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Shuping Yan – One of the best experts on this subject based on the ideXlab platform.

  • on the nature of the first transient z source xte j1701 462 its Accretion Disk structure neutron star magnetic field strength and hard tail
    The Astronomical Journal, 2011
    Co-Authors: Guoqiang Ding, Shuangnan Zhang, Na Wang, Shuping Yan
    Abstract:

    Using data from the Rossi X-Ray Timing Explorer, we investigate the spectral evolution along a “Z” track and a “v” track on the hardness-intensity diagrams of the first transient Z source XTE J1701-462. The spectral analyses suggest that the inner Disk radius depends on the mass Accretion rate, in agreement with the model prediction, R-in alpha (M) over dot(Disk)(2/7), for a radiation-pressure-dominated Accretion Disk interacting with the magnetosphere of a neutron star (NS). The changes in the Disk mass Accretion rate (M) over dot(Disk) are responsible for the evolution of the “Z” or “v” track. Radiation pressure thickens the Disk considerably and also produces significant outflows. The NS surface magnetic field strength, derived from the interaction between the magnetosphere and the radiation-pressure-dominated Accretion Disk, is similar to(1-3) x 10(9) G, which is possibly between normal atoll and Z sources. A significant hard tail is detected in the horizontal branches and we discuss several possible origins of the hard tail.

  • on the nature of the first transient z source xte j1701 462 its Accretion Disk structure neutron star magnetic field strength and hard tail
    arXiv: High Energy Astrophysical Phenomena, 2011
    Co-Authors: Guoqiang Ding, Shuangnan Zhang, Na Wang, Shuping Yan
    Abstract:

    Using the data from the Rossi X-Ray Timing Explorer satellite, we investigate the spectral evolution along a “Z” track and a “v” track on the hardness-intensity diagrams of the first transient Z source XTE J1701-462. The spectral analyses suggest that the inner Disk radius depends on the mass Accretion rate, in agreement with the model prediction, R_in \propto ((dM/dt)_Disk)^{2/7}, for a radiation pressure dominated Accretion Disk interacting with the magnetosphere of a neutron star (NS). The changes in the Disk mass Accretion rate (dM/dt)_Disk are responsible for the evolution of the “Z” or “v” track. The radiation pressure thickens the Disk considerably, and also produces significant outflows. The NS surface magnetic field strength, derived from the interaction between the magnetosphere and the radiation pressure dominated Accretion Disk, is ~(1–3)X10^9 G, which is possibly between normal atoll and Z sources. A significant hard tail is detected in the horizontal branches and we discuss several possible origins of the hard tail.

Guoqiang Ding – One of the best experts on this subject based on the ideXlab platform.

  • on the nature of the first transient z source xte j1701 462 its Accretion Disk structure neutron star magnetic field strength and hard tail
    The Astronomical Journal, 2011
    Co-Authors: Guoqiang Ding, Shuangnan Zhang, Na Wang, Shuping Yan
    Abstract:

    Using data from the Rossi X-Ray Timing Explorer, we investigate the spectral evolution along a “Z” track and a “v” track on the hardness-intensity diagrams of the first transient Z source XTE J1701-462. The spectral analyses suggest that the inner Disk radius depends on the mass Accretion rate, in agreement with the model prediction, R-in alpha (M) over dot(Disk)(2/7), for a radiation-pressure-dominated Accretion Disk interacting with the magnetosphere of a neutron star (NS). The changes in the Disk mass Accretion rate (M) over dot(Disk) are responsible for the evolution of the “Z” or “v” track. Radiation pressure thickens the Disk considerably and also produces significant outflows. The NS surface magnetic field strength, derived from the interaction between the magnetosphere and the radiation-pressure-dominated Accretion Disk, is similar to(1-3) x 10(9) G, which is possibly between normal atoll and Z sources. A significant hard tail is detected in the horizontal branches and we discuss several possible origins of the hard tail.

  • on the nature of the first transient z source xte j1701 462 its Accretion Disk structure neutron star magnetic field strength and hard tail
    arXiv: High Energy Astrophysical Phenomena, 2011
    Co-Authors: Guoqiang Ding, Shuangnan Zhang, Na Wang, Shuping Yan
    Abstract:

    Using the data from the Rossi X-Ray Timing Explorer satellite, we investigate the spectral evolution along a “Z” track and a “v” track on the hardness-intensity diagrams of the first transient Z source XTE J1701-462. The spectral analyses suggest that the inner Disk radius depends on the mass Accretion rate, in agreement with the model prediction, R_in \propto ((dM/dt)_Disk)^{2/7}, for a radiation pressure dominated Accretion Disk interacting with the magnetosphere of a neutron star (NS). The changes in the Disk mass Accretion rate (dM/dt)_Disk are responsible for the evolution of the “Z” or “v” track. The radiation pressure thickens the Disk considerably, and also produces significant outflows. The NS surface magnetic field strength, derived from the interaction between the magnetosphere and the radiation pressure dominated Accretion Disk, is ~(1–3)X10^9 G, which is possibly between normal atoll and Z sources. A significant hard tail is detected in the horizontal branches and we discuss several possible origins of the hard tail.

J E Reynolds – One of the best experts on this subject based on the ideXlab platform.

  • a warped Accretion Disk and wide angle outflow in the inner parsec of the circinus galaxy
    The Astrophysical Journal, 2003
    Co-Authors: L J Greenhill, R S Booth, S P Ellingsen, J R Herrnstein, D L Jauncey, P M Mcculloch, J M Moran, R P Norris, J E Reynolds
    Abstract:

    We present the first VLBI maps of H2O maser emission (λ1.3 cm) in the nucleus of the Circinus galaxy, constructed from data obtained with the Australia Telescope Long Baseline Array. The maser emission traces a warped, edge-on Accretion Disk between radii of 0.11 ± 0.02 and ~0.40 pc, as well as a wide-angle outflow that extends up to ~1 pc from the estimated Disk center. The Disk rotation is close to Keplerian (v ∝ r-0.5), the maximum detected rotation speed is 260 km s-1, and the inferred central mass is (1.7 ± 0.3) × 106 M☉. The outflowing masers are irregularly distributed above and below the Disk, with relative outflow velocities up to ~±160 km s-1, projected along the line of sight. The flow probably originates closer than 0.1 pc to the central engine, possibly in an inward extension of the Accretion Disk, although there is only weak evidence of rotation in the outward-moving material. We observe that the warp of the Disk appears to collimate the outflow and to fix the extent of the ionization cone observed on larger angular scales. This study provides the first direct evidence (i.e., through imaging) of dusty, high-density, molecular material in a nuclear outflow less than 1 pc from the central engine of a Seyfert galaxy, as well as the first graphic evidence that warped Accretion Disks can channel outflows and illumination patterns in active galactic nuclei. We speculate that the same arrangement, which in some ways obviates the need for a geometrically thick, dusty torus, may apply to other type 2 active galactic nuclei.

  • a warped Accretion Disk and wide angle outflow in the inner parsec of the circinus galaxy
    arXiv: Astrophysics, 2003
    Co-Authors: L J Greenhill, R S Booth, S P Ellingsen, J R Herrnstein, D L Jauncey, P M Mcculloch, J M Moran, R P Norris, J E Reynolds
    Abstract:

    We present the first VLBI maps of H2O maser emission (lambda 1.3cm) in the nucleus of the Circinus Galaxy, constructed from data obtained with the Australia Telescope Long Baseline Array. The maser emission traces a warped, edge-on Accretion Disk between radii of 0.11+/-0.02 and ~0.40 pc, as well as a wide-angle outflow that extends up to ~1 pc from the estimated Disk center. The Disk rotation is close to Keplerian (v varies as 1/sqrt(r)), the maximum detected rotation speed is 260 km/s, and the inferred central mass is 1.7+/-0.3 x 10^6 solar masses. The outflowing masers are irregularly distributed above and below the Disk, with relative outflow velocities up to ~+/-160 km/s, projected along the line of sight. The flow probably originates closer than 0.1 pc to the central engine, possibly in an inward extension of the Accretion Disk, though there is only weak evidence of rotation in the outward moving material. We observe that the warp of the Disk appears to collimate the outflow and to fix the extent of the ionization cone observed on larger angular scales. This study provides the first direct evidence (i.e., through imaging) of dusty, high-density, molecular material in a nuclear outflow <1 pc from the central engine of a Seyfert galaxy, as well as the first graphic evidence that warped Accretion Disks can channel outflows and illumination patterns in AGN. We speculate that the same arrangement, which in some ways obviates the need for a geometrically thick, dusty torus, may apply to other type-2 AGN.

J R Herrnstein – One of the best experts on this subject based on the ideXlab platform.

  • a warped Accretion Disk and wide angle outflow in the inner parsec of the circinus galaxy
    The Astrophysical Journal, 2003
    Co-Authors: L J Greenhill, R S Booth, S P Ellingsen, J R Herrnstein, D L Jauncey, P M Mcculloch, J M Moran, R P Norris, J E Reynolds
    Abstract:

    We present the first VLBI maps of H2O maser emission (λ1.3 cm) in the nucleus of the Circinus galaxy, constructed from data obtained with the Australia Telescope Long Baseline Array. The maser emission traces a warped, edge-on Accretion Disk between radii of 0.11 ± 0.02 and ~0.40 pc, as well as a wide-angle outflow that extends up to ~1 pc from the estimated Disk center. The Disk rotation is close to Keplerian (v ∝ r-0.5), the maximum detected rotation speed is 260 km s-1, and the inferred central mass is (1.7 ± 0.3) × 106 M☉. The outflowing masers are irregularly distributed above and below the Disk, with relative outflow velocities up to ~±160 km s-1, projected along the line of sight. The flow probably originates closer than 0.1 pc to the central engine, possibly in an inward extension of the Accretion Disk, although there is only weak evidence of rotation in the outward-moving material. We observe that the warp of the Disk appears to collimate the outflow and to fix the extent of the ionization cone observed on larger angular scales. This study provides the first direct evidence (i.e., through imaging) of dusty, high-density, molecular material in a nuclear outflow less than 1 pc from the central engine of a Seyfert galaxy, as well as the first graphic evidence that warped Accretion Disks can channel outflows and illumination patterns in active galactic nuclei. We speculate that the same arrangement, which in some ways obviates the need for a geometrically thick, dusty torus, may apply to other type 2 active galactic nuclei.

  • a warped Accretion Disk and wide angle outflow in the inner parsec of the circinus galaxy
    arXiv: Astrophysics, 2003
    Co-Authors: L J Greenhill, R S Booth, S P Ellingsen, J R Herrnstein, D L Jauncey, P M Mcculloch, J M Moran, R P Norris, J E Reynolds
    Abstract:

    We present the first VLBI maps of H2O maser emission (lambda 1.3cm) in the nucleus of the Circinus Galaxy, constructed from data obtained with the Australia Telescope Long Baseline Array. The maser emission traces a warped, edge-on Accretion Disk between radii of 0.11+/-0.02 and ~0.40 pc, as well as a wide-angle outflow that extends up to ~1 pc from the estimated Disk center. The Disk rotation is close to Keplerian (v varies as 1/sqrt(r)), the maximum detected rotation speed is 260 km/s, and the inferred central mass is 1.7+/-0.3 x 10^6 solar masses. The outflowing masers are irregularly distributed above and below the Disk, with relative outflow velocities up to ~+/-160 km/s, projected along the line of sight. The flow probably originates closer than 0.1 pc to the central engine, possibly in an inward extension of the Accretion Disk, though there is only weak evidence of rotation in the outward moving material. We observe that the warp of the Disk appears to collimate the outflow and to fix the extent of the ionization cone observed on larger angular scales. This study provides the first direct evidence (i.e., through imaging) of dusty, high-density, molecular material in a nuclear outflow <1 pc from the central engine of a Seyfert galaxy, as well as the first graphic evidence that warped Accretion Disks can channel outflows and illumination patterns in AGN. We speculate that the same arrangement, which in some ways obviates the need for a geometrically thick, dusty torus, may apply to other type-2 AGN.

Shuangnan Zhang – One of the best experts on this subject based on the ideXlab platform.

  • on the nature of the first transient z source xte j1701 462 its Accretion Disk structure neutron star magnetic field strength and hard tail
    The Astronomical Journal, 2011
    Co-Authors: Guoqiang Ding, Shuangnan Zhang, Na Wang, Shuping Yan
    Abstract:

    Using data from the Rossi X-Ray Timing Explorer, we investigate the spectral evolution along a “Z” track and a “v” track on the hardness-intensity diagrams of the first transient Z source XTE J1701-462. The spectral analyses suggest that the inner Disk radius depends on the mass Accretion rate, in agreement with the model prediction, R-in alpha (M) over dot(Disk)(2/7), for a radiation-pressure-dominated Accretion Disk interacting with the magnetosphere of a neutron star (NS). The changes in the Disk mass Accretion rate (M) over dot(Disk) are responsible for the evolution of the “Z” or “v” track. Radiation pressure thickens the Disk considerably and also produces significant outflows. The NS surface magnetic field strength, derived from the interaction between the magnetosphere and the radiation-pressure-dominated Accretion Disk, is similar to(1-3) x 10(9) G, which is possibly between normal atoll and Z sources. A significant hard tail is detected in the horizontal branches and we discuss several possible origins of the hard tail.

  • on the nature of the first transient z source xte j1701 462 its Accretion Disk structure neutron star magnetic field strength and hard tail
    arXiv: High Energy Astrophysical Phenomena, 2011
    Co-Authors: Guoqiang Ding, Shuangnan Zhang, Na Wang, Shuping Yan
    Abstract:

    Using the data from the Rossi X-Ray Timing Explorer satellite, we investigate the spectral evolution along a “Z” track and a “v” track on the hardness-intensity diagrams of the first transient Z source XTE J1701-462. The spectral analyses suggest that the inner Disk radius depends on the mass Accretion rate, in agreement with the model prediction, R_in \propto ((dM/dt)_Disk)^{2/7}, for a radiation pressure dominated Accretion Disk interacting with the magnetosphere of a neutron star (NS). The changes in the Disk mass Accretion rate (dM/dt)_Disk are responsible for the evolution of the “Z” or “v” track. The radiation pressure thickens the Disk considerably, and also produces significant outflows. The NS surface magnetic field strength, derived from the interaction between the magnetosphere and the radiation pressure dominated Accretion Disk, is ~(1–3)X10^9 G, which is possibly between normal atoll and Z sources. A significant hard tail is detected in the horizontal branches and we discuss several possible origins of the hard tail.