Science.gov

Sample records for 8gr8 cygnus survey

  1. 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

  2. An R- and I-band Photometric Variability Survey of the Cygnus OB2 Association

    NASA Astrophysics Data System (ADS)

    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 21farcm3 × 21farcm3 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 AV ≈ 20) that permeates much of the region. Here, we provide results of the first variability study with this combination of spatial coverage (~0.5 deg) and photometric depth (R ~ 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. Based on observations obtained using the 1.3 m McGraw-Hill telescope at the MDM Observatory.

  3. 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.

  4. 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).

  5. The {ital ROSAT} HRI x-ray survey of the Cygnus loop

    SciTech Connect

    Levenson, N.A.; Graham, J.R.; Aschenbach, B.; Blair, W.P.; Brinkmann, W.; Busser, J.; Egger, R.; Fesen, R.A.; Hester, J.J.; Kahn, S.M.; Klein, R.I. |; McKee, C.F. |; Petre, R.; Pisarski, R.; Raymond, J.C.; Snowden, S.L.

    1997-07-01

    We describe and report progress on the joint U.S. and German campaign to map the X-ray emission from the entire Cygnus Loop with the {ital ROSAT} High Resolution Imager. The Cygnus Loop is the prototype for a supernova remnant that is dominated by interactions with the interstellar medium and supplies fundamental physical information on this basic mechanism for shaping the interstellar medium. The global view that these high-resolution (FWHM{approximately}10{sup {prime}{prime}}) observations provide emphasizes the inhomogeneity of the interstellar medium and the pivotal nature of cloud{endash}blast-wave interactions in determining the X-ray morphology of the supernova remnant. While investigating the details of the evolution of the blast wave, we also describe the interstellar medium in the vicinity of the Cygnus Loop, which the progenitor star has processed. Although we do not expect the X-ray observations to be complete until 1997 September, the incomplete data combined with deep H{alpha} images provide definitive evidence that the Cygnus Loop was formed by an explosion within a preexisting cavity. {copyright} {ital 1997} {ital The American Astronomical Society}

  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

    SciTech Connect

    Kobulnicky, Henry A.; Lundquist, Michael J.; Burke, Jamison; Chapman, James; Keller, Erica; Lester, Kathryn; Rolen, Emily K.; Topel, Eric; Bhattacharjee, Anirban; Smullen, Rachel A.; Álvarez, Carlos A. Vargas; Runnoe, Jessie C.; Dale, Daniel A.; Brotherton, Michael M.; Kiminki, Daniel C. E-mail: jburke2@swarthmore.edu E-mail: kelle22e@mtholyoke.edu E-mail: emily.k.rolen@vanderbilt.edu

    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 ≅0.2, ≅0.4, and ≅1 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{sup –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. Cygnus PFL Switch Jitter

    SciTech Connect

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

    2007-07-21

    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 rads at 1 m, 50-ns full-widthhalf-maximum. 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 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, threecell inductive voltage adder, and rod-pinch diode. A primary source of fluctuation in Cygnus shot-to-shot performance may be 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 source X-ray spectrum and dose. Therefore, PFL switch jitter may contribute to shot-to-shot variation in these parameters, which are crucial to radiographic quality. In this paper we will present PFL switch jitter analysis for both Cygnus machines and present the correlation with dose. 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 the PFL switch performance for one larger switch gap setting will be examined.

  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. Complete mitochondrial genome of Cygnus cygnus (Aves, Anseriformes, Anatidae).

    PubMed

    Park, Chang Eon; Park, Gun-Seok; Kwak, Yunyoung; Hong, Sung-Jun; Rahim Khan, Abdur; Kwon Jung, Byung; Park, Yung-Jun; Kim, Jong-Guk; Cheon Park, Hee; Shin, Jae-Ho

    2016-07-01

    In this study, the complete mitochondrial genome of Cygnus cygnus (Aves, Anseriformes, Anatidae) was sequenced. The genome, consisting of 16 724 base pairs (bp), encoded 13 protein coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a control region (CR). Two rRNA genes for 12S rRNA (991 bases) and 16S rRNA (1608 bases) are located between tRNA-Phe and tRNA-Leu (UUR) and divided by the tRNA-Val. The CR, of 1156 bp in length, is located between tRNA-Glu and tRNA-Phe. The overall base composition of C. cygnus is G + C: 47.2%, A + T: 52.8%, apparently with a slight AT bias. Phylogenetic analysis showed that the C. cygnus was closed to Cygnus columbianus. PMID:26153753

  14. 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.

  15. 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.

  16. 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...

  17. Cygnus: Electrochemical cleaning

    SciTech Connect

    Simon, G.G.; Sokcic-Kostic, M.; Vujic, J.; Solly, F.; Johnson, D.; Philipp, D.

    2000-07-01

    Electrochemical cleaning, commonly referred to as electropolishing, can be used to remove surface contamination by dissolving the underlying metal matrix. This is accomplished in the Cygnus process by passing an electric current through a dilute, acidic electrolyte. In the operation, the surface is polished, thereby removing contamination and irregularities to prevent recontamination. Mechanical decontamination processes, by comparison, leave the surface layer distorted, highly stressed, and contaminated with process media. Techniques employing grinding and particle impingement rework the surface of malleable metals such as stainless steel, folding the contamination into pockets where material is released for uncontrolled use. Solway, Ltd., developed the method to be more effective with respect to waste reduction and cost-effectiveness. Together with NUKEM Nuklear, the method was improved for a decontamination procedure in nuclear technology. One of the applications was the decontamination work at KRN Grundremmingen in Germany. The intensive work has shown that the method is suitable for decontamination services in both defense and commercial areas.

  18. Cygnus Performance in Subcritical Experiments

    SciTech Connect

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

    2008-02-01

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources with the following specifications: 4-rad dose at 1 m, 1-mm spot size, 50-ns pulse length, 2.25-MeV endpoint energy. The facility is located in an underground tunnel complex at the Nevada Test Site. Here SubCritical Experiments (SCEs) are performed to study the dynamic properties of plutonium. The Cygnus sources were developed as a primary diagnostic for these tests. Since SCEs are single-shot, high-value events - reliability and reproducibility are key issues. Enhanced reliability involves minimization of failure modes through design, inspection, and testing. Many unique hardware and operational features were incorporated into Cygnus to insure reliability. Enhanced reproducibility involves normalization of shot-to-shot output also through design, inspection, and testing. The first SCE to utilize Cygnus, Armando, was executed on May 25, 2004. A year later, April - May 2005, calibrations using a plutonium step wedge were performed. The results from this series were used for more precise interpretation of the Armando data. In the period February - May 2007 Cygnus was fielded on Thermos, which is a series of small-sample plutonium shots using a one-dimensional geometry. Pulsed power research generally dictates frequent change in hardware configuration. Conversely, SCE applications have typically required constant machine settings. Therefore, while operating during the past four years we have accumulated a large database for evaluation of machine performance under highly consistent operating conditions. Through analysis of this database Cygnus reliability and reproducibility on Armando, Step Wedge, and Thermos is presented.

  19. Soft X-ray spectroscopy of the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    McEntaffer, Randall L.

    My thesis work consisted of the design, fabrication and launch of a sounding rocket payload to observe the spectrum of the soft X-ray emission from the Cygnus Loop supernova remnant. This payload was designated the Cygnus X-ray Emission Spectroscopic Survey (CyXESS) and launched from White Sands Missile Range on November 20th, 2006. The novel X-ray spectrograph incorporated a wire- grid collimator feeding an array of gratings in the extreme off-plane mount which ultimately dispersed the spectrum onto never before flown Gaseous Electron Multiplier (GEM) detectors. This instrument recorded 65 seconds of usable data between 43-49.5 Å in two prominent features. The first feature near 45 Å is dominated by the He-like triplet of O VII in second order with contributions from Mg X and Si IX-Si XII in first order, while the second feature near 47.5 Å is first order S IX and S X. Fits to the spectra give an equilibrium plasma at log( T )=6.2 ( kT e =0.14 keV) and near cosmic abundances. This is consistent with previous observations, which demonstrated that the soft x-ray emission from the Cygnus Loop is dominated by interactions between the initial blast wave with the walls of a precursor formed cavity surrounding the Cygnus Loop.

  20. The Massive Star Forming Region Cygnus OB2

    NASA Astrophysics Data System (ADS)

    Wright, Nicholas James; Drake, J. J.; Drew, J. E.

    2009-12-01

    We present a multi-wavelength study of the massive star forming Cygnus OB2. Cygnus OB2 is the northern hemisphere's most massive star forming region and hosts a tremendously rich and diverse stellar population, with thousands of OB stars. The strong and highly variable extinction in the direction of the association have hindered previous studies of the region, but recent deep photometric surveys in the optical and near-infrared are opening the region up for study. The appreciation of the pivotal status of Cyg OB2 has led to a number of recent ambitious surveys of the cluster and its setting within the Cygnus-X region at X-ray, infrared and radio wavelengths. Chandra X-ray observations of two fields in the center of the association reveal 1720 X-ray sources, which we have combined with optical and near-IR photometry from the IPHAS and UKIDSS surveys. Near-IR photometry reveals a stellar population with a spread of ages greater than previously thought, overturning the picture of coeval star formation in the region. The distribution of young sources in the region shows evidence for clustering and significant mass segregation, which we judge to be primordial given the cluster's age.

  1. 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!

  2. 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)

  3. 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.

  4. CYGNUS X-3's LITTLE FRIEND

    SciTech Connect

    McCollough, M. L.; Smith, R. K.; Valencic, L. A.

    2013-01-01

    Using the unique X-ray imaging capabilities of the Chandra X-ray observatory, a 2006 observation of Cygnus X-3 has provided insight into a singular feature associated with this well-known microquasar. This extended emission, located {approx}16'' from Cygnus X-3, varies in flux and orbital phase (shifted by 0.56 in phase) with Cygnus X-3, acting like a celestial X-ray 'mirror'. The feature's spectrum, flux, and time variations allow us to determine the location, size, density, and mass of the scatterer. We find that the scatterer is a Bok Globule located along our line of sight, and we discuss its relationship to Cygnus X-3. This is the first time such a feature has been identified with Chandra.

  5. Cygnus X-3's Little Friend

    NASA Technical Reports Server (NTRS)

    McCollough, M. L.; Smith, R. K.; Valencic, L. A.

    2010-01-01

    Using the unique X-ray imaging capabilities of the Chandra X-ray observatory, a 2006 observation of Cygnus X-3 has provided insight into a singular feature associated with this well-known microquasar. This extended emission, located approx.16" from Cygnus X-3, varies in flux and orbital phase (shifted by 0.56 in phase) with Cygnus X-3, acting like a celestial X-ray "mirror." The feature s spectrum, flux, and time variations allow us to determine the location, size, density, and mass of the scatterer. We find that the scatterer is a Bok Globule located along our line of sight, and we discuss its relationship to Cygnus X-3. This is the first time such a feature has been identified with Chandra.

  6. Underground muons from Cygnus X-3

    SciTech Connect

    Price, L.E.

    1985-01-01

    Underground detectors, intended for searches for nucleon decay and other rare processes, have recently begun searching for evidence of astrophysical sources, particularly Cygnus X-3, in the cosmic ray muons they record. Some evidence for signals from Cygnus X-3 has been reported. The underground observations are reported here in the context of previous (surface) observations of the source at high energies. 25 refs., 8 figs.

  7. 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

  8. 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.

  9. 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.

  10. 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....

  11. 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.

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

    NASA Astrophysics Data System (ADS)

    McEntaffer, R. L.; Cash, W.

    2008-06-01

    The Cygnus X-Ray Emission Spectroscopic Survey (CyXESS) sounding rocket payload was launched from White Sands Missile Range on 2006 November 20 and obtained a high-resolution spectrum of the Cygnus Loop supernova remnant in the soft X-ray. The novel X-ray spectrograph incorporated a wire-grid collimator feeding an array of gratings in the extreme off-plane mount that ultimately dispersed the spectrum onto gaseous electron multiplier (GEM) detectors. This instrument recorded 65 s of usable data between 43 and 49.5 Å in two prominent features. The first feature near 45 Å is dominated by the He-like triplet of O VII in second order with contributions from Mg X and Si IX-Si XII in first order, while the second feature near 47.5 Å is first-order S IX and S X. Fits to the spectra give an equilibrium plasma at log (T) = 6.2 (kTe = 0.14 keV) and near cosmic abundances. This is consistent with previous observations, which demonstrated that the soft X-ray emission from the Cygnus Loop is dominated by interactions between the initial blast wave and the walls of a precursor-formed cavity surrounding the Cygnus Loop and that this interaction can be described using equilibrium conditions.

  13. 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.

  14. The violent past of Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Kolb, Ulrich; Davies, Melvyn B.; King, Andrew; Ritter, Hans

    2000-09-01

    Cygnus X-2 appears to be the descendant of an intermediate-mass X-ray binary (IMXB). Using Mazzitelli's stellar code we compute detailed evolutionary sequences for the system and find that its prehistory is sensitive to stellar input parameters, in particular the amount of core overshooting during the main-sequence phase. With standard assumptions for convective overshooting a case B mass transfer starting with a 3.5-Msolar donor star is the most likely evolutionary solution for Cygnus X-2. This makes the currently observed state rather short-lived, of order 3Myr, and requires a formation rate > 10-7-10-6yr-1 of such systems in the Galaxy. Our calculations show that neutron star IMXBs with initially more massive donors (>~4Msolar) encounter a delayed dynamical instability; they are unlikely to survive this rapid mass transfer phase. We determine limits for the age and initial parameters of Cygnus X-2 and calculate possible dynamical orbits of the system in a realistic Galactic potential, given its observed radial velocity. We find trajectories which are consistent with a progenitor binary on a circular orbit in the Galactic plane inside the solar circle that received a kick velocity <=200kms-1 at the birth of the neutron star. The simulations suggest that about 7per cent of IMXBs receiving an arbitrary kick velocity from a standard kick velocity spectrum would end up in an orbit similar to Cygnus X-2, while about 10per cent of them reach yet larger Galactocentric distances.

  15. Externally Induced Disks Photoevaporation in the Massive Cluster Cygnus OB2

    NASA Astrophysics Data System (ADS)

    Guarcello, Mario

    2013-07-01

    CygnusOB2, the most massive OB association of the Cygnus-X region, hosts more than 2000 OB stars and a population of young pre-Main Sequence stars. It is 1.4kpc distant from the Sun and the best target to study star formation and disk evolution in the presence of a large number of massive stars. We present a multiwavelength study of protoplanetary disks in Cyg OB2, based on new deep optical and X-ray data obtained with OSIRIS@GTC and Chandra/ACIS-I (the Cygnus OB2 Chandra Legacy Survey), and on archival data from 2MASS, UKIDSS, IPHAS and the Spitzer Legacy Survey of the Cygnus-X Region. We compare the spatial variation of disk fraction with the intensity of the ionized flux emitted by the OB members of CygOB2. We show that the disk fraction decreases gradually with increasing the intensity of the ionizing flux. The results suggests protoplanetary disks in Cyg OB2 suffer long-range photoevaporation induced by the OB star population. This is different than the results obtained in the study of NGC6611 (i.e. Guarcello et al 2007), NGC2264 (i.e. Balog et al. 2007), and the Trapezium in Orion (i.e. Storzer & Hollenbach 1999), where disk fraction drops only in the proximity of the OB stars. We discuss this difference in terms of the larger ionizing flux and older age in Cyg OB2 with respect to these other clusters and touch upon the relevance of this work for planet formation in the universe.

  16. 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.

  17. Shocked clouds in the Cygnus Loop

    NASA Technical Reports Server (NTRS)

    Raymond, John C.

    1994-01-01

    This grant covers the analysis of ROSAT PSPC and HRI images of the Cygnus Loop, an elderly supernova remnant. The project, as proposed, includes not only the usual analysis of ROSAT data; the ROSAT data is being combined with optical and UV data, and new model calculations are being performed. The status is reported on optical imagery, echelle data, IUE data, ROSAT data, and the grain model. The major question being addressed is whether the blastwave-cloud interaction in the feature known as XA is basically a converging shock in a fairly large cloud or turbulent stripping of material from the edges of a smaller cloud.

  18. Shocked clouds in the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    Raymond, John C.

    1994-02-01

    This grant covers the analysis of ROSAT PSPC and HRI images of the Cygnus Loop, an elderly supernova remnant. The project, as proposed, includes not only the usual analysis of ROSAT data; the ROSAT data is being combined with optical and UV data, and new model calculations are being performed. The status is reported on optical imagery, echelle data, IUE data, ROSAT data, and the grain model. The major question being addressed is whether the blastwave-cloud interaction in the feature known as XA is basically a converging shock in a fairly large cloud or turbulent stripping of material from the edges of a smaller cloud.

  19. X-Ray Timing Properties of Cygnus X-1 and Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Focke, Warren Bosworth

    Cygnus X-1 and Cygnus X-2 are X-ray sources which are believed to be a black hole and a neutron star, respectively. 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. The detected shots are fit to several model templates. The fit shot parameters are found to be distributed. The cross spectrum of light curves from Cygnus X-1 in different energy bands is studied. Large, frequency dependent time lags are observed, along with high coherence. The high coherence implies that the transfer function between low and high energy variability is uniform. This implies that, if the lags are due to Compton scattering, variations in the seed intensity must originate in a region much smaller than the Comptonizing medium. The frequency dependence of the lags implies that, if they are due to Comptonization, the Comptonizing medium is nonuniform. The uniformity of the transfer function implies that the observed distribution of shot widths cannot have been acquired through Compton scattering. The energy spectrum of the radiation reaching us from Cygnus X-1 is found to fluctuate at the shortest timescales observable. This implies rapid changes in the geometry or temperature of some portions of the system, possibly due to dynamical instabilities of the system. The high counting rates and temporal resolution of the Rossi X-ray Timing Explorer allow more detailed investigation of the Horizontal Branch Oscillations (HBO) in Cygnus X-2 than has been possible previously, including observation of a second harmonic. The relations of the frequencies and widths of these peaks are investigated in order to shed light on their origin and thus the conditions in the region of their formation. The observations support the Magnetospheric Beat Frequency Modulated Accretion model for the origin of the HBO. The data indicate that neither rapid variation in the frequency of, nor short lifetime of, a locally

  20. MODELING THE INFRARED EMISSION IN CYGNUS A

    SciTech Connect

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

    2012-03-01

    We present new Spitzer IRS spectroscopy of Cygnus A, one of the most luminous radio sources in the local universe. Data on the inner 20'' are combined with new reductions of MIPS and IRAC photometry as well as data from the literature to form a radio through mid-infrared spectral energy distribution (SED). This SED is then modeled as a combination of torus reprocessed active galactic nucleus (AGN) radiation, dust enshrouded starburst, and a synchrotron jet. This combination of physically motivated components successfully reproduces the observed emission over almost 5 dex in frequency. The bolometric AGN luminosity is found to be 10{sup 12} L{sub Sun} (90% of L{sub IR}), with a clumpy AGN-heated dust medium extending to {approx}130 pc from the supermassive black hole. Evidence is seen for a break or cutoff in the core synchrotron emission. The associated population of relativistic electrons could in principle be responsible for some of the observed X-ray emission though the synchrotron self-Compton mechanism. The SED requires a cool dust component, consistent with dust-reprocessed radiation from ongoing star formation. Star formation contributes at least 6 Multiplication-Sign 10{sup 10} L{sub Sun} to the bolometric output of Cygnus A, corresponding to a star formation rate of {approx}10 M{sub Sun} yr{sup -1}.

  1. 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.

  2. Red supergiants and the past of Cygnus OB2

    NASA Astrophysics Data System (ADS)

    Comerón, F.; Djupvik, A. A.; Schneider, N.; Pasquali, A.

    2016-02-01

    Context. Red supergiants are the evolved descendants of massive stars with initial masses between 7 and 40 M⊙. Their brightness makes them easily detectable in the near infrared, making them useful probes of star formation that occurred several tens of Myr ago. Aims: We investigate the past star formation history of Cygnus OB2, the nearest very massive OB association, using red supergiants as a probe. Our aim is to confirm the evidence, found by previous studies, that star formation in the Cygnus OB2 region started long before the latest burst that gave rise to the dense aggregate of early O-type stars that dominate the appearance of the association at present. Methods: Near-infrared star counts in the Cygnus region reveal moderate evidence for a peak in the areal density of bright, reddened stars approximately coincident with Cygnus OB2. A total of 11 sources are found within a circle of 1° radius centered on the association, of which 4 are non-supergiants based on existing observations. Near-infrared spectroscopy is presented of the remaining seven candidates, including four that have been already classified as M supergiants in the literature. Results: We confirm the presence of seven red supergiants in the region and argue that they are probably physically associated with Cygnus OB2. Their location is roughly coincident with that of the older population identified by previous studies, supporting the scenario in which the main star formation activity in the association has been shifting toward higher Galactic longitudes with time. Their luminosities are compared with the predictions of evolutionary tracks with and without rotation to estimate the mass of their progenitors and ages. In this way, we confirm that massive star formation was already taking place in the area of Cygnus OB2 over 20 Myr ago, and we estimate that the star formation rate in the latest 6 Myr represents a six-fold increase over the massive star formation rate at the time when the

  3. 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).

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Forbidden coronal iron emission in the Cygnus Loop

    SciTech Connect

    Teske, R.G. )

    1990-12-01

    Forbidden iron line images of parts of the Cygnus Loop supernova remnant are reported and discussed. Images in both the red and green lines on the rim of NGC 6995 cannot be well interpreted in terms of cloud evaporation, and instead support the reflected shock model of Hester and Cox (1986). On the northeast rim both lines are brightest at the radiative filaments of NGC 6992 and fade to invisibility in the remnant's interior, in agreement with the sheet model for the Cygnus Loop. Forbidden Fe X emission is also found just behind some of the nonradiative filaments lying northeast of the main optical nebulosity, at a location quantitatively consistent with the cosmic-ray shock model of Boulares and Cox (1988). However, the forbidden Fe X and forbidden Fe IV data taken together also qualitatively agree with a hydrodynamic shock and cavity explosion model for the event which created the Cygnus Loop. 20 refs.

  9. 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, M.; 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.

  10. 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.

  11. 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.

  12. Photoevaporating Proplyd-like Objects in Cygnus OB2

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    We report the discovery of 10 proplyd-like objects in the vicinity of the massive OB association Cygnus OB2. They were discovered in IPHAS Hα 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 ~6-14 pc from the OB association, compared to ~0.1 pc for the Orion proplyds, but are clearly being photoionized by the ~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.

  13. 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'.

  14. 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.

  15. 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.

  16. New very massive stars in Cygnus OB2

    NASA Astrophysics Data System (ADS)

    Negueruela, I.; Marco, A.; Herrero, A.; Clark, J. S.

    2008-08-01

    Context: The compact association Cygnus OB2 is known to contain a large population of massive stars, but its total mass is currently a matter of debate. While recent surveys have uncovered large numbers of OB stars in the area around Cyg OB2, detailed study of the optically brightest among them suggests that most are not part of the association. Aims: We observed an additional sample of optically faint OB star candidates, with the aim of checking if more obscured candidates are correspondingly more likely to be members of Cyg OB2. Methods: Low resolution spectra of 9 objects allow the rejection of one foreground star and the selection of four O-type stars, which were later observed at higher resolution. In a subsequent run, we observed three more stars in the classification region and three other stars in the far red. Results: We identify five (perhaps six) new evolved very massive stars and three main sequence O-type stars, all of which are likely to be members of Cyg OB2. The new findings allow a much better definition of the upper HR diagram, suggesting an age ~2.5 Myr for the association and hinting that the O3-5 supergiants in the association are blue stragglers, either younger or following a different evolutionary path from other cluster members. Though the bulk of the early stars seems to belong to an (approximately) single-age population, there is ample evidence for the presence of somewhat older stars at the same distance. Conclusions: Our results suggest that, even though Cyg OB2 is unlikely to contain as many as 100 O-type stars, it is indeed substantially more massive than was thought prior to recent infrared surveys. Figure [see full textsee full textsee full textsee full textsee full textsee full textsee full text] and Table [see full textsee full textsee full textsee full textsee full textsee full textsee full text] are only available in electronic form at http://www.aanda.org

  17. 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.

  18. NuSTAR Observations of V404 Cygnus in Outburst

    NASA Astrophysics Data System (ADS)

    Walton, Dom; NuSTAR Collaboration

    2016-04-01

    The Galactic LMXB V404 Cygnus, one of the closest known black hole binary systems, went through its first major outburst in ~25 years in summer 2015. Over the course of this event, the NuSTAR observatory played an active role in the substantial multi-wavelength campaign initiated, performing a series of exposures covering a span of several weeks. These observations revealed extreme variability on both long and short timescales, as well as complex broadband X-ray spectra. More recently, after having returned to quiescence, V404 Cygnus also exhibited an unexpected re-brightening only ~6 months later. In this talk I will present an overview of the NuSTAR campaign, and discuss some early results from these observations.

  19. The X-ray halo of Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Bode, M. F.; Norwell, G. A.; Priedhorsky, W. C.; Evans, A.

    1985-01-01

    Four Einstein HRI images of Cygnus X-1 were examined for the presence of a halo due to scattering of X-rays by interstellar grains. The analysis technique exploits the intrinsic aperiodic variability of the source to map the point response function of the optics. A residual, nonvariable component to the surface brightness distribution (comprising approximately more than 12 percent of the source flux) is interpreted as a scattered halo. The halo flux does not reflect the short term time variability of the central source as it is smoothed by differential time delays of order days. The Cygnus X-1 halo is consistent with those of other sources derived in previous studies using different techniques. Comparison is made with a scattering model, and the sensitivity of the halo flux to maximal grain size is demonstrated.

  20. Cygnus OB2: Star Formation Ugly Duckling Causes a Flap

    NASA Astrophysics Data System (ADS)

    Drake, Jeremy J.; Wright, Nicholas; Guarcello, Mario

    2015-08-01

    Cygnus OB2 is one of the largest known OB associations in our Galaxy, with a total stellar mass of 30,000 Msun and boasting an estimated 65 O-type stars and hundreds of OB stars. At a distance of only 1.4kpc, it is also the closest truly massive star forming region and provides a valuable testbed for star and planet formation theory. We have performed a deep stellar census using observations from X-ray to infrared, which has enabled studies of sub-structuring, mass segregation and dynamics, while infrared data reveal a story of protoplanetary disk attrition in an extremely harsh radiation environment. I will discuss how Cygnus OB2 challenges the idea that stars must form in dense, compact clusters, and demonstrates that stars as massive as 100 Msun can form in relatively low-density environments. Convincing evidence of disk photoevaporation poses a potential problem for planet formation and growth in starburst environments.

  1. 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).

  2. Evidence for observation of underground muons from Cygnus X-3

    SciTech Connect

    Bartelt, J.; Courant, H.; Heller, K.; Heppelmann, S.; Joyce, T.; Peterson, E.A.; Marshak, M.L.; Ruddick, K.; Shupe, M.; Ayres, D.S.

    1985-01-01

    We have observed evidence for an average underground muon flux of approx. = 7 x 10/sup -11/ cm/sup -2/ s/sup -1/ 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. These observations cannot be explained by conventional models of the propagation and interaction of cosmic rays. 13 refs., 2 figs.

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

    SciTech Connect

    Johns, K.; Marshak, M.L.; Peterson, E.A.; Ruddick, K.; Shupe, M. . School of Physics and Astronomy); Ayres, D.S.; Fields, T.H.; May, E.N.; Price, L.E. )

    1989-09-11

    We report on 3.2 years live time of underground muon observations taken between 1981 and 1989 using the Soudan 1 proportional tube detector, located at a depth of 1800 m water equivalent. The post-1984 observations are consistent with our earlier data on an excess signal apparently correlated with the Cygnus X-3 orbital period. The signal-to-background ratio in the entire data sample is 1 to 3 percent, depending on phase width. 10 refs., 2 figs., 1 tab.

  4. 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

  5. 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

  6. 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

  7. Soft X-ray search of centre of Cygnus Loop

    NASA Technical Reports Server (NTRS)

    Snyder, W. A.; Henry, R. C.; Charles, P. A.; Culhane, J. L.; Sanford, P. W.; Bleach, R.; Drake, J.

    1975-01-01

    Equipment on the Copernicus satellite has been used to search for evidence of a compact object in the center of the Cygnus Loop supernova remnant. Rocket measurements reported by Rappaport et al. (1973) indicate that a central object exists. However, the study conducted with the aid of the satellite was negative. This negative result could indicate that the X-ray source was simply not in its high-intensity mode at the time of observation, or could arise because the source is at some other location in the Loop.

  8. 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.

  9. The Variable Superorbital Modulation of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Rico, Javier

    2008-08-01

    We study the superorbital modulation present in the Cygnus X-1 X-ray data, usually attributed to the precession of the accretion disk and relativistic jets. We find a new, strong, 326 ± 2 day period modulation starting in 2005, in Swift BAT and RXTE ASM light curves (LCs). We also investigate Vela 5B ASM and Ariel 5 ASM archival data and confirm the previously reported ~290 day periodic modulation, therefore confirming that the superorbital period is not constant. Finally, we study RXTE ASM LC before 2005 and find that the previously reported ~150 day period is most likely an artifact due to the use of a Fourier-power-based analysis under the assumption that the modulation has a constant period along the whole data sample. Instead, we find strong indications of several discrete changes of the precession period, happening in coincidence with soft and failed state transition episodes. We also find a hint of correlation between the period and the amplitude of the modulation. The detection of gamma rays above 100 GeV with MAGIC in 2006 September happened in coincidence with a maximum of the superorbital modulation. The next maximum will happen between 2008 July 2 and 14, when the observational conditions of Cygnus X-1 with ground-based Cerenkov telescopes, such as MAGIC and VERITAS, are optimal.

  10. 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.

  11. RXTE observation of Cygnus X-1: spectral analysis

    NASA Astrophysics Data System (ADS)

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

    1999-01-01

    We present the results of the analysis of the broad-band spectrum of Cygnus X-1 from 3.0 to 200keV, using data from a 10ksec 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 Γ=1.45+0.01-0.02, e-folding energy Ef=162+9-8keV, plus a deviation from a power law that formally can be modeled as a thermal blackbody with temperature kTBB=1.2+0.0-0.1keV), the inclusion of a reflection component does not improve the fit. As a physical description of this system, we apply the accretion disc corona (ADC0 models of Dove, Wilms & Begelman [1]). A slab-geometry ADC model is unable to describe the data. However, a spherical corona, with a total optical depth τ=1.6+/-0.1 and an average temperature kTC=87+/-5keV, surrounded by an exterior cold disc, does provide a good description of the data (χ2red=1.55). These models deviate from the data by up to 7% in the 5-10keV range. However, considering how successfully the spherical corona reproduces the 10-200keV data, such ``photon-starved'' coronal geometries seem very promising for explaining the accretion processes of Cygnus X-1.

  12. 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.

  13. A Cornucopia of Massive Binary Star Systems in the Cygnus OB2 Association: Fifty and Counting

    NASA Astrophysics Data System (ADS)

    Kobulnicky, Henry A.; Kiminki, D. C.; Burke, J. F.; Chapman, J. E.; Keller, E.; Lester, K. V.; Rolen, E.; Topel, E.; Lundquist, M. J.; Bhattacharjee, A.; Vargas Alvarez, C. A.; Runnoe, J. C.; Dale, D. A.

    2014-01-01

    Massive binary star systems produce nature's most energetic events, including some classes of supernovae, gamma-ray bursts, X-ray binaries, and double-degenerate objects that generate gravitational wave radiation. The Cygnus OB2 Association is the largest nearby collection of massive stars, consisting of several hundred O and early B stars at a distance of just 1.4 kpc. Our Cygnus OB2 Radial Velocity Survey team at the University of Wyoming has spectroscopically monitored 115 stars of type B2 or earlier between 1999 and 2013, accruing an average of 12 observations per star at a velocity precision of 2-6 km/s. We have identified fifty massive binary systems, nearly all of which have full orbital solutions. Periods range from 1.4 days - 12.5 years and velocity semi-amplitudes span 4-300 km/s. Monte-Carlo modeling indicates that as many as 90% of massive systems contain multiple stars and that 45% of these can be characterized as ``close'' binaries that will interact, exchanging matter during main-sequence or post-main-sequence evolution. Statistical analysis of the orbital parameters reveals a striking surplus of close, short-period systems with periods P=1.4--7 days, with fully 30% (17 out of 50 systems) of the known binaries falling in this tight range; their typical orbital separations are just a small fraction of an astronomical unit. The remainder of the binary systems are consistent with a period distribution described as flat in log(P) out to several thousand day periods. The mass ratio distribution appears flat over the interval q=M2/M1=0.1-1.0, meaning that massive stars preferentially have massive companions. These data constitute the largest and most complete homogeneous database on any single collection of massive stars in a common formation environment covering the full range of stars expected to explode as supernovae (B2V and earlier). As such, the Survey provides the raw data for modeling rates of cosmic supernova, gamma-ray bursts, and X-ray binaries

  14. A continuous watch of the northern sky above 40 TeV with the CYGNUS array

    SciTech Connect

    Haines, T.J.; Miller, R.; Sinnis, C.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The aim of the project has been to continuously monitor the northern sky for transient high-energy gamma-ray emission from astrophysical sources. Potential objects of such emission include gamma-ray bursts and flares from active galaxies. At the start of this project, the CYGNUS extensive air shower array was used for the monitoring; CYGNUS has an energy threshold of {approximately}40 TeV. In August, 1996, the CYGNUS data-acquisition computer suffered a fatal hardware problem so data-taking with the array ended. The Milagrito detector, which is much more sensitive than CYGNUS, started taking data in February 1997 and has continued the sky monitoring. The authors are presently honing reconstruction algorithms for Milagrito. When this is complete, the data taken since February will be analyzed for transient emission.

  15. Nature of the high-energy particles from Cygnus X-3

    SciTech Connect

    Dar, A.; Lord, J.J.; Wilkes, R.J.

    1986-01-01

    If the published experimental results on both air showers and underground muons generated by particles from Cygnus X-3 are correct, then these particles cannot be any presently known elementary particles, neutral atoms, or micrograins of ordinary matter. The primary particles from Cygnus X-3 must be electrically neutral, relatively stable, strongly or electromagnetically interacting, and have rest mass less than 50 MeV/cS.

  16. Astronomy at ultra-high energies: Results from the CYGNUS experiment

    SciTech Connect

    Alexandreas, D.E.; Allen, R.C.; Biller, S.D.; Dion, G.M.; Lu, X-Q.; Vishwanath, P.R.; Yodh, G.B. ); Berley, D.; Chang, C.Y.; Dingus, B.L.; Goodman, J.A.; Haines, T.J.; Kwok, P.; Stark, M.J.; Talaga, R.L. ); Burman, R.L.; Hoffman, C.M.; Lloyd-Evans, J.; Nagle, D.E.; Potter, M.E.; Sandberg, V.D.; Zhang, W. ); C

    1990-01-01

    The CYGNUS experiment is composed of an air-shower array and muon detectors, located in Los Alamos, NM, and operating at energies above 50 TeV. Recent results include a search for emission from Cygnus X-3 during the radio outbursts of June and July 1989, preliminary results from a search for diffuse emission from the galactic plane, and preliminary results from a search for emission from possible northern hemisphere point sources, both known and unknown. 3 refs., 4 figs.

  17. 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.

  18. X-ray spectrum of the entire Cygnus Loop.

    NASA Technical Reports Server (NTRS)

    Stevens, J. C.; Riegler, G. R.; Garmire, G. P.

    1973-01-01

    The spectrum of the entire Cygnus Loop has been obtained using gas-filled proportional counters and filters flown on a Nike-Aerobee rocket. The results indicate an average spectral temperature of (2.8 plus or minus 0.2) x 1,000,000 K and the presence of excess emission in the energy range from 0.530 to 0.693 keV. If the excess emission originates in a single line at 0.658 keV, the intensity at the earth corresponds to 1.8 plus or minus 0.7 photons per sq cm per sec, or about 10% of the total energy received from the Loop. The spectrum of the entire Loop is found to be attenuated by an average of (4.8 plus or minus 0.2) x 10 to the 20th hydrogen atoms per sq cm.

  19. 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.

  20. 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.

  1. Gamma-ray observations of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Bassani, L.; Di Cocco, G.; Stephen, J. B.; Dean, A. J.; Perotti, F.

    1989-08-01

    The results of gamma-ray observations of the Galactic black hole candidate Cygnus X-1 are presented. The recent HEAO 3 results reported by Ling et al. (1987) on this source are confirmed: (1) the detection in 1979 of a gamma-ray excess of comparable flux; and (2) a spectral variation above about 25 keV going from 1979 to 1980, which implies and anticorrelation between hard X-ray and gamma-ray luminosities with a pivot point in the 200-400 keV band. A comparison of all the data available at gamma-ray energies gives further support to the existence of this anticorrelation, although its statistical significance is low. The hard X-ray/gamma-ray 1979 spectrum, which is well fitted by a power law with photon index alpha = 1.7, can be interpreted as thermal Comptonization of soft photons or in terms of nonthermal models with copious photon-photon absorption.

  2. Complete mitochondrial genome of Cygnus olor (Aves, Anseriformes, Anatidae).

    PubMed

    Park, Chang Eon; Park, Gun-Seok; Kwak, Yunyoung; Hong, Sung-Jun; Khan, Abdur Rahim; Jung, Byung Kwon; Park, Yeong-Jun; Kim, Jong-Guk; Park, Hee Cheon; Shin, Jae-Ho

    2016-09-01

    The complete mitochondrial genome of Cygnus olor (Aves, Anseriformes, Anatidae) was revealed in this study. Total 16 739 base pairs (bp) of this mitogenome encoded genes for 13 protein coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs) and a D-loop (control region). The 12S rRNA and 16S rRNA genes are located between tRNA-Phe and tRNA-Leu (UUR) and segmentalized by the tRNA-Val. D-loop is located between tRNA-Glu and tRNA-Phe. The overall base composition of C. olor is G + C: 47.8%, A + T: 52.2%, apparently with a slight AT bias. Following the phylogenetic analysis, the C. olor was closed to Anser cygnoides. PMID:26153738

  3. 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.

  4. 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.

  5. 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.

  6. RXTE observation of Cygnus X-1 - I. Spectral analysis

    NASA Astrophysics Data System (ADS)

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

    1998-08-01

    We present the results of the analysis of the broad-band spectrum of Cygnus X-1 from 3.0 to 200keV, using data from a 10-ks observation by the Rossi X-ray Timing Explorer (RXTE). The spectrum can be well described phenomenologically by an exponentially cut-off power law with a photon index Γ=1.45+0.01-0.02 (a value considerably harder than is typically found), e-folding energy Ef=162+9-8keV, plus a deviation from a power law that formally can be modelled as a thermal blackbody with temperature kTbb=1.2+0.0-0.1keV. Although the 3-30 keV portion of the spectrum can be fitted with a reflected power law with Γ=1.81+/-0.01 and covering fraction f=0.35+/-0.02, the quality of the fit is significantly reduced when the HEXTE data in the 30-100 keV range are included, as there is no observed softening 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 &38 Begelman, in which the temperature of the corona is determined self-consistently. A spherical corona with a total optical depth τ=1.6+/-0.1 and an average temperature kTc=87+/-5keV, surrounded by an exterior cold disc, does provide a good description of the data (χ2red=1.55). These models deviate from the data by up to 7 per cent in the 5-10keV range, and we discuss possible reasons for these discrepancies. However, considering how successfully the spherical corona reproduces the 10-200keV data, such `photon-starved' coronal geometries seem very promising for explaining the accretion processes of Cygnus X-1.

  7. 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.

  8. 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).

  9. 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.

  10. New measurements of the 12. 6 millisecond pulsar in Cygnus X-3

    SciTech Connect

    Brazier, K.T.S.; Carraminana, A.; Chadwick, P.M.; Dipper, N.A.; Lincoln, E.W. )

    1990-02-01

    Evidence for a 12.59 ms pulsar in Cygnus X-3 is presented on the basis of TeV gamma-ray observations. Evidence for pulsed emission at a phase in the 4.8 hr cycle and with a pulsar period and secular period derivative are compatible with earlier measurements (Chadwick et al., 1985). The conservative overall Rayleigh probability of uniformity of phase for this new result is 1.7 x 10 to the -6th. Data from observations of Cygnus X-3 from 1981 to 1985 are analyzed using a new X-ray ephemeris of the 4.8 hr X-ray cycle. This suggests that Cygnus X-3 is producing sporadic very high energy gamma rays at a fixed time in the 4.8 hr X-ray cycle. 28 refs.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. Discovery of dense absorbing clouds in Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Balucinska-Church, Monika; Schulz, Norbert S.; Church, Michael; Wilms, Joern; Hanke, Manfred

    We report results of several day-long observation of Cygnus X-2 using Chandra and XMM-Newton. The source displayed extensive dipping events in the lightcurve often seen before in the source and causing an additional track in the hardness-intensity Z-track diagram. For the first time we are able to investigate these events using both high efficiency CCD continuum spectra and highly-resolved grating data. In the XMM PN instrument, the dips are 30% deep and resemble those in the low mass X-ray binary dip sources. However, remarkably, in the Chandra HEG and MEG no absorption or edge features can be seen corresponding to expected increases of column density in excess of the interstellar column. Non-dip and dip PN spectra are fitted well with a model containing point-like blackbody emission which we associate with the neutron star plus Comptonized emission of the ADC which must be extended. Dipping can be explained without absorption of the blackbody emission, but by covering 40% of the extended ADC emission by dense absorber. In the covered fraction almost no flux remains and so no significant additional optical depths appear in the neutral K edges in the grating spectra. The dipping appears not to be explicable by absorption in the outer disk, but requires large, dense blobs of absorber that do not overlap the neutron star in the line-of-sight. The nature of these blobs is unknown.

  16. 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.

  17. 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

  18. 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.

  19. 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.

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

    SciTech Connect

    Ayres, D.S.

    1985-09-01

    The Soudan 1 experiment has yielded evidence for an average underground muon flux of approx.7 x 10/sup -11/ cm/sup -2/ s/sup -1/ 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 conventional models of the propagation and interaction of cosmic rays. 16 refs., 5 figs., 1 tab.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Isolation and genetic characterization of Toxoplasma gondii from mute swan (Cygnus olor) from the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study, antibodies to T. gondii were determined in serum samples from 632 mute swans (Cygnus olor) collected from different areas of the USA. Sera were tested by T. gondii modified agglutination te...

  10. Application of cosmic-ray shock theories to the Cygnus Loop - an alternative model

    NASA Astrophysics Data System (ADS)

    Boulares, Ahmed; Cox, Donald P.

    1988-10-01

    Steady state cosmic-ray shock models are investigated in light of observations of the Cygnus Loop supernova remnant. In this work the authors find that the model of Völk, Drury, and McKenzie, 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 Cygnus Loop shocks. The waves heat the gas substantially in the cosmic-ray precursor, in addition to the usual heating in the (possibly weak) gas shock. The model is used to deduce upstream densities and shock velocities using known quantities for Cygnus Loop shocks. Compared to the usual pure gas shock interpretation, it is found that lower densities and approximately 3 times higher velocities are required. If the cosmic-ray models are valid, this could significantly alter our understanding of the Cygnus Loop's distance and age and of the energy released during the initial explosion.

  11. Fermi-LAT Observation of Increased Gamma-ray Emission from the Microquasar Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Loh, Alan; Corbel, Stephane; Dubus, Guillaume; Corbet, Robin

    2016-01-01

    Recently, the hard X-ray emission from the high-mass X-ray binary Cygnus X-3 has drastically dropped since 2016 Jan 11 (MJD 57398, as observed by Swift/BAT http://swift.gsfc.nasa.gov/results/transients/CygX-3/, Krimm et al. 2013, ApJS 209, 14) indicating a possible transition to the soft state.

  12. 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.

  13. 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.

  14. 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 year baseline and have typical precisions < 1 mas/yr. We calculate the velocity dispersion in the two axes to be $\\sigma_\\alpha(c) = 13.0^{+0.8}_{-0.7}$ and $\\sigma_\\delta(c) = 9.1^{+0.5}_{-0.5}$ km/s, using a 2-component, 2-dimensional model that takes into account the uncertainties on the measurements. This gives a 3-dimensional velocity dispersion of $\\sigma_{3D} = 17.8 \\pm 0.6$ km/s 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$_\\odot$, 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.

  15. 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 ...

  16. 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

  17. 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).

  18. The nature of the hard state of Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Hjalmarsdotter, L.; Zdziarski, A. A.; Larsson, S.; Beckmann, V.; McCollough, M.; Hannikainen, D. C.; Vilhu, O.

    2008-02-01

    The X-ray binary Cygnus X-3 (Cyg X-3) is a highly variable X-ray source that displays a wide range of observed spectral states. One of the main states is significantly harder than the others, peaking at ~20 keV, with only a weak low-energy component. Due to the enigmatic nature of this object, hidden inside the strong stellar wind of its Wolf-Rayet companion, it has remained unclear whether this state represents an intrinsic hard state, with truncation of the inner disc, or whether it is just a result of increased local absorption. We study the X-ray light curves from RXTE/ASM and CGRO/BATSE in terms of distributions and correlations of flux and hardness and find several signs of a bimodal behaviour of the accretion flow that are not likely to be the result of increased absorption in a surrounding medium. Using INTEGRAL observations, we model the broad-band spectrum of Cyg X-3 in its apparent hard state. We find that it can be well described by a model of a hard state with a truncated disc, despite the low cut-off energy, provided the accreted power is supplied to the electrons in the inner flow in the form of acceleration rather than thermal heating, resulting in a hybrid electron distribution and a spectrum with a significant contribution from non-thermal Comptonization, usually observed only in soft states. The high luminosity of this non-thermal hard state implies that either the transition takes place at significantly higher L/LE than in the usual advection models, or the mass of the compact object is >~20Msolar, possibly making it the most-massive black hole observed in an X-ray binary in our Galaxy so far. We find that an absorption model as well as a model of almost pure Compton reflection also fit the data well, but both have difficulties explaining other results, in particular the radio/X-ray correlation.

  19. 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.

  20. 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

  1. 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

  2. Observations of ultra-high-energy photons from Cygnus X-3

    SciTech Connect

    Muraki, Y.; Shibata, S.; Aoki, T.; Mitsui, K.; Okada, A. Tokyo, University )

    1991-06-01

    Extensive air showers coming from the Cygnus X-3 region are analyzed using the van der Klis and Bonnet-Bidaud ephemeris. A 4.7 sigma excess has been observed in the phase bin 0.25-0.3. The maximum excess is seen when a muon cut is applied to the showers, which indicates a slightly muon poor property. The flux is estimated to be (2.7 + or {minus} 0.5) {times} 10 to the -14th/sq cm s for the showers Ne greater than 200,000. DC excesses are observed at the time of the radio burst of Cygnus X-3 in June 1989. 21 refs.

  3. 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.

  4. 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.

  5. 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.

  6. Lepto-hadronic model for the broadband emission of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Pepe, Carolina; Vila, Gabriela S.; Romero, Gustavo E.

    2015-12-01

    Context. Cygnus X-1 is a well-observed microquasar. Broadband observations at all wavelengths have been collected over the years. The origin of the MeV tail observed with COMPTEL and INTEGRAL is still under debate and it has mostly been attributed to the corona, although its high degree of polarization suggests that it is synchrotron radiation from a jet. The origin of the transient emission above ~100 GeV is also unclear. Aims: We aim to clarify the origin of the broadband spectral energy distribution (SED) of Cygnus X-1, focusing particularly on the gamma-ray emission, and to gain information on the physical conditions inside the jets. Methods: We developed a lepto-hadronic, inhomogeneous jet model and applied it to the non-thermal SED of Cygnus X-1. We calculated the contributions to the SED of both protons and electrons accelerated in an extended region of the jet. We also estimated the radiation of charged secondaries produced in hadronic interactions through several radiative processes. Absorption effects were considered. We produced synthetic maps of the jets at radio wavelengths. Results: We find two sets of model parameters that lead to good fits of the SED. One of the models fits all the observations, including the MeV tail. This model also predicts hadronic gamma-ray emission slightly below the current upper limits. The flux predicted at 8.4 GHz is in agreement with the observations available in the literature, although the synthetic source is more compact than the imaged radio jet. Conclusions: Our results show that the MeV emission in Cygnus X-1 may be jet synchrotron radiation. This depends mainly on the strength of the jet magnetic field and the location of the injection region of the relativistic particles. Our calculations show that there must be energetic electrons in the jets quite far from the black hole.

  7. Fussy feeders: phyllosoma larvae of the Western Rocklobster (Panulirus cygnus) demonstrate prey preference.

    PubMed

    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

  8. Predicting GAIA's Parallax Distance to the Cygnus OB2 Association with Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Kiminki, Daniel C.; Kobulnicky, Henry A.; Vargas Álvarez, Carlos A.; 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.

  9. W 58 G - A distant H II region in the H I Cygnus arm

    NASA Astrophysics Data System (ADS)

    Georgelin, Y. M.; Boulesteix, J.; Georgelin, Y. P.; Le Coarer, E.; Marcelin, M.; Monnet, G.

    1988-01-01

    A 9arcmin×9arcmin sky area centered on the galactic nebula W58 G has been scanned at Hα wavelength with the CIGALE instrument at the prime focus of the 2.6 m Armenian telescope in Byurakan. Four distinct nebular emissions can be distinguished along the same line of sight. Two are related to the nearby Cygnus complex, one at VLSR = 9 km s-1 is associated with the Cygnus Rift at 900 pc and another one at VLSR = 60 km s-1 is probably due to stellar winds or supernova remnants. The third emission, at VLSR = -26 km s-1, is the optical counterpart of the Extended Region South East of W58, mapped by Israel (1976) in the radio continuum, in the Perseus arm (8.4 kpc). The fourth emission comes from W58 G, an H II region which appears to belong to the H I Cygnus arm, with VLSR = -66 km s-1, at a distance of 12.4 kpc.

  10. The physics and validation of the Cygnus radiographic source for Armando

    NASA Astrophysics Data System (ADS)

    Berninger, M.; Lutz, S.; Devolder, B.; Yin, L.; Kwan, T.

    2003-10-01

    Conventional simulation techniques for radiographic systems use approximations that poorly represent the dynamics of the electron beam that generates photons via the bremsstrahlung process. The radiographic chain model more accurately accounts for the electron dynamics by linking electron distributions generated in electromagnetic particle-in-cell (PIC) simulations in a self-consistent way to the Monte Carlo particle transport code MCNP. Based on the electron dynamics from PIC simulations, MCNP simulates the emission of bremsstrahlung photons due to the electron collisions with a dense target in the radiographic source and then calculates the photon transport through the imaging object onto the detectors, which are simulated with detector response functions. This integrated radiographic simulation capability has been applied in understanding the Cygnus source physics. By employing the methodology of the chain model, we characterized the effect of the rod-pinch diode operating parameters on the Cygnus radiographic machine parameters, such as energy- and angle-dependent photon spectra, spot size, and dose. The calculations were validated in juxtaposition with radiographic experimental data on step wedges, rolled edges, and static objects. We present the detailed characterization of the performance of the Cygnus source for Armando.

  11. 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.

  12. Carbon, Helium, and Proton Kinetic Temperatures in a Cygnus Loop Shock Wave

    NASA Astrophysics Data System (ADS)

    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-1shock 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-1shock 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.

  13. 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.

  14. Dying Pulse Trains in Cygnus XR-1: Initial Results of X-Ray Searches

    NASA Technical Reports Server (NTRS)

    Dolan, Joseph F.

    2003-01-01

    Dying pulse trains (DPT's) are a signature of a black hole as described by general relativity. Detecting DPT's would establish the existence of black holes by ruling out more exotic objects in systems in which a neutron star or white dwarf component has already been excluded by maximum mass arguments. The positive identification of a black hole would also be an additional test of general relativity. Two possible DPT's were detected in W photometry of Cygnus XR-1, the leading candidate for a stellar mass sized BH, in 3 hours of observational data. A search of X-ray photometry of Cygnus XR-1 from the Ross1 X-ray Timing Explorer (RXTE) has begun. No DPT's have been detected in the first 4 hours of data searched. Because of the low event rate detected in the W data, these initial results are consistent with such disparate scenarios as the rate of DPT occurrence being dependent on the luminosity state of the system; or being more difficult to detect in the X-ray region relative to the W region; or occurring at the same rate in the W and X-ray regions; or even not occurring at all from Cygnus XR-1. The search for DPT's in RXTE photometry is continuing.

  15. Soft X-ray Excesses and X-ray Line Variability in Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Varlotta, Angelo; McCollough, Michael L

    2014-06-01

    Cygnus X-3 is an X-ray binary (XRB) system containing a stellar-mass compact object, most likely a black hole, and a Wolf-Rayet companion star, which produces collimated, relativistic jets, placing it in the sub-class of XRBs known as microquasars. During a Swift/XRT monitoring program of Cygnus X-3, a soft X-ray excess (below 1 keV) was observed at certain states and phases of activity. This soft excess appears to be similar to the variable soft emission observed in Seyfert galaxies. The presence of these features in Cygnus X-3 would argue for a greater support of the black-hole nature of the compact object and serve to better highlight the similarities of microquasars and AGN. We present the results of our investigations of these soft excesses, as well as the variations of the X-ray Fe line region (6.4-7.0 keV) as a function of the state activity and orbital phase.

  16. Investigation of TeV Gamma-Ray Emission from Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Georgievna Sinitsyna, V.; Arsov, T.P.; Alaverdian, A.Y.; Borisov, S.S.; Musin, F.I.; Mirzafatikhov, R.M.; Nikolsky, S.I.; Kasparov, G.M.; Sinitsyna, V.Y.; Platonov, G.F.

    2003-07-01

    Cherenkov mirror telescope SHALON-1 created at Leb edev Physical Institute and stated at 1991-1992 y. at Tien-Shan mountains 3338 m high above the sea level with 11,2 m2 mirror area and image matrix consisting of 144 photomultipliers with total viewing angle of 8o during 1992-2003 y. was used for observations of galactic sources: Crab Nebula, Cygnus X-3 Ticho Brage, Geminga and metagalactic sources: Markarian 421, Markarian 501, NGC 1275, 3C454.3, 1739+522. Timing analysis show that the contribution of protons of cosmic rays in observable gamma-quanta with energy more than 0.8TeV from the point sources of gammaquanta very high energies do not exceed 10% 15%. The fluxes at energy above 0.8TeV of observation Cygnus X-3 (4.20 ± 0.70) • 10-13 cm-2 s-1 is and Crab Nebula (1.10 ± 0.13) • 10-12 cm-2 s-1 . The observable energy distribution of gamma quanta in an interval of energy 1012 - 5 • 1013 from the local sources in our Galaxy do not contradict with the spectrum of Cygnus X-3 dF /dEγ ˜ Eγ 2.20±0.14 ,- of Crab Nebula -dF /dEγ ˜ Eγ 2.45±0.04 . The observed spectra of the gamma- quanta including the 10%-15% contribution of the proton showers is for Cygnus dF /dE ˜ E -2.51±0.22 , for Crab Nebula dF /dE ˜ E -2.61±0.04 . The images of Cygnus X-3 and Crab Nebula are also presented. One of the basic science parts is nuclear physics, physics of elementary particles and connected with them astrophysics and cosmology, studied the matter structure on micro and macro scales. The gamma-astronomy is a unique experimental possibility of high-energy cosmic rays sources (1012 - 1014 eV) location now. Only neutrino-astronomy will complete search and investigation of galactic and metagalactic objects where the protons and nuclei acceleration processes, accompanying with generation of non scattering by Universal magnetic fields gammas and neutrinos. The cosmological processes, connecting the physic of matter structure with its superdense quasistable state in active

  17. 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.

  18. 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.

  19. 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

  20. The nature of the Cygnus X-2 like Low Mass X-ray Binaries

    NASA Astrophysics Data System (ADS)

    Gibiec, Andrzej; Balucinska-Church, Monika; Church, Michael

    We propose a physical model of the Cygnus X-2 like Z-track sources: GX 340+0, GX 5-1 and Cygnus X-2 based on the results of applying a particular emission model for low mass X-ray binaries to high quality Rossi-XTE data on the sources. In this emission model the Comptonizing Accretion Disk Corona is very extended, and the evidence for this is now very secure. In our physical model, the Normal Branch is dominated by an increasing mass accretion rate between the soft and hard apex leading to a much increased neutron star temperature resulting in high radiation pressure of the neutron star. The radiation pressure continues to increase on the Horizontal Branch becoming several times super-Eddington. We propose that this disrupts the inner accretion disk and that part of the accretion flow is diverted vertically forming jets which are detected by their radio emission on this part of the Z-track. We thus propose that high radiation pressure is the main factor responsible for the launching of jets. On the Flaring Branch there is a large increase in the neutron star blackbody luminosity at constant mass accretion rate showing that there is an additional energy source on the neutron star. We find good agreement between the mass accretion rate per unit emitting area of the neutron star at the onset of flaring and the theoretical critical value at which burning becomes unstable and propose that flaring in the Cygnus X-2 like sources consists of unstable nuclear burning. Correlation of kilohertz QPO frequencies in all three sources with spectral fitting results leads to the proposal that the upper kHz QPO always takes place at the inner accretion disk edge, the radius of which increases due to disruption of the disk by the high radiation pressure.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. On the distance to Cygnus X-1. [extrapolation from nearby stars

    NASA Technical Reports Server (NTRS)

    Margon, B.; Bowyer, S.; Stone, R. P. S.

    1973-01-01

    Interstellar extinction of 50 stars in the immediate vicinity of Cyg X-1 is compared with color excess of HDE 226868. The fact that HDE 226868 has extinction drastically exceeding that of all stars in the field at less than 1 kpc is believed to be in conflict with the model of Trimble et al. (1973) in which the primary is a luminous undermassive star and with other similar models. Uniform extrapolation of the reddening yields a distance estimate of (2.5 plus or minus 0.4) kpc for Cygnus X-1, in agreement with the spectroscopic modulus for an O9 star.

  8. X-ray astronomy. [Crab Nebula, Cygnus Loop and the Perseus Cluster

    NASA Technical Reports Server (NTRS)

    Novick, R.

    1975-01-01

    Various experiments in X-ray astronomy are described. The occurrence of lunar occultations of the Crab Nebula were utilized to determine the spatial distribution of X-ray emitting regions in the nebula. Study of the Cygnus Loop included a search for a central X-ray point source for the area and measurement of the energy spectrum of the flux from the supernova remnant. The X-ray morphology of the Perseus cluster of galaxies was studied. X-ray spectra of different points in the cluster were also obtained. In addition, the construction of a high resolution gas fluorescence proportional counter for application to X-ray astronomy is discussed.

  9. 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}.

  10. 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].

  11. SMM/HXRBS observations of Cygnus X-1 from 1986 December to 1988 April

    NASA Astrophysics Data System (ADS)

    Schwartz, R. A.; Orwig, L. E.; Dennis, B. R.; Ling, J. C.; Wheaton, W. A.

    1991-07-01

    The Solar Maximum Mission's Hard X-ray Burst Spectrometer made 30 measurements of Cygnus X-1 from December, 1986 to April, 1988, yielding a data set of broad synoptic coverage but limited duration for each data point. The hard X-ray intensity was found to be between the gamma(2) and gamma(3) levels, with a range of fluctuations about the average intensity level. The shape of the photon spectrum was found to be closest to that reported by Ling et al. (1983, 1987) during the time of the gamma(3) level emission, although the spectral shapes reported for the gamma(2) and gamma(1) levels were not precluded.

  12. An Investigation into PAH Destruction in Nearby Supernova Remnants, North Polar Spur and Cygnus Loop

    NASA Astrophysics Data System (ADS)

    Burkhart, Sarah M.; Witt, Adolf N.

    2015-01-01

    Our goal in conducting this research was to look at the polycyclic aromatic hydrocarbon (PAH)/large dust grain emission intensity ratio in nearby supernova remnants to find evidence for selective PAH destruction by hot gas and high velocity shock waves within these regions, as predicted by the models of Arendt et al. (2010) and Micelotta et al. (2010a,b). Two supernova remnants were studied- the North Polar Spur (NPS) and the Cygnus Loop. The data for PAHs were obtained from the WISE W3 12 micron all-sky map processed by Meisner & Finkbeiner (2014), and the data for the larger grains come from the IRAS 100 micron all-sky map processed by Schlegel, Finkbeiner & Davis (1998). After obtaining a control PAH/large grain intensity ratio of ~2.8 (DN/px)/(MJy/sr) from two high latitude clouds, MBM 30 and MBM 32, we found that the intensity ratios across the NPS and Cygnus Loop were not far off- ~2.7 (DN/px)/(MJy/sr) and ~3.1 (DN/px)/(MJy/sr), respectively- showing no evidence of selective large-scale PAH destruction in supernova remnants. The individual intensities for both PAHs and large grains do decrease inside the Cygnus Loop, however, suggesting a decrease in abundances of both grain types, which could mean total dust grain destruction with the normal ratios coming from foreground and background dust located in the line of sight of the remnant. In addition, temperature and E(B-V) measurements taken from calibrated IRAS images show that while the dust column density increases in the Eastern Veil of the Cygnus Loop, the dust temperature reaches a local maximum, indicating the heating of large grains by interaction with the hot gas in the remnant. The PAH/large grain ratio in the Eastern Veil does decrease and could be indicative of currently ongoing active grain destruction there, with the PAHs being destroyed on a more rapid timescale than the large grains.We are grateful for financial support from the NSF REU Program grant to the Department of Physics & Astronomy at

  13. 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.

  14. 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%.

  15. 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.

  16. 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).

  17. 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.

  18. 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.

  19. Dissecting the Cygnus region with TeV gamma rays and neutrinos

    SciTech Connect

    Beacom, John F.; Kistler, Matthew D.

    2007-04-15

    Recent Milagro observations of the Cygnus region have revealed both diffuse TeV gamma-ray emission and a bright and extended TeV source, MGRO J2019+37, which seems to lack an obvious counterpart at other wavelengths. Additional study of this curious object also promises to provide important clues concerning one of the Milky Way's most active environments. We point out some of the principal facts involved by following three modes of attack. First, to gain insight into this mysterious source, we consider its relation to known objects in both the Cygnus region and the rest of the Galaxy. Second, we find that a simple hadronic model can easily accommodate Milagro's flux measurement (which is at a single energy), as well as other existing observations spanning nearly 7 orders of magnitude in gamma-ray energy. Third, since a hadronic gamma-ray spectrum necessitates an accompanying TeV neutrino flux, we show that IceCube observations may provide the first direct evidence of a Galactic cosmic-ray accelerator.

  20. On the nature of the episodic gamma-ray flare observed in Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Del Valle, M. V.; Romero, G. E.; Orellana, M.

    The high-mass microquasar Cygnus X-1, the best established candidate for a stellar-mass black hole, has been detected in a flaring state at very high energies, E > 200 GeV (Albert et al. 2007). The observation was per- formed by the Atmospheric Cherenkov Telescope MAGIC. It is the first experimental evidence of very high energy emission produced by a galactic stellar-mass black hole. The observed high energy excess occurred in coin- cidence with an X-ray flare. The flare took place at orbital phase = 0.91, being = 1 the moment when the black hole is behind the companion star. In this configuration the absorption of gamma-ray photons produced by photon-photon annihilation with the stellar field is expected to be the highest. We present detailed calculations of the gamma-ray opacity due to pair creation along the whole orbit, and for different locations of the emitter (height above the compact object). We discuss the location of the gamma- ray producing region in Cygnus X-1 and the energetics required to produce the flare.

  1. 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. PMID:16094361

  2. Polarized mid-infrared synchrotron emission in the core of Cygnus A

    SciTech Connect

    Lopez-Rodriguez, E.; Packham, C.; Tadhunter, C.; Mason, R.; Perlman, E.; Alonso-Herrero, A.; Ramos Almeida, C.; Rodríguez-Espinosa, J. M.; Levenson, N. A.; Álvarez, C. A.; Ramírez, E. A.; Telesco, C. M.

    2014-10-01

    We present high-angular (∼0.''4) resolution mid-infrared (MIR) polarimetric observations in the 8.7 μm and 11.6 μm filters of Cygnus A using CanariCam on the 10.4 m Gran Telescopio CANARIAS. A highly polarized nucleus is observed with a degree of polarization of 11% ± 3% and 12% ± 3% and a position angle of polarization of 27° ± 8° and 35° ± 8° in a 0.''38 (∼380 pc) aperture for each filter. The observed rising of the polarized flux density with increasing wavelength is consistent with synchrotron radiation from the parsec-scale jet close to the core of Cygnus A. Based on our polarization model, the synchrotron emission from the parsec-scale jet is estimated to be 14% and 17% of the total flux density in the 8.7 μm and 11.6 μm filters, respectively. A blackbody component with a characteristic temperature of 220 K accounts for >75% of the observed MIR total flux density. The blackbody emission arises from a combination of (1) dust emission in the torus; and (2) diffuse dust emission around the nuclear region, but the contributions of the two components cannot be well-constrained in these observations.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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

  9. Kinematics of the Central Kiloparsec in Cygnus A from AO Integral Field Spectroscopy

    NASA Astrophysics Data System (ADS)

    Aylor, Kevin; Rude, G.; Medling, A.; Canalizo, G.; Max, C. E.; Antonucci, R. R.

    2013-01-01

    We present Keck Integral Field Unit observations and long-slit spectroscopy of the central regions of Cygnus A using laser guide star adaptive optics. Our near-IR images show a bi-conic structure clearly seen in Pa-alpha emission and a more flattened structure perpendicular to the axis of the radio jets that is only visible in H_2 emission. Both of these structures are strongly suggestive of an obscuring torus around a heavily extinguished quasar nucleus. We use the integral field spectroscopy to develop velocity maps and model the kinematics of the entire region. We thus set constraints on the torus geometry and obtain an estimate for the mass of the supermassive black hole.

  10. 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

  11. Broadband Emission Spectra from the Cygnus X-3 Jet in the Soft Spectral State

    NASA Astrophysics Data System (ADS)

    Zhang, Jian-Fu; Lu, Ju-Fu

    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.

  12. 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.

  13. Multi-frequency observation of Galactic micro-quasar Cygnus X-3 during flare

    NASA Astrophysics Data System (ADS)

    Patra, D.; Pal, S.; Ishwara-Chandra, C. H.; Rao, A. P.

    We studied the multi-frequency radio observations of the Galactic micro-quasar Cygnus X-3 using the Giant Metrewave Radio Telescope at 244, 325, 614 and 1280 MHz and Very Large Array at 8.43, 22.5 and 43.3 GHz during various flaring activities between 2006 to 2009. We have calculated the two point spectral index from the simultaneous observations at 244 and 614 MHz. These spectral index varies from positive (optically thick) and negative (optically thin) values which is consistent with the synchrotron self absorption model. We calculated some physical parameters such as the size of emitting region, turn over frequency and corresponding peak flux using the synchrotron self absorption model. The size of the emitting region are different at different time of the flare.

  14. 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.

  15. Ultraviolet, X-ray, and infrared observations of HDE 226868 equals Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Treves, A.; Chiappetti, L.; Tanzi, E. G.; Tarenghi, M.; Gursky, H.; Dupree, A. K.; Hartmann, L. W.; Raymond, J.; Davis, R. J.; Black, J.

    1980-01-01

    During April, May, and July of 1978, HDE 226868, the optical counterpart of Cygnus X-1, was repeatedly observed in the ultraviolet with the IUE satellite. Some X-ray and infrared observations have been made during the same period. The general shape of the spectrum is that expected from a late O supergiant. Strong absorption features are apparent in the ultraviolet, some of which have been identified. The equivalent widths of the most prominent lines appear to be modulated with the orbital phase. This modulation is discussed in terms of the ionization contours calculated by Hatchett and McCray, for a binary X-ray source in the stellar wind of the companion.

  16. 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).

  17. Joint BeppoSAX/RossiXTE Observation of Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Piraino, S.; Santangelo, A.; Kaaret, P.

    2001-09-01

    We report on a joint BeppoSAX/RossiXTe observation of the Z-type low mass X-ray binary Cygnus X-2. The source was in the so-called high overall intensity state and in less than 24 hours went through all three branches of the Z-track. The continuum X-ray spectrum could be described by the absorbed sum of a soft thermal component and a Comptonized component. The timing power spectrum showed several components including QPO in the ranges 28-50 Hz while the source was on the horizontal branch (HBO). We found that the HBO frequency was well correlated with the parameters of soft thermal component in the X-ray spectrum.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Deeper Chandra Follow-up of Cygnus TeV Source Perpetuates Mystery

    NASA Astrophysics Data System (ADS)

    Butt, Yousaf M.; Drake, Jeremy; Benaglia, Paula; Combi, Jorge A.; Dame, Thomas; Miniati, Francesco; Romero, Gustavo E.

    2006-05-01

    A 50 ks Chandra observation of the unidentified TeV source in Cygnus reported by the HEGRA collaboration reveals no obvious diffuse X-ray counterpart. However, 240 pointlike X-ray sources are detected within or nearby the extended TeV J2032+4130 source region, of which at least 36 are massive stars and two may be radio emitters. That the HEGRA source is a composite, having as a counterpart the multiple pointlike X-ray sources we observe, cannot be ruled out. Indeed, the distribution of pointlike X-ray sources appears nonuniform and concentrated broadly within the extent of the TeV source region. We offer a hypothesis for the origin of the very high energy gamma-ray emission in Cyg OB2 based on the local acceleration of TeV-range cosmic rays and the differential distribution of OB versus less massive stars in this association.

  3. Multifrequency radio observations of Cygnus A - Spectral aging in powerful radio galaxies

    NASA Technical Reports Server (NTRS)

    Carilli, C. L.; Perley, R. A.; Dreher, J. W.; Leahy, J. P.

    1991-01-01

    A detailed analysis of the radio spectrum across the lobes of Cygnus A is presented in order to critically test the synchroton spectral aging theory. The results are in good agreement with the jet model for powerful radio galaxies, involving particle acceleration at the hot spots and outflow into the radio lobes, with subsequent energy loss due to synchrotron radiation. The hot spot spectra are well represented by a spectral aging model involving continuous injection of relativistic particles. Both hot spots have spectral break frequencies around 10 GHz. An injection index of 0.5 is found for both hot spots, consistent with diffusive shock acceleration at a strong nonrelativistic shock in a Newtonian fluid. The LF hot spot emission spectrum falls below the injected power law. This effect is isolated to the hot spots, and is best explained by a low-energy cutoff in the particle distribution.

  4. 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.

  5. Chaos and random processes in the x ray variability of Cygnus X-1

    SciTech Connect

    Lochner, J.C.

    1989-01-01

    The temporal variability of the x ray emission of the black hole candidate Cygnus X-1 was examined in an attempt to better characterize the source of the aperiodic variability. The emission is generally believed to come from a turbulent accretion disk surrounding the black hole. Two analysis techniques were applied to low energy x ray light curves: a search for a low-dimensional chaotic attractor; and a new technique to further develop the standard shot noise model. The search for a low-dimensional attractor tests the hypothesis that deterministic chaotic dynamics underlie the accretion disk physics. Using a standard time delay embedding, the phase space trajectory was constructed from the light curve, and the correlation integral was used to determine the dimension of the resulting manifold. The difficulties encountered by this method were investigated with a finite number of data points and a noise level not usually encountered in other applications. The data were not found to indicate that a low-dimensional attractor underlies the variability. This implies that the turbulence in the disk is well developed, and that simple models cannot reliably reconstruct the temporal variability. Shot noise models have long been used as phenomenological, stochastic models for the variability of Cygnus X-1, relying on random pulses of emission, each having a fixed shape and duration. A distribution of shot lengths from 0.01 s to 6.0 s was introduced to reproduce the power density spectrum of the data. The shot profile and the fraction of the emission are found by fitting the phase portrait of the data with trial shot models. Both sets of data are found to be consistent with shots having a symmetric exponential rise and decay, and with the shot amplitude as a power law function of the shot length. These results are interpreted in terms of a distribution of magnetic flares in the disk.

  6. 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.

  7. Electron-ion equilibrium and shock precursors in the northeast limb of the Cygnus Loop

    SciTech Connect

    Medina, Amber A.; Raymond, John C.; Edgar, Richard J.; Caldwell, Nelson; Milisavljevic, Dan; Fesen, Robert A. E-mail: jraymond@cfa.harvard.edu E-mail: amedina7@nmsu.edu

    2014-08-10

    We present an observational study using high-resolution echelle spectroscopy of collisionless shocks in the Cygnus Loop supernova remnant. Measured Hα line profiles constrain pre-shock heating processes, shock speeds, and electron-ion equilibration (T{sub e} /T{sub i} ). The shocks produce faint Hα emission line profiles, which are characterized by narrow and broad components. The narrow component is representative of the pre-shock conditions, while the broad component is produced after charge transfer between neutrals entering the shock and protons in the post-shock gas, thus reflecting the properties of the post-shock gas. We observe a diffuse Hα region extending about 2.'5 ahead of the shock with line width ∼29 km s{sup –1}, while the Hα profile of the shock itself consists of broader than expected narrow (36 km s{sup –1}) and broad (250 km s{sup –1}) components. The observed diffuse emission arises in a photoionization precursor heated to about 18,000 K by He I and He II emission from the shock, with additional narrow component broadening originating from a thin cosmic-ray precursor. Broad to narrow component intensity ratios of ∼1.0 imply full electron-ion temperature equilibration T{sub e} ≅ T{sub i} in the post-shock region. Broad component line widths indicate shock velocities of about 400 km s{sup –1}. Combining the shock velocities with proper motions suggests that the distance to the Cygnus Loop is ∼890 pc, significantly greater than the generally accepted upper limit of 637 pc.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. Multiband observations of Cygnus A: A study of pressure balance in the core of a powerful radio galaxy

    NASA Technical Reports Server (NTRS)

    Carilli, Chris; Conner, Sam; Dreher, John; Perley, Rick

    1990-01-01

    Cygnus A is a powerful double radio source associated with a giant elliptical galaxy at the center of a poor cluster of galaxies. The radio source also sits within the core radius of a dense, cooling flow, x ray emitting cluster gas. Optical spectroscopy and narrow band imaging have revealed copious amounts of narrow line emission from the inner 20 kpc of the associated galaxy. Researchers assume H sub o = 75 km sec (-1) Mpc(-1). Discussed here are the pressures in the three components of the Interstellar Medium (ISM) (i.e., the radio, x ray, and line emitting fluids) within a radius of about 15 kpc of the active nucleus of the Cygnus A galaxy.

  13. 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.

  14. 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.

  15. 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.

  16. XMM-Newton observations across the Cygnus Loop from northeastern rim to southwestern rim

    NASA Astrophysics Data System (ADS)

    Katsuda, Satoru; Tsunemi, Hiroshi

    We have observed the Cygnus Loop from the northeast (NE) to the southwest (SW) with XMM-Newton. We extracted spectra from 3‧-spaced annular regions across the Loop and fitted them either with a one-kTe-component non-equilibrium ionization (NEI) model or with two-kTe-component NEI model. We found that the two-kTe-component model yields significantly better fits in almost all the spectra than the one-kTe-component model. Judging from the abundances, the high-kTe-component in the two-temperature model must be fossil ejecta while the low-kTe-component comes from the swept-up interstellar medium (ISM). The distributions of Ne, Mg, Si, and S for fossil ejecta appear to retain the onion-skin structure at the time of a supernova explosion, suggesting that significant overturning of the ejecta has not occurred yet. Comparing the relative abundances of fossil ejecta estimated for the entire Cygnus Loop with those from theoretical calculations for Type-II SN, the mass of the progenitor star is likely to be ˜13 M⊙. The trends of the radial profiles of kTe and emission integral for the swept-up ISM are adequately described by the Sedov model, suggesting that the swept-up ISM is concentrated in a shell-like structure. Comparing our data with the Sedov model, we found the ambient medium density to be ˜0.7 cm-3. Then, we estimated the total mass of the swept-up ISM and the age of the remnant to be ˜130 M⊙ and 13,000 years, respectively. Note that if the explosion occurred within a stellar wind cavity, then the density in the cavity, the total swept-up mass in the cavity, and the age of the remnant are estimated to be ˜0.14 cm-3, ˜25 M⊙, and ˜10,000 years, respectively.

  17. 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.

  18. 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.

  19. 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.

  20. Shot model parameters for Cygnus X-1 through phase portrait fitting

    SciTech Connect

    Lochner, J.C.; Swank, J.H.; Szymkowiak, A.E. )

    1991-07-01

    Shot models for systems having about 1/f power density spectrum are developed by utilizing a distribution of shot durations. Parameters of the distribution are determined by fitting the power spectrum either with analytic forms for the spectrum of a shot model with a given shot profile, or with the spectrum derived from numerical realizations of trial shot models. The shot fraction is specified by fitting the phase portrait, which is a plot of intensity at a given time versus intensity at a delayed time and in principle is sensitive to different shot profiles. These techniques have been extensively applied to the X-ray variability of Cygnus X-1, using HEAO 1 A-2 and an Exosat ME observation. The power spectra suggest models having characteristic shot durations lasting from milliseconds to a few seconds, while the phase portrait fits give shot fractions of about 50 percent. Best fits to the portraits are obtained if the amplitude of the shot is a power-law function of the duration of the shot. These fits prefer shots having a symmetric exponential rise and decay. Results are interpreted in terms of a distribution of magnetic flares in the accretion disk. 30 refs.

  1. 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.

  2. 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.

  3. 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.

  4. High energy X-ray spectra of cygnus XR-1 observed from OSO-8

    NASA Technical Reports Server (NTRS)

    Dolan, J. F.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.

    1978-01-01

    X-ray spectra of Cygnus XR-1 were measured with the scintillation spectrometer on board the OSO-8 satellite during a period of one and one-half to three weeks in each of the years from 1975 to 1977. Observations were made when the source was both in a high state and in a low state. Typical spectra of the source between 15 and 250 keV are presented. The observed pivoting effect is consistent with two temperature accretion disk models of the X-ray emitting region. No significant break in the spectrum occurred at energies up to 150 keV. The high state as defined in the 3 to 6 keV bandwidth was found to be the higher luminosity state of the X-ray source. One transition from a low to a high state occurred during observations. The time of occurrence of this and other transitions is consistent with the hypothesis that all intensity transitions occur near periastron of the binary system, and that such transitions are caused by changes in the mass transfer rate between the primary and the accretion disk around the secondary.

  5. Telecentric Zoom Lens Designed for the Cygnus X-Ray Source

    SciTech Connect

    Malone, R. M.; Baker, S. A.; Brown, K. K.; Curtis, A. H.; Esquibel, D. L.; Frayer, D. K.; Frogget, B. C.; Frogget, K. G.; Kaufman, M. I.; Smith, A. S.; Tibbitts, A.; Howe, R. A.; Huerta, J. A.; McGillivray, K. D.; Droemer, D. W.; Crain, M. D.; Haines, T. J.; King, S. P.

    2013-07-01

    Cygnus is a high-energy radiographic x-ray source. Three large zoom lenses have been assembled to collect images from large scintillators. A large elliptical pellicle (394 × 280 mm) deflects the scintillator light out of the x-ray path into an eleven-element zoom lens coupled to a CCD camera. The zoom lens and CCD must be as close as possible to the scintillator to maximize light collection. A telecentric lens design minimizes image blur from a volume source. To maximize the resolution of objects of different sizes, the scintillator and zoom lens are translated along the x-ray axis, and the zoom lens magnification changes. Zoom magnification is also changed when different-sized recording cameras are used (50 or 62 mm square format). The LYSO scintillator measures 200 × 200 mm and is 5 mm thick. The scintillator produces blue light peaking at 435 nm, so special lens materials are required. By swapping out one doublet and allowing all other lenses to be repositioned, the zoom lens can also use a CsI(Tl) scintillator that produces green light centered at 540 nm. All lenses have an anti-reflective coating for both wavelength bands. Two sets of doublets, the stop, the scintillator, and the CCD camera move during zoom operations. One doublet has x-y compensation. Each zoom lens uses 60 lb of glass inside the 425 lb mechanical structure and can be used in either a vertical or horizontal orientation.

  6. Rapid variability of 10-140 keV X-rays from Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Nolan, P. L.; Gruber, D. E.; Matteson, J. L.; Peterson, L. E.; Rothschild, R. E.; Doty, J. P.; Levine, A. M.; Lewin, W. H. G.; Primini, F. A.

    1981-01-01

    On five occasions in 1977 and 1978, Cygnus X-1 was observed using the low-energy detectors of the UCSD/MIT Hard X-ray and Low-Energy Gamma Ray experiment on the HEAO 1 satellite. Rapid (times between 0.08 and 1000 sec) variability was found in the 10-140 keV band. The power spectrum was white for frequencies between 0.001 and 0.05 Hz and was proportional to the inverse of the frequency for frequencies between 0.05 and 3 Hz, indicating correlations on all time scales less than approximately 20 s. The shape of the energy spectrum was correlated with intensity; it was harder at higher intensity. If the emission is produced by Comptonization of a soft photon flux in a hot cloud, the heating of the cloud cannot be constant; it must vary on time scales up to approximately 20 s. A variable accretion rate could cause the observed effects.

  7. 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.

  8. 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.

  9. Ultraviolet, Optical and X-Ray Imaging of Selected Cygnus Loop Fields

    NASA Technical Reports Server (NTRS)

    Danforth, C. W.; Cornett, R. H.; Blair, W. P.; Stecher, T. P.; Levenson, N. A.

    1999-01-01

    During the Astro-1 and Astro-2 Space Shuttle missions in 1990 and 1995, far ultraviolet (FUV) images of five 40 ft diameter fields around the rim of the Cygnus Loop Super Nova Remnants (SNR) were observed with the Ultraviolet Imaging Telescope (UIT). These fields sample a broad range of SNR conditions including both radiative and non-radiative shocks in various geometries and scales. The UIT B5 band images discussed here sample predominantly ion-C4 lambda 1550 and the 2-photon continuum. Smaller contributions are made by emission lines of ion He-2 lambda 1640 and ion 03 lambda 1666. A unique aspect of the B5 band is its ability to sample the hydrogen 2-photon continuum from regions where the gas is recombining. We present these new FUV images and compare them with optical H-alpha and [ion O13], and ROSAT HRI X-ray images. In non-radiative shocks, existing 2-photon flux measurements from spectra and the H-alpha images suggest we are seeing approximately equal contributions from 2-photon and ion C4 emission. In radiative filaments, however, shock models and our images suggest ion C4 should dominate while spectra of specific locations seem to indicate that 2-photon emission dominates. We surmise that spectral observations on specific bright filaments have decreased locally-observed levels of ion C41 emission due to resonance scattering in that line.

  10. 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.

  11. 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).

  12. 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.

  13. Multiwavelength study of Cygnus A - III. Evidence for relic lobe plasma

    NASA Astrophysics Data System (ADS)

    Steenbrugge, Katrien C.; Heywood, Ian; Blundell, Katherine M.

    2010-01-01

    We study the particle energy distribution in the cocoon surrounding Cygnus A, using radio images between 151 MHz and 15 GHz and a 200 ks Chandra Advanced CCD Imaging Spectrometer-Imaging (ACIS-I) image. We show that the excess low-frequency emission in the lobe further from the Earth cannot be explained by absorption or excess adiabatic expansion of the lobe or a combination of both. We show that this excess emission is consistent with emission from a relic counterlobe and a relic counterjet that are being re-energized by compression from the current lobe. We detect hints of a relic hotspot at the end of the relic X-ray jet in the more distant lobe. We do not detect relic emission in the lobe nearer to the Earth as expected from light traveltime effects assuming intrinsic symmetry. We determine that the duration of the previous jet activity phase was slightly less than that of the current jet-active phase. Further, we explain some features observed at 5 and 15 GHz as due to the presence of a relic jet.

  14. 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).

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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..

  20. Innate Immunity in Lobsters: Partial Purification and Characterization of a Panulirus cygnus Anti-A Lectin.

    PubMed

    Flower, Robert L P

    2012-01-01

    A lectin detected in haemolymph from the Australian spiny lobster Panulirus cygnus agglutinated human ABO Group A cells to a higher titre than Group O or B. The lectin also agglutinated rat and sheep erythrocytes, with reactivity with rat erythrocytes strongly enhanced by treatment with the proteolytic enzyme papain, an observation consistent with reactivity via a glycolipid. The lectin, purified by affinity chromatography on fixed rat-erythrocyte stroma, was inhibited equally by N-acetylglucosamine and N-acetylgalactosamine. Comparison of data from gel filtration of haemolymph (behaving as a 1,800,000 Da macromolecule), and polyacrylamide gel electrophoresis of purified lectin (a single 67,000 Da band), suggested that in haemolymph the lecin was a multimer. The purified anti-A lectin autoprecipitated unless the storage solution contained chaotropic inhibitors (125 mmol/L sucrose: 500 mmol/L urea). The properties of this anti-A lectin and other similar lectins are consistent with a role in innate immunity in these invertebrates. PMID:22462000

  1. Multi-frequency observation of high mass X-ray binary Cygnus X-3 during flares

    NASA Astrophysics Data System (ADS)

    Pal, Sabyasachi; Patra, Dusmanta; Ishwara-Chandra, C. H.; Rao, A. P.

    2016-07-01

    We studied the multi-frequency properties of the Galactic high mass X-ray binary Cygnus X-3 during various flaring activities using The Rossi X-ray Timing Explorer (RXTE), the Giant Metrewave Radio Telescope (GMRT), Jansky Very Large Array (JVLA) etc. The flare of 2006 May-June was one of the largest flare in the history of the source which is thoroughly discussed. We also observed few large flares of this source between 2007 and 2009. We commented on correlation and lag between X-ray and radio emissions during flares. We construct the radio spectrum of the source in the rising and fading phase of flares using GMRT, JVLA and published results using RATAN. We clearly see that the turn-over frequency is shifting towards lower frequencies as the flares evolve gradually. The two point spectral index between 614 MHz and 235 MHz varies from positive (optically thick) and negative (optically thin) values which is consistent with the synchrotron self absorption model. We calculated some physical parameters of the source such as the size of emitting region using the synchrotron self absorption model. The size of the emitting region expands with the flare. We estimate the velocity of the expansion of the blob in the non-relativistic range from the expansion of the size of emitting region.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Constraints on the inclination and masses of the HDE 226868/Cygnus X-1 system from the observations

    NASA Technical Reports Server (NTRS)

    Davis, R.; Hartmann, L.

    1983-01-01

    Analyses of two high-dispersions IUE spectra of HDE 226868 (the optical counterpart of Cygnus X-1) are combined with studies of low-dispersion IUE spectra to provide a more accurate determination of the variation of C IV stellar wind absorption as a function of orbital phase. By incorporating these observational results into an analysis of the structure of the X-ray ionization cavity in the stellar wind, it is found that the orbital inclination must lie between 36 and 67 deg, leading to a mass for the compact object between 5.7 and 11.2 solar masses.

  10. 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.

  11. Alignment and Testing of a Telecentric Zoom Lens Used for the Cygnus X-ray Source

    SciTech Connect

    Malone, R. M.; Baker, S. A.; Brown, K. K.; Castaneda, J. J.; Curtis, A. H.; Danielson, J.; Droemer, D. W.; Esquibel, D. L.; Haines, T. J.; Hollabaugh, J. S.; Howe, R. A.; Huerta, J. A.; King, N. S. P.; Lutz, S. S.; Kaufman, M. I.; McGillivray, K. D.; Smith, A. D.; Stokes, B. M.; Tibbitts, A.

    2013-09-01

    Cygnus is a high-energy radiographic x-ray source. Three large zoom lenses have been assembled to collect images from large scintillators. A large elliptical pellicle (394 × 280 mm) deflects the scintillator light out of the x-ray path into an eleven-element zoom lens coupled to a CCD camera. The zoom lens and CCD must be as close as possible to the scintillator to maximize light collection. A telecentric lens design minimizes image blur from a volume source. To maximize the resolution of objects of different sizes, the scintillator and zoom lens are translated along the x-ray axis, and the zoom lens magnification changes. Zoom magnification is also changed when different-sized recording cameras are used (50 or 62 mm square format). The LYSO scintillator measures 200 × 200 mm and is 5 mm thick. The scintillator produces blue light peaking at 435 nm, so special lens materials are required. By swapping out one doublet and allowing all other lenses to be repositioned, the zoom lens can also use a CsI(Tl) scintillator that produces green light centered at 540 nm (for future operations). All lenses have an anti-reflective coating for both wavelength bands. Two sets of doublets, the stop, the scintillator, and the CCD camera move during zoom operations. One doublet has x-y compensation. Alignment of the optical elements was accomplished using counter propagating laser beams and monitoring the retro-reflections and steering collections of laser spots. Each zoom lens uses 60 lb of glass inside the 425 lb mechanical structure, and can be used in either vertical or horizontal orientation.

  12. 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.

  13. 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.

  14. 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.

  15. Design and Assembly of a Telecentric Zoom Lens for the Cygnus X-ray Source

    SciTech Connect

    Malone, R M; Brown, K K; Curtis, A H; Esquibel, D L; Frayer, D K; Frogget, B C; Furlanetto, M R; Garten, J R; Haines, T J; Howe, R A; Huerta, J A; Kaufman, M I; King, N.S. P; Lutz, S S; McGillivray, K D; Smith, A S

    2012-10-01

    Cygnus is a high-energy radiographic x-ray source. The rod-pinch x-ray diode produces a point source measuring 1 mm diameter. The target object is placed 1.5 m from the x-ray source, with a large LYSO scintillator at 2.4 m. Different-sized objects are imploded within a containment vessel. A large pellicle deflects the scintillator light out of the x-ray path into an 11-element zoom lens coupled to a CCD camera. The zoom lens and CCD must be as close as possible to the scintillator to maximize light collection. A telecentric lens design minimizes image blur from a volume source. To maximize the resolution of test objects of different sizes, the scintillator and zoom lens can be translated along the x-ray axis. Zoom lens magnifications are changed when different-sized scintillators and recording cameras are used (50 or 62 mm square format). The LYSO scintillator measures 200 × 200 mm and is 5 mm thick. The scintillator produces blue light peaking at 435 nm, so special lens materials are required. By swapping out one lens element and allowing all lenses to move, the zoom lens can also use a CsI(Tl) scintillator that produces green light centered at 550 nm. All lenses are coated with anti-reflective coating for both wavelength bands. Two sets of doublets, the stop, and the CCD camera move during zoom operations. One doublet has XY compensation. The first three lenses use fused silica for radiation damage control. The 60 lb of glass inside the 340 lb mechanical structure is oriented vertically.

  16. 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.

  17. Toxicity of Anacostia River, Washington, DC, USA, sediment fed to mute swans (Cygnus olor)

    SciTech Connect

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

    2000-03-01

    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. The authors did not study all potential toxic effects, but, on the basis of those that they did consider, they concluded that the treated swans were basically healthy after a chronic exposure to the sediment.

  18. Annual use of man-made wetlands by the mute swan (Cygnus olor).

    PubMed

    Gayet, Guillaume; Matthieu, Guillemain; François, Mesleard; Hervé, Fritz; Laurence, Curtet; Joël, Broyer

    2013-05-15

    This is essential to understand habitat selection by wildlife to manage habitats and populations. Studying the annual use of aquatic habitats provides information on how to manage wetlands for waterfowl, and to predict possible detrimental effects associated with extended usage by these birds. This is particularly important for species like the mute swan (Cygnus olor Gmelin), given its recent dramatic demographic expansion, causing concern in both Europe and America. We studied the extent of usage (swan.days.ha(-1)) of habitat patches by mute swans in a heterogeneous and fluctuating fishpond landscape. We assessed seasonal differences of swan usage of fishponds, annual variation for a given fishpond, and determined which habitat factors drive swan usage over the year. The seasonal use pattern was regular: a similar proportion of fishponds was used heavily, moderately or lightly in all seasons. Flocking throughout the year and breeding during summer were associated with heavy use of fishponds, i.e. large number of swan.days.ha(-1). Flocking on some fishponds during several successive seasons demonstrated that some waterbody provide valuable habitats over time for swans. However, swans did not use individual fishponds to the same extent each season, mostly depending on the fluctuating ecological requirements of swans and variation in habitat properties. Agricultural practices on fishponds drastically affected swan usage during autumn and winter: formerly dried fishponds were used preferentially once reflooded. The specific agricultural crops used during the drought period had no influence though. The large-sized fishponds and fishponds within a dense network of waterbody were the most heavily used by swans throughout the year. Our results may thus be helpful to predict and prevent possible habitat damage by swans. They also provide information on habitats that are valuable for waterfowl species in general, by using mute swans as a proxy for waterfowl requirements

  19. 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

  20. 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).

  1. A self-consistent model for the long-term gamma-ray spectral variability of Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Melia, Fulvio; Misra, Ranjeev

    1993-01-01

    The long-term transitions of the black hole candidate Cygnus X-1 (between the states gamma-1, gamma-2, and gamma-3) include the occasional appearance of a strong nearly-MeV bump (gamma-1), whose strength appears to be anticorrelated with the continuum flux (below 400 keV) due to the Compton upscattering of cold disk photons by the inner, hot corona. We develop a self-consistent disk picture in which the bump is seen as due to the self-Comptonization of bremsstrahlung photons emitted predominantly near the plane of the corona itself. A decrease by a factor of about two in the viscosity parameter alpha is responsible for quenching this bump and driving the system to the gamma-2 state, whereas a transition from gamma-2 to gamma-3 appears to be induced by an increase of about 25 percent in the accretion rate M. In view of the fact that most of the transitions observed in this source seem to be of the gamma-2-gamma-3 variety, we conclude that much of the long-term gamma-ray spectral variability in Cygnus X-1 is due to these small fluctuations in M. The unusual appearance of the gamma-1 state apparently reflects a change in the dissipative processes within the disk.

  2. A Comparison of Ultraviolet, Optical, and X-Ray Imagery of Selected Fields in the Cygnus Loop

    NASA Technical Reports Server (NTRS)

    Danforth, Charles W.; Cornett, Robert H.; Levenson, N. A.; Blair, William P.; Stecher, Theodore P.

    1999-01-01

    During the Astro-1 and Astro-2 Space Shuttle missions in 1090 and 199.5, far ultraviolet (FUV) images of five 40' diameter fields around the rim of the Cygnus Loop supernova remnant were observed with the Ultraviolet Imaging Telescope (UIT). These fields sampled a broad range of conditions including both radiative and nonradiative shocks in various geometries and physical scales. In these shocks, the UIT B5 band samples predominantly C IV Lambda-1550 and the hydrogen two-photon recombination continuum. Smaller contributions are made by emission lines of He II Lambda-1640 and O III] Lambda-1665. We present these new FUV images and compare them with optical H-alpha and [O III], and ROSAT HRI X-ray images. Comparing the UIT images with those from the other bands provides new insights into the spatial variations and locations of these different types of emission. By comparing against shock model calculations and published FUV spectroscopy at select locations, we surmise that resonance scattering in the strong FUV permitted lines is widespread in the Cygnus Loop. especially in the bright optical filaments typically selected for observation in most previous studies.

  3. A deep survey of the Galactic plane at very high energies

    NASA Astrophysics Data System (ADS)

    Chow, Yeuk Chun

    The Cygnus region of the Galactic plane contains many known supernova remnants, pulsars, X-Ray sources and GeV emitters which makes it a prime candidate for a Very High Energy (VHE) survey study in the Northern Hemisphere. VERITAS, an array of atmospheric Cherenkov telescopes located in southern Arizona, USA, is the most sensitive very high energy gamma-ray telescope in operation today. Between April 2007 and Fall 2009, VERITAS carried out an extensive survey of the Cygnus region between 67 and 82 degrees in Galactic longitude and between -1 and 4 degrees in Galactic latitude. The survey, comprising more than 140 hours of observations, reached an average VHE flux sensitivity of better than 5% of the Crab Nebula flux at energies above 200 GeV, making it the most sensitive VHE gamma-ray survey ever done in the northern Hemisphere. The survey data set revealed two highly probable gamma-ray sources in the region. A detailed description of the observational strategy and analysis methodology of the survey are given and a discussion of the scientific implications resulting from the survey is provided.

  4. 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

  5. Common Gamma-Ray Spectral Properties of GROJ0422+32 and CYGNUS X-1

    NASA Astrophysics Data System (ADS)

    Ling, J. C.; Wheaton, Wm. A.

    2003-03-01

    We report soft gamma-ray (30 keV to 1.7 MeV) spectral properties in the black hole GROJ0422+32, observed during its first known outburst in 1992, and similar to properties of Cygnus X-1 during its low-to-high state transitions in 1994 and 1996 (see Ling & Wheaton, 2003). In both cases, the high-intensity (``gamma2'') spectrum consists of two components: a Comptonized shape below 300 keV, plus a steep power-law tail above 300 keV. By contrast, the low-intensity spectrum (``gamma0'') has a power-law shape with an index of ˜2. The two spectra cross at ˜600 keV for GROJ0422+32, or about 1 MeV for Cyg X-1. We suggest a scenario for interpreting these common spectral features by including a separate non-thermal source region, possibly a jet, in the ADAF model of Esin et al (1998). During the high-intensity gamma2 state, the system consists of a hot inner corona, a cooler outer thin disk, and a region that produced the variable power-law gamma-ray emission. In this condition, the transition radius of the disk is ˜100 Schwarzschild radii. Electrons in the hot corona up-scatter the low-energy photons, produced both within the corona as well as from the outer disk, to form the Comptonized component that dominates the spectrum in the 35-300 keV range. The same electrons also down-scatter high energy (>10 MeV) photons produced nonthermally in the ``jet'' region, forming the softer power-law component observed in the 0.3-1 MeV range. During the low-intensity gamma0 state, a large soft flux cools the inner corona, and moves the transition radius inward, close to the event horizon. Under this condition, the Comptonized component in the 35-300 keV range is suppressed, and the source spectrum is dominated by the unperturbed power-law emission produced in the non-thermal source region, with a characteristic index of ˜2. The work described in this paper was carried out by the Jet Propulsion Laboratory, under the contract with the National Aeronautics and Space Administration

  6. 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

  7. 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.

  8. 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.

  9. CHANDRA IMAGING AND SPECTROSCOPY OF THE EASTERN XA REGION OF THE CYGNUS LOOP SUPERNOVA REMNANT

    SciTech Connect

    McEntaffer, R. L.; Brantseg, T.

    2011-04-01

    The XA region of the Cygnus Loop is a bright knot of X-ray emission on the eastern edge of the supernova remnant. The emission results from the interaction of the supernova blast wave with density enhancements at the edge of a precursor formed cavity. However, this interaction is complex given the irregular morphology of the cavity wall. To study the nature and origin of the X-ray emission, we use high spatial resolution images from Chandra. We extract spectra from these images to analyze the physical conditions of the plasma. Our goal is to probe the density of various regions to form a picture of the cavity wall and characterize the interaction between this supernova and the local interstellar medium. We find that a series of regions along the edge of the X-ray emission appears to trace out the location of the cavity wall. The best-fit plasma models result in two temperature component equilibrium models for each region. The low-temperature components have densities that are an order of magnitude higher than the high-temperature components. The high-density plasma may exist in the cavity wall where it equilibrates rapidly and cools efficiently. The low-density plasma is interior to the enhancement and heated further by a reverse shock from the wall. Calculations of shock velocities and timescales since shock heating are consistent with this interpretation. Furthermore, we find a bright knot of emission indicative of a discrete interaction of the blast wave with a high-density cloud in the cavity wall with a size scale {approx}0.1 pc. Aside from this, other extractions made interior to the X-ray edge are confused by line-of-sight projection of various components. Some of these regions show evidence of detecting the cavity wall but their location makes the interpretation difficult. In general, the softer plasmas are well fit at temperatures (kT){approx} 0.11 keV, with harder plasmas at temperatures of (kT){approx} 0.27 keV. All regions displayed consistent metal

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

    NASA Technical Reports Server (NTRS)

    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 spectroscophy. 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 10(exp 17)/sq cm at one end to approximately 140 km/s and 8 x 10(exp 17)/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 10(exp 18) 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

  11. An optical and near-infrared exploration of the star formation region in Cygnus surrounding RNO 127

    NASA Astrophysics Data System (ADS)

    Movsessian, T.; Khanzadyan, T.; Magakian, T.; Smith, M. D.; Nikogosian, E.

    2003-12-01

    We investigate a relatively unstudied star formation region in Cygnus centered on RNO 127, finding numerous Herbig-Haro flows, many identified in optical [SII], Hα , and near-infrared H2 tracers of shock waves. Several protostars and young stars are thus located, including one conspicuously brightened object, which illuminates a variable reflection nebula. In total, the coordinates of 17 optical HH knots and jets, 4 associated cometary nebulae and 3 NIR objects are given. Individual structures are discussed including a central complex which has the characteristics of superposed HH flows. This star-forming cloud is not isolated but is part of a much larger region of distributed star formation, including HH 380 and HH 381. Based on observations collected at the Byurakan Astrophysical Observatory, Byurakan, Armenia. Includes observations made at German-Spanish Astronomical Centre, Calar Alto, operated by the Max-Planck-Institut für Astronomie.

  12. Global O VI line emission from the Cygnus Loop supernova remnant and direct kinematic measurement of the associated shock

    NASA Technical Reports Server (NTRS)

    Rasmussen, Andrew; Martin, Christopher

    1992-01-01

    A far-ultraviolet spectrophotometric emission-line mapping of the Cygnus Loop supernova remnant is presented. These are results from the first flight of the rocket-borne, High Resolution Emission Line Spectrometer. The spatial distribution of the emission is that of a limb-brightened shell, and similar to soft X-ray maps. The emission-line profiles, which are broader than the instrument resolution, were consistent with uniformly expanding shell models. Best-fit values give a radial expansion velocity to the emissive region of 185(+/-19) km/s and a reddening-corrected average surface brightness of 8.8(+/-3.6) x 10 exp -6 ergs/sq cm s sr in the doublet. Comparison of the observed brightness with predictions of both radiative and nonradiative shock models provides constraints for the global blast wave ram pressure as well as a "covering factor" of the intermediate velocity shock.

  13. Dipping in CygnusX-2 in a multi-wavelength campaign due to absorption of extended ADC emission

    NASA Astrophysics Data System (ADS)

    Bałucińska-Church, M.; Schulz, N. S.; Wilms, J.; Gibiec, A.; Hanke, M.; Spencer, R. E.; Rushton, A.; Church, M. J.

    2011-06-01

    We report results of one-day simultaneous multiwavelength observations of CygnusX-2 using XMM, Chandra, the European VLBI Network and the XMM Optical Monitor. During the observations, the source did not exhibit Z-track movement, but remained in the vicinity of the soft apex. It was in a radio quiescent/quiet state of <150 μJy. Strong dip events were seen as 25% reductions in X-ray intensity. The use of broadband CCD spectra in combination with narrow-band grating spectra has now demonstrated for the first time that these dipping events in CygnusX-2 are caused by absorption in cool material in quite a unique way. In the band 0.2 - 10 keV, dipping appears to be due to progressive covering of the Comptonized emission of an extended accretion disk corona, the covering factor rising to 40% in deep dipping with an associated column density of 3 × 1023 atom cm-2. Remarkably, the blackbody emission of the neutron star is not affected by these dips, in strong contrast with observations of typical low mass X-ray binary dipping sources. The Chandra and XMM gratings directly measure the optical depths in absorption edges such as Ne K, Fe L, and O K and a comparison of the optical depths in the edges of non-dip and dip data reveals no increase of optical depth during dipping even though the continuum emission sharply decreases. Based on these findings, at orbital phase 0.35, we propose that dipping in this observation is caused by absorption in the outer disk by structures located opposite to the impact bulge of the accretion stream. With an inclination angle >60° these structures can still cover large parts of the extended ADC, without absorbing emission from the central neutral star.

  14. Spatially Resolved Spectroscopy of a Balmer-dominated Shock in the Cygnus Loop: An Extremely Thin Cosmic-Ray Precursor?

    NASA Astrophysics Data System (ADS)

    Katsuda, Satoru; Maeda, Keiichi; Ohira, Yutaka; Yatsu, Yoichi; Mori, Koji; Aoki, Wako; Morihana, Kumiko; Raymond, John C.; Ghavamian, Parviz; Lee, Jae-Joon; Shimoda, Jiro; Yamazaki, Ryo

    2016-03-01

    We present high-resolution long-slit spectroscopy of a Balmer-dominated shock in the northeastern limb of the Cygnus Loop with the Subaru high dispersion spectrograph. By setting the slit angle along the shock normal, we investigate variations of the flux and profile of the Hα line from preshock to postshock regions with a spatial resolution of ˜4 × 1015 cm. The Hα line profile can be represented by a narrow (28.9 ± 0.7 km s-1) Gaussian in a diffuse region ahead of the shock, i.e., a photoionization precursor, and narrow (33.1 ± 0.2 km s-1) plus broad (130-230 km s-1) Gaussians at the shock itself. We find that the width of the narrow component abruptly increases up to 33.1 ± 0.2 km s-1, or 38.8 ± 0.4 km s-1 if we eliminate projected emission originating from the photoionization precursor, in an unresolved thin layer (≲4 × 1015 cm at a distance of 540 pc) at the shock. We show that the sudden broadening can be best explained by heating via damping of Alfvén waves in a thin cosmic-ray (CR) precursor, although other possibilities are not fully ruled out. The thickness of the CR precursor in the Cygnus Loop (a soft gamma-ray emitter) is an order of magnitude thinner than that in Tycho’s Knot g (a hard gamma-ray emitter), which may be caused by the different energy distribution of accelerated particles between the two sources. In this context, systematic studies might reveal a positive correlation between the thickness of the CR precursor and the hardness of the CR energy distribution.

  15. 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.

  16. Discovery of kHz Quasi-periodic Oscillations in the Z Source Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Wijnands, Rudy; Homan, Jeroen; van der Klis, Michiel; Kuulkers, Erik; van Paradijs, Jan; Lewin, Walter H. G.; Lamb, Frederick K.; Psaltis, Dimitrios; Vaughan, Brian

    1998-02-01

    During observations with the Rossi X-Ray Timing Explorer from 1997 June 31 to July 3 we discovered two simultaneous kHz quasi-periodic oscillations (QPOs) near 500 and 860 Hz in the low-mass X-ray binary and Z source Cygnus X-2. In the X-ray color-color diagram and hardness-intensity diagram (HID), a clear Z track was traced out, which shifted in the HID within 1 day to higher count rates at the end of the observation. Z track shifts are well known to occur in Cyg X-2 our observation for the first time catches the source in the act. A single kHz QPO peak was detected at the left end of the horizontal branch (HB) of the Z track, with a frequency of 731+/-20 Hz and an amplitude of 4.7+0.8-0.6% rms in the energy band 5.0-60 keV. Further to the right on the HB, at somewhat higher count rates, an additional peak at 532+/-43 Hz was detected with an rms amplitude of 3.0+1.0-0.7%. When the source moved down the HB, thus when the inferred mass accretion rate increased, the frequency of the higher frequency QPO increased to 839+/-13 Hz, and its amplitude decreased to 3.5+0.4-0.3% rms. The higher frequency QPO was also detected on the upper normal branch (NB) with an rms amplitude of 1.8+0.6-0.4% and a frequency of 1007+/-15 Hz; its peak width did not show a clear correlation with inferred mass accretion rate. The lower frequency QPO was most of the time undetectable, with typical upper limits of 2% rms; no conclusion on how this QPO behaved with mass accretion rate can be drawn. If the peak separation between the QPOs is the neutron star spin frequency (as required in some beat-frequency models), then the neutron star spin period is 2.9+/-0.2 ms (346+/-29 Hz). This discovery makes Cyg X-2 the fourth Z source that displays kHz QPOs. The properties of the kHz QPOs in Cyg X-2 are similar to those of other Z sources. Simultaneous with the kHz QPOs, the well-known horizontal-branch QPOs (HBOs) were visible in the power spectra. At the left end of the HB, the second harmonic of

  17. 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

  18. Surface brightness measurements of supernova remanants in the energy band 0.15 - 4 keV and an XUV survey from an altitude controlled rocket

    NASA Technical Reports Server (NTRS)

    Garmire, G. P.; Riegler, G.

    1973-01-01

    Reports are presented concerning the flight of Aerobee 170, 13.063 UG. The papers presented include: soft X-rays for Cygnus X-1 and Cygnus X-2; X-ray spectrum of the entire Cygnus loop; X-ray surface brightness of the Cygnus loop; and observations of He II 304 A and He I 584 a nightglow.

  19. A cryogenically-cooled, balloon-borne far infrared survey telescope

    NASA Technical Reports Server (NTRS)

    Campbell, M. F.

    1979-01-01

    The design and performance of the Arizona cryogenically-cooled, balloon-borne, multiband far infrared survey telescope are described. The 40 cm Cassegrain telescope is completely contained in a liquid helium dewar. The focal plane array consists of Fabry optics and four detectors which each have a 12 arc minute field of view. Both photoconductive and bolometer detectors are utilized at effective wavelengths of 20, 80, 100 and 150 microns. In 1977 the telescope was used to make multicolor large scale maps of 70 square degrees in the Cygnus X region and the W3 region.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Discovery of Correlated Behavior Between the Hard X-Ray and the Radio Bands in Cygnus X-3

    NASA Technical Reports Server (NTRS)

    McCollough, M. L.; Robinson, C. R.; Zhang, S. N.; Harmon, B. A.; Hjellming, R. M.; Waltman, E. B.; Foster, R. S.; Ghigo, F. D.; Johnston, K. J.

    1998-01-01

    Using CGRO/BATSE hard X-ray data and GHz radio monitoring data from the Green Bank Interferometer (GBI), we have performed a long term study (approximately 1800 days) of the unusual X-ray binary Cygnus X-3 resulting in the discovery of a remarkable relationship between the two wavelength bands. We find that quiescent radio states are strongly anticorrelated with the intensity of the hard X-ray emission. With the onset of a flaring state the relationship switches to a correlation. This is most easily seen in the larger (> or = 1 Jy) flares where the preflare quenched radio emission is accompanied by a very low hard X-ray intensity, and recovery of the hard X-ray flux during the radio flare. The injection of plasma into the radio jets, associated with Cyg X-3, can be directly related to changes in the hard X-ray emission, and suggests the possibility of accretion-related and jet-related components of the high energy emission.

  13. 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

  14. 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.

  15. A Swift/BAT source inside the error circle of the AGILE Cygnus source

    NASA Astrophysics Data System (ADS)

    Ajello, M.; Greiner, J.; Gehrels, G. Kanbach N.

    2008-04-01

    We report on the presence of a Swift/BAT (15-55 keV) source in the error box of the AGILE source (Longo et al. 2008, ATEL #1492) located at l = 78.01 deg, b = 2.19 deg. In the ongoing BAT all-sky survey a source is detected at RA(J2000) = 304.650, Decl.(J2000)= +40.700 (3 arcmin error radius at 90% CL) which is positionally coincident with the INTEGRAL source IGR J20187+4041 (Bykov et al. 2006, ApJ 649, 21).

  16. 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...

  17. 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.

  18. 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.

  19. Surveying Future Surveys

    NASA Astrophysics Data System (ADS)

    Carlstrom, John E.

    2016-06-01

    The now standard model of cosmology has been tested and refined by the analysis of increasingly sensitive, large astronomical surveys, especially with statistically significant millimeter-wave surveys of the cosmic microwave background and optical surveys of the distribution of galaxies. This talk will offer a glimpse of the future, which promises an acceleration of this trend with cosmological information coming from new surveys across the electromagnetic spectrum as well as particles and even gravitational waves.

  20. Low-Energy Line Emission in Cygnus X--2: a Study with ASCA, BBXRT and the Einstein SSS

    NASA Astrophysics Data System (ADS)

    Smale, A. P.; Angelini, L.; White, N. E.; Mitsuda, K.; Dotani, T.

    1994-12-01

    Cygnus X--2 was observed on 1993 June 18--19 for 29 hours using the ASCA GIS and SIS detectors. The observation covered orbital phases phi =0.99--0.12 of the 9.84-day binary cycle (where phi =0.0 is the inferior conjunction of the neutron star). The deadtime-corrected 2--10 keV luminosity of the source is 9times 10(37) ergs s(-1) , and irregular dipping activity is observed with dip durations of order 1000s and depths of 15--20%, superimposed on a smooth longer-term variation of ~ 8%. The dips are not associated with an increase in absorption, and we see no overall correlation between hardness and intensity. This temporal and spectral behavior implies that the source was observed in a interval of relatively stable accretion, probably on the Horizontal Branch of its Z-diagram. The model that best fits the continuum emission consists of a Comptonized component with kTee=1.7 keV and tau =24, plus a blackbody with kTbb=0.6 keV, with the blackbody contributing 12% of the total flux. We observe a strong, low-energy emission feature in the SIS spectrum, which can be modeled using a Gaussian with energy E=1.02+/-0.2 keV, FWHM 325+/-50 eV, and equivalent width EW=60+/-15 eV, but is more likely due to a complex of unresolved Fe L-shell (XVIII-XXIV) lines. Reanalysis of Cyg X--2 data from BBXRT (December 1990; Smale et al. 1993, 410, 796) and the Einstein SSS (June 1979) show that this line emission varies strongly. The BBXRT data show the source on the lower portion of the Normal Branch, with only marginal evidence for E=1 keV emission (EW ~ 10 eV). The SSS data reveal emission at E=1.0 keV with equivalent width 55 eV, plus an additional feature at E=0.78 keV with EW=20 eV. Collating these findings with other archival (Einstein OGS, EXOSAT) results, we find no clear pattern relating the line emission parameters to source spectrum, phase or intensity.

  1. Similar Gamma-Ray Spectral Characteristics of Thermal and Non-Thermal Emission Observed in Cygnus X-1, GROJ0422+32 and GROJ1719-24

    NASA Astrophysics Data System (ADS)

    Ling, J. C.; Wheaton, Wm. A.

    2004-08-01

    BATSE-EBOP (Enhanced BATSE Occultation Package; Ling et al. 2000) gamma-ray (30 keV - 1 MeV) observations of Cygnus X-1, GROJ0422+32 and GROJ1719-24 showed that these sources displayed similar spectral characteristics when undergoing transitions between the high and low gamma-ray intensity states. The high gamma-ray state spectra (gamma-2 , for Cygnus X-1) featured two components: a Comptonized shape below 200-300 keV with a soft power-law tail (photon index > 3) that extended to ˜1 MeV or beyond. For the low gamma-ray state (gamma-0, for Cygnus X-1) spectra, however, the Comptonized spectral shape below 300 keV vanished and the entire spectrum from 30 keV to ˜1 MeV can be characterized by a single power law with a relatively harder photon index ˜2-2.7. The high and low-intensity gamma-ray spectra therefore intersect at ˜400 KeV-1 MeV range, in contrast to the spectral pivoting seen previously at lower ( ˜10 keV) energies. The presence of the power-law component in both the high- and low-intensity gamma-ray spectra strongly suggests that the non-thermal process is likely to be at work in both the high and the low-intensity situations. We have suggested a possible scenario (Ling & Wheaton, 2003,), combining the ADAF model of Esin et al. (1998) with a separate jet region that produces the non-thermal gamma-ray emission, and which explains the state transitions. Such a scenario will be discussed in the context of the observational evidence, summarized above. This work was carried out by the Jet Propulsion Laboratory, under the contract to the National Aeronautics and Space Administration. References: Esin et al., 1998, ApJ, 505, 854. Ling et al.,2000, ApJS , 127, 70. Ling & Wheaton. 2003, ApJ, 584, 399.

  2. High-Resolution Spectroscopy of the X-Ray-photoionized Wind in Cygnus X-3 with the Chandra High-Energy Transmission Grating Spectrometer.

    PubMed

    Paerels; Cottam; Sako; Liedahl; Brinkman; van Der Meer RL; Kaastra; Predehl

    2000-04-20

    We present a preliminary analysis of the 1-10 keV spectrum of the massive X-ray binary Cygnus X-3, obtained with the high-energy transmission grating spectrometer on the Chandra X-Ray Observatory. The source reveals a richly detailed discrete emission spectrum, with clear signatures of photoionization-driven excitation. Among the spectroscopic novelties in the data are the first astrophysical detections of a number of He-like "triplets" (Si, S, Ar) with emission-line ratios characteristic of photoionization equilibrium, fully resolved narrow radiative recombination continua of Mg, Si, and S, the presence of the H-like Fe Balmer series, and a clear detection of an approximately 800 km s-1 large-scale velocity field as well as an approximately 1500 km s-1 FWHM Doppler broadening in the source. We briefly touch on the implications of these findings for the structure of the Wolf-Rayet wind. PMID:10770708

  3. The Physical Interpretation of X-Ray Phase Lags and Coherence: RXTE Observations of Cygnus X-1 as a Case Study

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    There have been a number of recent spectral models that have been successful in reproducing the observed X-ray spectra of galactic black hole candidates (GBHC). However, there still exists controversy over such issues as: what are the sources of hard radiation, what is the system's geometry, is the accretion efficient or inefficient, etc. A potentially powerful tool for distinguishing among these possibilities, made possible by the Rossi X-ray Timing Explorer (RXTE), is the variability data, especially the observed phase lags and variability coherence. These data, in conjunction with spectral modeling, have the potential of determining physical sizes of the system, as well as placing strong constraints on both Compton corona and advection models. As an example, we present RXTE variability data of Cygnus X-1.

  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. 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.

  6. Study of Eclipsing Binary and Multiple Systems in OB Associations. II. The Cygnus OB Region: V443 Cyg, V456 Cyg, and V2107 Cyg

    NASA Astrophysics Data System (ADS)

    Bakış, V.; Hensberge, H.; Bilir, S.; Bakış, H.; 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 ⊙) 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. Timing and Interstellar Scattering of 35 Distant Pulsars Discovered in the PALFA Survey

    NASA Astrophysics Data System (ADS)

    Nice, D. J.; Altiere, E.; Bogdanov, S.; Cordes, J. M.; Farrington, D.; Hessels, J. W. T.; Kaspi, V. M.; Lyne, A. G.; Popa, L.; Ransom, S. M.; Sanpa-arsa, S.; Stappers, B. W.; Wang, Y.; Allen, B.; Bhat, N. D. R.; Brazier, A.; Camilo, F.; Champion, D. J.; Chatterjee, S.; Crawford, F.; Deneva, J. S.; Desvignes, G.; Freire, P. C. C.; Jenet, F. A.; Knispel, B.; Lazarus, P.; Lee, K. J.; van Leeuwen, J.; Lorimer, D. R.; Lynch, R.; McLaughlin, M. A.; Scholz, P.; Siemens, X.; Stairs, I. H.; Stovall, K.; Venkataraman, A.; Zhu, W.

    2013-07-01

    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.

  9. 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.

  10. 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.

  11. Detection of TeV Gamma-Ray Emission from the Cygnus Region of the Galaxy with Milagro Using a New Background Rejection Technique

    SciTech Connect

    Abdo, A. A.

    2006-10-27

    Milagro is a TeV gamma-ray observatory that utilizes a large water Cherenkov detector to observe extensive air showers (EAS) produced by high energy particles impacting the Earth's atmosphere. Milagro's distinct advantage compared to other TeV gamma-ray detectors is that it views a wide field (2 steradian overhead sky) and it continuously operates (> 90% live time ). These factors give Milagro the potential for discovery of new sources with unknown positions and times, such as gamma-ray bursts, flaring AGNs, and observation of diffuse and extended sources like the Galactic plane or large supernova remnants. Here we present a new technique for improving background rejection in Milagro as well as a gamma-ray image of the Cygnus region at energies near 12.5 TeV. We report the detection of both an extended source and a large area of diffuse gamma-ray emission from this region of the galaxy. This new extended source has an extent of 0.32 {+-} 0.12 degrees and an integral flux above 12.5 TeV of (1.71 {+-} 0.24stat {+-} 0.34sys) x 10-13cm-2s-1 assuming a differential source spectrum of E-2.6. The best-fit location for the source is RA = 304.66 {+-} 0.13stat {+-} 0.25sys degrees and declination 36.96 {+-} 0.08stat {+-} 0.2sys degrees.

  12. Western rock lobsters ( Panulirus cygnus) in Western Australian deep coastal ecosystems (35-60 m) are more carnivorous than those in shallow coastal ecosystems

    NASA Astrophysics Data System (ADS)

    Waddington, Kris I.; Bellchambers, Lynda M.; Vanderklift, Mathew A.; Walker, Diana I.

    2008-08-01

    The western rock lobster ( Panurilus cygnus George.) is a conspicuous consumer in the coastal ecosystems of temperate Western Australia. We used stable isotope analysis and gut content analysis to determine the diet and trophic position of western rock lobsters from mid-shelf coastal ecosystems (35-60 m depth) at three locations. Lobsters were primarily carnivorous, and no consistent differences in diet were detected with varying lobster size, sex or among locations. The main components of the diet were bait (from the fishery) and small crustaceans - crabs and amphipods/isopods. Foliose red algae, bivalves/gastropods and sponges were minor contributors to diet. The diet of lobsters in deep coastal ecosystems differed from the results of previous studies of diets of lobsters from shallow coastal ecosystems. In particular, coralline algae and molluscs - important prey in studies of lobsters from shallow coastal ecosystems - were minor components of the diet. These differences are likely to reflect differences in food availability between these systems and potentially, differences in choice of prey by lobsters that inhabit deeper water. Given the high contribution of bait to lobster diet, bait is likely to be subsidizing lobster production in deep coastal ecosystems during the fishing season.

  13. Discovery of a low-frequency broad quasi-periodic oscillation peak in the power density spectrum of Cygnus X-1 with Granat/SIGMA

    NASA Astrophysics Data System (ADS)

    Vikhlinin, A.; Churazov, E.; Gilfanov, M.; Sunyaev, R.; Dyachkov, A.; Khavenson, N.; Kremnev, R.; Sukhanov, K.; Ballet, J.; Laurent, P.; Salotti, L.; Claret, A.; Olive, J. F.; Denis, M.; Mandrou, P.; Roques, J. P.

    1994-03-01

    A transient broad (delta(f)/f = 0.8 approximately 1) very low frequency (approximately 0.04-0.07 Hz) and strong (fractional rms variations are at the level of approximately 10-15% of total source intensity) quasi-periodic oscillations (QPO) feature was discovered by the SIGMA telescope onboard the Granat observatory in the power density spectra of Cygnus X-1; the source was during all the observations carried out in 1990-1992 in its standard (low or hard) spectral state (Sunyaev & Truemper 1979) with average 40-150 keV flux, corresponding appproximately to the 'nominal' gamma2 level of the source (Ling et al. 1979). The power density spectra, obtained in the 4 x 10-4-10 Hz frequency range, typically exhibit strong very low frequency noise below a few millihertz increasing toward lower frequencies, a nearly flat region from a few millihertz up to a break frequency fbr = 0.04 approximately 0.1 Hz and a power-law spectrum as f-1 above the break frequency. The QPO feature, when observed, was centered below or near the break frequency fbr.

  14. 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

  15. 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.

  16. 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.

  17. "Suntelligence" Survey

    MedlinePlus

    ... to the American Academy of Dermatology's "Suntelligence" sun-smart survey. Please answer the following questions to measure ... be able to view a ranking of major cities suntelligence based on residents' responses to this survey. ...

  18. 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…

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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…

  4. Redshift surveys

    NASA Technical Reports Server (NTRS)

    Geller, Margaret J.; Huchra, J. P.

    1991-01-01

    Present-day understanding of the large-scale galaxy distribution is reviewed. The statistics of the CfA redshift survey are briefly discussed. The need for deeper surveys to clarify the issues raised by recent studies of large-scale galactic distribution is addressed.

  5. 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.

  6. SPECTRUM AND MORPHOLOGY OF THE TWO BRIGHTEST MILAGRO SOURCES IN THE CYGNUS REGION: MGRO J2019+37 AND MGRO J2031+41

    SciTech Connect

    Abdo, A. A.; Abeysekara, U.; Linnemann, J. T.; Allen, B. T.; Aune, T.; Berley, D.; Goodman, J. A.; Bonamente, E.; Galbraith-Frew, J. G.; Huentemeyer, P. H.; Hui, C. M.; Christopher, G. E.; Kolterman, B. E.; Mincer, A. I.; DeYoung, T.; Dingus, B. L.; Hoffman, C. M.; Ellsworth, R. W.; Gonzalez, M. M.; McEnery, J. E. E-mail: petra@mtu.edu; and others

    2012-07-10

    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} Multiplication-Sign 10{sup -10} s{sup -1} m{sup -2} TeV{sup -1}, a spectral index of 2.0{sup +0.5}{sub -1.0}, 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} Multiplication-Sign 10{sup -10} s{sup -1} m{sup -2} TeV{sup -1} 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.

  7. Very fast X-ray spectral variability in Cygnus X-1: origin of the hard- and soft-state emission components

    NASA Astrophysics Data System (ADS)

    Skipper, Chris J.; McHardy, Ian M.; Maccarone, Thomas J.

    2013-09-01

    The way in which the X-ray photon index, Γ, varies as a function of count rate is a strong diagnostic of the emission processes and emission geometry around accreting compact objects. Here we present the results from a study using a new, and simple, method designed to improve sensitivity to the measurement of the variability of Γ on very short time-scales. We have measured Γ in ˜2 million spectra, extracted from observations with a variety of different accretion rates and spectral states, on time-scales as short as 16 ms for the high-mass X-ray binary Cygnus X-1 (and in a smaller number of spectra for the low-mass X-ray binary GX 339-4), and have cross-correlated these measurements with the source count rate. In the soft-state cross-correlation functions (CCFs), we find a positive peak at zero lag, stronger and narrower in the softer observations. Assuming that the X-rays are produced by Compton scattering of soft seed photons by high-energy electrons in a corona, these results are consistent with Compton cooling of the corona by seed photons from the inner edge of the accretion disc, the truncation radius of which increases with increasing hardness ratio. The CCFs produced from the hard-state observations, however, show an anti-correlation which is most easily explained by variation in the energy of the electrons in the corona rather than in variation of the seed photon flux. The hard-state CCFs can be decomposed into a narrow anti-correlation at zero lag, which we tentatively associate with the effects of self-Comptonization of cyclo-synchrotron seed photons in either a hot, optically thin accretion flow or the base of the jet, and a second, asymmetric component which we suggest is produced as a consequence of a lag between the soft and hard X-ray emission. The lag may be caused by a radial temperature/energy gradient in the Comptonizing electrons combined with the inward propagation of accretion rate perturbations.

  8. 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.

  9. Initial Data Release of the Kepler-INT Survey

    NASA Astrophysics Data System (ADS)

    Greiss, S.; Steeghs, D.; Gänsicke, B. T.; Martín, E. L.; Groot, P. J.; Irwin, M. J.; González-Solares, E.; Greimel, R.; Knigge, C.; Østensen, R. H.; Verbeek, K.; Drew, J. E.; Drake, J.; Jonker, P. G.; Ripepi, V.; Scaringi, S.; Southworth, J.; Still, M.; Wright, N. J.; Farnhill, H.; van Haaften, L. M.; Shah, S.

    2012-07-01

    This paper describes the first data release of the Kepler-INT Survey (KIS) that covers a 116 deg2 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, Hα, reaching down to a 10σ limit of ~20th mag in the Vega system. Observations covering ~50 deg2, 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_fov/search.php and also via Casjobs at MAST Web site http://mastweb.stsci.edu/kplrcasjobs/).

  10. 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/).

  11. 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.

  12. Drug Survey.

    ERIC Educational Resources Information Center

    Gill, Wanda E.; And Others

    Results of a survey of student perceptions of drugs and drug use that was conducted at Bowie State College are presented. Studies that have been conducted on college students' use of alcohol, marijuana, and cocaine in the last five years are reviewed, along with additional studies relating to the general population and the following drugs:…

  13. 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,…

  14. Multiple Surveys of Students and Survey Fatigue

    ERIC Educational Resources Information Center

    Porter, Stephen R.; Whitcomb, Michael E.; Weitzer, William H.

    2004-01-01

    This chapter reviews the literature on survey fatigue and summarizes a research project that indicates that administering multiple surveys in one academic year can significantly suppress response rates in later surveys. (Contains 4 tables.)

  15. 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.

  16. 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.

  17. 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…

  18. 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.

  19. 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.

  20. 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,…

  1. 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…

  2. Spectral State Dependence of the 0.4-2 MeV Polarized Emission in Cygnus X-1 Seen with INTEGRAL/IBIS, and Links with the AMI Radio Data

    NASA Astrophysics Data System (ADS)

    Rodriguez, Jérôme; Grinberg, Victoria; Laurent, Philippe; Cadolle Bel, Marion; Pottschmidt, Katja; Pooley, Guy; Bodaghee, Arash; Wilms, Jörn; Gouiffès, Christian

    2015-07-01

    Polarization of the ≳ 400 keV hard tail of the microquasar Cygnus X-1 has been independently reported by INTEGRAL/Imager on Board the INTEGRAL Satellite (IBIS), and INTEGRAL/SPectrometer on INTEGRAL and interpreted as emission from a compact jet. These conclusions were, however, based on the accumulation of all INTEGRAL data regardless of the spectral state. We utilize additional INTEGRAL exposure accumulated until 2012 December, and include the AMI/Ryle (15 GHz) radio data in our study. We separate the observations into hard, soft, and intermediate/transitional states and detect radio emission from a compact jet in hard and intermediate states (IS), but not in the soft. The 10-400 keV INTEGRAL (JEM-X and IBIS) state resolved spectra are well modeled with thermal Comptonization and reflection components. We detect a hard tail in the 0.4-2 MeV range for the hard state only. We extract the state dependent polarigrams of Cyg X-1, which are all compatible with no or an undetectable level of polarization except in the 400-2000 keV range in the hard state where the polarization fraction is 75% ± 32% and the polarization angle 40.°0 ± 14.°3. An upper limit on the 0.4-2 MeV soft state polarization fraction is 70%. Due to the short exposure, we obtain no meaningful constraint for the IS. The likely detection of a \\gt 400 keV polarized tail in the hard state, together with the simultaneous presence of a radio jet, reinforce the notion of a compact jet origin of the \\gt 400 keV emission.

  3. 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…

  4. 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 ...

  5. 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.

  6. 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.

  7. PPIC Statewide Survey - Special Survey on Education

    ERIC Educational Resources Information Center

    Baldassare, Mark

    2005-01-01

    The PPIC Statewide Survey series provides policymakers, the media, and the general public with objective, advocacy-free information on the perceptions, opinions, and public policy preferences of California residents. Inaugurated in April 1998, the survey series has generated a database that includes the responses of more than 114,000 Californians.…

  8. 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.

  9. 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…

  10. 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…

  11. 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.

  12. 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)

  13. 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.

  14. Kiso Supernova Survey (KISS): Survey strategy

    NASA Astrophysics Data System (ADS)

    Morokuma, Tomoki; Tominaga, Nozomu; Tanaka, Masaomi; Mori, Kensho; Matsumoto, Emiko; Kikuchi, Yuki; Shibata, Takumi; Sako, Shigeyuki; Aoki, Tsutomu; Doi, Mamoru; Kobayashi, Naoto; Maehara, Hiroyuki; Matsunaga, Noriyuki; Mito, Hiroyuki; Miyata, Takashi; Nakada, Yoshikazu; Soyano, Takao; Tarusawa, Ken'ichi; Miyazaki, Satoshi; Nakata, Fumiaki; Okada, Norio; Sarugaku, Yuki; Richmond, Michael W.; Akitaya, Hiroshi; Aldering, Greg; Arimatsu, Ko; Contreras, Carlos; Horiuchi, Takashi; Hsiao, Eric Y.; Itoh, Ryosuke; Iwata, Ikuru; Kawabata, Koji S.; Kawai, Nobuyuki; Kitagawa, Yutaro; Kokubo, Mitsuru; Kuroda, Daisuke; Mazzali, Paolo; Misawa, Toru; Moritani, Yuki; Morrell, Nidia; Okamoto, Rina; Pavlyuk, Nikolay; Phillips, Mark M.; Pian, Elena; Sahu, Devendra; Saito, Yoshihiko; Sano, Kei; Stritzinger, Maximilian D.; Tachibana, Yutaro; Taddia, Francesco; Takaki, Katsutoshi; Tateuchi, Ken; Tomita, Akihiko; Tsvetkov, Dmitry; Ui, Takahiro; Ukita, Nobuharu; Urata, Yuji; Walker, Emma S.; Yoshii, Taketoshi

    2014-12-01

    The Kiso Supernova Survey (KISS) is a high-cadence optical wide-field supernova (SN) survey. The primary goal of the survey is to catch the very early light of a SN, during the shock breakout phase. Detection of SN shock breakouts combined with multi-band photometry obtained with other facilities would provide detailed physical information on the progenitor stars of SNe. The survey is performed using a 2.2° × 2.2° field-of-view instrument on the 1.05-m Kiso Schmidt telescope, the Kiso Wide Field Camera (KWFC). We take a 3-min exposure in g-band once every hour in our survey, reaching magnitude g ˜ 20-21. About 100 nights of telescope time per year have been spent on the survey since 2012 April. The number of the shock breakout detections is estimated to be of the order of 1 during our three-year project. This paper summarizes the KISS project including the KWFC observing setup, the survey strategy, the data reduction system, and CBET-reported SNe discovered so far by KISS.

  15. Optical & NIR Transient Surveys

    NASA Astrophysics Data System (ADS)

    Cross, Nicholas J. G.; Djorgovski, S. G.

    2012-04-01

    A workshop on Optical & Near Infrared Transients took place during the first afternoon of the Symposium. It ran for two sessions. The first was given over to talks about various current optical and near-infrared transient surveys, focussing on the Vista surveys, the Catalina Real-Time Transient Survey, Pan-STARRS, Gaia, TAOS and TAOS2. The second session was a panel-led discussion about coordinating multi-wavelength surveys and associated follow-ups.

  16. DEMOGRAPHIC AND HEALTH SURVEYS

    EPA Science Inventory

    Demographic and Health Surveys are nationally representative household surveys with large sample sizes of between 5,000 and 30,000 households, typically. DHS surveys provide data for a wide range of monitoring and impact evaluation indicators in the areas of population, health, a...

  17. 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…

  18. Campus Climate Survey.

    ERIC Educational Resources Information Center

    Mattice, Nancy J.

    A survey was conducted at College of the Canyons (COC) to assess the current status of the campus climate. The survey instrument focused on students' experiences, attitudes about diversity issues, and suggestions for improving the climate for diversity. The survey was mailed to all disabled and under-represented racial/ethnic group students plus a…

  19. NATIONAL SURVEY OF MEN

    EPA Science Inventory

    The 1991 National Survey of Men was conducted to examine issues related to sexual behavior and condom use among U.S. men aged 20 to 39. Data collection and processing took place between March 1991 and January 1992. This survey was intended to serve as a baseline survey for a long...

  20. The Introductory Sociology Survey

    ERIC Educational Resources Information Center

    Best, Joel

    1977-01-01

    The Introductory Sociology Survey (ISS) is designed to teach introductory students basic skills in developing causal arguments and in using a computerized statistical package to analyze survey data. Students are given codebooks for survey data and asked to write a brief paper predicting the relationship between at least two variables. (Author)

  1. 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…

  2. MALAYSIAN FAMILY LIFE SURVEY

    EPA Science Inventory

    The Malaysian Family Life Surveys (MFLS) comprise a pair of surveys with partially overlapping samples, designed by RAND and administered in Peninsular Malaysia in 1976-77 (MFLS-1) and 1988-89 (MFLS-2). Each survey collected detailed current and retrospective information on famil...

  3. 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.

  4. Nova Survey participation requested

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2013-03-01

    The AAVSO solicits participation in an online nova survey from our member and observer communities. The survey is being conducted in advance of an upcoming long-term observing campaign that will be launched in mid-April 2013. We are seeking participation in this survey from as broad a sample of the AAVSO community as possible, and your responses will help us gauge the effectiveness of the campaign and serve the observer community better. The survey may be completed anonymously, but you will have the option of providing us with your name and AAVSO observer code if you choose. Please visit the following website to complete the survey: https://www.surveymonkey.com/s/ZQHDYWB. The survey should take no more than five minutes to complete. We ask that you complete the survey by Monday, April 15, 2013.

  5. 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. PMID:18940417

  6. 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

  7. Digitised optical sky surveys.

    NASA Astrophysics Data System (ADS)

    MacGillivray, H. T.

    1990-12-01

    Contents: 1. The Second Palomar Observatory Sky Survey. 2. The status of the UKST surveys. 3. A proposal for the construction of a 150/220-cm Schmidt Telescope and processing facilities in China. 4. The measuring machines - a world roundup. 5. Reports from the individual machine groups. 6. A progress report on the APS catalog of POSS I. 7. The ROE/NRL collaborative effort on the COSMOS/UKST survey material. 8. Automated optical identification of IRAS Faint Source Survey Objects. 9. A catalogue of the North Galactic Pole. 10. The need for standard data sets. 11. Programmes on plate calibration. 12. Automated image measuring system. 13. Astronomical image data compression. 14. Opportunities for image compression in astronomy. 15. The Loiano 152 cm telescope CCD images archive. 16. PPM: a reference star catalogue for sky surveys. 17. Announcement: Second Meeting on Digitised Optical Sky Surveys.

  8. 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.

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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,…

  14. 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…

  15. 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,…

  16. Ye Olde Maile Surveye.

    ERIC Educational Resources Information Center

    Berty, Ernest

    This publication is primarily designed for educational practitioners who possess little or no training in conducting mail surveys or have not kept current on the present state of the art of survey methods and techniques. It is also intended to be a checking and comparing aid to ensure that important research considerations are taken into account.…

  17. Westchester County Employers Survey.

    ERIC Educational Resources Information Center

    Lee, Marcia M.

    The Westchester County Employers Survey was done in May 2003 in order learn more about employee training needs, how they accomplished these needs, and how it would be possible for the Westchester Community College to fulfill these needs. Out of the 639 surveys sent, 145 were returned in a satisfactory format, which produces a 22.6% return rate.…

  18. 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…

  19. NATIONAL COMORBIDITY SURVEY (NCS)

    EPA Science Inventory

    The National Comorbidity Survey (NCS) was a collaborative epidemiologic investigation designed to study the prevalence and correlates of DSM III-R disorders and patterns and correlates of service utilization for these disorders. The NCS was the first survey to administer a struct...

  20. Ohio Business Surveys.

    ERIC Educational Resources Information Center

    Baughin, Judith A.

    Results of four surveys of international businesses in the Toledo, Columbus, Cincinnati, and Akron, Ohio, areas regarding the language skills of employees and usefulness of second language skills in their domestic and international trade activities are reported in detail. In the Toledo survey it was found that of the 48 respondents, 72% responded…

  1. Career Development Survey.

    ERIC Educational Resources Information Center

    Mulley, Barbara W.; And Others

    Based on a 1992 survey of 146 child care centers, this report documents the current wages and turnover rates for early child care staff in the St. Louis metropolitan area. The survey was designed to collect descriptive information about the population of individuals working in child care and early education and to provide baseline data to assess…

  2. 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…

  3. 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)…

  4. 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…

  5. 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.

  6. 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…

  7. 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…

  8. How To Design Surveys. The Survey Kit, Volume 5.

    ERIC Educational Resources Information Center

    Fink, Arlene

    The nine-volume Survey Kit is designed to help readers prepare and conduct surveys and become better users of survey results. All the books in the series contain instructional objectives, exercises and answers, examples of surveys in use, illustrations of survey questions, guidelines for action, checklists of "dos and don'ts," and annotated…

  9. 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.

  10. Extragalactic HI surveys

    NASA Astrophysics Data System (ADS)

    Giovanelli, Riccardo; Haynes, Martha P.

    2015-12-01

    We review the results of HI line surveys of extragalactic sources in the local Universe. In the last two decades major efforts have been made in establishing on firm statistical grounds the properties of the HI source population, the two most prominent being the HI Parkes All Sky Survey and the Arecibo Legacy Fast ALFA survey. We review the choices of technical parameters in the design and optimization of spectro-photometric "blind" HI surveys, which for the first time produced extensive HI-selected data sets. Particular attention is given to the relationship between optical and HI populations, the differences in their clustering properties and the importance of HI-selected samples in contributing to the understanding of apparent conflicts between observation and theory on the abundance of low mass halos. The last section of this paper provides an overview of currently ongoing and planned surveys which will explore the cosmic evolution of properties of the HI population.

  11. Surveying young patients.

    PubMed

    Foster, Theresa; Maillardet, Victoria

    2010-03-01

    The East of England Ambulance Service NHS Trust (the Trust) was keen to engage young patients and to encourage them to give feedback about the service they had received. The standard Trust satisfaction survey was modified for use with young patients, and this had the effect of increasing the response rate from this patient group by 8%, and increasing the percentage of young patients aged 5-10 years completing the survey themselves by 29%. The vast majority of parents/guardians were happy for the Trust to survey their child, but the age of the child affected to whom they would like the survey sent. The Trust subsequently altered patient survey practice to write to parents/guardians of patients aged <12 years and directly to all patients aged > or = 12 years. PMID:20304894

  12. 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.

  13. 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.

  14. 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.

  15. 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)

  16. PROTECTING CONFIDENTIALITY IN ESTABLISHMENT SURVEYS

    EPA Science Inventory

    This invited chapter for an International Monograph on Survey Methods inEstablishment Surveys summarizes methods for protecting respondent confidentiality in establishment surveys and includes open research problems and an extensive bibliography. t will be summarized in an invite...

  17. Advanced camera for surveys

    NASA Astrophysics Data System (ADS)

    Clampin, Mark; Ford, Holland C.; Bartko, Frank; Bely, Pierre Y.; Broadhurst, Tom; Burrows, Christopher J.; Cheng, Edward S.; Crocker, James H.; Franx, Marijn; Feldman, Paul D.; Golimowski, David A.; Hartig, George F.; Illingworth, Garth; Kimble, Randy A.; Lesser, Michael P.; Miley, George H.; Postman, Marc; Rafal, Marc D.; Rosati, Piero; Sparks, William B.; Tsvetanov, Zlatan; White, Richard L.; Sullivan, Pamela; Volmer, Paul; LaJeunesse, Tom

    2000-07-01

    The Advanced Camera for Surveys (ACS) is a third generation instrument for the Hubble Space Telescope (HST). It is currently planned for installation in HST during the fourth servicing mission in Summer 2001. The ACS will have three cameras.

  18. 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.

  19. 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.

  20. NATIONAL IMMUNIZATION SURVEY (NIS)

    EPA Science Inventory

    The National Immunization Survey (NIS) is sponsored by the National Immunization Program (NIP) and conducted by the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention.

  1. Low Frequency Sky Surveys

    NASA Astrophysics Data System (ADS)

    Lubin, Philip M.

    2015-08-01

    We propose to survey the sky from 10-100 GHz covering greater than 50% of the sky in intensity and polarizatiton. This will allow us to mep out the synchrotron and free - free background as well as the spinning dust component to sufficient sensitivity to allow detailed modeling and removal of the galactic foregrounds allowing for deeper polarization surveys searching for signatures of inflation. While most measurements have concentrated on the region above 100 GHz this reggion is more complex in dust contmination that originally thought. Dust is best measured at high frequencies but the atmosphere greatly hinders extremely deep dust surveys due to water vapor. Surveys ar low frequency will be complimentary to the higher frequency measurements.

  2. Flat conductor cable survey

    NASA Technical Reports Server (NTRS)

    Swanson, C. R.; Walker, G. L.

    1973-01-01

    Design handbook contains data and illustrations concerned with commercial and Government flat-conductor-cable connecting and terminating hardware. Material was obtained from a NASA-sponsored industry-wide survey of approximately 150 companies and Government agencies.

  3. AMERICAN HOUSING SURVEY

    EPA Science Inventory

    The American Housing Survey (AHS) collects data on the Nation's housing, including apartments, single-family homes, mobile homes, vacant housing units, household characteristics, income, housing and neighborhood quality, housing costs, equipment and fuels, size of housing unit, a...

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. NATIONAL NURSING HOME SURVEY (NNHS)

    EPA Science Inventory

    The National Nursing Home Survey (NNHS) is a continuing series of national sample surveys of nursing homes, their residents, and their staff.The survey was conducted in 1973-74, 1977, 1985, 1995, 1997, and 1999. Although each of these surveys emphasized different topics, they all...

  10. Views About Sciences Survey: VASS.

    ERIC Educational Resources Information Center

    Halloun, Ibrahim; Hestenes, David

    The Views About Sciences Survey (VASS) is a survey of student views about science for the purpose of assessing the influence of these views on learning. This paper discusses the survey's design, development, results, and implications for science education. The survey assesses student views along seven dimensions with a novel Contrasting…

  11. 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.

  12. 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.

  13. 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. .

  14. The Dark Energy Survey

    SciTech Connect

    Flaugher, Brenna; /Fermilab

    2004-11-01

    Dark Energy is the dominant constituent of the universe and they have little understanding of it. They describe a new project aimed at measuring the dark energy equation of state parameter, w, to a statistical precision of {approx} 5%, with four separate techniques. The survey will image 5000 deg{sup 2} in the southern sky and collect 300 million galaxies, 30,000 galaxy clusters, and 2000 Type Ia supernovae. The survey will be carried out using a new 3 deg{sup 2} mosaic camera mounted at the prime focus of the 4m Blanco telescope at CTIO.

  15. 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.

  16. 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.

  17. Survey of Study Programs.

    ERIC Educational Resources Information Center

    Ellis, E. N.; Moodie, Allan G.

    This appendix contains the questionnaire, Survey of Study Programs, which was sent to the principals of the Vancouver secondary schools to determine what opportunities were provided for students to study independently. The thirteen questions are in short answer and "Yes/No" form. There is room available for comment. (See TM 000 969.) (MS)

  18. 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…

  19. 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…

  20. Surveying School Facilities Needs.

    ERIC Educational Resources Information Center

    Weichel, Harry J.; Dennell, James

    1990-01-01

    Ralston (Nebraska) Public School District's communitywide survey helped set school facilities priorities while keeping the district's finite resources firmly in mind. With an outline of maintenance costs for the next 10 years, the district can develop a strategic construction schedule. The board also has the option of financing projects through a…

  1. MARYLAND BIOLOGICAL STREAM SURVEY

    EPA Science Inventory

    The Maryland Biological Stream Survey (MBSS) is a multi-year probability-based sampling program designed to assess the status of biological resources in non-tidal streams of Maryland. The MBSS is quantifying the extent to which acidic deposition and other human activities have af...

  2. Freshmen Survey, Fall 1984.

    ERIC Educational Resources Information Center

    Allen, David F.

    A model to distinguish persisters and nonpersisters at the University of North Carolina, Wilmington, was developed. Persisters and nonpersisters differed in background characteristics, attitudes toward and interaction with the university, opportunities to leave, and intentions. Responses to a mail survey were returned by 86 first-time freshmen…

  3. 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.…

  4. The Equity Survey.

    ERIC Educational Resources Information Center

    Council of Ontario Universities, Toronto.

    In August 2001, applicants to Ontario, Canada, universities received a survey from the Council of Ontario Universities to better understand the socioeconomic status and representation of members of recognized designated groups (Aboriginal Peoples of Canada, members of visible minority groups, people with disabilities, and women) in the university…

  5. NATIONAL ALCOHOL SURVEY (NAS)

    EPA Science Inventory

    National Alcohol Survey (NAS) is designed to assess the trends in drinking practices and problems in the national population, including attitudes, norms, treatment and experiences and adverse consequences. It also studies the effects of public policy on drinking practices (i.e., ...

  6. 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…

  7. Salary Survey Results. 1987.

    ERIC Educational Resources Information Center

    Cassell, Marianne K.

    Based on a survey conducted by the Vermont Department of Libraries during the summer of 1987, this document reports the salaries paid library directors, librarians holding M.L.S. degrees, and support and custodial staff members in the state's libraries. Questionnaires were sent to all the public, academic, special, institutional, and school…

  8. 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.

  9. 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…

  10. 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…

  11. Library Awareness Survey.

    ERIC Educational Resources Information Center

    Rice, James

    1992-01-01

    Reports results of a survey of Iowa City residents regarding their awareness of public library services. Data are presented on use of the library for factual information, statistical/numerical information, learning, and information not available at home; awareness of in-person and telephone library reference services; and knowledge about…

  12. 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…

  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. 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,…

  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. 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)

  17. Survey of Gait Recognition

    NASA Astrophysics Data System (ADS)

    Liu, Ling-Feng; Jia, Wei; Zhu, Yi-Hai

    Gait recognition, the process of identifying an individual by his /her walking style, is a relatively new research area. It has been receiving wide attention in the computer vision community. In this paper, a comprehensive survey of video based gait recognition approaches is presented. And the research challenges and future directions of the gait recognition are also discussed.

  18. Surveys, Sophomores, and Shoestrings

    ERIC Educational Resources Information Center

    Falco, Maria J.

    1973-01-01

    A program at Le Moyne which involved undergraduate students in a professional type social science empirical research project is described in this article. Information is given on how students conducted a survey to measure the existence of polarization within the general population, and between college students and the general population;…

  19. Eleventh Annual Salary Survey.

    ERIC Educational Resources Information Center

    Philadelphia Suburban School Study Council, PA.

    This survey provides current data for school directors and administrators to examine the policies of compensation for professional personnel in the suburban Philadelphia area. The report contains three sections: a) salaries of teachers, b) salaries of instructional specialists, and c) salaries of administrative and supervisory personnel. Mean…

  20. 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…

  1. 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…

  2. 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…

  3. Humboldt County Employer Survey.

    ERIC Educational Resources Information Center

    Lyons, Dave

    A project was undertaken in Humboldt County to collect information from large and small businesses in the areas of agriculture, mining, manufacturing, transportation, wholesale and retail, finance, services, and public information with respect to their employee requirements and needs. In all, 451 firms were surveyed to determine the size of the…

  4. 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;…

  5. Urban Rat Surveys.

    ERIC Educational Resources Information Center

    Littig, K. S.; And Others

    This guide is for use in the classroom and field training of inspection and operational personnel who serve in planned community rodent-control programs. The urban rat survey may be used as the primary means of obtaining information on rat infestations and the conditions favoring rat populations in urban communities. It provides the data necessary…

  6. GPR survey in industrial archaeology survey

    NASA Astrophysics Data System (ADS)

    Vendrell, D.; Pérez Gracia, V.; González Drigo, R.

    2003-04-01

    A preliminary GPR (Ground Penetrating Radar) study was performed at the Escola Tècnica Industrial de Barcelona (Industrial University of Barcelona) in order to detect structures and cavities under the ground of one of their buildings. In the 19th century, at the present university campus, was located an ancient textile factory. This factory was founded by the Batlló family and has becomed one of the most important examples of catalan modernist industrial architecture in Barcelona. At the beginning of the last century, it was donated to the city by its former owners to be used as a school. In order to turn out the factory into a scholastic centre, many changes were undertaken, so many pipes and tubes were covered with a new pavement and some underground tunnels were blocked. The purpose of this research is to locate these ancient structures and assess its uses. Datum obtained with the ground-penetrating radar has been compared with the information found in the historical archives of the Diputació de Barcelona (most of it were pictures that show the layout of the ancient machinery in some rooms of the factory). Since the contents of these files are not accurate nor complete, GPR survey has provided new information not only about what is underneath the soil of the building analyzed, but also its condition and characteristics.

  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. 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

  9. 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

  10. 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

  11. 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…

  12. 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…

  13. LBA Calibrator Survey

    NASA Astrophysics Data System (ADS)

    Phillips, Chris; Petrov, Leonid; Bertarini, Alessandra

    2009-07-01

    The Australian LBA (Long Baseline Array) has been used to observe a list of candidate flat spectrum radio sources with declination < -50° to determine their position with milliarcsec accuracy and determine their suitability as calibrators for phase referencing observations and as target for astrometry and geodesy observations. Currently more than 316 new millisecond positions have been determined with a final goal of around 1000 astrometric positions for a high density phase reference grid. The candidate list is based on the AT20G survey, an all-sky 20 GHz survey using an 8 GHz analog correlator for the ATCA. So far a detection rate of candidate source of 97% has been achieved.

  14. Well surveying instrument sensor

    SciTech Connect

    Poquette, R.S.

    1981-01-20

    A surveying instrument sensor which includes a gimbal supported for rotation within a casing, a torquer coupled to rotate the gimbal with a first two-axis flexure suspended gyro supported on the gimbal with its spin axis perpendicular to the axis of the gimbal and one of its sensitive axes aligned with the axis of the gimbal, a second two-axis flexure suspended gyro disposed on the gimbal with its spin axis alinged with the axis of the gimbal and having two sensitive axes outputs orthogonal thereto. The output of the first gyro is coupled to the torquer to form a gimbal stabilized loop and the outputs and torquing inputs of the second gimbal coupled into rate capture loops with output signals obtained from the rate captured loops permitting fast and accurate surveying of a well pipe.

  15. 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.

  16. 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.

  17. 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.

  18. Global risks survey

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-01-01

    The top five risks facing the globe over the next decade, in order of the likelihood of their occurring, are severe income disparity, chronic fiscal imbalance, rising greenhouse gas emissions, water supply crises, and the mismanagement of population aging. That is according to a survey of more than 1000 experts from industry, government, academia, and civil society, presented in the World Economic Forum's Global Risks 2013 report that was issued on 8 January.

  19. 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

  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. 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.

  2. 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.

  3. 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).

  4. HST Cluster Supernova Survey

    NASA Astrophysics Data System (ADS)

    Suzuki, Nao; Aldering, G.; Amanullah, R.; Barbary, K.; Barrientos, L.; Brodwin, M.; Connolly, N.; Dawson, K.; de Jong, R.; Dey, A.; Doi, M.; Donahue, M.; Eisenhardt, P.; Ellingson, E.; Faccioli, L.; Fadeyev, V.; Fakhouri, H.; Fruchter, A.; Gilbank, D.; Gladders, M.; Goldhaber, G.; Gonzalez, A.; Goobar, A.; Gude, A.; Hennawi, J.; Hoekstra, H.; Hsiao, E.; Huang, X.; Ihara, Y.; Jannuzi, B.; Jee, M. J.; Koester, B.; Kowalski, M.; Lidman, C.; Linder, E.; Lubin, L.; Morokuma, T.; Perlmutter, S.; Postman, M.; Rhodes, J.; Rosati, P.; Ripoche, P.; Rubin, D.; Schlegel, D.; Spadafora, A.; Stanford, A.; Stern, D.; Yasuda, N.; Yee, H.; Cosmology Project, Supernova

    2010-01-01

    We report results from the Hubble Space Telescope (HST) Cluster Supernova Survey with the Advanced Camera for Surveys (ACS) (PI: Perlmutter; see Dawson et al. AJ, 2009). We have introduced a novel approach to discover and follow Type Ia supernovae (SNeIa). With HST, we monitored 25 massive clusters (0.9 < z < 1.4) found by the RCS, XMM, IRAC, and RDCS surveys and conducted spectroscopic observations with the Keck, Subaru, and VLT telescopes. Sixteen SNe were discovered at 0.95 < z < 1.41, nine of which were in galaxy clusters (for a discussion of the rates, see K. Barbary, oral presentation at this meeting). The SNe in galaxy clusters are found primarily in early type galaxies in the cluster red-sequence that have been shown to be nearly dust-free and uniform populations (see poster presentation by Meyers et al.). The reduction and control of systematic error is an urgent task for the study of dark energy today (see Rubin et al. poster presentation), and we discuss how this unique SNe Ia data set reduces both statistical and more importantly systematic uncertainty at the highest redshifts. This work has been supported by the Office of Science, U.S. Department of Energy, through contract DE-AC02-05CH11231 and in part by NASA through grants associated with HST-GO-10496.

  5. Survey report: Colombia.

    PubMed

    Marquette, C M

    1988-03-01

    The preliminary results of the 1986 Colombian Demographic and Health Survey (DHS) of 4480 households -- 5329 individual interviews of women ranging in age from 15-49 years -- suggested a decline in the total fertility rate (TFR) by 1.4 during the last 10 years, from 4.8 to 3.4. Contraceptive use increased 2 percentage points between 1976-86, from 43% to 63% of currently married women. Current use of contraception varied according to age: 58% of women under 30 and 67% of women over 30 used contraception. There also were differentials according to parity: 57% of women with 0-2 children, 75% of women with 3-4 children, and 61% of women with 5 or more children used some contraceptive method. 53% of rural and 68% of urban women used contraception. The 1986 survey findings suggest that female sterilization may have replaced oral contraceptive (OC) use as the preferred method. Of the 63% of all women surveyed currently using some method, 18% adopted sterilization, 17% OC, and 10% the IUD. 70% of married women interviewed wanted no more children. 31% of women who indicated they wanted no more children were not using contraception, a decline from the 50% unmet need reported in 1976. PMID:12341835

  6. MEDICAL EXPENDITURE PANEL SURVEY (MEPS)

    EPA Science Inventory

    The Medical Expenditure Panel Survey, or MEPS as it is commonly called, is the third (and most recent) in a series of national probability surveys conducted by AHRQ on the financing and utilization of medical care in the United States.

  7. DRINKING WATER INFRASTRUCTURE NEEDS SURVEY

    EPA Science Inventory

    Conducted every 4 years, the Drinking Water Infrastructure Needs Survey (DWINS) is an EPA-conducted statistically-based survey of the infrastructure investment needs of the Nation's drinking water systems for the next 20 years.

  8. 77 FR 19032 - Geological Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-29

    ... Geological Survey Announcement of National Geospatial Advisory Committee Meeting AGENCY: U.S. Geological Survey, Interior. ACTION: Notice of meeting. SUMMARY: The National Geospatial Advisory Committee (NGAC... advance. Please register by contacting Arista Maher at the U.S. Geological Survey (703-648-6283,...

  9. New Student Survey, Fall 1998.

    ERIC Educational Resources Information Center

    Weglarz, Shirley

    The Fall 1998 annual survey of new Johnson County Community College (JCCC) students was designed to determine new students' educational objectives and what factors influence new students' decisions to attend JCCC. Surveys mailed to 3874 students identified by the Admissions Office resulted in 713 usable returned surveys. This evaluation reports…

  10. 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…

  11. DRUG SERVICE RESEARCH SURVEY (DSRS)

    EPA Science Inventory

    The Drug Services Research Survey (DSRS) is a national survey which obtained information on drug treatment providers and clients in 1990. The survey consisted of several components, a facility-based telephone interview with a sample of 1,183 drug treatment providers followed by a...

  12. 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…

  13. NATIONAL PREGNANCY AND HEALTH SURVEY

    EPA Science Inventory

    The National Pregnancy and Health Survey conducted by NIDA is a nationwide hospital survey to determine the extent of drug abuse among pregnant women in the United States. The primary objective of the National Pregnancy and Health Survey (NPHS) was to produce national annual esti...

  14. NATIONAL MORTALITY FOLLOWBACK SURVEY (NMFS)

    EPA Science Inventory

    The 1993 National Mortality Followback Survey (NMFS) is the latest in a series of periodic surveys designed to supplement information routinely collected on the death certificate. The Mortality Followback Survey Program, begun in the 1960's by the National Center for Health Stati...

  15. 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…

  16. 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

  17. 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

  18. FAME Radial Velocity Survey

    NASA Astrophysics Data System (ADS)

    Salim, S.; Gould, A.

    2000-12-01

    Full-Sky Astrometric Mapping Explorer (FAME) belongs to a new generation of astrometry satellites and will probe the surrounding space some 20 times deeper than its predecessor Hipparcos. As a result we will acquire precise knowledge of 5 out of 6 components of phase-space for millions of stars. The remaining coordinate, radial velocity, will remain unknown. In this study, we look at how the knowledge of radial velocity affects the determination of the structure of the Galaxy, and its gravitational potential. We therefore propose a radial velocity survey of FAME stars, and discuss its feasibility and technical requirements.

  19. Thermionic deposition devices (survey)

    SciTech Connect

    Saenko, V.A.

    1985-11-01

    Various devices for the deposition of thin films and coatings from a plasma of solid-phase-material vapor are surveyed. The devices operate by vaporization and ionization of the working material in a vacuum. The classification, parameters, designs and development trends of thermionic devices (plasma vaporizers) are examined. Their characteristics and areas of application in modern high-energy plasma technology are described. The relative simplicity of the design and operation of the devices should allow them to be widely used not only in the laboratory but also in industry. The first manufactured units with thermionic devices and some of the properties of the films they produce are described.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Bolivia survey reveals disparities.

    PubMed

    1999-01-01

    Findings from the Bolivia Demographic and Health Survey in 1998 indicate that large fertility and reproductive health disparities based on education level and geographic location still persist in the country. Despite substantial improvement in the overall education level of Bolivian women in the past 5 years, urban women are almost 5 times more likely to attend high school than rural women are. Major differences in education level also exist between provinces. Total fertility rate is at 4.2 children per woman, with women without education having more than 3 times the number of children compared to those with higher education. At such rates, rural women will have an average of 6.3 children, which are 2.5 children more than their urban counterparts. Moreover, nearly 80% of women in union know of a modern method of contraception and 45% of them are using some form of family planning. The highest levels of contraceptive use are among women with higher education and women in urban areas. There is also a notable increase in the number of women who receive assistance from a trained medical professional during delivery. Infant and child mortality rates remain among the highest in Latin America although both rates have declined since the 1994 survey findings. Infant mortality rates are still 80% higher in rural areas than urban areas. PMID:12349605

  5. Dragline noise survey

    NASA Astrophysics Data System (ADS)

    Vipperman, Jeffrey S.; Bauer, Eric R.

    2002-05-01

    It is estimated that 70%-90% of miners have enough noise induced hearing loss (NIHL) to be classified as a disability (NIOSH, Publication No. 76-172, 1976; Franks, NIOSH Internal Report, 1996). In response, NIOSH is conducting a cross-sectional survey of the mining industry in order to determine the sources of mining noise and offer recommendations on how to mitigate high noise levels, and bring mining operations into compliance with the recent mining noise regulation: 30CFR, Part 62. This paper will outline the results from noise surveys of eight draglines which operate in above-ground coal mining operations. The data recorded include noise dosimetry in conjunction with time-at-task studies and 1/3-octave sound level (Leq, Lmin, and Lmax) measurements. The 1/3-octave band readings were used to create noise contour maps which allowed the spatial and frequency information of the noise to be considered. Comparison of Lmin and Lmax levels offer insight into the variability of the noise levels inside the dragline. The potential for administrative controls is limited due to consistently high noise levels throughout the deck. Implementation of engineering controls is also hindered by the size and number of the noise sources and the frequency content of the noise.

  6. Borehole survey instrument

    SciTech Connect

    Sharp, H.E.; Lin, J.W. III; Macha, E.S.; Smither, M.A.

    1984-12-04

    A borehole survey instrument is provided having a meniscus type floating compass member with indicia thereon for indicating azimuth and inclination. A light source is disposed below the indicia for illuminating the indicia upward through the liquid through which the meniscus type floating compass member floats. A lens system is provided for focusing the image of the illuminated compass member upon a film disposed below the compass member. This arrangement permits the centering post for the compass member to be of minimum diameter consistent with rigidity requirements and permits a high angle compass member to indicate angles of inclination approaching ninety degrees. A multiple light bulb light source is utilized and each light bulb is mounted in a manner which permits a single light bulb to illuminate the entire compass member. A hand-held programming and diagnostic unit is provided which may be momentarily electrically mated with the borehole survey tool to input a programmed timed delay and diagnostically test both the condition of the light bulbs utilized as the illumination source and the state of the batteries within the instrument. This hand-held programmable unit eliminates all the mechanical programming switches and permits the instrument to be completely sealed from the pressure, fluids and contaminants normally found in a well bore.

  7. 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.

  8. 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... Validation survey. (a) Basis for survey. CMS may require a survey of an accredited provider or supplier to.... (b) Effect of selection for survey. A provider or supplier selected for a validation survey must—...

  9. 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... Validation survey. (a) Basis for survey. CMS may require a survey of an accredited provider or supplier to.... (b) Effect of selection for survey. A provider or supplier selected for a validation survey must—...

  10. 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.

  11. 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.

  12. And the Survey Says…

    NASA Astrophysics Data System (ADS)

    White, Susan C.

    2016-02-01

    Every four years we survey a nationally representative sample of high school physics teachers. We define anyone who teaches at least one physics class to be a "physics teacher." About 40% of these teachers teach a majority of their classes in subjects other than physics. We also ask teachers to rate how well prepared they felt in various aspects of teaching. The response choices are "not adequately prepared," "adequately prepared," and "very well prepared." The accompanying figure shows the proportion of teachers who reported feeling adequately or very well prepared in the following aspects of teaching: • Basic physics knowledge, • Other science knowledge, • Application of physics to everyday experience, • Use of demonstrations, • Instructional laboratory design, • Use of computers in physics instruction and labs, and • Recent developments in physics.

  13. 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.

  14. Hunger: a hospital survey.

    PubMed

    Rosenberg, E; Bernabo, L

    1992-01-01

    Patients at a New York City municipal hospital were surveyed in 1985 and 1989 to ascertain the extent of hunger and its possible correlates. Twenty-two percent (22%) of the 382 subjects in 1985 and 23% of the 332 subjects in 1989 experienced hunger. Hunger was related significantly to homelessness, social isolation and the physical inability to buy and/or prepare food. Between 1985 and 1989, there was a large increase in the use of institutional resources for food; a decline in reliance on Food Stamps; and an increase in household density. Inpatients were found to be poorer than outpatients, and to rely more heavily upon soup kitchens. Practice, policy and research implications are noted. PMID:1589827

  15. 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.

  16. The Scarborough Glaucoma Survey

    PubMed Central

    Shenken, Ellis; Glas, S.

    1966-01-01

    A glaucoma screening survey was carried out in Scarborough, Ontario, to detect previously unsuspected cases of the disease. General practitioners were employed to perform Schiotz tonometry. Suspected cases were further tested with applanation tonometry and tonography with water drinking. Of the 17,968 persons examined, 999 had a family history of glaucoma. Forty-one of these had obvious clinical glaucoma. The use of Schiotz tonometry plus applanation tonometry in individuals with a positive family history uncovered 463 suspected of having glaucoma. Tonography with water drinking revealed 348 persons with abnormal findings. Of this number, 228 had clinical glaucoma and 120 preclinical glaucoma. Mass screening by tonometry was found to be valuable in detecting glaucoma in the early stages. In most instances, blindness from this disease can be prevented by early diagnosis. ImagesFig. 1Fig. 2Fig. 3 PMID:5912178

  17. 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.

  18. Ninth Triennial Toxicology Salary Survey.

    PubMed

    Gad, Shayne Cox; Sullivan, Dexter Wayne

    2016-03-01

    This survey serves as the ninth in a series of toxicology salary surveys conducted at 3-year intervals and beginning in 1988. An electronic survey instrument was distributed to 5919 individuals including members of the Society of Toxicology, American College of Toxicology, and 23 additional professional organizations. Question items inquired about gender, age, degree, years of experience, certifications held, areas of specialization, society membership, employment and income. Overall, 1293 responses were received (response rate 21.8%). The results of the 2014 survey provide insight into the job market and career path for current and future toxicologists. PMID:26867944

  19. 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…

  20. 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…

  1. [Tuberculosis prevalence survey in Japan].

    PubMed

    Shimao, Tadao

    2009-11-01

    Chest X-ray examination had been used rather soon after the discovery of X-ray by Rontgen K in 1895 as it was possible to detect chest abnormality by simple radiography. After the discovery of radiophotography independently by Abreu M and Koga Y in 1936, it was applied as a method of mass screening for TB in Japan, and Imamura A made a special lecture on "The mass screening for TB" using radiophotography in 1940 in the Annual Meeting of the Japanese Society for TB. From experiences of mass screening, it was found that there were many cases of TB who do not aware of their own disease, and to know the prevalence of TB, the screening of survey subjects by X-ray examination is indispensable. Noticing the importance of mass health examination by chest X-ray, Dr. Tanaka S, then director of information division, JATAHQ, edited a book entitled "How to carry out mass health examination for TB" in 1951, then he moved to the Ministry of Health and Welfare and engaged in the preparation of the first TB prevalence survey. Random sampling technique was already developed, and health center network covering the whole country was already completed in early 1950s. Using these background, the first TB prevalence survey was conducted in 1953. TB Prevalence Survey Committee was organized asking cooperation of experts in TB, epidemiology and statistics, and the survey in sampled area was carried out by a survey team headed by the director of health center in charge of the sampled area. The survey teams engaged in the survey with enthusiasm, and the rate of response to the survey was 99.3%. The result of this survey was published in the WHO Bulletin, 1955. After the survey in 1953, the following prevalence surveys were carried out in 1958, 1963, 1968 and 1973. Outline of these surveys was shown in Table 1, and the rate of examination was high in all, except the survey in 1973. In this year, TB prevalence survey was carried out in conjunction with the national nutritional survey and the

  2. Survey of April 1995 Graduates.

    ERIC Educational Resources Information Center

    Monson, Kyle C.

    To evaluate the effectiveness of the programs and services at the Community College of the Air Force (CCAF), a survey was conducted of 1,127 students who graduated in April 1995. Study results, based on responses from 34.1% (n=384) of the graduates, included the following: (1) the proportion of females answering the survey was 3% higher that their…

  3. 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…

  4. 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…

  5. Survey of Interlibrary Communications Systems.

    ERIC Educational Resources Information Center

    Kenney, Brigitte L.

    The growth and development of library networks increased the need for more rapid interlibrary communication. This survey describes the history, costs and recent developments of various means of interlibrary communication. Extensive references are provided for each area. The communications systems discussed are: surveys, mail, telephone, facsimile,…

  6. 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…

  7. 2005 Apprenticeship Survey: Summary Report

    ERIC Educational Resources Information Center

    Ministry of Advanced Education, 2005

    2005-01-01

    The 2005 Graduate Follow-up Survey of Apprenticeship Students was a pilot project undertaken by the Ministry of Advanced Education, the Industry Training Authority, and post-secondary institutions (13 public and 9 private). The pilot survey targeted those who completed their apprenticeship technical training programs in a BC post-secondary…

  8. 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,…

  9. 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…

  10. 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…

  11. 100-DR-1 radiological surveys

    SciTech Connect

    Naiknimbalkar, N.M.

    1994-01-28

    This report summarizes and documents the results of the radiological surveys conducted over the surface of the 100-DR-1 Operable Unit, Hanford Site, Richland, Washington. In addition, this report explains the survey methodology using the Ultrasonic Ranging and Data System (USRADS). The 100-DR-1 radiological survey field task consisted of two activities: characterization of the operable unit-specific background conditions and the radiological survey of the operable unit surface area. The survey methodology was based on utilization of USRADS for automated recording of the gross gamma radiation levels at or near 6 in. and at 3 ft from the surface soil. The purpose of the survey is to identify the location of unidentified subsurface radioactive material areas and any surface contamination associated with these areas. The radiological surveys were conducted using both a digital count rate meter with a NaI detector reporting in counts per minute (CPM) and a dose rate meter reporting micro-Roentgen per hour (uR) connected to a CHEMRAD Tennessee Corp. Series 2000 USRADS. The count rate meter was set for gross counting, i.e., Window ``out``. The window setting allows detection of low, intermediate, and high energy photons. The USRADS equipment is used to record the detector readings verses the location of the readings, generate a map of the survey area, and save the data on computer storage media.

  12. SOIL SURVEY GEOGRAPHIC DATABASE (SSURGO)

    EPA Science Inventory

    This data set is a digital soil survey and is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. This data set consists of georeferenced digital map data and computerized attribute data. The map data are in a 7.5 minute quadrangle ...

  13. Feedback: AAP Fifth English Survey.

    ERIC Educational Resources Information Center

    Scottish Office Education Dept., Edinburgh.

    This brochure (which can be used in the classroom as a poster) is intended to provide "a quick way into" the Assessment of Achievement Programme (AAP) English language survey and its findings. The brochure pinpoints the reading purpose and strands that the survey covered. It contains brief sections on performance over time; gender findings;…

  14. CURRENT POPULATION SURVEY NATIVITY SUPPLEMENT

    EPA Science Inventory

    The Current Population Survey (CPS) is a cross-sectional survey conducted with about 57,000 households every month, primarily to measure changes in the labor force. It is conducted by the U.S. Bureau of the Census and administered to panels of respondents, which revolve into the ...

  15. Post High School Plans Survey.

    ERIC Educational Resources Information Center

    Muskingum Area Technical Coll., Zanesville, OH.

    This survey investigated the immediate after-high school plans of high school juniors, with a special emphasis on post-secondary education intentions. The survey included the responses of 1,064 students from 12 high schools. Forty-nine percent of the respondents indicated that they planned to attend a four-year college or university, 18 percent…

  16. PROPOSED SPECIFICATIONS FOR INERTIAL SURVEYING.

    USGS Publications Warehouse

    Chapman, William H.

    1983-01-01

    The purpose of this paper is to continue the movement toward placing inertial surveying instruments in the toolbox of the geodetic surveyor. A set of specifications is proposed for performing horizontal geodetic surveys with inertial instruments that will meet the Federal Geodetic Control Committee (FGCC) second- and third-order standards. These specifications are tentative.

  17. 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.)

  18. NATIONAL STREAM SURVEY DATABASE GUIDE

    EPA Science Inventory

    The National Stream Survey (NSS), conducted in the spring of 1985 and 1986, is one component of the U.S Environmental Protection Agency's National Surface Water Survey. This effort is in support of the National Acid Precipitation Assessment Program. he NSS was a synoptic, spring ...

  19. Handbook for Community Manpower Surveys.

    ERIC Educational Resources Information Center

    Morton, J. E.

    This handbook has been prepared to eliminate some of the gap of manpower information at the local level by assisting local manpower experts in the collection of manpower data. Arranged in the order in which steps are taken in an actual survey, contents of the handbook progress from survey work preceding the fieldwork phase to work taking place…

  20. The National Longitudinal Surveys Handbook.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center for Human Resource Research.

    This volume discussed the research methodology used in the National Longitudinal Surveys of Labor Market Ecperience (NLS). The survey studied employment market conditions for four groups in the labor force: men, aged 45-59; women, aged 30-44; young men, aged 14-24; and young women, aged 14-24. Data were collected on 20,000 individuals over a five…