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Sample records for microquasar cygnus x-1

  1. 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.

  2. 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.

  3. GAMMA-RAY OBSERVATIONS OF THE MICROQUASARS CYGNUS X-1, CYGNUS X-3, GRS 1915+105, AND GX 339–4 WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Bodaghee, Arash; Tomsick, John A.; Pottschmidt, Katja; Rodriguez, Jérôme; Pooley, Guy G.

    2013-10-01

    Detecting gamma-rays from microquasars is a challenging but worthwhile endeavor for understanding particle acceleration and the jet mechanism and for constraining leptonic/hadronic emission models. We present results from a likelihood analysis on timescales of 1 day and 10 days of ∼4 yr worth of gamma-ray observations (0.1-10 GeV) by Fermi-LAT of Cyg X-1, Cyg X-3, GRS 1915+105, and GX 339–4. Our analysis reproduced all but one of the previous gamma-ray outbursts of Cyg X-3 as reported with Fermi or AGILE, plus five new days on which Cyg X-3 is detected at a significance of ∼5σ that are not reported in the literature. In addition, Cyg X-3 is significantly detected on 10 day timescales outside of known gamma-ray flaring epochs, which suggests that persistent gamma-ray emission from Cyg X-3 has been detected for the first time. For Cyg X-1 we find three low-significance excesses (∼3-4σ) on daily timescales that are contemporaneous with gamma-ray flares reported (also at low significance) by AGILE. Two other microquasars, GRS 1915+105 and GX 339–4, are not detected, and we derive 3σ upper limits of 2.3 × 10{sup –8} photons cm{sup –2} s{sup –1} and 1.6 × 10{sup –8} photons cm{sup –2} s{sup –1}, respectively, on the persistent flux in the 0.1-10 GeV range. These results enable us to define a list of the general conditions that are necessary for the detection of gamma-rays from microquasars.

  4. Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Bolton, C.; Murdin, P.

    2000-11-01

    Cygnus X-1 is one of the strongest x-ray sources. It is the first celestial object for which we had reasonably convincing evidence that it is a BLACK HOLE. Its x-ray properties include an ultra-soft spectrum, compared to massive x-ray binaries containing a neutron star, rapid (˜1 s) flickering, and high/low flux states with different spectral characteristics. In 1971, a RADIO SOURCE appeared at...

  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

    2009-12-03

    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.

  6. Extreme particle acceleration in the microquasar CygnusX-3

    NASA Astrophysics Data System (ADS)

    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 γ-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 CygnusX-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 γ-ray flares with energies above 100MeV from the microquasar CygnusX-3 (an exceptional X-ray binary that sporadically produces radio jets). There is a clear pattern of temporal correlations between the γ-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 CygnusX-3, particle energies during the flares can be thousands of times higher than during quiescent states.

  7. The multiwavelength polarization of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Russell, David M.; Shahbaz, Tariq

    2014-03-01

    Polarization measurements of the microquasar Cygnus X-1 exist at γ-ray, X-ray, ultraviolet, optical and radio frequencies. The γ-ray emission has been shown to be highly linearly polarized. Here, we present new infrared polarimetric data of Cygnus X-1 taken with the 10.4 m Gran Telescopio Canarias and the 4.2 m William Herschel Telescope. We show that the broad-band, radio-to-γ-ray flux spectrum and polarization spectrum in the hard state are largely consistent with a simple phenomenological model of a strongly polarized synchrotron jet, an unpolarized Comptonized corona and a moderately polarized interstellar dust component. In this model, the origin of the γ-ray, X-ray and some of the infrared polarization is the optically thin synchrotron power law from the inner regions of the jet. The model requires the magnetic field in this region to be highly ordered and perpendicular to the axis of the resolved radio jet. This differs from studies of some other X-ray binaries, in which the magnetic field is turbulent, variable and aligned with the jet axis. The model is able to explain the approximate polarization strength and position angle at all wavelengths including the detected X-ray (3-5 keV) polarization, except the observed position angle of the γ-ray polarization, which differs from the model by ˜60°. Past numerical modelling has shown that a curved synchrotron spectrum can produce a shift in position angle by ˜60°, which may account for this.

  8. 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.

  9. Cygnus X-1 in the intermediate state

    NASA Astrophysics Data System (ADS)

    Grinberg, V.; Nowak, M.; Wilms, J.; Pooley, G. G.; Pottschmidt, K.; Hell, N.; Tomsick, J. A.; Uttley, P.; Rodriguez, J.

    2014-03-01

    We follow up on ATel #5995 that announced Cygnus X-1 to be entering the hard state. To assess the state of the source we analyze the publicly available MAXI and BAT data following the state definition method for Cyg X-1 introduced in Grinberg et al. ...

  10. 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.

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

    SciTech Connect

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

    2005-01-05

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

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

    NASA Technical Reports Server (NTRS)

    Celik, O.; Harding, A. K.; Hays, E.; Johnson, T. J.; Pottschmidt, K.; Thompson, D. J.

    2009-01-01

    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

    NASA Technical Reports Server (NTRS)

    Celik, O.; Harding, A. K.; Hays, E.; Johnson, T. J.; Pottschmidt, K.; Thompson, D. J.

    2009-01-01

    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.

  14. 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.

  15. Enhanced Gamma-Ray Emission from the Microquasar Cygnus X-3 Detected by AGILE

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

    The AGILE-GRID detector is revealing gamma ray emission above 100 MeV from the microquasar Cygnus X-3. Integrating from 2017-03-15 UT 00:00:00 to 2017-03-16 UT 00:00:00, a preliminary multi-source likelihood analysis finds a gamma-ray flux F( > 100 MeV) = (4.2 +/- 1.7) x 10^-6 photons/cm^2/s with a detection significance near 4 sigma.

  16. The Lukewarm Absorber in the Microquasar Cir X-1

    NASA Astrophysics Data System (ADS)

    Schulz, Norbert S.; Galloway, D. K.; Brandt, W. N.

    2006-09-01

    Through many observations in the last decades the extreme and violent X-ray binary Cir X-1 has been classified as a microquasar, Z-source, X-ray burster, and accreting neutron star exhibiting ultrarelativistic jets. Since the launch of Chandra the source underwent a dramatic change from a high flux (1.5 Crab) source to a rather low persistent flux ( 30 mCrab) in the last year. Spectra from Chandra High Energy Transmission Grating Spectrometer (HETGS) taken during this transformation have revealed many details besides the large overall flux change ranging from blue-shifted absorption lines indicating high-velocity (< 2000 km/s) outflows during high flux, persistently bright lines emission throughout all phases to some form of warm absorption in the low flux phase. Newly released atomic data allows us to analyse specifically the Fe K line region with unprecedented detail for all flux phases observed so far. We also compare these new results with recently released findings of warm absorbers and outflow signatures observed in other microqasars such as GX 339+4, GRS J1655-40, and GRS1915+115.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

    The AGILE-GRID detector is revealing gamma ray emission above 100 MeV from a source positionally consistent with the microquasar Cygnus X-3. Integrating from 2017-02-27 UT 03:00:00 to 2017-03-01 UT 03:00:00 (MJD 57811.125 - 57813.125), a preliminary multi-source likelihood analysis detects a gamma-ray flux F( > 100 MeV) = (3 +/- 1) x 10^-6 photons/cm^2/s with a detection significance near 4 sigma.

  20. Remarkable flaring activity in Cygnus X-1 at 15 GHz

    NASA Astrophysics Data System (ADS)

    Pooley, Guy

    2017-08-01

    The radio emission at 15 GHz from Cygnus X-1 is monitored regularly by the the AMI Large Array at MRAO, Cambridge. The radio flux density is typically near 20 mJy, but is subject to wide variations, including very rare events lasting for some minutes and which are usually termed 'flares'.

  1. 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).

  2. Microquasars

    NASA Astrophysics Data System (ADS)

    Mirabel, I. Félix

    2007-01-01

    Microquasars are compact objects (stellar-mass black holes and neutron stars) in our Galaxy that mimic, on a smaller scale, many of the phenomena seen in quasars. Their discovery provided new insights into the physics of relativistic jets observed elsewhere in the universe, and the accretion jet coupling. Furthermore, microquasars are opening new horizons for the understanding of ultraluminous X-ray sources observed in external galaxies, gamma-ray bursts of long duration, and the origin of stellar black holes and neutron stars. Microquasars are one of the best laboratories to probe General Relativity in the limit of the strongest gravitational fields, and, as such, have become an area of topical interest for both high energy physics and astrophysics. To cite this article: I.F. Mirabel, C. R. Physique 8 (2007).

  3. The Microquasar Cyg X-1: A Short Review

    NASA Technical Reports Server (NTRS)

    Nowak, M. A.; Wilms, J.; Hanke, M.; Pottschmidt, K.; Markoff, S.

    2011-01-01

    We review the spectral properties of the black hole candidate Cygnus X-I. Specifically, we discuss two recent sets of multi-satellite observations. One comprises a 0.5-500 keY spectrum, obtained with eve!)' flying X-ray satellite at that time, that is among the hardest Cyg X-I spectra observed to date. The second set is comprised of 0.5-40 keV Chandra-HETG plus RXTE-PCA spectra from a radio-quiet, spectrally soft state. We first discuss the "messy astrophysics" often neglected in the study of Cyg X-I, i.e., ionized absorption from the wind of the secondary and the foreground dust scattering halo. We then discuss components common to both state extremes: a low temperature accretion disk, and a relativistically broadened Fe line and reflection. Hard state spectral models indicate that the disk inner edge does not extend beyond > or approx.= 40 GM/sq c , and may even approach as close as approx. = 6GM/sq c. The soft state exhibits a much more prominent disk component; however, its very low normalization plausibly indicates a spinning black hole in the Cyg X-I system. Key words. accretion, accretion disks - black hole physics - X-rays:binaries

  4. Enhanced high-energy gamma-ray emission from the microquasar Cygnus X-3 detected by Fermi/LAT

    NASA Astrophysics Data System (ADS)

    Loh, Alan; Corbel, Stephane

    2017-02-01

    Following the recent decrease of the hard X-ray emission from the high-mass X-ray binary Cygnus X-3 as seen by the Swift/Burst Alert Telescope (https://swift.gsfc.nasa.gov/results/transients/CygX-3/), the Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed significant gamma-ray emission originating from the microquasar.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-07-01

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

  7. Analyzing the X-Ray Variability of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Pottschmidt, Katja; Konig, Michael

    The X-ray lightcurves of the black hole candidate Cygnus X-1 exhibit aperiodic variability on time scales ranging from minutes down to milliseconds. This characteristic behavior is usually explained by shot noise models. These models assume that the lightcurve is produced by superposition of randomly occuring shots and an additional white noise component. A more general approach to describe the variability as a stochastic process uses autoregressive [AR] models. Those models express a time series as a linear function of its past values plus a white noise term and provide parameters characterising the temporal correlation of the process. Since the measured X-ray lightcurve is an observation of the system dynamics, it contains observational noise. If this is not accounted for the temporal correlations will be underestimated. Therefore we have applied the Linear State Space Model technique (Koenig \\& Timmer 1996) to explicitely model the observational noise covering an intrinsic autoregressive process. We have reanalysed EXOSAT ME observations of Cygnus X-1 using both common Fourier techniques and the Linear State Space Model technique. We found that the intrinsic process can be described by an AR[1] model with a relaxation time of about 0.3 s. Reference: Koenig, M., Timmer, J. 1996, A\\&A, submitted

  8. 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.

  9. INTEGRAL-RXTE Observations of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Pottschmidt, K.; Wilms, J.; Nowak, M. A.; Dubath, P.; Kreykenbohm, I.; Gleissner, T.; Chernyakova, M.; Rodriguez, J.; Zdziarski, A. A.; Beckman, V.; Kretschmar, P.; Pooley, G. G.; Martínez-Núñez, S.; Courvoisier, T. J.-L.; Schönfelder, V.; Staubert, R.

    2004-10-01

    The canonical black hole binary Cygnus X-1 has been extensively observed during INTEGRAL's performance verification phase in 2002 November and December. The source was found to be in the hard state. About 50 ks of (quasi-)simultaneous RXTE observations have been ob- tained in order to support calibration efforts. Together these observations provide some of the highest quality broad band spectra available for this source. The cam- paign is also supported by radio data obtained with the Ryle telescope. We present an analysis of the broad band spectra using several Comptonization models. Compared to our earlier presentations of this data set, a new RXTE- PCA calibration and a much improved INTEGRAL-SPI response have been used. This allows to better constrain important physical parameters of the accretion process such as the temperature and optical depth of the corona as well as the reflection fraction. Key words: black hole physics — stars: individual (Cygnus X-1) — Gamma-rays: observations — X-rays: binaries — X-rays: general.

  10. 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.

  11. 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.

  12. Composition, Collimation, Contamination: The Jet of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Heinz, S.

    2006-01-01

    We model the observed size and brightness of the VLBA radio core of the jet in Cygnus X-1 to derive an expression for the jet power as a function of basic jet parameters. We apply this expression to recent constraints on the jet power from observations of a large-scale shocked shell around the source by Gallo and coworkers, which leads us to a set of alternative conclusions: either (1) the jet contains large amounts of protons (>=2000 protons per radio-emitting electron), (2) it has a very low volume filling factor of f<~3×10-5, (3) the steady, radio-emitting VLBA jet is not the source of the kinetic energy powering the ISM shell, or (4) its asymptotic behavior differs fundamentally from a broad set of plausible analytic jet models.

  13. Gamma-ray spectral variability of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    McConnell, M. L.; Bennett, K.; Bloemen, H.; Collmar, W.; Hermsen, W.; Kuiper, L.; Paciesas, W.; Phlips, B.; Poutanen, J.; Ryan, J. M.; Schönfelder, V.; Steinle, H.; Strong, A. W.; Zdziarski, A. A.

    2001-10-01

    We have used observations from CGRO to study the variation in the MeV emission of Cygnus X-1 between its low and high X-ray states. These data provide a measurement of the spectral variability above 1 MeV. The high state MeV spectrum is found to be much harder than that of the low state MeV spectrum. In particular, the power-law emission seen at hard X-ray energies in the high state spectrum (with a photon spectral index of 2.6) is found to extend out to at least 5 MeV, with no evidence for any cutoff. Here we present the data and describe our efforts to model both the low state and high state spectra using a hybrid thermal/nonthermal model in which the emission results from the Comptonization of an electron population that consists of both a thermal and nonthermal component. .

  14. Pion production In The Inner Disk Around Cygnus X-1

    SciTech Connect

    Meirelles Filho, C.; Miyake, H.; Timoteo, V.S.; Lima, C.L

    2004-12-02

    Neutron production via 4He breakup and p(p, n{pi}+)p is considered in the innermost region of an accretion disk surrounding a Kerr Black Hole. Close to the horizon, the contribution from p(p, n{pi}+)p to the neutron production is comparable to that from the breakup. It is shown that the viscosity generated by the collisions of the accreting matter with the neutrons may drive stationary accretion, for accretion rates below a critical value. In this case, solution to the disk equations is double-valued and for both solutions protons overnumber the pairs. We suggest that these solutions may mimic the states of high and low luminosity observed in Cygnus X-1.

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

    NASA Astrophysics Data System (ADS)

    Miskovicova, Ivica

    2012-07-01

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

  16. A LIKELY MICRO-QUASAR IN THE SHADOW OF M82 X-1

    SciTech Connect

    Xu, Xiao-jie; Liu, Jifeng; Liu, Jiren E-mail: jfliu@nao.cas.cn

    2015-02-01

    The ultra-luminous X-ray source M82 X-1 is one of the most promising intermediate mass black hole candidates in the local universe based on its high X-ray luminosities (10{sup 40}–10{sup 41} erg s{sup −1}) and quasi-periodic oscillations, and is possibly associated with a radio flare source. In this work, applying the sub-pixel technique to the 120 ks Chandra observation (ID: 10543) of M82 X-1, we split M82 X-1 into two sources separated by 1.″1. The secondary source is not detected in other M82 observations. The radio flare source is not found to associate with M82 X-1, but is instead associated with the nearby transient source S1 with an outburst luminosity of ∼10{sup 39} erg s{sup −1}. With X-ray outburst and radio flare activities analogous to the recently discovered micro-quasar in M31, S1 is likely to be a micro-quasar hidden in the shadow of M82 X-1.

  17. 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.

  18. 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.

  19. 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.

  20. INTEGRAL-RXTE observations of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Pottschmidt, K.; Wilms, J.; Chernyakova, M.; Nowak, M. A.; Rodriguez, J.; Zdziarski, A. A.; Beckmann, V.; Kretschmar, P.; Gleissner, T.; Pooley, G. G.; Martínez-Núñez, S.; Courvoisier, T. J.-L.; Schönfelder, V.; Staubert, R.

    2003-11-01

    We present first results from contemporaneous observations of Cygnus X-1 with INTEGRAL and RXTE, made during INTEGRAL's performance verification phase in 2002 November and December. Consistent with earlier results, the 3-250 keV data are well described by Comptonization spectra from a Compton corona with a temperature of kT ~ 50-90 keV and an optical depth of tau ~ 1.0-1.3 plus reflection from a cold or mildly ionized slab with a covering factor of Omega /2pi ~ 0.2-0.3. A soft excess below 10 keV, interpreted as emission from the accretion disk, is seen to decrease during the 1.5 months spanned by our observations. Our results indicate a remarkable consistency among the independently calibrated detectors, with the remaining issues being mainly related to the flux calibration of INTEGRAL. Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland, and with the participation of Russia and the USA.

  1. Gamma-Ray Variability of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    McConnell, Mark; Ryan, James; Zdziarski, Andrzej; Bennett, Kevin; Bloemen, Hans; Hermsen, Wim; Kuiper, Lucien; Collmar, Werner; Schoenfelder, Volker; Steinle, Helmut; Strong, Andrew; Paciesas, William; Phlips, Bernard; Poutanen, Juri

    2002-04-01

    We have used observations of Cygnus X-1 from the Compton Gamma-Ray Observatory (CGRO) and BeppoSAX to study the variation in the MeV gamma-ray emission between the hard and soft spectral states, using spectra that cover the energy range 20 keV up to 10 MeV. These data provide evidence for significant spectral variability at energies above 1 MeV. In particular, whereas the hard X-ray flux decreases during the soft state, the flux at energies above 1 MeV increases, resulting in a significantly harder gamma-ray spectrum at energies above 1 MeV. This behavior is consistent with the general picture of galactic black hole candidates having two distinct spectral forms at soft gamma-ray energies. These data extend this picture, for the first time, to energies above 1 MeV. We have used two different hybrid thermal/non-thermal Comptonization models to fit broad band spectral data obtained in both the hard and soft spectral states. These fits provide a quantitative estimate of the electron distribution and allow us to probe the physical changes that take place during transitions between the low and high X-ray states. We find that there is a significant increase (by a factor of 4) in the bolometric luminosity as the source moves from the hard state to the soft state.

  2. Synchrotron and Coulomb Boiler in Cygnus X-1

    SciTech Connect

    Malzac, Julien; Belmont, Renaud

    2009-05-11

    We use a new code to simulate the radiation and kinetic processes in the X-ray emitting region around accreting black holes and constrain the magnetic field and temperature of the hot protons in the corona of Cygnus X-1. In the hard state we find a magnetic field below equipartition with radiation, suggesting that the corona is not powered through magnetic field dissipation (as assumed in most accretion disc corona models). On the other hand, our results also point toward proton temperatures that are substantially lower than typical temperatures of the ADAF models. Finally, we show that in both spectral states Comptonising plasma could be powered essentially through power-law acceleration of non-thermal electrons, which are then partly thermalised by the synchrotron and Coulomb boiler. This suggests that, contrary to current beliefs, the corona of the HSS and that of the LHS could be of very similar nature. The differences between the LHS and HSS coronal spectra would then be predominantly caused by the strong disc soft cooling emission which is present in the HSS and absent in the LHS.

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

    SciTech Connect

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

    2011-12-01

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

  4. 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.

  5. 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⊙ black hole.

  6. 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.

  7. 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.

  8. Observations of Cygnus X-1 in the MeV band by the INTEGRAL imager

    NASA Astrophysics Data System (ADS)

    Walter, R.; Xu, M.

    2017-06-01

    Context. The spectrum of the MeV tail detected in the black-hole candidate Cygnus X-1 remains controversial as it appeared much harder when observed with the INTEGRAL Imager IBIS than with the INTEGRAL spectrometer SPI or CGRO. Aims: We present an independent analysis of the spectra of Cygnus X-1 observed by IBIS in the hard and soft states. Methods: We developed a new analysis software for the PICsIT detector layer and for the Compton mode data of the IBIS instrument and calibrated the idiosyncrasies of the PICsIT front-end electronics. Results: The spectra of Cygnus X-1 obtained for the hard and soft states with the INTEGRAL imager IBIS are compatible with those obtained with the INTEGRAL spectrometer SPI, with CGRO, and with the models that attribute the MeV hard tail either to hybrid thermal/non-thermal Comptonisation or to synchrotron emission.

  9. 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.

  10. 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.

  11. 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.

  12. RXTE Observation of Cygnus X-1: Spectra and Timing

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    We present preliminary results from the analysis of an R.XTE observation of Cyg X-1 in the hard state. We show that the observed X-ray spectrum can be explained with a model for an accretion disk corona (ADC), in which a hot sphere is situated inside of a cold accretion disk (similar to an advection dominated model). ADC Models with a slab-geometry do not successfully fit the data. In addition to the spectral results we present the observed temporal properties of Cyg X-1, i.e. the coherence-function and the time-lags, and discuss the constraints the. temporal properties imply for the accretion geometry in Cyg X-1.

  13. Cygnus X-1: Dips and Low Frequency Noise

    NASA Technical Reports Server (NTRS)

    Wilms, Joern

    2000-01-01

    The primary science result to come out of this work is the discovery that the time lags between hard and soft variability in Cyg X-1 show dramatic spikes during the transitions between hard and soft states (and possibly during "failed transitions" to the soft state), but are remarkably similar between the main soft and hard states. This work is being continued and elaborated upon with ongoing RXTE monitoring campaigns.

  14. Magnetic Field in X-Ray Binary Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Karitskaya, E. A.; Bochkarev, N. G.; Hubrig, S.; Gnedin, Yu. N.; Pogodin, M. A.; Yudin, R. V.; Agafonov, M. I.; Sharova, O. I.

    Our spectroscopic observations with FORS1 at 8.2-m VLT telescope (Paranal, Chile) lead to detection of magnetic field in the X-ray binary Cyg X-1. That is the first successful attempt of measuring magnetic field in a binary with a black hole. The value of the mean longitudinal magnetic field in optical component (O9.7 Iab supergiant) changes regularly with the orbital phase reaching its maximum of 130 G (σ≈20 G). The measurements based on Zeeman effect were carried through over all observed supergiant photosphere absorption spectral lines. Similar measurements over the emission line He II λ 4686 Å yielded a value of several hundreds Gauss of a smaller significance level. The system Doppler tomogram we build over the line profiles shows that He II λ 4686 Å originates in the outer regions of the accretion structure. The values measured correspond, in the frame of the disc accretion standard model, to a near-black-hole field of ˜ 10^8-10^9 G and may be responsible for the observed Cyg X-1 X-ray flickering. Also some consequences of such magnetic field existence in Cyg X-1 optical component photosphere were suggested.

  15. Spectroscopic observations of the optical candidate for Cygnus X-1.

    NASA Technical Reports Server (NTRS)

    Brucato, R.; Kristian, J.

    1973-01-01

    The spectroscopic binary BD+34 3815 (= HDE 226868) with a period of 5.6 days, which is the brightest object in the position box for the X-ray source Cyg X-1, is studied to determine whether it meets all the requirements for being a black hole. Evidence is presented that the mass of the secondary is larger than the upper limits for white dwarfs or neutron stars, but there is no conclusive evidence that the optical binary is an X-ray source, and that the secondary is a collapsed object.

  16. A Complete Binary Orbit of Cygnus X-1: Spectroscopic Analysis

    NASA Astrophysics Data System (ADS)

    Garcia, Javier; Uttley, Phil; Wilms, Joern; Grinberg, Victoria; Pottschmidt, Katja; Dauser, Thomas

    2017-08-01

    In 2016 we observed the canonical black hole binary system Cyg X-1/HDE226868 for a full 5.6-day orbit. We present preliminary results of the ionization state and composition of the plasma surrounding the black hole by looking at the XMM-Newton RGS spectra. Using newly improved reflection models, which include a Comptonization continuum, density and radial ionization effects; we also present an analysis of the reflected spectra observed simultaneously with XMM-Newton and NuSTAR, effectively covering the 0.3-50 keV energy range.

  17. 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.

  18. 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.

  19. INTEGRAL/RXTE Observations of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Wilms, J.; Pottschmidt, K.; Nowak, M. A.; Chernyakova, M.; Rodriguez, J.; Zdziarski, A. A.; Beckmann, V.; Kretschmar, P.; Gleissner, T.; Pooley, G. G.; Martínez-Núñez, S.; Courvoisier, T. J.-L.; Schönfelder, V.; Staubert, R.

    2004-07-01

    We present results from simultaneous observations of Cyg X-1 with INTEGRAL and RXTE in 2002 November and December, employing the new RXTE calibration from HEASOFT 5.3. The broad-band X-ray/γ-ray spectrum is well described by Comptonization spectra with an additional reflection component. The temperature of the Comptonizing plasma is kTe ~ 60-80 keV and its optical depth is τ ~ 0.8-1.2. The covering factor of the reflector is Ω/2π ~ 0.1. There is a possible soft excess below 10 keV, interpreted as emission from the accretion disk. The spectral parameters are slightly different from those obtained by us earlier due to the different RXTE-PCA calibration.

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

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  1. Gamma rays detected from Cygnus X-1 with likely jet origin

    NASA Astrophysics Data System (ADS)

    Zanin, R.; Fernández-Barral, A.; de Oña Wilhelmi, E.; Aharonian, F.; Blanch, O.; Bosch-Ramon, V.; Galindo, D.

    2016-11-01

    Aims: We probe the high-energy (>60 MeV) emission from the black hole X-ray binary system, Cygnus X-1, and investigate its origin. Methods: We analyzed 7.5 yr of data by Fermi-LAT with the latest Pass 8 software version. Results: We report the detection of a signal at 8σ statistical significance that is spatially coincident with Cygnus X-1 and has a luminosity of 5.5 × 1033 erg s-1, above 60 MeV. The signal is correlated with the hard X-ray flux: the source is observed at high energies only during the hard X-ray spectral state, when the source is known to display persistent, relativistic radio-emitting jets. The energy spectrum, extending up to 20 GeV without any sign of spectral break, is well fit by a power-law function with a photon index of 2.3 ± 0.2. There is a hint of orbital flux variability, with high-energy emission mostly coming around the superior conjunction. Conclusions: We detected GeV emission from Cygnus X-1 and probed that the emission is most likely associated with the relativistic jets. The evidence of flux orbital variability indicates the anisotropic inverse-Compton on stellar photons as the mechanism at work, thus constraining the emission region to a distance 1011-1013 cm from the black hole.

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

    NASA Astrophysics Data System (ADS)

    Grinberg, Victoria

    2014-01-01

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

  3. X-ray and UV spectroscopy of Cygnus X-1 = HDE226868

    NASA Technical Reports Server (NTRS)

    Pravdo, S. H.; White, N. E.; Kondo, Y.; Becker, R. H.; Boldt, E. A.; Holt, S. S.; Serlemitsos, P. J.; Mccluskey, B. G.

    1980-01-01

    Observations are presented of Cygnus X-1 with the solid-state spectrometer on the Einstein Observatory. The X-ray spectra of two intensity dips viewed near superior conjunction did not exhibit increased photoelectric absorption. Rather the data support a model in which an increase in the electron scattering optical depth modifies both the observed spectrum and the intensity. The characteristic temperature of the intervening material is greater than 5 x 10 to the 7th power K. These measurements were in part simultaneous with observations by IUE. The ultra violet spectrum and intensity remained relatively constant during an X-ray intensity dip.

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  5. 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.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  7. THE 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.

  8. 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.

  9. Low charge states of Si and S in Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Hell, Natalie; Miškovičová, I.; Brown, G. V.; Wilms, J.; Clementson, J.; Hanke, M.; Beiersdorfer, P.; Liedahl, D.; Pottschmidt, K.; Porter, F. S.; Kilbourne, C. A.; Kelley, R. L.; Nowak, M. A.; Schulz, N. S.

    2013-09-01

    Strong, relatively short, absorption dips have been observed in the x-ray light curves measured from the high mass x-ray binary system Cygnus X-1. With increasing strength of the dips, which are believed to be caused by ‘clumps’ of cold material present in the stellar wind of Cyg X-1's companion star, K-shell absorption lines in L-shell ions of Si and S develop. To determine the bulk motion of the clumps via the Doppler shifts of these lines with high accuracy, we measured their reference energies using the Lawrence Livermore National Laboratory electron beam ion trap EBIT-I and EBIT Calorimeter Spectrometer. Our findings—shifts consistent with zero velocity of the absorber throughout all ionization states at orbital phase zero—provide evidence for an onion-like ion structure of the clumps.

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  11. 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.

  12. An upper limit on ultraviolet shot noise from Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Duthie, J. G.; Mcmillan, R. S.

    1979-01-01

    Rapid photometry of Cygnus X-1 through an ultraviolet filter centered on 0.35 micron has been obtained at 100-ms sampling intervals. The autocorrelation function of these data has been examined for shot noise analogous to the behavior of the X-ray light curve. The ultraviolet data are entirely consistent with white noise. Considering randomly occurring ultraviolet shots with the same duration (0.5 s) and average rate (1 per sec) as the X-ray shots, a 3-sigma upper limit on the ratio of optical to X-ray energies per shot is estimated to be 0.13, before the ultraviolet light is attenuated by interstellar dust. This limit is then generalized for shots of arbitrary duration and rate.

  13. 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.

  14. Low Charge States of Si and S: from Cygnus X-1 to the Lab and Back

    NASA Astrophysics Data System (ADS)

    Hell, Natalie; Miškovičova, I.; Hanke, M.; Brown, G. V.; Wilms, J.; Clementson, J.; Beiersdorfer, P.; Liedahl, D. A.; Pottschmidt, K.; Porter, F.; Kilbourne, C.; Kelley, R. L.; Nowak, M.; Schulz, N. S.

    2013-04-01

    The X-ray light curves of the high mass X-ray binary (HMXB) Cygnus X-1 are shaped by strong, relatively short, absorption dips. While spectra extracted from the dip free phases are dominated by absorption lines of the Rydberg series of H- and He-like ions, 1s-2p transitions of lower ionized Si and S appear in the dip spectra. This shift in charge balance suggests that we probe “clumps” of cold material embedded in the companion's stellar wind as they cross our line of sight. Determining the bulk motion of these clumps by measuring the Doppler shifts of these lines as a function of dipping strength and ionization state can confirm this theory. Unfortunately, the predicted uncertainty for theoretical calculations - if available at all - is of the order of the expected shifts in the system. To overcome this lack of reliable reference wavelengths, we measured the Kα spectra of H- through F-like Si and S with the EBIT Calorimeter Spectrometer (ECS) and the Lawrence Livermore National Laboratory electron beam ion trap EBIT-I. We then directly apply these new line centers to calculate the Doppler shifts of the lines observed in Cygnus X-1. With this approach, we find shifts consistent with constant velocity of the absorber throughout all ionization states and, hence, provide evidence for an onion-like ion structure of the clumps. Funded by BMWi under DLR grant 50OR1207. Work at LLNL was performed under the auspices of DOE under contract DE-AC52-07NA27344 and supported by NASA grants.

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

    SciTech Connect

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

    2012-03-10

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

  16. 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

  17. 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

  18. 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.

  19. Galactic microquasar transients with AGILE

    NASA Astrophysics Data System (ADS)

    Munar-Adrover, Pere; Piano, Giovanni; Sabatini, S.; Tavani, M.; Lucarelli, F.; Verrecchia, F.; Pittori, C.

    2017-01-01

    The AGILE satellite has been proven to be an excellent tool to study transient gamma-ray sources since it entered in a spinning operational mode in 2009. Thanks to its scanning capabilities it observes the whole sky every few hours. Several new interesting systems were discovered, such as AGL J2241+4454 in 2010, probably associated to the mysterious black-hole high-mass X-ray binary MWC 656. With a state of the art PSF and sensitivity in the 100 MeV - 1 GeV energy range, AGILE studied this system in order to identify new periods of gamma-ray activity that could be associated to the binary, and found a total of 10 flares spanning from 2008 until 2013. AGILE studied also the Cygnus region, finding evidence of a new recent gamma-ray flare from the microquasar Cygnus X-3, with a flux of ˜ 2×10-8 ph cm-2 s, during a state transition phase in the bright high-soft X-ray state. Also Cygnus X-1 was detected in the past by AGILE, although both systems are very different and show different behaviour.

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

    SciTech Connect

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

    2005-07-27

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

  1. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  3. 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.

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

    SciTech Connect

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

    2013-04-20

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

  5. USING THE X-RAY DUST SCATTERING HALO OF CYGNUS X-1 TO DETERMINE DISTANCE AND DUST DISTRIBUTIONS

    SciTech Connect

    Xiang Jingen; Lee, Julia C.; Nowak, Michael A.; Wilms, Joern E-mail: jclee@cfa.harvard.edu

    2011-09-01

    We present a detailed study of the X-ray dust scattering halo of the black hole candidate Cygnus X-1 based on two Chandra High Energy Transmission Gratings Spectrometer observations. Using 18 different dust models, including one modified by us (eponymously dubbed XLNW), we probe the interstellar medium between us and this source. A consistent description of the cloud properties along the line of sight (LOS) that describes at the same time the halo radial profile, the halo light curves, and the column density from source spectroscopy is best achieved with a small subset of these models. Combining the studies of the halo radial profile and the halo light curves, we favor a geometric distance to Cygnus X-1 of d = 1.81 {+-} 0.09 kpc. Our study also shows that there is a dense cloud, which contributes {approx}50% of the dust grains along the LOS to Cygnus X-1, located at {approx}1.6 kpc from us. The remainder of the dust along the LOS is close to the black hole binary.

  6. Spectral Variability of Cygnus X-1 at Energies Above 1 MeV

    NASA Astrophysics Data System (ADS)

    McConnell, M. L.; Ryan, J. M.; Collmar, W.; Schönfelder, V.; Steinle, H.; Strong, A. W.; Bloemen, H.; Hermsen, W.; Kuiper, L.; Bennett, K.; Paciesas, W.; Phlips, B.; Poutanen, J.; Zdziarski, A. A.

    2000-10-01

    The time-dependent behavior of Cygnus X-1 at energies below several hundred keV has been extensively observed. At X-ray energies, it is highly variable on time scales ranging from msecs to months. On long time scales, the emission varies between the low ('hard') X-ray state and the high ('soft') X-ray state. The low X-ray state spectrum can be described as a power-law at soft X-ray energies followed by an exponential cutoff at higher energies with an e-folding energy of ~100 keV. The high X-ray state spectrum can be described as a blackbody at soft X-ray energies followed by a power-law extending up to at least several hundred keV. At higher energies, near 1 MeV and above, relatively little is known about the time variations of the emission. We have used observations from CGRO to study the variation in the MeV emission between the low and high X-ray states. These data, in particular those from COMPTEL, provide a measurement of the spectrum above 1 MeV. The high state MeV spectrum is found to be much harder than that of the low state MeV spectrum. In particular, the power-law emission seen in the high state spectrum (with a photon spectral index of 2.5) is found to extend out to at least 5 MeV with no evidence for any cutoff. The extension of the powerlaw spectrum to such high energies is inconsistent with models based on bulk motion Comptonization. Here we shall present the data and describe the results from modeling both the low state and high state spectra using a hybrid thermal/nonthermal model in which the emission results from the Comptonization of an electron population that consists of both a thermal and nonthermal component.

  7. AstroSat/LAXPC Observation of Cygnus X-1 in the Hard State

    NASA Astrophysics Data System (ADS)

    Misra, Ranjeev; Yadav, J. S.; Verdhan Chauhan, Jai; Agrawal, P. C.; Antia, H. M.; Pahari, Mayukh; Chitnis, V. R.; Dedhia, Dhiraj; Katoch, Tilak; Madhwani, P.; Manchanda, R. K.; Paul, B.; Shah, Parag

    2017-02-01

    We report the first analysis of data from AstroSat/LAXPC observations of Cygnus X-1 in 2016 January. LAXPC spectra reveals that the source was in the canonical hard state, represented by a prominent thermal Comptonization component having a photon index of ∼1.8 and high temperature of kTe > 60 keV along with weak reflection and possible disk emission. The power spectrum can be characterized by two broad lorentzian functions centered at ∼0.4 and ∼3 Hz. The rms of the low-frequency component decreases from ∼15% at around 4 keV to ∼10% at around 50 keV, while that of the high-frequency one varies less rapidly from ∼13.5% to ∼11.5% in the same energy range. The time lag between the hard (20–40 keV) and soft (5–10 keV) bands varies in a step-like manner being nearly constant at ∼50 milliseconds from 0.3 to 0.9 Hz, decreasing to ∼8 milliseconds from 2 to 5 Hz and finally dropping to ∼2 milliseconds for higher frequencies. The time lags increase with energy for both the low and high-frequency components. The event mode LAXPC data allows for flux resolved spectral analysis on a timescale of 1 s, which clearly shows that the photon index increased from ∼1.72 to ∼1.80 as the flux increased by nearly a factor of two. We discuss the results in the framework of the fluctuation propagation model.

  8. 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.

  9. 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

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

    NASA Technical Reports Server (NTRS)

    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.; hide

    2016-01-01

    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 < approx. a* < approx. 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 approx.10deg-15deg. 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 approx. 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.

  11. 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.

  12. A High-Sensitivity Measurement of the MeV Gamma-Ray Spectrum of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    McConnell, M. L.; Ryan, J. M.; Collmar, W.; Schönfelder, V.; Steinle, H.; Strong, A. W.; Bloemen, H.; Hermsen, W.; Kuiper, L.; Bennett, K.; Phlips, B. F.; Ling, J. C.

    2000-11-01

    The Compton Gamma Ray Observatory (CGRO) has observed the Cygnus region on several occasions since its launch in 1991. The data collected by the COMPTEL experiment on CGRO represent the most sensitive observations to date of Cygnus X-1 in the 0.75-30 MeV range. A spectrum accumulated by COMPTEL over 10 weeks of observation time shows significant evidence for emission extending out to several MeV. We have combined these data with contemporaneous data from both BATSE and OSSE to produce a broadband γ-ray spectrum, corresponding to the low X-ray state of Cygnus X-1, extending from 50 keV up to ~5 MeV. Although there is no evidence for any broad-line-like emissions in the MeV region, these data further confirm the presence of a hard tail at energies above several hundred keV. In particular, the spectrum at MeV energies can be described as a power law with a photon spectral index of α=-3.2, with no evidence for a cutoff at high energies. For the 200 keV-5 MeV spectrum, we provide a quantitative description of the underlying electron spectrum, in the context of a hybrid thermal/nonthermal model for the emission. The electron spectrum can be described by a thermal Maxwellian with a temperature of kTe=86 keV and a nonthermal power-law component with a spectral index of pe=4.5. The spectral data presented here should provide a useful basis for further theoretical modeling.

  13. 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).

  14. Gamma-ray absorption and the origin of the gamma-ray flare in Cygnus X-1

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

    Context. The high-mass microquasar Cyg X-1, the best-established candidate for a stellar-mass black hole in the Galaxy, has been detected in a flaring state at very high energies (VHE), E > 200 GeV, by the Atmospheric Cherenkov Telescope MAGIC. The flare occurred at orbital phase ϕ = 0.91, where ϕ = 1 is the configuration with the black hole behind the companion high-mass star, when the absorption of gamma-ray photons by photon-photon annihilation with the stellar field is expected to be highest. Aims: We aim to set up a model for the high-energy emission and absorption in Cyg X-1 that can explain the nature of the observed gamma-ray flare. Methods: We study the gamma-ray opacity due to pair creation along the whole orbit, and for different locations of the emitter. Then we consider a possible mechanism for the production of the VHE emission. Results: We present detailed calculations of the gamma-ray opacity and infer from these calculations the distance from the black hole where the emitting region was located. We suggest that the flare was the result of a jet-clump interaction where the decay products of inelastic p - p collisions dominate the VHE outcome. Conclusions: We are able to reproduce the spectrum of Cyg X-1 during the observed flare under reasonable assumptions. The flare may be the first event of jet-cloud interaction ever detected at such high energies.

  15. 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.

  16. 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.

  17. 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.

  18. NuSTAR AND SUZAKU OBSERVATIONS OF THE HARD STATE IN CYGNUS X-1: LOCATING THE INNER ACCRETION DISK

    SciTech Connect

    Parker, M. L.; Lohfink, A.; Fabian, A. C.; Alston, W. N.; Kara, E.; Tomsick, J. A.; Boggs, S. E.; Craig, W. W.; Miller, J. M.; Yamaoka, K.; Nowak, M.; Grinberg, V.; Christensen, F. E.; Fürst, F.; Grefenstette, B. W.; Harrison, F. A.; Gandhi, P.; Hailey, C. J.; King, A. L.; Stern, D.; and others

    2015-07-20

    We present simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR ) and Suzaku observations of the X-ray binary Cygnus X-1 in the hard state. This is the first time this state has been observed in Cyg X-1 with NuSTAR, which enables us to study the reflection and broadband spectra in unprecedented detail. We confirm that the iron line cannot be fit with a combination of narrow lines and absorption features, instead requiring a relativistically blurred profile in combination with a narrow line and absorption from the companion wind. We use the reflection models of García et al. to simultaneously measure the black hole spin, disk inner radius, and coronal height in a self-consistent manner. Detailed fits to the iron line profile indicate a high level of relativistic blurring, indicative of reflection from the inner accretion disk. We find a high spin, a small inner disk radius, and a low source height and rule out truncation to greater than three gravitational radii at the 3σ confidence level. In addition, we find that the line profile has not changed greatly in the switch from soft to hard states, and that the differences are consistent with changes in the underlying reflection spectrum rather than the relativistic blurring. We find that the blurring parameters are consistent when fitting either just the iron line or the entire broadband spectrum, which is well modeled with a Comptonized continuum plus reflection model.

  19. Evidence for an about 300 day period in Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Priedhorsky, W. C.; Terrell, J.; Holt, S. S.

    1983-01-01

    Results from 10 years of observation of Cyg X-1 by the Vela 5B satellite are reported. Good evidence for an approximately 300 day period is found, which is confirmed by independent data from the All-Sky Monitor instrument on Ariel 5. Cyg X-1 varies by about 25 percent with a 294 + or -4 day period. This modulation is apparently unrelated to the known transitions between the source high and low states. Flux minima occur at 1974.05+nP. The 294 day period is consistent with the precession of the supergiant companion HDE 226868 and also with the precession period of a tilted accretion disk. The light curve could be modulated by a change in the mass transfer rate or variable obscuration by ionized matter.

  20. Interpretation of the gamma-ray bump from Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Liang, Edison P.; Dermer, Charles D.

    1988-01-01

    The strong 0.5-2 MeV gamma-ray bump of Cyg X-1 recently reported by HEAO 3 observers can be interpreted self-consistently as the emission from a hot (kT of about 400 keV) pair-dominated plasma. The emission region parameters are uniquely determined by the spectral fit and observed luminosity via the pair-balance condition, suggesting that the gamma rays are produced in the inner region of the accretion flow at the expense of the normal power-law hard X-rays.

  1. On the physical reality of the millisecond bursts in Cygnus X-1 - Bursts and shot noise

    NASA Technical Reports Server (NTRS)

    Weisskopf, M. C.; Sutherland, P. G.

    1978-01-01

    The method of data analysis used to interpret the millisecond temporal structure of Cyg X-1 is discussed. In particular, the effects produced by the shot-noise variability of this source, which occurs on time scales of about 0.5 s, are examined. Taking into account the recent discovery that only about 30% of the flux may be in the shots, it is found that spurious 'millisecond bursts' will be detected. A comparison of the properties of these bursts with currently published experimental data is performed.

  2. 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.

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

    NASA Technical Reports Server (NTRS)

    1980-01-01

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

  4. X-ray variability of Cygnus X-1 in its soft state

    NASA Technical Reports Server (NTRS)

    Cui, W.; Zhang, S. N.; Jahoda, K.; Focke, W.; Swank, J.; Heindl, W. A.; Rothschild, R. E.

    1997-01-01

    Observations from the Rossi X-ray Timing Explorer (RXTE) of Cyg X-1 in the soft state and during the soft to hard transition are examined. The results of this analysis confirm previous conclusions that for this source there is a settling period (following the transition from the hard to soft state during which the low energy spectrum varies significantly, while the high energy portion changes little) during which the source reaches nominal soft state brightness. This behavior can be characterized by a soft low energy spectrum and significant low frequency 1/f noise and white noise on the power density spectrum, which becomes softer upon reaching the true soft state. The low frequency 1/f noise is not observed when Cyg X-1 is in the hard state, and therefore appears to be positively correlated with the disk mass accretion rate. The difference in the observed spectral and timing properties between the hard and soft states is qualitatively consistent with a fluctuating corona model.

  5. Linear polarization from tidal distortions of the Cygnus X-1 primary component

    SciTech Connect

    Bochkarev, N.G.; Karitskaia, E.A.; Loskutov, V.M.; Sokolov, V.V.

    1986-02-01

    The variability that would be introduced into the optical linear polarization of the Cyg X-1 (V1357 Cyg) binary system due to tidal deformation or shallow partial eclipses of the primary component is calculated, allowing for the optical-depth variation of the source function and single-scattering albedo in a model stellar atmosphere with Teff = 32,900 K and log g = 3.1. Angular distributions of the intensity and polarization per unit area of the stellar surface are derived for selected wavelengths, and the wavelength dependence of the corresponding polarization variability amplitude Ap is predicted. In the optical range Ap should be less than about 0.025 percent, but in principle might be detectable at short wavelengths. The observed V-band variations in p are, however an order of magnitude stronger and cannot result from tidal distortions or partial eclipses. 24 references.

  6. NuSTAR Discovery of a Possible Black Hole HMXB and Cygnus X-1 Progenitor

    NASA Astrophysics Data System (ADS)

    Grindlay, Jonathan E.; Hailey, Charles James; Zhang, Shuo; Mori, Kaya; Gomez, Sebastian; Hong, Jaesub; Tomsick, John

    2017-01-01

    We report on NuSTAR observations of HD96670, a single line spectroscopic binary in the Carina OB association. We selected this source as a possible BH-HMXB candidate based on its 5.53d orbital period and 0.10 Msun mass function, both similar to Cyg X-1. HD96670 is a O8.5V main sequence star, and if its secondary were a BH, and its O star evolves to a O9Ib star like that in Cyg X-1, it would be high luminosity BH-HXMB. HD96670 is detected as a soft source in RASS and in the XMM slew survey. With a 150 ksec exposure with NuSTAR, we found a best-fit power law spectrum with photon index 2.4 - 2.6 and factor of ~2 variability. The mean Lx ~ 5 x 10^32 (5 - 30 keV) is consistent with that expected for accretion from the weak wind that late-type main sequence O stars usually show for plausible assumptions for the secondary if it is a ~5Msun BH. In the poster by Gomez and Grindlay, we show the detailed photometry and spectroscopy and PHOEBE modelling which point to the secondary indeed being a 5 Msun object, either an accreting BH or possibly a B8V star for which the X-ray spectrum would be expected to not show the hard PL component. Additional X-ray observations at or near the optically determined phase of inferiour vs. superior conjunction will resolve the nature of the secondary. If it is indeed a BH, this points the way to a much larger population of low-luminosity (Weak Wind) BH-LMXBs, with longer lifetimes, than the presently explored systems which all (but one) have super-giant donors.

  7. Black hole spin of Cygnus X-1 determined from the softest state ever observed

    NASA Astrophysics Data System (ADS)

    Kawano, Takafumi; Done, Chris; Yamada, Shin'ya; Takahashi, Hiromitsu; Axelsson, Magnus; Fukazawa, Yasushi

    2017-03-01

    We show the softest ever spectrum from Cyg X-1, detected in 2013 with Suzaku. This has the weakest high-energy Compton tail ever seen from this object, so should give the cleanest view of the underlying disk spectrum, and hence the best determination of black hole spin from disk continuum fitting. Using the standard model of a disk with simple non-thermal Comptonization to produce the weak high-energy tail gives a high-spin black hole. However, we get a significantly better fit by including an additional, low-temperature thermal Comptonization component, which allows a much lower black hole spin. Corroboration of the existence of an additional Compton component comes from the frequency-dependent hard lags seen in the rapid variability in archival high/soft state data. These cannot be explained if the continuum is a single non-thermal Comptonization component, but are instead consistent with a radially stratified, multi-zone Comptonization spectrum, where the spectrum is softer further from the black hole. A complex multi-zone Comptonization continuum is required to explain both spectra and timing together, and this has an impact on the derived black hole spin.

  8. X-ray Studies of the Black Hole Binary Cygnus X-1 with Suzaku

    NASA Astrophysics Data System (ADS)

    Yamada, Shin'ya

    2011-03-01

    In order to study X-ray properties of black hole binaries in so-called Low/Hard state, we analyzed 0.5--300 keV data of Cyg X-1, taken with the X-ray Imaging Spectrometer and the Hard X-ray Detector onboard the X-ray satellite Suzaku. The data were acquired on 25 occasions from 2005 to 2009, with a total exposure of ~450 ks. The source was in the Low/Hard state throughout, and the 0.5-300 keV luminosity changed by a factor of 4, corresponding to 2-10% of the Eddington limit for a 10 Mo black hole. Among the 25 data sets, the first one was already analyzed by Makishima et al. (2008), who successfully reproduced the wide-band spectrum by a linear combination of an emission from a standard accretion disk, soft and hard Comptonization continua, and reprocessed features. Given this, we analyzed the 25 data sets for intensity-related spectral changes, on three different time scales using different analysis methods. One is the source behavior on time scales of days to months, studied via direct comparison among the 25 spectra which are averaged over individual observations. Another is spectral changes on time scales of 1-2 seconds, revealed through ``intensity-sorted spectroscopy''. The other is spectral changes on time scales down to ~0.1 seconds, conducted using ``shot analysis" technique which was originally developed by Negoro et al. (1997) with Ginga. These studies partially incorporated spectral fitting in terms of a thermal Comptonization model. We payed great attention to instrumental problems caused by the source brightness, and occasional ``dipping" episodes which affects the Cyg X-1 spectrum at low energies. The shot analysis incorporated a small fraction of XIS data that were taken in the P-sum mode with a time resolution of 7.8 msec. Through these consistent analyses of all the 25 data sets, we found that a significant soft X-ray excess develops as the source gets brighter. Comparing results from the different time scales, the soft excess was further

  9. The Soft Gamma-Ray Spectral Variability of Cygnus X-1

    NASA Astrophysics Data System (ADS)

    McConnell, M. L.; Zdziarski, A. A.; Bennett, K.; Bloemen, H.; Collmar, W.; Hermsen, W.; Kuiper, L.; Paciesas, W.; Phlips, B. F.; Poutanen, J.; Ryan, J. M.; Schönfelder, V.; Steinle, H.; Strong, A. W.

    2002-06-01

    We have used observations of Cyg X-1 from the Compton Gamma Ray Observatory and BeppoSAX to study the variation in the MeV γ-ray emission between the hard and soft spectral states, using spectra that cover the energy range from 20 keV up to 10 MeV. These data provide evidence for significant spectral variability at energies above 1 MeV. In particular, whereas the hard X-ray flux decreases during the soft state, the flux at energies above 1 MeV increases, resulting in a significantly harder γ-ray spectrum at energies above 1 MeV. This behavior is consistent with the general picture of galactic black hole candidates having two distinct spectral forms at soft γ-ray energies. These data extend this picture, for the first time, to energies above 1 MeV. We have used two different hybrid thermal/nonthermal Comptonization models to fit broadband spectral data obtained in both the hard and soft spectral states. These fits provide a quantitative estimate of the electron distribution and allow us to probe the physical changes that take place during transitions between the low and high X-ray states. We find that there is a significant increase (by a factor of ~4) in the bolometric luminosity as the source moves from the hard state to the soft state. Furthermore, the presence of a nonthermal tail in the Comptonizing electron distribution provides significant constraints on the magnetic field in the source region.

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

    SciTech Connect

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

    2013-04-20

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

  11. Monitoring the 2010-2015 Hard X-ray/Low-Energy Gamma-Ray Activity of Cygnus X-1 with GBM

    NASA Astrophysics Data System (ADS)

    Case, Gary L.; Jenke, Peter; Wilson-Hodge, Colleen A.

    2017-08-01

    Cygnus X-1 is a high-mass X-ray binary with a black hole companion that typically resides in a hard spectral state, where it is extremely bright in hard X-rays and low energy gamma rays and much fainter in the soft X-rays. Since 2008 August, we have used the Gamma-Ray Burst Monitor (GBM) on Fermi to monitor Cyg X-1 in the 10-1000 keV energy range using the Earth occultation technique. Starting in the middle of 2010, Cyg X-1 was observed by GBM to enter a period of increased activity, making several transitions to the soft state, characterized by the typical rise in the soft X-ray flux and decrease in the hard x-ray and low energy gamma-ray flux. From the soft state, Cyg X-1 made several transitions to intermediate states as well as several short transitions back to the hard state. At the end of 2015, Cyg X-1 transitioned back to the canonical hard state, where it has remained ever since. We have generated long-term, broad-band light curves based on daily monitoring of Cyg X-1 over a 9 year period showing the hard-to-soft state transitions, the intermediate states, and the soft-to-hard and failed soft-to-hard state transitions. Spectra are presented of Cyg X-1 in the various states and comparisons made between spectra in the same state. The time evolution of the x-ray hardness ratios is also presented.

  12. 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.

  13. 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.

  14. 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.

  15. Corona, Jet, and Relativistic Line Models for Suzaku/RXTE/Chandra-HETG Observations of the Cygnus X-1 Hard State

    NASA Astrophysics Data System (ADS)

    Nowak, Michael A.; Hanke, Manfred; Trowbridge, Sarah N.; Markoff, Sera B.; Wilms, Jörn; Pottschmidt, Katja; Coppi, Paolo; Maitra, Dipankar; Davis, John E.; Tramper, Frank

    2011-02-01

    Using Suzaku and the Rossi X-ray Timing Explorer (RXTE), we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard "low states." Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source passing through the dense phases of the "focused wind" from the mass donating secondary. One of our observations was also simultaneous with observations by the Chandra-High Energy Transmission Grating (HETG). These latter spectra are crucial for revealing the ionized absorption due to the secondary's focused wind. Such absorption is present and must be accounted for in all four spectra. These simultaneous data give an unprecedented view of the 0.8-300 keV spectrum of Cyg X-1, and hence bear upon both corona and X-ray emitting jet models of black hole hard states. Three models fit the spectra well: coronae with thermal or mixed thermal/non-thermal electron populations and jets. All three models require a soft component that we fit with a low temperature disk spectrum with an inner radius of only a few tens of GM/c 2. All three models also agree that the known spectral break at 10 keV is not solely due to the presence of reflection, but each gives a different underlying explanation for the augmentation of this break. Thus, whereas all three models require that there is a relativistically broadened Fe line, the strength and inner radius of such a line is dependent upon the specific model, thus making premature line-based estimates of the black hole spin in the Cyg X-1 system. We look at the relativistic line in detail, accounting for the narrow Fe emission and ionized absorption detected by HETG. Although the specific relativistic parameters of the line are continuum dependent, none of the broad line fits allow for an inner disk radius that is >40 GM/c 2.

  16. Corona, Jet, and Relativistic Line Models for Suzaku/RXTE/Chandra-HETG Observations of the Cygnus X-1 Hard State

    NASA Technical Reports Server (NTRS)

    Nowak, Michael A.; Hanke, Manfred; Trowbridge, Sarah N.; Markoff, Sera B.; Wilms, Joern; Pottschmidt, Katja; Coppi, Paolo; Maitra, Dipankar; Davis, Jhn E.; Tramper, Frank

    2009-01-01

    Using Suzaku and the Rossi X-ray Timing Explorer (RXTE), we have conducted a series of four simultaneous observations of the galactic black hole candidate Cyg X-1 in what were historically faint and spectrally hard "low states". Additionally, all of these observations occurred near superior conjunction with our line of sight to the X-ray source passing through the dense phases of the "focused wind" from the mass donating secondary. One of our observations was also simultaneous with observations by the Chandra-High Energy Transmission Grating (HETG). These latter spectra are crucial for revealing the ionized absorption due to the secondary s focused wind. Such absorption is present and must be accounted for in all four spectra. These simultaneous data give an unprecedented view of the 0.8-300 keV spectrum of Cyg X-1, and hence bear upon both corona and X-ray emitting jet models of black hole hard states. Three models fit the spectra well: coronae with thermal or mixed thermal/non-thermal electron populations, and jets. All three models require a soft component that we fit with a low temperature disk spectrum with an inner radius of only a few tens of GM/c2. All three models also agree that the known spectral break at 10 keV is not solely due to the presence of reflection, but each gives a different underlying explanation for the augmentation of this break. Thus whereas all three models require that there is a relativistically broadened Fe line, the strength and inner radius of such a line is dependent upon the specific model, thus making premature line-based estimates of the black hole spin in the Cyg X-1 system. We look at the relativistic line in detail, accounting for the narrow Fe emission and ionized absorption detected by HETG. Although the specific relativistic parameters of the line are continuum-dependent, none of the broad line fits allow for an inner disk radius that is > 40 GM/c(sup 2).

  17. Revealing the broad iron Kα line in Cygnus X-1 through simultaneous XMM-Newton, RXTE, and INTEGRAL observations

    NASA Astrophysics Data System (ADS)

    Duro, Refiz; Dauser, Thomas; Grinberg, Victoria; Miškovičová, Ivica; Rodriguez, Jérôme; Tomsick, John; Hanke, Manfred; Pottschmidt, Katja; Nowak, Michael A.; Kreykenbohm, Sonja; Cadolle Bel, Marion; Bodaghee, Arash; Lohfink, Anne; Reynolds, Christopher S.; Kendziorra, Eckhard; Kirsch, Marcus G. F.; Staubert, Rüdiger; Wilms, Jörn

    2016-05-01

    We report on the analysis of the broad Fe Kα line feature of Cyg X-1 in the spectra of four simultaneous hard intermediate state observations made with the X-ray Multiple Mirror mission (XMM-Newton), the Rossi X-ray Timing Explorer (RXTE), and the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). The high quality of the XMM-Newton data taken in the Modified Timing Mode of the EPIC-pn camera provides a great opportunity to investigate the broadened Fe Kα reflection line at 6.4 keV with a very high signal to noise ratio. The 4-500 keV energy range is used to constrain the underlying continuum and the reflection at higher energies. We first investigate the data by applying a phenomenological model that consists of the sum of an exponentially cutoff power law and relativistically smeared reflection. Additionally, we apply a more physical approach and model the irradiation of the accretion disk directly from the lamp post geometry. All four observations show consistent values for the black hole parameters with a spin of a ~ 0.9, in agreement with recent measurements from reflection and disk continuum fitting. The inclination is found to be i ~ 30°, consistent with the orbital inclination and different from inclination measurements made during the soft state, which show a higher inclination. We speculate that the difference between the inclination measurements is due to changes in the inner region of the accretion disk.

  18. Orbital modulations of X-ray light curves of Cygnus X-1 in its low/hard and high/soft states

    NASA Astrophysics Data System (ADS)

    Sugimoto, Juri; Kitamoto, Shunji; Mihara, Tatehiro; Matsuoka, Masaru

    2017-06-01

    The black hole binary Cygnus X-1 has a 5.6-d orbital period. We first detected a clear intensity modulation with the orbital period in its high/soft state with six-year MAXI data, as well as in its low/hard state. In the low/hard state, the folded light curves showed an intensity drop at the superior conjunction of the black hole by a modulation factor (MF), which is the amplitude divided by the average, of 8 ± 1%, 4 ± 1%, and 3 ± 2% for 2-4, 4-10, and 10-20 keV bands, respectively, showing a spectral hardening at the superior conjunction of the black hole. Spectral analysis in the low/hard state, with a model consisting of a power law and a photoelectric absorption, showed that the hydrogen column density, NH, increased from (2.9 ± 0.4) × 1021 cm-2 to (4.7 ± 1.1) × 1021 cm-2 around the superior conjunction. The flux of the power-law component decreased by 6 ± 1%. On the other hand, MFs for the folded light curves in the high/soft state, were 4 ± 1% and 4 ± 2% for the 2-4 keV and 4-10 keV bands, respectively. We applied a model consisting of a power law and a disk blackbody with a photoelectric absorption. A modulation of the flux of the power-law component was found to be 7 ± 5% in MF, while the modulation of NH was less than 1 × 1021 cm-2. These results can be interpreted as follows: the modulation of both states can be mainly explained by scattering of X-rays by an ionized stellar wind, but, only at the superior conjunction in the low/hard state, a large photoelectric absorption appears because of the low ionization state of the wind in the line of sight at phase 0. Such a condition can be established by reasonable parameters of an inhomogeneous wind and the observed luminosities.

  19. Studying microquasars with IXPE

    NASA Astrophysics Data System (ADS)

    Matt, Giorgio

    2017-08-01

    While timing and spectroscopy of microquasars are well established techniques, X-ray polarimetry is lagging behind, despite its widely recognized importance in providing vital information on the phsyics and geometry of these sources, including strong gravity effects. Happily, this will change very soon thanks to the approval by NASA of IXPE (the Imaging X-ray Polarimetry Explorer), the next mission inthe SMEX program, to be launched in 2020.In this contribution, the main scientific results expected by IXPE on microquasars will be discussed, with particular emphasys on the possibility to measure the black hole spin via energy-dependent polarization observations.

  20. Cygnus unberth

    NASA Image and Video Library

    2016-02-19

    ISS046e043433 (02/19/2016) --- The Expedition 46 crew took out the trash recently when it released the Orbital ATK Cygnus spacecraft from the grips of the International Space Station’s Canadarm2 robotic arm. Cygnus was filled with roughly 1.5 tons of trash and discarded gear before the hatches were closed. Ground controllers then remotely guided the Canadarm2 to grapple Cygnus and detach it from the Unity module. NASA astronauts Scott Kelly and Tim Kopra commanded the Canadarm2 to release Cygnus Feb 19, at 7:26 a.m. EST when it began gracefully departing the vicinity of the station. Cygnus ultimately burned up during reentry through the Earth’s atmosphere on Saturday, Feb 20. This was Orbital ATK’s fourth commercial resupply mission.

  1. 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).

  2. 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

  3. 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.

  4. INTEGRAL SPI Observations of Cygnus X-1 in the Soft State: What about the Jet Contribution in Hard X-Rays?

    NASA Astrophysics Data System (ADS)

    Jourdain, E.; Roques, J. P.; Chauvin, M.

    2014-07-01

    During the first 7 yr of the INTEGRAL mission (2003-2009), Cyg X-1 has essentially been detected in its hard state (HS), with some incursions in intermediate HSs. This long, spectrally stable period allowed in particular the measurement of the polarization of the high-energy component that has long been observed above 200 keV in this peculiar object. This result strongly suggests that here we see the contribution of the jet, known to emit a strong synchrotron radio emission. In 2010 June, Cyg X-1 underwent a completed transition toward a soft state (SS). It gave us the unique opportunity to study in detail the corona emission in this spectral state, and to investigate in particular the behavior of the jet contribution. Indeed, during the SS, the hard X-ray emission decreases drastically, with its maximum energy shifted toward lower energy and its flux divided by a factor of ~5-10. Interestingly, the radio emission follows a similar drop, supporting the correlation between the jet emission and the hard component, even though the flux is too low to quantify the polarization characteristics. Based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Spain, and Switzerland), the Czech Republic and Poland with the participation of Russia and USA.

  5. INTEGRAL SPI observations of Cygnus X-1 in the soft state: What about the jet contribution in hard X-rays?

    SciTech Connect

    Jourdain, E.; Roques, J. P.; Chauvin, M.

    2014-07-01

    During the first 7 yr of the INTEGRAL mission (2003-2009), Cyg X-1 has essentially been detected in its hard state (HS), with some incursions in intermediate HSs. This long, spectrally stable period allowed in particular the measurement of the polarization of the high-energy component that has long been observed above 200 keV in this peculiar object. This result strongly suggests that here we see the contribution of the jet, known to emit a strong synchrotron radio emission. In 2010 June, Cyg X-1 underwent a completed transition toward a soft state (SS). It gave us the unique opportunity to study in detail the corona emission in this spectral state, and to investigate in particular the behavior of the jet contribution. Indeed, during the SS, the hard X-ray emission decreases drastically, with its maximum energy shifted toward lower energy and its flux divided by a factor of ∼5-10. Interestingly, the radio emission follows a similar drop, supporting the correlation between the jet emission and the hard component, even though the flux is too low to quantify the polarization characteristics.

  6. On the Nature of the Variability Power Decay toward Soft Spectral States in X-Ray Binaries: Case Study in Cygnus X-1

    NASA Astrophysics Data System (ADS)

    Titarchuk, Lev; Shaposhnikov, Nikolai

    2008-05-01

    A characteristic feature of the Fourier power density spectrum (PDS) observed from black hole X-ray binaries in low/hard and intermediate spectral states is a broadband-limited noise characterized by a constant below some frequency (a "break" frequency) and a power law above this frequency. It has been shown that the variability of this type can be produced by the inward diffusion of the local driving perturbations in a bounded configuration (accretion disk or corona). In the framework of this model, the perturbation diffusion time t0 is related to the phenomenological break frequency, while the PDS power-law slope above the "break" is determined by the viscosity distribution over the configuration. The perturbation diffusion scenario explains the decay of the power of X-ray variability observed in a number of compact sources (containing black holes and neutron stars) during an evolution of these sources from low/hard to high/soft states. We compare the model predictions with the subset of data from Cyg X-1 collected by the Rossi X-Ray Time Explorer (RXTE). Our extensive analysis of the Cyg X-1 PDSs demonstrates that the observed integrated power Px decreases approximately as the square root of the characteristic frequency of the driving oscillations νdr. The RXTE observations of Cyg X-1 allow us to infer Pdr and t0 as a function of νdr. Using the inferred dependences of the integrated power of the driving oscillations Pdr and t0 on νdr we demonstrate that the power predicted by the model also decays as Px,diff propto ν-0.5dr, which is similar to the observed Px behavior. We also apply the basic parameters of observed PDSs, power-law indices, and low-frequency quasi-periodic oscillations to infer the Reynolds number (Re) from the observations using the method developed in our previous paper. Our analysis shows that Re increases from values of about 10 in low/hard state to about 70 during the high/soft state.

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

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

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

  8. Cygnus Arrival

    NASA Image and Video Library

    2014-01-12

    ISS038-E-031969 (12 Jan. 2014) --- At the windows in the International Space Station's Cupola, NASA astronaut Rick Mastracchio, Expedition 38 flight engineer, uses a laser range finder during rendezvous, capture and berthing operations with the Orbital Sciences Corp. Cygnus commercial cargo craft.

  9. Cygnus Capture

    NASA Image and Video Library

    2014-01-12

    ISS038-E-027441 (12 Jan. 2014) --- The Orbital Sciences Corp. Cygnus commercial cargo craft is photographed by an Expedition 38 crew member on the International Space Station during rendezvous and berthing operations on Jan. 12, 2014. A blue and white part of Earth provides the backdrop for the scene.

  10. Understanding the Long-Term Spectral Variability of Cygnus X-1 with Burst and Transient Source Experiment and All-Sky Monitor Observations

    NASA Technical Reports Server (NTRS)

    Zdziarski, Andrzej A.; Poutanen, Juri; Paciesas, William S.; Wen, Lin-Qing

    2002-01-01

    We present a comprehensive analysis of all observations of Cyg X-1 by the Compton Gamma Ray Observatory Burst and Transient Source Experiment (BATSE; 20-300 keV) and by the Rossi X-Ray Timing Explorer all-sky monitor (ASM; 1.5-12 keV) until 2002 June, including approximately 1200 days of simultaneous data. We find a number of correlations between fluxes and hardnesses in different energy bands. 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 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 20-100 keV flux. 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. There is also 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 superposed on a constant soft blackbody component. These variability patterns are in agreement with the dependencies of the rms variability on the photon energy in the two states. We also study in detail recent soft states from late 2000 until 2002. The last of them has lasted thus far for more than 200 days. Their spectra are generally harder in the 1.5-5 keV band and similar or softer in the 3-12 keV band than the spectra of the 1996 soft state, whereas the rms variability is stronger in all the ASM bands. On the other hand, the 1994 soft state transition observed by BATSE appears very similar to the 1996 one. We interpret the variability patterns in terms of theoretical Comptonization

  11. New evidence for extreme particle acceleration in microquasars

    NASA Astrophysics Data System (ADS)

    Striani, E.; Tavani, M.; Bulgarelli, A.; Piano, G.; Sabatini, S.

    Microquasars are binary systems consisting of a neutron star or stellar-mass black hole accreting gas from a companion star and producing relativistic jets. Here we report the AGILE detections of gamma -ray emission from the microquasars Cyg X-1 and Cyg-3 between 100 MeV and 3 GeV. A significant transient gamma-ray emission was detected on 2009, October 16, during a spectral ``hard state" of Cyg X-1. This shows that extreme particle acceleration can occasionally occur in microquasars also in the hard state, for which a spectral cutoff above 1 MeV is predicted by theoretical models. No persistent emission was found for Cyg X-1 integrating all our data accumulated in the period between 2007 July and 2009 October, during which the source was in the hard state, confirming the overall spectral cutoff above 1 MeV. Several flaring episodes were instead detected for Cyg X-3 following a repetitive pattern. The gamma -ray emission detected by AGILE always occured while the source was in the ``soft state", and always preceding a major radio flare. These gamma -ray intense flares thus turn out to occur during the preparation and energy charging before the plasmoid energization and ejection.

  12. Cygnus Capture

    NASA Image and Video Library

    2016-03-26

    ISS047e021823 (03/26/2016) --- The Orbital ATK Cygnus cargo ship is seen on final approach to the International Space Station. The vehicle was captured at 6:51 a.m. EDT March 26 using the space station's Canadarm2 robotic arm by Expedition 47 Commander Tim Kopra. The unmanned cargo craft was then bolted to the Earth-facing port on the Unity module at 10:52 a.m. Orbital ATK’s fifth cargo delivery flight under its Commercial Resupply Services contract delivered over 7,700 pounds of cargo and included equipment to support some 250 experiments during Expeditions 47 and 48.

  13. Multi-wavelength Observations of Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Varlotta, Angelo; VERITAS

    2011-09-01

    Cygnus X-3 is a X-ray binary system containing a stellar-mass black hole and a Wolf-Rayet companion star with prominent jets, placing it in the sub-category of microquasars. Due to their similarities with AGN and GRBs, they are thought to be possible gamma-ray emitters, as the recent Fermi LAT detection has proven. We have carried out VERITAS observations on this source to find a link between the hard X-ray, GeV gamma-ray and TeV gamma-ray emissions. These observations have been triggered on the recent AGILE and Swift ATels, respectively ATel #3386 and ATel #3439. This result aims to shed light on the mechanisms of particle acceleration and gamma-ray emission in microquasars within the high-energy multi-wavelength context.

  14. Cygnus X-3 Returns to an Active State

    NASA Astrophysics Data System (ADS)

    McCollough, Michael L.; Koljonen, Karri; Gurwell, Mark A.; Trushkin, Sergei; Pooley, Guy G.

    2017-08-01

    Cygnus X-3 is a well-known microquasar composed of a mass-donating Wolf-Rayet star and a compact object. Recently, Cygnus X-3 has been in a quiescent state for an extended period of time (2011-2016) but returned to an active state on two occasions during 2016/2017 including quenched/hypersoft states, gamma-ray emission, and major radio flares. During these two periods of activity, we undertook multi-wavelength observing campaigns with observations in the radio (RATAN-600, AMI-LA, Metsähovi), submillimeter (SMA, EHT), X-ray (Swift/XRT, MAXI), hard X-ray (Swift/BAT, NuSTAR), and gamma-ray (AGILE, Fermi, VERITAS). At the peak of the major radio flare in April 2017 observations were made with VERITAS (TeV), NuSTAR (hard X-ray), and the Event Horizon Telescope (submillimeter). In this presentation, I will review these observing campaigns and the insights they provide about Cygnus X-3.

  15. Black hole binaries and microquasars

    NASA Astrophysics Data System (ADS)

    Zhang, Shuang-Nan

    2013-12-01

    This is a general review on the observations and physics of black hole X-ray binaries and microquasars, with the emphasize on recent developments in the high energy regime. The focus is put on understanding the accretion flows and measuring the parameters of black holes in them. It includes mainly two parts: i) Brief review of several recent review article on this subject; ii) Further development on several topics, including black hole spin measurements, hot accretion flows, corona formation, state transitions and thermal stability of standard think disk. This is thus not a regular bottom-up approach, which I feel not necessary at this stage. Major effort is made in making and incorporating from many sources useful plots and illustrations, in order to make this article more comprehensible to non-expert readers. In the end I attempt to make a unification scheme on the accretion-outflow (wind/jet) connections of all types of accreting BHs of all accretion rates and all BH mass scales, and finally provide a brief outlook.

  16. 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.

  17. 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.

  18. Gamma-Ray Emission from Microquasars

    NASA Astrophysics Data System (ADS)

    Kaufman Bernado, M. M.

    2005-04-01

    Microquasars, X-ray binary systems that generate relativistic jets, were discovered in our Galaxy in the last decade of the XXth century. Their name indicates that they are manifestations of the same physics as quasars but on a completely different scale. Parallel to this discovery, the EGRET instrument on board of the Compton Gamma Ray Observatory detected 271 point like gamma-ray sources 170 of which were not clearly identified with known objects. This marked the beginning of gamma-ray source population studies in the Galaxy. We present in this thesis models for gamma-ray production in microquasars with the aim to propose them as possible parent populations for different groups of EGRET unidentified sources. These models are developed for a variety of scenarios taking into account several possible combinations, i.e. black holes or neutron stars as the compact object, low mass or high mass stellar companions, as well as leptonic or hadronic gamma-ray production processes. We also show that the presented models for gamma-rays emitting microquasars can be used to explain observations from well known sources that are detected in energy ranges other than EGRET's. Finally, we include an alternative gamma-ray producing situation that does not involve microquasars but a specific unidentified EGRET source possibly linked to a magnetized accreting pulsar.

  19. "Microquasar" Discoveries Win Prize for Astronomers

    NASA Astrophysics Data System (ADS)

    The discovery of "microquasars" within our own Milky Way Galaxy has won two astronomers a prize from the High Energy Astrophysics Division of the American Astronomical Society. Felix Mirabel of the Center for Studies at Saclay, France, and Luis Rodriguez of the Institute of Astronomy at the National Autonomous University in Mexico City, were awarded the Bruno Rossi Prize at the American Astronomical Society meeting in Toronto, Ontario, today. The two researchers, who have collaborated for more than 15 years, used an orbiting X-Ray observatory and the National Science Foundation's Very Large Array (VLA) radio telescope to discover the extremely energetic microquasars. Microquasars are thought to be binary-star systems with one of the stars either a superdense neutron star or a black hole. They emit X-rays and eject jets of subatomic particles at speeds approaching that of light. Though the neutron stars or black holes in microquasars are only a few times the mass of the sun, the phenomena associated with them, such as the jets, are similar to those seen in active galaxies and quasars, believed to be powered by the gravitational energy of black holes with millions of times the mass of the sun. As such, the microquasars provide much closer "laboratories" for study of these phenomena, which remain poorly understood. The Rossi Prize is awarded for "a significant contribution to high energy astrophysics, with particular emphasis on recent work," according to the High Energy Astrophysics Division. Mirabel and Rodriguez began the research that led to the microquasar discoveries in 1990. Using the French-Russian SIGMA- GRANAT X-Ray satellite, they discovered a microquasar near the Milky Way's center in 1992. With the VLA, they found radio emission from this object. In 1992, using the same satellite, they discovered a similar object, called GRS 1915+105. In 1994, that object experienced an outburst that made it bright enough at radio wavelengths to observe with the VLA

  20. Prospects for Observations of Microquasars with GLAST

    SciTech Connect

    Dubois, Richard; /SLAC

    2007-10-09

    The Gamma-ray Large Area Space Telescope (GLAST) is a next generation high energy gamma-ray observatory due for launch in Fall 2007. The primary instrument is the Large Area Telescope (LAT), which will measure gamma-ray flux and spectra from 20 MeV to > 300 GeV and is a successor to the highly successful EGRET experiment on CGRO. The LAT will have better angular resolution, greater effective area, wider field of view and broader energy coverage than any previous experiment in this energy range. This poster will present performance estimates with particular emphasis on how these apply to studies of microquasars. The LAT's scanning mode will provide unprecedented uniformity of sky coverage and permit measurements of light curves for any source. We will show results from recent detailed simulations that illustrate the potential of the LAT to observe microquasar variability and spectra, including source sensitivity and ability to detect orbital modulation.

  1. SAS 3 observations of Cygnus X-1 - The intensity dips

    NASA Technical Reports Server (NTRS)

    Remillard, R. A.; Canizares, C. R.

    1984-01-01

    In general, the dips are observed to occur near superior conjunctions of the X-ray source, but one pair of 2-minute dips occurs when the X-ray source is closer to the observer than is the supergiant companion. The dips are analyzed spectrally with the aid of seven energy channels in the range 1.2-50 keV. Essentially, there is no change in the spectral index during the dips. Reductions in the count rates are observed at energies exceeding 6 keV for some of the dips, but the dip amplitude is always significantly greater in the 1.2-3 keV band. It is believed that absorption by partially ionized gas may best explain these results, since the observations of Pravdo et al. (1980) rule out absorption by unionized material. Estimates for the intervening gas density, extent, and distance from the X-ray source are presented. Attention is also given to the problems confronting the models for the injection of gas through the line of sight, believed to be inclined by approximately 30 deg from the binary pole.

  2. Cygnus Diverter Switch Analysis

    DTIC Science & Technology

    2007-06-01

    Nuclear Security Administration under contract DE-AC04-94AL85000. ξ email : eormond@sandia.gov Abstract The Cygnus Dual Beam Radiographic...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...water-filled pulse-forming line (PFL), waterfilled coaxial transmission line (WTL), 3-cell inductive voltage adder (IVA), and rod-pinch diode. The

  3. 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.

  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. Cygnus Performance in Subcritical Experiments

    DTIC Science & Technology

    2007-06-01

    thermoluminescent dosimeters (TLDs). Note the high degree of similarity in performance between the two machines. Figure 2. Sample diode and x-ray... thermoluminescent dosimeters: (top to bottom) Armando, Step Wedge, Thermos, and All Shots. Data for Cygnus 1 (red circles), and Cygnus 2 (blue

  6. An INTEGRAL Archival Search for Microquasar Candidates

    NASA Astrophysics Data System (ADS)

    Walker, L. M.; Larson, K. L.; Boone, L. M.

    2005-12-01

    We present the status of an ongoing effort to complete a systematic search of the INTEGRAL archive for possible microquasar candidates. Source screening follows the methodology of Motch et al. (1998), but employs current versions of the NRAO/VLA and X-ray catalogs for positional cross--correlation studies. Candidate source fluxes are evaluated with respect to the sensitivities of the the instruments on board the INTEGRAL satellite, and a preliminary analysis of ISGRI and JEM--X data for appropriate candidate sources is presented. This work was funded in part by The College of Wooster's NSF supported REU program (DMR-0243811).

  7. 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.

  8. Nature of NML Cygnus

    SciTech Connect

    Morris, M.; Jura, M.

    1983-04-01

    We suggest that H II region observed near NML Cygnus, a highly evolved mass-losing giant, results from the photoionization of the outflow by the luminous, hot stars in the Cyg OB2 association. NML Cyg is at a projected distance of 100 pc from Cyg OB2, but because all of these objects are near the center of the X-ray emitting superbubble in Cygnus where the hydrogen is mostly ionized, the Lyman continuum photons probably can travel this far without appreciable absorption. The observed structure of the H II region matches this hypothesis quite well. This picture provides the first reasonably precise estimate of the distance to NML Cyg: 2 kpc. At this distance, the star has a luminosity of 5 x 10/sup 5/ L/sub sun/ and a minimum mass loss rate of 6.4 x 10/sup -5/ M/sub sun/ yr/sup -1/. We conclude that NML Cyg is a massive (50 M/sub sun/) star in a highly evolved state. It is likely that it will soon become a supernova and contribute to the general expansion of the superbubble. Before doing so, however, it may endure a phase as a W-R star. If it remains a mass-losing supergiant when it does explode, there may be enough dust around it that it would be optically inconspicuous even if interstellar extinction were negligible. The possiblity that infrared supernovae are common would be very important for understanding the rate of stellar explosions, the formation of pulsars, and nucleosynthesis in the Galaxy.

  9. Tour the Cygnus X Star Factory

    NASA Image and Video Library

    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...

  10. X-ray jets in microquasar

    NASA Astrophysics Data System (ADS)

    Corbel, S.

    2003-03-01

    Large scale moving relativistic X-ray jets have been recently discovered around the microquasar XTE J1550--564 (Corbel et al. 2002, Sci., 298, 196). They have been observed over a timescale of at least four years. The broadband spectra of the jets are consistent with synchrotron emission from high energy (up to 10 TeV) particles accelerated in shocks, possibly during the interaction of the jets with the interstellar medium. XTE J1550-564 offers a unique opportunity to study the dynamical evolution of relativistic jets on time scales inaccessible for active galactic nuclei jets, with implications for our understanding of relativistic jets from Galactic x-ray binaries and active galactic nuclei. New results from the continuing multiwavelength campaign, as well as a comparison with other jet producing system, will be shown during this presentation.

  11. GLAST Status and Application to Microquasars

    SciTech Connect

    Dubois, Richard; /SLAC

    2006-11-15

    The Gamma-ray Large Area Space Telescope (GLAST) is a next generation high energy gamma-ray observatory due for launch in Fall 2007. The primary instrument is the Large Area Telescope (LAT), which will measure gamma-ray flux and spectra from 20 MeV to > 300 GeV and is a successor to the highly successful EGRET experiment on CGRO. The LAT will have better angular resolution, greater effective area, wider field of view and broader energy coverage than any previous experiment in this energy range. An overview of the LAT instrument design and construction is presented which includes performance estimates with particular emphasis on how these apply to studies of microquasars. The nature and quality of the data that will be provided by the LAT is described with results from recent detailed simulations that illustrate the potential of the LAT to observe gamma ray variability and spectra.

  12. 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.

  13. Bagging of OA-7 CYGNUS

    NASA Image and Video Library

    2017-02-21

    In the Space Station Processing Facility high bay at NASA's Kennedy Space Center in Florida, technicians assist as a crane is used to lower a protective covering around Orbital ATK's CYGNUS pressurized cargo module. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on March 19, 2017. CYGNUS will deliver thousands of pounds of supplies, equipment and scientific research materials to the space station.

  14. Bagging of OA-7 CYGNUS

    NASA Image and Video Library

    2017-02-21

    In the Space Station Processing Facility high bay at NASA's Kennedy Space Center in Florida, technicians secure a protective covering around Orbital ATK's CYGNUS pressurized cargo module. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on March 19, 2017. CYGNUS will deliver thousands of pounds of supplies, equipment and scientific research materials to the space station.

  15. Bagging of OA-7 CYGNUS

    NASA Image and Video Library

    2017-02-21

    In the Space Station Processing Facility high bay at NASA's Kennedy Space Center in Florida, technicians are preparing to assist as a crane is used to lower a protective covering around Orbital ATK's CYGNUS pressurized cargo module. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on March 19, 2017. CYGNUS will deliver thousands of pounds of supplies, equipment and scientific research materials to the space station.

  16. Bagging of OA-7 CYGNUS

    NASA Image and Video Library

    2017-02-21

    In the Space Station Processing Facility high bay at NASA's Kennedy Space Center in Florida, technicians position a protective covering around Orbital ATK's CYGNUS pressurized cargo module. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on March 19, 2017. CYGNUS will deliver thousands of pounds of supplies, equipment and scientific research materials to the space station.

  17. Bagging of OA-7 CYGNUS

    NASA Image and Video Library

    2017-02-21

    In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, a KAMAG transporter has arrived in the high bay. Technicians are preparing the protective covering for Orbital ATK's CYGNUS pressurized cargo module. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on March 19, 2017. CYGNUS will deliver thousands of pounds of supplies, equipment and scientific research materials to the space station.

  18. SPI/INTEGRAL observation of the Cygnus region

    NASA Astrophysics Data System (ADS)

    Bouchet, L.; Jourdain, E.; Roques, J. P.; Mandrou, P.; von Ballmoos, P.; Boggs, S.; Caraveo, P.; Cassé, M.; Cordier, B.; Diehl, R.; Durouchoux, P.; von Kienlin, A.; Knodlseder, J.; Jean, P.; Leleux, P.; Lichti, G. G.; Matteson, J.; Sanchez, F.; Schanne, S.; Schoenfelder, V.; Skinner, G.; Strong, A.; Teegarden, B.; Vedrenne, G.; Wunderer, C.

    2003-11-01

    We present the analysis of the first observations of the Cygnus region by the SPI spectrometer onboard the Integral Gamma Ray Observatory, encompassing ~600 ks of data. Three sources namely Cyg X-1, Cyg X-3 and EXO 2030+375 were clearly detected. Our data illustrate the temporal variability of Cyg X-1 in the energy range from 20 keV to 300 keV. The spectral analysis shows a remarkable stability of the Cyg X-1 spectra when averaged over one day timescale. The other goal of these observations is SPI inflight calibration and performance verification. The latest objective has been achieved as demonstrated by the results presented in this paper.

  19. Absorption of high-energy gamma rays in Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Cerutti, B.; Dubus, G.; Malzac, J.; Szostek, A.; Belmont, R.; Zdziarski, A. A.; Henri, G.

    2011-05-01

    Context. The microquasar Cygnus X-3 was detected at high energies by the gamma-ray space telescopes AGILE and Fermi. The gamma-ray emission is transient, modulated with the orbital period and seems related to major radio flares, i.e. to the relativistic jet. The GeV gamma-ray flux can be substantially attenuated by internal absorption with the ambient X-rays. Aims: We examine quantitatively the effect of pair production in Cygnus X-3 and put constraints on the location of the gamma-ray source. Methods: Cygnus X-3 exhibits complex temporal and spectral patterns in X-rays. During gamma-ray flares, the X-ray emission can be approximated by a bright disk black-body component and a non-thermal tail extending in hard X-rays, which is possibly related to a corona above the disk. We calculate numerically the exact optical depth for gamma rays above a standard accretion disk. Emission and absorption in the corona are also investigated. Results: GeV gamma rays are significantly absorbed by soft X-rays emitted from the inner parts of the accretion disk. The absorption pattern is complex and anisotropic. Isotropization of X-rays caused by Thomson scattering in the companion-star wind tends to increase the gamma-ray opacity. Gamma rays from the corona suffer from strong absorption by photons from the disk and cannot explain the observed high-energy emission, unless the corona is unrealistically extended. Conclusions: The lack of an absorption feature in the GeV emission indicates that high-energy gamma rays should be located at a minimum distance ~108-1010 cm from the compact object. The gamma-ray emission is unlikely to have a coronal origin.

  20. 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)

  1. 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)

  2. NGC 300 X-1 and IC 10 X-1: a new breed of black hole binary?

    NASA Astrophysics Data System (ADS)

    Barnard, R.; Clark, J. S.; Kolb, U. C.

    2008-09-01

    Context: IC 10 X-1 has recently been confirmed as a black hole (BH) + Wolf-Rayet (WR) X-ray binary, and NGC 300 X-1 is thought to be. The only other known BH+WR candidate is Cygnus X-3. IC 10 X-1 and NGC 300 X-1 have similar X-ray properties, with 0.3-10 keV luminosities ~1038 erg s-1, and their X-ray lightcurves exhibit orbital periods ~30 h. Aims: We investigate similarities between IC 10 X-1 and NGC 300 X-1, as well as differences between these systems and the known Galactic BH binary systems. Methods: We have examined all four XMM-Newton observations of NGC 300 X-1, as well as the single XMM-Newton observation of IC 10 X-1. For each observation, we extracted lightcurves and spectra from the pn, MOS1 and MOS2 cameras; power density spectra were constructed from the lightcurves, and the X-ray emission spectra were modeled. Results: Each source exhibits power density spectra that are well described by a power law with index, γ, ~1. Such variability is characteristic of turbulence in wind accretion or disc-accreting X-ray binaries (XBs) in the high state. In this state, Galactic XBs with known BH primaries have soft, thermal emission; however the emission spectra of NGC 300 X-1 and IC 10 X-1 in the XMM-Newton observations are predominantly non-thermal. Furthermore, the Observation 1 spectrum of NGC 300 X-1 is strikingly similar to that of IC 10 X-1. Conclusions: The remarkable similarity between the behaviour of NGC 300 X-1 in Observation 1 and that of IC 10 X-1 lends strong evidence for NGC 300 X-1 being a BH+WR binary. Our spectral modeling rules out Bondi-Hoyle accretion onto a neutron star (NS) for NGC 300 X-1, but not a disc-accreting NS+WR system, nor a NS low mass X-ray binary (LMXB) that is merely coincident with the WR. We favour disc accretion for both systems, but cannot exclude Bondi-Hoyle accretion onto a BH. The unusual spectra of NGC 300 X-1 and IC 10 X-1 may be due to these systems existing in a persistently high state, whereas all known BH LMXBs

  3. The X-ray spectral and timing properties of a major radio flare episode in Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Koljonen, Karri I. I.; Hannikainen, Diana C.; McCollough, Michael L.; Pooley, Guy G.; Trushkin, Sergei A.; Droulans, Robert

    2013-02-01

    The microquasar Cygnus X-3 is known for massive outbursts that emit radiation from radio to γ-rays associated with jet ejection events. Using Principal Component Analysis to probe fast (~1 min) X-ray spectral evolution followed by subsequent spectral fits to the time-averaged spectra (~3 ks), we find that the overall X-ray variability during major outbursts can be attributed to two components. The spectral evolution of these components are best fitted with hybrid Comptonization and thermal bremsstrahlung components. Most of the X-ray variability is attributed to the hybrid Comptonization component. However, the spectral evolution of the thermal component is linked to a change in the X-ray spectral state. Phase-folding the fit results shows that the thermal component is restricted to two orbital phase regions opposite to each other, possibly indicating a flattened stellar wind from the Wolf-Rayet companion.

  4. X-1 in flight

    NASA Technical Reports Server (NTRS)

    1947-01-01

    The Bell Aircraft Corporation X-1-1 (#46-062) in flight. The shock wave pattern in the exhaust plume is visible. The X-1 series aircraft were air-launched from a modified Boeing B-29 or a B-50 Superfortress bombers. The X-1-1 was painted a bright orange by Bell Aircraft. It was thought that the aircraft would be more visable to those doing the tracking during a flight. When NACA received the airplanes they were painted white, which was an easier color to find in the skies over Muroc Air Field in California. This particular craft was nicknamed 'Glamorous Glennis' by Chuck Yeager in honor of his wife, and is now on permanent display in the Smithsonian Institution's National Air and Space Museum in Washington, DC. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all

  5. X-1 in flight

    NASA Technical Reports Server (NTRS)

    1947-01-01

    The Bell Aircraft Corporation X-1-1 (#46-062) in flight. The shock wave pattern in the exhaust plume is visible. The X-1 series aircraft were air-launched from a modified Boeing B-29 or a B-50 Superfortress bombers. The X-1-1 was painted a bright orange by Bell Aircraft. It was thought that the aircraft would be more visable to those doing the tracking during a flight. When NACA received the airplanes they were painted white, which was an easier color to find in the skies over Muroc Air Field in California. This particular craft was nicknamed 'Glamorous Glennis' by Chuck Yeager in honor of his wife, and is now on permanent display in the Smithsonian Institution's National Air and Space Museum in Washington, DC. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all

  6. X-1 on display

    NASA Technical Reports Server (NTRS)

    1949-01-01

    A Bell Aircraft Corporation X-1 series aircraft on display at an Open House at NACA Muroc Flight Test Unit or High-Speed Flight Research Station hangar on South Base of Edwards Air Force Base, California. (The precise date of the photo is uncertain, but it is probably before 1948.) The instrumentation that was carried aboard the aircraft to gather data is on display. The aircraft data was recorded on oscillograph film that was read, calibrated, and converted into meaningful parameters for the engineers to evaluate from each research flight. In the background of the photo are several early U.S. jets. These include several Lockheed P-80 Shooting Stars, which were used as chase planes on X-1 flights; two Bell P-59 Airacomets, the first U.S. jet pursuit aircraft (fighter in later parlance); and a prototype Republic XP-84 Thunderjet. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for eXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant

  7. X1 Exoskeleton

    NASA Image and Video Library

    NASA's Ironman-Like Exoskeleton Could Give Astronauts, Paraplegics Improved Mobility and Strength. While NASA's X1 robotic exoskeleton can't do what you see in the movies, the latest robotic, space...

  8. Prospects for High Energy Detection of Microquasars with the AGILE and GLAST Gamma-Ray Telescopes

    SciTech Connect

    Santolamazza, Patrizia; Pittori, Carlotta; Verrecchia, Francesco

    2007-08-21

    We estimate the sensitivities of the AGILE and GLAST {gamma}-ray experiments taking into account two cases for the galactic {gamma}-ray diffuse background (at high galactic latitude and toward the galactic center). Then we use sensitivities to estimate microquasar observability with the two experiments, assuming the {gamma}-ray emission above 100 MeV of a recent microquasar model.

  9. Cygnus Orbital ATK OA-6 Liftoff

    NASA Image and Video Library

    2016-03-22

    Cape Canaveral Air Force Station carrying an Orbital ATK Cygnus resupply spacecraft on a commercial resupply services mission to the International Space Station. Liftoff was at 11:05 p.m. EDT. Cygnus will deliver the second generation of a portable onboard printer to demonstrate 3-D printing, an instrument for first space-based observations of the chemical composition of meteors entering Earth’s atmosphere and an experiment to study how fires burn in microgravity.

  10. Cygnus Orbital ATK OA-6 Press Opportunity

    NASA Image and Video Library

    2016-03-08

    Inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, a Cygnus cargo spacecraft is being prepared for the upcoming Orbital ATK Commercial Resupply Services-6 mission to deliver hardware and supplies to the International Space Station. Technicians and engineers are clad in "bunny suits." The cleanroom garments are worn to prevent contamination in the controlled environment. The Cygnus is scheduled to lift off atop a United Launch Alliance Atlas V rocket on March 22.

  11. 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

  12. Gigantic Cosmic Corkscrew Reveals New Details About Mysterious Microquasar

    NASA Astrophysics Data System (ADS)

    2004-10-01

    Making an extra effort to image a faint, gigantic corkscrew traced by fast protons and electrons shot out from a mysterious microquasar paid off for a pair of astrophysicists who gained new insights into the beast's inner workings and also resolved a longstanding dispute over the object's distance. Microquasar SS 433 VLA Image of Microquasar SS 433 CREDIT: Blundell & Bowler, NRAO/AUI/NSF (Click on Image for Larger Version) The astrophysicists used the National Science Foundation's Very Large Array (VLA) radio telescope to capture the faintest details yet seen in the plasma jets emerging from the microquasar SS 433, an object once dubbed the "enigma of the century." As a result, they have changed scientists' understanding of the jets and settled the controversy over its distance "beyond all reasonable doubt," they said. SS 433 is a neutron star or black hole orbited by a "normal" companion star. The powerful gravity of the neutron star or black hole draws material from the stellar wind of its companion into an accretion disk of material tightly circling the dense central object prior to being pulled onto it. This disk propels jets of fast protons and electrons outward from its poles at about a quarter of the speed of light. The disk in SS 433 wobbles like a child's top, causing its jets to trace a corkscrew in the sky every 162 days. The new VLA study indicates that the speed of the ejected particles varies over time, contrary to the traditional model for SS 433. "We found that the actual speed varies between 24 percent to 28 percent of light speed, as opposed to staying constant," said Katherine Blundell, of the University of Oxford in the United Kingdom. "Amazingly, the jets going in both directions change their speeds simultaneously, producing identical speeds in both directions at any given time," Blundell added. Blundell worked with Michael Bowler, also of Oxford. The scientists' findings have been accepted by the Astrophysical Journal Letters. SS 433 New VLA

  13. The nature of NML Cygnus

    NASA Technical Reports Server (NTRS)

    Morris, M.; Jura, M.

    1983-01-01

    Since the discovery of NML Cyg by Neugebauer et al. (1965), its nature has been uncertain because its distance and luminosity are not known. NML Cyg is partially surrounded by an H II region which is heavily obscured by intervening interstellar matter. This H II region has been mapped in the continuum at 21 cm, and it seems clearly associated with the star. In the present investigation it is proposed that the H II region has been created by ionizing radiation from the Cyg OB2 association. The close agreement between the observed structure of the H II region and that predicted by the considered model provides strong evidence that NML Cyg is indeed at the distance of the association, 2 kpc. At this distance it is among the most luminous red stars shown. Because of its high luminosity, NML Cygnus is probably a massive star of perhaps 50 solar masses.

  14. The AGILE monitoring of Cygnus X-3: transient gamma-ray emission and spectral constraints

    NASA Astrophysics Data System (ADS)

    Piano, G.; Tavani, M.; Vittorini, V.; Trois, A.; Giuliani, A.; Bulgarelli, A.; Evangelista, Y.; Coppi, P.; Del Monte, E.; Sabatini, S.; Striani, E.; Donnarumma, I.; Hannikainen, D.; Koljonen, K. I. I.; McCollough, M.; Pooley, G.; Trushkin, S.; Zanin, R.; Barbiellini, G.; Cardillo, M.; Cattaneo, P. W.; Chen, A. W.; Colafrancesco, S.; Feroci, M.; Fuschino, F.; Giusti, M.; Longo, F.; Morselli, A.; Pellizzoni, A.; Pittori, C.; Pucella, G.; Rapisarda, M.; Rappoldi, A.; Soffitta, P.; Trifoglio, M.; Vercellone, S.; Verrecchia, F.

    2012-09-01

    We present the AGILE-GRID (Astro-rivelatore Gamma a Immagini LEggero - Gamma-Ray Imaging Detector) monitoring of Cygnus X-3, during the period between November 2007 and July 2009. We report here the whole AGILE-GRID monitoring of Cygnus X-3 in the AGILE "pointing" mode data-taking, to confirm that the γ-ray activity coincides with the same repetitive pattern of multiwavelength emission and analyze in depth the overall γ-ray spectrum by assuming both leptonic and hadronic scenarios. Seven intense γ-ray events were detected in this period, with a typical event lasting one or two days. These durations are longer than the likely cooling times of the γ-ray emitting particles, implying we see continuous acceleration rather than the result of an impulsive event such as the ejection of a single plasmoid that then cools as it propagates outwards. Cross-correlating the AGILE-GRID light curve with both X-ray and radio monitoring data, we find that the main events of γ-ray activity were detected while the system was in soft spectral X-ray states (RXTE/ASM (Rossi X-ray Timing Explorer/All-Sky Monitor)count rate in the 3-5 keV band ≳ 3 counts s-1), that coincide with local and often sharp minima of the hard X-ray flux (Swift/BAT (Burst Alert Telescope) count rate ≲0.02 counts cm-2 s-1), a few days before intense radio outbursts. This repetitive temporal coincidence between the γ-ray transient emission and spectral state changes of the source turns out to be the spectral signature of γ-ray activity from this microquasar. These γ-ray events may thus reflect a sharp transition in the structure of the accretion disk and its corona, which leads to a rebirth of the microquasar jet and subsequent enhanced activity in the radio band. The γ-ray differential spectrum of Cygnus X-3 (100 MeV-3 GeV), which was obtained by averaging the data collected by the AGILE-GRID during the γ-ray events, is consistent with a power law of photon index α = 2.0±0.2. Finally, we examine

  15. 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.

  16. 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.

  17. Modeling the X-ray light curves of Cygnus X-3. Possible role of the jet

    NASA Astrophysics Data System (ADS)

    Vilhu, O.; Hannikainen, D. C.

    2013-02-01

    Context. We address the physics behind the soft X-ray light curve asymmetries in Cygnus X-3, a well-known microquasar. Aims: Observable effects of the jet close to the line-of-sight were investigated and interpreted within the frame of light curve physics. Methods: The path of a hypothetical imprint of the jet, advected by the Wolf-Rayet-wind, was computed and its crossing with the line-of-sight during the binary orbit determined. We explored the possibility that physically this "imprint" is a formation of dense clumps triggered by jet bow shocks in the wind ("clumpy trail"). Models for X-ray continuum and emission line light curves were constructed using two absorbers: mass columns along the line-of-sight of i) the WR wind and ii) the clumpy trail, as seen from the compact star. These model light curves were compared with the observed ones from the RXTE/ASM (continuum) and Chandra/HETG (emission lines). Results: We show that the shapes of the Cyg X-3 light curves can be explained by the two absorbers using the inclination and true anomaly angles of the jet as derived from gamma-ray Fermi/LAT observations. The clumpy trail absorber is much larger for the lines than for the continuum. We suggest that the clumpy trail is a mixture of equilibrium and hot (shock heated) clumps. Conclusions: A possible way for studying jets in binary stars when the jet axis and the line-of-sight are close to each other is demonstrated. The X-ray continuum and emission line light curves of Cygnus X-3 can be explained by two absorbers: the WR companion wind plus an absorber lying in the jet path (clumpy trail). We propose that the clumpy trail absorber is due to dense clumps triggered by jet bow shocks.

  18. 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....

  19. Search for neutrino emission from microquasars with the ANTARES telescope

    NASA Astrophysics Data System (ADS)

    Galatà, S.

    2012-12-01

    Neutrino telescopes are nowadays exploring a new window of observation on the high energy universe and may shed light on the longstanding problem regarding the origin of cosmic rays. The ANTARES neutrino telescope is located underwater 40 km offshore from the Southern coast of France, on a plateau at 2475 m depth. Since 2007 it observes the high energy (>100 GeV) neutrino sky looking for cosmic neutrino sources. Among the candidate neutrino emitters are microquasars, i.e. galactic X-ray binaries exhibiting relativistic jets, which may accelerate hadrons thus producing neutrinos, under certain conditions. These sources are also variable in time and undergo X-ray or gamma ray outburst that can be related to the acceleration of relativistic particles witnessed by their radio emission. These events can provide a trigger to the neutrino search, with the advantage of drastically reducing the atmospheric neutrino background. A search for neutrino emission from microquasar during outbursts is presented based on the data collected by ANTARES between 2007 and 2010. Upper limits are shown and compared with the predictions.

  20. Discovery of a high-energy gamma-ray-emitting persistent microquasar

    PubMed

    Paredes; Marti; Ribo; Massi

    2000-06-30

    Microquasars are stellar x-ray binaries that behave as a scaled-down version of extragalactic quasars. The star LS 5039 is a new microquasar system with apparent persistent ejection of relativistic plasma at a 3-kiloparsec distance from the sun. It may also be associated with a gamma-ray source discovered by the Energetic Gamma Ray Experiment Telescope (EGRET) on board the COMPTON-Gamma Ray Observatory satellite. Before the discovery of LS 5039, merely a handful of microquasars had been identified in the Galaxy, and none of them was detected in high-energy gamma-rays.

  1. Contributions from the CYGNUS/Milagro Collaboration

    SciTech Connect

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

    1995-09-01

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

  2. The nucleus of the Cygnus A galaxy

    NASA Astrophysics Data System (ADS)

    Vestergaard, M.; Barthel, P. D.

    1993-02-01

    New obtained high resolution optical images of the prototypical luminous radio galaxy Cygnus A (3C 405) indicate an inhomogeneous distribution of obscuring dust and, in combination with previous data, three types of radiation (stellar and blue featureless continuum as well as luminous line emission) in its central regions. The alleged double nucleus finds its origin in heavy obscuration coupled to excess line emission in the central regions of an otherwise normal giant elliptical galaxy. A strongly reddened nuclear component, coincident with the Cygnus A radio core, is found to emit faint but concentrated narrow line emission. All data appear consistent with identification of Cygnus A as a radio-loud quasar having its radio axis oriented at about 35 deg from the sky plane. The presumed dust torus obscuring the quasar continuum is inferred to be smaller than 800 parsec.

  3. Coordinated Radio and High-Energy Observations of Cygnus X-3 with the Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Williams, Peter K. G.; Bower, G. C.; Tomsick, J. A.; Allen Telescope Array Team

    2011-01-01

    The microquasar Cygnus X-3 is one of the few Galactic sources known to produce relativistic jets and can be one of the brightest radio sources in the Galaxy when flaring. In late 2009 it became the first such system to be seen in the gamma-ray regime with detections by both AGILE and Fermi. We have observed Cyg X-3 at 3 GHz every 5 days for the past six months with the Allen Telescope Array in conjunction with space-based X-ray (INTEGRAL, RXTE) and gamma-ray (Fermi) observations. We present results from both the long-term dataset and intensive observing sessions in which we obtain the radio lightcurve of Cyg X-3 on 10-minute timescales. We focus particularly on a May 2010 minor flare event for which we have coverage in all three bands.The first phase of the ATA was funded through generous grants from the Paul G. Allen Family Foundation. UC Berkeley, the SETI Institute, the National Science Foundation (Grant No. 0540599), Sun Microsystems, Xilinx, Nathan Myhrvold, Greg Papadopoulos, and other corporations and individual donors contributed additional funding.

  4. Preparation for Bagging OA-7 CYGNUS

    NASA Image and Video Library

    2017-02-21

    In the Space Station Processing Facility high bay at NASA's Kennedy Space Center in Florida, technicians are preparing Orbital ATK's CYGNUS pressurized cargo module for bagging. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on March 19, 2017. CYGNUS will deliver thousands of pounds of supplies, equipment and scientific research materials to the space station.

  5. KAMAG Arrival for OA-7 CYGNUS

    NASA Image and Video Library

    2017-02-21

    In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, a KAMAG transporter has arrived in the high bay. Technicians are preparing Orbital ATK's CYGNUS pressurized cargo module for bagging. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on March 19, 2017. CYGNUS will deliver thousands of pounds of supplies, equipment and scientific research materials to the space station.

  6. The period derivative of Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Lamb, R. C.; Dower, R. G.; Fickle, R. K.

    1979-01-01

    X-rays from Cygnus X-3 have been observed during early 1978 with the detectors of the SAS 3 satellite. These observations, in conjunction with earlier Uhuru and ANS data, indicate that the 4.8 hr period of Cygnus X-3 is increasing at a rate of (5.1 + or - 1.3) times to the -6th per year. The sign and magnitude for this change are incompatible with a rotation model for the period and are in reasonable agreement with model predictions for orbital changes associated with mass loss and transfer in a binary system.

  7. Cygnus Orbital ATK OA-6 Liftoff

    NASA Image and Video Library

    2016-03-22

    A United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida carrying an Orbital ATK Cygnus resupply spacecraft on a commercial resupply services mission to the International Space Station. Liftoff was at 11:05 p.m. EDT. Cygnus will deliver the second generation of a portable onboard printer to demonstrate 3-D printing, an instrument for first space-based observations of the chemical composition of meteors entering Earth’s atmosphere and an experiment to study how fires burn in microgravity.

  8. Cygnus Orbital ATK OA-6 Liftoff

    NASA Image and Video Library

    2016-03-22

    A United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying an Orbital ATK Cygnus resupply spacecraft on a commercial resupply services mission to the International Space Station. Liftoff was at 11:05 p.m. EDT. Cygnus will deliver the second generation of a portable onboard printer to demonstrate 3-D printing, an instrument for first space-based observations of the chemical composition of meteors entering Earth’s atmosphere and an experiment to study how fires burn in microgravity.

  9. Cygnus Orbital ATK OA-6 Liftoff

    NASA Image and Video Library

    2016-03-22

    In a time-lapse exposure, a United Launch Alliance Atlas V rocket lifts off from Space Launch Complex 41 at Cape Canaveral Air Force Station carrying an Orbital ATK Cygnus resupply spacecraft on a commercial resupply services mission to the International Space Station. Liftoff was at 11:05 p.m. EDT. Cygnus will deliver the second generation of a portable onboard printer to demonstrate 3-D printing, an instrument for first space-based observations of the chemical composition of meteors entering Earth’s atmosphere and an experiment to study how fires burn in microgravity.

  10. Cygnus Orbital ATK OA-6 Press Opportunity

    NASA Image and Video Library

    2016-03-08

    Inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, members of the news media get a close-up view of a Cygnus cargo vessel. The spacecraft is scheduled for the upcoming Orbital ATK Commercial Resupply Services-6 mission to deliver hardware and supplies to the International Space Station. Reporters, technicians and engineers are clad in "bunny suits." The cleanroom garments are worn to prevent contamination in the controlled environment. The Cygnus is scheduled to lift off atop a United Launch Alliance Atlas V rocket on March 22.

  11. Deep X-ray Observations of an Ongoing Merger and 400 Myr of AGN Activity in Cygnus A

    NASA Astrophysics Data System (ADS)

    Wise, Michael W.; De Vries, Martijn; Nulsen, Paul; Snios, Bradford; Birkinshaw, Mark; Worrall, Diana; Duffy, Ryan; Halbesma, Timo; Donnert, Julius; Hardcastle, Martin

    2017-08-01

    We present a detailed spatial and spectral analysis of the large-scale X-ray emission associated with the merging cluster of galaxies containing the powerful Cygnus A radio galaxy. Using a new 1 Msec exposure from the ongoing Chandra XVP project, we have mapped the large-scale structure, temperature and abundance of the ICM in a 1 Mpc x 1 Mpc region surrounding Cygnus A. This new, deep exposure resolves unprecedented detail in the jets, lobes, and cocoon shock associated with Cygnus A, and provides new insights into the emission mechanisms that produce these features as well as implications for the ongoing activity of the central AGN. On larger scales, these new data reveal complex and dramatic temperature, pressure, entropy and metallicity structure in the ICM surrounding Cygnus A. We confirm the presence of large-scale X-ray emission associated with the two merging cluster components seen previously in lower resolution data. The temperature structure on the scale of the merger exhibits an asymmetric enhancement to the NW consistent with projected hotter gas from the merger shock. Using the derived density and temperature profiles in the two merging sub-cluster components as inputs, we have constructed a grid of hydro-dynamical simulations to constrain the geometry of the merger system. These models imply a pre-merger system with a 1:1 mass ratio at the virial radius with an inclination toward the line of sight of 35-45 deg. In addition to the merger-induced temperature asymmetry, we find evidence for additional surface brightness and temperature features indicative of previous outburst activity in Cygnus A over the past 400 Myr. Based on the location and strength of these features, we derive the energy associated with these previous outbursts and place constraints on the growth of the black hole in Cygnus A over that timescale.

  12. Hercules X-1: Pulsed gamma-rays detected above 150 GeV

    NASA Technical Reports Server (NTRS)

    Cawley, M. F.; Fegan, D. J.; Gibbs, K. G.; Gorham, P. W.; Kenny, S.; Lamb, R. C.; Liebing, D. F.; Porter, N. A.; Stenger, V. J.; Weekes, T. C.

    1985-01-01

    The 1.24 second binary pulsar Her X-1, first observed in X-rays in 1971 by UHURU has now been seen as a sporadic gamma ray source from 1 TeV up to at least 500 TeV. In addition, reprocessed optical and infrared pulses are seen from the companion star HZ Herculis. Thus measurements of the Her X-1/HZ Herculis system span 15 decades in energy, rivaling both the Crab pulsar and Cygnus X-3 in this respect for a discrete galactic source.

  13. Positron annihilation signatures associated with the outburst of the microquasar V404 Cygni

    NASA Astrophysics Data System (ADS)

    Siegert, Thomas; Diehl, Roland; Greiner, Jochen; Krause, Martin G. H.; Beloborodov, Andrei M.; Bel, Marion Cadolle; Guglielmetti, Fabrizia; Rodriguez, Jerome; Strong, Andrew W.; Zhang, Xiaoling

    2016-03-01

    Microquasars are stellar-mass black holes accreting matter from a companion star and ejecting plasma jets at almost the speed of light. They are analogues of quasars that contain supermassive black holes of 106 to 1010 solar masses. Accretion in microquasars varies on much shorter timescales than in quasars and occasionally produces exceptionally bright X-ray flares. How the flares are produced is unclear, as is the mechanism for launching the relativistic jets and their composition. An emission line near 511 kiloelectronvolts has long been sought in the emission spectrum of microquasars as evidence for the expected electron-positron plasma. Transient high-energy spectral features have been reported in two objects, but their positron interpretation remains contentious. Here we report observations of γ-ray emission from the microquasar V404 Cygni during a recent period of strong flaring activity. The emission spectrum around 511 kiloelectronvolts shows clear signatures of variable positron annihilation, which implies a high rate of positron production. This supports the earlier conjecture that microquasars may be the main sources of the electron-positron plasma responsible for the bright diffuse emission of annihilation γ-rays in the bulge region of our Galaxy. Additionally, microquasars could be the origin of the observed megaelectronvolt continuum excess in the inner Galaxy.

  14. Positron annihilation signatures associated with the outburst of the microquasar V404 Cygni.

    PubMed

    Siegert, Thomas; Diehl, Roland; Greiner, Jochen; Krause, Martin G H; Beloborodov, Andrei M; Bel, Marion Cadolle; Guglielmetti, Fabrizia; Rodriguez, Jerome; Strong, Andrew W; Zhang, Xiaoling

    2016-03-17

    Microquasars are stellar-mass black holes accreting matter from a companion star and ejecting plasma jets at almost the speed of light. They are analogues of quasars that contain supermassive black holes of 10(6) to 10(10) solar masses. Accretion in microquasars varies on much shorter timescales than in quasars and occasionally produces exceptionally bright X-ray flares. How the flares are produced is unclear, as is the mechanism for launching the relativistic jets and their composition. An emission line near 511 kiloelectronvolts has long been sought in the emission spectrum of microquasars as evidence for the expected electron-positron plasma. Transient high-energy spectral features have been reported in two objects, but their positron interpretation remains contentious. Here we report observations of γ-ray emission from the microquasar V404 Cygni during a recent period of strong flaring activity. The emission spectrum around 511 kiloelectronvolts shows clear signatures of variable positron annihilation, which implies a high rate of positron production. This supports the earlier conjecture that microquasars may be the main sources of the electron-positron plasma responsible for the bright diffuse emission of annihilation γ-rays in the bulge region of our Galaxy. Additionally, microquasars could be the origin of the observed megaelectronvolt continuum excess in the inner Galaxy.

  15. The interaction of microquasar jets with the companion wind

    NASA Astrophysics Data System (ADS)

    Heinz, Sebastian; Yoon, Doosoo; Zdziarski, Andrzei

    2017-08-01

    The interaction of relativistic jets with their environment is one of the best ways to measure their properties. This was worked extremely well in the case of AGN, where studies of X-ray cavities have have opened entirely new ways to reliably measure jet powers for entire ensembles of AGN. In the case of microquasar jets interacting with the ISM, this method is hampered by the large angular scales and low surface brightness of the observable signatures, as well as the temporary nature of the obsrvabes. However, before the jet ever reaches the ISM, it must travel through the wind from the companion star. This interaction is fundamentally different from the way AGN jets interact with their surroundings. I will discuss analytic and numerical work that investigates the unique aspects of jet-wind interaction and show how it can provide a robust and powerful diagnostic tool, complementary to other methods of constraining jet physics.

  16. Star Formation and Young Clusters in Cygnus

    NASA Astrophysics Data System (ADS)

    Reipurth, B.; Schneider, N.

    2008-12-01

    The Great Cygnus Rift harbors numerous very active regions of current or recent star formation. In this part of the sky we look down a spiral arm, s= o regions from only a few hundred pc to several kpc are superposed. The North America and Pelican nebulae, parts of a single giant HII region, are the best known of the Cygnus regions of star formation and are located at a distance of only about 600 pc. Adjacent, but at a distance of about 1.7 kpc, is the Cygnus X region, a ˜10° complex of actively star forming molecular clouds and young clusters. The most massive of these clusters is the 3-4 Myr old Cyg OB2 association, containing several thousand OB stars and akin to the young globular clusters in the LMC. The rich populations of young low and high mass stars and protostars associated with the massive cloud complexes in Cygnus are largely unexplored and deserve systematic study.

  17. 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.

  18. Optical Observations and Modeling of a Possible Black Hole HMXB and Cygnus X-1 Progenitor

    NASA Astrophysics Data System (ADS)

    Gomez, Sebastian; Grindlay, Jonathan E.

    2017-01-01

    HD96670 is a single line spectroscopic binary in the Carina OB2 association. The source shows variable HeII emission in the GOSSS survey of O-star spectra (Sota et al. 2014). We did follow up high resolution spectroscopic observations with the 1.5m SMARTS telescope and CHIRON spectrograph, and improved the mass function of the system to f(m) = 0.1026 M_sun. We also carried out photometric observations with the AAVSO astronet telescope network and the 1.3m SMARTS telescope and determined an orbital period of P = 5.2838 days. This means that for an O8.5V primary, the minimum secondary mass is > 3.4 M_sun, therefore ruling out a white dwarf or neutron star secondary. The most likely companion is either a B star, or a black hole. We also modeled the light curve using the PHOEBE light curve synthesis software in order to constrain the parameters of the system.

  19. XMM-Newton, RXTE, and Radio Observations of CYGNUS X-1

    NASA Technical Reports Server (NTRS)

    Miller, Jon; Mushotzky, Richard (Technical Monitor)

    2005-01-01

    XMM-Newton observations of this target were not made successfully until October 2004, due to problems of high background and instrumental flaring in the prior observability windows. Processed data for analysis was delivered a few months after the observations. Thus, work on these observations is beginning now, in the spring of 2005. A preliminary analysis of these observations reveals a complex spectrum, with relativistic emission line features. Detailed modeling and interpretation of this data will be completed over several months.

  20. X-ray Variability Constraints on Compton Cloud Models of Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Vaughan, Brian

    1999-01-01

    We have now completed this work, and all related publications have either appeared in print or are currently in press. A list of these publications is given below. There have been essentially three works that have arisen from this proposal. Spectral analysis of the data is presented in Dove et al. (1998a). Timing analysis is presented in Nowak et al. (1999a). Theoretical implications of the data analysis are discussed in Nowak et al. (1999b). Preliminary versions of all these works were presented at various conferences, and are reported in Nowak et al. (1997, 1998), Wilms et al. (1997), and Dove et al. (1998b). The grant was predominantly used for salary support for Dr. Michael Nowak, Dr. James Dove, and Dr. J. Wilms during the course of these projects. Grant funds were also used for Dr. Nowak to travel to Caltech to perform data analysis with Dr. Brian Vaughan, and for Dr. Wilms to visit JILA, University of Colorado, where much of this work was performed.

  1. XMM-Newton, RXTE, and Radio Observations of CYGNUS X-1

    NASA Technical Reports Server (NTRS)

    Miller, Jon; Mushotzky, Richard (Technical Monitor)

    2005-01-01

    XMM-Newton observations of this target were not made successfully until October 2004, due to problems of high background and instrumental flaring in the prior observability windows. Processed data for analysis was delivered a few months after the observations. Thus, work on these observations is beginning now, in the spring of 2005. A preliminary analysis of these observations reveals a complex spectrum, with relativistic emission line features. Detailed modeling and interpretation of this data will be completed over several months.

  2. Gamma rays from clumpy wind-jet interactions in high-mass microquasars

    NASA Astrophysics Data System (ADS)

    de la Cita, V. M.; del Palacio, S.; Bosch-Ramon, V.; Paredes-Fortuny, X.; Romero, G. E.; Khangulyan, D.

    2017-07-01

    Context. The stellar winds of the massive stars in high-mass microquasars are thought to be inhomogeneous. The interaction of these inhomogeneities, or clumps, with the jets of these objects may be a major factor in gamma-ray production. Aims: Our goal is to characterize a typical scenario of clump-jet interaction, and calculate the contribution of these interactions to the gamma-ray emission from these systems. Methods: We use axisymmetric, relativistic hydrodynamical simulations to model the emitting flow in a typical clump-jet interaction. Using the simulation results we perform a numerical calculation of the high-energy emission from one of these interactions. The radiative calculations are performed for relativistic electrons locally accelerated at the jet shock, and the synchrotron and inverse Compton radiation spectra are computed for different stages of the shocked clump evolution. We also explore different parameter values, such as viewing angle and magnetic field strength. The results derived from one clump-jet interaction are generalized phenomenologically to multiple interactions under different wind models, estimating the clump-jet interaction rates, and the resulting luminosities in the GeV range. Results: If particles are efficiently accelerated in clump-jet interactions, the apparent gamma-ray luminosity through inverse Compton scattering with the stellar photons can be significant even for rather strong magnetic fields and thus efficient synchrotron cooling. Moreover, despite the standing nature or slow motion of the jet shocks for most of the interaction stage, Doppler boosting in the postshock flow is relevant even for mildly relativistic jets. Conclusions: For clump-to-average wind density contrasts greater than or equal to ten, clump-jet interactions could be bright enough to match the observed GeV luminosity in Cyg X-1 and Cyg X-3 when a jet is present in these sources, with required non-thermal-to-total available power fractions greater than

  3. X-1 cockpit instrument panel

    NASA Technical Reports Server (NTRS)

    1949-01-01

    A Bell Aircraft Corporation X-1 series aircraft cockpit instruments display. The gages reflecting the airplane's parameters such as indicated pressure altitude, indicated airspeed, rocket chamber pressure, fuel and liquid oxygen supply, angle of attack, angle of sideslip, and Mach number are shown. Other information pertinent for the pilot to complete a successful flight is also displayed. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on Jan. 25, 1946. Powered flights began in December 1946. On Oct. 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the

  4. X-1E on Lakebed

    NASA Technical Reports Server (NTRS)

    1955-01-01

    The Bell Aircraft Corporation X-1E is shown here in 1955 on the Rogers Dry Lakebed at Edwards Air Force Base in California. The X-1E was actually the extensively rebuilt X-1-2 (46-063). It had a new thin wing, a stepped canopy, and a low-pressure fuel system. It flew through 1958, bringing the X-1 saga to a close after twelve years of research flying at the NACA High-Speed Flight Station. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to

  5. First detection of Allobilharzia visceralis (Schistosomatidae, Trematoda) from Cygnus cygnus in Japan.

    PubMed

    Hayashi, Kei; Ichikawa-Seki, Madoka; Ohari, Yuma; Mohanta, Uday Kumar; Aita, Junya; Satoh, Hiroshi; Ehara, Shiori; Tokashiki, Minami; Shiroma, Tomoko; Azuta, Ayumi; Oka, Nozomi; Watanabe, Takuya; Harasawa, Ryo; Inohana, Satoshi; Ichijo, Toshihiro; Furuhama, Kazuhisa

    2017-02-01

    Adult schistosomes were detected in the veins or capillaries of the large intestine, mesentery, liver, and adrenal glands in eight of 13 whooper swans (Cygnus cygnus) examined in Iwate Prefecture, Japan. However, neither eggs nor severe tissue injuries were observed in any of the swans. The schistosomes were definitively identified as Allobilharzia visceralis based on the nucleotide sequences of the ribosomal internal transcribed spacer (ITS) region. Allobilharzia visceralis infections have been reported in whooper swan in Iceland and tundra swan (Cygnus columbianus) in North America. These detections suggest that A. visceralis is distributed extensively along the swan flyways because the swans are migratory birds. To the best of our knowledge, this is the first report of A. visceralis infection in Asia. Copyright © 2016. Published by Elsevier Ireland Ltd.

  6. The Cocoon Shock of Cygnus A

    NASA Astrophysics Data System (ADS)

    Snios, Bradford; Kraft, Ralph P.; Nulsen, Paul; Wise, Michael W.

    2017-08-01

    Cygnus A is an archetype FRII radio galaxy and is the nearest powerful radio galaxy in the Universe. It is hosted by the central galaxy of a rich cluster, and X-ray observations of the system provide a unique opportunity to investigate the physical structure of a powerful radio galaxy as well as the galaxy's impact on the cluster host. My talk will cover our analysis of the recent deep exposure Chandra observations of Cygnus A's cocoon shock. The observational data is fitted with multiple models to assess the speed and strength of the cocoon shock to high accuracy. The results show that the shocked gas is driven with a generally uniform pressure, although a pressure difference of 30% is seen between the radio lobes. I will discuss implications of these findings on both the radio jet properties and the jet's interactions with its cluster atmosphere.

  7. Documenting Cygnus Capture by Canadarm2

    NASA Image and Video Library

    2013-09-29

    ISS037-E-003918 (29 Sept. 2013) --- At the windows in the International Space Station?s Cupola, European Space Agency astronaut Luca Parmitano, Expedition 37 flight engineer, uses a laser range finder during rendezvous, capture and docking operations with the first Cygnus commercial cargo spacecraft (out of frame) built by Orbital Sciences Corp. The two spacecraft converged at 7:01 a.m. EDT on Sept. 29, 2013.

  8. Documenting Cygnus Capture by Canadarm2

    NASA Image and Video Library

    2013-09-29

    ISS037-E-003937 (29 Sept. 2013) --- At the windows in the International Space Station?s Cupola, European Space Agency astronaut Luca Parmitano, Expedition 37 flight engineer, uses a laser range finder during rendezvous, capture and docking operations with the first Cygnus commercial cargo spacecraft built by Orbital Sciences Corp. The two spacecraft converged at 7:01 a.m. EDT on Sept. 29, 2013.

  9. A Possible Merging Companion to Cygnus A

    NASA Astrophysics Data System (ADS)

    Canalizo, G.; Max, C. E.; Whysong, D.; Antonucci, R.; Dahm, S. E.; Lacy, M.

    2003-05-01

    Different lines of evidence indicate that the powerful FR II radio galaxy Cygnus A harbors a heavily extincted quasar. However, until now, no direct evidence has been found indicating that the nuclear activity may have been triggered by a strong interaction or merger. We recently obtained Keck adaptive optics imaging and spectroscopic observations of the core of Cygnus A of unprecedented resolution and depth. These images show a secondary point source 400 pc away from the radio nucleus. The colors and near infrared spectra of this object rule out the possibility that it may be a foreground star. We discuss the possibility that the object may instead be the dense, gas stripped core of a low luminosity merging galaxy that has thus far survived the merger with the giant elliptical host to Cygnus A. This work was performed under the auspices of the U.S. Department of Energy, National Nuclear Security Administration by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48

  10. Relativistic Jets in Active Galactic Nuclei and Microquasars

    NASA Astrophysics Data System (ADS)

    Romero, Gustavo E.; Boettcher, M.; Markoff, S.; Tavecchio, F.

    2017-07-01

    Collimated outflows (jets) appear to be a ubiquitous phenomenon associated with the accretion of material onto a compact object. Despite this ubiquity, many fundamental physics aspects of jets are still poorly understood and constrained. These include the mechanism of launching and accelerating jets, the connection between these processes and the nature of the accretion flow, and the role of magnetic fields; the physics responsible for the collimation of jets over tens of thousands to even millions of gravitational radii of the central accreting object; the matter content of jets; the location of the region(s) accelerating particles to TeV (possibly even PeV and EeV) energies (as evidenced by γ-ray emission observed from many jet sources) and the physical processes responsible for this particle acceleration; the radiative processes giving rise to the observed multi-wavelength emission; and the topology of magnetic fields and their role in the jet collimation and particle acceleration processes. This chapter reviews the main knowns and unknowns in our current understanding of relativistic jets, in the context of the main model ingredients for Galactic and extragalactic jet sources. It discusses aspects specific to active Galactic nuclei (especially blazars) and microquasars, and then presents a comparative discussion of similarities and differences between them.

  11. Relativistic Jets in Active Galactic Nuclei and Microquasars

    NASA Astrophysics Data System (ADS)

    Romero, Gustavo E.; Boettcher, M.; Markoff, S.; Tavecchio, F.

    2017-01-01

    Collimated outflows (jets) appear to be a ubiquitous phenomenon associated with the accretion of material onto a compact object. Despite this ubiquity, many fundamental physics aspects of jets are still poorly understood and constrained. These include the mechanism of launching and accelerating jets, the connection between these processes and the nature of the accretion flow, and the role of magnetic fields; the physics responsible for the collimation of jets over tens of thousands to even millions of gravitational radii of the central accreting object; the matter content of jets; the location of the region(s) accelerating particles to TeV (possibly even PeV and EeV) energies (as evidenced by γ-ray emission observed from many jet sources) and the physical processes responsible for this particle acceleration; the radiative processes giving rise to the observed multi-wavelength emission; and the topology of magnetic fields and their role in the jet collimation and particle acceleration processes. This chapter reviews the main knowns and unknowns in our current understanding of relativistic jets, in the context of the main model ingredients for Galactic and extragalactic jet sources. It discusses aspects specific to active Galactic nuclei (especially blazars) and microquasars, and then presents a comparative discussion of similarities and differences between them.

  12. Jet Formation and Dynamics: Comparison of Quasars and Microquasars

    NASA Astrophysics Data System (ADS)

    Kundt, Wolfgang

    Quasars and Microquasars share the following properties: (i) They have similar, elongated morphologies - reminiscent of being driven by supersonic beams - consisting of cores, knots, and heads, with jet-opening angles <~ 10^-2, and no beam branching; (ii) core/lobe power ratios of 10^2 +/- 2; (iii) fluctuating, broad and hard core spectra; (iv) (occasional) sidedness; (v) (occasional) superluminal growth. In all cases, the central engine is thought to be a rotating magnet whose reconnecting magnetic fields generate the relativistic pair plasma - of typical Lorentz factor 10^3 +/- 2 - which rams the jet channels and blows the cocoons (subsonically) after having been stalled in a head. The supersonic jets form on passing a central deLaval nozzle, first proposed by Blandford and Rees in 1974, which forms naturally due to the huge density contrast of 10^-8.3T_4 with respect to the ambient medium (of temperature T, T_4:=T/10^4 K). Beam stability and narrowness are likewise guaranteed by the density contrast (of jet fluid and CSM). Observed are both the (thermal) radiation of the rammed channel-wall material, and the synchrotron radiation of the deflected beam particles.

  13. Three-Dimensional Numerical Hydrodynamical Simulation of Low/hard and High/soft States in Accretion Discs of Microquasars and Quasars on Base of Undefined Precession

    NASA Astrophysics Data System (ADS)

    Nazarenko, V. V.; Nazarenko, S. V.

    In this study, the models of slaved precession of accretion disc and donors radiation-driven wind were performed using three-dimensional numerical astrophysical methods by the example of microquasar Cyg X-1. As is shown, in the course of precession of the accretion disc blown by the donor's wind the states with high and low temperature (low and high mass accretion rate, respectively) start being generated in the centre of disc. Our computations of disc precession performed on base of undefined precession that means each point of rotation axis of accretion disc makes unclosed difficult curve instead of a circle as it is in case of definite precession. In this case, the transition between states of high and low temperature takes place irregularly and not depend on precession period. The duration of transition between these both states is less than intervals of states on several orders of magnitudes.

  14. Variable very-high-energy gamma-ray emission from the microquasar LS I +61 303.

    PubMed

    Albert, J; Aliu, E; Anderhub, H; Antoranz, P; Armada, A; Asensio, M; Baixeras, C; Barrio, J A; Bartelt, M; Bartko, H; Bastieri, D; Bavikadi, S R; Bednarek, W; Berger, K; Bigongiari, C; Biland, A; Bisesi, E; Bock, R K; Bordas, P; Bosch-Ramon, V; Bretz, T; Britvitch, I; Camara, M; Carmona, E; Chilingarian, A; Ciprini, S; Coarasa, J A; Commichau, S; Contreras, J L; Cortina, J; Curtef, V; Danielyan, V; Dazzi, F; De Angelis, A; de Los Reyes, R; De Lotto, B; Domingo-Santamaría, E; Dorner, D; Doro, M; Errando, M; Fagiolini, M; Ferenc, D; Fernández, E; Firpo, R; Flix, J; Fonseca, M V; Font, L; Fuchs, M; Galante, N; Garczarczyk, M; Gaug, M; Giller, M; Goebel, F; Hakobyan, D; Hayashida, M; Hengstebeck, T; Höhne, D; Hose, J; Hsu, C C; Isar, P G; Jacon, P; Kalekin, O; Kosyra, R; Kranich, D; Laatiaoui, M; Laille, A; Lenisa, T; Liebing, P; Lindfors, E; Lombardi, S; Longo, F; López, J; López, M; Lorenz, E; Lucarelli, F; Majumdar, P; Maneva, G; Mannheim, K; Mansutti, O; Mariotti, M; Martínez, M; Mase, K; Mazin, D; Merck, C; Meucci, M; Meyer, M; Miranda, J M; Mirzoyan, R; Mizobuchi, S; Moralejo, A; Nilsson, K; Oña-Wilhelmi, E; Orduña, R; Otte, N; Oya, I; Paneque, D; Paoletti, R; Paredes, J M; Pasanen, M; Pascoli, D; Pauss, F; Pavel, N; Pegna, R; Persic, M; Peruzzo, L; Piccioli, A; Poller, M; Pooley, G; Prandini, E; Raymers, A; Rhode, W; Ribó, M; Rico, J; Riegel, B; Rissi, M; Robert, A; Romero, G E; Rügamer, S; Saggion, A; Sánchez, A; Sartori, P; Scalzotto, V; Scapin, V; Schmitt, R; Schweizer, T; Shayduk, M; Shinozaki, K; Shore, S N; Sidro, N; Sillanpää, A; Sobczynska, D; Stamerra, A; Stark, L S; Takalo, L; Temnikov, P; Tescaro, D; Teshima, M; Tonello, N; Torres, A; Torres, D F; Turini, N; Vankov, H; Vitale, V; Wagner, R M; Wibig, T; Wittek, W; Zanin, R; Zapatero, J

    2006-06-23

    Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and can be used to elucidate the physics of relativistic jets. We report the detection of variable gamma-ray emission above 100 gigaelectron volts from the microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar orbital phase, which suggests that the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or absorption processes.

  15. 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.

  16. 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.; hide

    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.

  17. The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and γ-rays

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV γ-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and γ-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ~3 day softening and recovery of the X-ray emission, followed almost immediately by a ~1 Jy radio flare at 15 GHz, followed by a 4.3σ γ-ray flare (E > 100 MeV) ~1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the γ-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 γ-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 γ-ray emission from Cyg X-3.

  18. 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.

  19. Theoretical overview on high-energy emission in microquasars

    NASA Astrophysics Data System (ADS)

    Bosch-Ramon, Valentí

    2007-06-01

    Microquasar (MQ) jets are sites of particle acceleration and synchrotron emission. Such synchrotron radiation has been detected coming from jet regions of different spatial scales, which for the instruments at work nowadays appear as compact radio cores, slightly resolvedradio jets, or (very) extended structures (e.g. Mirabel and Rodríguez, 1999; Fender, 2001; Corbel et al., 2002). Because of the presence of relativistic particles and dense photon, magnetic and matter fields, these outflows are also the best candidates to generate the very high-energy (VHE) gamma-rays detected coming from two of these objects, LS 5039 and LS I +61 303 (Aharonian, 2005; Aharonian et al., 2006a; and Albert, 2006, respectively), and may be contributing significantly to the X-rays emitted from the MQ core (e.g. Markoff et al., 2001; Bosch-Ramon et al., 2005a). In addition, beside electromagnetic radiation, jets at different scales are producing some amount of leptonic and hadronic cosmic rays (CR), and evidences of neutrino production in these objects may be eventually found. In this work, we review on the different physical processes that may be at work in or related to MQ jets. The jet regions capable to produce significant amounts of emission at different wavelengths have been reduced to the jet base, the jet at scales of the order of the size of the system orbital semi-major axis, the jet middle scales (the resolved radio jets), and the jet termination point. The surroundings of the jet could be sites of multiwavelength emission as well, deserving also an insight. We focus on those scenarios, either hadronic or leptonic, in which it seems more plausible to generate both photons from radio to VHE and high-energy neutrinos. We briefly comment as well on the relevance of MQ as possible contributors to the galactic CR in the GeV-PeV range.

  20. X-1E on Lakebed

    NASA Technical Reports Server (NTRS)

    1955-01-01

    The Bell Aircraft Corporation X-1E in 1955 on the Rogers Dry Lakebed near the NACA High-Speed Flight Station, Edwards, California. The X-1E was notable for being shorter, with a thinner wing than the X-1A, -B, and -D. Aerodynamic heating caused the ailerons, rudder, and elevators to remain unpainted throughout the X-1E's flight test program. When the ventral fins were added, they were left unpainted too. On August 31, 1956, the aircraft reached a top speed of 1,480 miles per hour (Mach 2.24). There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14

  1. X-1A on lakebed

    NASA Technical Reports Server (NTRS)

    1955-01-01

    The Bell Aircraft Corporation X-1A (48-1384) is photographed in July 1955 sitting on Rogers Dry Lake at Edwards Air Force Base, California. This view of the left side of the aircraft shows the change to the X-1A canopy from the X-1s (see photo E49-0039 under XS-1) The nose boom carries an angle-of-attack and angle-of-sideslip vane, along with a pitot tube for measuring static and impact pressures. The fuselage length is 35 feet 8 inches, with a wing span of 28 feet. The X-1A was created to explore stability and control characteristics at speeds in excess of Mach 2 and altitudes greater than 90,000 feet. Bell test pilot Jean 'Skip' Ziegler made six test flights in the X-1A between 14 February and 25 April 1953. Air Force test pilots Maj. Charles 'Chuck' Yeager and Maj. Arthur 'Kit' Murray made 18 flights between 21 November 1953 and 26 August 1954. NACA test pilot Joseph Walker made one successful flight on 20 July 1955. During a second flight attempt, on 8 August 1955, an explosion damaged the X-1A shortly before launch. Walker, unhurt, climbed up into the JTB-29A mothership, and the X-1A was jettisoned over the Edwards AFB bombing range.

  2. 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.

  3. Interaction of Cygnus A with its environment

    NASA Astrophysics Data System (ADS)

    Nulsen, Paul E. J.; Young, Andrew J.; Kraft, Ralph P.; McNamara, Brian R.; Wise, Michael W.

    2015-03-01

    Cygnus A, the nearest truly powerful radio galaxy, resides at the centre of a massive galaxy cluster. Chandra X-ray observations reveal its cocoon shocks, radio lobe cavities and an X-ray jet, which are discussed here. It is argued that X-ray emission from the outer regions of the cocoon shocks is nonthermal. The X-ray jets are best interpreted as synchrotron emission, suggesting that they, rather than the radio jets, are the path of energy flow from the nucleus to the hotspots. In that case, a model shows that the jet flow is non-relativistic and carries in excess of one solar mass per year.

  4. Cygnus Orbital ATK OA-6 Liftoff

    NASA Image and Video Library

    2016-03-22

    At Cape Canaveral Air Force Station's Space Launch Complex 41, a United Launch Alliance Atlas V rocket with a single-engine Centaur upper stage stands ready to boost an Orbital ATK Cygnus spacecraft on a resupply mission to the International Space Station. Science payloads include the second generation of a portable onboard printer to demonstrate three-dimensional printing, an instrument for first space-based observations of the chemical composition of meteors entering Earth’s atmosphere and an experiment to study how fires burn in microgravity.

  5. Cygnus Orbital ATK OA-6 Rollout

    NASA Image and Video Library

    2016-03-21

    At Cape Canaveral Air Force Station's Space Launch Complex 41, a United Launch Alliance Atlas V rocket with a single-engine Centaur upper stage stands ready to boost an Orbital ATK Cygnus spacecraft on a resupply mission to the International Space Station. Science payloads include the second generation of a portable onboard printer to demonstrate three-dimensional printing, an instrument for first space-based observations of the chemical composition of meteors entering Earth’s atmosphere and an experiment to study how fires burn in microgravity.

  6. Audible Noise Design of ISS Cargo Module "Cygnus"

    NASA Astrophysics Data System (ADS)

    Destefanis, Stefano; Paron, Alberto; Bandini, Flavio

    2014-06-01

    Orbital developed the Cygnus advanced manoeuvring spacecraft to demonstrate cargo delivery services under a NASA Commercial Orbital Transportation Services (COTS) Space Act Agreement.In addition to the COTS development and demonstration program, Orbital will utilize Cygnus to perform ISS resupply flights under the Commercial Resupply Service (CRS) contract.Starting in January 2014 Orbital launched its first of eight missions to deliver approximately 20,000 kilograms of cargo to the ISS (International Space Station). Cygnus will carry crew supplies, spares and scientific experiments to the ISS.Cygnus consists of a common service module and a pressurized cargo module. The pressurized cargo module is based on the Multi-Purpose Logistics Module (MPLM), developed by Thales Alenia Space for NASA. Since Cygnus pressurized cargo module will host astronauts performing daily tasks, it is required to be compliant with NASA guidelines related to acoustic comfort (working areas noise not to exceed NC-50 requirement) and safety (caution and warning alarms audibility).The main source of noise inside Cygnus is the ventilation fan, which happens to be the same model already installed on the ATV (Automated Transfer Vehicle) cargo module: however, the strategy adopted to limit its acoustic disturbance had to be differently tailored.This paper presents the activities (assumptions, design, characterization, testing) that led to define the type of noise control devices used on Cygnus, up to its first successful flight (module labelled "PCM0") to the ISS, where it reached 2nd place in the "quietest visiting modules" ranking.

  7. X-1A impact site

    NASA Technical Reports Server (NTRS)

    1955-01-01

    A photo taken on 8 August 1955, showing the remains of the Bell X-1A The Bell X-1A (Serial # 48-1384) was designed for aerodynamic stability and air load research. It was delivered to Edwards Air Force Base on 7 January 1953. The aircraft made its first glide flight on 14 February with Bell test pilot Jean 'Skip' Ziegler at the controls. Ziegler also flew the first powered flight in the X-1A on 21 February. Contractor flights in the aircraft continued through April, at which time the X-1A was temporarily grounded for modifications. Flight operations were resumed on 21 November 1953 with Maj. Charles 'Chuck' Yeager at the controls. During a flight on 12 December, Yeager took the X-1A to a record-breaking speed of Mach 2.44 at an altitude of 75,000 feet. He then encountered the unpleasant phenomemon of inertia coupling. The X-1A tumbled out of control, knocking Yeager unconscious briefly before entering an inverted spin. Fortunately Yeager regained his senses and control of the aircraft 60 miles from Edwards at an altitude of 25,000 feet. Shaken, but unharmed, he brought the rocket plane in for a safe landing on Rogers Dry Lake. Next, the X-1A was used for a series of high-altitude missions piloted by Maj. Arthur 'Kit' Murray. Fourteen flights proved necessary to meet the program requirements, with only four being successful. During the test series, Murray set several unofficial world altitude records. The highest (90,440 feet) was set on 26 August 1954. Following completion of the altitude program, the aircraft was turned over to the National Advisory Committee for Aeronautics (NACA). The X-1A underwent more modifications and was returned to flight status in July 1955. The first NACA-sponsored flight, piloted by Joseph A. Walker, took place on 20 July. The second NACA mission was to be the 25th flight of the X-1A. The flight began normally on 8 August 1955, with the X-1A shackled to the underside of a JTB-29A (45-21800) piloted by Stanley Butchart and John 'Jack' Mc

  8. X-1 aircraft in flight

    NASA Technical Reports Server (NTRS)

    1949-01-01

    The first of the rocket-powered research aircraft, the X-1 (originally designated the XS-1), was a bullet-shaped airplane that was built by the Bell Aircraft Company for the US Air Force and the National Advisory Committee for Aeronautics (NACA). The mission of the X-1 was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier'. The first of the three X-1s was glide-tested at Pinecastle Field, FL, in early 1946. The first powered flight of the X-1 was made on Dec. 9, 1946, at Muroc Army Air Field (later redesignated Edwards Air Force Base) with Chalmers Goodlin, a Bell test pilot,at the controls. On Oct. 14, 1947, with USAF Captain Charles 'Chuck' Yeager as pilot, the aircraft flew faster than the speed of sound for the first time. Captain Yeager ignited the four-chambered XLR-11 rocket engines after being air-launched from under the bomb bay of a B-29 at 21,000 ft. The 6,000-lb thrust ethyl alcohol/liquid oxygen burning rockets, built by Reaction Motors, Inc., pushed him up to a speed of 700 mph in level flight. Captain Yeager was also the pilot when the X-1 reached its maximum speed of 957 mph. Another USAF pilot. Lt. Col. Frank Everest, Jr., was credited with taking the X-1 to its maximum altitude of 71,902 ft. Eighteen pilots in all flew the X-1s. The number three plane was destroyed in a fire before evermaking any powered flights. A single-place monoplane, the X-1 was 31 ft long, 10 ft high, and had a wingspan of 29 ft. It weighed 4,900 lb and carried 8,200 lb of fuel. It had a flush cockpit with a side entrance and no ejection seat. The following movie runs about 20 seconds, and shows several air-to-air views of X-1 Number 2 and its modified B-50 mothership. It begins with different angles of the X-1 in-flight while mated to the B-50's bomb bay, and ends showing the air-launch. The X-1 drops below the B-50, then accelerates away as the rockets ignite.

  9. 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}.

  10. Hard X-ray component in the Sco X-1 spectrum: Synchrotron emission from a nono-quasar

    NASA Astrophysics Data System (ADS)

    Manchanda, R. K.

    Sco X-1 is a low mass X-ray binary system and is the very first X-ray source to be discovered in 1962. From the recent observation of a resolved radio jet the souce has been included in the list of galactic microquasars. The observed spectral data in the 2-20 keV energy band fits a Free-free emission from a hot plasma. Above 20 keV, a hard tail has been reported on occasions. During our continuuing balloon borne X-ray survey in the 20-200 keV region using high sensitivity Large Area Scintillation counter Experiment, Sco X-1 was observed on two different occasions. Eventhough the total X-ray luminosity of the source different, the spectral nature of the source did not show any variation. The presence of hard X-ray flux is unmistakable. We present the spectra data in the hard X-ray band and discuss the results in terms of geometrical characteristics of the X-ray source and the observed temporal variations. It is proposed that while a core activity is similar to the micro-quasars, the absence of abrupt changes similar to GRS 1915+105, in the CGRO and RXTE data suggest a with much reduced magnitude.

  11. Modelling a Simultaneous Radio/X-Ray Flare from Cyg X-1

    NASA Technical Reports Server (NTRS)

    Leventis, Konstantinos; Markoff, Sera; Wilsm, Joern; Nowak, Michael A.; Maitra, Dipankar; Pottschmidt, Katja; Pooley, Guy G.; Kreykenbohm, Ingo; Rotschild, Richard E.

    2008-01-01

    The long-term monitoring campaign of Cyg X-1 has provided the detection of the first simultaneous radio/X-ray flare seen from that source. We investigate the physical characteristics of the event in terms of emission from a homogeneous, expanding blob of pair-plasma, superimposed on a baseline flux in both bands. We find that while the radio flare can be reconstructed under various configurations of a cooling blob, continuous (re)acceleration of particles inside the jet is necessary to sustain X-ray emission at the levels implied by the data, for the observed duration. We present major results of the modelling and discuss implications for the role of microquasar jets.

  12. INTERPRETATION OF THE 115 DAY PERIODIC MODULATION IN THE X-RAY FLUX OF NGC 5408 X-1

    SciTech Connect

    Foster, D. L.; Charles, P. A.; Holley-Bockelmann, K.

    2010-12-20

    We comment on the recent observation of a 115 day modulation in the X-ray flux of the ultraluminous X-ray source (ULX) NGC 5408 X-1, and in particular, the interpretation of this modulation as the orbital period. We suggest that this modulation may instead be due to a precessing jet, and is thus superorbital in nature. Comparing the properties of this ULX with those of the prototypical micro-quasar SS 433, we argue that NGC 5408 X-1 is very similar to SS 433: a hyper-accreting stellar-mass black hole in a shorter-period binary. If the analogy holds, the 115 day modulation is best explained by the still poorly understood physics of inner-disk/jet precession and a longer observing baseline would be able to reveal an intrinsic phase jitter that is associated with such a precession.

  13. 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.

  14. Low state hard x-ray observation of Cyg X-1

    NASA Astrophysics Data System (ADS)

    Bazzano, A.; La Padula, C.; Manchanda, R. K.; Polcaro, V. F.; Ubertini, P.; Staubert, R.; Kendziorra, E.

    1991-08-01

    We report a ``super-low'' state observation of the black hole candidate Cygnus X-1 in the energy range 15-120 keV. The data were obtained with the ``POKER'' experiment, designed to perform high sensitivity observations of cosmic sources in the hard X-Ray range (15-120 keV). The telescope consisted of an array of three high pressure Xenon Multiwire Proportional Counters (MWPC) with a total sensitive area of 7,500 cm2. The detectors were filled at a pressure of 2.6 bar with a mixture of Xe/Argon/Isobutane to provide an efficiency greater than 20% for photon energies from 15 keV to 110 keV. The MWPC spectral resolution was 13% at 60 keV. The fields of view of the three MWPCs were coaligned and limited by means of hexagonal copper collimators with an aperture of 5.0 degree FWHM. In order to provide imaging capability to the telescope one of the MWPC was equipped with two co-rotating Rotation Modulation Collimators, developed at AIT, and modulating a geometrical area of 1,600 cm2 of the detector. The telescope was launched from the Milo Base, Sicily (Italy), on 1985 August 5, and scanning and pointed observations were carried out on the Crab Nebula, A0535+26, MCG 8-11-11, NGC 4151, Cygnus X-1 and Her X-1. The Cygnus X-1 and Crab photon spectra are well described by single power laws, with photon indeces of α=1.87 and α=2.17 and intensities of 2.57×10-3 and 2.32×10-3 ph cm-2 s-1 keV-1 at 50 keV, respectively. The low hard X-ray emission from Cyg X-1 confirms that during the POKER observation the source was in a ``low'' state as also supported by EXOSAT data collected at lower energies on August 12.

  15. 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.

  16. Heartworm in a mute swan (Cygnus olor).

    PubMed

    de Bruijn, N D; Velkers, F C; Gröne, A

    2009-11-01

    A severely emaciated female adult mute swan (Cygnus olor) was euthanized after a period of intensive supportive care in a wild bird rehabilitation centre. Necropsy revealed severe myocardial haemorrhages in the right ventricular free wall associated with the presence of adult heartworm (Sarconema eurycerca). On histological examination, multifocal randomly scattered blood-filled cavities without endothelial or epithelial lining (migration tracts) and surrounded by necrotic debris mixed with fibrinoid deposits and a mixed inflammatory infiltrate were seen, as well as mild multifocal degeneration and necrosis of adjacent myocardial fibres. In some of the lesions, cut sections of adult female filarial nematodes revealed numerous microfilariae in their uteri. This report is the first published case of Sarconema eurycerca in a mute swan in The Netherlands.

  17. Contribution due to clumpy winds to the non-thermal emission in microquasar jets

    NASA Astrophysics Data System (ADS)

    de la Cita, V. M.; del Palacio, S.; Bosch-Ramon, V.; Paredes-Fortuny, X.; Romero, G. E.; Khangulyan, D.

    2017-03-01

    Powerful jets in high-mass microquasars are likely to be crossed by dense inhomogeneities (clumps) from the stellar winds, which may lead to particle acceleration and thus nonthermal emission in X-rays and gamma-rays. We characterise a typical clump-jet interaction scenario and compute the contribution to the high-energy emission of these systems. We use hydrodynamical simulations of a single clump-jet interaction and we use this result to compute its non-thermal (synchrotron and inverse Compton) radiation. We present several radiative calculations for a number of clump states, as the clump is disrupted over time, letting different parameters vary (viewing angle, magnetic field). We obtain significant amounts of non-thermal radiation from jet-clump interactions in high-mass microquasars.

  18. Are 3C 120 and Other Active Galactic Nuclei Overweight Microquasars?

    NASA Astrophysics Data System (ADS)

    Marscher, Alan P.

    2005-11-01

    The appearance of superluminal radio knots follows drops in the X-ray flux in the FR1 radio galaxy 3C 120 and possibly the FR2 source 3C 111. This corresponds in a very general way to the behavior of the X-ray binary GRS 1915 + 105, but the light curves of the microquasar are much richer in detail. Starting in 2003.7, the character of the radio and X-ray light curves of 3C 120 changed, perhaps signaling a new stage of activity. I discuss here what one might expect when a microquasar is scaled up to AGN dimensions, and compare this with what we see in 3C 120. There is a mismatch between expectations and observations.

  19. On the Content of Cold Electrons in Blazar and Microquasar Jets

    NASA Astrophysics Data System (ADS)

    Zheleznyakov, V. V.; Koryagin, S. A.

    2005-11-01

    We explore the possibility of determining the corpuscular composition of the plasma in the relativistic jets of blazars and microquasars from data on the polarization and intensity of their radio synchrotron emission. We have constructed a universal diagram that allows the relative content of nonrelativistic electrons to be established in specific objects using information about their frequency spectra and polarization at individual frequencies. As a result, we have found that the electron plasma component in the jets of the blazars 3C 279 and BL Lac is relativistic. In the jets of the microquasar GRS 1915+105, the cold plasma density may be comparable to or considerably higher than the relativistic particle density.

  20. Dynamical and radiative simulations of γ-ray jets in microquasars

    NASA Astrophysics Data System (ADS)

    Smponias, T.; Kosmas, T. S.

    2014-02-01

    The emission of γ-rays in jets emanating from the vicinity of collapsed stellar remnants, in binary systems known as microquasars, is investigated using a three-dimensional relativistic hydrocode (PLUTO), in combination with two in-house radiative transfer codes. Even though a great number of stellar systems may be addressed by such models, we restrict ourselves to the concrete example of the SS433 X-ray binary, the only microquasar with a definite hadronic content in its jets, as verified from spectral line observations. A variety of system configurations have been examined, by employing a hadron-based emission mechanism. The dependence of the γ-ray emissions on certain dynamical source properties, such as the hydrodynamic parameters of the mass-flow density, the gas-pressure and the temperature of the ejected matter, is simulated. Radiative properties, especially the assumed high-energy proton population inside the jet plasma, and its effect on the calculated emission, are also examined. Two sets of initial conditions of the chosen microquasar are employed, in order to cover different scenarios pertaining to the system under consideration.

  1. Evolution of relativistic jets from XTE J1550-564 and the environment of microquasars

    NASA Astrophysics Data System (ADS)

    Zhang, Shuang Nan; Hao, Jing Fang

    2008-10-01

    Two relativistic X-ray jets have been detected with the Chandra X-ray observatory in the black hole X-ray transient XTE J1550-564. We report a full analysis of the evolution of the two jets with a gamma-ray burst external shock model. A plausible scenario suggests a cavity outside the central source and the jets first travelled with constant velocity and then are slowed down by the interactions between the jets and the interstellar medium (ISM). The best fitted radius of the cavity is ~0.36 pc on the eastern side and ~0.46 pc on the western side, and the densities also show asymmetry, of ~0.015 cm-3 on the east to ~0.21 cm-3 on the west. Large scale low density region is also found in another microquasar system, H 1743-322. These results are consistent with previous suggestions that the environment of microquasars should be rather vacuous, compared to the normal Galactic environment. A generic scenario for microquasar jets is proposed, classifying the observed jets into three main categories, with different jet morphologies (and sizes) corresponding to different scales of vacuous environments surrounding them.

  2. JET TRAILS AND MACH CONES: THE INTERACTION OF MICROQUASARS WITH THE INTERSTELLAR MEDIUM

    SciTech Connect

    Yoon, D.; Morsony, B.; Heinz, S.; Wiersema, K.; Fender, R. P.; Russell, D. M.; Sunyaev, R.

    2011-11-20

    A subset of microquasars exhibits high peculiar velocity with respect to the local standard of rest due to the kicks they receive when being born in supernovae. The interaction between the radio plasma released by microquasar jets from such high-velocity binaries with the interstellar medium must lead to the production of trails and bow shocks similar to what is observed in narrow-angle tailed radio galaxies and pulsar wind nebulae. We present a set of numerical simulations of this interaction that illuminate the long-term dynamical evolution and the observational properties of these microquasar bow-shock nebulae and trails. We find that this interaction always produces a structure that consists of a bow shock, a trailing neck, and an expanding bubble. Using our simulations to model emission, we predict that the shock surrounding the bubble and the neck should be visible in H{sub {alpha}} emission, the interior of the bubble should be visible in synchrotron radio emission, and only the bow shock is likely to be detectable in X-ray emission. We construct an analytic model for the evolution of the neck and bubble shape and compare this model with observations of the X-ray binary SAX J1712.6-3739.

  3. Accretion disk winds as the jet suppression mechanism in the microquasar GRS 1915+105.

    PubMed

    Neilsen, Joseph; Lee, Julia C

    2009-03-26

    Stellar-mass black holes with relativistic jets, also known as microquasars, mimic the behaviour of quasars and active galactic nuclei. Because timescales around stellar-mass black holes are orders of magnitude smaller than those around more distant supermassive black holes, microquasars are ideal nearby 'laboratories' for studying the evolution of accretion disks and jet formation in black-hole systems. Whereas studies of black holes have revealed a complex array of accretion activity, the mechanisms that trigger and suppress jet formation remain a mystery. Here we report the presence of a broad emission line in the faint, hard states and narrow absorption lines in the bright, soft states of the microquasar GRS 1915+105. ('Hard' and 'soft' denote the character of the emitted X-rays.) Because the hard states exhibit prominent radio jets, we argue that the broad emission line arises when the jet illuminates the inner accretion disk. The jet is weak or absent during the soft states, and we show that the absorption lines originate when the powerful radiation field around the black hole drives a hot wind off the accretion disk. Our analysis shows that this wind carries enough mass away from the disk to halt the flow of matter into the radio jet.

  4. A Search for Very High Energy Gamma-Ray Emission from Scorpius X-1 with the Magic Telescopes

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Alvarez, E. A.; Antonelli, L. A.; Antoranz, P.; Asensio, M.; Backes, M.; Barrio, J. A.; Bastieri, D.; Becerra González, J.; Bednarek, W.; Berdyugin, A.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnoli, G.; Bordas, P.; Borla Tridon, D.; Bosch-Ramon, V.; Braun, I.; Bretz, T.; Cañellas, A.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Cossio, L.; Covino, S.; Dazzi, F.; De Angelis, A.; De Cea del Pozo, E.; De Lotto, B.; Delgado Mendez, C.; Diago Ortega, A.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Elsaesser, D.; Ferenc, D.; Fonseca, M. V.; Font, L.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido, D.; Giavitto, G.; Godinović, N.; Hadasch, D.; Häfner, D.; Herrero, A.; Hildebrand, D.; Höhne-Mönch, D.; Hose, J.; Hrupec, D.; Huber, B.; Jogler, T.; Klepser, S.; Krähenbühl, T.; Krause, J.; La Barbera, A.; Lelas, D.; Leonardo, E.; Lindfors, E.; Lombardi, S.; López, M.; Lorenz, E.; Makariev, M.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Miyamoto, H.; Moldón, J.; Moralejo, A.; Munar-Adrover, P.; Nieto, D.; Nilsson, K.; Orito, R.; Oya, I.; Paneque, D.; Paoletti, R.; Pardo, S.; Paredes, J. M.; Partini, S.; Pasanen, M.; Pauss, F.; Perez-Torres, M. A.; Persic, M.; Peruzzo, L.; Pilia, M.; Pochon, J.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reichardt, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rügamer, S.; Saggion, A.; Saito, K.; Saito, T. Y.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shayduk, M.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Sobczynska, D.; Spanier, F.; Spiro, S.; Stamerra, A.; Steinke, B.; Storz, J.; Strah, N.; Surić, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thom, M.; Tibolla, O.; Torres, D. F.; Treves, A.; Vankov, H.; Vogler, P.; Wagner, R. M.; Weitzel, Q.; Zabalza, V.; Zandanel, F.; Zanin, R.

    2011-07-01

    The acceleration of particles up to GeV or higher energies in microquasars has been the subject of considerable theoretical and observational efforts in the past few years. Sco X-1 is a microquasar from which evidence of highly energetic particles in the jet has been found when it is in the so-called Horizontal Branch (HB), a state when the radio and hard X-ray fluxes are higher and a powerful relativistic jet is present. Here we present the first very high energy gamma-ray observations of Sco X-1, obtained with the MAGIC telescopes. An analysis of the whole data set does not yield a significant signal, with 95% CL flux upper limits above 300 GeV at the level of 2.4 × 10-12 cm-2 s-1. Simultaneous RXTE observations were conducted to provide the X-ray state of the source. A selection of the gamma-ray data obtained during the HB based on the X-ray colors did not yield a signal either, with an upper limit of 3.4 × 10-12 cm-2 s-1. These upper limits place a constraint on the maximum TeV luminosity to non-thermal X-ray luminosity of L VHE/L ntX <~ 0.02 that can be related to a maximum TeV luminosity to jet power ratio of L VHE/L j <~ 10-3. Our upper limits indicate that the underlying high-energy emission physics in Sco X-1 must be inherently different from that of the hitherto detected gamma-ray binaries.

  5. 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.

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

    USGS Publications Warehouse

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

    2014-01-01

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

  7. Pathogenesis of venous hypertrophy associated with schistosomiasis in whooper swans (Cygnus cygnus) in Japan.

    PubMed

    Akagami, Masataka; Nakamura, Kikuyasu; Nishino, Hiroto; Seki, Satoko; Shimizu, Hiromi; Yamamoto, Yu

    2010-03-01

    Thirteen whooper swans (Cygnus cygnus) affected with schistosomiasis were examined pathologically. Venous hypertrophy, characterized by marked nodular proliferation of medial smooth muscle fibers with frequent obliteration of the vascular lumen, was observed in eight of the 13 whooper swans. Venous hypertrophy was located in the medium-sized veins of the mesentery, the serosa, and the muscular layer of the duodenum, jejunum, ileum, and cecum. In addition, vascular lesions were seen in the capsule and parenchymal interstitia of the liver, spleen, kidney, heart, aorta, air sac, and pleura. In mild lesions, segmental proliferation of medial smooth muscles was observed in the venous medium of the mesentery and serosa. Moderate lesions had a proliferation of smooth muscles in the veins with obliteration of venous lumens. In marked lesions, more severe proliferation of veins extended into the intestinal muscular layers and depressed them. Schistosome parasites were found in the venous lumens of each of the eight whooper swans with vascular lesions. Bile pigments and hemosiderin were observed in the livers of whooper swans. In addition, adult nematodes (Sarconema sp.) were localized in the myocardium of four of the eight whooper swans. The venous hypertrophy may be caused by the proliferation of medial smooth muscle fibers induced by schistosomiasis.

  8. Optical kinematics in the Cygnus Loop. II - Interpretation

    NASA Astrophysics Data System (ADS)

    Greidanus, H.; Strom, R. G.

    1992-04-01

    Imaging Fabry-Perot observations in the lines of H alpha and O III were made of selected regions in the Cygnus Loop supernova remnant and a summary of the observations is given. Observations of the small-scale radial velocity structure of optical filaments are discussed and consideration is given to interpretation of the gas kinematics. The cloud model and radiative-sheet model are reviewed and it is concluded that the optical kinematics of the Cygnus Loop bear a greater resemblance to the radiative-sheet model. It is suggested that a narrow O III component is associated with the remnant and may be due to photoionized gas in the precursor region. This component allows the estimation of the systemic velocity of the Cygnus Loop and the derivation of a kinematic distance.

  9. VERITAS Observations of the Cygnus Region of the Galaxy

    NASA Astrophysics Data System (ADS)

    Bird, Ralph; VERITAS Collaboration

    2016-03-01

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

  10. Constraints on cosmic-ray observation of Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Barnhill, M. V., III; Gaisser, T. K.; Stanev, T.; Halzen, F.

    1985-01-01

    Two experimental groups working at different minimum energies have reported underground muons coming from the direction of Cygnus X-3 with rates that vary in synchrony with its binary period. At the Mont Blanc detector the events are, within statistics, uniformly spread over a 5 degree circle around the position of Cygnus X-3, even though the angular resolution is significantly better than this. The ratio of events in the phase peak to total muons observed rises as a function of minimum muon energy. An experiment also sees an excess in the number of pairs of codirectional multiple muon events arriving within about 5000 seconds of each other, the excess events coming from a direction about 20 degrees away from Cygnus X-3.

  11. Cygnus OA-4 Spacecraft on Approach to ISS

    NASA Image and Video Library

    2015-12-09

    ISS045e176110 (12/09/2015) --- Using the International Space Station’s robotic arm, Canadarm2 (right) NASA Flight Engineer Kjell Lindgren prepares to capture Orbital ATK’s Cygnus cargo vehicle Dec. 09, 2015. The space station crew and the robotics officer in mission control in Houston will position Cygnus for installation to the orbiting laboratory’s Earth-facing port of the Unity module. Among the more than 7,000 pounds of supplies aboard Cygnus are numerous science and research investigations and technology demonstrations, including a new life science facility that will support studies on cell cultures, bacteria and other microorganisms; a microsatellite deployer and the first microsatellite that will be deployed from the space station; several other educational and technology demonstration CubeSats; and experiments that will study the behavior of gases and liquids, clarify the thermo-physical properties of molten steel, and evaluate flame-resistant textiles.

  12. Observing campaign on 5 variables in Cygnus

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2015-10-01

    Dr. George Wallerstein (University of Washington) has requested AAVSO assistance in monitoring 5 variable stars in Cygnus now through December 2015. He is working to complete the radial velocity curves for these stars, and needs optical light curves for correlation with the spectra he will be obtaining. Wallerstein writes: "I need to know the time of max or min so I can assign a phase to each spectrum. Most classical Cepheids are quite regular so once a time of max or min can be established I can derive the phase of each observation even if my obs are several cycles away from the established max or min. MZ Cyg is a type II Cepheid and they are less regular than their type I cousins." SZ Cyg, X Cyg, VX Cyg, and TX Cyg are all classical Cepheids. V and visual observations are requested. These are long-period Cepheids, so nightly observations are sufficient. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (https://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details.

  13. The first simultaneous X-ray/gamma-ray observations of Cyg X-1 by Ginga and OSSE

    NASA Technical Reports Server (NTRS)

    Gierlinski, Marek; Zdziarski, A.; Johnson, W. Neil; Philips, Bernard F.; Ebisawa, Ken; Done, Chris

    1996-01-01

    The results of four simultaneous observations of Cygnus X-1 by Ginga and the orientated scintillation spectrometer experiment (OSSE) are presented. The X-ray/gamma ray spectra can be described by an intrinsic continuum and a component due to Compton reflection including an iron K alpha line. The intrinsic spectrum at X-ray energies is a power law with a photon spectral index of Gamma = 1.6. The intrinsic gamma ray spectrum can be phenomenologically described by either a power law without cutoff up to 150 keV and an exponential cutoff above this energy, or by an expoential cutoff power law and a second hard component.

  14. 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.

  15. OA-7 CYGNUS Processing Activities: Nano-Rack Installation

    NASA Image and Video Library

    2017-02-27

    Inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, technicians install several Nanoracks on the exterior of the Orbital ATK Cygnus pressurized cargo module. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station no earlier than March 21, 2017. Cygnus will deliver 7,600 pounds of supplies, equipment and scientific research materials to the space station.

  16. The Youngest Known X-Ray Binary: Circinus X-1 and Its Natal Supernova Remnant

    NASA Astrophysics Data System (ADS)

    Heinz, S.; Sell, P.; Fender, R. P.; Jonker, P. G.; Brandt, W. N.; Calvelo-Santos, D. E.; Tzioumis, A. K.; Nowak, M. A.; Schulz, N. S.; Wijnands, R.; van der Klis, M.

    2013-12-01

    Because supernova remnants are short-lived, studies of neutron star X-ray binaries within supernova remnants probe the earliest stages in the life of accreting neutron stars. However, such objects are exceedingly rare: none were known to exist in our Galaxy. We report the discovery of the natal supernova remnant of the accreting neutron star Circinus X-1, which places an upper limit of t < 4600 yr on its age, making it the youngest known X-ray binary and a unique tool to study accretion, neutron star evolution, and core-collapse supernovae. This discovery is based on a deep 2009 Chandra X-ray observation and new radio observations of Circinus X-1. Circinus X-1 produces type I X-ray bursts on the surface of the neutron star, indicating that the magnetic field of the neutron star is small. Thus, the young age implies either that neutron stars can be born with low magnetic fields or that they can rapidly become de-magnetized by accretion. Circinus X-1 is a microquasar, creating relativistic jets that were thought to power the arcminute-scale radio nebula surrounding the source. Instead, this nebula can now be attributed to non-thermal synchrotron emission from the forward shock of the supernova remnant. The young age is consistent with the observed rapid orbital evolution and the highly eccentric orbit of the system and offers the chance to test the physics of post-supernova orbital evolution in X-ray binaries in detail for the first time.

  17. The youngest known X-ray binary: Circinus X-1 and its natal supernova remnant

    SciTech Connect

    Heinz, S.; Sell, P.; Fender, R. P.; Jonker, P. G.; Brandt, W. N.; Calvelo-Santos, D. E.; Tzioumis, A. K.; Nowak, M. A.; Schulz, N. S.; Wijnands, R.; Van der Klis, M.

    2013-12-20

    Because supernova remnants are short-lived, studies of neutron star X-ray binaries within supernova remnants probe the earliest stages in the life of accreting neutron stars. However, such objects are exceedingly rare: none were known to exist in our Galaxy. We report the discovery of the natal supernova remnant of the accreting neutron star Circinus X-1, which places an upper limit of t < 4600 yr on its age, making it the youngest known X-ray binary and a unique tool to study accretion, neutron star evolution, and core-collapse supernovae. This discovery is based on a deep 2009 Chandra X-ray observation and new radio observations of Circinus X-1. Circinus X-1 produces type I X-ray bursts on the surface of the neutron star, indicating that the magnetic field of the neutron star is small. Thus, the young age implies either that neutron stars can be born with low magnetic fields or that they can rapidly become de-magnetized by accretion. Circinus X-1 is a microquasar, creating relativistic jets that were thought to power the arcminute-scale radio nebula surrounding the source. Instead, this nebula can now be attributed to non-thermal synchrotron emission from the forward shock of the supernova remnant. The young age is consistent with the observed rapid orbital evolution and the highly eccentric orbit of the system and offers the chance to test the physics of post-supernova orbital evolution in X-ray binaries in detail for the first time.

  18. 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.

  19. Performance of the Cygnus X-ray Source

    NASA Astrophysics Data System (ADS)

    Smith, John R.; Carlson, Randolph; Fulton, Robert D.; Altes, R.; Carboni, V.; Chavez, Jacob R.; Corcoran, P.; Coulter, William L.; Douglas, J.; Droemer, D.; Gibson, William A.; Helvin, Thomas B.; Henderson, David J.; Johnson, David L.; Maenchen, John E.; Mitton, Charlas V.; Molina, Isidro; Nishimoto, H.; Ormond, Eugene C.; Ortega, Paul A.; Quicksilver, Robert J.; Ridlon, Rae N.; Rose, Evan A.; Scholfield, David W.; Smith, I.; Valerio, Antonio R.; White, R.

    2002-12-01

    Cygnus is a radiographic x-ray source developed for support of the Sub-Critical Experiments Program at the Nevada Test Site. Major requirements for this application are: a dramatically reduced spot size as compared to both Government Laboratory and existing commercial alternatives, layout flexibility, and reliability. Cygnus incorporates proven pulsed power technology (Marx Generator, Pulse Forming Line, Water Transmission Line, and Inductive Voltage Adder sub-components) to drive a high voltage vacuum diode. In the case of Cygnus, a relatively new approach (the rod pinch diode [1]) is employed to achieve a small source diameter. Design specifications are: 2.25 MeV endpoint energy, < 1 mm source diameter, and >3 rads dose at 1 meter. The pulsed power and system architecture design plan has been previously presented [2]. The first set of Cygnus shots were geared to verification of electrical parameters and, therefore, used a large area diode configuration offering increased shot rate as compared to that of the rod pinch diode. In this paper we present results of initial rod pinch operation in terms of electrical and radiation parameters.

  20. 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.

  1. 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.

  2. New members of the massive stellar population in Cygnus

    NASA Astrophysics Data System (ADS)

    Comerón, F.; Pasquali, A.

    2012-07-01

    Context. The Cygnus OB2 association and its surroundings display the richest collection of massive stars in our nearby Galactic environment and a wealth of signposts of the interaction between these stars and the interstellar gas. Aims: We perform a magnitude-limited, homogeneous census of O and early B-type stars with accurate spectral classifications in the blue, in a 6° × 4° region centered on Cygnus OB2 that includes most of the Cygnus X complex, a sizeable fraction of the adjacent Cygnus OB9 association, and a large area of the field surrounding these complexes. Methods: By using reddening-free indices based on BJHK magnitudes from the USNO-B and 2MASS catalogs, we are able to produce a highly complete, highly uncontaminated sample of O and early B stars, which nearly duplicates any previous census of the region for the same range of spectral types. We provide the spectral types of 60 new O and B stars, as well as a list of an additional 60 candidates pending spectroscopic confirmation. In addition, the UBV imaging of the surroundings of three apparently isolated O stars is used to investigate the possible presence of small clusters of young stars around them. Results: Early-type stars are consistent with similar distances for Cygnus OB2, OB9, and the field stars surrounding them. We confirm previous findings of an older population in Cygnus OB2 spatially offset from where the stellar density of the association peaks. Some new remarkable objects are identified, including BD+40 4210, a B0 supergiant member of Cygnus OB2 that is among the brightest members of the association sharing some characteristics with luminous blue variable (LBV) candidates, located at a projected distance of 5 pc from another LBV candidate. A new O5If member of Cygnus OB9 is found, as well as several other O stars and B supergiants. On the other hand, while no obvious clustering is found around the apparently isolated O stars, the fields around two of them seem to contain objects with

  3. 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.

  4. Continuum and line emission in Cygnus A

    NASA Astrophysics Data System (ADS)

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

    1994-08-01

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

  5. X-1A in flight over lakebed

    NASA Technical Reports Server (NTRS)

    1953-01-01

    The Bell Aircraft Corporation X-1A (48-1384) returning from an Air Force test flight over Edwards Air Force Base, California in late 1953. A North American F-86A Sabre as chase plane will follow the X-1A to touchdown. The Rogers Dry Lake is the whitish area under the planes with the airfield at the edge of the dry lake. Bell test pilot Jean 'Skip' Ziegler made six flights between 14 February and 25 April 1953. Air Force test pilots Maj. Charles 'Chuck' Yeager and Maj. Arthur 'Kit' Murray made 18 test flights between 21 November 1953 and 26 August 1954. NACA test pilot Joseph Walker made one successful flight on 20 July 1955. During a second flight attempt, on 8 August 1955, an explosion damaged the aircraft shortly before launch. Walker, unhurt, climbed up into the JTB-29A mothership, and the X-1A was jettisoned over the Edwards AFB bombing range. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system

  6. Ejection of the Corona at State Transitions: a Common Behavior in Microquasars?

    NASA Astrophysics Data System (ADS)

    Prat, L.; Rodriguez, J.

    2009-05-01

    The onset of most microquasar outbursts is characterized by a state transition between a Low/Hard State (LHS) and a High/Soft State (HSS). Besides drastic spectral and timing changes, this transition often shows a discrete ejection event detectable in the radio range. However, the exact nature of the ejected material and the mechanisms that give birth to these phenomena are yet to be unraveled. Recent simultaneous radio and X-ray observations on several sources point to a coronal nature of the ejected material. In the cases of GRS 1915+105, XTE J1550-564, and the 2002 outburst of GX 339-4, the flux of the Compton component decreases sharply just before an ejection is detected in the radio range. Finally, in the case of H1743-322, drastic physical changes occurred in the corona just before the state transition, compatible with the disappearance of part of this medium. Thus, the behavior of at least 4 microquasars points in the direction of an ejection of the corona at the state transition, feature that is yet to be confirmed (or infirmed) in the case of other available sources.

  7. X-1E with Pilot Joe Walker

    NASA Technical Reports Server (NTRS)

    1958-01-01

    A photo of the X-1E with pilot Joe Walker suited up at the NASA High-Speed Flight Station, Edwards, California. The dice and 'Little Joe' are prominently displayed under the cockpit area. (Little Joe is a dice players slang term for two deuces.) Five years later when Walker reached 354,200 feet in the X-15, that aircraft carried similar artwork - 'Little Joe the II.' Walker is shown in the photo above wearing an early partial pressure suit. This protected the pilot if cockpit pressure was lost above 50,000 feet. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on Jan. 25, 1946. Powered flights began in December 1946

  8. X-1E Engine Ground Test Run

    NASA Technical Reports Server (NTRS)

    1956-01-01

    The Bell Aircraft Corporation X-1E during a ground engine test run on the NACA High-Speed Flight Station ramp near the Rogers Dry Lake. The rocket technician is keeping the concrete cool by hosing it with water during the test. This also helps in washing away any chemicals that might spill. The test crew worked close to the aircraft during ground tests. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about

  9. X-1E canopy mock-up

    NASA Technical Reports Server (NTRS)

    1953-01-01

    This photo appears to depict the design of the X-1E canopy. In 1955, the X-1-2 was modified. The modifications included a new thin wing and a low-pressure fuel system. The most visible change was a raised canopy that replaced the original flush windshield on the aircraft, which was called the X-1E. The modified aircraft made its first glide flight on December 12, 1955, and its first powered flight three days later. Over a three-year period, the X-1E made a total of 26 flights, reaching a speed of Mach 2.24. National Advisory Committee for Aeronautics (NACA) pilot Joseph Walker was the pilot for flights 1 through 21, while John McKay made flights 22 to 26. The final flight occurred on November 6, 1958. This was also the last flight by an X-1 aircraft. On April 29, 1960, the X-1E was mounted on a pole in front of the Flight Research Center (FRC) headquarters building. In 1976 the FRC became the Hugh L. Dryden Flight Research Center, and the X-1E remained in front of the headquarters building. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many

  10. Understanding the Cray X1 System

    NASA Technical Reports Server (NTRS)

    Cheung, Samson

    2004-01-01

    This paper helps the reader understand the characteristics of the Cray X1 vector supercomputer system, and provides hints and information to enable the reader to port codes to the system. It provides a comparison between the basic performance of the X1 platform and other platforms that are available at NASA Ames Research Center. A set of codes, solving the Laplacian equation with different parallel paradigms, is used to understand some features of the X1 compiler. An example code from the NAS Parallel Benchmarks is used to demonstrate performance optimization on the X1 platform.

  11. 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).

  12. High time resolutions observations of Cygnus X-3 with EXOSAT

    NASA Astrophysics Data System (ADS)

    Berger, M.; van der Klis, M.

    1994-12-01

    We have studied the fast timing behavior of Cygnus X-3 using the entire EXOSAT ME dataset on this source, consisting of 22 observations that cover a total of 320 000 seconds. This large amount of data allowed us to measure the rapid (greater than 1 Hz) X-ray variability of the source to an unprecedented accuracy of 0.2% fractional rms amplitude. Above 256 Hz, the power of the X-ray count rate fluctuations is significantly below the level predicted from Poisson statistics modified by the known dead time processes in the instrument. We developed an improved empirical method for predicting the Poisson level in EXOSAT ME High Time Resolution 3 (HTR3) and HTR5 data, and use it in our present analysis. None of the four other X-ray sources studied had a weaker noise-component in the region 1-256 Hz as the power spectra of Cygnus X-3. An instrumental effect could therefore not be excluded. If the effect is instrumental, the 99% confidence upper limit on the 1-256 Hz rapid variability of Cygnus X-3 is 0.6% rms. The consequences of these results for previously reported EXOSAT HTR observations are briefly discussed. We compare our results to the predictions of the stellar wind model for Cygnus X-3. Monte Carlo simulations were carried out to investigate the signal-attenuating effect of the wind. For the most likely wind parameters, the intrinsic source variability is found to be either very strong (approximately 60% rms), unlike seen in any other X-ray source at similar luminosity, or to be less than or approximately 12%, which would be consistent with a black hole candidate in the high state, or a low magnetic field neutron star.

  13. Kinematics of Optical Filaments in the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    Greidanus, H.; Strom, R. G.

    We describe the kinematical character of optically emitting gas in a small area of the Cygnus Loop, as seen with moderately high resolution in Ha and [0III]. In both lines a number of different components contributing to the emission are recognized. The [0III] emission indicates that the gas may lie in a thin sheet, while from the Hα emission this indication is much less clear.

  14. Timing and Spectral Studies of the Peculiar X-ray Binary Circinus X-1

    SciTech Connect

    Saz Parkinson, Pablo M.

    2003-08-26

    Circinus X-1 (Cir X-1) is an X-ray binary displaying an array of phenomena which makes it unique in our Galaxy. Despite several decades of observation, controversy surrounds even the most basic facts about this system. It is generally classified as a Neutron Star (NS) Low Mass X-ray Binary (LMXB),though this classification is based primarily on the observation of Type I X-ray Bursts by EXOSAT in 1985. It is believed to be in a very eccentric {approx} 16.5 day orbit, displaying periodic outbursts in the radio and other frequency bands (including optical and IR) which reinforce the notion that this is in fact the orbital period. Cir X-1 lies in the plane of the Galaxy, where optical identification of the companion is made difficult due to dust obscuration. The companion is thought to be a low mass star, though a high mass companion has not currently been ruled out. In this work, the author analyzes recent observations of Cir X-1 made with the Unconventional Stellar Aspect (USA) experiment, as well as archival observations of Cir X-1 made by a variety of instruments, from as early as 1969. The fast (< 1 s) timing properties of Cir X-1 are studied by performing FFT analyses of the USA data. Quasi-Periodic Oscillations (QPOs) in the 1-50 Hz range are found and discussed in the context of recent correlations which question the leading models invoked for their generation. The energy dependence of the QPOs (rms increasing with energy) argues against them being generated in the disk and favors models in which the QPOs are related to a higher energy Comptonizing component. The power spectrum of Cir X-1 in its soft state is compared to that of Cygnus X-1 (Cyg X-1), the prototypical black hole candidate. Using scaling arguments the author argues that the mass of Cir X-1 could exceed significantly the canonical 1.4 M{circle_dot} mass of a neutron star, possibly partly explaining why this object appears so different to other neutron stars. The spectral evolution of Cir X-1 is

  15. 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

  16. Gemini H-band spectroscopy of the Galactic microquasar GRS 1915+105

    NASA Astrophysics Data System (ADS)

    McConnell, O.; Callanan, P.; Reynolds, M.

    2014-07-01

    Since its discovery in 1994 (Castro-Tirado 1994) GRS 1915+105 has become one of the most intensely studied of all the X-ray binaries in the Galaxy. This Galactic microquasar system is unique in that it has remained in outburst for the past 20 years: furthermore, initial measurements suggested a relatively high black hole mass of 14 ± 4 M_{⊙} (Greiner et al. 2001), outside the predicted mass range for such transients (Ozel et al. 2010). Here we present new Gemini H-band observations, and discuss the degree to which they can be used to refine the black hole mass in comparison to more recent estimates (Hurley et al 2013, Steeghs et al 2013). In addition, previous work found phase dependent emission of the CO bandheads in the K-band, and we present evidence of double peaked emission lines, indicative of ongoing mass transfer via the accretion disk.

  17. Accretion disc wind variability in the states of the microquasar GRS 1915+105

    NASA Astrophysics Data System (ADS)

    Neilsen, Joseph; Petschek, Andrew J.; Lee, Julia C.

    2012-03-01

    Continuing our study of the role and evolution of accretion disc winds in the microquasar GRS 1915+105, we present high-resolution spectral variability analysis of the β and γ states with the Chandra High-Energy Transmission Grating Spectrometer. By tracking changes in the absorption lines from the accretion disc wind, we find new evidence that radiation links the inner and outer accretion discs on a range of time-scales. As the central X-ray flux rises during the high-luminosity γ state, we observe the progressive overionization of the wind. In the β state, we argue that changes in the inner disc leading to the ejection of a transient 'baby jet' also quench the highly ionized wind from the outer disc. Our analysis reveals how the state, structure and X-ray luminosity of the inner accretion disc all conspire to drive the formation and variability of highly ionized accretion disc winds.

  18. X-1-2 on ramp

    NASA Technical Reports Server (NTRS)

    1951-01-01

    The Bell Aircraft Corporation X-1-2 aircraft on the ramp at NACA High Speed Flight Research Station located on the South Base of Muroc Army Air Field in 1947. The X-1-2 flew until October 23, 1951, completing 74 glide and powered flights with nine different pilots. The aircraft has white paint and the NACA tail band. The black Xs are reference markings for tracking purposes. They were widely used on NACA aircraft in the early 1950s. There were five versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on Jan. 25, 1946. Powered flights began in December 1946. On Oct. 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager

  19. VLBA "Movie" Gives Scientists New Insights On Workings of Mysterious Microquasars

    NASA Astrophysics Data System (ADS)

    2004-01-01

    Astronomers have made a 42-day movie showing unprecedented detail of the inner workings of a strange star system that has puzzled scientists for more than two decades. Their work is providing new insights that are changing scientists' understanding of the enigmatic stellar pairs known as microquasars. SS 433 Frame from SS 433 Movie: End to end is some 200 billion miles. CREDIT: Mioduszewski et al., NRAO/AUI/NSF Image Files Single Frame Overall Jet View (above image) VLBA Movie (animated gif, 2.3 MB) Animated graphic of SS 433 System (18MB) (Created using software by Robert Hynes, U.Texas) Annotated brightening graphic Unannotated brightening Frame 1 Unannotated brightening Frame 2 "This once-a-day series of exquisitely-detailed images is the best look anyone has ever had at a microquasar, and already has made us change our thinking about how these things work," said Amy Mioduszewski, of the National Radio Astronomy Observatory (NRAO), in Socorro, New Mexico. The astronomers used the National Science Foundation's Very Long Baseline Array (VLBA), a system of radio telescopes stretching from Hawaii to the Caribbean, to follow daily changes in a binary-star system called SS 433, some 15,000 light-years from Earth in the constellation Aquila. Mioduszewski worked with Michael Rupen, Greg Taylor and Craig Walker, all of NRAO. They reported their findings to the American Astronomical Society's meeting in Atlanta, Georgia. SS 433 consists of a neutron star or black hole orbited by a "normal" companion star. The powerful gravity of the neutron star or black hole is drawing material from the stellar wind of its companion into an accretion disk of material tightly circling the dense, central object prior to being pulled onto that object. This disk propels jets of subatomic particles outward from its poles. In SS 433, the particles in the jets move at 26 percent of the speed of light; in other microquasars, the jet material moves at 90-95 percent of light speed. The disk in SS

  20. Mid-Infrared and multi-wavelength monitoring of the microquasar GRS 1915+105.

    NASA Astrophysics Data System (ADS)

    Fuchs, Yael; Chaty, Sylvain; Dhawan, Vivek; Diana, Hannikainen; Mirabel, Felix; Pooley, Guy; Ribo, Marc; Rodriguez, Jerome; Rupen, Michael

    2005-06-01

    We propose to continue mid-infrared photometric and spectroscopic observations of the microquasar GRS 1915+105 in the context of a campaign of multi-wavelength observations of the source. GRS 1915+105 is used as a laboratory to understand the accretion / ejection phenomena occurring in stellar-mass accreting black hole (microquasars) and by analogy in supermassive black holes (AGNs). A key question is the nature of the time-variable infrared emission in this system. Depending on the state of the source, we wish to know what is the contribution in the mid-infrared of the different possible emission mechanisms: the thermal emission from the K-M giant donor star, the synchrotron emission from the compact relativistic jets, X-ray reprocessing in the accretion disc and free-free emission from a possible disc-wind. The continuum in a wavelength range as large as possible and the possible emission lines observed thanks to the Infrared Array Camera (IRAC) and the Infrared Spectrograph (IRS) are important clues to achieve this study. These mid-infrared observations will be combined with observations with the RXTE and INTEGRAL satellites in the X-rays and gamma-rays, the ESO/NTT in near-infrared and the VLA/VLBA and Ryle Telescopes in radio. Thanks to these simultaneous multiwavelength observations we will identify the accretion state of the source and determine the contribution of each emission component of the system. As GRS 1915+105 had been rarely observed in the mid-infrared range in the past, the Spitzer Space Telescope brings the unique opportunity to do so, shedding light on the physical mechanisms occurring in this particular binary system and which could apply to the other black hole binaries.

  1. Gamma-ray imaging observations of the Crab and Cygnus regions

    SciTech Connect

    McConnell, M.L.

    1987-01-01

    This dissertation presents the results from a balloon-borne experiment, referred to as the Directional Gamma-Ray Telescope (DGT), which is designed to image celestial gamma rays over the energy range 160 keV to 9.3 MeV. It utilizes a technique know as coded aperture imaging in order to obtain spatially resolved images of the sky with an angular resolution of 3.8/sup 0/. This detector is the first flight-ready instrument of this type operating at energies above 160 keV. The first successful balloon flight of this instrument took place on 1984 October 1-2. During the thirty hours in which the payload remained at float altitude, imaging observations of a number of sky regions were obtained, including observations of the Crab and Cygnus regions. The Crab Nebulapulsar was observed to have a featureless power-law spectrum, consistent with previous measurements. Emission from Cyg X-1 was observed up to approx. 10 MeV. At energies below 1 MeV, the data are consistent with a single-temperature inverse Compton model, with an electron temperature, kT/sub c/, of approx. 80 keV and an optical depth, r, of approx. 2.0.

  2. Analysis of the kinematic structure in the Cygnus OB1 association

    NASA Astrophysics Data System (ADS)

    Costado, M. T.; Alfaro, E. J.; González, M.; Sampedro, L.

    2017-03-01

    The Cygnus OB1 association is part of a larger star-forming complex located in the direction of Cygnus, but whose main sub-systems may be distributed at different distances from the sun. We have collected radial velocity (RV) data for more than 300 stars in an area of 5 x 5 squared degrees centered in the Cygnus OB1 association from the literature. This area also covers part of the Cygnus OB3 and OB9 associations, because of the diffuse limits between them. In this poster, we present the results of a clustering analysis in the subspace of the phase space formed by angular coordinates and RV in the field of the Cygnus OB1 association using the current available data. Three main groups have been detected corresponding to different RV and distances.

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

    NASA Astrophysics Data System (ADS)

    Naka, Tatsuhiro; Miuchi, Kentaro

    2013-12-01

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

  4. A giant radio flare from Cygnus X-3 with associated γ-ray emission: The 2011 radio and γ-ray flare of Cyg X-3

    SciTech Connect

    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.

    2012-04-10

    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 γ-ray emission, thanks to detections by Fermi Large Area Telescope (Fermi/LAT) and AGILE. In 2011, we observed Cyg X-3 in order to transit to a soft X-ray state, which is known to be associated with high-energy γ-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 (~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≥ 100 MeV) reveal renewed γ-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 γ-ray emission is not exclusively related to the rare giant radio flares. A three-week period of γ-ray emission is also detected when Cyg X-3 was weakly flaring in radio, right before transition to the radio quenched state. There were no γ-rays observed during the ~1-month long quenched state, when the radio flux is weakest. These results suggest transitions into and out of the ultrasoft X-ray (radio-quenched) state trigger γ-ray emission, implying a connection to the accretion process, and also that the γ-ray activity is related to the level of radio flux (and possibly shock formation), strengthening the connection to the relativistic jets.

  5. A giant radio flare from Cygnus X-3 with associated γ-ray emission: The 2011 radio and γ-ray flare of Cyg X-3

    DOE PAGES

    Corbel, S.; Dubus, G.; Tomsick, J. A.; ...

    2012-04-10

    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 γ-ray emission, thanks to detections by Fermi Large Area Telescope (Fermi/LAT) and AGILE. In 2011, we observed Cyg X-3 in order to transit to a soft X-ray state, which is known to be associated with high-energy γ-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 (~20more » Jy) optically thin radio flare marks the end of the quenched state, accompanied by rising non-thermal hard X-rays. Fermi/LAT observations (E≥ 100 MeV) reveal renewed γ-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 γ-ray emission is not exclusively related to the rare giant radio flares. A three-week period of γ-ray emission is also detected when Cyg X-3 was weakly flaring in radio, right before transition to the radio quenched state. There were no γ-rays observed during the ~1-month long quenched state, when the radio flux is weakest. These results suggest transitions into and out of the ultrasoft X-ray (radio-quenched) state trigger γ-ray emission, implying a connection to the accretion process, and also that the γ-ray activity is related to the level of radio flux (and possibly shock formation), strengthening the connection to the relativistic jets.« less

  6. X-1A with pilot Joe Walker

    NASA Technical Reports Server (NTRS)

    1955-01-01

    Cowboy Joe (NACA High-Speed Flight Station test pilot Joseph Walker) and his steed (Bell Aircraft Corporation X-1A) A happy Joe was photographed in 1955 at Edwards, California. The X-1A was flown six times by Bell Aircraft Company pilot Jean 'Skip' Ziegler in 1953. Air Force test pilots Maj. Charles 'Chuck' Yeager and Maj. Arthur 'Kit' Murray made 18 flights between 21 November 1953 and 26 August 1954. The X-1A was then turned over to the NACA. Joe Walker piloted the first NACA flight on 20 July 1955. Walker attemped a second flight on 8 August 1955, but an explosion damaged the aircraft just before launch. Walker, unhurt, climbed back into the JTB-29A mothership, and the X-1A was jettisoned over the Edwards AFB bombing range.

  7. AR1429 Releases X1 Class Flare

    NASA Image and Video Library

    The Solar Dynamics Observatory captured the X1 flare, shown here in the 171 Angstrom wavelength, a wavelength typically shown in the color gold. This movie runs from 10 PM ET March 4 to 3 AM March ...

  8. On the nature of SMC X-1.

    NASA Astrophysics Data System (ADS)

    Li, X.-D.; van den Heuvel, E. P. J.

    1997-05-01

    The 0.71 s X-ray pulsar SMC X-1 has some distinct features from other X-ray pulsars. It maintained a stable spin-up though in X-rays both low- and high-intensity states have been observed. An X-ray burst was discovered from SMC X-1, and was probably generated by an instability in the accretion flow. Using the modified magnetically threaded accretion disk theory, we have estimated the magnetic moment of SMC X-1 to be ~10^29^G.cm^3^, which is lower than those of other typical X-ray pulsars (e.g., Her X-1, Vela X-1) by an order of magnitude. Comparing SMC X-1 with the new transient X-ray pulsar GRO J1744-28, from which type II bursts were recently discovered, we suggest that the nature of this type of "bursting pulsars" may be accounted for by their relatively low magnetic moments and high accretion rates, if the burst from SMC X-1 is really due to spasmodic accretion as those from GRO J1744-28. The inner edge of the accretion disk in both X-ray sources is found to lie in the transition region at which the radiation pressure becomes comparable to the gas pressure, suggesting that the bursts from both sources may be related to the Lightman-Eardley instability in the inner region of the disk. The difference between the one burst from SMC X-1 and the many bursts from GRO J1744-28 is discussed, and may originate from the different magnetic field structure in these two X-ray pulsars.

  9. Highly Structured Wind in Vela X-1

    NASA Technical Reports Server (NTRS)

    Kreykenbohm, Ingo; Wilms, Joern; Kretschmar, Peter; Torrejon, Jose Miguel; Pottschmidt, Katja; Hanke, Manfred; Santangelo, Andrea; Ferrigno, Carlo; Staubert, Ruediger

    2008-01-01

    We present an in-depth analysis of the spectral and temporal behavior of a long almost uninterrupted INTEGRAL observation of Vela X-1 in Nov/Dec 2003. In addition to an already high activity level, Vela X-1 exhibited several very intense flares with a maximum intensity of more than 5 Crab in the 20 40 keV band. Furthermore Vela X-1 exhibited several off states where the source became undetectable with ISGRI. We interpret flares and off states as being due to the strongly structured wind of the optical companion: when Vela X-1 encounters a cavity in the wind with strongly reduced density, the flux will drop, thus potentially triggering the onset of the propeller effect which inhibits further accretion, thus giving rise to the off states. The required drop in density to trigger the propeller effect in Vela X-1 is of the same order as predicted by theoretical papers for the densities in the OB star winds. The same structured wind can give rise to the giant flares when Vela X-1 encounters a dense blob in the wind. Further temporal analysis revealed that a short lived QPO with a period of 6800 sec is present. The part of the light curve during which the QPO is present is very close to the off states and just following a high intensity state, thus showing that all these phenomena are related.

  10. Giant Radio Flare of Cygnus X-3 in September 2016

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

    In the long-term multi-frequency monitoring program of the microquasars with RATAN-600 we discovered the giant flare from X-ray binary Cyg X-3 on 13 September 2016. It happened after 2000 days of the 'quiescent state' of the source passed after the former giant flare (˜18 Jy) in March 2011. We have found that during this quiet period the hard X-ray flux (Swift/BAT, 15-50 keV) and radio flux (RATAN-600, 11 GHz) have been strongly anti-correlated. Both radio flares occurred after transitions of the microquasar to a 'hypersoft' X-ray state that occurred in February 2011 and in the end of August 2016. The giant flare was predicted by us in the first ATel (Trushkin et al. (2016)). Indeed after dramatic decrease of the hard X-ray Swift 15-50 keV flux and RATAN 4- 11 GHz fluxes (a 'quenched state') a small flare (0.7 Jy at 4-11 GHz) developed on MJD 57632 and then on MJD 57644.5 almost simultaneously with X-rays radio flux rose from 0.01 to 15 Jy at 4.6 GHz during few days. The rise of the flaring flux is well fitted by a exponential law that could be a initial phase of the relativistic electrons generation by internal shock waves in the jets. Initially spectra were optically thick at frequencies lower 2 GHz and optically thin at frequencies higher 8 GHz with typical spectral index about -0.5. After maximum of the flare radio fluxes at all frequencies faded out with exponential law.

  11. 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.

  12. Optical kinematics in the Cygnus Loop. I - Observations

    NASA Astrophysics Data System (ADS)

    Greidanus, H.; Strom, R. G.

    1991-07-01

    The small-scale radial-velocity structure of optical filaments in the Cygnus Loop supernova remnant was mapped in the H-alpha and forbidden O III 5007-A emission lines with a resolution of 6 arcsec spatially and 24 km/s in radial velocity. The imaging Fabry-Perot interferometer Taurus was used, and some aspects of velocity calibration are discussed. The calibrated data, in the form of 3D matrices of intensity as a function of sky position and radial velocity, are presented here as position-velocity cross-cuts, and as total intensity and radial velocity maps.

  13. An H I absorbing circumnuclear disk in Cygnus A

    NASA Astrophysics Data System (ADS)

    Struve, C.; Conway, J. E.

    2010-04-01

    We present Very Long Baseline Array (VLBA) H i absorption observations of the core region of the powerful radio galaxy Cygnus A. These data show both broad (FWHM = 231 ± 21 km s-1) and narrow (FWHM < 30 km s-1) velocity width absorption components. The broad velocity absorption shows high opacity on the counter-jet, low opacity against the core and no absorption on the jet side. We argue that these results are most naturally explained by a circumnuclear H i absorbing disk orientated roughly perpendicular to the jet axis. We estimate that the H i absorbing gas lies at a radius of ˜80 pc has a scale height of about 20 pc, density n > 104 cm-3 and total column density in the range 1023 - 1024 cm-2. Models in which the H i absorption is primarily from an atomic or a molecular gas phase can both fit our data. Modelling taking into account the effective beam shows that the broad H i absorbing gas component does not cover the radio core in Cygnus A and therefore does not contribute to the gas column that blocks our view of the hidden quasar nucleus. If however Cygnus A were observed from a different direction, disk gas on ~ 100 pc radius scales would contribute significantly to the nuclear column density, implying that in some radio galaxies gas on these scales may contribute to the obscuration of the central engine. We argue that the circumnuclear torus in Cygnus A contains too little mass to power the AGN over > 107 yr but that material in the outer H i absorbing gas disk can provide a reservoir to fuel the AGN and replenish torus clouds. The second narrow H i absorption component is significantly redshifted (by 186 km s-1) with respect to the systemic velocity and probably traces infalling gas which will ultimately fuel the source. This component could arise either within a tidal tail structure associated with a recent (minor) merger or be associated with an observed infalling giant molecular cloud.

  14. X-1 research aircraft landing on lakebed

    NASA Technical Reports Server (NTRS)

    1947-01-01

    The first of the rocket-powered research aircraft, the X-1 (originally designated the XS-1), was a bullet-shaped airplane that was built by the Bell Aircraft Company for the US Air Force and the National Advisory Committee on Aeronautics (NACA). The mission of the X-1 was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier'. The first of the three X-1s was glide-tested at Pinecastle Air Force Base, FL, in early 1946. The first powered flight of the X-1 was made on Dec. 9, 1946, at Edwards Air Force Base with Chalmers Goodlin, a Bell test pilot, at the controls. On Oct. 14, 1947, with USAF Captain Charles 'Chuck' Yeager as pilot, the aircraft flew faster than the speed of sound for the first time. Captain Yeager ignited the four-chambered XLR-11 rocket engines after being air-launched from under the bomb bay of a B-29 at 21,000 ft. The 6,000-lbthrust ethyl alcohol/liquid oxygen burning rockets, built by Reaction Motors, Inc., pushed him up to a speed of 700 mph in level flight. Captain Yeager was also the pilot when the X-1 reached its maximum speed of 957 mph. Another USAF pilot. Lt. Col. Frank Everest, Jr., was credited with taking the X-1 to its maximum altitude of 71,902 ft. Eighteen pilots in all flew the X-1s. The number three plane was destroyed in a fire before ever making any powered flights. A single-place monoplane, the X-1 was 31 ft long, 10 ft high, and had a wingspan of 29 ft. It weighed 4,900 lb and carried 8,200 lb of fuel. It had a flush cockpit with a side entrance and no ejection seat. This roughly 30-second video clip shows the X-1 landing on Rogers Dry Lakebed followed by the safety chase aircraft.

  15. X-1 launch from B-29 mothership

    NASA Technical Reports Server (NTRS)

    1947-01-01

    The first of the rocket-powered research aircraft, the X-1 (originally designated the XS-1), was a bullet-shaped airplane that was built by the Bell Aircraft Company for the US Air Force and the National Advisory Committee on Aeronautics (NACA). The mission of the X-1 was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier'. The first of the three X-1s was glide-tested at Pinecastle Air Force Base, FL, in early 1946. The first powered flight of the X-1 was made on Dec. 9, 1946, at Edwards Air Force Base with Chalmers Goodlin, a Bell test pilot, at the controls. On Oct. 14, 1947, with USAF Captain Charles 'Chuck' Yeager as pilot, the aircraft flew faster than the speed of sound for the first time. Captain Yeager ignited the four-chambered XLR-11 rocket engines after being air-launched from under the bomb bay of a B-29 at 21,000 ft. The 6,000-lb thrust ethyl alcohol/liquid oxygen burning rockets, built by Reaction Motors, Inc., pushed him up to a speed of 700 mph in level flight. Captain Yeager was also the pilot when the X-1 reached its maximum speed of 957 mph. Another USAF pilot. Lt. Col. Frank Everest, Jr., was credited with taking the X-1 to its maximum altitude of 71,902 ft. Eighteen pilots in all flew the X-1s. The number three plane was destroyed in a fire before ever making any powered flights. A single-place monoplane, the X-1 was 31 ft long, 10 ft high, and had a wingspan of 29 ft. It weighed 4,900 lb and carried 8,200 lb of fuel. It had a flush cockpit with a side entrance and no ejection seat. This roughly 30-second video clip shows the X-1 launched from a B-29, ignition of the XLR-11 rocket engine, and the succeeding flight, including a roll. At one point, the video shows observers of the flight from the ground.

  16. Mid-Infrared and multi-wavelength monitoring of the microquasar GRS 1915+105.

    NASA Astrophysics Data System (ADS)

    Fuchs, Yael; Chaty, Sylvain; Diana, Hannikainen; Mirabel, Felix; Rodriguez, Jerome

    2004-09-01

    We propose mid-infrared photometric and spectroscopic observations of the microquasar GRS 1915+105 in the context of a multi-wavelength follow-up campaign of the source. GRS 1915+105 is used as a laboratory to understand the accretion / ejection phenomena occurring in stellar-mass accreting black hole (microquasars) and by analogy in supermassive black holes (AGNs). A key question is the nature of the time-variable infrared emission in this system. Depending on the state of the source, we wish to know what is the contribution in the mid-infrared of the different possible emission mechanisms: the thermal emission from the K-M giant donor star, the synchrotron emission from the compact relativistic jets, X-ray reprocessing in the accretion disc and free-free emission from a dense wind. A particular contribution of the Spitzer Telescope will be the observation of this dense wind in GRS 1915+105, which is very difficult to detect in X-ray spectra due to pile-up phenomena in X-ray detectors. The continuum in a wavelength range as large as possible and the possible emission lines observed thanks to the Infrared Array Camera (IRAC) and the Infrared Spectrograph (IRS) are important clues to achieve this study. These mid-infrared observations will be combined with observations with the RXTE and INTEGRAL satellites in the X-rays and gamma-rays, the ESO/NTT in near-infrared and the Ryle Telescope in radio. Thanks to these simultaneous multiwavelength observations we will identify the accretion state of the source and determine the contribution of each emission component of the system. As GRS 1915+105 had been rarely observed in the mid-infrared range in the past, the Spitzer Space Telescope will bring the unique opportunity to do so, shedding light on the physical mechanisms occurring in this particular binary system and which could apply to the other black hole binaries.

  17. Cygnus Arrives Safely to ISS on This Week @NASA – October 28, 2016

    NASA Image and Video Library

    2016-10-28

    On Oct. 23, Orbital ATK’s Cygnus cargo spacecraft safely arrived at the International Space Station – six days after being launched on an Antares rocket from NASA’s Wallops Flight Facility, in Virginia. The successful trip to orbit is the return of rocket launches to the space station from Virginia, following the loss of an Antares and a Cygnus spacecraft during a launch mishap in October 2014. The Cygnus delivered more than 5,100 pounds of science investigations, food and supplies to the crew onboard the station. Also, Next Space Station Crew Trains in Russia, Solar Hazards in Exploration, Preparing for Orion Water Recovery Test and more!

  18. Study of underground muons during the January 1991 radio flare of Cygnus X-3

    SciTech Connect

    Becker-Szendy, R.; Bratton, C.B.; Casper, D.; Dye, S.T.; Gajewski, W.; Goldhaber, M.; Haines, T.J.; Halverson, P.G.; Kielczewska, D.; Kropp, W.R.; Learned, J.G.; LoSecco, J.M.; Matsuno, S.; McGrath, G.; McGrew, C.; Miller, R.S.; Price, L.; Reines, F.; Schultz, J.; Sobel, H.W.; Stone, J.L.; Sulak, L.R.; Svoboda, R. Brookhaven National Laboratory, Upton, New York 11973 Boston University, Boston, Massachusetts 02215 Cleveland State University, Cleveland, Ohio 44115 The University of Hawaii, Honolulu, Hawaii 96822 Louisiana State University, Baton Rouge, Louisiana 70803 The University of Maryland, College Park, Maryland 20742 The University of Notre Dame, Notre Dame, Indiana 46556 Warsaw University, Warsaw )

    1993-05-15

    Muons recorded by the IMB proton decay detector during the radio outburst from Cygnus X-3 in January 1991 are studied. Data are examined for both aperiodic excesses and those phase modulated at the x-ray period of Cygnus X-3. No correlation between the muon data and Cygnus X-3 is found. Further, this observation provides flux limits of [Phi][sub 90%] C.L.[le]2[times]10[sup [minus]10] [mu] cm[sup [minus]2]s[sup [minus]1] at 1570 meters of water equivalent on the 20th and 23rd, in contrast with other reported signals.

  19. NICER Observations of Serpens X-1

    NASA Astrophysics Data System (ADS)

    Miller, Jon M.

    2017-08-01

    Relativistic emission lines from the inner disk can be used to set an upper limit on the radius of accreting neutron stars. Serpens X-1 is a neutron star X-ray binary wherein a strong, skewed Fe K emission line and broadband disk reflection spectrum have been observed. The ability of NICER to observe bright sources and to extend spectra down to 0.2 keV means that relativistic lines from low-Z elements may become readily accessible in sources like Serpens X-1, potentially leading to tighter constraints on neutron star radii. Here, we report on early observations of Serpens X-1 with NICER, with specific attention to the low energy spectrum, disk reflection, and derived radii.

  20. Cray X1 Evaluation Status Report

    SciTech Connect

    Vetter, J.S.

    2004-02-09

    On August 15, 2002 the Department of Energy (DOE) selected the Center for Computational Sciences (CCS) at Oak Ridge National Laboratory (ORNL) to deploy a new scalable vector supercomputer architecture for solving important scientific problems in climate, fusion, biology, nanoscale materials and astrophysics. ''This program is one of the first steps in an initiative designed to provide U.S. scientists with the computational power that is essential to 21st century scientific leadership,'' said Dr. Raymond L. Orbach, director of the department's Office of Science The Cray X1 is an attempt to incorporate the best aspects of previous Cray vector systems and massively-parallel-processing (MPP) systems into one design. Like the Cray T90, the X1 has high memory bandwidth, which is key to realizing a high percentage of theoretical peak performance. Like the Cray T3E, the X1 has a high-bandwidth, low-latency, scalable interconnect, and scalable system software. And, like the Cray SV1, the X1 leverages commodity off-the-shelf (CMOS) technology and incorporates non-traditional vector concepts, like vector caches and multi-streaming processors. In FY03, CCS procured a 256-processor Cray X1 to evaluate the processors, memory subsystem, scalability of the architecture, software environment and to predict the expected sustained performance on key DOE applications codes. The results of the micro-benchmarks and kernel benchmarks show the architecture of the Cray X1 to be exceptionally fast for most operations. The best results are shown on large problems, where it is not possible to fit the entire problem into the cache of the processors. These large problems are exactly the types of problems that are important for the DOE and ultra-scale simulation.

  1. ADDITIONAL MASSIVE BINARIES IN THE CYGNUS OB2 ASSOCIATION

    SciTech Connect

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

    2012-03-01

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

  2. 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.

  3. Adaptive optics observations of the core of Cygnus A

    NASA Astrophysics Data System (ADS)

    Max, C. E.; Whysong, D.; Antonucci, R.; Canalizo, G.; Macintosh, B. A.; Stockton, A.

    2001-12-01

    We report on near-infrared imaging and spectroscopy of the core of Cygnus A, using adaptive optics systems at the Lick and Keck Observatories. In our images, a V-shaped ionization cone structure is seen to the south-east of the nucleus, as in previous HST NICMOS observations. To the north-west of the nucleus are two diffuse emission regions. We have obtained K-band spectra of these regions and of the nucleus. Paschen alpha spectra show emission near the nucleus with FWHM 1000 km/s. The diffuse emission regions to the north-west and south-east have narrower linewidths. We interpret these data in terms of models for the core of Cygnus A. This work was performed under the auspices of the U.S. Department of Energy, National Nuclear Security Administration by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48, and was supported in part by the National Science Foundation Science and Technology Center for Adaptive Optics, managed by the University of California at Santa Cruz under cooperative agreement No. AST - 9876783.

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

    NASA Astrophysics Data System (ADS)

    Marshak, M. L.

    1992-02-01

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

  5. SUZAKU OBSERVATIONS OF THE GALACTIC CENTER MICROQUASAR 1E 1740.7-2942

    SciTech Connect

    Reynolds, Mark T.; Miller, Jon M.

    2010-06-20

    We present two Suzaku observations of the Galactic center microquasar 1E 1740.7-2942 separated by approximately 700 days. The source was observed on both occasions after a transition to the spectrally hard state. Significant emission from 1E 1740.7-2942 is detected out to an energy of 300 keV, with no spectral break or turnover evident in the data. We tentatively measure a lower limit to the cutoff energy of {approx}380 keV. The spectra are found to be consistent with a Comptonized corona on both occasions, where the high energy emission is consistent with a hard power-law ({Gamma} {approx} 1.8) with a significant contribution from an accretion disk with a temperature of {approx}0.4 keV at soft X-ray energies. The measured value for the inner radius of the accretion disk is found to be inconsistent with the picture whereby the disk is truncated at large radii in the low-hard state and instead favors a radius close to the ISCO (R{sub in} {approx} 10 - 20 R{sub g}).

  6. High-mass microquasars and low-latitude gamma-ray sources

    NASA Astrophysics Data System (ADS)

    Bosch-Ramon, V.; Romero, G. E.; Paredes, J. M.

    2005-01-01

    Population studies of unidentified EGRET sources suggest that there exist at least three different populations of galactic gamma-ray sources. One of these populations is formed by young objects distributed along the galactic plane with a strong concentration toward the inner spiral arms of the Galaxy. Variability, spectral and correlation analysis indicate that this population is not homogeneous. In particular, there is a subgroup of sources that display clear variability in their gamma-ray fluxes on timescales from days to months. Following the proposal by Kaufman Bernadó et al. (2002), we suggest that this group of sources might be high-mass microquasars, i.e. accreting black holes or neutron stars with relativistic jets and early-type stellar companions. We present detailed inhomogeneous models for the gamma-ray emission of these systems that include both external and synchrotron self-Compton interactions. We have included effects of interactions between the jet and all external photon fields to which it is exposed: companion star, accretion disk, and hot corona. We make broadband calculations to predict the spectral energy distribution of the emission produced in the inner jet of these objects up to GeV energies. The results and predictions can be tested by present and future gamma-ray instruments like INTEGRAL, AGILE, and GLAST.

  7. Relativistic Iron Emission and Disk Reflection in Galactic Microquasar XTE J1748-288

    NASA Technical Reports Server (NTRS)

    Miller, J. M.; Fox, D. W.; Matteo, T. DI; Wijnands, R.; Belloni, T.; Pooley, D.; Kouveliotou, C.; Lewin, W. H. G.

    2001-01-01

    We report evidence for an Fe K(alpha) fluorescence line feature and disk reflection in the very high, high-, and low-state X-ray spectra of the Galactic microquasar XTE J1748-288 during its 1998 June outburst. Spectral analyses are made on data gathered throughout the outburst by the Rossi X-Ray Timing Explorer Proportional Counter Array. Gaussian line, relativistic disk emission line, and ionized disk reflection models are fitted to the data. In the very high state the line profile appears strongly redshifted, consistent with disk emission from the innermost stable orbits around a maximally rotating Kerr black hole. In the high state the line profile is less redshifted and increasingly prominent. The low-state line profile is very strong (approx. 0.5 keV equivalent width) and centered at 6.7 +/- 0.10 keV; disk line emission model fits indicate that the inner edge of the disk fluctuates between approx. 20Rg and approx. 100Rg in this state. The disk reflection fraction is traced through the outburst; reflection from an ionized disk is preferred in the very high and high states, and reflection from a relatively neutral disk is preferred in the low state. We discuss the implications of our findings for the binary system dynamics and accretion flow geometry in XTE J1748-288.

  8. Relativistically Skewed Iron Emission and Disk Reflection in Galactic Microquasar XTE J1748-288

    NASA Technical Reports Server (NTRS)

    Miller, J. M.; Fox, D. W.; DiMatteo, T.; Wijnands, R.; Belloni, T.; Kouveliotou, C.; Lewin, W. H. G.

    2000-01-01

    We report evidence for an Fe K-alpha fluorescence line feature in the Very High, High, and Low state X-ray spectra of the galactic microquasar XTE JI748-288 during its June 1998 outburst. Spectral analyses were made on observations spread across the outburst, gathered with the Rossi X-ray Timing Explorer. Gaussian line. disk emission line, relativistic disk emission line, and disk reflection models are fit to the data. In the Very High State, the line profile is strongly redshifted and consistent with emission from the innermost radius of a maximally rotating Kerr black hole, 1.235 R(sub g). The line profile is less redshifted in the High State, but increasingly prominent. In the Low State, the line profile is very strong and centered af approx. 6.7 keV; disk line emission models constrain the inner edge of the disk to fluctuate between approx.20 and approx.59 R(sub g). We trace the disk reflection fraction across the full outburst of this source, and find well-constrained fractions below those observed in AGN in the Very High and High States, but consistent with other galactic sources in the Low State. We discuss the possible implications for black hole X-ray binary system dynamics and accretion flow geometry.

  9. Relativistic Iron Emission and Disk Reflection in Galactic Microquasar XTE J1748-288

    NASA Technical Reports Server (NTRS)

    Miller, J. M.; Fox, D. W.; DiMatteo, T.; Wijnands, R.; Belloni, T.; Pooley, D.; Kouveliotou, C.; Lewin, W. H. G.

    2001-01-01

    We report evidence for an Fe K-alpha fluorescence line feature and disk reflection in the very high, high-, and low-state X-ray spectra of the Galactic microquasar XTE J1748 - 288 during its 1998 June outburst. Spectral analyses are made on data gathered throughout the outburst by the Rossi X-Ray Timing Explorer Proportional Counter Array. Gaussian line, relativistic disk emission line, and ionized disk reflection models are fitted to the data. In the very high state the line profile appears strongly redshifted, consistent with disk emission from the innermost stable orbits around a maximally rotating Kerr black hole. In the high state the line profile is less redshifted and increasingly prominent. The low-state line profile is very strong (approx. 0.5 keV equivalent width) and centered at 6.7 +/- 0.10 keV; disk line emission model fits indicate that the inner edge of the disk fluctuates between approx. 20R(sub g) and - approx. 100R(sub g) in this state. The disk reflection fraction is traced through the outburst; reflection from an ionized disk is preferred in the very high and high states, and reflection from a relatively neutral disk is preferred in the low state. We discuss the implications of our findings for the binary system dynamics and accretion flow geometry in XTE J1748 - 288.

  10. MAGIC observations of the microquasar V404 Cygni during the 2015 outburst

    NASA Astrophysics Data System (ADS)

    Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Arcaro, C.; Babić, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Berti, A.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Carosi, R.; Carosi, A.; Chatterjee, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Cumani, P.; da Vela, P.; Dazzi, F.; de Angelis, A.; de Lotto, B.; de Oña Wilhelmi, E.; di Pierro, F.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Engelkemeier, M.; Fallah Ramazani, V.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Giammaria, P.; Godinović, N.; Gora, D.; Griffiths, S.; Guberman, D.; Hadasch, D.; Hahn, A.; Hassan, T.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Hughes, G.; Ishio, K.; Konno, Y.; Kubo, H.; Kushida, J.; Kuveždić, D.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; Maggio, C.; Majumdar, P.; Makariev, M.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Minev, M.; Mirzoyan, R.; Moralejo, A.; Moreno, V.; Moretti, E.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Ninci, D.; Nishijima, K.; Noda, K.; Nogués, L.; Paiano, S.; Palacio, J.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Pedaletti, G.; Peresano, M.; Perri, L.; Persic, M.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Garcia, J. R.; Reichardt, I.; Rhode, W.; Ribó, M.; Rico, J.; Saito, T.; Satalecka, K.; Schroeder, S.; Schweizer, T.; Sillanpää, A.; Sitarek, J.; Šnidarić, I.; Sobczynska, D.; Stamerra, A.; Strzys, M.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Torres, D. F.; Torres-Albà, N.; Treves, A.; Vanzo, G.; Vazquez Acosta, M.; Vovk, I.; Ward, J. E.; Will, M.; Zarić, D.; MAGIC Collaboration; Loh, A.; Rodriguez, J.

    2017-10-01

    The microquasar V404 Cygni underwent a series of outbursts in 2015, June 15-31, during which its flux in hard X-rays (20-40 keV) reached about 40 times the Crab nebula flux. Because of the exceptional interest of the flaring activity from this source, observations at several wavelengths were conducted. The MAGIC telescopes, triggered by the INTEGRAL alerts, followed-up the flaring source for several nights during the period June 18-27, for more than 10 h. One hour of observation was simultaneously conducted on a giant 22 GHz radio flare and a hint of signal at GeV energies seen by Fermi-LAT. The MAGIC observations did not show significant emission in any of the analysed time intervals. The derived flux upper limit, in the energy range 200-1250 GeV, is 4.8 × 10-12 photons cm-2 s-1. We estimate the gamma-ray opacity during the flaring period, which along with our non-detection points to an inefficient acceleration in the V404 Cyg jets if a very high energy emitter is located further than 1 × 1010 cm from the compact object.

  11. Variable-Frequency QPOs from the Galactic Microquasar GRS 1915+105

    NASA Technical Reports Server (NTRS)

    Markwardt, Craig B.; Swank, Jean H.; Taam, Ronald E.

    1998-01-01

    We show that the galactic microquasar GRS 1915+105 exhibits quasi-periodic oscillations (QPOS) whose frequency varies continuously from 1-15 Hz, during spectrally hard dips when the source is in a flaring state. NN'e report here analyses of simultaneous energy spectra and power density spectra at 4 s intervals. The energy spectrum is well fit at each time step by an optically thick accretion disk plus power law model, while the power density spectrum consists of a varying red noise component plus the variable frequency QPO. The features of both spectra are strongly correlated with one another. The 1-15 Hz QPOs appear when the power law component becomes hard and intense, and themselves have an energy spectrum consistent with the power law component (with root mean square amplitudes as high as 10%). The frequency of the oscillations, however, is most strikingly correlated with the parameters of the thermal disk component. The tightest correlation is between QPO frequency and the disk X-ray flux. This fact indicates that the properties of the QPO are not determined by solely a disk or solely a corona.

  12. THE DISTANCE, INCLINATION, AND SPIN OF THE BLACK HOLE MICROQUASAR H1743-322

    SciTech Connect

    Steiner, James F.; McClintock, Jeffrey E.; Reid, Mark J.

    2012-01-20

    During its 2003 outburst, the black hole X-ray transient H1743-322 produced two-sided radio and X-ray jets. Applying a simple and symmetric kinematic model to the trajectories of these jets, we determine the source distance, 8.5 {+-} 0.8 kpc, and the inclination angle of the jets, 75 Degree-Sign {+-} 3 Degree-Sign . Using these values, we estimate the spin of the black hole by fitting its Rossi X-ray Timing Explorer spectra, obtained during the 2003 outburst, to a standard relativistic accretion-disk model. For its spin, we find a{sub *} = 0.2 {+-} 0.3 (68% limits), -0.3 < a{sub *} < 0.7 at 90% confidence. We strongly rule against an extreme value of spin: a{sub *} < 0.92 at 99.7% confidence. H1743-322 is the third known microquasar (after A0620-00 and XTE J1550-564) that displays large-scale ballistic jets and has a moderate value of spin. Our result, which depends on an empirical distribution of black hole masses, takes into account all known sources of measurement error.

  13. THE VARIABLE NEAR-INFRARED COUNTERPART OF THE MICROQUASAR GRS 1758–258

    SciTech Connect

    Luque-Escamilla, Pedro L.

    2014-12-10

    We present a new study of the microquasar system GRS 1758–258 in the near-infrared domain based on archival observations with the Hubble Space Telescope and the NICMOS camera. In addition to confirming the near-infrared counterpart pointed out by Muñoz-Arjonilla et al., we show that this object displays significant photometric variability. From its average magnitudes, we also find that GRS 1758–258 fits well within the correlation between the optical/near-infrared and X-ray luminosity known to exist for low-mass, black-hole candidate X-ray binaries in a hard state. Moreover, the spectral energy distribution built using all radio, near-infrared, and X-ray data available closest in time to the NICMOS observations can be reasonably interpreted in terms of a self-absorbed radio jet and an irradiated accretion disk model around a stellar-mass black hole. All these facts match the expected behavior of a compact binary system and strengthen our confidence in the counterpart identification.

  14. Inflow and outflow from the accretion disc of the microquasar SS433: UKIRT spectroscopy

    NASA Astrophysics Data System (ADS)

    Perez M., Sebastian; Blundell, Katherine M.

    2009-08-01

    A succession of near-infrared (near-IR) spectroscopic observations, taken nightly throughout an entire cycle of SS433's orbit, reveal (i) the persistent signature of SS433's accretion disc, having a rotation speed of ~500kms-1, (ii) the presence of circumbinary disc recently discovered at optical wavelengths by Blundell, Bowler & Schmidtobreick (2008) and (iii) a much faster outflow than has previously been measured for the disc wind, with a terminal velocity of ~1500kms-1. The increased wind terminal velocity results in a mass-loss rate of ~10-4Msolaryr-1. These, together with the newly (upwardly) determined masses for the components of the SS433 system, result in an accurate diagnosis of the extent to which SS433 has super-Eddington flows. Our observations imply that the size of the companion star is comparable with the semiminor axis of the orbit which is given by , where e is the eccentricity. Our relatively spectral resolution at these near-IR wavelengths has enabled us to deconstruct the different components that comprise the Brackett-γ (Brγ) line in this binary system, and their physical origins. With this line being dominated throughout our series of observations by the disc wind, and the accretion disc itself being only a minority (~15 per cent) contribution, we caution against use of the unresolved Brγ line intensity as an `accretion signature' in X-ray binaries or microquasars in any quantitative way.

  15. Disk-Jet Connection in the Microquasar GRS 1915+105 and Infrared and Radio Emission

    NASA Astrophysics Data System (ADS)

    Yadav, J. S.

    2001-02-01

    We present evidence of a direct accretion disk-jet connection in the Galactic microquasar GRS 1915+105 based on our analysis of RXTE/PCA data with a ``spike'' in X-ray light curves. We find that the radio emission increases as the hardness ratio increases during the low hard state. We suggest that the ``spike,'' which separates the dips with hard and soft spectra, marks the beginning of the burst phase when the luminosity of the soft X-rays (5-15 keV) increases by a large factor (~10). This produces a major ejection episode of the synchrotron-emitting plasma termed as ``baby jets,'' which are associated with infrared (IR) and radio flares of about half an hour period widely reported in the literature. Subsequent short but frequent soft dips produce overlapping faint flares which result in an enhanced level of quasi-steady emission. We discuss the differences between ``baby jets'' and relativistic radio jets and especially investigate their signatures in X-rays.

  16. Optical Outburst of AQL X-1

    NASA Astrophysics Data System (ADS)

    Jain, R.; Bailyn, C.; Garcia, M.; Rines, K.; Levine, A.; Espinoza, J.; Gonzalez, D.

    1999-05-01

    We report YALO consortium observations using the Yale 1-m telescope at CTIO and observations with the 48" telescope at the Whipple Observatory: Aql X-1 = V1333 Aql appears to be beginning a new outburst. This x-ray binary outbursts approximately once per year, and based on its recent outbursts was due to erupt.

  17. NACA Aircraft on Lakebed - D-558-2, X-1B, and X-1E

    NASA Technical Reports Server (NTRS)

    1955-01-01

    Early NACA research aircraft on the lakebed at the High Speed Research Station in 1955: Left to right: X-1E, D-558-2, X-1B There were four versions of the original Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and an altitude of 43,000 feet. The number 2 X-1 was modified and redesignated the X-1E. The modifications included adding a conventional canopy, an ejection seat, a low-pressure fuel system

  18. Why is Cygnus X-3 (with related sources) a highlight of cosmic-ray astrophysics?

    NASA Technical Reports Server (NTRS)

    Hillas, A. M.

    1986-01-01

    Cygnus X-3 and some apparently related systems have sprung into remarkable prominence. The reasons for this great interest are summarized. Some recent developments in the picture of these sources are also outlined.

  19. 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.

  20. 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.

  1. Gamma-ray puzzle in Cygnus X: Implications for high-energy neutrinos

    NASA Astrophysics Data System (ADS)

    Yoast-Hull, Tova M.; Gallagher, John S.; Halzen, Francis; Kheirandish, Ali; Zweibel, Ellen G.

    2017-08-01

    The Cygnus X region contains giant molecular cloud complexes and populous associates of massive young stars. The discovery of spatially extended, hard γ -ray emission in Cygnus X by both Milagro and Fermi indicates that Cygnus X is also a potential source of high-energy Galactic neutrinos. Here, we adapt our single-zone model for cosmic ray interactions in the central molecular zones of starburst galaxies for use in Cygnus X. We calculate the potential neutrino flux corresponding to the hard γ -ray emission from the "Cygnus Cocoon" and to the soft, diffuse interstellar γ -ray emission. We check our results by comparing the corresponding γ -ray emission against the Fermi interstellar emission model and Milagro, ARGO-YBJ, and HAWC observations. In comparing our results against a recent IceCube analysis and the current sensitivity limits, we find that neutrino emission from the Cocoon has a large enough flux that it could plausibly be detected, provided hadronic interactions are occurring at sufficiently high energies. High-energy neutrinos from Cygnus X would provide direct evidence for the presence of as yet unidentified PeV energy accelerators in the Galactic disk.

  2. Space X1 First Entry Sample

    NASA Technical Reports Server (NTRS)

    James, John T.

    2012-01-01

    One mini-grab sample container (m-GSC) was returned aboard Space X1 because of the importance of quickly knowing first-entry conditions in this new commercial module. This sample was analyzed alongside samples of the portable clean room (PCR) used in the Space X complex at KSC. The recoveries of C-13-acetone, fluorobenzene, and chlorobenzene from the GSCs averaged 130, 129, and 132 %, respectively.

  3. Moving relativistic large-scale X-ray jets in the microquasar XTE J1550-564

    NASA Astrophysics Data System (ADS)

    Corbel, S.; Fender, R. P.; Tzioumis, A. K.; Tomsick, J. A.; Orosz, J. A.; Miller, J. M.; Wijnands, R.; Kaaret, P.

    2003-10-01

    We have discovered large-scale moving X-ray and radio jets from the microquasar XTE J1550-564. Using X-ray and radio observations performed between 2000 and 2002, we showed that plasma ejected from XTE J1550-564 has been able to travel at relativistic velocities during many years, with evidence for gradual deceleration. The broadband spectrum of the jets is consistent with synchrotron emission from high energy particles accelerated in shocks. Full details can be found in Corbel et al. [Science 298 (2002a) 196], Karret et al. [ApJ 582 (2003) 933] and Tomsick et al. [ApJ (2003) 945].

  4. Moving relativistic large-scale X-ray jets in the microquasar XTE J1550-564

    NASA Astrophysics Data System (ADS)

    Corbel, S.; Fender, R. P.; Tzioumis, A. K.; Tomsick, J. A.; Orosz, J. A.; Miller, J. M.; Wijnands, R.; Kaaret, P.

    We have discovered large-scale moving X-ray and radio jets from the microquasar XTE J1550-564. Using X-ray observations from the Chandra Observatory performed between June 2000 (see also Tomsick et al., these proceedings) and June 2002, we showed that ejected plasma from XTE J1550-564 has been able to travel at relativistic velocities during many years, with evidence for gradual deceleration. The broadband spectrum of the jets is consistent with synchrotron emission from high energy particles accelerated in shocks. Full details can be found in Corbel et al. 2002, Kaaret et al. 2002, Tomsick et al. 2002.

  5. Revisiting the dynamical case for a massive black hole in IC10 X-1

    NASA Astrophysics Data System (ADS)

    Laycock, Silas G. T.; Maccarone, Thomas J.; Christodoulou, Dimitris M.

    2015-09-01

    The relative phasing of the X-ray eclipse ephemeris and optical radial velocity (RV) curve for the X-ray binary IC10 X-1 suggests that the He [λ4686] emission line originates in a shadowed sector of the stellar wind that avoids ionization by X-rays from the compact object. The line attains maximum blueshift when the wind is directly towards us at mid X-ray eclipse, as is also seen in Cygnus X-3. If the RV curve is unrelated to stellar motion, evidence for a massive black hole (BH) evaporates because the mass function of the binary is unknown. The reported X-ray luminosity, spectrum, slow QPO and broad eclipses caused by absorption/scattering in the Wolf-Rayet (WR) wind are all consistent with either a low-stellar-mass BH or a neutron star (NS). For an NS, the centre of mass lies inside the WR envelope whose motion is then far below the observed 370 km s-1 RV amplitude, while the velocity of the compact object is as high as 600 km s-1. The resulting 0.4 per cent Doppler variation of X-ray spectral lines could be confirmed by missions in development. These arguments also apply to other putative BH binaries whose RV and eclipse curves are not yet phase-connected. Theories of BH formation and predicted rates of gravitational wave sources may need revision.

  6. 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.

  7. Subaru Spectroscopy and Spectral Modeling of Cygnus A

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

  8. 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.

  9. An infrared supershell surrounding the Cygnus OB1 association

    NASA Astrophysics Data System (ADS)

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

    1992-10-01

    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.

  10. Radial distribution of Fe XIV emission in the Cygnus Loop

    NASA Technical Reports Server (NTRS)

    Woodgate, B. E.; Kirshner, R. P.; Balon, R. J.

    1977-01-01

    The one dimensional distribution of Fe 14 emission has been determined along a radius of the Cygnus Loop through the use of a tilting filter photometer. The observed emission extends at least 5 arc minutes outside the optical filaments. A simple Sedov solution model of the temperature and density distribution behind the shock agrees with the observations if the shock front is near the extent of the Fe 14 emission, the shock velocity is from 300 to 250/kms and the density external to the remnant is about 0.7-1.4 cm to three minus 3 power. These parameters are in reasonable agreement with X-ray maps and optical radial velocities.

  11. 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.

  12. An infrared supershell surrounding the Cygnus OB1 association

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  13. Soft X-rays from the Cygnus Loop: Interpretation.

    PubMed

    Tucker, W H

    1971-04-23

    Two possible interpretations of the recent soft x-ray observation of the Cygnus Loop are discussed. A synchrotron model requires a magnetic field less than 10(-6) gauss and electron energies in excess of 10(14) electron volts. These electrons must either have been reaccelerated or continuously injected into the source for about 50,000 years. The observations are also consistent with the radiation from a hot plasma having the cosmic abundances of the elements. A likely origin for the hot plasma is a blast wave produced by the explosion of a supernova in the interstellar medium. Fitting such a model to the observations implies a kinetic energy release in the explosion of 6x 10(50) ergs for an assumed distance of 770 parsec.

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

    USGS Publications Warehouse

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

    2002-01-01

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

  15. 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.

  16. Cygnus OB2 - Archaeology Of Our Closest Massive Star Factory

    NASA Astrophysics Data System (ADS)

    Van Der Veen, Erik

    2011-01-01

    Cygnus OB2 is the nearest example of a massive star-forming region, at only 1.45kpc. Despite its status and importance, we still lack a basic understanding of this complex. Practically all of its 50+ O-type stars and some of its B-type stars have been scoped, but low-mass members remain poorly studied. An extensive set of new spectra collected using the FAST and HectoSpec instruments at the Fred Lawrence Whipple Observatory is allowing for a much more detailed study of the association. Optical spectra of pre-main sequence objects, vital in developing our global understanding of star formation and the products thereof, are being analyzed in order to characterize masses and velocities of individual objects within the region. The level of reddening of the spectra is first identified, providing a more reliable estimate of spectral type than photometry alone, and from which stellar mass and temperatures are derived. Velocities are then obtained via cross-correlation and line centroiding techniques. Combining these two results will map out the distribution of velocities as a function of stellar mass. The end goal of this study is to understand the dynamics and boundedness of the cluster, and to diagnose the presence of any sub-clustering and mass segregation. In this way, Cygnus OB2 is poised to become a stepping stone with which to extend our detailed understanding of Gould Belt star forming regions down to the lowest mass stars to much more massive clusters and starbursts.

  17. BLACK HOLE MASS AND SPIN FROM THE 2:3 TWIN-PEAK QPOs IN MICROQUASARS

    SciTech Connect

    Mondal, Soumen

    2010-01-10

    In the Galactic microquasars with double peak kHz quasi-periodic oscillations (QPOs) detected in X-ray fluxes, the ratio of the twin-peak frequencies is exactly, or almost exactly 2:3. This rather strongly supports the fact that they originate a few gravitational radii away from its center due to two modes of accretion disk oscillations. Numerical investigations suggest that post-shock matter, before they settle down in a subsonic branch, execute oscillations in the neighborhood region of 'shock transition'. This shock may excite QPO mechanism. The radial and vertical epicyclic modes of oscillating matter exactly match with these twin-peak QPOs. In fully general relativistic transonic flows, we investigate that shocks may form very close to the horizon around highly spinning Kerr black holes and appear as extremum in the inviscid flows. The extreme shock location provides upper limit of QPOs and hence fixes 'lower cutoff' of the spin. We conclude that the 2:3 ratio exactly occurs for spin parameters a >= 0.87 and almost exactly, for wide range of spin parameter, for example, XTE 1550-564, and GRO 1655-40 a>0.87, GRS 1915+105 a>0.83, XTE J1650-500 a>0.78, and H 1743-322 a>0.68. We also make an effort to measure unknown mass for XTE J1650-500(9.1 approx 14.1 M{sub sun}) and H 1743-322(6.6 approx 11.3 M{sub sun}).

  18. Black Hole Mass and Spin from the 2:3 Twin-peak QPOs in Microquasars

    NASA Astrophysics Data System (ADS)

    Mondal, Soumen

    2010-01-01

    In the Galactic microquasars with double peak kHz quasi-periodic oscillations (QPOs) detected in X-ray fluxes, the ratio of the twin-peak frequencies is exactly, or almost exactly 2:3. This rather strongly supports the fact that they originate a few gravitational radii away from its center due to two modes of accretion disk oscillations. Numerical investigations suggest that post-shock matter, before they settle down in a subsonic branch, execute oscillations in the neighborhood region of "shock transition". This shock may excite QPO mechanism. The radial and vertical epicyclic modes of oscillating matter exactly match with these twin-peak QPOs. In fully general relativistic transonic flows, we investigate that shocks may form very close to the horizon around highly spinning Kerr black holes and appear as extremum in the inviscid flows. The extreme shock location provides upper limit of QPOs and hence fixes "lower cutoff" of the spin. We conclude that the 2:3 ratio exactly occurs for spin parameters a >= 0.87 and almost exactly, for wide range of spin parameter, for example, XTE 1550-564, and GRO 1655-40 a>0.87, GRS 1915+105 a>0.83, XTE J1650-500 a>0.78, and H 1743-322 a>0.68. We also make an effort to measure unknown mass for XTE J1650-500(9.1 ~ 14.1 M sun) and H 1743-322(6.6 ~ 11.3 M sun).

  19. Accretion-ejection morphology of the microquasar SS 433 resolved at sub-au scale

    NASA Astrophysics Data System (ADS)

    Gravity Collaboration; Petrucci, P.-O.; Waisberg, I.; Le Bouquin, J.-B.; Dexter, J.; Dubus, G.; Perraut, K.; Kervella, P.; Abuter, R.; Amorim, A.; Anugu, N.; Berger, J. P.; Blind, N.; Bonnet, H.; Brandner, W.; Buron, A.; Choquet, É.; Clénet, Y.; de Wit, W.; Deen, C.; Eckart, A.; Eisenhauer, F.; Finger, G.; Garcia, P.; Garcia Lopez, R.; Gendron, E.; Genzel, R.; Gillessen, S.; Gonte, F.; Haubois, X.; Haug, M.; Haussmann, F.; Henning, Th.; Hippler, S.; Horrobin, M.; Hubert, Z.; Jochum, L.; Jocou, L.; Kok, Y.; Kolb, J.; Kulas, M.; Lacour, S.; Lazareff, B.; Lèna, P.; Lippa, M.; Mérand, A.; Müller, E.; Ott, T.; Panduro, J.; Paumard, T.; Perrin, G.; Pfuhl, O.; Ramos, J.; Rau, C.; Rohloff, R.-R.; Rousset, G.; Sanchez-Bermudez, J.; Scheithauer, S.; Schöller, M.; Straubmeier, C.; Sturm, E.; Vincent, F.; Wank, I.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Wittkowski, M.; Woillez, J.; Yazici, S.; Zins, G.

    2017-06-01

    We present the first optical observation of the microquasar SS 433 at sub-milliarcsecond (mas) scale obtained with the GRAVITY instrument on the Very Large Telescope interferometer (VLTI). The 3.5-h exposure reveals a rich K-band spectrum dominated by hydrogen Brγand He I lines, as well as (red-shifted)emission lines coming from the jets. The K-band-continuum-emitting region is dominated by a marginally resolved point source (<1 mas) embedded inside a diffuse background accounting for 10% of the total flux. The jet line positions agree well with the ones expected from the jet kinematic model, an interpretation also supported by the consistent sign (i.e., negative/positive for the receding/approaching jet component) of the phase shifts observed in the lines. The significant visibility drop across the jet lines, together with the small and nearly identical phases for all baselines, point toward a jet that is offset by less than 0.5 mas from the continuum source and resolved in the direction of propagation, with a typical size of 2 mas. The jet position angle of 80° is consistent with the expected one at the observation date. Jet emission so close to the central binary system would suggest that line locking, if relevant to explain the amplitude and stability of the 0.26c jet velocity, operates on elements heavier than hydrogen. The Brγprofile is broad and double peaked. It is better resolved than the continuum and the change of the phase signal sign across the line on all baselines suggests an East-West-oriented geometry similar to the jet direction and supporting a (polar) disk wind origin. Based on observations made with VLTI/Gravity instrument.

  20. Optical spectroscopy of the microquasar GRS 1758-258: a possible intermediate mass system?

    NASA Astrophysics Data System (ADS)

    Martí, Josep; Luque-Escamilla, Pedro L.; Muñoz-Arjonilla, Álvaro J.

    2016-11-01

    Context. GRS 1758-258 is one of two prototypical microquasars towards the Galactic center direction discovered almost a quarter of a century ago. The system remains poorly studied in the optical domain due to its counterpart being a very faint and absorbed target in a crowded region of the sky. Aims: Our aim is to investigate GRS 1758-258 in order to shed light on the nature of the stellar binary components. In particular, the main physical parameters of the donor star, such as the mass or the spectral type, are not yet well constrained. Methods: GRS 1758-258 has remained so far elusive to optical spectroscopy owing to its observational difficulties. Here, we use this traditional tool of stellar astronomy at low spectral resolution with a 10 m class telescope and a long slit spectrograph. Results: An improved spectrum is obtained as compared to previous work. The quality of the data does not allow the detection of emission or absorption features but, nevertheless, we manage to partially achieve our aims comparing the de-reddened continuum with the spectral energy distribution expected from an irradiated disc model and different donor star templates. Conclusions: We tentatively propose that GRS 1758-258 does not host a giant star companion. Instead, a main sequence star with mid-A spectral type appears to better agree with our data. The main impacts of this finding are the possibility that we are dealing with an intermediate mass system and, in this case, the prediction of an orbital period significantly shorter than previously proposed.

  1. A Resonantly Excited Disk-Oscillation Model of High-Frequency QPOs of Microquasars

    NASA Astrophysics Data System (ADS)

    Kato, Shoji

    2012-12-01

    A possible model of twin high-frequency QPOs (HF QPOs) of microquasars is examined. The disk is assumed to have global magnetic fields and to be deformed with a two-armed pattern. In this deformed disk, a set of a two-armed (m = 2) vertical p-mode oscillation and an axisymmetric (m = 0) g-mode oscillation is considered. They resonantly interact through the disk deformation when their frequencies are the same. This resonant interaction amplifies the set of the above oscillations in the case where these two oscillations have wave energies of opposite signs. These oscillations are assumed to be excited most efficiently in the case where the radial group velocities of these two waves vanish at the same place. The above set of oscillations is not unique, depending on the node number n, of oscillations in the vertical direction. We consider that the basic two sets of oscillations correspond to the twin QPOs. The frequencies of these oscillations depend on the disk parameters, such as the strength of the magnetic fields. For observational mass ranges of GRS 1915+ 105, GRO J1655-40, XTE J1550-564, and HEAO H1743-322, the spins of these sources are estimated. High spins of these sources can be described if the disks have weak poloidal magnetic fields as well as toroidal magnetic fields of moderate strength. In this model the 3:2 frequency ratio of high-frequency QPOs is not related to their excitation, but occurs by chance.

  2. Trace element exposure of whooper swans (Cygnus cygnus) wintering in a marine lagoon (Swan Lake), northern China.

    PubMed

    Wang, Feng; Xu, Shaochun; Zhou, Yi; Wang, Pengmei; Zhang, Xiaomei

    2017-06-30

    Trace element poisoning remains a great threat to various waterfowl and waterbirds throughout the world. In this study, we determined the trace element exposure of herbivorous whooper swans (Cygnus cygnus) wintering in Swan Lake (Rongcheng), an important swan protection area in northern China. A total of 70 samples including abiotic factors (seawater, sediments), food sources (seagrass, macroalgae), feathers and feces of whooper swans were collected from the marine lagoon during the winters of 2014/2015 and 2015/2016. Concentrations of Cu, Zn, Pb, Cr, Cd, Hg and As were determined to investigate the trace element exposure of whooper swans wintering in the area. Results showed that there was an increasing trend in sediment trace element concentrations, compared with historical data. The trace element concentrations in swan feces most closely resembled those of Zostera marina leaves, especially for Cd and Cr. The Zn and Hg concentrations in the swan feces (49.57 and 0.01mg/kg, respectively) were lower than the minimum values reported in the literature for other waterfowls, waterbirds and terrestrial birds. However, the concentrations of the other five trace elements fell within the lower and mediate range of values reported for birds across the world. These results suggest that the whooper swans wintering in Swan Lake, Rongcheng are not suffering severe trace element exposure; however, with the increasing input of trace elements to the lagoon, severe adverse impacts may occur in the future, and we therefore suggest that the input of trace elements to this area should be curbed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Pulse Shape Evolution, HER X-1

    NASA Technical Reports Server (NTRS)

    VanParadijs, Johannes A.

    1998-01-01

    This study focuses on the pulse shape evolution and spectral properties of the X-ray binary Her X-1 with regard to the well known 35-day cycle of Her X-1. A follow-up set of RXTE observations has been conducted in RXTE AO-2 phase and the two observation sets are being analyzed together. We presented results of early analysis of pulse shape evolution in "Proceedings of the Fourth Compton Symposium." More advanced analysis was presented at the HEAD meeting in November, 1997 in Estes Park, Colorado. A related study of the 35-day cycle using RXTE/ASM data, which laid out the overall picture within which the more detailed PCA observations could be placed has also been conducted. The results of this study have been published in The Astrophysical Journal, vol. 510, 974. A pair of papers on the detailed pulse evolution and the spectral/color evolution are currently being prepared for publication. Some of the significant results of this study have been a confirmation of the detailed pulse profile changes at the end of the Main High state in Her X-1 first observed by GINGA, observations of the pulse evolution in several Short High states which agree with the pulse evolution pattern predicted using a disk occultation model in the PhD Thesis of Scott 1993, observation of a systematic lengthening of the eclipse egress during the Main High state of the 35-day phase and observation of a new type of extended eclipse ingress during which pulsations cease to observed during the Short High state.

  4. ORNL Cray X1 evaluation status report

    SciTech Connect

    Agarwal, P.K.; Alexander, R.A.; Apra, E.; Balay, S.; Bland, A.S; Colgan, J.; D'Azevedo, E.F.; Dongarra, J.J.; Dunigan Jr., T.H.; Fahey, M.R.; Fahey, R.A.; Geist, A.; Gordon, M.; Harrison, R.J.; Kaushik, D.; Krishnakumar, M.; Luszczek, P.; Mezzacappa, A.; Nichols, J.A.; Nieplocha, J.; Oliker, L.; Packwood, T.; Pindzola, M.S.; Schulthess, T.C.; Vetter, J.S.; White III, J.B.; Windus, T.L.; Worley, P.H.; Zacharia, T.

    2004-05-01

    On August 15, 2002 the Department of Energy (DOE) selected the Center for Computational Sciences (CCS) at Oak Ridge National Laboratory (ORNL) to deploy a new scalable vector supercomputer architecture for solving important scientific problems in climate, fusion, biology, nanoscale materials and astrophysics. ''This program is one of the first steps in an initiative designed to provide U.S. scientists with the computational power that is essential to 21st century scientific leadership,'' said Dr. Raymond L. Orbach, director of the department's Office of Science. In FY03, CCS procured a 256-processor Cray X1 to evaluate the processors, memory subsystem, scalability of the architecture, software environment and to predict the expected sustained performance on key DOE applications codes. The results of the micro-benchmarks and kernel bench marks show the architecture of the Cray X1 to be exceptionally fast for most operations. The best results are shown on large problems, where it is not possible to fit the entire problem into the cache of the processors. These large problems are exactly the types of problems that are important for the DOE and ultra-scale simulation. Application performance is found to be markedly improved by this architecture: - Large-scale simulations of high-temperature superconductors run 25 times faster than on an IBM Power4 cluster using the same number of processors. - Best performance of the parallel ocean program (POP v1.4.3) is 50 percent higher than on Japan s Earth Simulator and 5 times higher than on an IBM Power4 cluster. - A fusion application, global GYRO transport, was found to be 16 times faster on the X1 than on an IBM Power3. The increased performance allowed simulations to fully resolve questions raised by a prior study. - The transport kernel in the AGILE-BOLTZTRAN astrophysics code runs 15 times faster than on an IBM Power4 cluster using the same number of processors. - Molecular dynamics simulations related to the phenomenon of

  5. Testing modified gravity and no-hair relations for the Kerr-Newman metric through quasiperiodic oscillations of galactic microquasars

    NASA Astrophysics Data System (ADS)

    Suvorov, Arthur George; Melatos, Andrew

    2016-01-01

    We construct multipole moments for stationary, asymptotically flat, spacetime solutions to higher-order curvature theories of gravity. The moments are defined using 3 +1 techniques involving timelike Killing vector constructions as in the classic papers by Geroch and Hansen. Using the fact that the Kerr-Newman metric is a vacuum solution to a particular class of f (R ) theories of gravity, we compute all its moments, and find that they admit recurrence relations similar to those for the Kerr solution in general relativity. It has been proposed previously that modeling the measured frequencies of quasiperiodic oscillations from galactic microquasars enables experimental tests of the no-hair theorem. We explore the possibility that, even if the no-hair relation is found to break down in the context of general relativity, there may be an f (R ) counterpart that is preserved. We apply the results to the microquasars GRS 1915 +105 and GRO J1655-40 using the diskoseismology and kinematic resonance models, and constrain the spins and "charges" of their black holes.

  6. High energy gamma rays from nebulae associated with extragalactic microquasars and ultra-luminous X-ray sources

    NASA Astrophysics Data System (ADS)

    Inoue, Yoshiyuki; Lee, Shiu-Hang; Tanaka, Yasuyuki T.; Kobayashi, Shogo B.

    2017-04-01

    In the extragalactic sky, microquasars and ultra-luminous X-ray sources (ULXs) are known as energetic compact objects locating at off-nucleus positions in galaxies. Some of these objects are associated with expanding bubbles with a velocity of 80-250 km s - 1. We investigate the shock acceleration of particles in those expanding nebulae. The nebulae having fast expansion velocity ≳ 120km s - 1 are able to accelerate cosmic rays up to ∼100 TeV. If 10% of the shock kinetic energy goes into particle acceleration, powerful nebulae such as the microquasar S26 in NGC 7793 would emit gamma rays up to several tens TeV with a photon index of ∼2. These nebulae will be good targets for future Cherenkov Telescope Array observations given its sensitivity and angular resolution. They would also contribute to ∼7% of the unresolved cosmic gamma-ray background radiation at ≥ 0.1 GeV. In contrast, particle acceleration in slowly expanding nebulae ≲ 120km s - 1 would be less efficient due to ion-neutral collisions and result in softer spectra at ≳ 10 GeV.

  7. A 300-parsec-long jet-inflated bubble around a powerful microquasar in the galaxy NGC 7793.

    PubMed

    Pakull, Manfred W; Soria, Roberto; Motch, Christian

    2010-07-08

    Black-hole accretion states near or above the Eddington luminosity (the point at which radiation force outwards overcomes gravity) are still poorly known because of the rarity of such sources. Ultraluminous X-ray sources are the most luminous class of black hole (L(X) approximately 10(40) erg s(-1)) located outside the nuclei of active galaxies. They are likely to be accreting at super-Eddington rates, if they are powered by black holes with masses less than 100 solar masses. They are often associated with shock-ionized nebulae, though with no evidence of collimated jets. Microquasars with steady jets are much less luminous. Here we report that the large nebula S26 (ref. 4) in the nearby galaxy NGC 7793 is powered by a black hole with a pair of collimated jets. It is similar to the famous Galactic source SS433 (ref. 5), but twice as large and a few times more powerful. We determine a mechanical power of around a few 10(40) erg s(-1). The jets therefore seem 10(4) times more energetic than the X-ray emission from the core. S26 has the structure of a Fanaroff-Riley type II (FRII-type) active galaxy: X-ray and optical core, X-ray hot spots, radio lobes and an optical and X-ray cocoon. It is a microquasar where most of the jet power is dissipated in thermal particles in the lobes rather than relativistic electrons.

  8. Jet power and feedback from the newly-discovered radio/optical/X-ray microquasar S26 in NGC 7793

    NASA Astrophysics Data System (ADS)

    Soria, Roberto; Corbel, Stephane; Pakull, Manfred; Motch, Christian

    2009-07-01

    We have discovered an exceptional radio/optical/X-ray microquasar in the Sculptor galaxy NGC7793 (distance of 3.4 Mpc), with a large (300 x 150 pc) shock-ionized bubble, and X-ray hot spots where the collimated jet hits the interstellar medium. The radio nebula has an integrated flux of 1.2 mJy at 6 cm (more luminous than Cas A). The system resembles the famous Galactic microquasar SS433, but on an even grander scale. We propose deeper radio observations at higher spatial resolution with the ATCA: to identify the radio hot spots; to infer the jet power from the synchrotron luminosity of the hot spots; to determine the shape of the radio cocoon and compare it with the H-alpha, HeII 4686 and X-ray nebulae; to estimate the total (integrated) energy injected in the nebula by the jet/wind, and constrain its age; to search for the radio core. Our combined radio, X-ray and optical study of this source will help us model the radiative and mechanical power budget of accreting black holes, and their feedback onto the interstellar or intergalactic medium.

  9. X1X1X2X2/X1X2Y sex chromosome systems in the Neotropical Gymnotiformes electric fish of the genus Brachyhypopomus

    PubMed Central

    Cardoso, Adauto Lima; Pieczarka, Julio Cesar; Nagamachi, Cleusa Yoshiko

    2015-01-01

    Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The X1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gauderio presented this type of system. Herein we describe the karyotypes of Brachyhypopomus pinnicaudatus and B. n. sp. FLAV, which have an X1X1X2X2/X1X2Y sex chromosome system that evolved via fusion between an autosome and the Y chromosome. The morphology of the chromosomes and the meiotic pairing suggest that the sex chromosomes of B. gauderio and B. pinnicaudatus have a common origin, whereas in B . n. sp. FLAV the sex chromosome system evolved independently. However, we cannot discard the possibility of common origin followed by distinct processes of differentiation. The identification of two new karyotypes with an X1X1X2X2/X1X2Y sex chromosome system in Gymnotiformes makes it the most common among the karyotyped species of the group. Comparisons of these karyotypes and the evolutionary history of the taxa indicate independent origins for their sex chromosomes systems. The recurrent emergence of the X1X1X2X2/X1X2Y system may represent sex chromosomes turnover events in Gymnotiformes. PMID:26273225

  10. Evidence for a TDE Origin for the Radio Transient in Cygnus A

    NASA Astrophysics Data System (ADS)

    Wise, Michael W.; de Vries, Martijn; Rowlinson, Antonia; Nulsen, Paul; Snios, Bradford; Birkinshaw, Mark; Worrall, Diana

    2017-08-01

    Recently new JVLA observations by Perley et al. (2017) have revealed evidence for a luminous radio transient at a projected distance of 0.46 kpc from the nucleus of Cygnus A. Based on data taken between 1989 and 2016, the flux density of this radio transient has risen from an upper limit of <0.5 mJy to 4 mJy at a frequency of 8.5 GHz. Additional VLBA observations at 8 GHz by the same authors confirm this transient source to be compact (<4 pc) and coinciding with a source seen previously in optical and NIR images. Perley et al. (2017) have interpreted this source to be a secondary supermassive black hole in a close orbit around the Cygnus A nucleus. Several explanations have been proposed for the turn-on of the Cygnus A-2 transient over the 9 year timeframe including variability in the accretion onto this secondary BH and alternatively a possible tidal disruption event (TDE).We present the results of a new X-ray analysis utilizing new and archival data from the Chandra and Swift satellites. Cygnus A has been observed multiple times by Chandra between 2000, 2005, and 2015-2017. The Swift satellite performed 9 observations of Cygnus A between 2006 and 2017. Based on these observations, we present evidence for a decline in the flux of the Cygnus A nucleus, with the soft X-ray flux (0.3-1.2 keV) showing a drop by a factor of 2 between 2000 and 2005. The Swift observations confirm the X-ray emission from the Cygnus A continued to fade after 2006. As the radio source was last undetected in 1997, these data constrain the peak of the X-ray emission and the likely onset of brightening in the radio to a window of 3 years or less. This timescale implies a very rapid onset of accretion onto the secondary black hole and strongly favors the TDE interpretation for the origin of the Cygnus A-2 radio transient. Chandra images of the 3 kpc x 3 kpc region around the Cygnus A nucleus show clear evidence for an extended region of soft X-ray emission dimming on this timescale, which we

  11. Radio lobes and X-ray hotspots in the microquasar S26

    NASA Astrophysics Data System (ADS)

    Soria, Roberto; Pakull, Manfred W.; Broderick, Jess W.; Corbel, Stephane; Motch, Christian

    2010-12-01

    We have studied the structure and energetics of the powerful microquasar/shock-ionized nebula S26 in NGC7793, with particular focus on its radio and X-ray properties. Using the Australia Telescope Compact Array, we have resolved for the first time the radio lobe structure and mapped the spectral index of the radio cocoon. The steep spectral index of the radio lobes is consistent with optically-thin synchrotron emission; outside the lobes, the spectral index is flatter, suggesting an additional contribution from free-free emission, and perhaps ongoing ejections near the core. The radio core is not detected, while the X-ray core has a 0.3-8 keV luminosity ~6 × 1036 erg s-1. The size of the radio cocoon matches that seen in the optical emission lines and diffuse soft X-ray emission. The total 5.5-GHz flux of cocoon and lobes is ~2.1 mJy, which at the assumed distance of 3.9 Mpc corresponds to about three times the luminosity of Cas A. The total 9.0-GHz flux is ~1.6 mJy. The X-ray hotspots (combined 0.3-8 keV luminosity ~2 × 1037 erg s-1) are located ~20 pc outwards of the radio hotspots (i.e. downstream along the jet direction), consistent with a different physical origin of X-ray and radio emission (thermal-plasma and synchrotron, respectively). The total particle energy in the bubble is ~1053 erg: from the observed radio flux, we estimate that only approximately a few times 1050 erg is stored in the relativistic electrons; the rest is stored in protons, nuclei and non-relativistic electrons. The X-ray-emitting component of the gas in the hotspots contains ~1051 erg, and ~1052 erg over the whole cocoon. We suggest that S26 provides a clue to understand how the ambient medium is heated by the mechanical power of a black hole near its Eddington accretion rate.

  12. Leon X-1, the First Chandra Source

    NASA Technical Reports Server (NTRS)

    Weisskopf, Martin C.; Aldcroft, Tom; Cameron, Robert A.; Gandhi, Poshak; Foellmi, Cedric; Elsner, Ronald F.; Patel, Sandeep K.; ODell, Stephen L.

    2004-01-01

    Here we present an analysis of the first photons detected with the Chandra X-ray Observatory and an identification of the brightest source in the field which we named Leon X-1 to honor the momentous contributions of the Chandra Telescope Scientist, Leon Van Speybroeck. The observation took place immediately following the opening of the last door protecting the X-ray telescope. We discuss the unusual operational conditions as the first extra-terrestrial X-ray photons reflected from the telescope onto the ACIS camera. One bright source was a p parent to the team at the control center and the small collection of photons that appeared on the monitor were sufficient to indicate that the telescope had survived the launch and was approximately in focus, even prior to any checks and subsequent adjustments.

  13. Cyg X-1 - A massive neutron star

    NASA Technical Reports Server (NTRS)

    Goldman, I.

    1981-01-01

    The expected X-ray emission from Cyg X-1, considered a massive neutron star (8-15 solar masses) according to some gravity theories, is studied within the framework of Rosen's bimetric gravity theory (1973, 1974). It is shown that in such massive neutron stars, the innermost stable orbit lies far outside the star surface, and therefore the X-ray spectrum consists of two components: a soft one emitted from a cold accretion disk and a hard one emitted by the matter striking the neutron star surface after spiraling down freely from the disk. The proposed model is shown to be in good agreement with the observed luminosities. The model predicts a surface gravitational redshift of 3.16 which could be tested by the future X- and gamma-ray detectors.

  14. THE ORBITAL PERIOD OF SCORPIUS X-1

    SciTech Connect

    Hynes, Robert I.; Britt, Christopher T.

    2012-08-10

    The orbital period of Sco X-1 was first identified by Gottlieb et al. While this has been confirmed on multiple occasions, this work, based on nearly a century of photographic data, has remained the reference in defining the system ephemeris ever since. It was, however, called into question when Vanderlinde et al. claimed to find the one-year alias of the historical period in RXTE/All-Sky Monitor data and suggested that this was the true period rather than that of Gottlieb et al. We examine data from the All Sky Automated Survey (ASAS) spanning 2001-2009. We confirm that the period of Gottlieb et al. is in fact the correct one, at least in the optical, with the one-year alias strongly rejected by these data. We also provide a modern time of minimum light based on the ASAS data.

  15. Serendipitous Discovery of a Radio Transient in the Luminous Radio Galaxy Cygnus A

    NASA Astrophysics Data System (ADS)

    Perley, Richard A.; Perley, Daniel A.; Carilli, Chris Luke; Dhawan, Vivek

    2017-01-01

    Recent Jansky Very Large Array observations of the luminous radio galaxy Cygnus A have revealed the presence of a 3 mJy, flat-spectrum, unresolved radio source located 0.4" (450 pc) from the nucleus. This source was not present in observations made 25 years ago. The luminosity and SED of the transient are comparable to the most luminous supernovae in the universe, and to GRB afterglows, although the most likely interpretation is that the transient represents a luminous flare from the nucleus of a minor galaxy merging with the host of Cygnus A -- possibly in the form of a tidal disruption event. We present our observations and interpretation of this event using recent JVLA and VLBA observations, and discuss its implications for the Cygnus A system and for dusty, merging galaxies generally.

  16. 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.

  17. OA-7 CYGNUS Unbagging, Move from Airlock to Highbay, Lift to Stand at PHSF

    NASA Image and Video Library

    2017-02-24

    Inside the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, technicians remove the protective covering from Orbital ATK's CYGNUS pressurized cargo module on a KAMAG transporter. CYGNUS is then moved from the airlock to the highbay inside the PHSF, followed by the payload being lifted and positioned on a work stand for final propellant loading and late cargo stowage. The Orbital ATK CRS-7 commercial resupply services mission to the International Space Station is scheduled to launch atop a United Launch Alliance Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station on March 19, 2017. CYGNUS will deliver thousands of pounds of supplies, equipment and scientific research materials to the space station.

  18. Bayesian SED Fitting of YSOs in Cygnus-X

    NASA Astrophysics Data System (ADS)

    Martinez-Galarza, Rafael; Hora, Joseph; Azimlu, Mohaddesseh; Smith, Howard

    2013-07-01

    We present a Montecarlo Bayesian tool to fit the spectral energy distributions (SEDs) of young stellar objects (YSOs), based on the Robitaille et al. 2006 grid of YSO SED models. Given a set of observations, the method computes the probability distribution functions (PDFs) for the model parameters and illustrate model degeneracies that should be taken into account in the interpretation of the results. We use the tool to fit the optical to mid-infrared SEDs of a collection of ˜800 intermediate-mass YSOs in the Cygnus-X star-forming region and derive posterior PDFs for physical parameters of the sample, such as YSO mass, age and external extinction. Our derived values for age and extinction values agree with independent measurements. We find that the present degeneracies (such as the mass-age degeneracy) can jeopardize some of the parameters derived with SED fitting, specially for Class IIa YSOs, where we find a significant under-estimation of the YSO mass. The method is automated and can be used with any set of YSO photometry.

  19. 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.

  20. Resolving the Cygnus X-3 iron K line

    NASA Technical Reports Server (NTRS)

    Kitamoto, Shunji; Kawashima, Kenji; Negoro, Hitoshi; Miyamoto, Sigenori; White, N. E.; Nagase, Fumiaki

    1994-01-01

    An Advanced Satellite for Cosmology and Astrophysics (ASCA) observation of Cygnus X-3 on 1993 June 11, in its X-ray high intensity state, has for the first time resolved the broad iron K line emission into three components: a He-like line at 6.67 +/- 0.01 keV, a H-like line at 6.96 +/- 0.02 keV, and a neutral line at 6.37 +/- 0.03 keV. The line intensities of the 6.67 keV and 6.96 keV lines are modulated with the 4.8 hr orbital period and are maximum when the continuum intensity is minimum. There is a sharp minimum of the line intensity on the rising phase of the continuum intensity. An iron absorption edge is observed at 7.19 +/- 0.02 keV. The optical depth of the absorption edge varies from 0.3 to 0.5 and is in anti-phase with the overall X-ray continuum modulation. The observed complexity of the iron K line region is greater than that had been assumed in previous spectral modeling based on observations with lower resolution detectors.

  1. 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.

  2. Rapid X-ray Variability in Cygnus X-l

    NASA Astrophysics Data System (ADS)

    Axelsson, Magnus

    2008-09-01

    In this paper, results from temporal analysis of RXTE observations of the black hole binary Cygnus X-l are reviewed. By tapping into the large amount of archival data available, a systematic study of the variability, in the form of the power spectrum, is conducted. It is clear that timing studies can give valuable information on the emission mechanisms and accretion geometry. Tying characteristic frequencies to effects predicted by general relativity directly gives information about the parameters of the compact object. The results show that the characteristic frequencies seen in the power spectrum follow the relation predicted for the nodal and periastron precessional frequencies of relativistic precession. From this relation, the spin of the black hole is determined to a* = 0.48+/-0.01 for a mass of 9 Msolar. During times of high hardness, the hardness-flux correlation seen in the hard state of the source disappears on short timescales. Together with the variable characteristic frequencies, this is interpreted as support for the truncated disk scenario.

  3. Young Stars in the Cygnus OB2 Association

    NASA Astrophysics Data System (ADS)

    Hartigan, Patrick; Cleeves, Ilse

    2009-08-01

    Cygnus OB2 is by far the dominant region of massive star formation within 2-3 kpc of the Sun, but its stellar content is almost completely unknown owing to large amounts of visual extinction. Using NEWFIRM last fall we surveyed a large area of over two square degrees centered on the main cluster of O and B stars, and found the central part of the cluster to be teeming with at least several hundred, and probably over a thousand stars with near-IR excesses typical of circumstellar disks. With this proposal we aim to begin the process of acquiring spectral types for the entire sample of IR-excess and X-ray bright stars. This census will lead to masses, ages, and accretion rates for each object. With over 100 O stars, Cyg OB2 dwarfs the young clusters in Orion, and promises to provide a truly unique large sample of young stars that can address many of the major outstanding questions of star formation, such as IMF variations, binarity, triggering, mass segregation, accretion history, and disk evolution in a statistically significant way.

  4. "What's on Board" Science Briefing for Cygnus Orbital ATK OA-6

    NASA Image and Video Library

    2016-03-21

    Gary Ruff, NASA project manager and co-investigator for the Spacecraft Fire Safety Demonstration Project, or Saffire, at the Glenn Research Center in Cleveland, speaks to members of the media in the Kennedy Space Center’s Press Site auditorium. The briefing focused on science research and technology work planned for the International Space Station, or ISS, following the arrival of a Cygnus spacecraft. The Cygnus is scheduled to be launched March 22 atop a United Launch Alliance Atlas V rocket on the Orbital ATK CRS-6 commercial resupply services mission.

  5. Circumstellar Structure Around Evolved Stars in the Cygnus-X Star Formation Region

    DTIC Science & Technology

    2010-06-01

    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 ...evolved stars in the Cygnus-X star-forming region. One of the objects, BD+43 3710, has a bipolar nebula , possibly due to an outllow or a torus of...of evolved objects in the survey region, from Miras and Cepheids to Wolf-Rayet (WR) and carbon stars to planetary nebulae (PNe) and supernova

  6. 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.

  7. "What's on Board" Science Briefing for Cygnus Orbital ATK OA-6

    NASA Image and Video Library

    2016-03-21

    Dr. Aaron Parness, group leader at the Jet Propulsion Laboratory in Pasadena, California, who is working the Extreme Environment Robots Group on the Gecko Grippers experiment, speaks to members of the media in the Kennedy Space Center’s Press Site auditorium. The briefing focused on science research and technology work planned for the International Space Station, or ISS, following the arrival of a Cygnus spacecraft. The Cygnus is scheduled to be launched March 22 atop a United Launch Alliance Atlas V rocket on the Orbital ATK CRS-6 commercial resupply services mission.

  8. An opaque shell around Hercules X-1

    NASA Technical Reports Server (NTRS)

    Mccray, R.; Lamb, F. K.

    1976-01-01

    It is suggested that the observed soft X-rays from Her X-1 are the result of an opaque gas shell which surrounds the neutron star at a radius where centrifugal force and the magnetic field impede the gravitational infall of the gas and which absorbs a substantial fraction of the hard X-ray flux, reradiating it as soft X-rays. Two highly idealized models for the shell are constructed in which the radius and temperature are 7000 km and 550,000 K or 1300 km and 1.5 million K, respectively. These models are intended to show that a gas shell with interesting spectral characteristics is likely to occur at a radius of 2000 to 7000 km from the neutron star if the magnetic field impedes the gas infall at this radius and that such a shell is indicated by the soft X-ray observations. A possible geometry is considered wherein the shell is a wide opaque ring at the magnetic equator, becomes transparent at high latitudes, and becomes opaque again at the magnetic poles.

  9. [Gene therapy of SCID-X1].

    PubMed

    Baum, C; Schambach, A; Modlich, U; Thrasher, A

    2007-12-01

    X-linked severe combined immunodeficiency (SCID-X1) is an inherited disease caused by inactivating mutations in the gene encoding the interleukin 2 receptor common gamma chain (IL2RG), which is located on the X-chromosome. Affected boys fail to develop two major effector cell types of the immune system (T cells and NK cells) and suffer from a functional B cell defect. Although drugs such as antibiotics can offer partial protection, the boys normally die in the first year of life in the absence of a curative therapy. For a third of the children, bone marrow transplantation from a fully matched donor is available and can cure the disease without major side effects. Mismatched bone marrow transplantation, however, is complicated by severe and potentially lethal side effects. Over the past decade, scientists worldwide have developed new treatments by introducing a correct copy of the IL2RG-cDNA. Gene therapy was highly effective when applied in young children. However, in a few patients the IL2RG-gene vector has unfortunately caused leukaemia. Activation of cellular proto-oncogenes by accidental integration of the gene vector has been identified as the underlying mechanism. In future clinical trials, improved vector technology in combination with other protocol modifications may reduce the risk of this side effect.

  10. Infrared study of H 1743-322 in outburst: a radio-quiet and NIR-dim microquasar

    NASA Astrophysics Data System (ADS)

    Chaty, S.; Muñoz Arjonilla, A. J.; Dubus, G.

    2015-05-01

    Context. Microquasars are accreting Galactic sources that are commonly observed to launch relativistic jets. One of the most important issues regarding these sources is the energy budget of ejections relative to the accretion of matter. Aims: The X-ray binary, black hole candidate, and microquasar H 1743-322 exhibited a series of X-ray outbursts between 2003 and 2008. We took optical and near-infrared (OIR) observations with the ESO/NTT telescope during three of these outbursts (2003, 2004, and 2008). The goals of these observations were to investigate the presence of a jet, and to disentangle the various contributions constituting the spectral energy distribution (SED): accretion, ejection, and stellar emission. Methods: Photometric and spectroscopic OIR observations allowed us to produce a high time-resolution lightcurve in Ks-band, to analyze emission lines present in the IR spectra, to construct a multiwavelength SED including radio, IR, and X-ray data, and to complete the OIR vs. X-ray correlation of black hole binaries with H 1743-322 data points. Results: We detect rapid flares of duration ~5 min in the high time-resolution IR lightcurve. We identify hydrogen and helium emission lines in the IR spectra, coming from the accretion disk. The IR SED exhibits the spectral index typically associated with the X-ray high, soft state in our observations taken during the 2003 and 2004 outbursts, while the index changes to one that is typical of the X-ray low, hard state during the 2008 outburst. During this last outburst, we detected a change of slope in the NIR spectrum between the J and Ks bands, where the JH part is characteristic of an optically thick disk emission, while the HKs part is typical of optically thin synchrotron emission. Furthermore, the comparison of our IR data with radio and X-ray data shows that H 1743-322 exhibits a faint jet both in radio and NIR domains. Finally, we suggest that the companion star is a late-type main sequence star located in

  11. XMM-Newton Spectroscopy of the Galactic Microquasar GRS 1758-258 in the Peculiar Off/Soft State

    NASA Technical Reports Server (NTRS)

    Miller, J. M.; Wunands, R.; Rodriguez-Pascual, P. M.; Ferrando, P.; Gaensler, B. M.; Goldwurm, A.; Lewin, W. H. G.; Pooley, D.

    2002-01-01

    We report on an XMM-Newton Reflection Grating Spectrometer observation of the black hole candidate and Galactic microquasar GRS 1758-258. The source entered a peculiar "off/soft" state in 2001 late February in which the spectrum softened while the X-ray flux-and the inferred mass accretion rate-steadily decreased. We find no clear evidence for emission or absorption lines in the dispersed spectra, indicating that most of the observed soft flux is likely from an accretion disk and not from a cool plasma. The accretion disk strongly dominates the spectrum in this lower luminosity state and is only mildly recessed from the marginally stable orbit. These findings may be di8licult to explain in terms of advection-dominated accretion flow (ADAF) models. We discuss these results within the context of ADAF models, simultaneous two-flow models, and observed correlations between hard X-ray flux and jet production.

  12. XMM-Newton Spectroscopy of the Galactic Microquasar GRS 1758-258 in the Peculiar Off/Soft State

    NASA Technical Reports Server (NTRS)

    Miller, J. M.; Wunands, R.; Rodriguez-Pascual, P. M.; Ferrando, P.; Gaensler, B. M.; Goldwurm, A.; Lewin, W. H. G.; Pooley, D.

    2002-01-01

    We report on an XMM-Newton Reflection Grating Spectrometer observation of the black hole candidate and Galactic microquasar GRS 1758-258. The source entered a peculiar "off/soft" state in 2001 late February in which the spectrum softened while the X-ray flux-and the inferred mass accretion rate-steadily decreased. We find no clear evidence for emission or absorption lines in the dispersed spectra, indicating that most of the observed soft flux is likely from an accretion disk and not from a cool plasma. The accretion disk strongly dominates the spectrum in this lower luminosity state and is only mildly recessed from the marginally stable orbit. These findings may be di8licult to explain in terms of advection-dominated accretion flow (ADAF) models. We discuss these results within the context of ADAF models, simultaneous two-flow models, and observed correlations between hard X-ray flux and jet production.

  13. Detection of a Relativistic Outflow from the Galactic Microquasar GRS 1758-258 in the Hard State

    NASA Astrophysics Data System (ADS)

    Reynolds, Mark; Miller, Jon; Cackett, Edward; King, Ashley

    2016-07-01

    Outflows in the form of collimated jets and wider angle winds are observed ubiquitously from accreting systems. Herein, we present the results of a Suzaku observation of the persistent Galactic microquasar GRS 1758-258 at a luminosity of ˜1% L_{Edd}. Spectral analysis reveals the presence of an absorption feature at an energy of ˜7.5 keV, consistent with the presence of a relativistic outflow (v ˜0.1c). Photo-ionization modeling with XSTAR finds this wind to be highly ionized consistent with absorption by Fe XXVI at a distance of ˜2700 R_g from the black hole. This is the highest velocity wind detected from a stellar mass black hole accretion flow to date, and represents the first detection of a photo-ionized outflow in the hard spectral state, demonstrating the persistent of the wind outflow mechanism down to luminosities of at least 1% L_{Edd}.

  14. The low or retrograde spin of the first extragalactic microquasar: implications for Blandford-Znajek powering of jets

    NASA Astrophysics Data System (ADS)

    Middleton, Matthew J.; Miller-Jones, James C. A.; Fender, Rob P.

    2014-04-01

    Transitions to high mass accretion rates in black hole X-ray binaries are associated with the ejection of powerful, relativistically moving jets. The mechanism that powers such events is thought to be linked to tapping of the angular momentum (spin) of the black hole, the rate of accretion through the disc or some combination of the two. We can attempt to discriminate between these different possibilities by comparing proxies for jet power with spin estimates. Because of the small number of sources that reach Eddington mass accretion rates and have therefore been suggested to act as `standard candles', there has been much recent debate as to whether a significant correlation exists between jet power and black hole spin. We perform continuum fitting to the high-quality, disc-dominated XMM-Newton spectra of the extragalactic microquasar discovered in M31. Assuming prograde spin, we find that for sensible constraints the spin is always very low (a* ≤ 0.15 at 3σ). When combined with a proxy for jet power derived from the maximum 5 GHz radio luminosity during a bright flaring event, we find that the source sits well above the previously reported, rising correlation that would indicate that spin tapping is the dominant mechanism for powering the jets, i.e. it is too `radio loud' for such a low spin. The notable exceptions require the inclination to be improbably small or the jet to be very fast. We investigate whether this could be a byproduct of selecting prograde-only spin, finding that the data statistically favour a substantially retrograde spin for the same constraints (a* ≤-0.17 at 3σ). Although theoretically improbable, this remarkable finding could be confirmation that retrograde spin can power such jets via spin-tapping, as has been suggested for certain radio quasars. In either case this work demonstrates the value of studying local extragalactic microquasars as a means to better understand the physics of jet launching.

  15. The effects of the stellar wind and orbital motion on the jets of high-mass microquasars

    NASA Astrophysics Data System (ADS)

    Bosch-Ramon, V.; Barkov, M. V.

    2016-05-01

    Context. High-mass microquasar jets propagate under the effect of the wind from the companion star, and the orbital motion of the binary system. The stellar wind and the orbit may be dominant factors determining the jet properties beyond the binary scales. Aims: This is an analytical study, performed to characterise the effects of the stellar wind and the orbital motion on the jet properties. Methods: Accounting for the wind thrust transferred to the jet, we derive analytical estimates to characterise the jet evolution under the impact of the stellar wind. We include the Coriolis force effect, induced by orbital motion and enhanced by the wind's presence. Large-scale evolution of the jet is sketched, accounting for wind-to-jet thrust transfer, total energy conservation, and wind-jet flow mixing. Results: If the angle of the wind-induced jet bending is larger than its half-opening angle, the following is expected: (i) a strong recollimation shock; (ii) bending against orbital motion, caused by Coriolis forces and enhanced by the wind presence; and (iii) non-ballistic helical propagation further away. Even if disrupted, the jet can re-accelerate due to ambient pressure gradients, but wind entrainment can weaken this acceleration. On large scales, the opening angle of the helical structure is determined by the wind-jet thrust relation, and the wind-loaded jet flow can be rather slow. Conclusions: The impact of stellar winds on high-mass microquasar jets can yield non-ballistic helical jet trajectories, jet partial disruption and wind mixing, shocks, and possibly non-thermal emission. Among other observational diagnostics, such as radiation variability at any band, the radio morphology on milliarcsecond scales can be informative on the wind-jet interaction.

  16. X-1E on Display Stand at Dryden

    NASA Technical Reports Server (NTRS)

    1988-01-01

    A photo showing the Bell Aircraft Corporation X-1E mounted at a jaunty angle in front of the main building (4800) at NASA Dryden Flight Research Center, Edwards, California. The X-1E began life as the X-1-2, a first generation aircraft. The X-1E flew twenty-six times with two pilots. It was retired on November 6, 1958. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and

  17. Merger shocks in Abell 3667 and the Cygnus A cluster

    NASA Astrophysics Data System (ADS)

    Sarazin, C. L.; Finoguenov, A.; Wik, D. R.

    2013-04-01

    We present new XMM-Newton observations of the northwest (NW) radio relic region in the cluster Abell 3667. We detect a jump in the X-ray surface brightness and X-ray temperature at the sharp outer edge of the radio relic which indicate that this is the location of a merger shock with a Mach number of about 2. Comparing the radio emission to the shock properties implies that approximately 0.2% of the dissipated shock kinetic energy goes into accelerating relativistic electrons. This is an order of magnitude smaller than the efficiency of shock acceleration in many Galactic supernova remnants, which may be due to the lower Mach numbers of cluster merger shocks. The X-ray and radio properties indicate that the magnetic field strength in the radio relic is ⪆ 3 μG, which is a very large field at a projected distance of ˜ 2.2 Mpc from the center of a cluster. The radio spectrum is relatively flat at the shock, and steepens dramatically with distance behind the shock. This is consistent with radiative losses by the electrons and the post-shock speed determined from the X-ray properties. The Cygnus A radio source is located in a merging cluster of galaxies. This appears to be an early-stage merger. Our recent Suzaku observation confirm the presence of a hot region between the two subclusters which agrees with the predicted shocked region. The high spectral resolution of the CCDs on Suzaku allowed us to measure the radial component of the merger velocity, Δ v_r ≈ 2650 km s-1.

  18. 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'.

  19. 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.

  20. 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.

  1. A NEW GALACTIC EXTINCTION MAP OF THE CYGNUS REGION

    SciTech Connect

    Kohyama, T.; Shibai, H.; Fukagawa, M.; Hibi, Y.

    2010-08-10

    We have made a Galactic extinction map of the Cygnus region with 5' spatial resolution. The selected area is 80{sup 0} to 90{sup 0} in the Galactic longitude and -4{sup 0} to 8{sup 0} in the Galactic latitude. The intensity at 140 {mu}m is derived from the intensities at 60 and 100 {mu}m of the IRAS data using the tight correlation between 60, 100, and 140 {mu}m found in the Galactic plane. The dust temperature and optical depth are calculated with 5' resolution from the 140 and 100 {mu}m intensity, and A{sub V} is calculated from the optical depth. In the selected area, the mean dust temperature is 17 K, the minimum is 16 K, and the maximum is 30 K. The mean A{sub V} is 6.5 mag, the minimum is 0.5 mag, and the maximum is 11 mag. The dust temperature distribution shows significant spatial variation on smaller scales down to 5'. Because the present study can trace the 5'-scale spatial variation of the extinction, it has an advantage over the previous studies, such as the one by Schlegel, Finkbeiner, and Davis, who used the COBE/DIRBE data to derive the dust temperature distribution with a spatial resolution of 1{sup 0}. The difference of A{sub V} between our map and Schlegel et al.'s is {+-} 3 mag. A new extinction map of the entire sky can be produced by applying the present method.

  2. Search for Cygnus X-3 in underground muons during the 1989 radio outbursts using the IMB detector

    SciTech Connect

    Becker-Szendy, R.; Bratton, C.B.; Cady, R.; Casper, D.; Dye, S.T.; Gajewski, W.; Goldhaber, M.; Haines, T.J.; Halverson, P.G.; Jones, T.W.; Kielczewska, D.; Kropp, W.R.; Learned, J.G.; LoSecco, J.M.; Matsuno, S.; McGrew, C.; Mudan, M.S.; Price, L.; Reines, F.; Schultz, J.; Sobel, H.W.; Stone, J.L.; Sulak, L.R.; Svoboda, R.; Wittel, F. The University of Michigan, Ann Arbor, Michigan 48019 Brookhaven National Laboratory, Upton, New York 11973 Boston University, Boston, Massachusetts 02215 The University of Hawaii, Honolulu, Hawaii 96822 University College, London, WC1 E6BT, United Kingdom Warsaw University, Warsaw, Poland Cleveland State University, Cleveland, Ohio 44115 The University of Notre Dame, Notre Dame, Indiana 46556 Louisiana State University, Baton Rouge, Lousiana 70803 The University of Maryland, College Park, Maryland 20742)

    1991-02-15

    A search is made for underground muons from Cygnus X-3 with the Irvine-Michigan-Brookhaven IMB-3 detector around the time of the 1989 radio outbursts. No long-term pulsed signal is found in a sample of 11 117 underground muons collected from the direction of Cygnus X-3. We place an upper limit of 3{times}10{sup {minus}10} cm{sup {minus}2} sec{sup {minus}1} on the flux of underground muons from Cygnus X-3.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    DTIC Science & Technology

    2013-06-01

    Held in San Francisco , CA on 16-21 June 2013., The original document contains color images. 14. ABSTRACT Cygnus is a high-energy radiographic x-ray...E. Maenchen, C. V. Mitton, I. Molina, H. Nishimoto, E. C. Ormond, P. A. Ortega , R. J. Quicksilver, R. N. Ridlon, E. A. Rose, D. W. Scholfield, I

  5. Changes in trumpeter swan (Cygnus buccinator) activities from winter to spring in the greater Yellowstone area

    Treesearch

    John R. Squires; Stanley H. Anderson

    1997-01-01

    Trumpeter swans (Cygnus buccinator), in the winter, primarily, slept 42% of the time, fed 30%, swam 12%; and preened 7%. Comparisons of swan activities among die periods during the winter indicated they increased feeding throughout the day into night, when they fed at their highest rate. Swans spent more time sleeping as winter temperatures decreased; feeding...

  6. THE PROTOPLANETARY DISKS IN THE NEARBY MASSIVE STAR-FORMING REGION CYGNUS OB2

    SciTech Connect

    Guarcello, M. G.; Drake, J. J.; Wright, N. J.; Hora, J. L.; Aldcroft, T.; Fruscione, A.; Kashyap, V. L.; Drew, J. E.; Gutermuth, R. A.; Naylor, T.; King, R.; Garcia-Alvarez, D.

    2013-08-20

    The formation of stars in massive clusters is one of the main modes of the star formation process. However, the study of massive star-forming regions is hampered by their typically large distances to the Sun. One exception to this is the massive star-forming region Cygnus OB2 in the Cygnus X region, at the distance of {approx}1400 pc. Cygnus OB2 hosts very rich populations of massive and low-mass stars, being the best target in our Galaxy to study the formation of stars, circumstellar disks, and planets in the presence of massive stars. In this paper, we combine a wide and deep set of photometric data, from the r band to 24 {mu}m, in order to select the disk-bearing population of stars in Cygnus OB2 and identify the class I, class II, and stars with transition and pre-transition disks. We selected 1843 sources with infrared excesses in an area of 1 Degree-Sign Multiplication-Sign 1 Degree-Sign centered on Cyg OB2 in several evolutionary stages: 8.4% class I, 13.1% flat-spectrum sources, 72.9% class II, 2.3% pre-transition disks, and 3.3% transition disks. The spatial distribution of these sources shows a central cluster surrounded by an annular overdensity and some clumps of recent star formation in the outer region. Several candidate subclusters are identified, both along the overdensity and in the rest of the association.

  7. TeV flaring activity of Cygnus X-3 during 13 years

    NASA Astrophysics Data System (ADS)

    Sinitsyna, V. G.; Alaverdian, A. Y.; Mirzafatikhov, R. M.; Musin, F. I.; Nikolsky, S. I.; Sinitsyna, V. Y.; Platonov, G. F.

    2009-12-01

    Cygnus X-3 is a peculiar X-ray binary system discovered about 40 years ago. The system has been observed throughout a wide range of the electromagnetic spectrum. It is one of the brightest Galactic X-ray sources, displaying high and low states and a rapid variability in X-rays. It is also the strongest radio source among X-ray binaries and shows both huge radio outbursts and relativistic jets. Based on the detection of ultra high energy gamma-rays, Cygnus X-3 has been suggested as one of the most powerful sources of charged cosmic ray particles in the Galaxy. The galactic source Cygnus X-3, has been regularly observed since 1995 with an average gamma-quantum flux of F(E>0.8TeV)=(6.2±0.5)×10-13cm-2s-1. The binary Cyg X-3 came to a new period of flaring activity at radio- and X-ray energies in 2006. In May and July 2006 a significant increase of Cyg X-3 flux was detected by SHALON at TeV energies. Earlier, in 1997 and 2003, a comparable increase of the flux over the average value was also observed. These results provide evidence for a variability of the flux. Confirmation of the variability of very high-energy gamma radiation from Cygnus X-3 by future observations would be important for understanding the nature of this astrophysical object.

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

    SciTech Connect

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

    2010-09-01

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

  9. 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.

  10. Orbital ATK Cygnus Cargo Module Ready for Delivery to International Space Station

    NASA Image and Video Library

    2017-04-13

    The Orbital ATK Cygnus pressurized cargo module is packed with science experiments, supplies and hardware for delivery to the International Space Station on CRS-7. Orbital ATK's seventh commercial resupply services mission will launch atop a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station in Florida.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. X-1E Loaded in B-29 Mothership on Ramp

    NASA Technical Reports Server (NTRS)

    1955-01-01

    The Bell Aircraft Corporation X-1E loaded into the Boeing B-29 in NACA High Speed Flight Station service area. The B-29 would carry the X-1E to an altitude of approximately 25,000 feet. If all systems were `go' the aircraft would be launched. The pilot would activate the rocket engines and follow a pre-determined flight plan for altitude and speed, doing other maneuvers as requested, returning on a glide path to the Rogers Dry Lakebed for a touch down. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force

  16. The Role of Fast Magnetic Reconnection on the Radio and Gamma-ray Emission from the Nuclear Regions of Microquasars and Low Luminosity AGNs

    NASA Astrophysics Data System (ADS)

    Kadowaki, L. H. S.; de Gouveia Dal Pino, E. M.; Singh, C. B.

    2015-04-01

    Fast magnetic reconnection events can be a very powerful mechanism operating in the core region of microquasars and active galactic nuclei (AGNs). In earlier work, it has been suggested that the power released by fast reconnection events between the magnetic field lines lifting from the inner accretion disk region and the lines anchored into the central black hole could accelerate relativistic particles and produce the observed radio emission from microquasars and low luminosity AGNs (LLAGNs). Moreover, it has been proposed that the observed correlation between the radio emission and the mass of these sources, spanning 1010 orders of magnitude in mass, might be related to this process. In the present work, we revisit this model comparing two different fast magnetic reconnection mechanisms, namely, fast reconnection driven by anomalous resistivity (AR) and by turbulence. We apply the scenario above to a much larger sample of sources (including also blazars, and gamma-ray bursts—GRBs), and find that LLAGNs and microquasars do confirm the trend above. Furthermore, when driven by turbulence, not only their radio but also their gamma-ray emission can be due to magnetic power released by fast reconnection, which may accelerate particles to relativistic velocities in the core region of these sources. Thus the turbulent-driven fast reconnection model is able to reproduce verywell the observed emission. On the other hand, the emission from blazars and GRBs does not follow the same trend as that of the LLAGNs and microquasars, indicating that the radio and gamma-ray emission in these cases is produced beyond the core, along the jet, by another population of relativistic particles, as expected.

  17. THE ROLE OF FAST MAGNETIC RECONNECTION ON THE RADIO AND GAMMA-RAY EMISSION FROM THE NUCLEAR REGIONS OF MICROQUASARS AND LOW LUMINOSITY AGNs

    SciTech Connect

    Kadowaki, L. H. S.; Pino, E. M. de Gouveia Dal; Singh, C. B. E-mail: dalpino@iag.usp.br

    2015-04-01

    Fast magnetic reconnection events can be a very powerful mechanism operating in the core region of microquasars and active galactic nuclei (AGNs). In earlier work, it has been suggested that the power released by fast reconnection events between the magnetic field lines lifting from the inner accretion disk region and the lines anchored into the central black hole could accelerate relativistic particles and produce the observed radio emission from microquasars and low luminosity AGNs (LLAGNs). Moreover, it has been proposed that the observed correlation between the radio emission and the mass of these sources, spanning 10{sup 10} orders of magnitude in mass, might be related to this process. In the present work, we revisit this model comparing two different fast magnetic reconnection mechanisms, namely, fast reconnection driven by anomalous resistivity (AR) and by turbulence. We apply the scenario above to a much larger sample of sources (including also blazars, and gamma-ray bursts—GRBs), and find that LLAGNs and microquasars do confirm the trend above. Furthermore, when driven by turbulence, not only their radio but also their gamma-ray emission can be due to magnetic power released by fast reconnection, which may accelerate particles to relativistic velocities in the core region of these sources. Thus the turbulent-driven fast reconnection model is able to reproduce verywell the observed emission. On the other hand, the emission from blazars and GRBs does not follow the same trend as that of the LLAGNs and microquasars, indicating that the radio and gamma-ray emission in these cases is produced beyond the core, along the jet, by another population of relativistic particles, as expected.

  18. 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.

  19. X-1E Loaded in B-29 Mothership on Ramp

    NASA Technical Reports Server (NTRS)

    1955-01-01

    The Bell Aircraft Corporation X-1E airplane being loaded under the mothership, Boeing B-29. The X planes had originally been lowered into a loading pit and the launch aircraft towed over the pit, where the rocket plane was hoisted by belly straps into the bomb bay. By the early 1950s a hydraulic lift had been installed on the ramp at the NACA High-Speed Flight Station to elevate the launch aircraft and then lower it over the rocket plane for mating. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force

  20. X-1E Being Loaded on B-29 Mothership

    NASA Technical Reports Server (NTRS)

    1955-01-01

    The Bell Aircraft Corporation X-1E being loaded under the Boeing B-29 in preparation for a NACA High-Speed Flight Station captive flight in 1955. One rocket technician is servicing the aircraft while another technician is busy 'buttoning' up an inspection panel. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and an altitude of 43,000 feet. The number 2 X-1 was modified

  1. X-1E on Display Stand at Dryden

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Bell Aircraft Corporation X-1E is shown in this artistic night photo taken in February 1996. This aircraft is displayed on a pedestal in front of the main building (4800) at NASA Dryden Flight Research Center, Edwards, California. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and an altitude of 43,000 feet. The number 2 X-1 was modified and redesignated the X-1E

  2. X-1-2 mounted under B-29 for launch

    NASA Technical Reports Server (NTRS)

    1949-01-01

    A roll-out of the Boeing B-29 Superfortress, bomber with the Bell Aircraft Corporation X-1-2 mated and ready for flight. NACA Flight 33 was flown on September 23, 1949, as a pilot familiarization flight with NACA pilot, John H. Griffith at the controls. Griffith reached a top speed of Mach 0.998 during the flight. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on Jan. 25, 1946. Powered flights began in December 1946. On Oct. 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and an altitude of

  3. X-1E Loaded in B-29 Mothership on Ramp

    NASA Technical Reports Server (NTRS)

    1955-01-01

    The Bell Aircraft Corporation X-1E airplane being loaded under the mothership, Boeing B-29. The X planes had originally been lowered into a loading pit and the launch aircraft towed over the pit, where the rocket plane was hoisted by belly straps into the bomb bay. By the early 1950s a hydraulic lift had been installed on the ramp at the NACA High-Speed Flight Station to elevate the launch aircraft and then lower it over the rocket plane for mating. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force

  4. 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 ...

  5. 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 ...

  6. X-1-2 with Pilots Robert Champine Herb Hoover

    NASA Technical Reports Server (NTRS)

    1949-01-01

    The Bell Aircraft Corporation X-1-2 and two of the NACA pilots that flew the aircraft. The one on the left is Robert Champine with the other being Herbert Hoover. The X-1-2 was also equipped with the 10-percent wing and 8 percent tail, powered with an XLR-11 rocket engine and aircraft made its first powered flight on December 9, 1946 with Chalmers 'Slick' Goodlin at the controls. As with the X-1-1 the X-1-2 continued to investigate transonic/supersonic flight regime. NACA pilot Herbert Hoover became the first civilian to fly Mach 1, March 10, 1948. X-1-2 flew until October 23, 1951, completing 74 glide and powered flights with nine different pilots, when it was retired to be rebuilt as the X-1E.

  7. 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).

  8. 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.

  9. 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.

  10. 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

  11. Maintenance Production Management (2R1X1)

    DTIC Science & Technology

    2007-11-02

    Occupational Survey Report Burke Burright Occupational Analyst 2R1X1 MAINTENANCE PRODUCTION MANAGEMENT MARCH 2001 Air Force Occupational Measurement...34DD MON YYYY") Title and Subtitle Occupational Survey Report 2R1X1 Maintenance Production Management Contract or Grant Number Program Element...AFSC AWARDING COURSE § Maintenance Production Management Apprentice (J3ABR2R1X1-003) § 6 Weeks, 1 day § 12 Semester Hours for CCAF § Sheppard AFB, TX

  12. 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

  13. Chandra Discovers the X-ray Signature of a Powerful Wind from a Galactic Microquasar

    NASA Astrophysics Data System (ADS)

    2000-11-01

    NASA's Chandra X-ray Observatory has detected, for the first time in X rays, a stellar fingerprint known as a P Cygni profile--the distinctive spectral signature of a powerful wind produced by an object in space. The discovery reveals a 4.5-million-mile-per-hour wind coming from a highly compact pair of stars in our galaxy, report researchers from Penn State and the Massachusetts Institute of Technology in a paper they will present on 8 November 2000 during a meeting of the High-Energy Astrophysics Division of the American Astronomical Society in Honolulu, Hawaii. The paper also has been accepted for publication in The Astrophysical Journal Letters. "To our knowledge, these are the first P Cygni profiles reported in X rays," say researchers Niel Brandt, assistant professor of astronomy and astrophysics at Penn State, and Norbert S. Schulz, research scientist at the Massachusetts Institute of Technology. The team made the discovery during their first observation of a binary-star system with the Chandra X-ray Observatory, which was launched into space in July 1999. The system, known as Circinus X-1, is located about 20,000 light years from Earth in the constellation Circinus near the Southern Cross. It contains a super-dense neutron star in orbit around a normal fusion-burning star like our Sun. Although Circinus X-1 was discovered in 1971, many properties of this system remain mysterious because Circinus X-1 lies in the galactic plane where obscuring dust and gas have blocked its effective study in many wavelengths. The P Cygni spectral profile, previously detected primarily at ultraviolet and optical wavelengths but never before in X rays, is the textbook tool astronomers rely on for probing stellar winds. The profile looks like the outline of a roller coaster, with one really big hill and valley in the middle, on a data plot with velocity on one axis and the flow rate of photons per second on the other. It is named after the famous star P Cygni, in which such

  14. High-Frequency Quasi-Periodic Oscillations in the 2000 Outburst of the Galactic Microquasar XTE J1550-564

    NASA Technical Reports Server (NTRS)

    Miller, J. M.; Wijnands, R.; Homan, J.; Belloni, T.; Pooley, D.; Kouveliotou, C.; vanderKlis, M.; Lewin, W. H. G.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    We present an analysis of the high-frequency timing properties of the April-May 2000 outburst of the black hole candidate and Galactic microquasar XTE J1550-564, measured with the Rossi X-ray Timing Explorer, The rapid X-ray variability we measure is consistent with the source being in either the "very high" or "intermediate" canonical black hole state. A strong (5-8% RMS) quasi-periodic oscillation (QPO) is found between 249-278 Hz; this may represent the first recurrence of the same high-frequency QPO in subsequent outbursts of a transient black hole candidate. We also present possible evidence for a lower-frequency QPO at approximately 187 Hz, also reported previously and likely present simultaneously with the higher-frequency QPO. We discuss these findings within the context of the 1998 outburst of XTE J1550-564, and comment on implications for models of QPOs, accretion flows, and black hole spin.

  15. Long term X-ray variability of Circinus X-1

    SciTech Connect

    Saz Parkinson, Pablo

    2003-03-19

    We present an analysis of long term X-ray monitoring observations of Circinus X-1 (Cir X-1) made with four different instruments: Vela 5B, Ariel V ASM, Ginga ASM, and RXTE ASM, over the course of more than 30 years. We use Lomb-Scargle periodograms to search for the {approx}16.5 day orbital period of Cir X-1 in each of these data sets and from this derive a new orbital ephemeris based solely on X-ray measurements, which we compare to the previous ephemerides obtained from radio observations. We also use the Phase Dispersion Minimization (PDM) technique, as well as FFT analysis, to verify the periods obtained from periodograms. We obtain dynamic periodograms (both Lomb-Scargle and PDM) of Cir X-1 during the RXTE era, showing the period evolution of Cir X-1, and also displaying some unexplained discrete jumps in the location of the peak power.

  16. 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.

  17. Investigating Star-Gas Correlation and Evolution in the 100pc Cygnus X Complex

    NASA Astrophysics Data System (ADS)

    Gutermuth, Robert A.; Heyer, Mark H.; Offner, Stella

    2017-01-01

    We present a new analysis of the 25 square degree Cygnus-X Spitzer Legacy Survey. At 100 pc across and over a million solar masses, the Cygnus X molecular cloud complex is a true giant, dwarfing the nearby Orion clouds by an order of magnitude in mass. With our updated reduction of the mid-IR imaging survey and inclusion of UKIDSS near-IR photometry, we have produced a new catalog of over 20,000 young stellar objects with IR excess emission. In addition, we have constructed an associated completeness mapping product that characterizes relative sensitivity as a function of luminosity and spectral energy distribution shape. We will present early analysis from these new data products and extant maps of gas column density from the FCRAO 14m telescope that aims to explore environmental effects on the star-gas correlation at a range of size scales.

  18. X-1E on Lakebed with Collapsed Nose Gear

    NASA Technical Reports Server (NTRS)

    1956-01-01

    This photo was taken June 18, 1956 on Rogers Dry Lakebed after Flight 7 of the Bell Aircraft Corporation X-1E with NACA High-Speed Flight Station test pilot Joseph `Joe' Walker at the controls. The first generation X-1s were well known for nose gear failures and the X-1E was no exception. The hard pitch down on landing usually resulted in a collapsed nose gear. The damage rarely was serious but required several days of down-time for repair. The X-1E was the only one to have a true tail skid to protect the empennage from over-rotation during landing. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25

  19. X-1-2 on ramp with Boeing B-29

    NASA Technical Reports Server (NTRS)

    1949-01-01

    The Bell Aircraft Corporation X-1-2 Sitting on the ramp at NACA High-Speed Flight Research Station with the Boeing B-29 launch ship behind. The painting near the nose of the B-29 depicts a stork carrying a bundle which is symbolic of the Mothership launching her babe (X-1-2). The pilot access door is open to the cockpit of the X-1-2 aircraft. On the X-1-2's fin is the old NACA shield, which was later replaced with a yellow band and the letters 'NACA' plus wings that were both black. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on Jan. 25, 1946. Powered flights began in December 1946. On Oct. 14, 1947, the X-1

  20. Severe lead poisoning and an abdominal foreign body in a mute swan (Cygnus olor).

    PubMed

    Cousquer, Glen O

    2006-09-01

    The mute swan (Cygnus olor) is common on British waterways and frequently presents to wildlife hospitals with fishing tackle-related problems. Many of these birds have abnormally high blood lead levels after the ingestion of lead fishing weights. The ingestion of fishing line and tackle is also commonly seen. This case report describes the treatment of a swan with a particularly severe case of lead poisoning and the subsequent removal of an abdominal foreign body.

  1. 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.

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

    PubMed Central

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

    2012-01-01

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

  3. Search for gamma rays of energy 10(15) eV from Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Bhat, P. N.; Rajeev, M. R.; Ramanamurthy, P. V.; Rao, M. V. S.; Sinha, S.; Sreekantan, B. V.; Tonwar, S. C.; Vishwanath, P. R.

    1985-01-01

    Finite flux of excess radiation of energy 10 to the 15th power has been reported by two groups from the direction of Cygnus X-3, with the characteristic periodicity of 4.8 hrs. Samorski and Stamm find that the muon content of the showers generated by this excess radiation is about 77% of that in normal cosmic ray showers, whereas the expectation for gamma ray showers is less than 10%. It is thus difficult to understand the nature of the radiation arriving from the direction of Cygnus X-3. Samorski and Stamm measured the muon densities close to the core (approx. 10 m), where contamination due to other components is severe. Even though this does not explain the high ratio of muon densities, measurements should be carried out away from the core to establish the nature of the radiation. In order to establish the signal from Cygnus X-3 and its muon content with better statistical significance, an extensive air shower array, specifically designed for this purpose was operated at Kolar Gold Fields (longitude: 78 deg .3 E; latitude: + 12 deg .95; atmospheric depth: 920 q/square centimeters) since September, 1984. The details of the array and the accuracy of arrival direction measurements are discussed.

  4. Analysis of the kinematic structure of the Cygnus OB1 association

    NASA Astrophysics Data System (ADS)

    Costado, M. T.; Alfaro, E. J.; González, M.; Sampedro, L.

    2017-03-01

    The main objective of this study is the characterization of the velocity field in the Cygnus OB1 association using the radial velocity data currently available in the literature. This association is part of a larger star-forming complex located in the direction of the Cygnus region, but whose main subsystems may be distributed at different distances from the sun. We have collected radial velocity data for more than 300 stars in the area of 5 × 5 deg2 centred on the Cygnus OB1 association. We present the results of a kinematic clustering analysis in the subspace of the phase space formed by angular coordinates and radial velocity using two independent methodologies. We have found evidence of structure in the phase space with the detection of two main groups, corresponding to different radial velocity and distance values, belonging to the association, and associated with two main shells defined by the Hα emission. A third grouping well separated from the other two in velocity appears to occupy the whole region associated with what has been called 'common shell'.

  5. 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.

  6. 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.

  7. DISCOVERY OF A PULSAR WIND NEBULA CANDIDATE IN THE CYGNUS LOOP

    SciTech Connect

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

    2012-07-20

    We report on a discovery of a diffuse nebula containing a pointlike 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 pointlike 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 pointlike} {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 2.1 Multiplication-Sign 10{sup 31} (d/540 pc){sup 2} erg s{sup -1}, where d is the distance to the Loop. This implies a spin-down loss-energy E-dot {approx}2.6 Multiplication-Sign 10{sup 35} (d/540 pc){sup 2} erg s{sup -1}. The location of the neutron star candidate, {approx}2 Degree-Sign away from the geometric center of the Loop, implies a high transverse velocity of {approx}1850 ({theta}/2 Degree-Sign ) (d/540 pc) (t/10 kyr){sup -1} km s{sup -1}, assuming the currently accepted age of the Cygnus Loop.

  8. A kinematic and proper-motion survey of the Cygnus Loop

    NASA Technical Reports Server (NTRS)

    Shull, Peter, Jr.; Hippelein, Hans

    1991-01-01

    H-alpha radial velocities, line widths, and line intensities based on 71 Fabry-Perot interferometer scans of 61 fields in the Cygnus Loop supernova remnant SNR are reported. Also, measurements of proper motions at 39 locations within the Cygnus Loop are summarized. These results show that the remnant is expanding asymmetrically into the ambient interstellar medium, with rest-frame velocities as high as 380 km/s in the near half and 150 km/s in the far half. This can plausibly be interpreted as the result of the progenitor's evolution near a density discontinuity, the consequent formation of a cavity and partial shell, and the SN's interaction with that shell. The remnant's optically observed filamentary structure results from line-of-sight effects as shock waves advance into the irregular inner surface of the shell. In this context, the derived expansion velocities and proper motions give a formal distance to the Cygnus Loop of roughly 600 pc, with 1-sigma limits of 300 and 1200 pc.

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

    NASA Astrophysics Data System (ADS)

    McCall, Benjamin J.; Oka, Takeshi

    2000-08-01

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

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

    SciTech Connect

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

    2015-06-01

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

  11. A kinematic and proper-motion survey of the Cygnus Loop

    NASA Technical Reports Server (NTRS)

    Shull, Peter, Jr.; Hippelein, Hans

    1991-01-01

    H-alpha radial velocities, line widths, and line intensities based on 71 Fabry-Perot interferometer scans of 61 fields in the Cygnus Loop supernova remnant SNR are reported. Also, measurements of proper motions at 39 locations within the Cygnus Loop are summarized. These results show that the remnant is expanding asymmetrically into the ambient interstellar medium, with rest-frame velocities as high as 380 km/s in the near half and 150 km/s in the far half. This can plausibly be interpreted as the result of the progenitor's evolution near a density discontinuity, the consequent formation of a cavity and partial shell, and the SN's interaction with that shell. The remnant's optically observed filamentary structure results from line-of-sight effects as shock waves advance into the irregular inner surface of the shell. In this context, the derived expansion velocities and proper motions give a formal distance to the Cygnus Loop of roughly 600 pc, with 1-sigma limits of 300 and 1200 pc.

  12. Cygnus X-2, super-Eddington mass transfer, and pulsar binaries

    NASA Astrophysics Data System (ADS)

    King, A. R.; Ritter, H.

    1999-10-01

    We consider the unusual evolutionary state of the secondary star in Cygnus X-2. Spectroscopic data give a low mass (M_2~=0.5-0.7M_solar) and yet a large radius (R_2~=7R_solar) and high luminosity (L_2~=150L_solar). We show that this star closely resembles a remnant of early massive Case B evolution, during which the neutron star ejected most of the ~3M_solar transferred from the donor (initial mass M_2i~3.6M_solar) on its thermal time-scale ~10^6yr. As the system is far too wide to result from common-envelope evolution, this strongly supports the idea that a neutron star efficiently ejects the excess inflow during super-Eddington mass transfer. Cygnus X-2 is unusual in having had an initial mass ratio q_iM_2iM_1 in a narrow critical range near q_i~=2.6. Smaller q_i lead to long-period systems with the former donor near the Hayashi line, and larger q_i to pulsar binaries with shorter periods and relatively massive white dwarf companions. The latter naturally explain the surprisingly large companion masses in several millisecond pulsar binaries. Systems like Cygnus X-2 may thus be an important channel for forming pulsar binaries.

  13. 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.

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

    SciTech Connect

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

    2015-10-01

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

  15. X-1-2 on ramp during ground engine test

    NASA Technical Reports Server (NTRS)

    1947-01-01

    Ground engine test run on the Bell Aircraft Corporation X-1-2 airplane at NACA Muroc Flight Test Unit service area. Notice the front on the lower part of the aircraft aft of the nose section. The frost forms from the mixture of the propellants (including liquid oxygen) in the internal tanks. This photograph was taken in 1947. The aircraft shown is still painted in its original saffron (orange) paint finish. This was later changed to white, which was more visible against the dark blue sky than saffron turned out to be. There were four versions of the Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Sonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on Jan. 25, 1946. Powered flights began in December

  16. Right side view of Bell X-1 #6063

    NASA Image and Video Library

    1951-12-15

    The Bell Aircraft Corporation X-1-2 aircraft on the ramp at NACA High Speed Flight Research Station located on the South Base of Muroc Army Air Field in 1947. The X-1-2 flew until October 23, 1951, completing 74 glide and powered flights with nine different pilots. The aircraft has white paint and the NACA tail band. The black Xs are reference markings for tracking purposes. They were widely used on NACA aircraft in the early 1950s.

  17. Maintenance Production Management AFSC 2R1X1

    DTIC Science & Technology

    2001-05-01

    UNITED STATES AIR FORCE MAINTENANCE PRODUCTION MANAGEMENT AFSC 2R1X1 OSSN 2435 MAY 2001 OCCUPATIONAL ANALYSIS PROGRAM AIR FORCE OCCUPATIONAL...United States Air Force Occupational Survey Report Maintenance Production Management AFSC 2R1X1-OSSN 2435 Contract or Grant Number Program Element...INTENTIONALLY LEFT BLANK vii PREFACE This report presents the results of an Air Force Occupational Survey of the Maintenance Production Management career ladder

  18. A parallax distance to the microquasar GRS 1915+105 and a revised estimate of its black hole mass

    SciTech Connect

    Reid, M. J.; McClintock, J. E.; Steiner, J. F.; Narayan, R.; Steeghs, D.; Remillard, R. A.; Dhawan, V.

    2014-11-20

    Using the Very Long Baseline Array, we have measured a trigonometric parallax for the microquasar GRS 1915+105, which contains a black hole and a K-giant companion. This yields a direct distance estimate of 8.6{sub −1.6}{sup +2.0} kpc and a revised estimate for the mass of the black hole of 12.4{sub −1.8}{sup +2.0} M {sub ☉}. GRS 1915+105 is at about the same distance as some H II regions and water masers associated with high-mass star formation in the Sagittarius spiral arm of the Galaxy. The absolute proper motion of GRS 1915+105 is –3.19 ± 0.03 mas yr{sup –1} and –6.24 ± 0.05 mas yr{sup –1} toward the east and north, respectively, which corresponds to a modest peculiar speed of 22 ± 24 km s{sup –1} at the parallax distance, suggesting that the binary did not receive a large velocity kick when the black hole formed. On one observational epoch, GRS 1915+105 displayed superluminal motion along the direction of its approaching jet. Considering previous observations of jet motions, the jet in GRS 1915+105 can be modeled with a jet inclination to the line of sight of 60° ± 5° and a variable flow speed between 0.65c and 0.81c, which possibly indicates deceleration of the jet at distances from the black hole ≳ 2000 AU. Finally, using our measurements of distance and estimates of black hole mass and inclination, we provisionally confirm our earlier result that the black hole is spinning very rapidly.

  19. X-1A in flight with flight data superimposed

    NASA Technical Reports Server (NTRS)

    1953-01-01

    This photo of the X-1A includes graphs of the flight data from Maj. Charles E. Yeager's Mach 2.44 flight on December 12, 1953. (This was only a few days short of the 50th anniversary of the Wright brothers' first powered flight.) After reaching Mach 2.44, then the highest speed ever reached by a piloted aircraft, the X-1A tumbled completely out of control. The motions were so violent that Yeager cracked the plastic canopy with his helmet. He finally recovered from a inverted spin and landed on Rogers Dry Lakebed. Among the data shown are Mach number and altitude (the two top graphs). The speed and altitude changes due to the tumble are visible as jagged lines. The third graph from the bottom shows the G-forces on the airplane. During the tumble, these twice reached 8 Gs or 8 times the normal pull of gravity at sea level. (At these G forces, a 200-pound human would, in effect, weigh 1,600 pounds if a scale were placed under him in the direction of the force vector.) Producing these graphs was a slow, difficult process. The raw data from on-board instrumentation recorded on oscillograph film. Human computers then reduced the data and recorded it on data sheets, correcting for such factors as temperature and instrument errors. They used adding machines or slide rules for their calculations, pocket calculators being 20 years in the future. Three second generation Bell Aircraft Corporations X-1s were built, though four were requested. They were the X-1A (48-1384); X-1B (48-1385); X-1C (canceled and never built); X-1D (48-1386). These aircraft were similar to the X-1s, except they were five feet longer, had conventional canopies, and were powered by Reaction Motors, Inc. XLR11-RM-5 rocket engines. The RM-5, like the previous engines, had no throttle and was controlled by igniting one or more of the four thrust chambers at will. The original program outline called for the X-1A and X-1B to be used for dynamic stability and air loads investigations. The X-1D was to be used

  20. X-1A in flight with flight data superimposed

    NASA Technical Reports Server (NTRS)

    1953-01-01

    This photo of the X-1A includes graphs of the flight data from Maj. Charles E. Yeager's Mach 2.44 flight on December 12, 1953. (This was only a few days short of the 50th anniversary of the Wright brothers' first powered flight.) After reaching Mach 2.44, then the highest speed ever reached by a piloted aircraft, the X-1A tumbled completely out of control. The motions were so violent that Yeager cracked the plastic canopy with his helmet. He finally recovered from a inverted spin and landed on Rogers Dry Lakebed. Among the data shown are Mach number and altitude (the two top graphs). The speed and altitude changes due to the tumble are visible as jagged lines. The third graph from the bottom shows the G-forces on the airplane. During the tumble, these twice reached 8 Gs or 8 times the normal pull of gravity at sea level. (At these G forces, a 200-pound human would, in effect, weigh 1,600 pounds if a scale were placed under him in the direction of the force vector.) Producing these graphs was a slow, difficult process. The raw data from on-board instrumentation recorded on oscillograph film. Human computers then reduced the data and recorded it on data sheets, correcting for such factors as temperature and instrument errors. They used adding machines or slide rules for their calculations, pocket calculators being 20 years in the future. Three second generation Bell Aircraft Corporations X-1s were built, though four were requested. They were the X-1A (48-1384); X-1B (48-1385); X-1C (canceled and never built); X-1D (48-1386). These aircraft were similar to the X-1s, except they were five feet longer, had conventional canopies, and were powered by Reaction Motors, Inc. XLR11-RM-5 rocket engines. The RM-5, like the previous engines, had no throttle and was controlled by igniting one or more of the four thrust chambers at will. The original program outline called for the X-1A and X-1B to be used for dynamic stability and air loads investigations. The X-1D was to be used

  1. X-1E launch from B-50 mothership

    NASA Technical Reports Server (NTRS)

    1950-01-01

    Beginning in 1946, two XS-1 experimental research aircraft (later redesignated X-1s) conducted pioneering tests at Muroc Army Air Field (now Edwards Air Force Base) in California to obtain flight data on conditions in the transonic speed range. These early tests culminated on October 14, 1947, in the first piloted flight faster than Mach 1.0, the speed of sound. During November, 1947, the Air Force authorized studies that led to a contract (W-33-038-ac-20062) with Bell Aircraft to build four (later three) improved X-1 aircraft (the X-1C being cancelled). Designated X-1A (#48-1384), X-1B (#48-1385), and X-1D (#48-1386), the airplanes were ready by late 1950. The aircraft were about five feet longer and 2,500 lbs. heavier than the original X-craft planes. They used the 8-percent wing like the earlier X-craft. The D-model had a low-pressure turbo-pump and the B model was fitted with a prototype hydrogen peroxide reaction control system for later aircraft to use in exoatmospheric research flights. Access was through a lift-off canopy. The planes were finished in their bare metal color and white. The X-1D was ready first, but on what was intended to be its second flight (August 22, 1951) it was jettisoned and crashed at Muroc after an aerial explosion while still mated to its mother (B-50A [#46-006A]) ship. The long-delayed X-1 #3 airplane with the turbine pump was finally completed for the NACA in 1951. It made its first glide flight on July 20, 1951, with NACA pilot Joseph Cannon. Its second and final captive flight was on November 9, 1951. It was destroyed on the ground by an explosion and fire along with its B-50A mother ship while attempting to jettison fuel. The X-1A arrived at Muroc in January, 1953 and had its first powered flight on February 21, 1953. On December 8, 1953 with Yeager as pilot, the aircraft investigated high-speed stability and control issues. The X-1A was turned over to the NACA, but was lost to aerial explosion on August 8, 1955, shortly before

  2. X-1A in flight with flight data superimposed

    NASA Technical Reports Server (NTRS)

    1953-01-01

    This photo of the X-1A includes graphs of the flight data from Maj. Charles E. Yeager's Mach 2.44 flight on December 12, 1953. (This was only a few days short of the 50th anniversary of the Wright brothers' first powered flight.) After reaching Mach 2.44, then the highest speed ever reached by a piloted aircraft, the X-1A tumbled completely out of control. The motions were so violent that Yeager cracked the plastic canopy with his helmet. He finally recovered from a inverted spin and landed on Rogers Dry Lakebed. Among the data shown are Mach number and altitude (the two top graphs). The speed and altitude changes due to the tumble are visible as jagged lines. The third graph from the bottom shows the G-forces on the airplane. During the tumble, these twice reached 8 Gs or 8 times the normal pull of gravity at sea level. (At these G forces, a 200-pound human would, in effect, weigh 1,600 pounds if a scale were placed under him in the direction of the force vector.) Producing these graphs was a slow, difficult process. The raw data from on-board instrumentation recorded on oscillograph film. Human computers then reduced the data and recorded it on data sheets, correcting for such factors as temperature and instrument errors. They used adding machines or slide rules for their calculations, pocket calculators being 20 years in the future. Three second generation Bell Aircraft Corporations X-1s were built, though four were requested. They were the X-1A (48-1384); X-1B (48-1385); X-1C (canceled and never built); X-1D (48-1386). These aircraft were similar to the X-1s, except they were five feet longer, had conventional canopies, and were powered by Reaction Motors, Inc. XLR11-RM-5 rocket engines. The RM-5, like the previous engines, had no throttle and was controlled by igniting one or more of the four thrust chambers at will. The original program outline called for the X-1A and X-1B to be used for dynamic stability and air loads investigations. The X-1D was to be used

  3. Complete mitochondrial genome of Australian spiny lobster, Panulirus cygnus (George, 1962) (Crustacea: Decapoda: Palinuridae) from coast of Australia.

    PubMed

    Kim, Gyungryul; Yoon, Tae-Ho; Park, Won Gyu; Park, Jung Youn; Kang, Jung-Ha; Park, Hyun; Kim, Hyun Woo

    2016-11-01

    We characterized the total mitochondrial genome of Australian spiny lobster, Panulirus cygnus (George, 1962), which is found along the western coast of Australia. Total mitochondrial genome length of P. cygnus was 15 724 bp, in which 13 proteins, 2 ribosomal RNAs, 22 transfer RNAs, and a putative control region were encoded. Nine and four protein-coding genes are encoded on the H-strand and on the L-strand, respectively. According to the phylogenetic analysis, P. cygnus was most closely related to Panulirus japonicus among the compared six species belonging to Palinuridae. Although overall gene organization was the same, the putative control region (between SrRNA gene and tRNA(Ilel)) is least similar to one another among mitochondrial genomes from the compared six species belonging to Palinuridae.

  4. 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.

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

    NASA Astrophysics Data System (ADS)

    Alarie, Alexandre

    2016-06-01

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

  6. 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.

  7. 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.

  8. 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.

  9. Very-High-Energy Astrophysical Processes in the Cygnus Region of the Milky Way

    NASA Astrophysics Data System (ADS)

    Popkow, Alexis G.

    2017-05-01

    Very-high-energy (VHE) gamma-ray astronomy can provide insight in to the origin of cosmic rays. The Cygnus arm of the Galaxy is a well studied region and has been shown to have active sources of particle acceleration. VERITAS (Very Energetic Radiation Imaging Telescope Array System) is an array of four 12 meter diameter imaging atmospheric Cherenkov telescopes located at the Fred Lawrence Whipple Observatory in southern Arizona. From 2007 through 2012 VERITAS observed the Cygnus region for nearly 300 hours from 67° to 82° in Galactic longitude and from -1° to 4° in Galactic latitude. The survey and followup observations detected four sources: VER J2031+415, VER J2019+407, VER J2016+317, and VER J2019+368. The Fermi Large Area Telescope (Fermi-LAT) is a satellite gamma-ray telescope operating in the high-energy gamma-ray regime. The emission detected by the Fermi-LAT can provide insight into the nature of these sources and guide targeted followup observations in the region. We have reanalyzed the VERITAS data with updated VERITAS analysis and completed an analysis of over seven years of Fermi-LAT data in the region. We have discovered Fermi-LAT emission associated with VER J2031+415 strengthening its interpretation as a pulsar wind nebula, the SNR nature of VER J2019+407 has been confirmed by this study, and VER J2016+317 has been confirmed to be associated with the pulsar wind nebula CTB 87 rather than with a blazar source located at the same position. The Cygnus region is observed to be a particularly bright region of the Galaxy with both very-high-energy and high-energy gamma-ray experiments. These results motivate continued study of the region with VERITAS, as well as with current and future experiments such as HAWC and CTA.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  11. 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.

  12. 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.

  13. Further joint X-ray, infrared and radio observations of Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Mason, K. O.; Becklin, E. E.; Blankenship, L.; Brown, R. L.; Elias, J.; Hjellming, R. M.; Matthews, K.; Murdin, P. G.; Neugebauer, G.; Sanford, P. W.

    1975-01-01

    Observations of Cygnus X-3 were carried out at 2.5 - 7.5 keV, 2.2 micron, 8.1 GHz and 2.7 GHz over a two week period. The X-ray data show the periodic structure which is typical of Cyg X-3. At times the X-ray and infrared measurements show very similar periodic structure, both in phase and shape, while at other times the infrared data show no periodic variability. The radio fluxes were usually low during the period of observation; both the daily average radio flux levels and spectral index remained nearly constant.

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

    PubMed

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

    1998-03-20

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

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

    SciTech Connect

    Shoup, A.L.

    1993-01-01

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

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

    SciTech Connect

    Shoup, A.L.; The CYGNUS Collaboration

    1993-05-01

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

  17. Respiratory tract infection caused by Mycobacterium bovis in a black swan (Cygnus atratus).

    PubMed

    Sánchez, F D; Yela, I J; Alfonseca, E; Campuzano, J; Morales, E; Aguilar, C

    2016-01-01

    A 3-year-old male black swan (Cygnus atratus), belonging to a private collection, died suddenly and was subjected to post mortem examination. At necropsy, caseous exudate was observed in the lungs and air sacs; granulomatous lesions characterized by epithelioid macrophages and abundant mycobacteria were observed microscopically. Avian tuberculosis associated with Mycobacterium bovis was confirmed by bacteriologic isolation, biochemical tests and molecular methods. The organism was identified as spoligotype SB0140, which is frequently found in cattle and people in North America. In this case, interspecies transmission could have been the source of infection because the swan cohabited with cattle.

  18. Resolving the iron K line in Cygnus X-2 - An observation with BBXRT

    NASA Technical Reports Server (NTRS)

    Smale, A. P.; Done, C.; Mushotzky, R. F.; Weaver, K. A.; Serlemitsos, P. J.; Marshall, F. E.; Petre, R.; Jahoda, K. M.; Boldt, E. A.; Swank, J. H.

    1993-01-01

    The Astro-1 Space Shuttle payload's Broad Band X-ray telescope has been used to obtain high-quality, moderate-resolution spectroscopy of Cygnus X-2 which allow the resolving of the physical width of the 6.7 keV Fe K-alpha feature with a factor-of-4 energy resolution improvement over past experiments. Three possible sites are noted for the Fe K-alpha emission: the accretion disk, its corona, and the source itself. It is judged that reflection from the accretion disk can generate a line of the observed energy, width, and equivalent width, provided that the disk surface is highly ionized.

  19. "What's on Board" Science Briefing for Cygnus Orbital ATK OA-6

    NASA Image and Video Library

    2016-03-21

    In the Kennedy Space Center’s Press Site auditorium, members of the media participate in a briefing on science research and technology work planned for the International Space Station, or ISS. NASA is preparing for the launch of a Cygnus spacecraft on the Orbital ATK CRS-6 commercial resupply services mission to the ISS. From left are: Pete Hasbrook, NASA associate program scientist for the ISS Program at the Johnson Space Center in Houston, and Dr. Michael Roberts, deputy chief scientist for the Center for the Advancement for Science in Space, or CASIS.

  20. Thermal and Non-thermal emission in the Jets and Lobes of Cygnus A

    NASA Astrophysics Data System (ADS)

    De Vries, Martijn; Wise, Michael; Huppenkothen, Daniela; Nulsen, Paul; Snios, Bradford; Hardcastle, Martin

    2017-08-01

    We present a spatially-resolved, spectral analysis aimed at detecting and characterizing the non-thermal X-ray emission from the jets and lobes in the powerful radio galaxy Cygnus A based on a new, deep 1 Msec Chandra exposure. These jets and lobes are believed to be a primary means by which energy liberated by accretion onto the central supermassive black hole is transported into the outer galaxy and are integral to understanding the mechanisms that drive AGN feedback. Despite being well-studied over the years, we still do not understand how this energy is transported, the connection between the X-ray and radio structures, and the underlying emission mechanisms that produce them. The X-ray jets in Cygnus A show a clear misalignment with the radio and it has been proposed that they are either inverse Compton-emitting relics or a separate electron population emitting X-ray synchrotron emission. Previous X-ray studies of the jets and lobes have been unsuccessful in distinguishing between these possibilities largely due to the difficulty of separating any non-thermal components from thermal emission in the surrounding hot ICM at CCD spectral resolutions.In this presentation, we report on a new statistical analysis using MCMC sampling and Bayesian model selection to characterize the X-ray emission in the jets and lobes of Cygnus A. The model includes a mixture of thermal ICM emission and distinct non-thermal components from both the eastern and western jets and lobes. Our analysis clearly favors the presence of non-thermal emission and we find a distinct asymmetry with the western lobe roughly 20% fainter and with a much steeper photon index. Combining existing radio data with our X-ray fluxes and photon indices, we determine the energy densities and pressures for both synchrotron and inverse Compton (IC) emission models. For the IC model, we derive energy densities in the lobes consistent with the external pressure; however, both the eastern and western jets would be

  1. 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

  2. Preconceptual design requirements for the X-1 Advanced Radiation Source

    SciTech Connect

    Rochau, G.E.; Hands, J.A.; Raglin, P.S.; Ramirez, J.J.; Goldstein, S.A.; Cereghino, S.J.; MacLeod, G.

    1998-09-01

    The X-1 Advanced Radiation Source represents the next step in providing the US Department of Energy`s Stockpile Stewardship Program with the high-energy, large volume, laboratory x-ray source for the Radiation Effects Science and Simulation, Inertial Confinement Fusion, and Weapon Physics Programs. Advances in fast pulsed power technology and in z-pinch hohlraums on Sandia National Laboratories` Z Accelerator provide sufficient basis for pursuing the development of X-1. The X-1 plan follows a strategy based on scaling the 2 MJ x-ray output on Z via a 3-fold increase in z-pinch load current. The large volume (>5 cm{sup 3}), high temperature (>150 eV), temporally long (>10 ns) hohlraums are unique outside of underground nuclear weapon testing. Analytical scaling arguments and hydrodynamic simulations indicate that these hohlraums at temperatures of 230--300 eV will ignite thermonuclear fuel and drive the reaction to a yield of 200 to 1,000 MJ in the laboratory. X-1 will provide the high-fidelity experimental capability to certify the survivability and performance of non-nuclear weapon components in hostile radiation environments. Non-ignition sources will provide cold x-ray environments (<15 keV), and high yield fusion burn sources will provide high fidelity warm x-ray environments (15 keV--80 keV).

  3. UBV photometry of Cyg X-1 from 1996 to 2003

    NASA Astrophysics Data System (ADS)

    Voloshina, I. B.; Lyuty, V.

    2004-07-01

    The preliminary results of analysis of $UBV$-photometry of the black hole candidate Cyg X-1 in primary minimum are presented. These observations were carried out with the main goal of studying in detail the variability that was detected by Lyuty in 1985 in the optical light curve of this system near orbital phase 0.00.

  4. Recurrent X-ray outbursts from Aquila X-1

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    Aquila X-1 observations by the All Sky Monitor on Ariel 5 are presented. Data is compared with that obtained by rocket survey, and by the Uhuru, OSO 7, and OAO 3 satellites. The variability of brightness is discussed as a connection between dwarf novae and long term transient X ray sources.

  5. Herschel observations of Circinus X-1 during outburst and quiescence

    SciTech Connect

    Harrison, Thomas E.; Gelino, Dawn M.; Buxton, Michelle; Fost, Tyler E-mail: dawn@ipac.caltech.edu E-mail: tyler.fost@gmail.com

    2014-07-01

    We have used the Photodetector Array Camera and Spectrometer and Spectral and Photometric Imaging REceiver instruments on the Herschel Space Observatory to observe Cir X-1 both in and out of outburst. We detected Cir X-1 during outburst at 70 μm. Unfortunately, a cold background source dominates Cir X-1 at longer wavelengths. We have assembled optical and infrared (IR) data for Cir X-1 to model its spectral energy distribution (SED) in both quiescence and outburst and find that in both states it is consistent with a heavily reddened, 10,000 K blackbody. We believe this behavior is completely consistent with previous suggestions that these outbursts are due to accretion disk events, not unlike those of dwarf novae. To explore the behavior of other low-mass X-ray binaries with reported synchrotron jets, we have extracted and/or compiled optical and near- and mid-IR data sets for five such systems to construct their SEDs. The Z-source GX 349+2 and the black hole system GRS 1915+105 have strong and variable mid-IR excesses that suggest synchrotron emission. The other Z-sources have rather weak (or no) IR excesses that can be explained as reddened blackbody spectra with the addition of either synchrotron or bremsstrahlung components.

  6. Response of the middle atmosphere to Sco X-1

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.; Barcus, J. R.; Mitchell, J. D.

    1985-01-01

    On the night of Mar. 9, 1983 (UT) at Punta Lobos Launch Site, Peru (12.5 deg S, 76.8 deg W, magnetic dip -0.7 deg), a sequence of sounding rockets was flown to study the electrical structure of the equatorial middle atmosphere and to evaluate perturbations on this environment induced by the X-ray star Sco X-1. The rocket series was anchored by two Nike Orion payloads (31.032 and 31.033) which were launched at 0327 and 0857 UT, near Sco X-1 star-rise and after it had attained an elevation angle of 70 deg E. An enhanced flux of X-rays was observed on the second Nike Orion flight (31.033). This increase is directly attributed to Sco X-1, both from the spectral properties of the measured X-ray distribution and by spatial information acquired from a spinning X-ray detector during the upleg portion of the 31.033 flight. Simultaneously, a growth in ion conductivity and density was seen to occur in the lower mesosphere between 60 and 80 km on the second flight, specifically in the region of maximum energy deposition by the Sco X-1 X-rays. The results imply the presence of a significant number of ionized heavy constituents within the lower mesosphere, with masses possibly in the submacroscopoic range.

  7. Wind dynamics in SMC X-1. 1: Hydrodynamic simulation

    NASA Technical Reports Server (NTRS)

    Blondin, John M.; Woo, Jonathan W.

    1995-01-01

    We present a three-dimensional hydrodynamic simulation of the disrupted stellar wind in the high-mass X-ray binary system SMC X-1. The three dominant processes that determine the geometry of the wind in high X-ray luminosity systems such as SMC X-1 are the X-ray suppression of the stellar wind from the X-ray irradiated face of the primary star, the focusing of the radiatively driven wind in the X-ray shadow by the effects of stellar rotation, and the rapid X-ray heating of gas in the vicinity of the X-ray source, including the X-ray illuminated surface of the primary star. The resulting distribution of circumstellar gas provides a successful explanation for the asymmetric, extended eclipse transitions and the intensity of the deep eclipse X-ray emission in SMC X-1, as well as a possible explanation for the X-ray dips seen near superior conjunction of the X-ray source in Cyg X-1.

  8. Sunspot 1520 Releases Strong (X1.4) Solar Flare

    NASA Image and Video Library

    This movie shows the sun July 10-12, ending with the X1.4 class flare on July 12, 2012. It was captured by NASA’s Solar Dynamics Observatory in the 131 Angstrom wavelength - a wavelength that is...

  9. Discovery of a Luminous Radio Transient 460 pc from the Central Supermassive Black Hole in Cygnus A

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

    We report the appearance of a new radio source at a projected offset of 460 pc from the nucleus of Cygnus A. The flux density of the source (which we designate Cygnus A-2) rose from an upper limit of <0.5 mJy in 1989 to 4 mJy in 2016 (ν = 8.5 GHz), but is currently not varying by more than a few percent per year. The radio luminosity of the source is comparable to the most luminous known supernovae, it is compact in Very Long Baseline Array observations down to a scale of 4 pc, and it is coincident with a near-infrared point source seen in pre-existing adaptive optics and HST observations. The most likely interpretation of this source is that it represents a secondary supermassive black hole in a close orbit around the Cygnus A primary, though an exotic supernova model cannot be ruled out. The gravitational influence of a secondary SMBH at this location may have played an important role in triggering the rapid accretion that has powered the Cygnus A radio jet over the past 107 years.

  10. Visual Observation and Measurements of 33 so far Unconfirmed Tycho Double Stars in Cygnus with 2 Arcseconds Separation

    NASA Astrophysics Data System (ADS)

    Knapp, Wilfried

    2017-04-01

    As already reported (Knapp and Gould 2016), most Tycho Double Star objects in the WDS catalog are unconfirmed. From the huge number of in total nearly 1000 TDS/TDT objects in the Cygnus constellation, all unconfirmed pairs (per beginning of 2016) listed with 2" separation were visually observed and measured based on CCD images.

  11. 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.

  12. 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.

  13. Evidence of high-frequency/small-scale turbulence in the Cygnus region and anomalous Faraday rotation

    NASA Astrophysics Data System (ADS)

    Medvedev, Mikhail V.

    2017-01-01

    Faraday effect - a common and useful probe of cosmic magnetic fields - is the result of magnetically-induced birefringence in plasmas causing rotation of the polarization plane of a linearly polarized electromagnetic wave. Classically, the rotation angle scales with the wavelength as Δϕ =RMλ2 , where RM is the rotation measure. Although a typical RM in the Milky Way is of the order of a few hundred to a few thousand, a famous Cygnus region shows anomalously small, even negative rotation measures. Moreover, Faraday rotation measurements seem to be inconsistent with the standard λ2-law. We argue that fast micro-turbulence can cause this anomaly. We demonstrate that electromagnetic high-frequency and/or small-scale fluctuations can lead to effective plasma collisionality by scattering electrons over pitch-angle. We show that such quasi-collisionality radically alters Faraday rotation and other radiative transport properties, e.g., absorption, transmission and reflection. Thus, we explain the Cygnus puzzle by anomalous Faraday rotation in a thin ``blanket'' of highly turbulent plasma at the front of an interstellar bubble/shock. Supported by DOE grant DE-SC0016368.

  14. Hard X-ray Flux from Low-Mass Stars in the Cygnus OB2 Association

    NASA Astrophysics Data System (ADS)

    Caramazza, M.; Drake, J. J.; Micela, G.; Flaccomio, E.

    2009-05-01

    We investigate the X-ray emission in the 20-40 keV band expected from the flaring low-mass stellar population in Cygnus OB2 assuming that the observed soft X-ray emission is due to a superposition of flares and that the ratio of hard X-ray to soft X-ray emission is described by a scaling found for solar flares by Isola and co-workers. We estimate a low-mass stellar hard X-ray flux in the 20-40 keV band in the range ~7×1031-7×1033 erg/s and speculate the limit of this values. Hard X-ray emission could lie at a level not much below the current observed flux upper limits for Cygnus OB2. Simbol-X, with its broad energy band (10-100 keV) and its sensitivity should be able to detect this emission and would provide insights into the hard X-ray production of flares on pre-main sequence stars.

  15. 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.

    2016-12-01

    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.

  16. 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.

  17. Chandra-HETGS Observations of LMC X-1

    NASA Astrophysics Data System (ADS)

    Nowak, Michael

    2014-11-01

    The High Mass X-ray Binary, Black Hole Candidate (BHC) system LMC X-1 is among those that has been claimed to exhibit evidence for near maximal spin. However, compared to other systems, LMC X-1 is rather unusual in that it never shows evidence for ever reaching a "stable" minimum effective area. Here we discuss a series of Chandra-High Energy Transmission Gratings observations that cover a number of different orbital phases. We find spectroscopic evidence for emission from the high mass companion's wind. Additionally, we explore whether there is orbital phase-dependent absorption by this wind, as has been previously suggested. Finally, we use Comptonization models to describe the continuum spectrum, and discuss those aspects of the fits that are driving the suggestion for maximal spin.

  18. Particle Injection in the Cir X-1 radio outbursts

    NASA Technical Reports Server (NTRS)

    Sanchez, J. G.; Paredes, J. M.

    1996-01-01

    A particle injection model has been applied to the radio outbursts of the X-ray binary Circinus X-1. The radio outbursts of this system have often been observed to exhibit a double peaked structure, i.e., with two apparent consecutive maxima. We show here that particle injection models can account for such observed behavior provided that a time variable particle injection rate is adopted.

  19. EVN detection of Aql X-1 in outburst

    NASA Astrophysics Data System (ADS)

    Tudose, V.; Paragi, Z.; Miller-Jones, J.; Garrett, M.; Fender, R.; Rushton, A.; Spencer, R.

    2009-11-01

    The X-ray binary Aql X-1 has been in outburst in the last few weeks (ATEL #2288, #2296, #2299, #2302, #2303). We observed the system on 2009 November 19 between 14:30-19:00 UT at 5 GHz with the European VLBI Network (EVN) using the e-VLBI technique. The participating radio telescopes were Effelsberg (1 Gbps), Medicina (896 Mbps), Onsala 25m (1 Gbps), Torun (1 Gbps), Westerbork (1 Gbps), Yebes (896 Mbps), and Cambridge (128 Mbps).

  20. Evidence of Circumstellar Matter Surrounding the Hercules X-1 System

    NASA Technical Reports Server (NTRS)

    Choi, C. S.; Dotani, T.; Nagase, F.; Makino, F.; Deeter, J. E.; Min, K. W.

    1994-01-01

    We analyze data from two eclipse ingresses of Her X-1 observed with Ginga on 1989 April 30 and May 19. These observations occur, respectively, during the MAIN HIGH and SHORT HIGH states in the 35 day modulation of Her X-1 intensity. We find significant residual X-ray flux during eclipse, with a gradual decrease in flux following the occultation of the neutron star by the atmosphere of HZ Her. During the central part of the eclipse the count rate becomes nearly constant, at 0.5 mcrab in the energy range 1.7-36.8 keV. From a spec- tral analysis of the residual emission during the total eclipse of the central source in the MAIN MGH state, we determine the energy spectral index, alpha = 0.8, similar to that before eclipse. A remarkable feature of the eclipse spectrum is that it does not show a significant iron line feature in contrast to massive wind-fed pulsars, such as Vela X-1 and Cen X-3. From a timing analysis of the same eclipse data, we show that there are no pulses. These results imply that the emission comes from the scattering of continuum X-rays by material in a region considerably larger than the companion star. An extended accretion disk corona may be responsible for this scattering. However, partial eclipse of an extended accretion disk corona is insufficient to account for the count rates in mid-eclipse, when known parameters of the binary system are used. Based on the present results, we suggest that scattering occurs not only in the accretion disk corona but also in the circumstellar matter surrounding the system of Her X-1/HZ Her.

  1. Evidence of circumstellar matter surrounding the Hercules X-1 system

    NASA Technical Reports Server (NTRS)

    Choi, C. S.; Dotani, T.; Nagase, F.; Makino, F.; Deeter, J. E.; Min, K. W.

    1994-01-01

    We analyze data from two eclipse ingresses of Her X-1 observed with Ginga on 1989 April 30 and May 19. These observations occur, respectively, during the MAIN HIGH and SHORT HIGH states in the 35 day modulation of Her X-1 intensity. We find significant residual X-ray flux during eclipse, with a gradual decrease in flux following the occultation of the neutron star by the atmosphere of HZ Her. During the central part of the eclipse the count rate becomes nearly constant, at 0.5 mCrab in the energy range 1.7-36.8 keV. From a spectral analysis of the residual emission during the total eclipse of the central source in the MAIN HIGH state, we determine the energy spectral index, alpha = 0.8, similar to that before eclipse. A remarkable feature of the eclipse spectrum is that it does not show a significant iron line feature in contrast to massive wind-fed pulsars, such as Vela X-1 and Cen X-3. From a timing analysis of the same eclipse data, we show that there are no pulses. These results imply that the emission comes from the scattering of continuum X-rays by material in a region considerably larger than the companion star. An extended accretion disk corona may be responsible for this scattering. However, partial eclipse of an extended accretion disk corona may be responsible for this scattering. However, partial eclipse of an extended accretion disk corona is insufficient to account for the count rates in mid-eclipse, when known parameters of the binary system are used. Based on the present results, we suggest that scattering occurs not only in the accretion disk corona but also in the circumstellar matter surrounding the system of Her X-1/HZ Her.

  2. Evidence of circumstellar matter surrounding the Hercules X-1 system

    NASA Technical Reports Server (NTRS)

    Choi, C. S.; Dotani, T.; Nagase, F.; Makino, F.; Deeter, J. E.; Min, K. W.

    1994-01-01

    We analyze data from two eclipse ingresses of Her X-1 observed with Ginga on 1989 April 30 and May 19. These observations occur, respectively, during the MAIN HIGH and SHORT HIGH states in the 35 day modulation of Her X-1 intensity. We find significant residual X-ray flux during eclipse, with a gradual decrease in flux following the occultation of the neutron star by the atmosphere of HZ Her. During the central part of the eclipse the count rate becomes nearly constant, at 0.5 mCrab in the energy range 1.7-36.8 keV. From a spectral analysis of the residual emission during the total eclipse of the central source in the MAIN HIGH state, we determine the energy spectral index, alpha = 0.8, similar to that before eclipse. A remarkable feature of the eclipse spectrum is that it does not show a significant iron line feature in contrast to massive wind-fed pulsars, such as Vela X-1 and Cen X-3. From a timing analysis of the same eclipse data, we show that there are no pulses. These results imply that the emission comes from the scattering of continuum X-rays by material in a region considerably larger than the companion star. An extended accretion disk corona may be responsible for this scattering. However, partial eclipse of an extended accretion disk corona may be responsible for this scattering. However, partial eclipse of an extended accretion disk corona is insufficient to account for the count rates in mid-eclipse, when known parameters of the binary system are used. Based on the present results, we suggest that scattering occurs not only in the accretion disk corona but also in the circumstellar matter surrounding the system of Her X-1/HZ Her.

  3. Evidence of Circumstellar Matter Surrounding the Hercules X-1 System

    NASA Technical Reports Server (NTRS)

    Choi, C. S.; Dotani, T.; Nagase, F.; Makino, F.; Deeter, J. E.; Min, K. W.

    1994-01-01

    We analyze data from two eclipse ingresses of Her X-1 observed with Ginga on 1989 April 30 and May 19. These observations occur, respectively, during the MAIN HIGH and SHORT HIGH states in the 35 day modulation of Her X-1 intensity. We find significant residual X-ray flux during eclipse, with a gradual decrease in flux following the occultation of the neutron star by the atmosphere of HZ Her. During the central part of the eclipse the count rate becomes nearly constant, at 0.5 mcrab in the energy range 1.7-36.8 keV. From a spec- tral analysis of the residual emission during the total eclipse of the central source in the MAIN MGH state, we determine the energy spectral index, alpha = 0.8, similar to that before eclipse. A remarkable feature of the eclipse spectrum is that it does not show a significant iron line feature in contrast to massive wind-fed pulsars, such as Vela X-1 and Cen X-3. From a timing analysis of the same eclipse data, we show that there are no pulses. These results imply that the emission comes from the scattering of continuum X-rays by material in a region considerably larger than the companion star. An extended accretion disk corona may be responsible for this scattering. However, partial eclipse of an extended accretion disk corona is insufficient to account for the count rates in mid-eclipse, when known parameters of the binary system are used. Based on the present results, we suggest that scattering occurs not only in the accretion disk corona but also in the circumstellar matter surrounding the system of Her X-1/HZ Her.

  4. RXTE Observations of LMC X-1 and LMC X-3

    NASA Technical Reports Server (NTRS)

    Wilms, J.; Nowak, M. A.; Dove, J. B.; Pottschmidt, K.; Heindl, W. A.; Begelman, M. C.; Staubert, R.

    1998-01-01

    Of all known persistent stellar-mass black hole candidates, only LMC X-1 and LMC X-3 consistently show spectra that are dominated by a soft, thermal component. We present results from long (170 ksec) Rossi X-ray Timing Explorer (RXTE) observations of LMC X-1 and LMC X-3 made in 1996 December. The spectra can be described by a multicolor disk blackbody plus an additional high-energy power-law. Even though the spectra are very soft (Gamma approximately 2.5), RXTE detected a significant signal from LMC X-3 up to energies of 50 keV, the hardest energy at which the object was ever detected. Focusing on LMC X-3, we present results from the first year of an ongoing monitoring campaign with RXTE which started in 1997 January. We show that the appearance of the object changes considerably over its approximately 200d long cycle. This variability can either be explained by periodic changes in the mass transfer rate or by a precessing accretion disk analogous to Her X-1.

  5. RXTE Observations of LMC X-1 and LMC X-3

    NASA Technical Reports Server (NTRS)

    Wilms, J.; Nowak, M. A.; Dove, J. B.; Pottschmidt, K.; Heindl, W. A.; Begelman, M. C.; Staubert, R.

    1999-01-01

    Of all known persistent stellar-mass black hole candidates, only LMC X-1 and LMC X-3 consistently show spectra that are dominated by a soft, thermal component. We present results from long (170 ksec) Rossi X-ray Timing Explorer (RXTE) observations of LMC X-1 and LMC X-3 made in 1996 December. The spectra can be described by a multicolor disk blackbody plus an additional high-energy power-law. Even though the spectra are very soft (Gamma approximately 2.5), RXTE detected a significant signal from LMC X-3 up to energies of 50 keV, the hardest energy at which the object was ever detected. Focusing on LMC X-3 , we present results from the first year of an ongoing monitoring campaign with RXTE which started in 1997 January. We show that the appearance of the object changes considerably over its approximately 200 d long cycle. This variability can either be explained by periodic changes in the mass transfer rate or by a precessing accretion disk analogous to Her X-1.

  6. Scanning Tunneling Microscopy of SILICON(100) 2 X 1

    NASA Astrophysics Data System (ADS)

    Hubacek, Jerome S.

    1992-01-01

    The Si(100) 2 x 1 surface, a technologically important surface in microelectronics and silicon molecular beam epitaxy (MBE), has been studied with the scanning tunneling microscope (STM) to attempt to clear up the controversy that surrounds previous studies of this surface. To this end, an ultra-high vacuum (UHV) STM/surface science system has been designed and constructed to study semiconductor surfaces. Clean Si(100) 2 x 1 surfaces have been prepared and imaged with the STM. Atomic resolution images probing both the filled states and empty states indicate that the surface consists of statically buckled dimer rows. With electronic device dimensions shrinking to smaller and smaller sizes, the Si-SiO_2 interface is becoming increasingly important and, although it is the most popular interface used in the microelectronics industry, little is known about the initial stages of oxidation of the Si(100) surface. Scanning tunneling microscopy has been employed to examine Si(100) 2 x 1 surfaces exposed to molecular oxygen in UHV. Ordered rows of bright and dark spots, rotated 45^circ from the silicon dimer rows, appear in the STM images, suggesting that the Si(100)-SiO_2 interface may be explained with a beta -cristobalite(100) structure rotated by 45^ circ on the Si(100) surface.

  7. Discovery of orbital decay in SMC X-1

    NASA Technical Reports Server (NTRS)

    Levine, A.; Rappaport, S.; Boynton, P.; Deeter, J.; Nagase, F.

    1992-01-01

    The results are reported of three observations of the binary X ray pulsar SMC X-1 with the Ginga satellite. Timing analyses of the 0.71 s X ray pulsations yield Doppler delay curves which, in turn, provide the most accurate determination of the SMC X-1 orbital parameters available to date. The orbital phase of the 3.9 day orbit is determined in May 1987, Aug. 1988, and Aug. 1988 with accuracies of 11, 1, and 3.5 s, respectively. These phases are combined with two previous determinations of the orbital phase to yield the rate of change in the orbital period: P sub orb/P sub orb = (-3.34 + or - 0.023) x 10(exp -6)/yr. An interpretation of this measurement and the known decay rate for the orbit of Cen X-3 is made in the context of tidal evolution. Finally, a discussion is presented of the relation among the stellar evolution, orbital decay, and neutron star spinup time scales for the SMC X-1 system.

  8. VLA, PHOENIX and BATSE observations of an X1 flare

    NASA Astrophysics Data System (ADS)

    Willson, Robert F.; Aschwanden, Marcus J.; Benz, Arnold O.

    1992-01-01

    We present observations of an X1 flare detected simultaneously with the Very Large Array (VLA), the PHOENIX Digital Radio Spectrometer, and the Burst and Transient Source Experiment (BATSE) aboard the Gamma Ray Observatory (GRO). The VLA was used to produce snapshot maps of the impulsive burst emission in the higher corona on timescales of 1.7 seconds at both 20 and 01 cm. Our results indicate electron acceleration several minutes before the onset of the hard X-ray burst detected by BATSE. Comparisons with high spectral and spatial observations by PHOENIX reveal a variety of radio bursts at 20 cm, such as type III bursts, intermediate drift bursts, and quasi-periodic pulsations during different stages of the X1 flare. From the drift rates of these radio bursts we derive information on local density scale heights, the speed of radio exciters, and the local magnetic field. Radio emission at 90 cm shows a type IV burst moving outward with a constant velocity of 240 km/sec. The described X1 flare is unique in the sense that it appeared at the east limb (N06/E88 providing the most accurate information on the vertical structure of different flare tracers visible in radio wavelengths.

  9. VLA, PHOENIX, and BATSE observations of an X1 flare

    NASA Astrophysics Data System (ADS)

    Willson, Robert F.; Aschwanden, Markus J.; Benz, Arnold O.

    1992-02-01

    We present observations of an X1 flare (18 Jul. 1991) detected simultaneously with the Very Large Array (VLA), the PHOENIX Digital Radio Spectrometer and the Burst and Transient Source Experiment (BATSE) aboard the Gamma Ray Observatory (GRO). The VLA was used to produce snapshot maps of the impulsive acceleration in the higher corona several minutes before the onset of the hard x ray burst detected by BATSE. Comparisons with high spectral and temporal observations by PHOENIX reveal a variety of radio bursts at 20 cm, such as type 3 bursts, intermediate drift bursts, and quasi-periodic pulsations during different stages of the X1 flare. From the drift rates of these radio bursts we derive information on local density scale heights, the speed of radio exciters, and the local magnetic field. Radio emission at 90 cm shows a type 4 burst moving outward with a constant velocity of 240 km/s. The described X1 flare is unique in the sense that it appeared at the east limb (N06/E88), providing the most accurate information on the vertical structure of different flare tracers visible in radio wavelengths.

  10. External Shock Model for the Large-Scale, Relativistic X-Ray Jets from the Microquasar XTE J1550-564

    NASA Astrophysics Data System (ADS)

    Wang, X. Y.; Dai, Z. G.; Lu, T.

    2003-07-01

    Large-scale, decelerating, relativistic X-ray jets due to material ejected from the black-hole candidate X-ray transient and microquasar XTE J1550-564 have been recently discovered with Chandra by Corbel and coworkers. We find that the dynamical evolution of the eastern jet at the late time is consistent with the well-known Sedov evolutionary phase. A transrelativistic external shock dynamic model by analogy with the evolution of gamma-ray burst remnants is shown to be able to fit the observation data reasonably well. The inferred interstellar medium density around the source is well below the canonical value nISM~1cm-3. We find that the emission from the continuously shocked interstellar medium (forward shock region) decays too slowly to be a viable mechanism for the eastern X-ray jet. However, the rapidly fading X-ray emission can be interpreted as synchrotron radiation from the nonthermal electrons in the adiabatically expanding ejecta. These electrons were accelerated by the reverse shock (moving back into the ejecta), which becomes important when the inertia of the swept external matter leads to an appreciable slowing down of the original ejecta. To ensure the dominance of the emission from the shocked ejecta over that from the forward shock region during the period of the observations, the magnetic field and electron energy fractions in the forward shock region must be far below equipartition. Future continuous, follow-up multiwavelength observations of new ejection events from microquasars up to the significant deceleration phase should provide more valuable insight into the nature of the interaction between the jets and external medium.

  11. Discovery of a 7 mHz X-Ray Quasi-Periodic Oscillation from the Most Massive Stellar-Mass Black Hole IC 10 X-1

    NASA Technical Reports Server (NTRS)

    Pasham, Dheeraj R.; Strohmayer, Tod E.; Mushotzky, Richard F.

    2013-01-01

    We report the discovery with XMM-Newton of an approx.. = 7 mHz X-ray (0.3-10.0 keV) quasi-periodic oscillation (QPO) from the eclipsing, high-inclination black hole binary IC 10 X-1. The QPO is significant at >4.33 sigma confidence level and has a fractional amplitude (% rms) and a quality factor, Q is identical with nu/delta nu, of approx. = 11 and 4, respectively. The overall X-ray (0.3-10.0 keV) power spectrum in the frequency range 0.0001-0.1 Hz can be described by a power-law with an index of approx. = -2, and a QPO at 7 mHz. At frequencies approx. > 0.02 Hz there is no evidence for significant variability. The fractional amplitude (rms) of the QPO is roughly energy-independent in the energy range of 0.3-1.5 keV. Above 1.5 keV the low signal-to-noise ratio of the data does not allow us to detect the QPO. By directly comparing these properties with the wide range of QPOs currently known from accreting black hole and neutron stars, we suggest that the 7 mHz QPO of IC 10 X-1 may be linked to one of the following three categories of QPOs: (1) the "heartbeat" mHz QPOs of the black hole sources GRS 1915+105 and IGR J17091-3624, or (2) the 0.6-2.4 Hz "dipper QPOs" of high-inclination neutron star systems, or (3) the mHz QPOs of Cygnus X-3.

  12. DISCOVERY OF A 7 mHz X-RAY QUASI-PERIODIC OSCILLATION FROM THE MOST MASSIVE STELLAR-MASS BLACK HOLE IC 10 X-1

    SciTech Connect

    Pasham, Dheeraj R.; Mushotzky, Richard F.; Strohmayer, Tod E. E-mail: richard@astro.umd.edu

    2013-07-10

    We report the discovery with XMM-Newton of an Almost-Equal-To 7 mHz X-ray (0.3-10.0 keV) quasi-periodic oscillation (QPO) from the eclipsing, high-inclination black hole binary IC 10 X-1. The QPO is significant at >4.33{sigma} confidence level and has a fractional amplitude (% rms) and a quality factor, Q {identical_to} {nu}/{Delta}{nu}, of Almost-Equal-To 11 and 4, respectively. The overall X-ray (0.3-10.0 keV) power spectrum in the frequency range 0.0001-0.1 Hz can be described by a power-law with an index of Almost-Equal-To - 2, and a QPO at 7 mHz. At frequencies {approx}>0.02 Hz there is no evidence for significant variability. The fractional amplitude (rms) of the QPO is roughly energy-independent in the energy range of 0.3-1.5 keV. Above 1.5 keV the low signal-to-noise ratio of the data does not allow us to detect the QPO. By directly comparing these properties with the wide range of QPOs currently known from accreting black hole and neutron stars, we suggest that the 7 mHz QPO of IC 10 X-1 may be linked to one of the following three categories of QPOs: (1) the 'heartbeat' mHz QPOs of the black hole sources GRS 1915+105 and IGR J17091-3624, or (2) the 0.6-2.4 Hz 'dipper QPOs' of high-inclination neutron star systems, or (3) the mHz QPOs of Cygnus X-3.

  13. Nucleophosmin Interacts with PIN2/TERF1-interacting Telomerase Inhibitor 1 (PinX1) and Attenuates the PinX1 Inhibition on Telomerase Activity

    PubMed Central

    Cheung, Derek Hang-Cheong; Ho, Sai-Tim; Lau, Kwok-Fai; Jin, Rui; Wang, Ya-Nan; Kung, Hsiang-Fu; Huang, Jun-Jian; Shaw, Pang-Chui

    2017-01-01

    Telomerase activation and telomere maintenance are critical for cellular immortalization and transformation. PIN2/TERF1-interacting telomerase inhibitor 1 (PinX1) is a telomerase regulator and the aberrant expression of PinX1 causes telomere shortening. Identifying PinX1-interacting proteins is important for understanding telomere maintenance. We found that PinX1 directly interacts with nucleophosmin (NPM), a protein that has been shown to positively correlate with telomerase activity. We further showed that PinX1 acts as a linker in the association between NPM and hTERT, the catalytic subunit of telomerase. Additionally, the recruitment of NPM by PinX1 to the telomerase complex could partially attenuate the PinX1-mediated inhibition on telomerase activity. Taken together, our data reveal a novel mechanism that regulates telomerase activation through the interaction between NPM, PinX1 and the telomerase complex. PMID:28255170

  14. NuSTAR observations of the powerful radio-galaxy Cygnus A

    DOE PAGES

    Reynolds, Christopher S.; Lohfink, Anne M.; Ogle, Patrick M.; ...

    2015-07-29

    Here, 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 tomore » $$\\gt 70$$ keV. In gross terms, the NuSTAR spectrum of the AGN has the form of a power law ($${\\rm{\\Gamma }}\\sim 1.6-1.7$$) absorbed by a neutral column density of $${N}_{{\\rm{H}}}\\sim 1.6\\times {10}^{23}\\;\\;{\\mathrm{cm}}^{-2}$$. 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 $${E}_{\\mathrm{cut}}\\gt 111$$ keV(90% confidence). Interestingly, the absorbed power law plus reflection model leaves residuals suggesting the absorption/emission from a fast ($$15,000-26,000\\;\\;\\mathrm{km}\\;\\;{{\\rm{s}}}^{-1}\\;$$), high column-density ($${N}_{W}\\gt 3\\times {10}^{23}\\;\\;{\\mathrm{cm}}^{-2}$$), highly ionized ($$\\xi \\sim 2500\\;\\mathrm{erg}\\;\\mathrm{cm}\\;{{\\rm{s}}}^{-1}$$) 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.« less

  15. NuSTAR observations of the powerful radio-galaxy Cygnus A

    SciTech Connect

    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

    2015-07-29

    Here, 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 (${\\rm{\\Gamma }}\\sim 1.6-1.7$) absorbed by a neutral column density of ${N}_{{\\rm{H}}}\\sim 1.6\\times {10}^{23}\\;\\;{\\mathrm{cm}}^{-2}$. 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 ${E}_{\\mathrm{cut}}\\gt 111$ keV(90% confidence). Interestingly, the absorbed power law plus reflection model leaves residuals suggesting the absorption/emission from a fast ($15,000-26,000\\;\\;\\mathrm{km}\\;\\;{{\\rm{s}}}^{-1}\\;$), high column-density (${N}_{W}\\gt 3\\times {10}^{23}\\;\\;{\\mathrm{cm}}^{-2}$), highly ionized ($\\xi \\sim 2500\\;\\mathrm{erg}\\;\\mathrm{cm}\\;{{\\rm{s}}}^{-1}$) 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.

  16. Radio non-detection of Aql X-1

    NASA Astrophysics Data System (ADS)

    Tudose, V.; Paragi, Z.; Altamirano, D.; Miller-Jones, J. C. A.; Garrett, M.; Fender, R.; Rushton, A.; Spencer, R.; Maitra, D.

    2010-10-01

    The neutron star X-ray binary Aql X-1 is on the decaying phase of a major outburst that peaked at optical and X-ray bands in mid-September (ATEL #2850, #2871, #2891, #2902). We observed the object at 5 GHz with the European VLBI Network (EVN) in the e-VLBI mode on 2010 October 4th between 18:20-22:09 UT. The participating stations were Cambridge, Effelsberg, Jodrell Bank (MkII), Hartebeesthoek, Medicina, Onsala, Torun, Westerbork and Yebes.

  17. Gene therapy outpaces haplo for SCID-X1.

    PubMed

    Kohn, Donald B

    2015-06-04

    In this issue of Blood, Touzot et al report that autologous gene therapy/hematopoietic stem cell transplantation (HSCT) for infants with X-linked severe combined immune deficiency (SCID-X1) lacking a matched sibling donor may have better outcomes than haploidentical (haplo) HSCT. Because gene therapy represents an autologous transplant, it obviates immune suppression before and after transplant, eliminates risks of graft versus host disease (GVHD), and, as the authors report, led to faster immunological reconstitution after transplant than did haplo transplant.

  18. X-1E Loaded in B-29 Mothership on Ramp

    NASA Technical Reports Server (NTRS)

    1955-01-01

    The Bell Aircraft Corporation X-1E airplane being loaded under the mothership, Boeing B-29. The X-planes had originally been lowered into a loading pit and the launch aircraft towed over the pit, where the rocket plane was hoisted by belly straps into the bomb bay. By the early 1950s a hydraulic lift had been installed on the ramp at the NACA High-Speed Flight Station to elevate the launch aircraft and then lower it over the rocket plane for mating.

  19. Confidence about line features in Her X-1 spectrum

    NASA Technical Reports Server (NTRS)

    Durouchoux, P.; Boclet, D.; Rocchia, R.

    1978-01-01

    A balloon borne X-ray telescope was flown Aire-surl'Adour, France to search for pulsation of the X-ray source HER X1. The source was measured for about 3500 s relative exposure larger than 0.75 and features were detected at 57.5 plus or minus 7.5 keV and 135 plus or minus 10 keV in the spectrum. Data were reanalyzed in terms of possibility of gain shift encoder. The very strong dependence of the line features on such a shift is discussed.

  20. 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.