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Your search keyword '"Wu, Jianfeng"' showing total 15 results
Start Over Author "Wu, Jianfeng" Journal monthly notices of the royal astronomical society
15 results on '"Wu, Jianfeng"'

4. Optical and ultraviolet monitoring of the black hole X-ray binary MAXI J1820+070/ASASSN-18ey for 18 months

Author

Sai, Hanna, primary, Wang, Xiaofeng, additional, Wu, Jianfeng, additional, Lin, Jie, additional, Feng, Hua, additional, Zhang, Tianmeng, additional, Li, Wenxiong, additional, Zhang, Jujia, additional, Mo, Jun, additional, Sun, Tianrui, additional, Ehgamberdiev, Shuhrat A, additional, Mirzaqulov, Davron, additional, Rui, Liming, additional, Lin, Weili, additional, Zhao, Xulin, additional, Lin, Han, additional, Zhang, Jicheng, additional, Zhang, Xinghan, additional, Zhao, Yong, additional, Li, Xue, additional, Xiang, Danfeng, additional, Wang, Lingzhi, additional, and Wu, Chengyuan, additional

Published
2021
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9. The Chandra Galactic Bulge Survey: optical catalogue and point-source counterparts to X-ray sources

Author

Wevers, T., primary, Hodgkin, S. T., additional, Jonker, P. G., additional, Bassa, C., additional, Nelemans, G., additional, van Grunsven, T., additional, Gonzalez-Solares, E. A., additional, Torres, M. A. P., additional, Heinke, C., additional, Steeghs, D., additional, Maccarone, T. J., additional, Britt, C., additional, Hynes, R. I., additional, Johnson, C., additional, and Wu, Jianfeng, additional

Published
2016
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11. Tomography of X-ray Nova Muscae 1991: evidence for ongoing mass transfer and stream–disc overflow★

Author

Peris, Charith S., primary, Vrtilek, Saeqa D., additional, Steiner, James F., additional, Vrtilek, Jan M., additional, Wu, Jianfeng, additional, McClintock, Jeffrey E., additional, Longa-Peña, Penelope, additional, Steeghs, Danny, additional, Callanan, Paul, additional, Ho, Luis C., additional, Orosz, Jerome A., additional, and Reynolds, Mark T., additional

Published
2015
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15. X-ray and multiwavelength insights into the inner structure of high-luminosity disc-like emitters.

Author

Luo, B., Brandt, W. N., Eracleous, M., Wu, Jian, Hall, P. B., Rafiee, A., Schneider, D. P., and Wu, Jianfeng

Subjects
WAVELENGTHS, X-rays, ACTIVE galactic nuclei, REDSHIFT, ACCRETION disks, ULTRAVIOLET spectra
Abstract

We present X-ray and multiwavelength studies of a sample of eight high-luminosity active galactic nuclei (AGN) with disc-like Hβ emission-line profiles selected from the Sloan Digital Sky Survey Data Release 7. These sources have higher redshift (z ≈ 0.6) than the majority of the known disc-like emitters, and they occupy a largely unexplored space in the luminosity–redshift plane. Seven sources have typical AGN X-ray spectra with power-law photon indices of Γ ≈ 1.4–2.0; two of them show some X-ray absorption (column density NH ≈ 1021–1022 cm−2 for neutral gas). The other source, J0850+4451, has only three hard X-ray photons detected and is probably heavily obscured (NH ≳ 3 × 1023 cm−2). This object is also identified as a low-ionization broad absorption line (BAL) quasar based on Mg ii λ2799 absorption; it is the first disc-like emitter reported that is also a BAL quasar. The infrared-to-ultraviolet (UV) spectral energy distributions (SEDs) of these eight sources are similar to the mean SEDs of typical quasars with a UV ‘bump’, suggestive of standard accretion discs radiating with high efficiency, which differs from low-luminosity disc-like emitters. Studies of the X-ray-to-optical power-law slope parameters (αOX) indicate that there is no significant excess X-ray emission in these high-luminosity disc-like emitters. Energy budget analysis suggests that for disc-like emitters in general, the inner disc must illuminate and ionize the outer disc efficiently (≈15 per cent of the nuclear ionizing radiation is required on average) via direct illumination and/or scattering. Warped accretion discs are probably needed for direct illumination to work in high-luminosity objects, as their geometrically thin inner discs decrease the amount of direct illumination possible for a flat disc. [ABSTRACT FROM AUTHOR]

Published
2013
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