceeds the latter as observed in other known objects with evaporating disks. We also show evidence of a strong variability in the integrated flux observed in these objects as well as in the accretion and outflow diagnostics.

  12. The Cygnus loop - A detailed comparison of X-ray and optical emission

    NASA Technical Reports Server (NTRS)

    Cox, D. P.; Hester, J. J.

    1986-01-01

    A comparison at a resolution of 17 arcsec is presented between optical emission from forbidden O III and forbidden S II and the thermal X-ray emission for a field on the southeast edge of the Cygnus Loop SNR. The relationship between optical and X-ray emission in the field is described, generalizing to the Loop as a whole when possible. Several possible explanations for the presence of bright X-ray emission in the vicinity of optical emission are presented and evaluated based on the data. These mechanisms involve evaporation, gradual variations and gradients in the density of the preshock intercloud medium, and additional compression of material which has already been heated to X-ray temperatures by the adiabatic blast wave. The additional compression could result from rapid deceleration of the blast wave itself or from reshocking by reflected or bow shocks around dense clouds. Implications of the observations for models of SNR evolution and the interstellar medium are discussed.

  13. RAPID SPECTRAL CHANGES OF CYGNUS X-1 IN THE LOW/HARD STATE WITH SUZAKU

    SciTech Connect

    Yamada, S.; Makishima, K.; Negoro, H.; Torii, S.; Noda, H.; Mineshige, S.

    2013-04-20

    Rapid spectral changes in the hard X-ray on a timescale down to {approx}0.1 s are studied by applying a ''shot analysis'' technique to the Suzaku observations of the black hole binary Cygnus X-1, performed on 2008 April 18 during the low/hard state. We successfully obtained the shot profiles, covering 10-200 keV with the Suzaku HXD-PIN and HXD-GSO detector. It is notable that the 100-200 keV shot profile is acquired for the first time owing to the HXD-GSO detector. The intensity changes in a time-symmetric way, though the hardness changes in a time-asymmetric way. When the shot-phase-resolved spectra are quantified with the Compton model, the Compton y-parameter and the electron temperature are found to decrease gradually through the rising phase of the shot, while the optical depth appears to increase. All the parameters return to their time-averaged values immediately within 0.1 s past the shot peak. We have not only confirmed this feature previously found in energies below {approx}60 keV, but also found that the spectral change is more prominent in energies above {approx}100 keV, implying the existence of some instant mechanism for direct entropy production. We discuss possible interpretations of the rapid spectral changes in the hard X-ray band.

  14. Modelling Deep Water Habitats to Develop a Spatially Explicit, Fine Scale Understanding of the Distribution of the Western Rock Lobster, Panulirus cygnus

    PubMed Central

    Hovey, Renae K.; Van Niel, Kimberly P.; Bellchambers, Lynda M.; Pember, Matthew B.

    2012-01-01

    Background The western rock lobster, Panulirus cygnus, is endemic to Western Australia and supports substantial commercial and recreational fisheries. Due to and its wide distribution and the commercial and recreational importance of the species a key component of managing western rock lobster is understanding the ecological processes and interactions that may influence lobster abundance and distribution. Using terrain analyses and distribution models of substrate and benthic biota, we assess the physical drivers that influence the distribution of lobsters at a key fishery site. Methods and Findings Using data collected from hydroacoustic and towed video surveys, 20 variables (including geophysical, substrate and biota variables) were developed to predict the distributions of substrate type (three classes of reef, rhodoliths and sand) and dominant biota (kelp, sessile invertebrates and macroalgae) within a 40 km2 area about 30 km off the west Australian coast. Lobster presence/absence data were collected within this area using georeferenced pots. These datasets were used to develop a classification tree model for predicting the distribution of the western rock lobster. Interestingly, kelp and reef were not selected as predictors. Instead, the model selected geophysical and geomorphic scalar variables, which emphasise a mix of terrain within limited distances. The model of lobster presence had an adjusted D2 of 64 and an 80% correct classification. Conclusions Species distribution models indicate that juxtaposition in fine scale terrain is most important to the western rock lobster. While key features like kelp and reef may be important to lobster distribution at a broad scale, it is the fine scale features in terrain that are likely to define its ecological niche. Determining the most appropriate landscape configuration and scale will be essential to refining niche habitats and will aid in selecting appropriate sites for protecting critical lobster habitats. PMID

  15. The Soft State of Cygnus X-1 Observed with NuSTAR: A Variable Corona and a Stable Inner Disk

    NASA Astrophysics Data System (ADS)

    Walton, D. J.; Tomsick, J. A.; Madsen, K. K.; Grinberg, V.; Barret, D.; Boggs, S. E.; Christensen, F. E.; Clavel, M.; Craig, W. W.; Fabian, A. C.; Fuerst, F.; Hailey, C. J.; Harrison, F. A.; Miller, J. M.; Parker, M. L.; Rahoui, F.; Stern, D.; Tao, L.; Wilms, J.; Zhang, W.

    2016-07-01

    We present a multi-epoch hard X-ray analysis of Cygnus X-1 in its soft state based on four observations with the Nuclear Spectroscopic Telescope Array (NuSTAR). Despite the basic similarity of the observed spectra, there is clear spectral variability between epochs. To investigate this variability, we construct a model incorporating both the standard disk-corona continuum and relativistic reflection from the accretion disk, based on prior work on Cygnus X-1, and apply this model to each epoch independently. We find excellent consistency for the black hole spin and the iron abundance of the accretion disk, which are expected to remain constant on observational timescales. In particular, we confirm that Cygnus X-1 hosts a rapidly rotating black hole, 0.93≲ {a}* ≲ 0.96, in broad agreement with the majority of prior studies of the relativistic disk reflection and constraints on the spin obtained through studies of the thermal accretion disk continuum. Our work also confirms the apparent misalignment between the inner disk and the orbital plane of the binary system reported previously, finding the magnitude of this warp to be ˜10°-15°. This level of misalignment does not significantly change (and may even improve) the agreement between our reflection results and the thermal continuum results regarding the black hole spin. The spectral variability observed by NuSTAR is dominated by the primary continuum, implying variability in the temperature of the scattering electron plasma. Finally, we consistently observe absorption from ionized iron at ˜6.7 keV, which varies in strength as a function of orbital phase in a manner consistent with the absorbing material being an ionized phase of the focused stellar wind from the supergiant companion star.

  16. G141.2+5.0, A NEW PULSAR WIND NEBULA DISCOVERED IN THE CYGNUS ARM OF THE MILKY WAY

    SciTech Connect

    Kothes, R.; Foster, T. J.; Sun, X. H.; Reich, W.

    2014-04-01

    We report the discovery of the new pulsar wind nebula (PWN) G141.2+5.0 in data observed with the Dominion Radio Astrophysical Observatory's Synthesis Telescope at 1420 MHz. The new PWN has a diameter of about 3.'5, which translates to a spatial extent of about 4 pc at a distance of 4.0 kpc. It displays a radio spectral index of α ≈ –0.7, similar to the PWN G76.9+1.1. G141.2+5.0 is highly polarized up to 40% with an average of 15% in the 1420 MHz data. It is located in the center of a small spherical H I bubble, which is expanding at a velocity of 6 km s{sup –1} at a systemic velocity of v {sub LSR} = –53 km s{sup –1}. The bubble could be the result of the progenitor star's mass loss or the shell-type supernova remnant (SNR) created by the same supernova explosion in a highly advanced stage. The systemic LSR velocity of the bubble shares the velocity of H I associated with the Cygnus spiral arm, which is seen across the second and third quadrants and an active star-forming arm immediately beyond the Perseus arm. A kinematical distance of 4 ± 0.5 kpc is found for G141.2+5.0, similar to the optical distance of the Cygnus arm (3.8 ± 1.1 kpc). G141.2+5.0 represents the first radio PWN discovered in 17 years and the first SNR discovered in the Cygnus spiral arm, which is in stark contrast with the Perseus arm's overwhelming population of shell-type remnants.

  17. The Soft State of Cygnus X-1 Observed with NuSTAR: A Variable Corona and a Stable Inner Disk

    NASA Astrophysics Data System (ADS)

    Walton, D. J.; Tomsick, J. A.; Madsen, K. K.; Grinberg, V.; Barret, D.; Boggs, S. E.; Christensen, F. E.; Clavel, M.; Craig, W. W.; Fabian, A. C.; Fuerst, F.; Hailey, C. J.; Harrison, F. A.; Miller, J. M.; Parker, M. L.; Rahoui, F.; Stern, D.; Tao, L.; Wilms, J.; Zhang, W.

    2016-07-01

    We present a multi-epoch hard X-ray analysis of Cygnus X-1 in its soft state based on four observations with the Nuclear Spectroscopic Telescope Array (NuSTAR). Despite the basic similarity of the observed spectra, there is clear spectral variability between epochs. To investigate this variability, we construct a model incorporating both the standard disk-corona continuum and relativistic reflection from the accretion disk, based on prior work on Cygnus X-1, and apply this model to each epoch independently. We find excellent consistency for the black hole spin and the iron abundance of the accretion disk, which are expected to remain constant on observational timescales. In particular, we confirm that Cygnus X-1 hosts a rapidly rotating black hole, 0.93≲ {a}* ≲ 0.96, in broad agreement with the majority of prior studies of the relativistic disk reflection and constraints on the spin obtained through studies of the thermal accretion disk continuum. Our work also confirms the apparent misalignment between the inner disk and the orbital plane of the binary system reported previously, finding the magnitude of this warp to be ˜10°–15°. This level of misalignment does not significantly change (and may even improve) the agreement between our reflection results and the thermal continuum results regarding the black hole spin. The spectral variability observed by NuSTAR is dominated by the primary continuum, implying variability in the temperature of the scattering electron plasma. Finally, we consistently observe absorption from ionized iron at ˜6.7 keV, which varies in strength as a function of orbital phase in a manner consistent with the absorbing material being an ionized phase of the focused stellar wind from the supergiant companion star.

  18. First Dynamic Computations of Synchrotron Emission from the Cygnus A Radio Cavity: Evidence for Electron Pair Plasma in Cavity

    NASA Astrophysics Data System (ADS)

    Mathews, William G.

    2014-03-01

    Cosmic rays, thermal gas and magnetic fields in FRII radio cavities are assumed to come entirely from winds flowing from just behind the jet shocks. Combining analytic and computational methods, it is shown that the computed radio-electron energy distribution and synchrotron emissivity spectra everywhere in the Cygnus A radio cavity agree with radio observations of the Cygnus A lobes. The magnetic field energy density is small everywhere and evolves passively in the post-shock wind. Most synchrotron emission arises in recent post-shock material as it flows back along the radio cavity wall. Because it experienced less adiabatic expansion, the magnetic field in this young backflow is larger than elsewhere in the radio lobe, explaining the observed radio synchrotron limb-brightening. The boundary backflow decelerates due to small cavity pressure gradients, causing large-scale fields perpendicular to the backflow (and synchrotron emission) to grow exponentially unlike observations. However, if the field is random on subgrid (sub-kpc) scales, the computed field reproduces both the magnitude and slowly decreasing radio synchrotron emissivity observed along the backflow. The radio synchrotron spectrum and image computed with a small-scale random field agree with Very Large Array observations. The total relativistic energy density in the post-jet shock region required in computations to inflate the radio cavity matches the energy density of relativistic electrons observed in the post-shock region of Cygnus A. This indicates that the component in the jet and cavity that dominates the dynamical evolution is a relativistic pair plasma.

  19. First dynamic computations of synchrotron emission from the cygnus a radio cavity: Evidence for electron pair plasma in cavity

    SciTech Connect

    Mathews, William G.

    2014-03-01

    Cosmic rays, thermal gas and magnetic fields in FRII radio cavities are assumed to come entirely from winds flowing from just behind the jet shocks. Combining analytic and computational methods, it is shown that the computed radio-electron energy distribution and synchrotron emissivity spectra everywhere in the Cygnus A radio cavity agree with radio observations of the Cygnus A lobes. The magnetic field energy density is small everywhere and evolves passively in the post-shock wind. Most synchrotron emission arises in recent post-shock material as it flows back along the radio cavity wall. Because it experienced less adiabatic expansion, the magnetic field in this young backflow is larger than elsewhere in the radio lobe, explaining the observed radio synchrotron limb-brightening. The boundary backflow decelerates due to small cavity pressure gradients, causing large-scale fields perpendicular to the backflow (and synchrotron emission) to grow exponentially unlike observations. However, if the field is random on subgrid (sub-kpc) scales, the computed field reproduces both the magnitude and slowly decreasing radio synchrotron emissivity observed along the backflow. The radio synchrotron spectrum and image computed with a small-scale random field agree with Very Large Array observations. The total relativistic energy density in the post-jet shock region required in computations to inflate the radio cavity matches the energy density of relativistic electrons observed in the post-shock region of Cygnus A. This indicates that the component in the jet and cavity that dominates the dynamical evolution is a relativistic pair plasma.

  20. Hard X-ray Observation of Cygnus X-1 By the Marshall Imaging X-ray Experiment (MIXE2)

    NASA Technical Reports Server (NTRS)

    Minamitani, Takahisa; Apple, J. A.; Austin, R. A.; Dietz, K. L.; Koloziejczak, J. J.; Ramsey, B. D.; Weisskopf, M. C.

    1998-01-01

    The second generation of the Marshall Imaging X-ray Experiment (MIXE2) was flown from Fort Sumner, New Mexico on May 7-8, 1997. The experiment consists of coded-aperture telescope with a field of view of 1.8 degrees (FWHM) and an angular resolution of 6.9 arcminutes. The detector is a large (7.84x10(exp 4) sq cm) effective area microstrip proportional counter filled with 2.0x10(exp5) Pascals of xenon with 2% isobutylene. We present MIXE2 observation of the 20-80keV spectrum and timing variability of Cygnus X-1 made during balloon flight.

  1. CO outflows from high-mass Class 0 protostars in Cygnus-X

    NASA Astrophysics Data System (ADS)

    Duarte-Cabral, A.; Bontemps, S.; Motte, F.; Hennemann, M.; Schneider, N.; André, Ph.

    2013-10-01

    Context. The earliest phases of the formation of high-mass stars are not well known. It is unclear whether high-mass cores in monolithic collapse exist or not, and what the accretion process and origin of the material feeding the precursors of high-mass stars are. As outflows are natural consequences of the accretion process, they represent one of the few (indirect) tracers of accretion. Aims: We aim to search for individual outflows from high-mass cores in Cygnus X and to study the characteristics of the detected ejections. We compare these to what has been found for the low-mass protostars, to understand how ejection and accretion change and behave with final stellar mass. Methods: We used CO (2-1) PdBI observations towards six massive dense clumps, containing a total of 9 high-mass cores. We estimated the bolometric luminosities and masses of the 9 high-mass cores and measured the energetics of outflows. We compared our sample to low-mass objects studied in the literature and developed simple evolutionary models to reproduce the observables. Results: We find that 8 out of 9 high-mass cores are driving clear individual outflows. They are therefore true equivalents of Class 0 protostars in the high-mass regime. The remaining core, CygX-N53 MM2, has only a tentative outflow detection. It could be one of the first examples of a true individual high-mass prestellar core. We also find that the momentum flux of high-mass objects has a linear relation to the reservoir of mass in the envelope, as a scale up of the relations previously found for low-mass protostars. This suggests a fundamental proportionality between accretion rates and envelope masses. The linear dependency implies that the timescale for accretion is similar for high- and low-mass stars. Conclusions: The existence of strong outflows driven by high-mass cores in Cygnus X clearly indicates that high-mass Class 0 protostars exist. The collapsing envelopes of these Class 0 objects have similar sizes and a

  2. Spitzer IRS observations of the XA region in the cygnus loop supernova remnant

    SciTech Connect

    Sankrit, Ravi; Bautista, Manuel; Williams, Brian J.; Blair, William P.; Borkowski, Kazimierz J.; Long, Knox S.

    2014-05-20

    We report on spectra of two positions in the XA region of the Cygnus Loop supernova remnant obtained with the InfraRed Spectrograph on the Spitzer Space Telescope. The spectra span the 10-35 μm wavelength range, which contains a number of collisionally excited forbidden lines. These data are supplemented by optical spectra obtained at the Whipple Observatory and an archival UV spectrum from the International Ultraviolet Explorer. Coverage from the UV through the IR provides tests of shock wave models and tight constraints on model parameters. Only lines from high ionization species are detected in the spectrum of a filament on the edge of the remnant. The filament traces a 180 km s{sup –1} shock that has just begun to cool, and the oxygen to neon abundance ratio lies in the normal range found for Galactic H II regions. Lines from both high and low ionization species are detected in the spectrum of the cusp of a shock-cloud interaction, which lies within the remnant boundary. The spectrum of the cusp region is matched by a shock of about 150 km s{sup –1} that has cooled and begun to recombine. The post-shock region has a swept-up column density of about 1.3 × 10{sup 18} cm{sup –2}, and the gas has reached a temperature of 7000-8000 K. The spectrum of the Cusp indicates that roughly half of the refractory silicon and iron atoms have been liberated from the grains. Dust emission is not detected at either position.

  3. Near Infrared Diffuse Interstellar Bands Toward the Cygnus OB2 Association

    NASA Astrophysics Data System (ADS)

    Hamano, Satoshi; Kobayashi, Naoto; Kondo, Sohei; Sameshima, Hiroaki; Nakanishi, Kenshi; Ikeda, Yuji; Yasui, Chikako; Mizumoto, Misaki; Matsunaga, Noriyuki; Fukue, Kei; Yamamoto, Ryo; Izumi, Natsuko; Mito, Hiroyuki; Nakaoka, Tetsuya; Kawanishi, Takafumi; Kitano, Ayaka; Otsubo, Shogo; Kinoshita, Masaomi; Kawakita, Hideyo

    2016-04-01

    We obtained the near-infrared (NIR) high-resolution (R ≡ λ/Δλ ∼ 20,000) spectra of the seven brightest early-type stars in the Cygnus OB2 association for investigating the environmental dependence of diffuse interstellar bands (DIBs). The WINERED spectrograph mounted on the Araki 1.3 m telescope in Japan was used to collect data. All 20 of the known DIBs within the wavelength coverage of WINERED (0.91 < λ < 1.36 μm) were clearly detected along all lines of sight because of their high flux density in the NIR wavelength range and the large extinction. The equivalent widths (EWs) of DIBs were not correlated with the column densities of C2 molecules, which trace the patchy dense component, suggesting that the NIR DIB carriers are distributed mainly in the diffuse component. On the basis of the correlations among the NIR DIBs both for stars in Cyg OB2 and stars observed previously, λλ10780, 10792, 11797, 12623, and 13175 are found to constitute a “family,” in which the DIBs are correlated well over the wide EW range. In contrast, the EW of λ10504 is found to remain almost constant over the stars in Cyg OB2. The extinction estimated from the average EW of λ10504 (AV ∼ 3.6 mag) roughly corresponds to the lower limit of the extinction distribution of OB stars in Cyg OB2. This suggests that λ10504 is absorbed only by the foreground clouds, implying that the carrier of λ10504 is completely destroyed in Cyg OB2, probably by the strong UV radiation field. The different behaviors of the DIBs may be caused by different properties of the DIB carriers.

  4. Toxicity of Anacostia River, Washington, D.C., USA, sediment fed to mute swans (Cygnus olor)

    USGS Publications Warehouse

    Beyer, W.N.; Day, D.; Melancon, M.J.; Sileo, L.

    2000-01-01

    Sediment ingestion is sometimes the principal route by which waterfowl are exposed to environmental contaminants, and at severely contaminated sites waterfowl have been killed by ingesting sediment. Mute swans (Cygnus olor) were fed a diet for 6 weeks with a high but environmentally realistic concentration (24%) of sediment from the moderately polluted Anacostia River in the District of Columbia, USA, to estimate the sediment's toxicity. Control swans were fed the same diet without the sediment. Five organochlorine compounds were detected in the treated diets, but none of 22 organochlorine compounds included in the analyses was detected in livers of the treated swans. The concentrations of 24 polynuclear aromatic hydrocarbons measured in the treated diet were as high as 0.80 mg/kg, and they were thought to have been responsible for the observed induction of hepatic microsomal monooxygenase activity in livers. A concentration of 85 mg/kg of lead in the diet was enough to decrease red blood cell ALAD activity but was not high enough to cause more serious effects of lead poisoning. The dietary concentrations of Al, Fe, V, and Ba were high compared to the concentrations of these elements known to be toxic in laboratory feeding studies. However, the lack of accumulation in the livers of the treated swans suggested that these elements were not readily available from the ingested sediment. We did not study all potential toxic effects, but, on the basis of those that we did consider, we concluded that the treated swans were basically healthy after a chronic exposure to the sediment.

  5. Hadronic gamma-ray and neutrino emission from Cygnus X-3

    SciTech Connect

    Sahakyan, N.; Piano, G.; Tavani, M.

    2014-01-01

    Cygnus X-3 (Cyg X-3) is a remarkable Galactic microquasar (X-ray binary) emitting from radio to γ-ray energies. In this paper, we consider the hadronic model of emission of γ-rays above 100 MeV and their implications. We focus on the joint γ-ray and neutrino production resulting from proton-proton interactions within the binary system. We find that the required proton injection kinetic power, necessary to explain the γ-ray flux observed by AGILE and Fermi-LAT, is L{sub p} ∼ 10{sup 38} erg s{sup –1}, a value in agreement with the average bolometric luminosity of the hypersoft state (when Cyg X-3 was repeatedly observed to produce transient γ-ray activity). If we assume an increase of the wind density at the superior conjunction, the asymmetric production of γ-rays along the orbit can reproduce the observed modulation. According to observational constraints and our modeling, a maximal flux of high-energy neutrinos would be produced for an initial proton distribution with a power-law index α = 2.4. The predicted neutrino flux is almost two orders of magnitude less than the two-month IceCube sensitivity at ∼1 TeV. If the protons are accelerated up to PeV energies, the predicted neutrino flux for a prolonged 'soft X-ray state' would be a factor of about three lower than the one-year IceCube sensitivity at ∼10 TeV. This study shows that, for a prolonged soft state (as observed in 2006) possibly related to γ-ray activity and a hard distribution of injected protons, Cyg X-3 might be close to being detectable by cubic-kilometer neutrino telescopes such as IceCube.

  6. A Giant Radio Flare from Cygnus X-3 with Associated Gamma-Ray Emission

    NASA Technical Reports Server (NTRS)

    Corbel, S.; Dubus, G.; Tomsick, J. A.; Szostek, A.; Corbet, R. H. D.; Miller-Jones, J. C. A.; Richards, J. L.; Pooley, G.; Trushkin, S.; Dubois, R.; Hill, A. B.; Kerr, M.; Max-Moerbeck, W.; Readhead, A. C. S.; Bodaghee, A.; Tudose, V.; Parent, D.; Wilms, J.; Pottschmidt, K.

    2012-01-01

    With frequent flaring activity of its relativistic jets, Cygnus X-3 (Cyg X-3) is one of the most active microquasars and is the only Galactic black hole candidate with confirmed high energy gamma-ray emission, thanks to detections by Fermi/LAT and AGILE. In 2011, Cyg X-3 was observed to transit to a soft X-ray state, which is known to be associated with high-energy gamma-ray emission. We present the results of a multiwavelength campaign covering a quenched state, when radio emission from Cyg X-3 is at its weakest and the X-ray spectrum is very soft. A giant (approx 20 Jy) optically thin radio flare marks the end of the quenched state, accompanied by rising non-thermal hard X-rays. Fermi/LAT observations (E greater than or equal 100 MeV) reveal renewed gamma-ray activity associated with this giant radio flare, suggesting a common origin for all non-thermal components. In addition, current observations unambiguously show that the gamma-ray emission is not exclusively related to the rare giant radio flares. A 3-week period of gamma-ray emission is also detected when Cyg X-3 was weakly flaring in radio, right before transition to the radio quenched state. No gamma rays are observed during the one-month long quenched state, when the radio flux is weakest. Our results suggest transitions into and out of the ultrasoft X-ray (radio quenched) state trigger gamma-ray emission, implying a connection to the accretion process, and also that the gamma-ray activity is related to the level of radio flux (and possibly shock formation), strengthening the connection to the relativistic jets.

  7. INTERSTELLAR ENVIRONMENTS AND DUST PROPERTIES TOWARD CYGNUS OB2 NO. 12: A REASSESSMENT

    SciTech Connect

    Whittet, D. C. B.

    2015-10-01

    The B-type hypergiant Cygnus OB2 no. 12 is a popular target for studies of interstellar phenomena at visible-infrared wavelengths because of its exceptional brightness for a star dimmed by some 10 mag of visual extinction. A lack of detectable ice absorption has led investigators to regard the line of sight as a standard for studies of the “diffuse” interstellar medium (ISM), an assumption challenged both by observations of molecular gas toward the star and by uncertainties concerning the degree to which such a luminous object may affect its local environment. This paper presents a reassessment of the nature of the material responsible for extinction toward Cyg OB2 no. 12. The excess relative to other cluster members appears to occur in translucent clumps within an extensive network of clouds in the region. Attenuation of the ambient radiation field is sufficient in the cores of the clumps to support the presence of gas-phase molecules, but not to sustain detectable ice formation. In general, the optical properties of dust in the clumps are closely similar to those observed in typical diffuse interstellar material, with the notable exception of an unusually low value for the wavelength of maximum polarization. The implied enhancement of polarization by small grains is attributed to increased alignment efficiency in an enhanced magnetic field. This caveat apart, the results of the current paper provide reassurance that Cyg OB2 no. 12 is, indeed, an appropriate choice for studies that target diffuse and translucent phases of the ISM.

  8. Interstellar Environments and Dust Properties toward Cygnus OB2 No. 12: A Reassessment

    NASA Astrophysics Data System (ADS)

    Whittet, D. C. B.

    2015-10-01

    The B-type hypergiant Cygnus OB2 no. 12 is a popular target for studies of interstellar phenomena at visible-infrared wavelengths because of its exceptional brightness for a star dimmed by some 10 mag of visual extinction. A lack of detectable ice absorption has led investigators to regard the line of sight as a standard for studies of the “diffuse” interstellar medium (ISM), an assumption challenged both by observations of molecular gas toward the star and by uncertainties concerning the degree to which such a luminous object may affect its local environment. This paper presents a reassessment of the nature of the material responsible for extinction toward Cyg OB2 no. 12. The excess relative to other cluster members appears to occur in translucent clumps within an extensive network of clouds in the region. Attenuation of the ambient radiation field is sufficient in the cores of the clumps to support the presence of gas-phase molecules, but not to sustain detectable ice formation. In general, the optical properties of dust in the clumps are closely similar to those observed in typical diffuse interstellar material, with the notable exception of an unusually low value for the wavelength of maximum polarization. The implied enhancement of polarization by small grains is attributed to increased alignment efficiency in an enhanced magnetic field. This caveat apart, the results of the current paper provide reassurance that Cyg OB2 no. 12 is, indeed, an appropriate choice for studies that target diffuse and translucent phases of the ISM.

  9. Impacts of mute swans (Cygnus olor) on submerged aquatic vegetation in Illinois River Valley backwaters

    USGS Publications Warehouse

    Stafford, Joshua D.; Michael W. Eichholz,; Adam C. Phillips,

    2012-01-01

    Wetland loss in North America has been considerable and well documented, and the establishment of exotic species in remaining wetlands can further reduce their ability to support native flora and fauna. In the Chesapeake Bay and Great Lakes ecosystems, exotic mute swans (Cygnus olor) have been found to negatively impact wetlands through degradation of submerged aquatic vegetation (SAV) communities. Mute swan populations have expanded into many areas of mid-continental North America outside the Great Lakes ecosystem, but the environmental impact of these populations is not well known. Mid-continental wetlands in North America differ in physical characteristics (e.g., size, depth, and permanency) and aquatic vegetation species composition compared to wetlands in other areas where mute swans have been studied and, thus, may be more or less susceptible to degradation from swan herbivory. To investigate the impact of mute swan herbivory on SAV communities in mid-continent wetlands, we used exclosures to prevent swans from foraging in 2 wetland complexes in central Illinois. Above-ground biomass of vegetation did not differ between exclosures and controls; however, mean below-ground biomass was greater in exclosures (52.0 g/m2, SE = 6.0) than in controls (34.4 g/m2 SE = 4.0). Thus, although swan densities were lower in our study region compared to that of previous studies, we observed potentially detrimental impacts of swan herbivory on below-ground biomass of SAV. Our results indicate that both above-ground and below-ground impacts of herbivory should be monitored, and below-ground biomass may be most sensitive to swan foraging.

  10. A Chandra X-ray Study of Cygnus A. 2; The Nucleus

    NASA Technical Reports Server (NTRS)

    Young, Andrew J.; Wilson, Andrew; Terashima, Yuichi; Arnaud, Keith A.; Smith, David A.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    We report Chandra Advanced CCD Imaging Spectrometer and quasi-simultaneous Rossi X-Ray Timing Explorer (RXTE) observations of the nearby, powerful radio galaxy Cygnus A, with the present paper focusing on the properties of the active nucleus. In the Chandra observation, the hard (less than a few keV) X-ray emission is spatially unresolved with a size is approximately 1" (1.5 kpc, H(sub 0) = 50 km/s/Mpc) and coincides with the radio and near-infrared nuclei. In contrast, the soft (less than 2 keV) emission exhibits a bipolar nebulosity that aligns with the optical bipolar continuum and emission-line structures and approximately with the radio jet. In particular, the soft X-ray emission corresponds very well with the [O III] (lambda)5007 and H(alpha) + [N II] lambda(lambda)6548, 6583 nebulosity imaged with Hubble Space Telescope. At the location of the nucleus, there is only weak soft X-ray emission, an effect that may be intrinsic or result from a dust lane that crosses the nucleus perpendicular to the source axis. The spectra of the various X-ray components have been obtained by simultaneous fits to the six detectors. The compact nucleus is detected to 100 keV and is well described by a heavily absorbed power-law spectrum with Gamma(sub h) = 1.52(sup + 0.12, sub -0.12) (similar to other 0.12 narrow-line radio galaxies) and equivalent hydrogen column N(sub H)(nuc) = 2.0(sup +0.1, sub -0.1) x 10(exp 23)/sq cm. This 0.2 column is compatible with the dust obscuration to the near-infrared source for a normal gas-to-dust ratio. The soft (less than 2 keV) emission from the nucleus may be described by a power-law spectrum with the same index (i.e., Gamma(sub l) = Gamma(sub h), although direct fits suggest a slightly larger value for Gamma(sub l). Narrow emission lines from highly ionized neon and silicon, as well as a "neutral" Fe K(alpha) line, are detected in the nucleus and its vicinity (r approximately less than 2 kpc). The equivalent width (EW) of the Fe K(alpha) line

  11. OT1_sbontemp_1: Water emission from outflows and hot cores in the Cygnus X proto-stars

    NASA Astrophysics Data System (ADS)

    Bontemps, S.

    2010-07-01

    The impressive first results from the WISH GT key program by van Dishoeck et al. indicate that water emission is bright towards the embedded proto-stars of all masses. These emissions are tracing outflows and warm inner regions of the collapsing envelopes (radiatively heated hot cores) which are unique probes of the cooling of these regions and of the kinematics of the dense warm gas. But WISH is limited by the reduced number of targets, and by the unavoidable biases introduced by the stringent selection of sources. The intermediate to high mass range is critical to challenge protostellar evolution models, and we argue that water emission from a complete sample of proto-stars in this mass range will be an important piece of knowledge for outflows to trace indirectly accretion and for hot cores to follow their time of appearance. Only Cygnus X is nearby and rich enough to provide a large sample of such proto-stars. We propose here to dramatically change the level of significance of WISH results by observing as many as 92 proto-stars covering the (final stellar) mass range of 3 to 20 Msun in the single complex of Cygnus X.

  12. Confirmation via the continuum-fitting method that the spin of the black hole in Cygnus X-1 is extreme

    SciTech Connect

    Gou, Lijun; McClintock, Jeffrey E.; Steiner, James F.; Reid, Mark J.; Narayan, Ramesh; García, Javier; Remillard, Ronald A.; Orosz, Jerome A.; Hanke, Manfred

    2014-07-20

    In Gou et al., we reported that the black hole primary in the X-ray binary Cygnus X-1 is a near-extreme Kerr black hole with a spin parameter a{sub *} > 0.95 (3σ). We confirm this result while setting a new and more stringent limit: a{sub *} > 0.983 at the 3σ (99.7%) confidence level. The earlier work, which was based on an analysis of all three useful spectra that were then available, was possibly biased by the presence in these spectra of a relatively strong Compton power-law component: the fraction of the thermal seed photons scattered into the power law was f{sub s} = 23%-31%, while the upper limit for reliable application of the continuum-fitting method is f{sub s} ≲ 25%. We have subsequently obtained six additional spectra of Cygnus X-1 suitable for the measurement of spin. Five of these spectra are of high quality with f{sub s} in the range 10%-19%, a regime where the continuum-fitting method has been shown to deliver reliable results. Individually, the six spectra give lower limits on the spin parameter that range from a{sub *} > 0.95 to a{sub *} > 0.98, allowing us to conservatively conclude that the spin of the black hole is a{sub *} > 0.983 (3σ).

  13. The earliest phases of high-mass star formation: a 3 square degree millimeter continuum mapping of Cygnus X

    NASA Astrophysics Data System (ADS)

    Motte, F.; Bontemps, S.; Schilke, P.; Schneider, N.; Menten, K. M.; Broguière, D.

    2007-12-01

    Aims:Our current knowledge of high-mass star formation is mainly based on follow-up studies of bright sources found by IRAS, and is thus biased against its earliest phases, inconspicuous at infrared wavelengths. We therefore started searching, in an unbiased way and in the closest high-mass star-forming complexes, for the high-mass analogs of low-mass pre-stellar cores and class 0 protostars. Methods: We have made an extensive 1.2 mm continuum mosaicing study of the Cygnus X molecular cloud complex using the MAMBO cameras at the IRAM 30 m telescope. The ˜ 3°2 imaged areas cover all the high-column density (AV ≥ 15 mag) clouds of this nearby (~1.7 kpc) cloud complex actively forming OB stars. We then compared our millimeter maps with mid-infrared images, and have made SiO(2-1) follow-up observations of the best candidate progenitors of high-mass stars. Results: Our complete study of Cygnus X with ~0.09 pc resolution provides, for the first time, an unbiased census of massive young stellar objects. We discover 129 massive dense cores (FWHM size ~0.1 pc, M1.2~mm = 4-950 M_⊙, volume-averaged density ~105 cm-3), among which ~42 are probable precursors of high-mass stars. A large fraction of the Cygnus X dense cores (2/3 of the sample) remain undetected by the MSX satellite, regardless of the mass range considered. Among the most massive (≥40 M_⊙) cores, infrared-quiet objects are driving powerful outflows traced by SiO emission. Our study qualifies 17 cores as good candidates for hosting massive infrared-quiet protostars, while up to 25 cores potentially host high-luminosity infrared protostars. We fail to discover the high-mass analogs of pre-stellar dense cores (~0.1 pc, > 104 cm-3) in Cygnus X, but find several massive starless clumps (~ 0.8 pc, 7 × 103 cm-3) that might be gravitationally bound. Conclusions: Since our sample is derived from a single molecular complex and covers every embedded phase of high-mass star formation, it gives the first

  14. AN UPDATED LOOK AT BINARY CHARACTERISTICS OF MASSIVE STARS IN THE CYGNUS OB2 ASSOCIATION

    SciTech Connect

    Kiminki, Daniel C.; Kobulnicky, Henry A.

    2012-05-20

    This work provides a statistical analysis of the massive star binary characteristics in the Cygnus OB2 association using radial velocity information of 114 B3-O5 primary stars and orbital properties for the 24 known binaries. We compare these data to a series of Monte Carlo simulations to infer the intrinsic binary fraction and distributions of mass ratios, periods, and eccentricities. We model the distribution of mass ratio, log-period, and eccentricity as power laws and find best-fitting indices of {alpha} = 0.1 {+-} 0.5, {beta} = 0.2 {+-} 0.4, and {gamma} = -0.6 {+-} 0.3, respectively. These distributions indicate a preference for massive companions, short periods, and low eccentricities. Our analysis indicates that the binary fraction of the cluster is 44% {+-} 8% if all binary systems are (artificially) assumed to have P < 1000 days; if the power-law period distribution is extrapolated to 10{sup 4} years, then a plausible upper limit for bound systems, the binary fraction is {approx}90% {+-} 10%. Of these binary (or higher order) systems, {approx}45% will have companions close enough to interact during pre- or post-main-sequence evolution (semi-major axis {approx}<4.7 AU). The period distribution for P < 26 days is not well reproduced by any single power law owing to an excess of systems with periods around 3-5 days (0.08-0.31 AU) and a relative shortage of systems with periods around 7-14 days (0.14-0.62 AU). We explore the idea that these longer-period systems evolved to produce the observed excess of short-period systems. The best-fitting binary parameters imply that secondaries generate, on average, {approx}16% of the V-band light in young massive populations. This means that photometrically based distance measurements for young massive clusters and associations will be systematically low by {approx}8% (0.16 mag in the distance modulus) if the luminous contributions of unresolved secondaries are not taken into account.

  15. Understanding star formation in molecular clouds. III. Probability distribution functions of molecular lines in Cygnus X

    NASA Astrophysics Data System (ADS)

    Schneider, N.; Bontemps, S.; Motte, F.; Ossenkopf, V.; Klessen, R. S.; Simon, R.; Fechtenbaum, S.; Herpin, F.; Tremblin, P.; Csengeri, T.; Myers, P. C.; Hill, T.; Cunningham, M.; Federrath, C.

    2016-03-01

    The probability distribution function of column density (N-PDF) serves as a powerful tool to characterise the various physical processes that influence the structure of molecular clouds. Studies that use extinction maps or H2 column-density maps (N) that are derived from dust show that star-forming clouds can best be characterised by lognormal PDFs for the lower N range and a power-law tail for higher N, which is commonly attributed to turbulence and self-gravity and/or pressure, respectively. While PDFs from dust cover a large dynamic range (typically N ~ 1020-24 cm-2 or Av~ 0.1-1000), PDFs obtained from molecular lines - converted into H2 column density - potentially trace more selectively different regimes of (column) densities and temperatures. They also enable us to distinguish different clouds along the line of sight through using the velocity information. We report here on PDFs that were obtained from observations of 12CO, 13CO, C18O, CS, and N2H+ in the Cygnus X North region, and make a comparison to a PDF that was derived from dust observations with the Herschel satellite. The PDF of 12CO is lognormal for Av ~ 1-30, but is cut for higher Av because of optical depth effects. The PDFs of C18O and 13CO are mostly lognormal up to Av ~ 1-15, followed by excess up to Av ~ 40. Above that value, all CO PDFs drop, which is most likely due to depletion. The high density tracers CS and N2H+ exhibit only a power law distribution between Av ~ 15 and 400, respectively. The PDF from dust is lognormal for Av ~ 3-15 and has a power-law tail up to Av ~ 500. Absolute values for the molecular line column densities are, however, rather uncertain because of abundance and excitation temperature variations. If we take the dust PDF at face value, we "calibrate" the molecular line PDF of CS to that of the dust and determine an abundance [CS]/[H2] of 10-9. The slopes of the power-law tails of the CS, N2H+, and dust PDFs are -1.6, -1.4, and -2.3, respectively, and are thus consistent

  16. Long term variability of Cygnus X-1. IV. Spectral evolution 1999-2004

    NASA Astrophysics Data System (ADS)

    Wilms, J.; Nowak, M. A.; Pottschmidt, K.; Pooley, G. G.; Fritz, S.

    2006-02-01

    Continuing the observational campaign initiated by our group, we present the long term spectral evolution of the Galactic black hole candidate Cygnus X-1 in the X-rays and at 15 GHz. We present 200 pointed observations taken between early 1999 and late 2004 with the Rossi X-ray Timing Explorer and the Ryle radio telescope. The X-ray spectra are remarkably well described by a simple broken power law spectrum with an exponential cutoff. Physically motivated Comptonization models, e.g., by Titarchuk (1994, ApJ, 434, 570, compTT) and by Coppi (1999, in High Energy Processes in Accreting Black Holes, ed. J. Poutanen, & R. Svensson (San Francisco: ASP), ASP Conf. Ser., 161, 375, eqpair), can reproduce this simplicity; however, the success of the phenomenological broken power law models cautions against "overparameterizing" the more physical models. Broken power law models reveal a significant linear correlation between the photon index of the lower energy power law and the hardening of the power law at 10 keV. This phenomenological soft/hard power law correlation is partly attributable to correlations of broad band continuum components, rather than being dominated by the weak hardness/reflection fraction correlation present in the Comptonization model. Specifically, the Comptonization models show that the bolometric flux of a soft excess (e.g., disk component) is strongly correlated with the compactness ratio of the Comptonizing medium, with L_disk propto (ell_h/ell_s)-0.19. Over the course of our campaign, Cyg X-1 transited several times into the soft state, and exhibited a large number of "failed state transitions". The fraction of the time spent in such low radio emission/soft X-ray spectral states has increased from 10% in 1996-2000 to 34% since early 2000. We find that radio flares typically occur during state transitions and failed state transitions (at ell_h/ell_s˜ 3), and that there is a strong correlation between the 10-50 keV X-ray flux and the radio

  17. Delineation of Tundra Swan Cygnus c. columbianus populations in North America: geographic boundaries and interchange

    USGS Publications Warehouse

    Ely, Craig R.; Sladen, William J. L.; Wilson, Heather M.; Savage, Susan E.; Sowl, Kristine M.; Henry, Bill; Schwitters, Mike; Snowden, James

    2014-01-01

    North American Tundra Swans Cygnus c. columbianus are composed of two wellrecognised populations: an Eastern Population (EP) that breeds across northern Canada and north of the Brooks Range in Alaska, which migrates to the eastern seaboard of the United States, and a Western Population (WP) that breeds in coastal regions of Alaska south of the Brooks Range and migrates to western North America. We present results of a recent major ringing effort from across the breeding range in Alaska to provide a better definition of the geographic extent of the migratory divide in Alaska. We also reassess the staging and winter distributions of these populations based on locations of birds tracked using satellite transmitters, and recent recoveries and sightings of neck-collared birds. Summer sympatry of EP and WP Tundra Swans is very limited, and largely confined to a small area in northwest Alaska. Autumn migration pathways of EP and WP Tundra swans abut in southwest Saskatchewan, a region where migrating WP birds turn west, and EP birds deviate abruptly eastward. Overall, from 1989 to 2013 inclusive, 2.6% of recoveries or resightings reported to the USGS Bird Banding Laboratory were of birds that moved from the domain of the population in which they were initially captured to within the range of the other population; a proportion roughly comparable to the results of Limpert et al. (1991) for years before 1990. Of the 70 cross-boundary movements reported since 1989, 39% were of birds marked on breeding areas and 61% were of birds marked on wintering areas. Dispersing swans (i.e. those that made crossboundary movements) did not differ with respect to age or sex from those that did not move between populations. The Brooks Range in northern Alaska effectively separates the two populations within Alaska, but climate-induced changes in tundra breeding habitats and losses of wetlands on staging areas may alter the distribution for both of these populations.

  18. Understanding the Long-Term Spectral Variability of Cygnus X-1 from BATSE and ASM Observations

    NASA Technical Reports Server (NTRS)

    Zdziarski, Andrzej A.; Poutanen, Juri; Paciesas, William S.; Wen, Linqing; Six, N. Frank (Technical Monitor)

    2002-01-01

    We present a spectral analysis of observations of Cygnus X-1 by the RXTE/ASM (1.5-12 keV) and CGRO/BATSE (20-300 keV), including about 1200 days of simultaneous data. We find a number of correlations between intensities and hardnesses in different energy bands from 1.5 keV to 300 keV. In the hard (low) spectral state, there is a negative correlation between the ASM 1.5-12 keV flux and the hardness at any energy. In the soft (high) spectral state, the ASM flux is positively correlated with the ASM hardness (as previously reported) but uncorrelated with the BATSE hardness. In both spectral states, the BATSE hardness correlates with the flux above 100 keV, while it shows no correlation with the flux in the 20-100 keV range. At the same time, there is clear correlation between the BATSE fluxes below and above 100 keV. In the hard state, most of the variability can be explained by softening the overall spectrum with a pivot at approximately 50 keV. The observations show that there has to be another, independent variability pattern of lower amplitude where the spectral shape does not change when the luminosity changes. In the soft state, the variability is mostly caused by a variable hard (Comptonized) spectral component of a constant shape superimposed on a constant soft blackbody component. These variability patterns are in agreement with the dependence of the rms variability on the photon energy in the two states. We interpret the observed correlations in terms of theoretical Comptonization models. In the hard state, the variability appears to be driven mostly by changing flux in seed photons Comptonized in a hot thermal plasma cloud with an approximately constant power supply. In the soft state, the variability is consistent with flares of hybrid, thermal/nonthermal, plasma with variable power above a stable cold disk. Also, based on broadband pointed observations simultaneous with those of the ASM and BATSE, we find the intrinsic bolometric luminosity increases by a

  19. The Balmer-dominated northeast limb of the Cygnus loop supernova remnant

    NASA Astrophysics Data System (ADS)

    Hester, J. Jeff; Raymond, John C.; Blair, William P.

    1994-01-01

    We present a comprehensive investigation of the Balmar-dominated northeast limb of the Cygnus Loop supernova remnant. Data presented include H alpha (O III), and X-ray images, UV and visible spectrophotometry, and high-resolution spectroscopy. The two relatively bright Balmer-dominated filaments visible on the POSS prints are seen to be part of a very smooth and regular complex of filaments. These filaments mark the current location of the blast wave and are seen to bound the sharply limb-brightened X-ray emission, including the previously reported X-ray, 'halo.' The (O III)/h beta ratio throughout the region is approximately 0.1, except for regions in which the shock is undergoing a transition from nonradiative to incomplete radiative to incomplete radiative conditions. At these locations (O III) emission from the cooling region is quite strong, while collisionally excited Balmer-line emission can be weak because of photoionization of the preshock medium by UV from the nascent cooling region. As a result (O III)/H beta is greater than 100 in some locations. The nonradiative/radiative transition is best studied along the length of the northwestern of the two brightest filaments, where the shock velocity and swept-up column go from approximately 180 km/s and 1017/sq cm at one end to approximately 140 km/s and 8 x 1017/cm at the other. There are also a number of locations of such incomplete radiative emission where the shock has recently encountered denser regions with characteristic sizes of approximately 1018 cm. There is a considerable amount of evidence that the shock has decelerated from approximately 400 km/s to less than 200 km/s in the last 1000 yr. We interpret this as the result of the blast wave hitting the wall of a cavity which surround the supernova precursor and succeed in matching a wide range of data with a reflected shock model in which the density ofthe cavity wall is approximately 1.2/cu cm and the density in the interior of the cavity is about 0

  20. Observation of an excess of cosmic ray muons of energies 2 TeV from the direction of Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Battistoni, G.; Bellotti, E.; Bloise, C.; Bologna, G.; Campana, P.; Castagnoli, C.; Castellina, A.; Chiarella, V.; Ciocio, A.; Cundy, D.

    1985-01-01

    A high flux of muons from the Cygnus X-3 direction has been observed in NUSEX experiment at depths greater than 4600 hg/sq cm s.r. The excess muons show the 4.8 hour modulation in arrival time typical of this source. A study of this modulation was done in order to find the best value of the period and of the period derivative. The muon flux underground from NUSEX and SOUDAN (1800 hg/sq cm) experiments are used to determine the energy spectrum at sea level. The shape and the absolute intensities are found similar to those attributed to gamma rays responsible for production of air showers detected in direction of Cygnus X-3 in the energy range 10 to the 12th power to 10 to the 15th power eV.

  1. The Cosmic-Ray and Gas Content of the Cygnus Region as Measured in Gamma Rays by the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bottacini, E.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Harding, A. K.; Hays, E.; Thompson, D. J.; Troja, E.

    2011-01-01

    Context. The Cygnus region hosts a giant molecular-cloud complex which actively forms massive stars. Interactions of cosmic rays with interstellar gas and radiation fields make it shine at y-ray energies. Several gamma-ray pulsars and other energetic sources are seen in this direction. Aims. In this paper we analyse the gamma-ray emission measured by the Fermi Large Area Telescope in the energy range from 100 Me V to 100 Ge V in order to probe the gas and cosmic-ray content over the scale of the whole Cygnus complex. The gamma-ray emission on the scale of the central massive stellar clusters and from individual sources is addressed elsewhere. Methods. The signal from bright pulsars is largely reduced by selecting photons in their off-pulse phase intervals. We compare the diffuse gamma-ray emission with interstellar gas maps derived from radio/mm-wave lines and visual extinction data. and a global model of the region, including other pulsars and gamma-ray sources, is sought. Results. The integral H I emissivity above 100 MeV averaged over the whole Cygnus complex amounts to 12.06 +/- 0.11 (stat.) (+0.15 -0.84) (syst.J] x 10(exp -26) photons /s / sr / H-atom, where the systematic error is dominated by the uncertainty on the H I opacity to calculate its column densities. The integral emissivity and its spectral energy distribution are both consistent within the systematics with LAT measurements in the interstellar space near the solar system. The average X(sub co) N(H2)/W(sub co) ratio is found to be [1.68 +/- 0.05 (stat.) (H I opacity)] x 1020 molecules cm-2 (K km/s /r, consistent with other LAT measurements in the Local Arm. We detect significant gamma-ray emission from dark neutral gas for a mass corresponding to approx 40% of that traced by CO. The total interstellar mass in the Cygnus complex inferred from its gamma-ray emission amounts to 8(+5 -1) x 10(exp 6) Solar M at a distance of 1.4 kpc. Conclusions. Despite the conspicuous star formation activity and large

  2. Feedback at the Working Surface: A Joint X-ray and Low-Frequency Radio Spectral Study of the Cocoon Shock in Cygnus A

    NASA Astrophysics Data System (ADS)

    Wise, Michael W.; Rafferty, D. A.; McKean, J. P.

    2013-04-01

    We report on preliminary results from a joint spectral analysis of the cocoon shock region in Cygnus A using deep archival Chandra data and new low-frequency radio data from LOFAR. Being both bright in X-rays and the most powerful radio source in the local universe, the FRII radio galaxy Cygnus A represents an ideal opportunity to study the interaction between the jets produced by the central AGN and the surrounding intracluster medium (ICM) in which that AGN is embedded. Using the entire 235 ksec archival Chandra exposure, we have performed a spatially resolved, X-ray spectral analysis of the ICM in Cygnus A. By combining the resulting X-ray images and temperature maps with spectral index maps between 30-80 MHz and 120-180 MHz calculated from a recent, deep LOFAR observation, we can resolve the X-ray and radio emitting plasmas in any given region on spatial scales of 3-4 kpc over the central 100 kpc. We clearly resolve the cocoon shock surrounding Cygnus A and determine the Mach number of the shock as a function of position angle. Temperature jumps associated with this shock are detected over a large fraction of the total shock circumference. Significant non-thermal emission is also detected in the regions surrounding the SE and NW leading edges of the shock near the hotspots. In this talk, we will present a detailed analysis of the energetics of this interface region between the radio plasma inside the cocoon shock and the X-ray emitting gas outside the shock. Inside the shock, we will present constraints on the emission mechanisms in the jet, counter-jet, and hotspots based on the combined radio and X-ray spectra. Using maps of the spectral age derived from the LOFAR data and independent age estimates based on various cavity features seen in the X-ray image, we will present a picture of the evolution of the shock region in Cygnus A over the past 50 Myr. Finally, we will discuss the implications these observations have for AGN feedback models as well as the

  3. Image of the Black Hole, Cygnus X-1, Taken by the High Energy Astronomy Observatory (HEAO)-2

    NASA Technical Reports Server (NTRS)

    1980-01-01

    This image of the suspected Black Hole, Cygnus X-1, was the first object seen by the High Energy Astronomy Observatory (HEAO)-2/Einstein Observatory. According to the theories to date, one concept of a black hole is a star, perhaps 10 times more massive than the Sun, that has entered the last stages of stelar evolution. There is an explosion triggered by nuclear reactions after which the star's outer shell of lighter elements and gases is blown away into space and the heavier elements in the stellar core begin to collapse upon themselves. Once this collapse begins, the inexorable force of gravity continues to compact the material until it becomes so dense it is squeezed into a mere point and nothing can escape from its extreme gravitational field, not even light. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy.

  4. Chemical abundances of the secondary star in the neutron star X-ray binary Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Suárez-Andrés, L.; González Hernández, J. I.; Israelian, G.; Casares, J.; Rebolo, R.

    2015-03-01

    We present Utrecht Echelle Spectrograph@William Herschel Telescope high-resolution spectra of the low-mass X-ray binary (LMXB) Cygnus X-2. We have derived the stellar parameters of the secondary star using χ2 minimization procedure, and taking into account any possible veiling from the accretion disc. We determine a metallicity higher than solar ([Fe/H] = 0.27 ± 0.19), as seen also in the neutron star X-ray binary Centaurus X-4. The high quality of the secondary's spectrum allow us to determine the chemical abundances of O, Mg, Si, Ca, S, Ti, Fe, and Ni. We found that some α-elements (Mg, Si, S, Ti) are enhanced, consistent with a scenario of contamination of the secondary star during the supernova event. Surprisingly oxygen appears to be underabundant, whereas enhanced abundances of Fe and Ni are measured. Assuming that these abundances come from matter that has been processed in the SN and then captured by the secondary star, we explore different SN explosion scenarios with diverse geometries. A non-spherically symmetric SN explosion, with a low mass cut, seems to reproduce better the observed abundance pattern of the secondary star compared to the spherical case.

  5. THE 2010 MAY FLARING EPISODE OF CYGNUS X-3 IN RADIO, X-RAYS, AND {gamma}-RAYS

    SciTech Connect

    Williams, Peter K. G.; Bower, Geoffrey C.; Tomsick, John A.; Bodaghee, Arash; Pooley, Guy G.; Pottschmidt, Katja; Rodriguez, Jerome; Migliari, Simone; Trushkin, Sergei A.

    2011-06-01

    In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV {gamma}-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and {gamma}-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a {approx}3 day softening and recovery of the X-ray emission, followed almost immediately by a {approx}1 Jy radio flare at 15 GHz, followed by a 4.3{sigma} {gamma}-ray flare (E > 100 MeV) {approx}1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the {gamma}-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the {gamma}-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for {gamma}-ray emission from Cyg X-3.

  6. First 3 mm-VLBI imaging of the two-sided jet in Cygnus A. Zooming into the launching region

    NASA Astrophysics Data System (ADS)

    Boccardi, B.; Krichbaum, T. P.; Bach, U.; Bremer, M.; Zensus, J. A.

    2016-04-01

    Aims: We present for the first time Very Long Baseline Interferometry images of the radio galaxy Cygnus A at the frequency of 86 GHz. Thanks to the high spatial resolution of only ~200 Schwarzschild radii (RS), such observations provide an extremely detailed view of the nuclear regions in this archetypal object and allow us to derive important constraints for theoretical models describing the launching of relativistic jets. Methods: A pixel-based analysis of the jet outflow, which still appears two-sided on the scales probed, was performed. By fitting Gaussian functions to the transverse intensity profiles, we could determine the jet width in the nuclear region. Results: The base of the jets appears wide. The minimum measured transverse width of ~(227 ± 98) RS is significantly larger than the radius of the innermost stable circular orbit, suggesting that the outer accretion disk is contributing to the jet launching. The existence of a faster and Doppler de-boosted inner section, powered either from the rotation of the inner regions of the accretion disk or by the spinning black hole, is suggested by the kinematic properties and by the observed limb brightening of the flow.

  7. Behaviour of wintering Tundra Swans Cygnus columbianus columbianus at the Eel River delta and Humboldt Bay, California, USA

    USGS Publications Warehouse

    Black, Jeffrey M.; Gress, Carol; Byers, Jacob W.; Jennings, Emily; Ely, Craig

    2010-01-01

    Tundra Swan Cygnus columbianus columbinanus phenology and behaviour at the Eel River delta and southern Humboldt Bay in northern California, USA, is described. Counts made each January from 1963 onwards peaked at 1,502 swans in 1988. Monthly counts recorded during the 2006/07 and 2008/09 winters peaked in February, at 1,033 and 772 swans respectively. Swans roosted on ephemeral ponds at the Humboldt Bay National Wildlife Refuge, on ephemeral ponds within grassland pastures in the vicinity of the Refuge, and perhaps also used the Eel River as a roost. Flights between Refuge roosts and the pastures and ponds occurred in the two hours after sunrise and before dark. In winters 2008/09 and 2009/10, the percentage of cygnets in the flocks was 10.6% and 21.4% respectively, and increased to =31% cygnets each year after most swans had departed from the area in March. Average brood size in 2009/10 was 2.1 cygnets. Daily activities consisted of foraging (44.9% of activities recorded), comfort behaviour (22.1%), locomotion (16.2%) and vigilance (15.5%). Eight neck-collared swans identified in the wintering flock were marked at four locations in different parts of Alaska, up to 1,300 km apart.

  8. Detection of a novel circovirus in mute swans (Cygnus olor) by using nested broad-spectrum PCR.

    PubMed

    Halami, M Y; Nieper, H; Müller, H; Johne, R

    2008-03-01

    Circoviruses are the causative agents of acute and chronic diseases in several animal species. Clinical symptoms of circovirus infections range from depression and diarrhoea to immunosuppression and feather disorders in birds. Eleven different members of the genus Circovirus are known so far, which infect pigs and birds in a species-specific manner. Here, a nested PCR was developed for the detection of a broad range of different circoviruses in clinical samples. Using this assay, a novel circovirus was detected in mute swans (Cygnus olor) found dead in Germany in 2006. Sequence analysis of the swan circovirus (SwCV) genome, amplified by multiply primed rolling-circle amplification and PCR, indicates that SwCV is a distinct virus most closely related to the goose circovirus (73.2% genome sequence similarity). Sequence variations between SwCV genomes derived from two different individuals were high (15.5% divergence) and mainly confined to the capsid protein-encoding region. By PCR testing of 32 samples derived from swans found dead in two different regions of Germany, detection rates of 20.0 and 77.3% were determined, thus indicating a high incidence of SwCV infection. The clinical significance of SwCV infection, however, needs to be investigated further. PMID:18082907

  9. The complete mitochondrial genomes of the whistling duck (Dendrocygna javanica) and black swan (Cygnus atratus): dating evolutionary divergence in Galloanserae.

    PubMed

    Jiang, Feng; Miao, Yongwang; Liang, Wei; Ye, Haiyan; Liu, Hailin; Liu, Bin

    2010-07-01

    Galloanserae is an ancient and diverse avian group, for which comprehensive molecular evidence relevant to phylogenetic analysis in the context of molecular chronology is lacking. In this study, we present two additional mitochondrial genome sequences of Galloanserae (the whistling duck, Dendrocygna javanica, and the black swan, Cygnus atratus) to broaden the scope of molecular phylogenetic reconstruction. The lengths of the whistling duck's and black swan's mitochondrial genomes are 16,753 and 16,748 bases, respectively. Phylogenetic analyses suggest that Dendrocygna is more likely to be in a basal position of the branch consisting of Anatinae and Anserinae, an affiliation that does not conform to its traditional classification. Bayesian approaches were employed to provide a rough timescale for Galloanserae evolution. In general, a narrow range of 95% confidence intervals gave younger estimates than those based on limited genes and estimated that at least two lineages originated before the Coniacian epoch around 90 MYA, well before the Cretaceous-Tertiary boundary. In addition, these results, which were compatible with estimates from fossil evidence, also imply that the origin of numerous genera in Anseriformes took place in the late Oligocene to early Miocene. Taken together, the results presented here provide a working framework for future research on Galloanserae evolution, and they underline the utility of whole mitochondrial genome sequences for the resolution of deep divergence. PMID:19823953

  10. The velocity dependence of X-ray emission due to Charge Exchange: Applications in the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    Cumbee, Renata; Lyons, David; Mullen, Patrick; Shelton, Robin L.; Stancil, Phillip C.; Schultz, David R.

    2016-04-01

    The fundamental collisional process of charge exchange (CX) has been been established as a primary source of X-ray emission from the heliosphere [1], planetary exospheres [2], and supernova remnants [3,4]. In this process, X-ray emission results from the capture of an electron by a highly charged ion from a neutral atom or molecule, to form a highly-excited, high charge state ion. As the captured electron cascades down to the lowest energy level, photons are emitted, including X-rays.To provide reliable CX-induced X-ray spectral models to realistically simulate high-energy astrophysical environments, line ratios and spectra are computed using theoretical CX cross-sections obtained with the multi-channel Landau-Zener, atomic-orbital close-coupling, and classical-trajectory Monte Carlo methods for various collisional velocities. Collisions of bare and H-like C to Al ions with H, He, and H2 are considered. Using these line ratios, XSPEC models of CX emission in the northeast rim of the Cygnus Loop supernova remnant will be shown as an example with ion velocity dependence.[1] Henley, D. B. & Shelton, R. L. 2010, ApJSS, 187, 388[2] Dennerl, K. et al. 2002, A&A 386, 319[3] Katsuda, S. et al. 2011, ApJ 730 24[4] Cumbee, R. S. et al. 2014, ApJ 787 L31

  11. The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-Rays, and gamma-Rays

    NASA Technical Reports Server (NTRS)

    Williams, Peter K. G.; Tomsick, John A.; Bodaghee, Arash; Bower, Geoffrey C.; Pooley, Guy G.; Pottschmidt, Katja; Rodriguez, Jerome; Wilms, Joern; Migliari, Simone; Trushkin, Sergei A.

    2011-01-01

    In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV gamma-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich dataset of radio, hard and soft X-ray, and gamma-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a approx.3-d softening and recovery of the X-ray emission, followed almost immediately by a approx.1-Jy radio flare at 15 GHz, followed by a 4.3sigma gamma-ray flare (E > 100 MeV) approx.1.5 d later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the gamma-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the gamma-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for gamma-ray emission from Cyg X-3.

  12. The reflection component from Cygnus X-1 in the soft state measured by NuSTAR and Suzaku

    SciTech Connect

    Tomsick, John A.; Boggs, Steven E.; Craig, William W.; Nowak, Michael A.; Parker, Michael; Fabian, Andy C.; Miller, Jon M.; King, Ashley L.; Harrison, Fiona A.; Forster, Karl; Fürst, Felix; Grefenstette, Brian W.; Madsen, Kristin K.; Bachetti, Matteo; Barret, Didier; Christensen, Finn E.; Hailey, Charles J.; Natalucci, Lorenzo; Pottschmidt, Katja; Ross, Randy R.; and others

    2014-01-01

    The black hole binary Cygnus X-1 was observed in late 2012 with the Nuclear Spectroscopic Telescope Array (NuSTAR) and Suzaku, providing spectral coverage over the ∼1-300 keV range. The source was in the soft state with a multi-temperature blackbody, power law, and reflection components along with absorption from highly ionized material in the system. The high throughput of NuSTAR allows for a very high quality measurement of the complex iron line region as well as the rest of the reflection component. The iron line is clearly broadened and is well described by a relativistic blurring model, providing an opportunity to constrain the black hole spin. Although the spin constraint depends somewhat on which continuum model is used, we obtain a {sub *} > 0.83 for all models that provide a good description of the spectrum. However, none of our spectral fits give a disk inclination that is consistent with the most recently reported binary values for Cyg X-1. This may indicate that there is a >13° misalignment between the orbital plane and the inner accretion disk (i.e., a warped accretion disk) or that there is missing physics in the spectral models.

  13. OBSERVATION OF TeV GAMMA RAYS FROM THE CYGNUS REGION WITH THE ARGO-YBJ EXPERIMENT

    SciTech Connect

    Bartoli, B.; Catalanotti, S.; Bernardini, P.; Bleve, C.; Bi, X. J.; Cao, Z.; Chen, S. Z.; Chen, Y.; Bolognino, I.; Branchini, P.; Budano, A.; Calabrese Melcarne, A. K.; Cardarelli, R.; Cattaneo, C.; Chen, T. L.; Creti, P.; Cui, S. W.; Dai, B. Z.; D'Ali Staiti, G.; Collaboration: ARGO-YBJ Collaboration; and others

    2012-02-15

    We report the observation of TeV {gamma}-rays from the Cygnus region using the ARGO-YBJ data collected from 2007 November to 2011 August. Several TeV sources are located in this region including the two bright extended MGRO J2019+37 and MGRO J2031+41. According to the Milagro data set, at 20 TeV MGRO J2019+37 is the most significant source apart from the Crab Nebula. No signal from MGRO J2019+37 is detected by the ARGO-YBJ experiment, and the derived flux upper limits at the 90% confidence level for all the events above 600 GeV with medium energy of 3 TeV are lower than the Milagro flux, implying that the source might be variable and hard to be identified as a pulsar wind nebula. The only statistically significant (6.4 standard deviations) {gamma}-ray signal is found from MGRO J2031+41, with a flux consistent with the measurement by Milagro.

  14. VERY LARGE ARRAY H I ZEEMAN OBSERVATIONS OF THE CYGNUS X REGION: DR 22 AND ON 2

    SciTech Connect

    Mayo, E. A.; Troland, T. H. E-mail: troland@pa.uky.edu

    2012-02-15

    We have used the Very Large Array to study the Zeeman effect in 21 cm H I absorption lines from two star-forming regions in the Cygnus X complex, DR 22 and ON 2. We measure the line-of-sight magnetic field toward these regions, finding B{sub los} = -84 {+-} 11 {mu}G toward the DR 22 H II region and B{sub los} < 50 {mu}G toward each of the two H II regions in ON 2. We interpret these results in terms of two different models. In one model, we assume that the H I Zeeman effect is a measure of magnetic fields in the associated molecular clouds. If so, then the DR 22 molecular cloud is magnetically subcritical, that is, magnetically dominated. The ON 2 molecular clouds are magnetically supercritical. In a second model, we assume that the H I Zeeman effect is a measure of magnetic fields in photon-dominated regions where the gas has been compressed (and the field amplified) by absorption of stellar radiation. We find that this second model, where the measured field strength has been affected by star formation, accounts well for the DR 22 H I Zeeman effect. This same model, however, overpredicts the magnetic field in ON 2. ON 2 may be a region where the magnetic field is energetically insignificant or where the field happens to lie nearly in the plane of the sky.

  15. Theoretical interpretation of the HEAO-3 observations of Cygnus X-3 under the HEAO-3 Guest Investigator Program

    NASA Technical Reports Server (NTRS)

    Marscher, Alan P.

    1987-01-01

    A model of the galactic X-ray source Cygnus X-3 (Cyg X-3) is presented which deviates from previous models by positing that the X-rays originate in a jet rather than a binary system consiting of an ordinary star and a collapsed object. In the new model, the 4.8 hour period of Cyg X-3 is caused by variable absorption which occurs as the jet precesses. The primary role of the accretion disk corona (ADC) in modulating Cyg X-3 radiation is to make the observed intensity of a blob of material in a jet appear dimmer by absorption. The needed derivation of the positional dependence of the density of the ADC is freed of some complications by assuming that only the inner regions of the disk are precessing, with a period shorter than 4.8 hours. This model permits the secondary star to be a supergiant, as indicated by the luminosity of the system. The model is especially helpful in interpreting production of radio outbursts and very high energy gamma rays.

  16. HIGHLY IONIZED Fe-K ABSORPTION LINE FROM CYGNUS X-1 IN THE HIGH/SOFT STATE OBSERVED WITH SUZAKU

    SciTech Connect

    Yamada, S.; Yoshikawa, A.; Makishima, K.; Torii, S.; Noda, H.; Mineshige, S.; Ueda, Y.; Kubota, A.; Gandhi, P.; Done, C.

    2013-04-20

    We present observations of a transient He-like Fe K{alpha} absorption line in Suzaku observations of the black hole binary Cygnus X-1 on 2011 October 5 near superior conjunction during the high/soft state, which enable us to map the full evolution from the start to the end of the episodic accretion phenomena or dips for the first time. We model the X-ray spectra during the event and trace their evolution. The absorption line is rather weak in the first half of the observation, but instantly deepens for {approx}10 ks, and weakens thereafter. The overall change in equivalent width is a factor of {approx}3, peaking at an orbital phase of {approx}0.08. This is evidence that the companion stellar wind feeding the black hole is clumpy. By analyzing the line with a Voigt profile, it is found to be consistent with a slightly redshifted Fe XXV transition, or possibly a mixture of several species less ionized than Fe XXV. The data may be explained by a clump located at a distance of {approx}10{sup 10-12} cm with a density of {approx}10{sup (-13)-(-11)} g cm{sup -3}, which accretes onto and/or transits the line of sight to the black hole, causing an instant decrease in the observed degree of ionization and/or an increase in density of the accreting matter. Continued monitoring for individual events with future X-ray calorimeter missions such as ASTRO-H and AXSIO will allow us to map out the accretion environment in detail and how it changes between the various accretion states.

  17. Migration of Tundra Swans (Cygnus columbianus) Wintering in Japan Using Satellite Tracking: Identification of the Eastern Palearctic Flyway.

    PubMed

    Chen, Wenbo; Doko, Tomoko; Fujita, Go; Hijikata, Naoya; Tokita, Ken-Ichi; Uchida, Kiyoshi; Konishi, Kan; Hiraoka, Emiko; Higuchi, Hiroyoshi

    2016-02-01

    Migration through the Eastern Palearctic (EP) flyway by tundra swans (Cygnus columbianus) has not been thoroughly documented. We satellite-tracked the migration of 16 tundra swans that winter in Japan. The objectives of this study were 1) to show the migration pattern of the EP flyway of tundra swans; 2) to compare this pattern with the migration pattern of whooper swans; and 3) to identify stopover sites that are important for these swans' conservation. Tundra swans were captured at Kutcharo Lake, Hokkaido, in 2009-2012 and satellite-tracked. A new method called the "MATCHED (Migratory Analytical Time Change Easy Detection) method" was developed. Based on median, the spring migration began on 18 April and ended on 27 May. Autumn migration began on 9 September and ended on 2 November. The median duration of the spring and autumn migrations were 48 and 50 days, respectively. The mean duration at one stopover site was 5.5 days and 6.8 days for the spring and autumn migrations, respectively. The number of stopover sites was 3.0 and 2.5 for the spring and autumn migrations, respectively. The mean travel distances for the spring and autumn migrations were 6471 and 6331 km, respectively. Seven migration routes passing Sakhalin, the Amur River, and/or Kamchatka were identified. There were 15, 32, and eight wintering, stopover, and breeding sites, respectively. The migration routes and staging areas of tundra swans partially overlap with those of whooper swans, whose migration patterns have been previously documented. The migration patterns of these two swan species that winter in Japan confirm the importance of the Amur River, Udyl' Lake, Shchastya Bay, Aniva Bay, zaliv Chayvo Lake, zal Piltun Lake, zaliv Baykal Lake, Kolyma River, Buyunda River, Sen-kyuyel' Lake, and northern coastal areas of the Sea of Okhotsk.

  18. Migration of Tundra Swans (Cygnus columbianus) Wintering in Japan Using Satellite Tracking: Identification of the Eastern Palearctic Flyway.

    PubMed

    Chen, Wenbo; Doko, Tomoko; Fujita, Go; Hijikata, Naoya; Tokita, Ken-Ichi; Uchida, Kiyoshi; Konishi, Kan; Hiraoka, Emiko; Higuchi, Hiroyoshi

    2016-02-01

    Migration through the Eastern Palearctic (EP) flyway by tundra swans (Cygnus columbianus) has not been thoroughly documented. We satellite-tracked the migration of 16 tundra swans that winter in Japan. The objectives of this study were 1) to show the migration pattern of the EP flyway of tundra swans; 2) to compare this pattern with the migration pattern of whooper swans; and 3) to identify stopover sites that are important for these swans' conservation. Tundra swans were captured at Kutcharo Lake, Hokkaido, in 2009-2012 and satellite-tracked. A new method called the "MATCHED (Migratory Analytical Time Change Easy Detection) method" was developed. Based on median, the spring migration began on 18 April and ended on 27 May. Autumn migration began on 9 September and ended on 2 November. The median duration of the spring and autumn migrations were 48 and 50 days, respectively. The mean duration at one stopover site was 5.5 days and 6.8 days for the spring and autumn migrations, respectively. The number of stopover sites was 3.0 and 2.5 for the spring and autumn migrations, respectively. The mean travel distances for the spring and autumn migrations were 6471 and 6331 km, respectively. Seven migration routes passing Sakhalin, the Amur River, and/or Kamchatka were identified. There were 15, 32, and eight wintering, stopover, and breeding sites, respectively. The migration routes and staging areas of tundra swans partially overlap with those of whooper swans, whose migration patterns have been previously documented. The migration patterns of these two swan species that winter in Japan confirm the importance of the Amur River, Udyl' Lake, Shchastya Bay, Aniva Bay, zaliv Chayvo Lake, zal Piltun Lake, zaliv Baykal Lake, Kolyma River, Buyunda River, Sen-kyuyel' Lake, and northern coastal areas of the Sea of Okhotsk. PMID:26853870

  19. Self-Consistent Thermal Accretion Disk Corona Models for Compact Objects. II; Application to Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Dove, James B.; Wilms, Joern; Maisack, Michael; Begelman, Mitchell C.

    1997-01-01

    We apply our self-consistent accretion disk corona (ADC) model, with two different geometries, to the broadband X-ray spectrum of the black hole candidate Cygnus X-1. As shown in a companion paper, models in which the Comptonizing medium is a slab surrounding the cold accretion disk cannot have a temperature higher than about 140 keV for optical depths greater than 0.2, resulting in spectra that are much softer than the observed 10-30 keV spectrum of Cyg X-1. In addition, the slab-geometry models predict a substantial "soft excess" at low energies, a feature not observed for Cyg X-1, and Fe K-alpha fluorescence lines that are stronger than observed. Previous Comptonization models in the literature have invoked a slab geometry with optical depth tau(sub T) approx. greater than 0.3 and coronal temperature T(sub c) approx. 150 keV, but they are not self-consistent. Therefore, ADC models with a slab geometry are not appropriate for explaining the X-ray spectrum of Cyg X-1. Models with a spherical corona and an exterior disk, however, predict much higher self-consistent coronal temperatures than the slab-geometry models. The higher coronal temperatures are due to the lower amount of reprocessing of coronal radiation in the accretion disk, giving rise to a lower Compton cooling rate. Therefore, for the sphere-plus-disk geometry, the predicted spectrum can be hard enough to describe the observed X-ray continuum of Cyg X-1 while predicting Fe fluorescence lines having an equivalent width of approx. 40 eV. Our best-fit parameter values for the sphere-plus-disk geometry are tau(sub T) approx. equal to 1.5 and T(sub c) approx. equal to 90 keV.

  20. Avian paramyxovirus serotype 1 (Newcastle disease virus), avian influenza virus and salmonella spp. in mute swans (Cygnus olor) in the great lakes region and atlantic coast of the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since their introduction to the United States in the late 19th century, mute swans (Cygnus olor) have become a nuisance species by causing damage to aquatic habitats, acting aggressive towards humans, competing with native waterfowl, and by potentially serving as a reservoir of infectious diseases t...

  1. ASGARD: A LARGE SURVEY FOR SLOW GALACTIC RADIO TRANSIENTS. I. OVERVIEW AND FIRST RESULTS

    SciTech Connect

    Williams, Peter K. G.; Bower, Geoffrey C.; Croft, Steve; Keating, Garrett K.; Law, Casey J.; Wright, Melvyn C. H.

    2013-01-10

    Searches for slow radio transients and variables have generally focused on extragalactic populations, and the basic parameters of Galactic populations remain poorly characterized. We present a large 3 GHz survey performed with the Allen Telescope Array (ATA) that aims to improve this situation: ASGARD, the ATA Survey of Galactic Radio Dynamism. ASGARD observations spanned two years with weekly visits to 23 deg{sup 2} in two fields in the Galactic plane, totaling 900 hr of integration time on science fields and making it significantly larger than previous efforts. The typical blind unresolved source detection limit was 10 mJy. We describe the observations and data analysis techniques in detail, demonstrating our ability to create accurate wide-field images while effectively modeling and subtracting large-scale radio emission, allowing standard transient-and-variability analysis techniques to be used. We present early results from the analysis of two pointings: one centered on the microquasar Cygnus X-3 and one overlapping the Kepler field of view (l = 76 Degree-Sign , b = +13. Degree-Sign 5). Our results include images, catalog statistics, completeness functions, variability measurements, and a transient search. Out of 134 sources detected in these pointings, the only compellingly variable one is Cygnus X-3, and no transients are detected. We estimate number counts for potential Galactic radio transients and compare our current limits to previous work and our projection for the fully analyzed ASGARD data set.

  2. A survey of surveys

    SciTech Connect

    Kent, S.M.

    1994-11-01

    A new era for the field of Galactic structure is about to be opened with the advent of wide-area digital sky surveys. In this article, the author reviews the status and prospects for research for 3 new ground-based surveys: the Sloan Digital Sky Survey (SDSS), the Deep Near-Infrared Survey of the Southern Sky (DENIS) and the Two Micron AU Sky Survey (2MASS). These surveys will permit detailed studies of Galactic structure and stellar populations in the Galaxy with unprecedented detail. Extracting the information, however, will be challenging.

  3. A holistic view of a black hole binary: bringing together spectral, timing, and polarization analysis of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Grinberg, Victoria

    2014-01-01

    The microquasar Cygnus X-1 is a persistent high mass X-ray binary, consisting of an O-type supergiant and a stellar mass black hole, and therefore one of those systems which are often considered downscaled versions of AGN, an analogy supported in Cyg X-1 by observations of radio jets. The size and proximity of such systems allow us to observe phenomena on time-scales which are not accessible in their supermassive siblings. Cyg X-1 shows distinct X-ray states, characterized by X-ray spectral and timing properties. Radio behavior is strongly correlated with the X-ray states and a jet-break exists in the mid-IR range in the hard state. The source state is therefore essential for the interpretation of data at all wavelengths. For most observations lacking broadband X-ray coverage, however, the exact state determination proves challenging. In this work, I will present a recently developed novel approach that uses data from all sky monitors such as RXTE-ASM, MAXI, Swift-BAT, and Fermi-GBM to define states and state transitions on a timescales of a few hours over a period of more than 17 years. This approach can be used to investigate the context of high resolution observations of Cyg X-1 with Chandra and XMM, and to conduct state-resolved polarization analysis with INTEGRAL. I then combine spectral and model-independent X-ray timing analysis of over 1900 RXTE orbits over 14 years and investigate the evolution of Fourier-dependent timing parameters such as power spectra, coherence, and time lag at different photon energies over all spectral states. Results include a correlation between the shape of the power and time lag spectra in all hard and intermediate states, a photon-energy dependent increase of the fractional rms in the soft state, and a strong energy-dependency of the power spectra shapes during state transitions. The findings are crucial for constraining physical models for accretion and ejection in compact objects and for comparisons with other accreting

  4. Copper storage in the liver of the wild mute swan (Cygnus olor). Its possible relation to pollution of harbor waters by antifouling paints

    SciTech Connect

    Molnar, J.J.

    1983-12-01

    Postmortem examination of three wild mute swans (Cygnus olor) from a harbor area disclosed an unusual black discoloration of the liver. Chemical, histochemical, and microscopic studies, along with electron-probe microanalysis, showed that cytoplasmic pigment granules in the liver cells contained a copper-protein complex. Similar findings have been reported in Danish and English studies on large numbers of wild mute swans. Two control mute swans from The Bronx Zoo had negligible amounts of hepatic copper. The striking difference between the wild and the captive swans in hepatic copper content suggests that the copper in the wild swans was of environmental origin, most likely from copper-rich antifouling paint used extensively in the marine industry. Flakes of this paint may be ingested by swans searching for food in the sediment of harbor waters.

  5. Isophotes of a field in the Cygnus loop photographed in the (O III) and (N II)+H. cap alpha. lines

    SciTech Connect

    Sitnik, T.G.; Toropova, M.S.

    1982-11-01

    From interference-filter image-tube photographs of a 9' field in the western part of the Cygnus Loop supernova remnant, taken in the lambda5007 (O III) and lambdalambda 6584, 6563 (N II) + H..cap alpha.. lines, sets of isophotes are derived by an equidensitometry technique based on the Sabattier effect. The emission regions in these lines exhibit a relative displacement, interpreted as evidence for radiative cooling of the gas behind the shock generated in the supernova outburst. An explanation is offered for the differing morphology of the nebular filaments in the (O III) and (N II) + H..cap alpha.. lines. The anomalously high I/sub Otsi/II/I/sub H/..beta.. intensity ratio may reflect a spatial separation of the corresponding emission zones.

  6. Study of eclipsing binary and multiple systems in ob associations. II. The cygnus ob region: V443 Cyg, V456 Cyg, and V2107 Cyg

    SciTech Connect

    Bakış, V.; Bakış, H.; Hensberge, H.; Bilir, S.; Yılmaz, F.; Kıran, E.; Demircan, O.; Zejda, M.; Mikulášek, Z.

    2014-06-01

    Three presumably young eclipsing binary systems in the direction of the Cygnus OB1, OB3, and OB9 associations are studied. Component spectra are reconstructed and their orbits are determined using light curves and spectra disentangling techniques. V443 Cyg and V456 Cyg have circular orbits while the light curve of V2107 Cyg imposes a slightly eccentric orbit (e = 0.045 ± 0.03). V443 Cyg harbors F-type stars, not young early-A stars as previously suggested in the literature based solely on photometry. It appears to be situated in the foreground (distance 0.6 ± 0.2 kpc) of the young stellar populations in Cygnus. V456 Cyg, at a distance of 0.50 ± 0.03 kpc, consists of a slightly metal-weak A-type star and an early-F star. The age of both systems, on or very near to the main sequence, remains uncertain by an order of magnitude. V2107 Cyg is a more massive system (8.9 ± 2 and 4.5 ± 1.2 M {sub ☉}) at 1.5 ± 0.5 kpc and, also kinematically, a strong candidate-member of Cyg OB1. The more massive component is slightly evolved and appears to undergo non-radial βCep-type pulsations. The Doppler signal of the secondary is barely detectable. A more extensive, asteroseismological study is necessary to fix masses more precisely. Nevertheless, the position of the primary in the H-R diagram confines the age reasonably well to 20 ± 5 Myr, indicating that for Cyg OB1 has a similar extent of star formation history as that established for Cyg OB2.

  7. Synergies between spectroscopic and asteroseismic surveys

    NASA Astrophysics Data System (ADS)

    Fu, Jianning; De Cat, Peter; Ren, An-Bing; Yang, Xiao-Hu; Catanzaro, Giovanni; Corbally, Christopher J.; Frasca, Antonio; Gray, Richard O.; Cecylia Molenda-Zakowicz, Joanna; Shi, Jian-Rong; Ali, Luo; Zhang, Haotong

    2015-08-01

    The NASA Kepler satellite has provided unprecedented high duty-cycle, high-precision light curves for a large number of stars by continuously monitoring a field of view in Cygnus-Lyra region, leading to great progress in both discovering exoplanets and characterizing planet-hosting stars by means of asteroseismic methods. The asteroseismic survey allows the investigation of stars covering the whole H-R diagram. However, the low precision of effective temperatures and surface gravities in the KIC10 catalogue and the lack of information on chemical composition, metallicity and rotation rate prevent asteroseismic modeling, requiring spectroscopic observations for thousands of asteroseismic targets in the Kepler field in a homogeneous way.In 2010, we initiated the LAMOST-Kepler project which aimed at collecting low-resolution spectra for as many objects from the KIC10 catalogue as possible, with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), a 4-m telescope equipped with 4,000 optical fibers. The first round of observations has been completed in fall 2014, covering all the 14 sub-fields at least once, resulting in more than 100,000 low-resolution spectra. The stellar atmospheric parameters are then derived and the results have been confirmed to be consistent with those reported in the literature based on high-resolution spectroscopy.

  8. The VERITAS Sky Survey Results and Future Plans

    NASA Astrophysics Data System (ADS)

    Popkow, Alexis; Ong, R. A.; VERITAS Collaboration

    2013-01-01

    VERITAS (Very Energetic Radiation Imaging Telescope Array System) if an array of four 12 m diameter Imaging Atmospheric Cherenkov Telescopes (IACTs) located at Mt Hopkin, AZ. From 2007 to 2009 the VERITAS observatory undertook an extensive survey of the Cygnus region from 67 to 82 degrees Galactic longitude and from -1 to 4 degrees in Galactic latitude. This is a region with many promising Very High Energy (VHE) gamma-ray emitters such as supernova remnants, pulsar wind nebulae, high mass X-ray binaries and massive star clusters. In addition, the region contains several previously detected VHE gamma-ray sources and many GeV gamma-ray sources. The survey consisted of more than 140 hours of observations, reaching an average point source sensitivity of better than 4% Crab Nebula flux at energies above 200 GeV. The blind search plus follow-up observations yielded two source detections and suggested possible VHE gamma-ray emission at several other locations. Presented here are the results of a cross correlation of the VERITAS data with Fermi LAT data in the survey region.

  9. The Broad Iron K-alpha line of Cygnus X-1 as Seen by XMM-Newton in the EPIC-pn Modified Timing Mode

    NASA Technical Reports Server (NTRS)

    Duro, Refiz; Dauser, Thomas; Wilms, Jorn; Pottschmidt, Katja; Nowak, Michael A.; Fritz, Sonja; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Reynolds, Christopher S.; Staubert, Rudiger

    2011-01-01

    We present the analysis of the broadened, flourescent iron K(alpha) line in simultaneous XMM-Newton and RXTE data from the black hole Cygnus X-I. The XMM-Newton data were taken in a modified version of the Timing Mode of the EPIC-pn camera. In this mode the lower energy threshold of the instrument is increased to 2.8 keV to avoid telemetry drop outs due to the brightness of the source, while at the same time preserving the signal to noise ratio in the Fe K(alpha) band. We find that the best-fit spectrum consists of the sum of an exponentially cut-off power-law and relativistically smeared, ionized reflection. The shape of the broadened Fe K(alpha) feature is due to strong Compton broadening combined with relativistic broadening. Assuming a standard, thin accretion disk, the black hole is close to maximally rotating. Key words. X-rays: binaries - black hole physics - gravitation

  10. Probing the Inflow/Outflow and Accretion Disk of Cygnus X-1 in the High State with the Chandra High Energy Transmission Grating

    NASA Technical Reports Server (NTRS)

    Feng, Y. X.; Tennant, A. F.; Zhang, S. N.

    2003-01-01

    Cygnus X-1 was observed in the high state at the conjunction orbital phase (0) with Chandra High Energy Transmission Grating (HETG). Strong and asymmetric absorption lines of highly ionized species were detected, such as Fe xxv, Fe xxiv, Fe xxiii, Si xiv, S xvi, Ne x, etc. In the high state the profile of the absorption lines is composed of an extended red wing and a less extended blue wing. The red wings of higher ionized species are more extended than those of lower ionized species. The detection of these lines provides a way to probe the properties of the flow around the companion and the black hole in Cyg X-1 during the high state. A broad emission feature around 6.5 keV was significantly detected from the spectra of both the Chandra/HETG and the RXTE/Proportional Counter Array. This feature appears to be symmetric and can be fitted with a Gaussian function rather than the Laor disk line model of the fluorescent Fe K(alpha) line from an accretion disk. The implications of these results on the structure of the accretion flow of Cyg X-1 in the high state are discussed.

  11. NEAR-INFRARED PERIODIC AND OTHER VARIABLE FIELD STARS IN THE FIELD OF THE CYGNUS OB7 STAR-FORMING REGION

    SciTech Connect

    Wolk, Scott J.; Rice, Thomas S.; Aspin, Colin A.

    2013-04-15

    We present a subset of the results of a three-season, 124 night, near-infrared monitoring campaign of the dark clouds Lynds 1003 and Lynds 1004 in the Cygnus OB7 star-forming region. In this paper, we focus on the field star population. Using three seasons of UKIRT J, H, and K-band observations spanning 1.5 years, we obtained high-quality photometry on 9200 stars down to J = 17 mag, with photometric uncertainty better than 0.04 mag. After excluding known disk-bearing stars we identify 149 variables-1.6% of the sample. Of these, about 60 are strictly periodic, with periods predominantly <2 days. We conclude this group is dominated by eclipsing binaries. A few stars have long period signals of between 20 and 60 days. About 25 stars have weak modulated signals, but it was not clear if these were periodic. Some of the stars in this group may be diskless young stellar objects with relatively large variability due to cool starspots. The remaining {approx}60 stars showed variations which appear to be purely stochastic.

  12. RXTE Observation of Cygnus X-1: III. Implications for Compton Corona and ADAF Models. Report 3; Implications for Compton Corona and ADAF Models

    NASA Technical Reports Server (NTRS)

    Nowak, Michael A.; Wilms, Joern; Vaughan, Brian A.; Dove, James B.; Begelman, Mitchell C.

    1999-01-01

    We have recently shown that a 'sphere + disk' geometry Compton corona model provides a good description of Rossi X-ray Timing Explorer (RXTE) observations of the hard/low state of Cygnus X-1. Separately, we have analyzed the temporal data provided by RXTE. In this paper we consider the implications of this timing analysis for our best-fit 'sphere + disk' Comptonization models. We focus our attention on the observed Fourier frequency-dependent time delays between hard and soft photons. We consider whether the observed time delays are: created in the disk but are merely reprocessed by the corona; created by differences between the hard and soft photon diffusion times in coronae with extremely large radii; or are due to 'propagation' of disturbances through the corona. We find that the time delays are most likely created directly within the corona; however, it is currently uncertain which specific model is the most likely explanation. Models that posit a large coronal radius [or equivalently, a large Advection Dominated Accretion Flow (ADAF) region] do not fully address all the details of the observed spectrum. The Compton corona models that do address the full spectrum do not contain dynamical information. We show, however, that simple phenomenological propagation models for the observed time delays for these latter models imply extremely slow characteristic propagation speeds within the coronal region.

  13. Changes in lipid and fatty acid composition of late larval and puerulus stages of the spiny lobster (Panulirus cygnus) across the continental shelf of Western Australia.

    PubMed

    Phillips, Bruce F; Jeffs, Andrew G; Melville-Smith, Roy; Chubb, Chris F; Nelson, Matthew M; Nichols, Peter D

    2006-02-01

    The feeding of the late larval stages of the spiny lobster, Panulirus cygnus, and the energy reserves used by the non-feeding post-larvae for crossing the continental shelf of Western Australia were examined through their lipid composition. Lipid was a significant component of the biomass of all larval and post-larval samples (range 63-213 mg g(-1) of dry biomass). The fatty acid profiles of late stage larvae (8-9) suggest that they were feeding on salps and small crustaceans, such as euphausids, from oligotrophic pelagic communities where herbivorous and microbial grazing is an important basis to the food web. There was a marked decrease in lipid content of post-larvae progressively across the continental shelf, and this corresponded closely with decreasing dry mass, suggesting that post-larvae were using lipid as an energy source during cross-shelf movement at a rate of 1.6 J km(-1). This is considerably lower than for other spiny lobster species, suggesting that the post-larvae of the western rock lobster may use physical processes as well as active swimming for onshore transport. This may help to explain the large inter-annual variability in the post-larval settlement of this species, which is closely related to differences in weather patterns capable of greatly varying onshore advection processes.

  14. TIMING AND INTERSTELLAR SCATTERING OF 35 DISTANT PULSARS DISCOVERED IN THE PALFA SURVEY

    SciTech Connect

    Nice, D. J.; Altiere, E.; Farrington, D.; Popa, L.; Wang, Y.; Bogdanov, S.; Camilo, F.; Cordes, J. M.; Brazier, A.; Chatterjee, S.; Hessels, J. W. T.; Kaspi, V. M.; Lyne, A. G.; Stappers, B. W.; Ransom, S. M.; Sanpa-arsa, S.; Allen, B.; Bhat, N. D. R.; Champion, D. J.; Crawford, F.; and others

    2013-07-20

    We have made extensive observations of 35 distant slow (non-recycled) pulsars discovered in the ongoing Arecibo PALFA pulsar survey. Timing observations of these pulsars over several years at Arecibo Observatory and Jodrell Bank Observatory have yielded high-precision positions and measurements of rotation properties. Despite being a relatively distant population, these pulsars have properties that mirror those of the previously known pulsar population. Many of the sources exhibit timing noise, and one underwent a small glitch. We have used multifrequency data to measure the interstellar scattering properties of these pulsars. We find scattering to be higher than predicted along some lines of sight, particularly in the Cygnus region. Finally, we present XMM-Newton and Chandra observations of the youngest and most energetic of the pulsars, J1856+0245, which has previously been associated with the GeV-TeV pulsar wind nebula HESS J1857+026.

  15. MAXI observations of long-term variations of Cygnus X-1 in the low/hard and the high/soft states

    NASA Astrophysics Data System (ADS)

    Sugimoto, Juri; Mihara, Tatehiro; Kitamoto, Shunji; Matsuoka, Masaru; Sugizaki, Mutsumi; Negoro, Hitoshi; Nakahira, Satoshi; Makishima, Kazuo

    2016-06-01

    The long-term X-ray variability of the black hole binary Cygnus X-1 was studied with five years of MAXI data from 2009 to 2014, which include substantial periods of the high/soft state, as well as the low/hard state. In each state, normalized power spectrum densities (NPSDs) were calculated in three energy bands of 2-4 keV, 4-10 keV, and 10-20 keV. The NPSDs for frequencies from 10-7 Hz to 10-4 Hz are all approximated by a power-law function with an index -1.35-1.29. The fractional RMS variation η, calculated in the above frequency range, was found to show the following three properties: (1) η slightly decreases with energy in the low/hard state; (2) η increases towards higher energies in the high/soft state; and (3) in the 10-20 keV band, η is three times higher in the high/soft state than in the low/hard state. These properties were confirmed through studies of intensity-correlated changes of the MAXI spectra. Of these three findings, the first one is consistent with that seen in the short-term variability during the low/hard state. The latter two can be understood as a result of high variability of the hard-tail component seen in the high/soft state with the above very low frequency range, although the origin of the variability remains inconclusive.

  16. Chandra X-ray Spectroscopy of the Focused Wind In the Cygnus X-1 System I. The Non-Dip Spectrum in the Low/Hard State

    NASA Technical Reports Server (NTRS)

    Hanke, Manfred; Wilms, Jorn; Nowak, Michael A.; Pottschmidt, Katja; Schultz, Norbert S.; Lee, Julia C.

    2008-01-01

    We present analyses of a 50 ks observation of the supergiant X-ray binary system CygnusX-1/HDE226868 taken with the Chandra High Energy Transmission Grating Spectrometer (HETGS). CygX-1 was in its spectrally hard state and the observation was performed during superior conjunction of the black hole, allowing for the spectroscopic analysis of the accreted stellar wind along the line of sight. A significant part of the observation covers X-ray dips as commonly observed for CygX-1 at this orbital phase, however, here we only analyze the high count rate non-dip spectrum. The full 0.5-10 keV continuum can be described by a single model consisting of a disk, a narrow and a relativistically broadened Fe K line, and a power law component, which is consistent with simultaneous RXTE broad band data. We detect absorption edges from overabundant neutral O, Ne and Fe, and absorption line series from highly ionized ions and infer column densities and Doppler shifts. With emission lines of He-like Mg XI, we detect two plasma components with velocities and densities consistent with the base of the spherical wind and a focused wind. A simple simulation of the photoionization zone suggests that large parts of the spherical wind outside of the focused stream are completely ionized, which is consistent with the low velocities (<200 km/s) observed in the absorption lines, as the position of absorbers in a spherical wind at low projected velocity is well constrained. Our observations provide input for models that couple the wind activity of HDE 226868 to the properties of the accretion flow onto the black hole.

  17. Fatty acid profiles of phyllosoma larvae of western rock lobster (Panulirus cygnus) in cyclonic and anticyclonic eddies of the Leeuwin Current off Western Australia

    NASA Astrophysics Data System (ADS)

    Wang, M.; O'Rorke, R.; Waite, A. M.; Beckley, L. E.; Thompson, P.; Jeffs, A. G.

    2014-03-01

    The recent dramatic decline in settlement in the population of the spiny lobster, Panulirus cygnus, may be due to changes in the oceanographic processes that operate offshore of Western Australia. It has been suggested that this decline could be related to poor nutritional condition of the post-larvae, especially lipid which is accumulated in large quantities during the preceding extensive pelagic larval stage. The current study focused on investigations into the lipid content and fatty acid (FA) profiles of lobster phyllosoma larvae from three mid to late stages of larval development (stages VI, VII, VIII) sampled from two cyclonic and two anticyclonic eddies of the Leeuwin Current off Western Australia. The results showed significant accumulation of lipid and energy storage FAs with larval development regardless of location of capture, however, larvae from cyclonic eddies had more lipid and FAs associated with energy storage than larvae from anticyclonic eddies. FA food chain markers from the larvae indicated significant differences in the food webs operating in the two types of eddy, with a higher level of FA markers for production from flagellates and a lower level from copepod grazing in cyclonic versus anticyclonic eddies. The results indicate that the microbial food web operating in cyclonic eddies provides better feeding conditions for lobster larvae despite anticyclonic eddies being generally more productive and containing greater abundances of zooplankton as potential prey for lobster larvae. Gelatinous zooplankton, such as siphonophores, may play an important role in cyclonic eddies by accumulating dispersed microbial nutrients and making them available as larger prey for phyllosoma. The markedly superior nutritional condition of lobster larvae feeding in the microbial food web found in cyclonic eddies, could greatly influence their subsequent settlement and recruitment to the coastal fishery.

  18. A New Method to Resolve X-Ray Halos around Point Sources with Chandra Data and Its Application to Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Yao, Yangsen; Zhang, Shuang Nan; Zhang, Xiao-Ling; Feng, Yu-Xin

    2003-01-01

    With excellent angular resolution, good energy resolution, and a broad energy band, the Chandra Advanced CCD Imaging Spectrometer (ACIS) is the best instrument for studying the X-ray halos around some Galactic X-ray point sources caused by the dust scattering of X-rays in the interstellar medium. However, the direct images of bright sources obtained with the ACIS usually suffer from severe pileup. Making use of the fact that an isotropic image could be reconstructed from its projection in to any direction, we can reconstruct the images of the X-ray halos from the data obtained with the High Energy Transition Grating Spectrometer (HETGS) and/or in continuos clocking (CC) mode. These data have no or less serious pileup and enable us to take full advantage of the excellent angular resolution of Chandra. With the reconstructed high-resolution images, we can probe the X-ray halos as close as 1" to their associated point sources. Applying this method to Cygnus X-1 observed with the Chandra HETGS in CC mode, we derived an energy-dependent radial halo flux distribution and concluded that in a circular region (2' in radius) centered a the point source: (1) relative to the total intensity, the fractional halo intensity is about 15% at keV and drops to aboout 5% at approximately 6 keV (2) about 50% of the halo photons are within the region of a radius less than 40 inches and (3) the spectrum of the pooint source is slightly distorted by the halo contamination.

  19. Survey Says

    ERIC Educational Resources Information Center

    McCarthy, Susan K.

    2005-01-01

    Survey Says is a lesson plan designed to teach college students how to access Internet resources for valid data related to the sexual health of young people. Discussion questions based on the most recent available data from two national surveys, the Youth Risk Behavior Surveillance-United States, 2003 (CDC, 2004) and the National Survey of…

  20. Theory Survey or Survey Theory?

    ERIC Educational Resources Information Center

    Dean, Jodi

    2010-01-01

    Matthew Moore's survey of political theorists in U.S. American colleges and universities is an impressive contribution to political science (Moore 2010). It is the first such survey of political theory as a subfield, the response rate is very high, and the answers to the survey questions provide new information about how political theorists look…

  1. Spectrum and Morphology of the Two Brightest Milagro Sources in the Cygnus Region: MGRO J2019+37 and MGRO J2031+41

    NASA Technical Reports Server (NTRS)

    Abdo, A. A.; Abeysekara, U.; Allen, B, T.; Aune, T.; Berley, D.; Bonamente, E.; Christopher, G. E.; DeYoung, T.; Dingus, B. L.; Ellsworth, R. W.; Galbraith-Frew, J. G.; Gonzalez, M. M.; Goodman, J. A.; Hoffman, C. M.; Huentemeyer, P. H.; Hui, C. M.; Kolterman, B. E.; Linnemann, J . T.; McEnery, J. E.; Mincer, A. I.; Morgan, T.; Nemethy, P.; Pretz, J.; Ryan, J. M.; Vasileiou, V.

    2012-01-01

    The Cygnus region is a very bright and complex portion of the TeV sky, host to unidentified sources and a diffuse excess with respect to conventional cosmic-ray propagation models. Two of the brightest TeV sources, MGRO J2019+37 and MGRO J2031+41, are analyzed using Milagro data with a new technique, and their emission is tested under two different spectral assumptions: a power law and a power law with an exponential cutoff. The new analysis technique is based on an energy estimator that uses the fraction of photomultiplier tubes in the observatory that detect the extensive air shower. The photon spectrum is measured in the range 1-100 TeV using the last three years of Milagro data (2005-2008), with the detector in its final configuration. An F-test indicates that MGRO J2019+37 is better fit by a power law with an exponential cutoff than by a simple power law. The best-fitting parameters for the power law with exponential cutoff model are a normalization at 10 TeV of 7(sup +5 sub -2) × 10(exp -10)/ s /sq m/ TeV, a spectral index of 2.0(sup +0.5 sub -10), and a cutoff energy of 29(sup +50 sub -16) TeV. MGRO J2031+41 shows no evidence of a cutoff. The best-fitting parameters for a power law are a normalization of 2.1(sup +0.6 sub -0.6) × 10(exp -10)/ s/sq m/ TeV and a spectral index of 3.22(sup +0.23 sub -0.18. The overall flux is subject to a approx.. 30% systematic uncertainty. The systematic uncertainty on the power-law indices is approx. 0.1. Both uncertainties have been verified with cosmic-ray data. A comparison with previous results from TeV J2032+4130, MGRO J2031+41, and MGRO J2019+37 is also presented.

  2. INITIAL DATA RELEASE OF THE KEPLER-INT SURVEY

    SciTech Connect

    Greiss, S.; Steeghs, D.; Gaensicke, B. T.; Martin, E. L.; Groot, P. J.; Verbeek, K.; Jonker, P. G.; Scaringi, S.; Greimel, R.; Knigge, C.; Ostensen, R. H.; Drew, J. E.; Farnhill, H.; Drake, J.; Wright, N. J.; Ripepi, V.; Southworth, J.; Still, M. [NASA Ames Research Center, M and others

    2012-07-15

    This paper describes the first data release of the Kepler-INT Survey (KIS) that covers a 116 deg{sup 2} region of the Cygnus and Lyra constellations. The Kepler field is the target of the most intensive search for transiting planets to date. Despite the fact that the Kepler mission provides superior time-series photometry, with an enormous impact on all areas of stellar variability, its field lacks optical photometry complete to the confusion limit of the Kepler instrument necessary for selecting various classes of targets. For this reason, we follow the observing strategy and data reduction method used in the IPHAS and UVEX galactic plane surveys in order to produce a deep optical survey of the Kepler field. This initial release concerns data taken between 2011 May and August, using the Isaac Newton Telescope on the island of La Palma. Four broadband filters were used, U, g, r, i, as well as one narrowband one, H{alpha}, reaching down to a 10{sigma} limit of {approx}20th mag in the Vega system. Observations covering {approx}50 deg{sup 2}, thus about half of the field, passed our quality control thresholds and constitute this first data release. We derive a global photometric calibration by placing the KIS magnitudes as close as possible to the Kepler Input Catalog (KIC) photometry. The initial data release catalog containing around 6 million sources from all the good photometric fields is available for download from the KIS Web site (www.astro.warwick.ac.uk/research/kis/) as well as via MAST (KIS magnitudes can be retrieved using the MAST enhanced target search page http://archive.stsci.edu/kepler/kepler{sub f}ov/search.php and also via Casjobs at MAST Web site http://mastweb.stsci.edu/kplrcasjobs/).

  3. Multicultural Survey.

    ERIC Educational Resources Information Center

    Renyi, Judith, Comp.

    In May of 1992, the Alliance for Curriculum Reform (ACR) surveyed member organizations and others who had participated in ACR activities concerning their printed policies on issues relating to multicultural education. The areas of interest for the survey were: printed policy(ies) on multicultural content/curriculum; printed policy(ies) on student…

  4. SURVEY INSTRUMENT

    DOEpatents

    Borkowski, C J

    1954-01-19

    This pulse-type survey instrument is suitable for readily detecting {alpha} particles in the presence of high {beta} and {gamma} backgrounds. The instruments may also be used to survey for neutrons, {beta} particles and {gamma} rays by employing suitably designed interchangeable probes and selecting an operating potential to correspond to the particular probe.

  5. Surveying System

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Sunrise Geodetic Surveys are setting up their equipment for a town survey. Their equipment differs from conventional surveying systems that employ transit rod and chain to measure angles and distances. They are using ISTAC Inc.'s Model 2002 positioning system, which offers fast accurate surveying with exceptional signals from orbiting satellites. The special utility of the ISTAC Model 2002 is that it can provide positioning of the highest accuracy from Navstar PPS signals because it requires no knowledge of secret codes. It operates by comparing the frequency and time phase of a Navstar signal arriving at one ISTAC receiver with the reception of the same set of signals by another receiver. Data is computer processed and translated into three dimensional position data - latitude, longitude and elevation.

  6. Geosat survey

    NASA Astrophysics Data System (ADS)

    The Geosat Committee, a nonprofit, educational organization dedicated to improving satellite remote sensing for geological applications, is surveying the international geological community to determine the most important areas of the world for the exploration of nonrenewable resources. The results of this survey, whose sources will be kept confidential, will be given as recommendations for early satellite-scene selection to the the U.S. government (via the National Oceanic and Atmospheric Administration) and to other countries with satellites or ground receiving stations.

  7. Complexity Survey.

    ERIC Educational Resources Information Center

    Gordon, Sandra L.; Anderson, Beth C.

    To determine whether consensus existed among teachers about the complexity of common classroom materials, a survey was administered to 66 pre-service and in-service kindergarten and prekindergarten teachers. Participants were asked to rate 14 common classroom materials as simple, complex, or super-complex. Simple materials have one obvious part,…

  8. Laser Surveying

    NASA Technical Reports Server (NTRS)

    1978-01-01

    NASA technology has produced a laser-aided system for surveying land boundaries in difficult terrain. It does the job more accurately than conventional methods, takes only one-third the time normally required, and is considerably less expensive. In surveying to mark property boundaries, the objective is to establish an accurate heading between two "corner" points. This is conventionally accomplished by erecting a "range pole" at one point and sighting it from the other point through an instrument called a theodolite. But how do you take a heading between two points which are not visible to each other, for instance, when tall trees, hills or other obstacles obstruct the line of sight? That was the problem confronting the U.S. Department of Agriculture's Forest Service. The Forest Service manages 187 million acres of land in 44 states and Puerto Rico. Unfortunately, National Forest System lands are not contiguous but intermingled in complex patterns with privately-owned land. In recent years much of the private land has been undergoing development for purposes ranging from timber harvesting to vacation resorts. There is a need for precise boundary definition so that both private owners and the Forest Service can manage their properties with confidence that they are not trespassing on the other's land.

  9. Farmland Survey

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A 1981 U.S. Department of Agriculture (USDA) study estimated that the nation is converting farmland to non-agricultural uses at the rate of 3 million acres a year. Seeking information on farmland loss in Florida, the state legislature, in 1984, directed establishment of a program for development of accurate data to enable intelligent legislation of state growth management. Thus was born Florida's massive Mapping and Monitoring of Agricultural Lands Project (MMALP). It employs data from the NASA-developed Landsat Earth resources survey satellite system as a quicker, less expensive alternative to ground surveying. The 3 year project involved inventory of Florida's 36 million acres classifying such as cropland, pastureland, citrus, woodlands, wetland, water and populated areas. Direction was assigned to Florida Department of Community Affairs (DCA) with assistance from the DOT. With the cooperation of the USDA, Soil Conservation Service, DCA decided that combining soil data with the Landsat land cover data would make available to land use planners a more comprehensive view of a county's land potential.

  10. Chandra X-ray spectroscopy of focused wind in the Cygnus X-1 system. II. The non-dip spectrum in the low/hard state - modulations with orbital phase

    NASA Astrophysics Data System (ADS)

    Miškovičová, Ivica; Hell, Natalie; Hanke, Manfred; Nowak, Michael A.; Pottschmidt, Katja; Schulz, Norbert S.; Grinberg, Victoria; Duro, Refiz; Madej, Oliwia K.; Lohfink, Anne M.; Rodriguez, Jérôme; Cadolle Bel, Marion; Bodaghee, Arash; Tomsick, John A.; Lee, Julia C.; Brown, Gregory V.; Wilms, Jörn

    2016-05-01

    Accretion onto the black hole in the system HDE 226868/Cygnus X-1 is powered by the strong line-driven stellar wind of the O-type donor star. We study the X-ray properties of the stellar wind in the hard state of Cyg X-1, as determined using data from the Chandra High Energy Transmission Gratings. Large density and temperature inhomogeneities are present in the wind, with a fraction of the wind consisting of clumps of matter with higher density and lower temperature embedded in a photoionized gas. Absorption dips observed in the light curve are believed to be caused by these clumps. This work concentrates on the non-dip spectra as a function of orbital phase. The spectra show lines of H-like and He-like ions of S, Si, Na, Mg, Al, and highly ionized Fe (Fe xvii-Fe xxiv). We measure velocity shifts, column densities, and thermal broadening of the line series. The excellent quality of these five observations allows us to investigate the orbital phase-dependence of these parameters. We show that the absorber is located close to the black hole. Doppler shifted lines point at a complex wind structure in this region, while emission lines seen in some observations are from a denser medium than the absorber. The observed line profiles are phase-dependent. Their shapes vary from pure, symmetric absorption at the superior conjunction to P Cygni profiles at the inferior conjunction of the black hole.

  11. Infrastructure Survey 2011

    ERIC Educational Resources Information Center

    Group of Eight (NJ1), 2012

    2012-01-01

    In 2011, the Group of Eight (Go8) conducted a survey on the state of its buildings and infrastructure. The survey is the third Go8 Infrastructure survey, with previous surveys being conducted in 2007 and 2009. The current survey updated some of the information collected in the previous surveys. It also collated data related to aspects of the…

  12. Robotic Surveying

    SciTech Connect

    Suzy Cantor-McKinney; Michael Kruzic

    2007-03-01

    -actuated functions to be controlled by an onboard computer. The computer-controlled Speedrower was developed at Carnegie Mellon University to automate agricultural harvesting. Harvesting tasks require the vehicle to cover a field using minimally overlapping rows at slow speeds in a similar manner to geophysical data acquisition. The Speedrower had demonstrated its ability to perform as it had already logged hundreds of acres of autonomous harvesting. This project is the first use of autonomous robotic technology on a large-scale for geophysical surveying.

  13. Alumni Perspectives Survey, 2010. Survey Report

    ERIC Educational Resources Information Center

    Sheikh, Sabeen

    2010-01-01

    During the months of April and September of 2009, the Graduate Management Admission Council[R] (GMAC[R]) conducted the Alumni Perspectives Survey, a longitudinal study of prior respondents to the Global Management Education Graduate Survey of management students nearing graduation. A total of 3,708 alumni responded to the April 2009 survey,…

  14. 2012 Alumni Perspectives Survey. Survey Report

    ERIC Educational Resources Information Center

    Leach, Laura

    2012-01-01

    Conducted in September 2011, this Alumni Perspectives Survey by the Graduate Management Admission Council (GMAC) is a longitudinal study of respondents to the Global Management Education Graduate Survey, the annual GMAC[R] exit survey of graduate management students in their final year of business school. This 12th annual report includes responses…

  15. A Northern Sky Survey for Point-like Sources of EeV Neutral Particles with the Telescope Array Experiment

    NASA Astrophysics Data System (ADS)

    Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

    2015-05-01

    We report on the search for steady point-like sources of neutral particles around 1018 eV between 2008 and 2013 May with the scintillator SD of the Telescope Array experiment. We found overall no significant point-like excess above 0.5 EeV in the northern sky. Subsequently, we also searched for coincidence with the Fermi bright Galactic sources. No significant coincidence was found within the statistical uncertainty. Hence, we set an upper limit on the neutron flux that corresponds to an averaged flux of 0.07 km-2 yr-1 for E\\gt 1 EeV in the northern sky at the 95% confidence level. This is the most stringent flux upper limit in a northern sky survey assuming point-like sources. The upper limit at the 95% confidence level on the neutron flux from Cygnus X-3 is also set to 0.2 km-2 yr-1 for E\\gt 0.5 EeV. This is an order of magnitude lower than previous flux measurements.

  16. Community Perception Survey, 2001.

    ERIC Educational Resources Information Center

    Rasmussen, Patricia; Silverman, Barbara

    This document is a report on the 2001 Community Perception Survey administered by Mt. San Antonio College (SAC) (California). The survey gathered public perception data of SAC services and programs. The survey was mailed to 773 service area community leaders; 160 (21%) responded. Survey results showed that: (1) 70% had knowledge of SAC programs…

  17. ACSI Survey 2014

    Atmospheric Science Data Center

    2014-08-26

    Upcoming EOSDIS Survey   Dear Colleagues,   In the next few days, you will ... on behalf of NASA. This message will ask you to complete a survey for users of NASA Earth science data and services, which includes the ... System (EOSDIS) science data centers evaluated by this survey. The purpose of this survey is to help NASA and the DAACs assess ...

  18. The AAS Workforce Survey

    NASA Astrophysics Data System (ADS)

    Postman, Marc; Norman, D. J.; Evans, N. R.; Ivie, R.

    2014-01-01

    The AAS Demographics Committee, on behalf of the AAS, was tasked with initiating a biennial survey to improve the Society's ability to serve its members and to inform the community about changes in the community's demographics. A survey, based in part on similar surveys for other scientific societies, was developed in the summer of 2012 and was publicly launched in January 2013. The survey randomly targeted 2500 astronomers who are members of the AAS. The survey was closed 4 months later (April 2013). The response rate was excellent - 63% (1583 people) completed the survey. I will summarize the results from this survey, highlighting key results and plans for their broad dissemination.

  19. Corporate Recruiters Survey, 2011. Survey Report

    ERIC Educational Resources Information Center

    Edgington, Rachel

    2011-01-01

    In this report, the Graduate Management Admission Council[R] (GMAC[R]) presents the results from the 2011 Corporate Recruiters Survey. Conducted annually since 2001, this survey examines the job outlook for recent graduate business students as well as employer needs and expectations. The objectives of this study are to obtain a picture of the…

  20. 2012 Corporate Recruiters Survey. Survey Report

    ERIC Educational Resources Information Center

    Estrada, Rebecca

    2012-01-01

    This paper presents the results from the 2012 Corporate Recruiters Survey conducted by the Graduate Management Admission Council[R] (GMAC[R]). Conducted annually since 2001, this survey examines the job outlook for recent graduate business students as well as employer needs and expectations. The objectives of this study are to obtain a picture of…

  1. High resolution survey for topographic surveying

    NASA Astrophysics Data System (ADS)

    Luh, L. C.; Setan, H.; Majid, Z.; Chong, A. K.; Tan, Z.

    2014-02-01

    In this decade, terrestrial laser scanner (TLS) is getting popular in many fields such as reconstruction, monitoring, surveying, as-built of facilities, archaeology, and topographic surveying. This is due the high speed in data collection which is about 50,000 to 1,000,000 three-dimensional (3D) points per second at high accuracy. The main advantage of 3D representation for the data is that it is more approximate to the real world. Therefore, the aim of this paper is to show the use of High-Definition Surveying (HDS), also known as 3D laser scanning for topographic survey. This research investigates the effectiveness of using terrestrial laser scanning system for topographic survey by carrying out field test in Universiti Teknologi Malaysia (UTM), Skudai, Johor. The 3D laser scanner used in this study is a Leica ScanStation C10. Data acquisition was carried out by applying the traversing method. In this study, the result for the topographic survey is under 1st class survey. At the completion of this study, a standard of procedure was proposed for topographic data acquisition using laser scanning systems. This proposed procedure serves as a guideline for users who wish to utilize laser scanning system in topographic survey fully.

  2. Aerial radiation surveys

    SciTech Connect

    Jobst, J.

    1980-01-01

    A recent aerial radiation survey of the surroundings of the Vitro mill in Salt Lake City shows that uranium mill tailings have been removed to many locations outside their original boundary. To date, 52 remote sites have been discovered within a 100 square kilometer aerial survey perimeter surrounding the mill; 9 of these were discovered with the recent aerial survey map. Five additional sites, also discovered by aerial survey, contained uranium ore, milling equipment, or radioactive slag. Because of the success of this survey, plans are being made to extend the aerial survey program to other parts of the Salt Lake valley where diversions of Vitro tailings are also known to exist.

  3. Water Use: A Survey

    ERIC Educational Resources Information Center

    Fleming, Rose Glee; Warden, Jessie

    1976-01-01

    A survey of Florida State University students showed that their current laundry practices generate energy and water over-consumption. The survey also resulted in some concrete suggestions to the students that would improve their conservation practices. (Author/BP)

  4. National Health Care Survey

    Cancer.gov

    This survey encompasses a family of health care provider surveys, including information about the facilities that supply health care, the services rendered, and the characteristics of the patients served.

  5. Telephone Survey Designs.

    ERIC Educational Resources Information Center

    Casady, Robert J.

    The concepts, definitions, and notation that have evolved with the development of telephone survey design methodology are discussed and presented as a unified structure. This structure is then applied to some of the more well-known telephone survey designs and alternative designs are developed. The relative merits of the different survey designs…

  6. AECT Needs Survey, 2000.

    ERIC Educational Resources Information Center

    Frick, Theodore W.; Richter, Kurt; Kim, Minhee; Yang, Jessica Chao-I; Duvenci, Abdullah

    The purpose of this study was to determine the needs of AECT (Association for Educational Communications and Technology) members. A total of 590 individuals completed a Web-based 16-question survey after receiving an e-mail invitation from AECT. This survey was active between October 30 and November 10, 2000. The survey was categorized into three…

  7. Sensitive Questions in Surveys

    ERIC Educational Resources Information Center

    Tourangeau, Roger; Yan, Ting

    2007-01-01

    Psychologists have worried about the distortions introduced into standardized personality measures by social desirability bias. Survey researchers have had similar concerns about the accuracy of survey reports about such topics as illicit drug use, abortion, and sexual behavior. The article reviews the research done by survey methodologists on…

  8. Environmental Survey preliminary report

    SciTech Connect

    Not Available

    1988-04-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the United States Department of Energy (DOE) Sandia National Laboratories conducted August 17 through September 4, 1987. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with Sandia National Laboratories-Albuquerque (SNLA). The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at SNLA, and interviews with site personnel. 85 refs., 49 figs., 48 tabs.

  9. Developing the online survey.

    PubMed

    Gordon, Jeffry S; McNew, Ryan

    2008-12-01

    Institutions of higher education are now using Internet-based technology tools to conduct surveys for data collection. Research shows that the type and quality of responses one receives with online surveys are comparable with what one receives in paper-based surveys. Data collection can take place on Web-based surveys, e-mail-based surveys, and personal digital assistants/Smartphone devices. Web surveys can be subscription templates, software packages installed on one's own server, or created from scratch using Web programming development tools. All of these approaches have their advantages and disadvantages. The survey owner must make informed decisions as to the right technology to implement. The correct choice can save hours of work in sorting, organizing, and analyzing data.

  10. ESO imaging survey: infrared deep public survey

    NASA Astrophysics Data System (ADS)

    Olsen, L. F.; Miralles, J.-M.; da Costa, L.; Madejsky, R.; Jørgensen, H. E.; Mignano, A.; Arnouts, S.; Benoist, C.; Dietrich, J. P.; Slijkhuis, R.; Zaggia, S.

    2006-09-01

    This paper is part of the series presenting the final results obtained by the ESO Imaging Survey (EIS) project. It presents new J and Ks data obtained from observations conducted at the ESO 3.5 m New Technology Telescope (NTT) using the SOFI camera. These data were taken as part of the Deep Public Survey (DPS) carried out by the ESO Imaging Survey program, significantly extending the earlier optical/infrared EIS-DEEP survey presented in a previous paper of this series. The DPS-IR survey comprises two observing strategies: shallow Ks observations providing nearly full coverage of pointings with complementary multi-band (in general {UBVRI}) optical data obtained using ESO's wide-field imager (WFI) and deeper J and Ks observations of the central parts of these fields. Currently, the DPS-IR survey provides a coverage of roughly 2.1 square degrees ( 300 SOFI pointings) in Ks with 0.63 square degrees to fainter magnitudes and also covered in J, over three independent regions of the sky. The goal of the present paper is to briefly describe the observations, the data reduction procedures, and to present the final survey products which include fully calibrated pixel-maps and catalogs extracted from them. The astrometric solution with an estimated accuracy of ⪉0.15 arcsec is based on the USNO catalog and limited only by the accuracy of the reference catalog. The final stacked images presented here number 89 and 272, in J and K_s, respectively, the latter reflecting the larger surveyed area. The J and Ks images were taken with a median seeing of 0.77 arcsec and 0.8 arcsec. The images reach a median 5σ limiting magnitude of JAB˜23.06 as measured within an aperture of 2´´, while the corresponding limiting magnitude in KsAB is 21.41 and 22.16 mag for the shallow and deep strategies. Although some spatial variation due to varying observing conditions is observed, overall the observed limiting magnitudes are consistent with those originally proposed. The quality of the data

  11. Atmospheric prediction model survey

    NASA Technical Reports Server (NTRS)

    Wellck, R. E.

    1976-01-01

    As part of the SEASAT Satellite program of NASA, a survey of representative primitive equation atmospheric prediction models that exist in the world today was written for the Jet Propulsion Laboratory. Seventeen models developed by eleven different operational and research centers throughout the world are included in the survey. The surveys are tutorial in nature describing the features of the various models in a systematic manner.

  12. Application Trends Survey. 2014 Survey Report

    ERIC Educational Resources Information Center

    Worthington, Rebecca; Bruggeman, Paula

    2014-01-01

    Now in its 15th year, the Graduate Management Admission Council's assessment of application volume trends for graduate management programs offers timely insights into demographic shifts and other factors defining the candidate pools for the 2014 application cycle. Responses collected in the 2014 survey represent a record-breaking total of 748 MBA,…

  13. Corporate Recruiters Survey: 2014 Survey Report

    ERIC Educational Resources Information Center

    Estrada Worthington, Rebecca

    2014-01-01

    The 2014 Corporate Recruiters Survey Report examines the current hiring outlook for graduate business students and analyzes demand by industry and world region, salaries, job functions, and mobility in regional job placement. It also explores recruiter behavior, including recruitment practices and school and candidate selection criteria, and…

  14. Application Trends Survey, 2011. Survey Report

    ERIC Educational Resources Information Center

    Estrada, Rebecca

    2011-01-01

    The 2011 Application Trends Survey conducted by the Graduate Management Admission Council (GMAC) is the industry source for comprehensive statistics and timely and reliable insights into the demand for graduate management education around the world. A total of 649 programs from 331 business schools and faculties worldwide representing 45 countries…

  15. Alumni Perspectives Survey, 2011. Survey Report

    ERIC Educational Resources Information Center

    Sheikh, Sabeen

    2011-01-01

    Since the Graduate Management Admission Council[R] (GMAC[R]) first began conducting its Alumni Perspectives Surveys 11 years ago, several "truths" about graduate business school alumni have consistently stood the test of time: They are and remain eminently employable. They constantly rate the value of the degree highly. This year's results are…

  16. Alumni Perspectives Survey. 2014 Survey Report

    ERIC Educational Resources Information Center

    Schoenfeld, Gregg

    2014-01-01

    Alumni are a powerful force in building a business school's brand. They recommend programs to prospective students, they connect current students to job opportunities, and they contribute significantly to building a school's legacy. The findings in the 2014 Alumni Perspectives Survey Report provide a current snapshot of nearly 21,000 business…

  17. Mortality in tundra swans Cygnus columbianus

    USGS Publications Warehouse

    Bartonek, J.C.; Serie, J.R.; Converse, K.A.

    1991-01-01

    Our paper identifies and examines the significance of hunting and non-hunting mortality affecting the Eastern Population (EP) and Western Population (WP) (see Serie & Bartonek 1991a) of Tundra Swans. Sport hunting (Serie & Bartonek 1991b), native subsistence hunting (Copp 1989, Stewart & Bernier 1989), malicious shooting (McKelvey & MacNeill 1981), avian cholera (Friend et al. 1981, Schroeder 1983), ecto- and endoparasites (Trauger & Bartonek 1977, Woebeser 1981), lead poisoning (Sherwood 1960, Friend et al. 1981), collision (Willard 1978), and drowning (Miller et al. 1986) have been documented as being direct or indirect causes of mortality in fledged Tundra Swans; but their relative importance remains unknown.

  18. Infrastructure Survey 2009

    ERIC Educational Resources Information Center

    Group of Eight (NJ1), 2010

    2010-01-01

    In 2008 the Group of Eight (Go8) released a first report on the state of its buildings and infrastructure, based on a survey undertaken in 2007. A further survey was undertaken in 2009, updating some information about the assessed quality, value and condition of buildings and use of space. It also collated data related to aspects of the estate not…

  19. Seven Survey Sins

    ERIC Educational Resources Information Center

    Gehlbach, Hunter

    2015-01-01

    As pressure builds to assess students, teachers, and schools, educational practitioners and policy makers are increasingly looking toward student perception surveys as a promising means to collect high-quality, useful data. For instance, the widely cited Measures of Effective Teaching study lists student perception surveys as one of the three key…

  20. Basic Surveying Technology.

    ERIC Educational Resources Information Center

    Olson, David A.; Kellum, Mary, Ed.

    This document is intended to help teachers prepare students to perform the duties of any member of a surveying party, including those of party chief, in the field and in the office. It contains instructional units on introduction to surveying, safety, horizontal measurements, vertical measurements, angles and directions, angular measurements,…

  1. Leaver Survey Report, 1996.

    ERIC Educational Resources Information Center

    Cunningham, Stephen

    To determine factors influencing attrition and retention at Pennsylvania College of Technology, a survey was conducted of the 688 students who were enrolled in spring 1996 but neither graduated nor enrolled in fall 1996. Responses were received from 437 former students and were compared to findings from a similar survey of 482 leavers in 1994.…

  2. Submarine cable route survey

    SciTech Connect

    Herrouin, G.; Scuiller, T.

    1995-12-31

    The growth of telecommunication market is very significant. From the beginning of the nineties, more and more the use of optical fiber submarine cables is privileged to that of satellites. These submarine telecommunication highways require accurate surveys in order to select the optimum route and determine the cable characteristics. Advanced technology tools used for these surveys are presented along with their implementation.

  3. Freshman Survey Report, 1997.

    ERIC Educational Resources Information Center

    Cunningham, Steve; Hiris, Eric

    The Cooperative Institutional Research Program (CIRP) sponsors a national annual survey that gathers data on incoming freshman classes at two- and four-year institutions. The data allow the colleges to compare their students with previous classes and with the "average" American freshman. This report presents findings from the 1997 CIRP survey at…

  4. And the Survey Says...

    ERIC Educational Resources Information Center

    White, Susan C.

    2016-01-01

    Last month we highlighted our Quadrennial Survey of High School Physics Teachers. Using data from the survey, we have looked at the availability of high school physics. We report that about 95% of high school seniors attend a high school where physics is offered regularly--either every year or every other year. A U.S. Department of Education…

  5. Maryland Adolescent Survey, 1994.

    ERIC Educational Resources Information Center

    Maryland State Dept. of Education, Baltimore. Div. of Compensatory Education and Support Services.

    This report details the latest findings from the biennial Maryland Adolescent Survey of the extent and trends in alcohol, tobacco, and drug use among students. To permit comparisons with national findings and trends, the form and content of survey items parallel those of the annual national study "Monitoring the Future," conducted by the…

  6. University Community Survey.

    ERIC Educational Resources Information Center

    Francis, John Bruce; Lewis, Steven

    This report is of an omnibus survey of campus attitudes conducted by the Survey Research Center (SRC) of the State University of New York at Buffalo. Its primary purpose was to provide accurate information as a basis for effective decisions by institutional policy makers. A random sample of 326 students, 98 faculty, and 95 staff participated in…

  7. Attitude Surveys Document Sampler.

    ERIC Educational Resources Information Center

    Walker, Albert, Comp.

    This packet presents results of a series of attitude surveys representing a variety of purposes, methods and defined publics. They range from a simple questionnaire prepared and mailed to a small group of key individuals by a public relations staff to scientifically derived surveys purchased from Louis Harris and Associates and other research…

  8. Managing Online Survey Data

    ERIC Educational Resources Information Center

    Ritter, Lois A., Ed.; Sue, Valerie M., Ed.

    2007-01-01

    Managing data collected from online surveys may be a straightforward process involving no more than downloading a spreadsheet from a Web survey host and presenting descriptive statistics associated with each questionnaire item. On the other hand, if the evaluation objectives require more complex analysis and presentation of the data, it will be…

  9. Readership Surveys Build Confidence.

    ERIC Educational Resources Information Center

    Bohle, Bob

    1980-01-01

    Reports results of a survey of students' opinions of their school newspaper. Lists four changes that were based on the survey results: (1) added emphasis on meeting students' personal interest needs, (2) increase in short feature and humorous stories, (3) more persuasive editorial and opinion pieces, and (4) increase in advertising benefits for…

  10. Technology & Distance Learning Survey.

    ERIC Educational Resources Information Center

    Florida Human Resources Development, Inc., Gainesville.

    A survey was conducted to assess the current state of technology and distance learning awareness and usage in Florida's adult education and community-based programs. Data were gathered through a survey of 350 adult practitioners, literacy providers, community-based organizations and libraries throughout the state (125 responses [36 percent return…

  11. Surveying the Community.

    ERIC Educational Resources Information Center

    Brown, Marleen

    The booklet serves as a step-by-step guide to assist career education teachers and administrators in setting up a program of utilizing the resources in the community. It provides specific procedures, forms, and suggestions to help the school in surveying the community. Nine steps involved in surveying the community are discussed in detail: (1)…

  12. 2007 Maryland Adolescent Survey

    ERIC Educational Resources Information Center

    Maryland State Department of Education, 2008

    2008-01-01

    Periodically, Maryland's sixth, eighth, tenth, and twelfth graders are surveyed to determine the nature, extent, and trend of alcohol, tobacco, and other drug (ATOD) use among adolescents. The "2007 Maryland Adolescent Survey (MAS)" presents the latest findings regarding ATOD use by Maryland's adolescents and compares State and local findings with…

  13. Annual HR Salary Survey.

    ERIC Educational Resources Information Center

    Schaeffer, Patricia

    2000-01-01

    A trainers' salary survey collected data on 1,091 companies, 31,615 employees, and 97 human resource jobs. Results show pay for human resource professionals is continuing to rise. The survey contains information on base salaries, annual bonuses and incentives, and long-term eligibility incentives. (JOW)

  14. Physics Survey Overview

    SciTech Connect

    2002-12-30

    An overview of a series of assignments of the branches of physics carried out by the Board on Physics and Astronomy of the National Research Council. It identifies further theories in physics and makes recommendations on preventive priorities. The Board on Physics and Astronomy (BPA) has conducted a new decadal survey of physics entitled ''Physics in a New Era''. The survey includes assessments of the main branches of physics as well as certain selected emerging areas. The various elements of the survey were prepared by separately-appointed National Research Council (NRC) committees. The BPA formed the Physics Survey Overview Committee (PSOVC) to complete the survey by preparing an overview of the field of physics to summarize and synthesize the results of the various assessments and to address cross-cutting issues that concern physics as a whole.

  15. Building Technologies Residential Survey

    SciTech Connect

    Secrest, Thomas J.

    2005-11-07

    Introduction A telephone survey of 1,025 residential occupants was administered in late October for the Building Technologies Program (BT) to gather information on residential occupant attitudes, behaviors, knowledge, and perceptions. The next section, Survey Results, provides an overview of the responses, with major implications and caveats. Additional information is provided in three appendices as follows: - Appendix A -- Summary Response: Provides summary tabular data for the 13 questions that, with subparts, comprise a total of 25 questions. - Appendix B -- Benchmark Data: Provides a benchmark by six categories to the 2001 Residential Energy Consumption Survey administered by EIA. These were ownership, heating fuel, geographic location, race, household size and income. - Appendix C -- Background on Survey Method: Provides the reader with an understanding of the survey process and interpretation of the results.

  16. The Methanol Multibeam Survey

    NASA Astrophysics Data System (ADS)

    Green, James A.; Cohen, R. J.; Caswell, J. L.; Fuller, G. A.; Brooks, K.; Burton, M. G.; Chrysostomou, A.; Diamond, P. J.; Ellingsen, S. P.; Gray, M. D.; Hoare, M. G.; Masheder, M. R. W.; McClure-Griffiths, N.; Pestalozzi, M.; Phillips, C.; Quinn, L.; Thompson, M. A.; Voronkov, M.; Walsh, A.; Ward-Thompson, D.; Wong-McSweeney, D.; Yates, J. A.; Cox, J.

    2007-03-01

    A new 7-beam methanol multibeam receiver is being used to survey the Galaxy for newly forming massive stars, that are pinpointed by strong methanol maser emission at 6.668 GHz. The receiver, jointly constructed by Jodrell Bank Observatory (JBO) and the Australia Telescope National Facility (ATNF), was successfully commissioned at Parkes in January 2006. The Parkes-Jodrell survey of the Milky Way for methanol masers is two orders of magnitude faster than previous systematic surveys using 30-m class dishes, and is the first systematic survey of the entire Galactic plane. The first 53 days of observations with the Parkes telescope have yielded 518 methanol sources, of which 218 are new discoveries. We present the survey methodology as well as preliminary results and analysis.

  17. Web-Based Surveys: Not Your Basic Survey Anymore

    ERIC Educational Resources Information Center

    Bertot, John Carlo

    2009-01-01

    Web-based surveys are not new to the library environment. Although such surveys began as extensions of print surveys, the Web-based environment offers a number of approaches to conducting a survey that the print environment cannot duplicate easily. Since 1994, the author and others have conducted national surveys of public library Internet…

  18. Conducting an Energy Conservation Survey.

    ERIC Educational Resources Information Center

    Allen, Rodney F.; LaHart, David E.

    1999-01-01

    Describes a lesson where students conduct an attitude survey on energy conservation in order to learn about survey research and scales in handling survey data. Explains that the understanding of survey research and energy conservation is relevant to ones civic life. Provides the energy attitude survey the students used for data collection. (CMK)

  19. Indexing contamination surveys

    SciTech Connect

    Brown, R.L.

    1998-02-06

    The responsibility for safely managing the Tank Farms at Hanford belongs to Lockheed Martin Hanford Corporation which is part of the six company Project Hanford Management Team led by Fluor Daniel Hanford, Inc.. These Tank Farm Facilities contain numerous outdoor contamination areas which are surveyed at a periodicity consistent with the potential radiological conditions, occupancy, and risk of changes in radiological conditions. This document describes the survey documentation and data tracking method devised to track the results of contamination surveys this process is referred to as indexing. The indexing process takes a representative data set as an indicator for the contamination status of the facility. The data are further manipulated into a single value that can be tracked and trended using standard statistical methodology. To report meaningful data, the routine contamination surveys must be performed in a manner that allows the survey method and the data collection process to be recreated. Three key criteria are necessary to accomplish this goal: Accurate maps, consistent documentation, and consistent consolidation of data meeting these criteria provides data of sufficient quality to be tracked. Tracking of survey data is accomplished by converting the individual survey results into a weighted value, corrected for the actual number of survey points. This information can be compared over time using standard statistical analysis to identify trends. At the Tank Farms, the need to track and trend the facility`s radiological status presents unique challenges. Many of these Tank Farm facilities date back to the second world war. The Tank Farm Facilities are exposed to weather extremes, plant and animal intrusion, as well as all of the normal challenges associated with handling radiological waste streams. Routine radiological surveys did not provide a radiological status adequate for continuing comparisons.

  20. FLEXI Project Management Survey

    NASA Astrophysics Data System (ADS)

    Rohunen, Anna; Krzanik, Lech; Kuvaja, Pasi; Similä, Jouni; Rodriguez, Pilar; Hyysalo, Jarkko; Linna, Tommi

    FLEXI Project Management Survey (FLEXI PMS) has been established to gain detailed knowledge on how the software industry - in particular successful companies - manages agile software development. FLEXI PMS investigates the actual agile values, principles, practices and contexts. The survey is supported by a careful literature review and analysis of existing studies. Special attention is attached to large, multi-site, multi-company and distributed projects - the target area of FLEXI project. The survey is intended to provide solid data for further knowledge acquisition and project/company positioning with regard to feasible agile management practices.

  1. Public Surveys at ESO

    NASA Astrophysics Data System (ADS)

    Arnaboldi, M.; Delmotte, N.; Geier, S.; Hilker, M.; Hussain, G.; Mascetti, L.; Micol, A.; Petr-Gotzens, M.; Rejkuba, M.; Retzlaff, J.

    We provide an overview of the ESO public survey projects being carried out at the ESO survey telescopes, VISTA and VST, on the VLT instruments, UVES, FLAMES and VIMOS, and on the NTT, with SOFI and EFOSC, at the La Silla-Paranal Observatory. We outline the motivations behind these extensive projects, the policies and the facilities supporting these programmes. We illustrate how their data products are validated and published through the ESO Science Archive Facility, in order to make them accessible to the astronomical community. We conclude with an outlook on the future of public surveys at ESO.

  2. Survey of radar ADT

    NASA Astrophysics Data System (ADS)

    Trunk, G. V.

    1983-07-01

    The most recent advances in automatic detection and tracking are surveyed. The discussion deals with various noncoherent integrators that provide target enhancement, thresholding techniques for reducing false alarms and target suppression, and algorithms for estimating target position and resolving targets. Attention is also given to track-while-scan systems, and the entire tracking system is surveyed. This is followed by a discussion of the various components of the system, such as the tracking filter, maneuver-following logic, track initiation, and correlation logic. The survey concludes with a discussion of radar netting. It is emphasized that the automatic detector should be considered an integral part of the radar system.

  3. A Primer in Survey Research.

    ERIC Educational Resources Information Center

    Watson, Suzanne C.

    1998-01-01

    Compares types and methods of survey research, including mail, telephone, face-to-face, drop-off, and electronic surveys. Explains steps for conducting survey research and suggests how to improve response rate. (SK)

  4. Use of Public Opinion Surveys.

    ERIC Educational Resources Information Center

    Copeland, Susan

    2002-01-01

    Describes how to design and administer public-opinion surveys. Includes types of surveys, preparing survey questions, drawing and validating a sample, and processing the data. (Contains 16 references.) (PKP)

  5. Infrared Sky Surveys

    NASA Astrophysics Data System (ADS)

    Price, Stephan D.

    2009-02-01

    A retrospective is given on infrared sky surveys from Thomas Edison’s proposal in the late 1870s to IRAS, the first sensitive mid- to far-infrared all-sky survey, and the mid-1990s experiments that filled in the IRAS deficiencies. The emerging technology for space-based surveys is highlighted, as is the prominent role the US Defense Department, particularly the Air Force, played in developing and applying detector and cryogenic sensor advances to early mid-infrared probe-rocket and satellite-based surveys. This technology was transitioned to the infrared astronomical community in relatively short order and was essential to the success of IRAS, COBE and ISO. Mention is made of several of the little known early observational programs that were superseded by more successful efforts.

  6. Optical infrared sky survey

    NASA Technical Reports Server (NTRS)

    Craine, E. R.

    1978-01-01

    A description is presented of a photographic survey of the northern sky currently underway at Steward Observatory. The survey is being conducted at a principal bandpass of 8000-9000 A supplemented by a V bandpass. The survey is the first of its type conducted using a small (20-in. aperture) wide-field telescope, a very large-format (146 mm) image intensifier with a red-extended, multialkali photocathode. The output phosphor of the intensifier is photographed with IIaD emulsion on film. One of the goals of the survey is to catalog red stellar objects on the photographs and to examine in detail regions of the sky which are obscured by hydrogen emission on conventional photographs.

  7. Fuel cells: A survey

    NASA Technical Reports Server (NTRS)

    Crowe, B. J.

    1973-01-01

    A survey of fuel cell technology and applications is presented. The operating principles, performance capabilities, and limitations of fuel cells are discussed. Diagrams of fuel cell construction and operating characteristics are provided. Photographs of typical installations are included.

  8. The World Magnetic Survey

    NASA Technical Reports Server (NTRS)

    Heppner, J. P.

    1963-01-01

    The mathematical and graphical description of the earth's main field has been, and is, a "data limited" problem. The World Magnetic Survey (WMS) is an endeavor to minimize this limitation by rapidly and comprehensively blanketing the earth with magnetic field measurements. Satellite surveys, which will play a key role in the W MS, are the principal topic of this paper. Existing magnetic field descriptions, the expected results from new surveys, and the methods of obtaining these results with the POGO satellite are emphasized. It is anticipated on the basis of extrapolation from Vanguard 3 results and other considerations that a factor of 10 improvement will be obtained. This means that the average errors of 1 to 3 percent now present in field charts and spherical harmonic descriptions should be reduced to 0.1 to 0.3 percent as a result of the survey.

  9. National Nursing Home Survey

    Cancer.gov

    The National Nursing Home Survey provides includes characteristics such as size of nursing home facilities, ownership, Medicare/Medicaid certification, occupancy rate, number of days of care provided, and expenses.

  10. Web surveys' hidden hazards.

    PubMed

    Morrel-Samuels, Palmer

    2003-07-01

    The same question posed on the Web and in print can yield very different answers, dramatically distorting survey results and misleading management. But, as psychologist Palmer Morrel-Samuels demonstrates, the problems are readily fixed. PMID:12858707

  11. Benchmarking survey for recycling.

    SciTech Connect

    Marley, Margie Charlotte; Mizner, Jack Harry

    2005-06-01

    This report describes the methodology, analysis and conclusions of a comparison survey of recycling programs at ten Department of Energy sites including Sandia National Laboratories/New Mexico (SNL/NM). The goal of the survey was to compare SNL/NM's recycling performance with that of other federal facilities, and to identify activities and programs that could be implemented at SNL/NM to improve recycling performance.

  12. The DECam Legacy Survey

    NASA Astrophysics Data System (ADS)

    Blum, Robert D.; Burleigh, Kaylan; Dey, Arjun; Schlegel, David J.; Meisner, Aaron M.; Levi, Michael; Myers, Adam D.; Lang, Dustin; Moustakas, John; Patej, Anna; Valdes, Francisco; Kneib, Jean-Paul; Huanyuan, Shan; Nord, Brian; Olsen, Knut A.; Delubac, Timothée; Saha, Abi; James, David; Walker, Alistair R.; DECaLS Team

    2016-06-01

    The DECam Legacy Survey (DECaLS) is conducting a 3-band imaging survey of the Sloan Digital Sky Survey (SDSS) extragalactic footprint as part of the Legacy Survey, which is associated with the Dark Energy Spectroscopic Instrument (DESI) redshift survey. The Legacy Survey covers 14000 square degrees in the g, r, and z bands and is being executed on the Blanco 4-m, Mayall 4-m, and Bok 2.3-m telescopes. For DECaLS, the Dark Energy Camera (DECam) will image the footprint overlapping SDSS in the region -20 < Dec < +30 deg, to depths of g=24.7, r=23.9, z=23.0 and will eventually cover a total of 7500 square degrees. The survey began in 2014 and will run through Spring 2017. Images and catalogs were introduced in Public Data Release 2 (DR2), which occurred in January 2016. The algorithm "Tractor" applies multi-wavelength forced photometry to DECam and WISE data to produce galaxy (and star) magnitudes (as well as shape and other information) for the catalogs. In total, the optical data in DR2 cover a disjoint footprint in 2078, 2141 and 5322 square degrees in g, r, and z bands, respectively; 1807 square degrees has been observed in all three optical filters. There are approximately 260 million unique sources in DR2 spread over 97,554 0.25 x 0.25 square degree bricks.The Dark Energy Spectroscopic Instrument (DESI) will observe 30+ million galaxies and quasars in a 14,000 square degree extragalactic footprint. The targeting in that footprint will be provided by a combination of these DECam data, the MOSAIC camera on the Mayall 4-meter, and the 90Prime camera on the Bok telescope.

  13. Redshift Survey Strategies

    NASA Astrophysics Data System (ADS)

    Jones, A. W.; Bland-Hawthorn, J.; Kaiser, N.

    1994-12-01

    In the first half of 1995, the Anglo-Australian Observatory is due to commission a wide field (2.1(deg) ), 400-fiber, double spectrograph system (2dF) at the f/3.3 prime focus of the AAT 3.9m bi-national facility. The instrument should be able to measure ~ 4000 galaxy redshifts (assuming a magnitude limit of b_J ~\\ 20) in a single dark night and is therefore ideally suited to studies of large-scale structure. We have carried out simple 3D numerical simulations to judge the relative merits of sparse surveys and contiguous surveys. We generate a survey volume and fill it randomly with particles according to a selection function which mimics a magnitude-limited survey at b_J = 19.7. Each of the particles is perturbed by a gaussian random field according to the dimensionless power spectrum k(3) P(k) / 2pi (2) determined by Feldman, Kaiser & Peacock (1994) from the IRAS QDOT survey. We introduce some redshift-space distortion as described by Kaiser (1987), a `thermal' component measured from pairwise velocities (Davis & Peebles 1983), and `fingers of god' due to rich clusters at random density enhancements. Our particular concern is to understand how the window function W(2(k)) of the survey geometry compromises the accuracy of statistical measures [e.g., P(k), xi (r), xi (r_sigma ,r_pi )] commonly used in the study of large-scale structure. We also examine the reliability of various tools (e.g. genus) for describing the topological structure within a contiguous region of the survey.

  14. 2012 Mask Industry Survey

    NASA Astrophysics Data System (ADS)

    Malloy, Matt; Litt, Lloyd C.

    2012-11-01

    A survey supported by SEMATECH and administered by David Powell Consulting was sent to semiconductor industry leaders to gather information about the mask industry as an objective assessment of its overall condition. The survey was designed with the input of semiconductor company mask technologists and merchant mask suppliers. 2012 marks the 11th consecutive year for the mask industry survey. This year's survey and reporting structure are similar to those of the previous years with minor modifications based on feedback from past years and the need to collect additional data on key topics. Categories include general mask information, mask processing, data and write time, yield and yield loss, delivery times, and maintenance and returns. Within each category are multiple questions that result in a detailed profile of both the business and technical status of the mask industry. Results, initial observations, and key comparisons between the 2011 and 2012 survey responses are shown here, including multiple indications of a shift towards the manufacturing of higher end photomasks.

  15. ESR teleradiology survey: results.

    PubMed

    2016-08-01

    With recent developments of teleradiology technology and services, it has become necessary to better evaluate its extent and use among different countries in Europe. With this goal in mind, the ESR launched two specific surveys intended to gather the current state of adoption and implementation of teleradiology in clinical practice. A special focus on differentiating between insourcing teleradiology services among partners of the same organisation and outsourcing to external services was an essential part of the design of these surveys. The first survey was addressed to 44 national societies of different countries in Europe, while the second survey was intended for all practicing radiologist ESR members. While the results of these surveys reported here may provide a wealth of information to better understand the trends in adoption of teleradiology in Europe, they only represent a snapshot at a certain point in time. The rapid development of telecommunication tools as well as a fundamental change in practice and healthcare economics will certainly influence these observations in the upcoming years. These data, however, will provide objective and relevant parameters for supporting the efforts of experts and policy makers in promoting appropriate criteria and guidelines for adequate use of teleradiology in clinical practice. Main Messages • Understand concepts and challenges of teleradiology • Provide insight into current trends and solutions for teleradiology • Compare differences in teleradiolgy strategies between countries in Europe • Establish a reference on statistical data of usage of teleradiology in Europe. PMID:27188379

  16. Digital Optical Sky Surveys

    SciTech Connect

    Kron, R.G.

    1995-08-01

    Cameras containing arrays of charge-coupled devices---or which are otherwise capable of sustained high data rates---enable optical sky surveys that compete in efficiency with photographic surveys in terms of area of sky covered per unit observing time. There are gains in performance as well as efficiency: stellar photometry is more straightforward because of the higher dynamic range of CCDs, and the low noise of CCDs allows narrow-band surveys to be undertaken. The small dead-time between exposures allows surveys for rapid variability as well as near-simultaneous color measurements. The most important new prospect may be real-time analysis for identification of sources changing either in position or in brightness. These gains come only after substantial investment in analysis tools and data handling and storage systems. To illustrate some of this potential, this review will focus on a number of sky surveys with CCDs that are either under way or in advanced implementation stages. {copyright} {ital 1995} {ital Astronomical} {ital Society} {ital of} {ital the} {ital Pacific}.

  17. AERIAL RADIOLOGICAL SURVEYS

    SciTech Connect

    Proctor, A.E.

    1997-06-09

    Measuring terrestrial gamma radiation from airborne platforms has proved to be a useful method for characterizing radiation levels over large areas. Over 300 aerial radiological surveys have been carried out over the past 25 years including U.S. Department of Energy (DOE) sites, commercial nuclear power plants, Formerly Utilized Sites Remedial Action Program/Uranium Mine Tailing Remedial Action Program (FUSRAP/UMTRAP) sites, nuclear weapons test sites, contaminated industrial areas, and nuclear accident sites. This paper describes the aerial measurement technology currently in use by the Remote Sensing Laboratory (RSL) for routine environmental surveys and emergency response activities. Equipment, data-collection and -analysis methods, and examples of survey results are described.

  18. Balloon borne Infrared Surveys

    NASA Astrophysics Data System (ADS)

    Lubin, Philip M.

    2015-08-01

    We report on modeling of a balloon borne mission to survey the 1-5 micron region with sensitivity close to the zodiacal light limits in portions of this band. Such a survey is compelling for numerous science programs and is complimentary to the upcoming Euclid, WFIRST and other orbital missions. Balloons borne missions offer much lower cost access and rapid technological implementation but with much less exposure time and increased backgrounds. For some science missions the complimentary nature of these is extremely useful. .

  19. MSE velocity survey

    NASA Astrophysics Data System (ADS)

    Schimd, C.; Courtois, H.; Koda, J.

    2015-12-01

    A huge velocity survey based on the Maunakea Spectroscopic Explorer facility (MSE) is proposed, aiming at investigating the structure and dynamics of the cosmic web over 3π steradians up to ˜1 Gpc and at unprecedented spatial resolution, its relationship with the galaxy formation process, and the bias between galaxies and dark matter during the last three billions years. The cross-correlation of velocity and density fields will further allow the probe any deviation from General Relativity by measuring the the linear-growth rate of cosmic structures at precision competitive with high-redshift spectroscopic redshift surveys.

  20. Refraction corrections for surveying

    NASA Technical Reports Server (NTRS)

    Lear, W. M.

    1979-01-01

    Optical measurements of range and elevation angle are distorted by the earth's atmosphere. High precision refraction correction equations are presented which are ideally suited for surveying because their inputs are optically measured range and optically measured elevation angle. The outputs are true straight line range and true geometric elevation angle. The 'short distances' used in surveying allow the calculations of true range and true elevation angle to be quickly made using a programmable pocket calculator. Topics covered include the spherical form of Snell's Law; ray path equations; and integrating the equations. Short-, medium-, and long-range refraction corrections are presented in tables.

  1. Copyright Survey Results.

    ERIC Educational Resources Information Center

    Botterbusch, Hope R.

    1992-01-01

    Reports results of a survey of copyright concerns that was conducted by the Association for Educational Communications and Technology. Areas addressed include video and television; copyright legislation; printed materials; music; audiovisual materials; and computer software. A checklist of proper copyright procedures is included. (six references)…

  2. Survey of Solar Buildings.

    ERIC Educational Resources Information Center

    Gray, Robert; Baker, Steven

    This survey brings together information concerning the growing number of buildings utilizing solar energy and is designed to facilitate the comparison of specific characteristics of the buildings. The 66 U.S. entries are divided into five regions, arranged by state, and roughly by date within each state. Seven entries are from other countries. A…

  3. Health Occupations Survey.

    ERIC Educational Resources Information Center

    Willett, Lynn H.

    A survey was conducted to determine the need for health occupations personnel in the Moraine Valley Community College district, specifically to: (1) describe present employment for selected health occupations; (2) project health occupation employment to 1974; (3) identify the supply of applicants for the selected occupations; and (4) identify…

  4. Employment Discrimination: A Survey.

    ERIC Educational Resources Information Center

    Caplan, Gerald A.

    Chapter 4 in a book on school law provides a general overview of the various federal statutes directed toward discrimination in employment and considers some of the recent developments under these statutes. The first section is a survey of the employment discrimination laws and their interrelationships. The second section analyzes more closely…

  5. And the Survey Says...

    ERIC Educational Resources Information Center

    White, Susan C.

    2016-01-01

    Since 1987, the Statistical Research Center at the American Institute of Physics has regularly conducted a survey of high school physics teachers. This September we're at it again. This fall, we will look for physics teachers at each of the 4,000+ schools with 12th grade in our nationally representative sample of public and private schools. We…

  6. IBM Small Business Survey.

    ERIC Educational Resources Information Center

    International Business Machines Corp., Armonk, NY.

    A telephone survey conducted March 15-22, 1991, examined how small businesses are currently performing. Interviewees were 400 small business owners randomly selected from a Dun and Bradstreet list of companies with 50 or fewer employees. Major findings were as follows: (1) owners were survivors, highly confident in their own abilities, and…

  7. School Facilities Survey.

    ERIC Educational Resources Information Center

    Saunders, Harry B.

    This survey of facility needs includes an evaluation of staff organization and operating procedures for the Philadelphia Public School District. The educational policies adopted by the Philadelphia Board of Education relating to school facilities are discussed, and existing sites and buildings, population enrollment data, and financial data are…

  8. Surveys and Benchmarks

    ERIC Educational Resources Information Center

    Bers, Trudy

    2012-01-01

    Surveys and benchmarks continue to grow in importance for community colleges in response to several factors. One is the press for accountability, that is, for colleges to report the outcomes of their programs and services to demonstrate their quality and prudent use of resources, primarily to external constituents and governing boards at the state…

  9. Freshmen Survey. Fall 1985.

    ERIC Educational Resources Information Center

    Goodyear, Don

    In 1985, College of the Sequoias (COS) was asked by the Cooperative Institutional Research Program (conducted jointly by the American Council on Education and the University of California, Los Angeles) to participate in a survey of incoming freshmen for the fall 1985 semester. During the summer counseling session, 259 new COS freshmen were…

  10. AACC Nursing Survey.

    ERIC Educational Resources Information Center

    American Association of Community Colleges, Washington, DC.

    This document, presented in the form of PowerPoint print outs, indicates a total of 420 (nearly 60%) associate degree nursing (ADN) programs responded to a survey conducted by the American Association of Community Colleges' (AACC) Nursing and Allied Health Initiative (NAHI) for 2003. The sample is representative based on urbanicity and region.…

  11. An Astronomical Misconceptions Survey

    ERIC Educational Resources Information Center

    LoPresto, Michael C.; Murrell, Steven R.

    2011-01-01

    Misconceptions that students bring with them to the introductory science classroom plague every area of science and are especially prevalent in astronomy. One way to identify and possibly dispel some of these misconceptions is through the use of a misconceptions survey. The following is a report on the development, implementation, and some early…

  12. Marine Attitude Survey

    ERIC Educational Resources Information Center

    Hounshell, Paul B.; Hampton, Carolyn

    This 22-item Marine Attitude Survey was developed for use in elementary/middle schools to measure students' attitudes about various aspects of marine science. Students are asked if they agree, are not sure, or disagree with such items as: (1) the seashore is a fun place to visit; (2) if all sharks were killed, the world would be a better place;…

  13. Continuing Education Survey.

    ERIC Educational Resources Information Center

    Bird, K. A.; Fenwick, P. R.

    In 1978, a national survey was conducted in New Zealand to determine the extent of participation in continuing education and the level of unmet need for these activities. A questionnaire was developed dealing with respondent characteristics, spare time and interests, agency-directed learning activities (ADLAS), and unmet needs, and administered to…

  14. Conducting the Survey

    ERIC Educational Resources Information Center

    Ritter, Lois A., Ed.; Sue, Valerie M., Ed.

    2007-01-01

    Research regarding the optimal fielding of online surveys is in its infancy and just beginning to offer clear suggestions for effective recruiting of participants as well as techniques for maximizing the response rate. In this article, the authors discuss the process of recruiting participants by e-mailing invitations to a list of recipients…

  15. Questions for Surveys

    PubMed Central

    Schaeffer, Nora Cate; Dykema, Jennifer

    2011-01-01

    We begin with a look back at the field to identify themes of recent research that we expect to continue to occupy researchers in the future. As part of this overview, we characterize the themes and topics examined in research about measurement and survey questions published in Public Opinion Quarterly in the past decade. We then characterize the field more broadly by highlighting topics that we expect to continue or to grow in importance, including the relationship between survey questions and the total survey error perspective, cognitive versus interactional approaches, interviewing practices, mode and technology, visual aspects of question design, and culture. Considering avenues for future research, we advocate for a decision-oriented framework for thinking about survey questions and their characteristics. The approach we propose distinguishes among various aspects of question characteristics, including question topic, question type and response dimension, conceptualization and operationalization of the target object, question structure, question form, response categories, question implementation, and question wording. Thinking about question characteristics more systematically would allow study designs to take into account relationships among these characteristics and identify gaps in current knowledge. PMID:24970951

  16. Informatics: A Brief Survey.

    ERIC Educational Resources Information Center

    He, Shaoyi

    2003-01-01

    Provides a brief survey of informatics, defined as the application of information technology to various fields, with respect to its historical background, disciplinary identity, fundamental aspects, applications, and challenges. Highlights include biological, clinical, dental, environmental, geomatics, health, legal, management, medical, museum,…

  17. The GAMA Panchromatic Survey

    NASA Astrophysics Data System (ADS)

    Driver, Simon P.

    2013-07-01

    The Galaxy And Mass Assembly Survey (GAMA) has now been operating for almost 5 years gathering spectroscopic redshifts for five regions of sky spanning 300 sq degrees in total to a depth of r < 19.8 mag. The survey has amassed over 225,000 redshifts making it the third largest redshift campaign after the SDSS and BOSS surveys. The survey has two novel features that set it apart: (1) complete and uniform sampling to a fixed flux limit (r < 19.8 mag) regardless of galaxy clustering due to multiple-visits to each sky region, enabling the construction of high-fidelity catalogues of groups and pairs, (2) co-ordination with diverse imaging campaigns which together sample an extremely broad range along the electro-magnetic spectrum from the UV (GALEX) through optical (VST KIDs), near-IR (VISTA VIKING), mid-IR (WISE), far-IR (Herschel-Atlas), 1m (GMRT), and eventually 20cm continuum and rest-frame 21cm line measurements (ASKAP DINGO). Apart from the ASKAP campaign all multi-wavelength programmes are either complete or in the final stages of observations and the UV-far-IR data are expected to be fully merged by the end of 2013. This article provides a brief flavour of the coming panchromatic database which will eventually include measurements or upper-limits across 27 wavebands for 380,000 galaxies. GAMA DR2 is scheduled for the end of January 2013.

  18. Commercial Banking Industry Survey.

    ERIC Educational Resources Information Center

    Bright Horizons Children's Centers, Cambridge, MA.

    Work and family programs are becoming increasingly important in the commercial banking industry. The objective of this survey was to collect information and prepare a commercial banking industry profile on work and family programs. Fifty-nine top American commercial banks from the Fortune 500 list were invited to participate. Twenty-two…

  19. Bellarmine College Alumni Survey.

    ERIC Educational Resources Information Center

    Slesnick, Frank

    Alumni of Bellarmine College, Kentucky, who had obtained B.A. or B.S. degrees from 1974 to 1978 were surveyed in 1979. Areas of assessment were as follows: majors, desired occupation at time of graduation, attendance at graduate school, present employment status, jobs held by respondents, reasons why respondents chose their present jobs,…

  20. A Survey Transition Course

    ERIC Educational Resources Information Center

    Johnston, William; McAllister, Alex M.

    2012-01-01

    Successful outcomes for a "Transition Course in Mathematics" have resulted from two unique design features. The first is to run the course as a "survey course" in mathematics, introducing sophomore-level students to a broad set of mathematical fields. In this single mathematics course, undergraduates benefit from an introduction of proof…

  1. Management Values Survey Results.

    ERIC Educational Resources Information Center

    Duffy, Barbara; Payne, Ron

    1988-01-01

    Describes results of a survey conducted to compare values of members of the Association for Educational Communications and Technology (AECT) with managers in business and industry. Issues discussed include job satisfaction, opportunities for advancement, attitudes toward management, and salary; a summary of each value system is provided. (LRW)

  2. Refraction corrections for surveying

    NASA Technical Reports Server (NTRS)

    Lear, W. M.

    1980-01-01

    Optical measurements of range and elevation angles are distorted by refraction of Earth's atmosphere. Theoretical discussion of effect, along with equations for determining exact range and elevation corrections, is presented in report. Potentially useful in optical site surveying and related applications, analysis is easily programmed on pocket calculator. Input to equation is measured range and measured elevation; output is true range and true elevation.

  3. The Survey Questionnaire

    ERIC Educational Resources Information Center

    Ritter, Lois A. Ed.; Sue, Valerie M., Ed.

    2007-01-01

    Internet-based surveys are still relatively new, and researchers are just beginning to articulate best practices for questionnaire design. Online questionnaire design has generally been guided by the principles applying to other self-administered instruments, such as paper-based questionnaires. Web-based questionnaires, however, have the potential…

  4. And the Survey Says ...

    ERIC Educational Resources Information Center

    White, Susan C.

    2013-01-01

    Two-Year Colleges, Physics Majors, and Diversity. As noted last month, we're taking a look at physics in two-year colleges (TYCs). We expect to have the first reports from our 2012-13 Nationwide Survey of High School Physics Teachers in the spring of 2014. Last month we noted that the high school physics experience of undergraduate physics…

  5. Telecourse Student Survey, 1984.

    ERIC Educational Resources Information Center

    Brey, Ron; Grigsby, Charles

    In spring 1984, almost 8,000 students, who were enrolled in 42 different college-credit telecourses, were surveyed to determine the students' background, how they learned about telecourses, and how they intended to view programs. Data from the study were tabulated by state, course type, and selected individual courses and were cross-tabulated and…

  6. Training's Annual Salary Survey.

    ERIC Educational Resources Information Center

    Goldwasser, Donna

    2000-01-01

    A survey of trainers' (n=2,003) salaries compared salaries based on size of companies, geographic location, level of education, experience, gender, and age. At $60,794, the average training salary is only 2.8 percent higher than last year, compared to a 4.6 percent increase for the average salaried employee. (JOW)

  7. 12. Historic American Buildings Survey Topographic Survey of Cosmos Club, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Historic American Buildings Survey Topographic Survey of Cosmos Club, 1950, by Bernard Locroft, Civil Engineer (Showing Grounds as They Were at End of Sumner Welles Era) SITE PLAN - Townsend House, 2121 Massachusetts Avenue Northwest, Washington, District of Columbia, DC

  8. 2. Historic American Buildings Survey, Copied by Survey Photographer (e) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey, Copied by Survey Photographer (e) Ext-Old Photograph- Gen View North and East Elevations, (before 1868) - India Wharf Stores, 306-308 Atlantic Avenue, Boston, Suffolk County, MA

  9. 3. Historic American Buildings Survey, Copied by Survey Photographer. Taken ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Historic American Buildings Survey, Copied by Survey Photographer. Taken before 1868. (f) Ext- Old Photo-- General view from N.W. - India Wharf Stores, 306-308 Atlantic Avenue, Boston, Suffolk County, MA

  10. 1. Historic American Buildings Survey Copied by Survey, Photographer, Old ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Historic American Buildings Survey Copied by Survey, Photographer, Old Photo before 1880 (a) Ext-General view from Southwest. - Governor Thomas Prence House, King's Highway (U.S. Route 6), Eastham, Barnstable County, MA

  11. 17. Historic American Buildings Survey, PHOTOCOPY OF 1902 INSURANCE SURVEY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Historic American Buildings Survey, PHOTOCOPY OF 1902 INSURANCE SURVEY FROM THE COLLECTION OF THE FACTORY MUTUALS INSURANCE COMPANY, NORWOOD, MASS. - Clinton Mill, 93 Clinton Street, Woonsocket, Providence County, RI

  12. Survey report: Kenya.

    PubMed

    Van Der Tak, J

    1986-06-01

    In Kenya, women still average about 8 children each, but the average family size desired by ever-married women dropped by 1 child, from 7.2 to 6.2, between 1978-84. The percentage of currently married women using contraception more than doubled, from 7 to 17%. These are highlights of trends revealed by comparison of the recently released results of the Kenya Contraceptive Prevalence Survey of 1984 with the Kenya Fertility Survey of 1977-78. The latest trends in Kenya's fertility and family planning can be expected to be of worldwide interest in view of the country's record high population growth rate of 4.2% a year. Estimated at 21 million in 1986, the population of Kenya is projected by the UN to quadruple to 83 million by 2025 and could reach as high as 116 million by 2100, according to the World Bank. Among the reasons cited for the failure of Kenya's government family planning program, established in 1968, are bureaucratic snarls, shortages of supplies and trained personnel, and short business hours and long waits in clinics that are not always easily accessible in rural areas. These problems are now being dealt with, but there remains the obstacle of a persistent desire for large families among the population. Over 80% of the 6581 women aged 15-49 interviewed in the 1984 survey knew of at least 1 contraceptive method. The survey report terms the more than doubling of current contraceptive use between 1978-84 as a major success for the family planning program. Yet, the 1984 level is low. Also, the contraceptive mix shifted toward less effective methods. Among currently married women using contraception, the proportion using modern methods was down from 61% in 1978 to 52% in 1984, with oral contraceptive (OC) use dropping from 29 to 19% of the total and rhythm increasing from 16 to 25%. Fertility change was negligible. There was a slight increase in children ever born among women 45-49 from 7.9-8.2 per woman, along with a small decrease in the current total

  13. 2012 Global Management Education Graduate Survey. Survey Report

    ERIC Educational Resources Information Center

    Leach, Laura

    2012-01-01

    Each year for the past 13 years, the Graduate Management Admission Council (GMAC) has conducted a survey of graduate management education students in their final year of business school. The Global Management Education Graduate Survey is distributed to students at participating schools. The survey allows students to express their opinions about…

  14. Global Management Education Graduate Survey, 2011. Survey Report

    ERIC Educational Resources Information Center

    Schoenfeld, Gregg

    2011-01-01

    Each year for the past 12 years, the Graduate Management Admission Council[R] (GMAC[R]) has conducted a survey of graduate management education students in their final year of business school. This Global Management Education Graduate Survey is distributed to students at participating business schools. The survey allows students to express their…

  15. The MALT-45 Survey

    NASA Astrophysics Data System (ADS)

    Jordan, Christopher; Bains, Indra; Voronkov, Maxim; Lo, Nadia; Jones, Paul; Muller, Erik; Cunningham, Maria; Burton, Michael; Brooks, Kate; Green, James; Fuller, Gary; Barnes, Peter; Ellingsen, Simon; Urquhart, James; Morgan, Larry; Rowell, Gavin; Walsh, Andrew; Loenen, Edo; Baan, Willem; Hill, Tracey; Purcell, Cormac; Breen, Shari; Peretto, Nicolas; Jackson, James; Lowe, Vicki; Longmore, Steven

    2012-04-01

    As part of the MALT collaboration, we are proposing to undertake a survey of 5 square degrees of the Galactic plane with the ATCA at 7mm, called MALT-45. This survey is an untargeted search for CS (1-0), Class I methanol masers, SiO masers and thermal emission, and high frequency continuum emission. MALT-45 utilises our proven methods in on-the-fly mapping large areas of the sky, as well as pioneering autocorrelation results (using the ATCA both as an interferometer and a set of six individual single dishes). We will use the results to study high density star forming gas both on the near and far side of the Galaxy, to compare the occurrence of different maser species and to search for elusive hypercompact HII regions.

  16. The MALT-45 Survey

    NASA Astrophysics Data System (ADS)

    Jordan, Christopher; Bains, Indra; Voronkov, Maxim; Lo, Nadia; Jones, Paul; Muller, Erik; Cunningham, Maria; Burton, Michael; Brooks, Kate; Green, James; Fuller, Gary; Barnes, Peter; Ellingsen, Simon; Urquhart, James; Morgan, Larry; Rowell, Gavin; Walsh, Andrew; Loenen, Edo; Baan, Willem; Hill, Tracey; Purcell, Cormac; Breen, Shari; Peretto, Nicolas; Jackson, James; Lowe, Vicki; Longmore, Steven

    2013-04-01

    As part of the MALT collaboration, we are proposing to undertake a survey of 5 square degrees of the Galactic plane with the ATCA at 7mm, called MALT-45. This survey is an untargeted search for CS (1-0), Class I methanol masers, SiO masers and thermal emission, and high frequency continuum emission. MALT-45 utilises our proven methods in on-the-fly mapping large areas of the sky, as well as pioneering autocorrelation results (using the ATCA both as an interferometer and a set of six individual single dishes). We will use the results to study high density star forming gas both on the near and far side of the Galaxy, to compare the occurrence of different maser species and to search for elusive hypercompact HII regions.

  17. The MALT-45 Survey

    NASA Astrophysics Data System (ADS)

    Jordan, Christopher; Bains, Indra; Voronkov, Maxim; Lo, Nadia; Jones, Paul; Muller, Erik; Cunningham, Maria; Burton, Michael; Brooks, Kate; Green, James; Fuller, Gary; Barnes, Peter; Ellingsen, Simon; Urquhart, James; Morgan, Larry; Rowell, Gavin; Walsh, Andrew; Loenen, Edo; Baan, Willem; Hill, Tracey; Purcell, Cormac; Breen, Shari; Peretto, Nicolas; Jackson, James; Lowe, Vicki; Longmore, Steven

    2012-10-01

    As part of the MALT collaboration, we are proposing to undertake a survey of 5 square degrees of the Galactic plane with the ATCA at 7mm, called MALT-45. This survey is an untargeted search for CS (1-0), Class I methanol masers, SiO masers and thermal emission, and high frequency continuum emission. MALT-45 utilises our proven methods in on-the-fly mapping large areas of the sky, as well as pioneering autocorrelation results (using the ATCA both as an interferometer and a set of six individual single dishes). We will use the results to study high density star forming gas both on the near and far side of the Galaxy, to compare the occurrence of different maser species and to search for elusive hypercompact HII regions.

  18. The VMC Survey

    NASA Astrophysics Data System (ADS)

    Cioni, M.-R. L.

    The VISTA survey of the Magellanic Clouds system (VMC) is a public survey project of ESO. It is collecting near-infrared data across large areas of the Large and Small Magellanic Clouds, the Bridge and a few fields in the Stream. The combination of great sensitivity to stars below the old main sequence turn off, and the multiplicity at K s band (at least 12 epochs) make VMC highly suitable for the determination of the spatially resolved star formation history and three-dimensional geometry, using variable stars such as Cepheids and RR Lyrae stars. The VMC observations, to be completed in 2018, have a high legacy value and many science results have already been published while others are in preparation.

  19. ARM User Survey Report

    SciTech Connect

    Roeder, LR

    2010-06-22

    The objective of this survey was to obtain user feedback to, among other things, determine how to organize the exponentially growing data within the Atmospheric Radiation Measurement (ARM) Climate Research Facility, and identify users’ preferred data analysis system. The survey findings appear to have met this objective, having received approximately 300 responses that give insight into the type of work users perform, usage of the data, percentage of data analysis users might perform on an ARM-hosted computing resource, downloading volume level where users begin having reservations, opinion about usage if given more powerful computing resources (including ability to manipulate data), types of tools that would be most beneficial to them, preferred programming language and data analysis system, level of importance for certain types of capabilities, and finally, level of interest in participating in a code-sharing community.

  20. Survey of digital filtering

    NASA Technical Reports Server (NTRS)

    Nagle, H. T., Jr.

    1972-01-01

    A three part survey is made of the state-of-the-art in digital filtering. Part one presents background material including sampled data transformations and the discrete Fourier transform. Part two, digital filter theory, gives an in-depth coverage of filter categories, transfer function synthesis, quantization and other nonlinear errors, filter structures and computer aided design. Part three presents hardware mechanization techniques. Implementations by general purpose, mini-, and special-purpose computers are presented.

  1. Mescaline: a survey.

    PubMed

    Schwartz, R H

    1988-04-01

    The hallucinogen mescaline is found in the peyote and San Pedro cacti, which are prevalent in Mexico and the southwestern United States. In a survey of middle-class, predominantly white adolescents in a drug treatment facility, 18 percent of the respondents indicated that they had taken mescaline. Much of the purported mescaline was probably another hallucinogen, usually LSD. The effects of equipotent doses of mescaline and LSD are almost indistinguishable.

  2. Survey report: Pakistan.

    PubMed

    Zheng, J

    1991-10-01

    Pakistan suffers an unsuccessful population policy, with a resultant annual population growth of greater than 3%. Cultural and religious objections to family planning (FP) are recognized as the major obstacles to reducing fertility. Accordingly, a 1990-91 demographic and health survey was conducted to elicit information or fertility, family planning, marriage patterns, breastfeeding, and child health for planners and policymakers. The survey was jointly funded by the U.S. Agency for International Development and the government of Pakistan, and interviewed 6,494 ever-married women aged 15-49. The average total fertility rate for the 6-year period prior to the survey was 5.5 lifetime births/woman, less than the figure of greater than 6 found in previous surveys. Increasing age at 1st marriage and a slightly higher level of contraceptive use may be causal factors for the observed decline. Decreased fertility notwithstanding, contraceptive prevalence is low compared to other developing countries in Asia. 1 out of 5 Pakistani women report ever having used contraceptives, and no single method has ever been used by more than 7% of married women. 7% use condoms, 5% the pill, 3% female sterilization, and 3 the IUD and injections, with male sterilization virtually nonexistent, and only limited knowledge of barrier methods. Contraceptive prevalence, including traditional methods, among married women was 12%, with higher coverage in cities, especially among educated women. 37% desire no additional children, and 18% wish to delay child birth for 2 years. Intervention strategy may include working to improve the status of women, fostering greater educational opportunities for women, changing traditional attitudes toward large families and son preference, providing sufficient FP services, and getting commitments for support and action from government and community leaders. PMID:12284304

  3. Sloan digital sky survey

    SciTech Connect

    Kent, S.M.; Stoughton, C.; Newberg, H.; Loveday, J.; Petravick, D.; Gurbani, V.; Berman, E.; Sergey, G.; Lupton, R.

    1994-04-01

    The Sloan Digital Sky Survey will produce a detailed digital photometric map of half the northern sky to about 23 magnitude using a special purpose wide field 2.5 meter telescope. From this map we will select {approximately} 10{sup 6} galaxies and 10{sup 5} quasars, and obtain high resolution spectra using the same telescope. The imaging catalog will contain 10{sup 8} galaxies, a similar number of stars, and 10{sup 6} quasar candidates.

  4. Spectroscopic survey of LAMOST

    NASA Astrophysics Data System (ADS)

    Zhao, Yongheng

    2014-07-01

    LAMOST is a special reflecting Schmidt telescope. LAMOST breaks through the bottleneck of the large scale spectroscopic survey observation with both large aperture (effective aperture of 3.6 - 4.9m) and wide field of view (5 degrees). It is an innovative active reflecting Schmidt configuration achieved by changing mirror surface continuously to achieve a series different reflecting Schmidt system in different moments. By using the parallel controllable fiber positioning technique, the focal surface of 1.75 meters in diameter accommodates 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST is the telescope of the highest spectrum acquiring rate. As a national large scientific project, LAMOST project was proposed formally in 1996. The construction was started in 2001 and completed in 2008. After commission period, LAMOST pilot survey was started in October 2011 and spectroscopic survey began in September 2012. From October 2011 to June 2013, LAMOST has obtained more than 2 million spectra of celestial objects. There are 1.7 million spectra of stars, in which the stellar parameters (effective temperature, surface gravity, metalicitiy and radial velocity) of more than 1 million stars was obtained. In the first period of spectroscopic survey of LAMOST, 5 million of stellar spectra will be obtained and will make substantial contribution to the study of the stellar astrophysics and the structure of the Galaxy, such as the spheroid substructure of the Galaxy, the galactic gravitational potential and the distribution of the dark matter in the Galaxy, the extremely metal poor stars and hypervelocity stars, the 3D extinction in the Galaxy, the structure of thin and thick disks of the Galaxy, and so on.

  5. BLAST: THE REDSHIFT SURVEY

    SciTech Connect

    Eales, Stephen; Dye, Simon; Mauskopf, Philip; Moncelsi, Lorenzo; Pascale, Enzo; Raymond, Gwenifer; Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen; Scott, Douglas; Devlin, Mark J.; Rex, Marie; Semisch, Christopher; Truch, Matthew D. P.; Hughes, David H.; Netterfield, Calvin B.; Viero, Marco P.; Patanchon, Guillaume; Siana, Brian

    2009-12-20

    The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) has recently surveyed approx =8.7 deg{sup 2} centered on Great Observatories Origins Deep Survey-South at 250, 350, and 500 mum. In Dye et al., we presented the catalog of sources detected at 5sigma in at least one band in this field and the probable counterparts to these sources in other wavebands. In this paper, we present the results of a redshift survey in which we succeeded in measuring redshifts for 82 of these counterparts. The spectra show that the BLAST counterparts are mostly star-forming galaxies but not extreme ones when compared to those found in the Sloan Digital Sky Survey. Roughly one quarter of the BLAST counterparts contain an active nucleus. We have used the spectroscopic redshifts to carry out a test of the ability of photometric redshift methods to estimate the redshifts of dusty galaxies, showing that the standard methods work well even when a galaxy contains a large amount of dust. We have also investigated the cases where there are two possible counterparts to the BLAST source, finding that in at least half of these there is evidence that the two galaxies are physically associated, either because they are interacting or because they are in the same large-scale structure. Finally, we have made the first direct measurements of the luminosity function in the three BLAST bands. We find strong evolution out to z = 1, in the sense that there is a large increase in the space density of the most luminous galaxies. We have also investigated the evolution of the dust-mass function, finding similar strong evolution in the space density of the galaxies with the largest dust masses, showing that the luminosity evolution seen in many wavebands is associated with an increase in the reservoir of interstellar matter in galaxies.

  6. Quality Culture Survey Report.

    PubMed

    Patel, Pritesh; Baker, Denyse; Burdick, Rick; Chen, Cylia; Hill, Jonathon; Holland, Morgan; Sawant, Anil

    2015-01-01

    The Parenteral Drug Association conducted an anonymous global survey of quality culture in the pharmaceutical industry to determine whether there is a relationship between certain quality behaviors and certain quality attributes, and whether these quality attributes could be used as surrogates (or proxy variables) to assess quality culture. Other studies have shown that an unhealthy quality culture is a root cause of many quality or compliance issues seen by sites and organizations. Statistical analysis of survey data suggests that certain attributes are driving good behaviors, and the demographic data suggests that this relationship holds irrespective of the geographic location of the site. Executive survey respondents had a more optimistic view of the current state of quality culture than survey respondents at large, with cross-functional vision showing the biggest gap (P-value = 0.07, F-Test). The top five quality attributes that can serve as surrogates for quality culture were (1) Management communication that quality is everyone's responsibility, (2) Site has formal quality improvement objectives and targets, (3) Clear performance criteria for feedback and coaching, (4) Quality topics included in at least half of all-hands meetings, and (5) Collecting error prevention metrics. These identified mature quality attributes are related to management responsibility, and continual improvement of the pharmaceutical quality system sections of ICH Q10, and therefore may be amenable to be incorporated in audit programs or in regulatory inspections. Additional research and discussion is required to build a coherent approach, which the pharmaceutical industry and regulators can adopt. PMID:26429110

  7. Robotic and Survey Telescopes

    NASA Astrophysics Data System (ADS)

    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.

  8. The Einstein Slew Survey

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Plummer, David; Schachter, Jonathan; Fabbiano, G.

    1992-01-01

    A catalog of 819 sources detected in the Einstein IPC Slew Survey of the X-ray sky is presented; 313 of the sources were not previously known as X-ray sources. Typical count rates are 0.1 IPC count/s, roughly equivalent to a flux of 3 x 10 exp -12 ergs/sq cm s. The sources have positional uncertainties of 1.2 arcmin (90 percent confidence) radius, based on a subset of 452 sources identified with previously known pointlike X-ray sources (i.e., extent less than 3 arcmin). Identifications based on a number of existing catalogs of X-ray and optical objects are proposed for 637 of the sources, 78 percent of the survey (within a 3-arcmin error radius) including 133 identifications of new X-ray sources. A public identification data base for the Slew Survey sources will be maintained at CfA, and contributions to this data base are invited.

  9. 2013 mask industry survey

    NASA Astrophysics Data System (ADS)

    Malloy, Matt

    2013-09-01

    A comprehensive survey was sent to merchant and captive mask shops to gather information about the mask industry as an objective assessment of its overall condition. 2013 marks the 12th consecutive year for this process. Historical topics including general mask profile, mask processing, data and write time, yield and yield loss, delivery times, maintenance, and returns were included and new topics were added. Within each category are multiple questions that result in a detailed profile of both the business and technical status of the mask industry. While each year's survey includes minor updates based on feedback from past years and the need to collect additional data on key topics, the bulk of the survey and reporting structure have remained relatively constant. A series of improvements is being phased in beginning in 2013 to add value to a wider audience, while at the same time retaining the historical content required for trend analyses of the traditional metrics. Additions in 2013 include topics such as top challenges, future concerns, and additional details in key aspects of mask masking, such as the number of masks per mask set per ground rule, minimum mask resolution shipped, and yield by ground rule. These expansions beyond the historical topics are aimed at identifying common issues, gaps, and needs. They will also provide a better understanding of real-life mask requirements and capabilities for comparison to the International Technology Roadmap for Semiconductors (ITRS).

  10. Spectroscopic survey of LAMOST

    NASA Astrophysics Data System (ADS)

    Zhao, Yongheng

    2015-08-01

    LAMOST is a special reflecting Schmidt telescope. LAMOST breaks through the bottleneck of the large scale spectroscopic survey observation with both large aperture (effective aperture of 3.6 - 4.9m) and wide field of view (5 degrees). It is an innovative active reflecting Schmidt configuration achieved by changing mirror surface continuously to achieve a series different reflecting Schmidt system in different moments. By using the parallel controllable fiber positioning technique, the focal surface of 1.75 meters in diameter accommodates 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST is the telescope of the highest spectrum acquiring rate.In the spectroscopic survey of LAMOST from October 2011 to June 2014, LAMOST has obtained more than 4.13 million spectra of celestial objects. There are 3.27 million spectra of stars, in which the stellar parameters of 2.16 million stars were obtained.In the five-year regular survey upto 2017, LAMOST will obtaine 5 million stellar spectra, which would make substantial contribution to the study of the stellar astrophysics and the structure of the Galaxy, such as the spheroid substructure of the Galaxy, the galactic gravitational potential and the distribution of the dark matter in the Galaxy, the extremely metal poor stars and hypervelocity stars, the 3D extinction in the Galaxy, the structure of thin and thick disks of the Galaxy, and so on.

  11. Shapley Supercluster Survey

    NASA Astrophysics Data System (ADS)

    Merluzzi, P.; Busarello, G.; Haines, C. P.; Mercurio, A.; Grado, A.; Limatola, L.; Pimbblett, K. J.

    Our multi-wavelength survey of the Shapley supercluster (z ˜ 0.05) covers a contiguous area of 260 h 70 -2 Mpc2 including the supercluster core. The project's main aim is to quantify the influence of cluster-scale mass assembly on galaxy evolution in one of the most massive structures in the local Universe. The Shapley supercluster survey (ShaSS) includes nine Abell clusters (A 3552, A 3554, A 3556, A 3558, A 3559, A 3560, A 3562, AS 0724, AS 0726) and two poor clusters (SC 1327-312, SC 1329-313) showing evidence of cluster-cluster interactions. Optical (ugri) and near-infrared (K) imaging acquired with VST and VISTA allow us to study the galaxy population down to m^{star} + 6 at the supercluster redshift. A dedicated spectroscopic survey with AAOmega on the Anglo-Australian Telescope provides a magnitude-limited sample of supercluster members with 80 % completeness at ˜ m^{star} + 3.

  12. Onychomycosis. A Mexican survey.

    PubMed

    Arenas, Roberto; Bonifaz, Alexandro; Padilla, Ma Carmen; Arce, Martín; Atoche, Carlos; Barba, José; Campos, Pablo; Fernández, Ramón; Mayorga, Jorge; Nazar, Dulce; Ocampo, Jorge

    2010-01-01

    Onychomycosis is a nail infection caused by dermatophytes, Candida and molds. We aimed to obtain an estimated frequency of onychomycosis in out-patients in private practice through a survey in ten representative cities of Mexico. 12,637 ambulatory patients voluntarily agreed to participate in this National Survey, answering 17 questions on onychomycosis, regardless if they had or did not have any clinical suspicion of onychomycosis. 53% of them were seen for the first time and their main complaint was not onychomycosis. The study was performed in the private offices of 300 physicians in different cities. 48% were clinically diagnosed with onychomycosis. Toenails were affected in 88%, fingernails in 5% and both in 7%. Onychomycosis was diagnosed more frequently in the nails of the first toes and of the thumbs. The main complaint was nail thickening and aesthetic changes. Other associated diseases were diabetes (22%) and arterial hypertension (21%). This survey showed the high frequency of onychomycosis. An intentional search with mycological confirmation is needed in out-patients attending general practice with other complaints, to detect undiagnosed cases.

  13. Sport Management Survey. Employment Perspectives.

    ERIC Educational Resources Information Center

    Quain, Richard J.; Parks, Janet B.

    1986-01-01

    A survey of sport management positions was designed to determine projected vacancy rates in six sport management career areas. Respondents to the survey were also questioned regarding their awareness of college professional preparation programs. Results are presented. (MT)

  14. EuroGeoSurveys

    NASA Astrophysics Data System (ADS)

    Demicheli, L.; Ludden, J. N.; Robida, F.

    2012-04-01

    In order to create safe, healthy and wealthy places to live in, it is vital that we understand our planet. At national level the collection of information on the state of the solid Earth and its processes is normally mandated to Geological Surveys. In fact, a Geological Survey is the national institution responsible for the geological inventory, monitoring, knowledge and research for the security, health and prosperity of the society. And EuroGeoSurveys (EGS) is the organisation representing the Geological Surveys from 33 countries around Europe. With one member for each country of the European Union and beyond, including the Russian Federation and Ukraine, the EGS network covers the whole continent. EGS'principal purpose is to provide geoscientific knowledge that underpins European policies and regulations for the benefit of society. Naturally, in our day-to-day activities, we contribute to the merging of economic, environmental and social agendas. Engaging a joint workforce of several thousands of geoscientists, also involving regional geological surveys in Germany, Italy and Spain, we strive to be the first body to be contacted when there is an international need for European geodata, or'geo-help'. For this reason we work on a daily basis with the EU institutions, and are considered the natural source of information on Earth science issues and relevant downstream applications in Europe. Our General Secretariat is based in the European Quarter of Brussels close to the European Commission, the EU Council, the European Parliament, and the political seat of NATO. Our operational strategy is based on the cooperation between national institutions, which enables to synergistically integrate both information and activities of our member organisations. This has allowed us to make significant progress over the years, permitting geology to become a topic deserving great attention on the European agenda. In order to enable a quick but high quality response to requests for

  15. Preventing pitfalls in patient surveys.

    PubMed

    Steiber, S R

    1989-05-01

    Properly conceived, customer satisfaction surveys can yield the quantitative data needed to gauge patient satisfaction. But, as the author notes, these surveys can be "a veritable mine field of surprises for the uninitiated." This article, the last in a three-part series on measuring patient satisfaction, describes potential pitfalls and discusses the merits of in-person, mail and telephone surveys. PMID:10293191

  16. Interactive Features of Web Surveys

    ERIC Educational Resources Information Center

    Conrad, Frederick G.

    2007-01-01

    Educational researchers and policy makers have come to rely on data from sample surveys. However, survey research on educational issues poses some special challenges. In many respects, the survey methodology issues in educational research are the same as those throughout the social and behavioral sciences. These issues concern obtaining the best…

  17. Preventing pitfalls in patient surveys.

    PubMed

    Steiber, S R

    1989-05-01

    Properly conceived, customer satisfaction surveys can yield the quantitative data needed to gauge patient satisfaction. But, as the author notes, these surveys can be "a veritable mine field of surprises for the uninitiated." This article, the last in a three-part series on measuring patient satisfaction, describes potential pitfalls and discusses the merits of in-person, mail and telephone surveys.

  18. Youth Needs Survey: Fall 1983.

    ERIC Educational Resources Information Center

    Austin Independent School District, TX. Office of Research and Evaluation.

    In October 1983, 1,275 Austin Independent School District (AISD) secondary students completed a survey of their needs for social services. The survey was approved by the Board of Trustees in response to a request by the Social Policy Advisory Committee (SPAC). The purpose of the survey was to aid the SPAC in planning social services to meet the…

  19. Nursing Alumni Surveys: 2002 Graduates.

    ERIC Educational Resources Information Center

    College of the Canyons, Santa Clarita, CA.

    This document reports on outcomes of the College of the Canyons, California, 2002 survey of nursing alumni. Surveys of RN, LVN, and LVN-RN graduates and their employers aimed to assess graduates' satisfaction with the preparation and training they received. Surveys also collected information intended to assess the current position in which the…

  20. Current Issues Survey Report, 2007

    ERIC Educational Resources Information Center

    Camp, John S.; DeBlois, Peter B.

    2007-01-01

    The Eighth Annual EDUCAUSE Current Issues Survey asked campus information technology leaders to rate the most critical IT challenges facing them, their campuses, and/or their systems. Four findings associated with all respondents to this year's survey merit special mention. First, for the 2007 survey, the CIC decided to split a key issue choice…

  1. All sky Northern Hemisphere 10(15) EV gamma-ray survey

    NASA Technical Reports Server (NTRS)

    Baltrusaitis, R. M.; Cassiday, G. L.; Cooper, R.; Elbert, J. W.; Gerhardy, P. R.; Loh, E. C.; Mizumoto, Y.; Sokolsky, P.; Sommers, P.; Steck, D.

    1985-01-01

    Flux limits in the range 10 to the minus 13th power-10 to the minus 12 power/sq cm/s have been obtained by observing Cerenkov flashes from small air showers. During 1983, a 3.5 sigma excess of showers was observed during the phase interval 0.2 to 0.3 of the 4.8h period of Cygnus X-3, but no excess was found in 1984 observations.

  2. Sampling Procedures and Survey Methodologies for the 1996 Survey with Comparisons to Earlier National Roadside Surveys.

    ERIC Educational Resources Information Center

    Lestina, Diane C.; Greene, Michael; Voas, Robert B.; Wells, Joann

    1999-01-01

    Describes the multistage sampling system used in the 1996 national roadside survey of driver blood alcohol and compares it to the sampling methods used in prior surveys in 1973 and 1986. Although many more drivers were sampled in the most recent survey, the procedures are similar enough to allow comparison of results. (SLD)

  3. Unconscious knowledge: A survey

    PubMed Central

    Augusto, Luís M.

    2011-01-01

    The concept of unconscious knowledge is fundamental for an understanding of human thought processes and mentation in general; however, the psychological community at large is not familiar with it. This paper offers a survey of the main psychological research currently being carried out into cognitive processes, and examines pathways that can be integrated into a discipline of unconscious knowledge. It shows that the field has already a defined history and discusses some of the features that all kinds of unconscious knowledge seem to share at a deeper level. With the aim of promoting further research, we discuss the main challenges which the postulation of unconscious cognition faces within the psychological community. PMID:21814538

  4. Risk analysis methodology survey

    NASA Technical Reports Server (NTRS)

    Batson, Robert G.

    1987-01-01

    NASA regulations require that formal risk analysis be performed on a program at each of several milestones as it moves toward full-scale development. Program risk analysis is discussed as a systems analysis approach, an iterative process (identification, assessment, management), and a collection of techniques. These techniques, which range from simple to complex network-based simulation were surveyed. A Program Risk Analysis Handbook was prepared in order to provide both analyst and manager with a guide for selection of the most appropriate technique.

  5. 2009 Observer Survey Report

    USGS Publications Warehouse

    Crimmins, Theresa M.; Rosemartin, Alyssa H.; Lincicome, Alexis; Weltzin, Jake F.

    2010-01-01

    Survey participants’ suggestions for improving the program fell into several categories, including the need for a more expansive list of plants from which to pick, the ability to monitor animals, and more information on the plants, including photographs of the various phenophases to aid in identification. Participants also requested increased contact from the USA‐NPN, in the form of weekly or monthly emails or newsletters and reminders to collect and submit observations. Many of these suggestions are either already being addressed in changes being made to the monitoring system and online entry system or are planned for the future.

  6. ALHAMBRA survey: morphological classification

    NASA Astrophysics Data System (ADS)

    Pović, M.; Huertas-Company, M.; Márquez, I.; Masegosa, J.; Aguerri, J. A. López; Husillos, C.; Molino, A.; Cristóbal-Hornillos, D.

    2015-03-01

    The Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey is a photometric survey designed to study systematically cosmic evolution and cosmic variance (Moles et al. 2008). It employs 20 continuous medium-band filters (3500 - 9700 Å), plus JHK near-infrared (NIR) bands, which enable measurements of photometric redshifts with good accuracy. ALHAMBRA covers > 4 deg2 in eight discontinuous regions (~ 0.5 deg2 per region), of theseseven fields overlap with other extragalactic, multiwavelength surveys (DEEP2, SDSS, COSMOS, HDF-N, Groth, ELAIS-N1). We detect > 600.000 sources, reaching the depth of R(AB) ~ 25.0, and photometric accuracy of 2-4% (Husillos et al., in prep.). Photometric redshifts are measured using the Bayesian Photometric Redshift (BPZ) code (Benítez et al. 2000), reaching one of the best accuracies up to date of δz/z <= 1.2% (Molino et al., in prep.). To deal with the morphological classification of galaxies in the ALHAMBRA survey (Pović et al., in prep.), we used the galaxy Support Vector Machine code (galSVM; Huertas-Company 2008, 2009), one of the new non-parametric methods for morphological classification, specially useful when dealing with low resolution and high-redshift data. To test the accuracy of our morphological classification we used a sample of 3000 local, visually classified galaxies (Nair & Abraham 2010), moving them to conditions typical of our ALHAMBRA data (taking into account the background, redshift and magnitude distributions, etc.), and measuring their morphology using galSVM. Finally, we measured the morphology of ALHAMBRA galaxies, obtaining for each source seven morphological parameters (two concentration indexes, asymmetry, Gini, M20 moment of light, smoothness, and elongation), probability if the source belongs to early- or late-type, and its error. Comparing ALHAMBRA morph COSMOS/ACS morphology (obtained with the same method) we expect to have qualitative separation in two main morphological

  7. Sloan Digital Sky Survey

    SciTech Connect

    Kent, S.M.

    1993-11-01

    The Solan Digital Sky Survey is a project which will produce a detailed digital phometric map of half the northern sky to about 23 magnitude using a special purpose wide field telescope of 2.5 meter aperture. This map will be used to select about a million galaxies and 100,000 quasars, for which high resolution spectra will be obtained using the same telescope. A catalog will be produced of all the detected objects, about 100 million galaxies and a similar number of stars, and a million quasar candidates.

  8. Southern Sky Redshift Survey

    SciTech Connect

    Da Costa, L.N.; Pellegrini, P.S.; Sargent, W.L.W.; Tonry, J.; Davis, M.

    1988-04-01

    The general characteristics of the space distribution of galaxies in the SSRS sample, covering the southern Galactic cap, are examined, and maps of the space distribution are presented. The sample consists of 2028 galaxies in an area of 1.75 sr with declination south of -17.5 deg and galactic latitude below -30 deg. The survey provides useful information on large-scale structure to a depth of 120/h Mpc. The galaxy distribution exhibits prominent filaments, sheets, and voids. Some large-scale structures are highly subclustered; others are much more diffuse. 21 references.

  9. 2001 salary survey.

    PubMed

    Bolster, C J; Snow, J

    2001-09-01

    Boards are coming to respect how challenging it is to run a hospital, and increasingly view it as too big a job for one person. In our annual compensation survey report, Hay Group analysts assert that lower-level executives, senior managers and even middle managers have seen their stock rise in health care organizations, and that's reflected in the pay structure. Even so, CEOs aren't exactly struggling--but their total compensation still lags behind that of their counterparts in other industries. PMID:11579765

  10. Detergent toxicity survey.

    PubMed

    Seabaugh, V M; Bayard, S P; Osterberg, R E; Porter, W K; McCaulley, D F; Hoheisel, C A; Hehir, R M; Bierbower, G W

    1977-04-01

    A survey of over 249 detergent products involving biological testing, chemical analyses, and product label reviews has been conducted from 1971-1976 for determining compliance with the Federal Hazardous Substances Act. Test results for 145 detergent products having both chemical and biological data were examined. All of the tested detergents were rabbit eye irritants. Forty-seven per cent were also either rabbit primary skin irritants or corrosives. Eighty-one per cent were either rabbit esophageal test irritants or corrosives, and 80 per cent had rat oral toxicities 5g/kg or less.

  11. AzTEC COSMOS Survey

    NASA Astrophysics Data System (ADS)

    Yun, Min Su; Ade, P. A.; Aretxaga, I.; Austermann, J.; Bock, J. J.; Hughes, D.; Kang, Y.; Kim, S.; Lowenthal, J.; Mauskopf, P.; Scott, K.; Wilson, G.

    2006-12-01

    The Cosmic Evolution Survey (COSMOS) is a 2 square degree HST/ACS survey specifically designed to probe galaxy evolution as a function of time and environment (PI: N. Scoville). In addition to the extensive HST data, the COSMOS team has acquired deep multi-wavelength data from radio to X-ray (VLA, Spitzer, NOAO, CFHT, Subaru, Galex, Chandra, XMM). Spectroscopic surveys are currently under way using Magellan, Kecks, and VLT, and an extensive photometric redshift database is also being assembled. Future surveys using major new instruments such as Herschel are also being planned. To take advantage of these rich complementary databases, we have undertaken a 1100 micron imaging survey of a 30' x 30' field centered just north of the earlier mm/submm surveys by the Bolocam on CSO and MAMBO on the 30-m telescope, with a small overlap. We will present some of the preliminary results from the survey.

  12. Survey research and societal change.

    PubMed

    Tourangeau, Roger

    2004-01-01

    Surveys reflect societal change in a way that few other research tools do. Over the past two decades, three developments have transformed surveys. First, survey organizations have adopted new methods for selecting telephone samples; these new methods were made possible by the creation of large databases that include all listed telephone numbers in the United States. A second development has been the widespread decline in response rates for all types of surveys. In the face of this problem, survey researchers have developed new theories of nonresponse that build on the persuasion literature in social psychology. Finally, surveys have adopted many new methods of data collection; the new modes reflect technological developments in computing and the emergence of the Internet. Research has spawned several theories that examine how characteristics of the data collection method shape the answers obtained. Rapid change in survey methods is likely to continue in the coming years.

  13. Volumetric Survey Speed: A Figure of Merit for Transient Surveys

    NASA Astrophysics Data System (ADS)

    Bellm, Eric C.

    2016-08-01

    Time-domain surveys can exchange sky coverage for revisit frequency, complicating the comparison of their relative capabilities. By using different revisit intervals, a specific camera may execute surveys optimized for discovery of different classes of transient objects. We propose a new figure of merit, the instantaneous volumetric survey speed, for evaluating transient surveys. This metric defines the trade between cadence interval and snapshot survey volume and so provides a natural means of comparing survey capability. The related metric of areal survey speed imposes a constraint on the range of possible revisit times: we show that many modern time-domain surveys are limited by the amount of fresh sky available each night. We introduce the concept of “spectroscopic accessibility” and discuss its importance for transient science goals requiring followup observing. We present an extension of the control time algorithm for cases where multiple consecutive detections are required. Finally, we explore how survey speed and choice of cadence interval determine the detection rate of transients in the peak absolute magnitude-decay timescale phase space.

  14. Volumetric Survey Speed: A Figure of Merit for Transient Surveys

    NASA Astrophysics Data System (ADS)

    Bellm, Eric C.

    2016-08-01

    Time-domain surveys can exchange sky coverage for revisit frequency, complicating the comparison of their relative capabilities. By using different revisit intervals, a specific camera may execute surveys optimized for discovery of different classes of transient objects. We propose a new figure of merit, the instantaneous volumetric survey speed, for evaluating transient surveys. This metric defines the trade between cadence interval and snapshot survey volume and so provides a natural means of comparing survey capability. The related metric of areal survey speed imposes a constraint on the range of possible revisit times: we show that many modern time-domain surveys are limited by the amount of fresh sky available each night. We introduce the concept of “spectroscopic accessibility” and discuss its importance for transient science goals requiring followup observing. We present an extension of the control time algorithm for cases where multiple consecutive detections are required. Finally, we explore how survey speed and choice of cadence interval determine the detection rate of transients in the peak absolute magnitude–decay timescale phase space.

  15. The BRITE spectropolarimetric survey

    NASA Astrophysics Data System (ADS)

    Neiner, C.; Lèbre, A.

    2014-12-01

    The BRITE constellation of nanosatellites observes very bright stars to perform seismology. We have set up a spectropolarimetric survey of all BRITE targets, i.e. all ˜600 stars brighter than V=4, with Narval at TBL, ESPaDOnS at CFHT and HarpsPol at ESO. We plan to reach a magnetic detection threshold of B_{pol} = 50 G for stars hotter than F5 and B_{pol} = 5 G for cooler stars. This program will allow us to combine magnetic information with the BRITE seismic information and obtain a better interpretation and modelling of the internal structure of the stars. It will also lead to new discoveries of very bright magnetic stars, which are unique targets for follow-up and multi-technique studies.

  16. Generic Airspace Survey

    NASA Technical Reports Server (NTRS)

    Mogford, Richard H.; Bridges, Wayne; Gujarl, Vimmy; Lee, Paul U.; Preston, William

    2013-01-01

    This paper reports on an extension of generic airspace research to explore the amount of memorization and specialized skills required to manage sectors with specific characteristics or factors. Fifty-five retired controllers were given an electronic survey where they rated the amount of memorization or specialized skills needed for sixteen generic airspace factors. The results suggested similarities in the pattern of ratings between different areas of the US (East, Central, and West). The average of the ratings for each area also showed some differences between regions, with ratings being generally higher in the East area. All sixteen factors were rated as moderately to highly important and may be useful for future research on generic airspace, air traffic controller workload, etc.

  17. Deep Imaging Survey

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This is the first Deep Imaging Survey image taken by NASA's Galaxy Evolution Explorer. On June 22 and 23, 2003, the spacecraft obtained this near ultraviolet image of the Groth region by adding multiple orbits for a total exposure time of 14,000 seconds. Tens of thousands of objects can be identified in this picture.

    The Galaxy Evolution Explorer mission is led by the California Institute of Technology, which is also responsible for the science operations and data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of Caltech, manages the mission and built the science instrument. The mission was developed under NASA's Explorers Program, managed by the Goddard Space Flight Center, Greenbelt, Md. The mission's international partners include South Korea and France.

  18. Remote vehicle survey tool

    SciTech Connect

    Armstrong, G.A.; Burks, B.L.; Kress, R.L.; Wagner, D.G.; Ward, C.R.

    1993-05-01

    The Remote Vehicle Survey Tool (RVS7) is a color graphical display tool for viewing remotely acquired scientific data. The RVST displays the data in the form of a color two-dimensional world model map. The world model map allows movement of the remote vehicle to be tracked by the operator and the data from sensors to be graphically depicted in the interface. Linear and logarithmic meters, dual channel oscilloscopes, and directional compasses are used to display sensor information. The RVST is user-configurable by the use of ASCII text files. The operator can configure the RVST to work with any remote data acquisition system and teleoperated or autonomous vehicle. The modular design of the RVST and its ability to be quickly configured for varying system requirements make the RVST ideal for remote scientific data display in all environmental restoration and waste management programs.

  19. Remote vehicle survey tool

    SciTech Connect

    Armstrong, G.A.; Burks, B.L.; Kress, R.L. ); Wagner, D.G.; Ward, C.R. )

    1993-01-01

    The Remote Vehicle Survey Tool (RVS7) is a color graphical display tool for viewing remotely acquired scientific data. The RVST displays the data in the form of a color two-dimensional world model map. The world model map allows movement of the remote vehicle to be tracked by the operator and the data from sensors to be graphically depicted in the interface. Linear and logarithmic meters, dual channel oscilloscopes, and directional compasses are used to display sensor information. The RVST is user-configurable by the use of ASCII text files. The operator can configure the RVST to work with any remote data acquisition system and teleoperated or autonomous vehicle. The modular design of the RVST and its ability to be quickly configured for varying system requirements make the RVST ideal for remote scientific data display in all environmental restoration and waste management programs.

  20. Nonintrusive subsurface surveying capability

    SciTech Connect

    Tunnell, T.W.; Cave, S.P.

    1994-06-01

    This presentation describes the capabilities of a ground-pentrating radar (GPR) system developed by EG&G Energy Measurements (EM), a prime contractor to the Department of Energy (DOE). The focus of the presentation will be on the subsurface survey of DOE site TA-21 in Los Alamos, New Mexico. EG&G EM developed the system for the Department of Defense. The system is owned by the Department of the Army and currently resides at KO in Albuquerque. EM is pursuing efforts to transfer this technology to environmental applications such as waste-site characterization with DOE encouragement. The Army has already granted permission to use the system for the waste-site characterization activities.

  1. World survey of CAM

    NASA Astrophysics Data System (ADS)

    Hatvany, J.; Merchant, M. E.; Rathmill, K.; Yoshikawa, H.

    The worldwide state of the art and development trends in CAM are surveyed, emphasizing flexible manufacturing systems (FMS), robotics, computer-aided process planning, and computer-aided scheduling. The use of FMS, NC machine tools, DNC systems, and unmanned and nearly unmanned factories, are discussed as the state of the art in the USA, Japan, Western Europe and Eastern Europe. For the same areas, trends are projected, including the use of graphics and languages in CAM, and metamorphic machine tools. A Delphi-type forecast and its conclusions are presented. A CAM system for manufacture is projected for 1985, the use of robots equalling humans in assembly capability for 1990, and the fifty percent replacement of direct labor in automobile final assembly by programmable automation by 1995. An attempt is made to outline a methodical approach to forecasting the development of CAM over the next 10-15 years. Key issues in CAM proliferation, including financial and social aspects, are addressed.

  2. Quarry Haul Road Ecological Survey

    SciTech Connect

    Not Available

    1992-09-01

    This biological survey was performed to document the summer flora and fauna found along the haul road constructed as part of the remedial action for the quarry bulk waste. State and Federal species listed as threatened or endangered were noted if encountered while surveying. Sampling locations were equally spaced along the quarry haul road, and a survey for vegetation and birds conducted at each location. Bird observations were conducted as breeding bird surveys once in June of 1991, and again in June of 1992. Each year's survey includes two observations in the early morning and one late in the evening. Vegetation surveys were conducted in 1991 using quadrants and transects. mammal, reptile, and amphibian sightings were noted as encountered.

  3. PEP surveying procedures and equipment

    SciTech Connect

    Linker, F.

    1982-06-01

    The PEP Survey and Alignment System, which employs both laser-based and optical survey methods, is described. The laser is operated in conjunction with the Tektronix 4051 computer and surveying instruments such as ARM and SAM, system which is designed to automate data input, reduction, and production of alignment instructions. The laser system is used when surveying ring quadrupoles, main bend magnets, sextupoles, and is optional when surveying RF cavities and insertion quadrupoles. Optical methods usually require that data be manually entered into the computer for alignment, but in some cases, an element can be aligned using nominal values of fiducial locations without use of the computer. Optical surveying is used in the alignment of NIT and SIT, low field bend magnets, wigglers, RF cavities, and insertion quadrupoles.

  4. Questionnaire Surveys: Four Survey Instruments in Educational Research.

    ERIC Educational Resources Information Center

    Inoue, Yukiko

    This paper presents four questionnaire surveys administered in educational research. Each of the questionnaires is followed by a brief research report with an abstract and summary statistics. The first survey, "Guam Undergraduate Women Questionnaire," explores the status aspiration and gender awareness of undergraduate women in Guam. Responses of…

  5. ASHA Survey of Health Curriculum Needs: Survey Results.

    ERIC Educational Resources Information Center

    Schneider, Livingston S.; Thier, Herbert D.

    The results of a survey conducted by the Ad hoc Committee to Study the Needs and Problems of the Classroom Teacher in Curriculum Development are reported. Questionnaires were sent to members of the American School Health Association (ASHA). The survey was composed of four sections: (1) background information on demographic data, institutional…

  6. Survey Series: College Employees. Survey Series, Fall 2000.

    ERIC Educational Resources Information Center

    Mery, Pamela M.

    In 2000, the City College of San Francisco (CCSF) surveyed faculty, administration, and staff members regarding 64 campus services. All employees received the survey, and nearly 30% (849) responded. The services were rated on a scale of 1 to 4, 1 being 'poor' and 4 being 'excellent.' Results included: (1) library services received the highest mean…

  7. Consumer Expenditure Survey: Interview Survey, 1984. Bulletin 2267.

    ERIC Educational Resources Information Center

    Bureau of Labor Statistics (DOL), Washington, DC.

    This bulletin presents detailed income and expenditure data for 1984 from the interview component of the ongoing Consumer Expenditure Survey. Data in this bulletin are for the urban population. Text tables include the following: (1) annual expenditures of urban consumer units, and percent change in consumer expenditures, Interview Survey and…

  8. Survey report: Senegal.

    PubMed

    Kent, M M

    1988-02-01

    Senegal, situated on the west coast of Africa, has a history of high fertility and high infant mortality. Preliminary results of the 1986 Demographic and Health Survey (DHS), administered by the Institute for Resource Development, Columbia, Md., indicate a slight decline in the birth rate and reveal a high prevalence of child health problems associated with poor sanitation and nutrition. Senegal's 7.1 million people (1987 estimate) are unevenly distributed throughout the country's dry, flat landscape. Some 40% of the population is urban, and about 1/2 of these urban residents live in the capital, Dakar. Heavy rural-to-urban migration has been encouraged by the high population growth rate--2.8% annually--and a poor standard of living in the countryside. With about 70% of the labor force dependent on agriculture, a drought-related drop in the yields of groundnuts and other cash crops contributed to the rural exodus and to growing unemployment in the capital. The 1986 survey of family planning and child health collected information from 4415 women 15-49 years of age, and measured the height and weight of their children between 6 and 36 months. The findings suggest that fertility may have fallen slightly since 1978. The Senegal DHS recorded a total fertility rate (TFR) of 6.5 average births/woman during the 1981 Senegal World Fertility Survey (WFS). The DHS also found that women at the end of their childbearing--age 45-49 in 1986--had borne 7.4 children on average, further evidence of a slight decline in births among the younger women. Senegalese women marry young. The average age at 1st marriage is only 16.1, according to the 1986 DHS, and family planning within marriage is not widely accepted. In 1986, 11.7% of the currently married women 15-49 used some form of birth control, but only 2.7% used a modern method. While this is a large increase over the 3.9% rate of contraceptive use recorded in the 1978 WFS, almost 3/4 of the gain was due to a higher reported use of

  9. User Surveys. SPEC Kit 148.

    ERIC Educational Resources Information Center

    Engelbrecht, Pamela Noyes

    Based on responses to a survey of Association of Research Libraries (ARL) members in March 1988, this Systems and Procedures Exchange Center (SPEC) flyer and kit are designed to assist administrators of large academic libraries in the selection of useful methods of conducting user surveys for particular library concerns. The flyer provides a brief…

  10. The Survey: Improving Its Usefulness.

    ERIC Educational Resources Information Center

    Brown, Roberta D.

    Attrition at the Arkansas College, a small independent institution, was studied through a survey of former students. Respondents were asked to reflect upon their college experience in relation to personal needs, academic and financial concerns, social life, services, and college life. The College Experience Survey and the Rate of Attrition…

  11. Grading Philosophy Survey, Fall 1989.

    ERIC Educational Resources Information Center

    Catonsville Community Coll., MD. Office of Institutional Research.

    In 1989, a survey was conducted at Catonsville Community College to establish a consensus about the underlying philosophy governing the college's grading policy. The survey respondents included 167 full-time or adjunct faculty members, 15 student personnel professionals, 8 administrators, and 6 library, media, or telecommunications professionals.…

  12. Surveying Students about Controversial Subjects

    ERIC Educational Resources Information Center

    Soronen, Lisa E.

    2007-01-01

    Background: Because of school districts' interest in best serving the health needs of students, many choose to administer surveys addressing controversial topics. Administering such surveys in a voluntary and anonymous manner may help reduce conflict. Methods: This is a review of 2 recent federal court of appeals decisions regarding surveying…

  13. The Fiscal Survey of States.

    ERIC Educational Resources Information Center

    National Governors' Association, Washington, DC.

    Findings of the 1992 Fiscal Survey of the States, published biannually are presented in this document. The survey presents aggregate and individual data on the states' general fund receipts, expenditures, and balances. Although not the totality of state spending, these funds are used to finance most broad-based state services and are the most…

  14. Positioning Fixture For Survey Antenna

    NASA Technical Reports Server (NTRS)

    Dinardo, Steven J.; Smith, Mark A.

    1994-01-01

    Improved positioning fixture designed to simplify and accelerate accurate alignment of antenna for use in land survey aided by satellites of Global Positioning System. Holds antenna at fixed height and orientation over station monument so survey measurements made with accuracy and precision.

  15. Cuesta College Student Withdrawal Survey.

    ERIC Educational Resources Information Center

    Hagen, Peter F.; Cartnal, Ryan

    The spring 1999 student withdrawal survey was made available for approximately two weeks before the final withdrawal deadline to all students who formally dropped a class through the admissions office at either the North County or San Luis Obsipo campus of Cuesta College in California. A total of 438 useable surveys were collected. The identical…

  16. Conducting Surveys on Sensitive Topics

    ERIC Educational Resources Information Center

    Pryor, John H.

    2004-01-01

    Many institutions are surveying students about sensitive topics such as alcohol and drug use, sexual behavior, and academic dishonesty. Yet these can be some of the most difficult surveys to administer successfully, given reluctance on the part of respondents both to participate and to provide truthful answers. (Contains 1 table.)

  17. Californians & Education. PPIC Statewide Survey

    ERIC Educational Resources Information Center

    Baldassare, Mark; Bonner, Dean; Petek, Sonja; Shrestha, Jui

    2011-01-01

    The Public Policy Institute of California (PPIC) Statewide Survey series provides policymakers, the media, and the public with objective, advocacy-free information on the perceptions, opinions, and public policy preferences of California residents. Inaugurated in April 1998, this is the 116th PPIC Statewide Survey in a series that has generated a…

  18. Treating Globalization in History Surveys

    ERIC Educational Resources Information Center

    Stearns, Peter N.

    2003-01-01

    Globalization provides history teachers with an opportunity to link past to present in new ways and to test historical thinking. This is particularly true in world history surveys, but has relevance to Western civilization or United States history surveys as well. For globalization in turn, the historical perspective offers opportunities for more…

  19. Masters of All They Survey

    ERIC Educational Resources Information Center

    Fredette, Michelle

    2012-01-01

    This article discusses a survey tool, known as TechQual+, which gives IT leaders a quick and easy way to gauge their departments' performance on campus and learn what matters to their constituents, including faculty, students, and staff. The idea of an IT survey tool that can be used across higher education has its skeptics, who feel that colleges…

  20. Michigan School Privatization Survey 2007

    ERIC Educational Resources Information Center

    Smith, Daniel J.; LaFaive, Michael D.

    2007-01-01

    From April 25 through June 30, 2007, the Mackinac Center for Public Policy conducted its fifth survey of the privatization of bus, food and janitorial services among Michigan's 552 conventional public school districts. All Michigan school districts responded. In 2007, the Mackinac Center also conducted a nationwide survey of state education…

  1. Frederick County Community Perception Survey.

    ERIC Educational Resources Information Center

    Frederick Community Coll., MD.

    In 1997, Frederick Community College (FCC) in Maryland conducted a telephone survey of a random sample of 466 Frederick County residents to identify their perceptions of the college. In particular, the survey examined Frederick County residents' image of FCC, level of awareness of services and programs offered by FCC, and the types of services…

  2. Californians & Education. PPIC Statewide Survey

    ERIC Educational Resources Information Center

    Baldassare, Mark; Bonner, Dean; Petek, Sonja; Shrestha, Jui

    2014-01-01

    The Public Policy Institute of California (PPIC) Statewide Survey provides policymakers, the media, and the public with objective, advocacy-free information on the perceptions, opinions, and public policy preferences of California residents. This is the 141st PPIC Statewide Survey in a series that was inaugurated in April 1998 and has generated a…

  3. Californians & Education. PPIC Statewide Survey

    ERIC Educational Resources Information Center

    Baldassare, Mark; Bonner, Dean; Petek, Sonja; Shrestha, Jui

    2012-01-01

    The Public Policy Institute of California (PPIC) Statewide Survey provides policymakers, the media, and the public with objective, advocacy-free information on the perceptions, opinions, and public policy preferences of California residents. Inaugurated in April 1998, this is the 125th PPIC Statewide Survey in a series that has generated a…

  4. Californians & Education. PPIC Statewide Survey

    ERIC Educational Resources Information Center

    Baldassare, Mark; Bonner, Dean; Petek, Sonja; Willcoxon, Nicole

    2010-01-01

    This edition of the PPIC (Public Policy Institute of California) Statewide Survey is the sixth in a series of surveys funded by The William and Flora Hewlett Foundation focusing on K-12 education issues. Its goal is to inform state policymakers, encourage discussion, and raise public awareness about a variety of K-12, higher education,…

  5. A Survey of Collectives

    NASA Technical Reports Server (NTRS)

    Tumer, Kagan; Wolpert, David

    2004-01-01

    Due to the increasing sophistication and miniaturization of computational components, complex, distributed systems of interacting agents are becoming ubiquitous. Such systems, where each agent aims to optimize its own performance, but where there is a well-defined set of system-level performance criteria, are called collectives. The fundamental problem in analyzing/designing such systems is in determining how the combined actions of self-interested agents leads to 'coordinated' behavior on a iarge scale. Examples of artificial systems which exhibit such behavior include packet routing across a data network, control of an array of communication satellites, coordination of multiple deployables, and dynamic job scheduling across a distributed computer grid. Examples of natural systems include ecosystems, economies, and the organelles within a living cell. No current scientific discipline provides a thorough understanding of the relation between the structure of collectives and how well they meet their overall performance criteria. Although still very young, research on collectives has resulted in successes both in understanding and designing such systems. It is eqected that as it matures and draws upon other disciplines related to collectives, this field will greatly expand the range of computationally addressable tasks. Moreover, in addition to drawing on them, such a fully developed field of collective intelligence may provide insight into already established scientific fields, such as mechanism design, economics, game theory, and population biology. This chapter provides a survey to the emerging science of collectives.

  6. The Little Things Survey

    NASA Astrophysics Data System (ADS)

    Hunter, Deidre Ann; LITTLE THINGS Team

    2012-01-01

    We have assembled a multi-wavelength dataset on 41 relatively normal, nearby (<10 Mpc) gas-rich dwarf irregular galaxies for the purpose of determining the drivers for star formation in these systems. This project is called LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey). Our data include GALEX UV images, ground-based UBV and Halpha images, some ground-based JHK images, Spitzer archival mid-IR images, and HI-line maps. The HI maps, obtained with the VLA, go deep (12/6/2 hrs in B/C/D arrays) and are characterized by high spectral resolution (

  7. The LITTLE THINGS Survey

    NASA Astrophysics Data System (ADS)

    Rupen, Michael P.; LITTLE THINGS Team

    2010-01-01

    The processes that lead to star formation on galactic scales are poorly understood even in the simplest systems in the universe, dwarf galaxies. At best we have incomplete knowledge of certain processes in certain environments. Here we present preliminary HI images of a small subset of galaxies from the LITTLE THINGS Survey: a complete dataset on a sample of 41 dIm galaxies chosen to span a range of luminosities. We are tracing their stellar populations, gas content, dynamics, and star formation indicators. We were granted over 300 hours of time with the VLA in B, C, and D array configurations to obtain deep HI-line maps of the sample with high angular and velocity resolution to combine with our optical, UV, and IR data to answer the following questions: 1) What regulates cloud/star formation in tiny galaxies? 2) How is star formation occurring in the outer parts of dwarf galaxies, where the gas is gravitationally stable? 3) What happens to the star formation process at breaks in the exponential stellar light profiles? 4) And, what is going on with Blue Compact Dwarfs? More information can be found at http://www.lowell.edu/users/dah/littlethings/. We gratefully acknowledge funding for this research from the National Science Foundation with grants to DAH (AST-0707563) and CES (AST-0707468). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  8. Diffuse Microwave Emission Survey

    NASA Astrophysics Data System (ADS)

    Shafer, R. A.; Mather, J.; Kogut, A.; Fixsen, D. J.; Seiffert, M.; Lubin, P. M.; Levin, S. M.

    1996-12-01

    The Diffuse Microwave Emission Survey (DIMES) is a mission concept selected by NASA in 1995 to answer fundamental questions about the content and history of the universe. DIMES will use a set of absolutely calibrated cryogenic radiometers from a space platform to measure the frequency spectrum of the cosmic microwave background (CMB) at wavelengths 15--0.3 cm (frequency 2--100 GHz) to precision 0.1 mK or better. Measurements at centimeter wavelengths probe different physical processes than the COBE-FIRAS spectra at shorter wavelengths, and complement the anisotropy measurements from DMR, balloon and ground-based instruments, and the planned MAP and COBRAS/SAMBA satellites. DIMES will observe the free-free signal from early photoionization to establish the precise epoch of structure formation, and will measure or limit energy release at redshift 10(4) < z < 10(7) by measuring the chemical potential distortion of the CMB spectrum. Both are likely under current cosmological theory and allowed by current measurement limits; even an upper limit at the expected sensitivity 10(-5) MJy/sr will place important constraints on the matter content, structure, and evolution of the universe. Detecting these distortions or showing that they do not exist constitutes the last frontier of CMB observations.

  9. The Impact of Surveys

    NASA Astrophysics Data System (ADS)

    Rampazzo, Roberto; D'Onofrio, Mauro; Zaggia, Simone; Paturel, George; Boselli, Alessandro; Ferrarese, Laura; Poggianti, Bianca M.; Bergvall, Nils A. S.; Karachentseva, Valentina; Haynes, Martha P.; Giovanelli, Riccardo; Bianchi, Luciana; Trinchieri, Ginevra; Bland-Hawthorn, Jonathan

    Since the most ancient times astronomers felt the need to collect and list in atlases and catalogs all the visible objects in the sky. The first stellar catalog known in the western world being the one of Hipparchus (second century BC). Hypparchus of Nicea We have to wait until Charles Messier Messier Charles at the end of the eighteenth century to have the first incidental catalog of nebulae, i.e. including a mixture of fuzzy objects, nebulæ, that telescopes of the epoch could detect. In Chap. 1 we have already discussed the atlases and catalogs that soon after the discovery of galaxies appeared in the literature describing the properties of the nearby galaxies, in particular their morphologies in Chap. 3 . The subject of extragalactic papers, during the photographic plate era, was one or few galaxies, whose properties were carefully scrutinized looking at all the details resolved by telescopes in the optical waveband. This happens also today, of course, basically at all wavelengths. However, the impact of new technologies permits in the last two decades to tackle survey programs addressed to the study of specific extragalactic problems considering millions of galaxies.

  10. And the Survey Says ...

    NASA Astrophysics Data System (ADS)

    White, Susan C.

    2013-10-01

    Two-Year Colleges, Physics Majors, and Diversity As noted last month, we're taking a look at physics in two-year colleges (TYCs). We expect to have the first reports from our 2012-13 Nationwide Survey of High School Physics Teachers in the spring of 2014. Last month we noted that the high school physics experience of undergraduate physics majors was quite different for students who started at a TYC and those who did not. That is not the only difference we saw. Nine percent of the physics undergraduate seniors in 2007 had started their college education at a TYC. These students are more racially diverse: about 20% of those who started at a TYC were Hispanic or a non-Asian minority. (African Americans are included in this group.) While about one physics major in 11 started at a TYC, the ratio for Hispanic and non-Asian minorities was about one in six. The Hispanics and non-Asian minority physics majors were almost twice as likely to have started at a TYC. In the November issue, we'll look at physics offerings in TYCs.

  11. The Qatar Exoplanet Survey

    NASA Astrophysics Data System (ADS)

    Alsubai, K. A.; Parley, N. R.; Bramich, D. M.; Horne, K.; Collier Cameron, A.; West, R. G.; Sorensen, P. M.; Pollacco, D.; Smith, J. C.; Fors, O.

    2013-12-01

    The Qatar Exoplanet Survey (QES) is discovering hot Jupiters and aims to discover hot Saturns and hot Neptunes that transit in front of relatively bright host stars. QES currently operates a robotic wide-angle camera system to identify promising transiting exoplanet candidates among which are the confirmed exoplanets Qatar 1b and 2b. This paper describes the first generation QES instrument, observing strategy, data reduction techniques, and follow-up procedures. The QES cameras in New Mexico complement the SuperWASP cameras in the Canary Islands and South Africa, and we have developed tools to enable the QES images and light curves to be archived and analysed using the same methods developed for the SuperWASP datasets. With its larger aperture, finer pixel scale, and comparable field of view, and with plans to deploy similar systems at two further sites, the QES, in collaboration with SuperWASP, should help to speed the discovery of smaller radius planets transiting bright stars in northern skies.

  12. The LITTLE THINGS Survey

    NASA Astrophysics Data System (ADS)

    Hunter, Deidre Ann; LITTLE THINGS Team

    2012-01-01

    We have assembled a multi-wavelength dataset on 41 relatively normal, nearby (<10 Mpc) gas-rich dwarf irregular galaxies for the purpose of determining the drivers for star formation in these systems. This project is called LITTLE THINGS (Local Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey). Our data include GALEX UV images, ground-based UBV and Halpha images, some ground-based JHK images, Spitzer archival mid-IR images, and HI-line maps. The HI maps, obtained with the VLA, go deep (12/6/2 hrs in B/C/D arrays) and are characterized by high spectral resolution (

  13. 42 CFR 488.725 - Unannounced surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Unannounced surveys. 488.725 Section 488.725 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Home Health Agencies § 488.725 Unannounced surveys. (a) Basic rule. All HHA surveys must be...

  14. 42 CFR 488.7 - Validation survey.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Validation survey. 488.7 Section 488.7 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES General Provisions § 488.7 Validation survey. (a) Basis for survey. CMS may require a survey of an accredited provider or supplier...

  15. 42 CFR 488.720 - Extended surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Extended surveys. 488.720 Section 488.720 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Home Health Agencies § 488.720 Extended surveys. (a) Purpose of survey. The purpose of an...

  16. 42 CFR 488.305 - Standard surveys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Standard surveys. 488.305 Section 488.305 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.305 Standard surveys. (a) For each SNF and NF, the State survey...

  17. 42 CFR 488.7 - Validation survey.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Validation survey. 488.7 Section 488.7 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES General Provisions § 488.7 Validation survey. (a) Basis for survey. CMS may require a survey of an accredited provider or supplier...

  18. 42 CFR 488.305 - Standard surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Standard surveys. 488.305 Section 488.305 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.305 Standard surveys. (a) For each SNF and NF, the State survey...

  19. 42 CFR 488.720 - Extended surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Extended surveys. 488.720 Section 488.720 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Home Health Agencies § 488.720 Extended surveys. (a) Purpose of survey. The purpose of an...

  20. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  1. 42 CFR 488.7 - Validation survey.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Validation survey. 488.7 Section 488.7 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES General Provisions § 488.7 Validation survey. (a) Basis for survey. CMS may require a survey of an accredited provider or supplier...

  2. 42 CFR 488.725 - Unannounced surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Unannounced surveys. 488.725 Section 488.725 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Home Health Agencies § 488.725 Unannounced surveys. (a) Basic rule. All HHA surveys must be...

  3. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  4. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  5. 42 CFR 488.7 - Validation survey.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Validation survey. 488.7 Section 488.7 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES General Provisions § 488.7 Validation survey. (a) Basis for survey. CMS may require a survey of an accredited provider or supplier...

  6. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  7. 42 CFR 488.7 - Validation survey.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Validation survey. 488.7 Section 488.7 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES General Provisions § 488.7 Validation survey. (a) Basis for survey. CMS may require a survey of an accredited provider or supplier...

  8. 42 CFR 488.305 - Standard surveys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Standard surveys. 488.305 Section 488.305 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.305 Standard surveys. (a) For each SNF and NF, the State survey...

  9. 42 CFR 488.305 - Standard surveys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Standard surveys. 488.305 Section 488.305 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.305 Standard surveys. (a) For each SNF and NF, the State survey...

  10. 42 CFR 488.310 - Extended survey.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Extended survey. 488.310 Section 488.310 Public...) STANDARDS AND CERTIFICATION SURVEY, CERTIFICATION, AND ENFORCEMENT PROCEDURES Survey and Certification of Long-Term Care Facilities § 488.310 Extended survey. (a) Purpose of survey. The purpose of an...

  11. Innovations in national nutrition surveys.

    PubMed

    Stephen, Alison M; Mak, Tsz Ning; Fitt, Emily; Nicholson, Sonja; Roberts, Caireen; Sommerville, Jill

    2013-02-01

    The aim of this paper is to describe innovations taking place in national nutrition surveys in the UK and the challenges of undertaking innovations in such settings. National nutrition surveys must be representative of the overall population in characteristics such as socio-economic circumstances, age, sex and region. High response rates are critical. Dietary assessment innovations must therefore be suitable for all types of individuals, from the very young to the very old, for variable literacy and/or technical skills, different ethnic backgrounds and life circumstances, such as multiple carers and frequent travel. At the same time, national surveys need details on foods consumed. Current advances in dietary assessment use either technological innovations or simplified methods; neither lend themselves to national surveys. The National Diet and Nutrition Survey (NDNS) rolling programme, and the Diet and Nutrition Survey of Infants and Young Children (DNSIYC), currently use the 4-d estimated diary, a compromise for detail and respondent burden. Collection of food packaging enables identification of specific products. Providing space for location of eating, others eating, the television being on and eating at a table, adds to eating context information. Disaggregation of mixed dishes enables determination of true intakes of meat and fruit and vegetables. Measurement of nutritional status requires blood sampling and processing in DNSIYC clinics throughout the country and mobile units were used to optimise response. Hence, innovations in national surveys can and are being made but must take into account the paramount concerns of detail and response rate.

  12. Quantifying bias in a health survey: modeling total survey error in the national immunization survey.

    PubMed

    Molinari, NoelleAngelique M; Wolter, Kirk M; Skalland, Benjamin; Montgomery, Robert; Khare, Meena; Smith, Philip J; Barron, Martin L; Copeland, Kennon; Santos, Kathleen; Singleton, James A

    2011-02-28

    Random-digit-dial telephone surveys are experiencing both declining response rates and increasing under-coverage due to the prevalence of households that substitute a wireless telephone for their residential landline telephone. These changes increase the potential for bias in survey estimates and heighten the need for survey researchers to evaluate the sources and magnitudes of potential bias. We apply a Monte Carlo simulation-based approach to assess bias in the NIS, a land-line telephone survey of 19-35 month-old children used to obtain national vaccination coverage estimates. We develop a model describing the survey stages at which component nonsampling error may be introduced due to nonresponse and under-coverage. We use that model and components of error estimated in special studies to quantify the extent to which noncoverage and nonresponse may bias the vaccination coverage estimates obtained from the NIS and present a distribution of the total survey error. Results indicated that the total error followed a normal distribution with mean of 1.72 per cent(95 per cent CI: 1.71, 1.74 per cent) and final adjusted survey weights corrected for this error. Although small, the largest contributor to error in terms of magnitude was nonresponse of immunization providers. The total error was most sensitive to declines in coverage due to cell phone only households. These results indicate that, while response rates and coverage may be declining, total survey error is quite small. Since response rates have historically been used to proxy for total survey error, the finding that these rates do not accurately reflect bias is important for evaluation of survey data. Published in 2011 by John Wiley & Sons, Ltd. PMID:21294147

  13. The Cardiff health survey: teaching survey methodology by participation.

    PubMed

    Lewis, P A; Charny, M

    1987-01-01

    Medical students were taught survey methodology by participating in all phases of a large community survey. The survey examined health beliefs, knowledge and behaviour in a sample of 5150 people drawn from the electoral register of the City of Cardiff. The study achieved several educational objectives for the medical students: they met well people in their own homes and had an opportunity to get to know a community; by taking part in a study from the initial phases to the conclusion they could appreciate the context of the theoretical teaching they were being given concurrently in their undergraduate course; they learnt to analyse raw data and produce reports; and they gained insights into the health knowledge, behaviour, attitudes and beliefs of a population. In addition, the survey produced a substantial quantity of valuable data which staff and students are analysing and intend to publish. PMID:3423507

  14. The Cardiff health survey: teaching survey methodology by participation.

    PubMed

    Lewis, P A; Charny, M

    1987-01-01

    Medical students were taught survey methodology by participating in all phases of a large community survey. The survey examined health beliefs, knowledge and behaviour in a sample of 5150 people drawn from the electoral register of the City of Cardiff. The study achieved several educational objectives for the medical students: they met well people in their own homes and had an opportunity to get to know a community; by taking part in a study from the initial phases to the conclusion they could appreciate the context of the theoretical teaching they were being given concurrently in their undergraduate course; they learnt to analyse raw data and produce reports; and they gained insights into the health knowledge, behaviour, attitudes and beliefs of a population. In addition, the survey produced a substantial quantity of valuable data which staff and students are analysing and intend to publish.

  15. Geophex airborne unmanned survey system

    SciTech Connect

    Won, I.J.; Taylor, D.W.A.

    1995-03-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected.

  16. Cosmology with photometric redshift surveys

    NASA Astrophysics Data System (ADS)

    Blake, Chris; Bridle, Sarah

    2005-11-01

    We explore the utility of future photometric redshift imaging surveys for delineating the large-scale structure of the Universe, and assess the resulting constraints on the cosmological model. We perform the following two complementary types of analysis. (i) We quantify the statistical confidence and the accuracy with which such surveys will be able to detect and measure characteristic features in the clustering power spectrum such as the acoustic oscillations and the turnover, in a `model-independent' fashion. We show for example that a 10000-deg2 imaging survey with depth r= 22.5 and photometric redshift accuracy δz/(1 +z) = 0.03 will detect the acoustic oscillations with 99.9 per cent confidence, measuring the associated preferred cosmological scale with 2 per cent precision. Such a survey will also detect the turnover with 95 per cent confidence, determining the corresponding scale with 20 per cent accuracy. (ii) By assuming a Λ cold dark matter (ΛCDM) model power spectrum we calculate the confidence with which a non-zero baryon fraction can be deduced from such future galaxy surveys. We quantify `wiggle detection' by calculating the number of standard deviations by which the baryon fraction is measured, after marginalizing over the shape parameter. This is typically a factor of 4 more significant (in terms of number of standard deviations) than the above `model-independent' result. For both analyses, we quantify the variation of the results with magnitude depth and photometric redshift precision, and discuss the prospects for obtaining the required performance with realistic future surveys. We conclude that the precision with which the clustering pattern may be inferred from future photometric redshift surveys will be competitive with contemporaneous spectroscopic redshift surveys, assuming that systematic effects can be controlled. We find that for equivalent wiggle detection power, a photometric redshift survey requires an area approximately 12[δz/(1 +z

  17. Simulated LSST Mini-Surveys

    NASA Astrophysics Data System (ADS)

    Ridgway, Stephen T.; LSST Operations Simulator Group

    2013-01-01

    The LSST operations simulator has been used to explore a range of possible mini-surveys which could be carried out within a 30 day window. Such opportunities may exist during LSST commissioning, as companion or constituent elements of the 10-year main survey, or as potential follow-on programs after the completion of the main program. Mini-surveys could achieve increased depth or more intensive cadences by covering a reduced sky area. The predicted performance, with respect to stacked depth and cadences realized, will be described for several distinctly different possible strategies.

  18. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.J.; Keiswetter, D.

    1995-10-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits rapid geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected.

  19. Science Archives: Facilitating Survey Science

    NASA Astrophysics Data System (ADS)

    Read, M.; Mann, B.; Blake, R.; Collins, R.; Cross, N.; Davenhall, C.; Holliman, M.; Sutorius, E.

    In this paper we discuss the role of science archives and data centres in supporting survey astronomy. We start by describing the work of the Wide Field Astronomy Unit (WFAU) at the Institute for Astronomy of the University of Edinburgh, which in recent years has built science archives for the current large area and deep infrared surveys (UKIDSS and VISTA). We then go on to briefly discuss, in more general terms, how archives should operate and service the current and ever increasing volume of digital survey data.

  20. MedlinePlus Survey Results 2015

    MedlinePlus

    ... medlineplus.gov/survey/index.html MedlinePlus Survey Results 2015 To use the sharing features on this page, ... to our online customer satisfaction site surveys in 2015, administered by the ForeSee by Answers Corporation. Learn ...