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748 results on '"Li, X. B."'

1. The bright black hole X-ray binary 4U 1543--47 during 2021 outburst: a thick accretion disk inflated by high luminosity

Author: Zhao, S. J., Tao, L., Li, P. P., Soria, R., Feng, H., Zhang, Y. X., Ma, R. C., Zhang, W. D., Qiao, E. L., Yin, Q. Q., Zhang, S. N., Zhang, L., Bu, Q. C., Ma, X., Huang, Y., Ge, M. Y., Li, X. B., Zhao, Q. C., Peng, J. Q., and Xiao, Y. X.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The black hole X-ray binary source 4U 1543--47 experienced a super-Eddington outburst in 2021, reaching a peak flux of up to $\sim1.96\times10^{-7}\rm erg\ \rm cm^{-2}\ \rm s^{-1}$ ($\sim 8.2$ Crab) in the 2--10\,keV band. Soon after the outburst began, it rapidly transitioned into the soft state. Our goal is to understand how the accretion disk structure deviates from a standard thin disk when the accretion rate is near Eddington. To do so, we analyzed spectra obtained from quasi-simultaneous observations conducted by the Hard X-ray Modulation Telescope (Insight-HXMT), the Nuclear Spectroscopic Telescope Array (NuSTAR), and the Neil Gehrels Swift Observatory (Swift). These spectra are well-fitted by a model comprising a disk, a weak corona, and a reflection component. We suggest that the reflection component is caused by disk self-irradiation, that is by photons emitted from the inner disk which return to the accretion disk surface, as their trajectories are bent by the strong gravity field. In this scenario, the best-fitting parameters imply that the reflected flux represents more than half of the total flux. Using general relativistic ray-tracing simulations, we show that this scenario is viable when the disk becomes geometrically thick, with a funnel-like shape, as the accretion rate is near or above the Eddington limit. In the specific case of 4U 1543--47, an angle $\gtrsim$ 45 deg between the disk surface and the equatorial plane can explain the required amount of self-irradiation., Comment: Accepted for publication in Astronomy and Astrophysics. 15 pages, 4 tables, 12 figures
Published: 2023
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2. Evidence of mini-jet emission in a large emission zone from a magnetically-dominated gamma-ray burst jet

Author: Yi, S. -X., Wang, C. -W., Shao, X. -Y., Moradi, R., Gao, H., Zhang, B., Xiong, S. -L., Zhang, S. -N., Tan, W. -J., Liu, J. -C., Xue, W. -C., Zhang, Y. -Q., Zheng, C., Wang, Y., Zhang, P., An, Z. -H., Cai, C., Feng, P. -Y., Gong, K., Guo, D. -Y., Huang, Y., Li, B., Li, X. -B., Li, X. -Q., Liu, X. -J., Liu, Y. -Q., Ma, X., Peng, W. -X., Qiao, R., Song, L. -M., Wang, J., Wang, P., Wen, X. -Y., Xiao, S., Xu, Y. -B., Yang, S., Yi, Q. -B., Zhang, D. -L., Zhang, F., Zhang, H. -M., Zhang, J. -P., Zhang, Z., Zhao, X. -Y., Zhao, Y., and Zheng, S. -J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The second brightest GRB in history, GRB230307A provides an ideal laboratory to study the details of GRB prompt emission thanks to its extraordinarily high photon statistics and its single broad pulse overall shape characterized by an energy-dependent fast-rise-exponential-decay (FRED) profile. Here we demonstrate that its broad pulse is composed of many rapidly variable short pulses, rather than being the superposition of many short pulses on top of a slow component. Such a feature is consistent with the picture of many mini-jets due to local magnetic reconnection events in a large emission zone far from the GRB central engine, as envisaged in the internal-collision-induced magnetic reconnection and turbulence (ICMART) model, but raises a great challenge to the internal shock models that attribute all variability components to collisions among different shells. Since relativistic mini-jets demand strong magnetization in the outflow, this work provides strong evidence for a Poynting-flux-dominated jet composition of this bright GRB., Comment: 7 pages and 2 figures in the main text. 27 pages and 9 figures in total
Published: 2023

3. The First GECAM Observation Results on Terrestrial Gamma-ray Flashes and Terrestrial Electron Beams

Author: Zhao, Y., Liu, J. C., Xiong, S. L., Xue, W. C., Yi, Q. B., Lu, G. P., Xu, W., Lyu, F. C., Sun, J. C., Peng, W. X., Zheng, C., Zhang, Y. Q., Cai, C., Xiao, S., Xie, S. L., Wang, C. W., Tan, W. J., An, Z. H., Chen, G., Du, Y. Q., Huang, Y., Gao, M., Gong, K., Guo, D. Y., He, J. J., Li, B., Li, G., Li, X. Q., Li, X. B., Liao, J. Y., Liang, J., Liang, X. H., Liu, Y. Q., Ma, X., Qiao, R., Song, L. M., Song, X. Y., Sun, X. L., Wang, J., Wang, J. Z., Wang, P., Wen, X. Y., Wu, H., Xu, Y. B., Yang, S., Zhang, B. X., Zhang, D. L., Zhang, F., Zhang, P., Zhang, H. M., Zhang, Z., Zhao, X. Y., Zheng, S. J., Zhang, K. K., Han, X. B., Wu, H. Y., Hu, T., Geng, H., Zhang, H. B., Lu, F. J., Zhang, S. N., and Yu, H.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: Gravitational-wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is a space-borne instrument dedicated to monitoring high-energy transients, including Terrestrial Gamma-ray Flashes (TGFs) and Terrestrial Electron Beams (TEBs). We implemented a TGF/TEB search algorithm for GECAM, with which 147 bright TGFs, 2 typical TEBs and 2 special TEB-like events are identified during an effective observation time of $\sim$9 months. We show that, with gamma-ray and charged particle detectors, GECAM can effectively identify and distinguish TGFs and TEBs, and measure their temporal and spectral properties in detail. A very high TGF-lightning association rate of $\sim$80\% is obtained between GECAM and GLD360 in east Asia region., Comment: The paper was accepted by Geophysical Research Letters on June 16th, 2023
Published: 2023
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4. The chromatic Point Spread Function of weak lensing measurement in Chinese Space Station survey Telescope

Author: Liu, Q. Y., Er, X. Z., Fan, Z. H., Liu, D. Z., Li, G. L., Wei, C. L., Ban, Z., Li, X. B., and Yue, D.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The weak gravitational lensing is a powerful tool in modern cosmology. To accurately measure the weak lensing signal, one has to control the systematic bias to a small level. One of the most difficult problems is how to correct the smearing effect of the Point Spread Function (PSF) on the shape of the galaxies. The chromaticity of PSF for a broad-band observation can lead to new subtle effects. Since the PSF is wavelength dependent and the spectrum energy distributions between stars and galaxies are different, the effective PSF measured from the star images will be different from that smears the galaxies. Such a bias is called colour bias. We estimate it in the optical bands of the Chinese Space Station Survey Telescope from simulated PSFs, and show the dependence on the colour and redshift of the galaxies. Moreover, due to the spatial variation of spectra over the galaxy image, there exists another higher-order bias, colour gradient bias. Our results show that both colour bias and colour gradient bias are generally below $0.1$ percent in CSST. Only for small-size galaxies, one needs to be careful about the colour gradient bias in the weak lensing analysis using CSST data.
Published: 2023
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5. GRANDMA and HXMT Observations of GRB 221009A -- the Standard-Luminosity Afterglow of a Hyper-Luminous Gamma-Ray Burst

Author: Kann, D. A., Agayeva, S., Aivazyan, V., Alishov, S., Andrade, C. M., Antier, S., Baransky, A., Bendjoya, P., Benkhaldoun, Z., Beradze, S., Berezin, D., Boër, M., Broens, E., Brunier, S., Bulla, M., Burkhonov, O., Burns, E., Chen, Y., Chen, Y. P., Conti, M., Coughlin, M. W., Cui, W. W., Daigne, F., Delaveau, B., Devillepoix, H. A. R., Dietrich, T., Dornic, D., Dubois, F., Ducoin, J. -G., Durand, E., Duverne, P. -A., Eggenstein, H. -B., Ehgamberdiev, S., Fouad, A., Freeberg, M., Froebrich, D., Ge, M. Y., Gervasoni, S., Godunova, V., Gokuldass, P., Gurbanov, E., Han, D. W., Hasanov, E., Hello, P., Hussenot-Desenonges, T., Inasaridze, R., Iskandar, A., Ismailov, N., Janati, A., Laz, T. Jegou du, Jia, S. M., Karpov, S., Kaeouach, A., Kiendrebeogo, R. W., Klotz, A., Kneip, R., Kochiashvili, N., Kunert, N., Lekic, A., Leonini, S., Li, C. K., Li, W., Li, X. B., Liao, J. Y., Logie, L., Lu, F. J., Mao, J., Marchais, D., Ménard, R., Morris, D., Natsvlishvili, R., Nedora, V., Noonan, K., Noysena, K., Orange, N. B., Pang, P. T. H., Peng, H. W., Pellouin, C., Peloton, J., Pradier, T., Pyshna, O., Rajabo, Y., Rau, S., Rinner, C., Rivet, J. -P., Romanov, F. D., Rosi, P., Rupchandani, V. A., Serrau, M., Shokry, A., Simon, A., Smith, K., Sokoliuk, O., Soliman, M., Song, L. M., Takey, A., Tillayev, Y., Ramirez, L. M. Tinjaca, Melo, I. Tosta e, Turpin, D., Postigo, A. de Ugarte, Vanaverbeke, S., Vasylenko, V., Vernet, D., Vidadi, Z., Wang, C., Wang, J., Wang, L. T., Wang, X. F., Xiong, Shaolin L., Xu, Y. P., Xue, W. C., Zeng, X., Zhang, S. N., Zhao, H. S., and Zhao, X. F.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: GRB 221009A is the brightest Gamma-Ray Burst (GRB) detected in more than 50 years of study. In this paper, we present observations in the X-ray and optical domains after the GRB obtained by the GRANDMA Collaboration (which includes observations from more than 30 professional and amateur telescopes) and the Insight-HXMT Collaboration. We study the optical afterglow with empirical fitting from GRANDMA+HXMT data, augmented with data from the literature up to 60 days. We then model numerically, using a Bayesian approach, the GRANDMA and HXMT-LE afterglow observations, that we augment with Swift-XRT and additional optical/NIR observations reported in the literature. We find that the GRB afterglow, extinguished by a large dust column, is most likely behind a combination of a large Milky-Way dust column combined with moderate low-metallicity dust in the host galaxy. Using the GRANDMA+HXMT-LE+XRT dataset, we find that the simplest model, where the observed afterglow is produced by synchrotron radiation at the forward external shock during the deceleration of a top-hat relativistic jet by a uniform medium, fits the multi-wavelength observations only moderately well, with a tension between the observed temporal and spectral evolution. This tension is confirmed when using the extended dataset. We find that the consideration of a jet structure (Gaussian or power-law), the inclusion of synchrotron self-Compton emission, or the presence of an underlying supernova do not improve the predictions, showing that the modelling of GRB22109A will require going beyond the most standard GRB afterglow model. Placed in the global context of GRB optical afterglows, we find the afterglow of GRB 221009A is luminous but not extraordinarily so, highlighting that some aspects of this GRB do not deviate from the global known sample despite its extreme energetics and the peculiar afterglow evolution., Comment: Accepted to ApJL for the special issue, 37 pages, 23 pages main text, 6 tables, 13 figures
Published: 2023
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6. Reanalysis of the X-ray burst associated FRB 200428 with Insight-HXMT observations

Author: Ge, M. Y., Liu, C. Z., Zhang, S. N., Lu, F. J., Zhang, Z., Chang, Z., Tuo, Y. L., Li, X. B., Li, C. K., Xiong, S. L., Cai, C., Li, X. F., Zhang, R., Dai, Z. G., Qu, J. L., Song, L. M., Zhang, S., and Wang, L. J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: A double-peak X-ray burst from the Galactic magnetar SGR J1935+2154 was discovered as associated with the two radio pulses of FRB 200428 separated by 28.97+-0.02 ms. Precise measurements of the timing and spectral properties of the X-ray bursts are helpful for understanding the physical origin of fast radio bursts (FRBs). In this paper, we have reconstructed some information about the hard X-ray events, which were lost because the High Energy X-ray Telescope (HE) onboard the Insight-HXMT mission was saturated by this extremely bright burst, and used the information to improve the temporal and spectral analyses of the X-ray burst. The arrival times of the two X-ray peaks by fitting the new Insight-HXMT/HE lightcurve with multi-Gaussian profiles are 2.77+-0.45 ms and 34.30+-0.56 ms after the first peak of FRB 200428, respectively, while these two parameters are 2.57+-0.52 ms and 32.5+-1.4 ms if the fitting profile is a fast rise and exponential decay function. The spectrum of the two X-ray peaks could be described by a cutoff power-law with cutoff energy ~60 keV and photon index ~1.4, the latter is softer than that of the underlying bright and broader X-ray burst when the two X-ray peaks appeared., Comment: 11 pages, 7 figures
Published: 2023
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7. GRB minimum variability timescale with Insight-HXMT and Swift: implications for progenitor models, dissipation physics and GRB classifications

Author: Camisasca, A. E., Guidorzi, C., Amati, L., Frontera, F., Song, X. Y., Xiao, S., Xiong, S. L., Zhang, S. N., Margutti, R., Kobayashi, S., Mundell, C. G., Ge, M. Y., Gomboc, A., Jia, S. M., Jordana-Mitjans, N., Li, C. K., Li, X. B., Maccary, R., Shrestha, M., Xue, W. C., and Zhang, S.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The dissipation process of GRB prompt emission is still unknown. Study of temporal variability may provide a unique way to discriminate the imprint of the inner engine activity from geometry and propagation related effects. We define the minimum variability timescale (MVT) as the shortest duration of individual pulses that shape a light curve for a sample of GRBs and test correlations with peak luminosity, Lorentz factor, and jet opening angle. We compare these correlations with predictions from recent numerical simulations for a relativistic structured -- possibly wobbling -- jet and assess the value of MTV as probe of prompt-emission physics. We used the peak detection algorithm mepsa to identify the shortest pulse within a GRB time history and estimate its full width half maximum (FWHM). We applied this framework to two sets of GRBs: Swift (from 2005 to July 2022) and Insight-HXMT (from June 2017 to July 2021, including 221009A). We then selected 401 GRBs with measured z to test for correlations. On average short GRBs have significantly shorter MVT than long GRBs. The MVT distribution of short GRBs with extended emission such as 060614 and 211211A is compatible only with that of short GRBs. This provides a new clue on the progenitor's nature. The MVT for long GRBs anticorrelates with peak luminosity. We confirm the anticorrelation with the Lorentz factor and find a correlation with the jet opening angle as estimated from the afterglow, along with an inverse correlation with the number of pulses. The MVT can identify the emerging putative new class of long GRBs that are suggested to be produced by compact binary mergers. For otherwise typical long GRBs, the different correlations between MVT and peak luminosity, Lorentz factor, jet opening angle, and number of pulses can be explained within the context of structured, possibly wobbling, weakly magnetised relativistic jets. (summarised), Comment: 18 pages, 15 figures, accepted by A&A
Published: 2023
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8. The peculiar spectral evolution of the new X-ray transient MAXI J0637-430

Author: Ma, R. C., Soria, R., Tao, L., Zhang, W., Qu, J. L., Zhang, S. N., Zhang, L., Qiao, E. L., Zhao, S. J., Ge, M. Y., Li, X. B., Huang, Y., Song, L. M., Zhang, S., Bu, Q. C., Wang, Y. N., Ma, X., and Jia, S. M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We studied the transient Galactic black hole candidate MAXI J0637-430 with data from Insight-HXMT, Swift and XMM-Newton. The broad-band X-ray observations from Insight-HXMT help us constrain the power-law component. MAXI J0637-430 is located at unusually high Galactic latitude; if it belongs to the Galactic thick disk, we suggest a most likely distance <7 kpc. Compared with other black hole transients, MAXI J0637-430 is also unusual for other reasons: a fast transition to the thermal dominant state at the start of the outburst; a low peak temperature and luminosity (we estimate them at ~ 0.7 keV and <0.1 times Eddington, respectively); a short decline timescale; a low soft-to-hard transition luminosity (<0.01 times Eddington). We argue that such properties are consistent with a small binary separation, short binary period (P ~ 2 hr), and low-mass donor star (M2 ~ 0.2 M_sun). Moreover, spectral modelling shows that a single disk-blackbody component is not a good fit to the thermal emission. Soft spectral residuals, and deviations from the standard L_disk ~ T^4 in relation, suggest the need for a second thermal component. We propose and discuss various scenarios for such component, in addition to those presented in previous studies of this source. For example, a gap in the accretion disk between a hotter inner ring near the innermost stable orbit, and a cooler outer disk. Another possibility is that the second thermal component is the thermal plasma emission from an ionized outflow.
Published: 2022
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9. The Second Catalog of Interplanetary Network Localizations of Konus Short Duration Gamma-Ray Bursts

Author: Svinkin, D., Hurley, K., Ridnaia, A., Lysenko, A., Frederiks, D., Golenetskii, S., Tsvetkova, A., Ulanov, M., Kokomov, A., Cline, T. L., Mitrofanov, I., Golovin, D., Kozyrev, A., Litvak, M., Sanin, A., Goldstein, A., Briggs, M. S., Wilson-Hodge, C., Burns, E., von Kienlin, A., Zhang, X. -L., Rau, A., Savchenko, V., Bozzo, E., Ferrigno, C., Barthelmy, S., Cummings, J., Krimm, H., Palmer, D. M., Tohuvavohu, A., Yamaoka, K., Ohno, M., Fukazawa, Y., Hanabata, Y., Takahashi, T., Tashiro, M., Terada, Y., Murakami, T., Makishima, K., Boynton, W., Fellows, C. W., Harshman, K. P., Enos, H., Starr, R., Goldsten, J., Gold, R., Ursi, A., Tavani, M., Bulgarelli, A., Casentini, C., Del Monte, E., Evangelista, Y., Galli, M., Longo, F., Marisaldi, M., Parmiggiani, N., Pittori, C., Romani, M., Verrecchia, F., Smith, D. M., Hajdas, W., Xiao, S., Cai, C., Yi, Q. B., Zhang, Y. Q., Xiong, S. L., Li, X. B., Huang, Y., Li, C. K., Zhang, S. N., Song, L. M., Liu, C. Z., Li, X. Q., Peng, W. X., and Martinez-Castellanos, I.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present the catalog of Interplanetary Network (IPN) localizations for 199 short-duration gamma-ray bursts (sGRBs) detected by the Konus-Wind (KW) experiment between 2011 January 1 and 2021 August 31, which extends the initial sample of IPN localized KW sGRBs (arXiv:1301.3740) to 495 events. We present the most comprehensive IPN localization data on these events, including probability sky maps in HEALPix format., Comment: Published in ApJS
Published: 2022
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10. Insight-HXMT Detections of Hard X-ray Tails in Scorpius X-1

Author: Ding, G. Q., Qu, J. L., Song, L. M., Huang, Y., Zhang, S., Bu, Q. C., Ge, M. Y., Li, X. B., Tao, L., Ma, X., Chen, Y. P., and Tuo, Y. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Using the observations of the high-energy (HE) detector of the Hard X-ray Modulation Telescope (Insight-HXMT) for Scorpius X-1 in 2018, we search for hard X-ray tails in the hard X-ray spectra in ~30-200 keV. The hard X-ray tails are found throughout the Z-track on the hardness-intensity diagram and they harden and fade away from the horizontal branch (HB), through the normal branch (NB), to the flaring branch (FB). Comparing the hard X-ray spectra between Cyg X-1 and Sco X-1, it is concluded that the hard X-ray spectrum of Cyg X-1 shows high-energy cutoff, implying a hot corona in it, but the high-energy cutoff does not reveal in the hard X-ray spectrum of Sco X-1. Jointly fitting the HE spectrum with the medium-energy and low-energy spectra of Sco X-1 in ~2-200 keV, it is suggested that the upscattering Comptonization of the neutron star (NS) emission photons by the energetic free-falling electrons onto the NS or by the hybrid electrons in the boundary layer between the NS and the accretion disk could be responsible for the hard X-ray tails of Sco X-1 on the HB and NB, but neither of the two mechanisms can be responsible for the hard X-ray tail on the FB. Some possible origins for the peculiar hard X-ray tail of FB are argued., Comment: 26 pages, 7 figures
Published: 2022
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11. Peculiar disk behaviors of the black hole candidate MAXI J1348-630 in the hard state observed by Insight-HXMT and Swift

Author: Zhang, W., Tao, L., Soria, R., Qu, J. L., Zhang, S. N., Weng, S. S., zhang, L., Wang, Y. N., Huang, Y., Ma, R. C., Zhang, S., Ge, M. Y., Song, L. M., Ma, X., Bu, Q. C., Cai, C., Cao, X. L., Chang, Z., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y., Chen, Y. P., Cui, W. W., Du, Y. Y., Gao, G. H., Gao, H., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, C. Z., Liu, H. X., Liu, H. W., Liu, X. J., Lu, F. J., Lu, X. F., Luo, Q., Luo, T., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Ren, X. Q., Sai, N., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, L. J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, R. J., Yang, S., Yang, Y. J., Yang, Y. R., Yi, Q. B., Yin, Q. Q., Yuan, Y., Zhang, F., Zhang, H. M., Zhang, P., Zhang, W. C., Zhang, Y. F., Zhang, Y. H., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present a spectral study of the black hole candidate MAXI J1348-630 during its 2019 outburst, based on monitoring observations with Insight-HXMT and Swift. Throughout the outburst, the spectra are well fitted with power-law plus disk-blackbody components. In the soft-intermediate and soft states, we observed the canonical relation L ~ T_in^4 between disk luminosity L and peak colour temperature T_in, with a constant inner radius R_in (traditionally identified with the innermost stable circular orbit). At other stages of the outburst cycle, the behaviour is more unusual, inconsistent with the canonical outburst evolution of black hole transients. In particular, during the hard rise, the apparent inner radius is smaller than in the soft state (and increasing), and the peak colour temperature is higher (and decreasing). This anomalous behaviour is found even when we model the spectra with self-consistent Comptonization models, which take into account the up-scattering of photons from the disk component into the power-law component. To explain both those anomalous trends at the same time, we suggest that the hardening factor for the inner disk emission was larger than the canonical value of ~1.7 at the beginning of the outburst. A more physical trend of radii and temperature evolution requires a hardening factor evolving from ~3.5 at the beginning of the hard state to ~1.7 in the hard intermediate state. This could be evidence that the inner disk was in the process of condensing from the hot, optically thin medium and had not yet reached a sufficiently high optical depth for its emission spectrum to be described by the standard optically-thick disk solution., Comment: 20 pages, 10 figures, 4 tables, accepted by ApJ
Published: 2022
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12. Effects of Damage Mode on Crack Propagation Pattern in Additively Manufactured Honeycomb Cellular Panel

Author: Zhang, X. R., Deng, Q. T., and Li, X. B.
Published: 2023
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13. GECAM detection of a bright type-I X-ray burst from 4U 0614+09: confirmation its spin frequency at 413 Hz

Author: Chen, Y. P., Li, J., Xiong, S. L., Ji, L., Zhang, S., Peng, W. X., Qiao, R., Li, X. Q., Wen, X. Y., Song, L. M., Zheng, S. J., Song, X. Y., Zhao, X. Y., Huang, Y., Lu, F. J., Zhang, S. N., Xiao, S., Cai, C., Zhang, B. X., An, Z. H., Chen, C., Chen, G., Chen, W., Dai, G. Q., Du, Y. Q., Gao, M., Gong, K., Guo, D. Y., Guo, Z. W., He, J. J., Li, B., Li, C., Li, C. Y., Li, G., Li, J. H., Li, L., Li, Q. X., Li, X. B., Li, Y. G., Liang, J., Liang, X. H., Liao, J. Y., Liu, J. C., Liu, X. J., Liu, Y. Q., Luo, Q., Ma, X., Meng, B., Ou, G., Shi, D. L., Shi, F., Shi, J. Y., Sun, G. X., Sun, X. L., Tuo, Y. L., Wang, C. W., Wang, H., Wang, H. Y., Wang, J., Wang, J. Z., Wang, P., Wang, Y. S., Wang, Y. X., Wen, X., Wu, H., Xie, S. L., Xu, Y. B., Xu, Y. P., Xue, W. C., Yang, S., Yao, M., Ye, J. Y., Yi, Q. B., Zhang, C. M., Zhang, C. Y., Zhang, D. L., Zhang, Fan, Zhang, Fei, Zhang, H. M., Zhang, K., Zhang, P., Zhang, X. L., Zhang, Y. Q., Zhang, Z., Zhao, G. Y., Zhao, S. Y., Zhao, Y., Zheng, C., Zhou, X., and Zhu, Y.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: One month after launching Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM), a bright thermonuclear X-ray burst from 4U~0614+09, was observed on January 24, 2021. We report the time-resolved spectroscopy of the burst and a burst oscillation detection at 413 Hz with a fractional amplitude 3.4\% (rms). This coincides with the burst oscillation previously discovered with \textit{Swift}/BAT \citep{Strohmayer2008}, and therefore confirms the spin frequency of this source. This burst is the brightest one in the normal bursts (except the superburst) ever detected from 4U~0614+09, which leads to an upper limit of distance estimation as 3.1 kpc. The folded light curve during the burst oscillation shows a multi-peak structure, which is the first case observed during a single burst oscillation in nonpulsating sources. The multi-peak profile could be due to additional harmonics of the burst oscillation, which is corresponding to several brighter/fainter spots at the stellar surface.
Published: 2021
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14. Ground-based calibration and characterization of GRD of GECAM: 8-160 keV

Author: He, J. J., An, Z. H., Peng, W. X., Li, X. Q., Xiong, S. L., Zhang, D. L., Qiao, R., Guo, D. Y., Cai, C., Chang, Z., Chen, C., Chen, G., Du, Y. Y., Gao, M., Gao, R., Gong, K., Hou, D. J., Li, C. Y., Li, G., Li, L., Li, M. S., Li, X. B., Li, X. F., Li, Y. G., Liang, X. H., Liu, J. C., Liu, X. J., Liu, Y. Q., Lu, H., Ma, X., Meng, B., Shi, F., Song, L. M., Sun, X. L., Wang, C. W., Wang, H., Wang, H. Z., Wang, J. Z., Wang, Y. S., Wen, X., Wen, X. Y., Xiao, S., Xu, Y. B., Xu, Y. P., Xue, W. C., Yang, J. W., Yang, S., Yi, Q. B., Zhang, C. M., Zhang, C. Y., Zhang, Fan, Zhang, Fei, Zhang, P., Zhang, S. N., Zhang, Y. Q., Zhao, X. Y., Zhao, Y., Zheng, C., Zheng, S. J., Zhou, X., and Zhu, Y.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: As the main detector of the GECAM satellite, the calibration of the energy response and detection efficiency of the GRD detector is the main content of the ground-based calibration. The calibration goal requires the calibrated energy points to sample the full energy range (8 keV-2 MeV) as much as possible. The low energy band (8-160 keV) is calibrated with the X-ray beam, while the high energy band (>160 keV) with radioactive sources. This article mainly focuses on the calibration of the energy response and detection efficiency in the 8-160 keV with a refined measurement around the absorption edges of the lanthanum bromide crystal. The GRD performances for different crystal types, data acquisition modes, working modes, and incident positions are also analyzed in detail. We show that the calibration campaign is comprehensive, and the calibration results are generally consistent with simulations as expected., Comment: 16 pages,46 figures
Published: 2021

15. Search for Gamma-Ray Bursts and Gravitational Wave Electromagnetic Counterparts with High Energy X-ray Telescope of \textit{Insight}-HXMT

Author: Cai, C., Xiong, S. L., Li, C. K., Liu, C. Z., Zhang, S. N., Li, X. B., Song, L. M., Li, B., Xiao, S., Yi, Q. B., Zhu, Y., Zheng, Y. G., Chen, W., Luo, Q., Huang, Y., Song, X. Y., Zhao, H. S., Zhao, Y., Zhang, Z., Bu, Q. C., Cao, X. L., Chang, Z., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y., Chen, Y. P., Cui, W. W., Du, Y. Y., Gao, G. H., Gao, H., Ge, M. Y., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Kong, L. D., Li, G., Li, T. P., Li, W., Li, X., Li, X. F., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, H. W., Liu, H. X., Liu, X. J., Lu, F. J., Lu, X. F., Luo, T., Ma, R. C., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Qu, J. L., Ren, X. Q., Sai, N., Sun, L., Tan, Y., Tao, L., Tuo, Y. L., Wang, C., Wang, L. J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xu, Y. P., Yang, R. J., Yang, S., Yang, Y. J., Yang, Y. R., Yang, X. J., Yin, Q. Q., You, Y., Zhang, F., Zhang, H. M., Zhang, J., Zhang, P., Zhang, S., Zhang, W. C., Zhang, W., Zhang, Y. F., Zhang, Y. H., Zhao, X. F., Zheng, S. J., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The High Energy X-ray telescope (HE) on-board the Hard X-ray Modulation Telescope (\textit{Insight}-HXMT) can serve as a wide Field of View (FOV) gamma-ray monitor with high time resolution ($\mu$s) and large effective area (up to thousands cm$^2$). We developed a pipeline to search for Gamma-Ray Bursts (GRBs), using the traditional signal-to-noise ratio (SNR) method for blind search and the coherent search method for targeted search. By taking into account the location and spectrum of the burst and the detector response, the targeted coherent search is more powerful to unveil weak and sub-threshold bursts, especially those in temporal coincidence with Gravitational Wave (GW) events. Based on the original method in literature, we further improved the coherent search to filter out false triggers caused by spikes in light curves, which are commonly seen in gamma-ray instruments (e.g. \textit{Fermi}/GBM, \textit{POLAR}). We show that our improved targeted coherent search method could eliminate almost all false triggers caused by spikes. Based on the first two years of \textit{Insight}-HXMT/HE data, our targeted search recovered 40 GRBs, which were detected by either \textit{Swift}/BAT or \textit{Fermi}/GBM but too weak to be found in our blind search. With this coherent search pipeline, the GRB detection sensitivity of \textit{Insight}-HXMT/HE is increased to about 1.5E-08 erg/cm$^2$ (200 keV$-$3 MeV). We also used this targeted coherent method to search \textit{Insight}-HXMT/HE data for electromagnetic (EM) counterparts of LIGO-Virgo GW events (including O2 and O3a runs). However, we did not find any significant burst associated with GW events., Comment: 12 pages, 14 figures, 5 tables; accepted for publication in MNRAS
Published: 2021
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16. Accretion Torque Reversals in GRO J1008-57 Revealed by Insight-HXMT

Author: Wang, W., Tang, Y. M., Tuo, Y. L., Epili, P. R., Zhang, S. N., Song, L. M., Lu, F. J., Qu, J. L., Zhang, S., Ge, M. Y., Huang, Y., Li, B., Bu, Q. C., Cai, C., Cao, X. L., Chang, Z., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y., Chen, Y. P., Cui, W. W., Du, Y. Y., Gao, G. H., Gao, H., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Kong, L. D., Li, C. K., Li, G., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, C. Z., Liu, H. X., Liu, H. W., Lu, X. F., Luo, Q., Luo, T., Ma, R. C., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Ren, X. Q., Sai, N., Song, X. Y., Sun, L., Tao, L., Wang, C., Wang, L. J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Xu, Y. P., Yang, R. J., Yang, S., Yang, J. J., Yang, Y. J., Yi, B. B., Yin, Q. Q., You, Y., Zhang, F., Zhang, H. M., Zhang, J., Zhang, P., Zhang, W., Zhang, W. C., Zhang, Y. F., Zhang, Y. H., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: GRO J1008-57, as a Be/X-ray transient pulsar, is considered to have the highest magnetic field in known neutron star X-ray binary systems. Observational data of the X-ray outbursts in GRO J1008-57 from 2017 to 2020 were collected by the Insight-HXMT satellite. In this work, the spin period of the neutron star in GRO J1008-57 was determined to be about 93.28 seconds in August 2017, 93.22 seconds in February 2018, 93.25 seconds in June 2019 and 93.14 seconds in June 2020. GRO J1008-57 evolved in the spin-up process with a mean rate of $-(2.10\pm 0.05)\times$10$^{-4}$ s/d from 2009 -- 2018, and turned into a spin down process with a rate of $(6.7\pm 0.6)\times$10$^{-5}$ s/d from Feb 2018 to June 2019. During the type II outburst of 2020, GRO J1008-57 had the spin-up torque again. During the torque reversals, the pulse profiles and continuum X-ray spectra did not change significantly, and the cyclotron resonant scattering feature around 80 keV was only detected during the outbursts in 2017 and 2020. Based on the observed mean spin-up rate, we estimated the inner accretion disk radius in GRO J1008-57 (about 1 - 2 times of the Alfv\'{e}n radius) by comparing different accretion torque models of magnetic neutron stars. During the spin-down process, the magnetic torque should dominate over the matter accreting inflow torque, and we constrained the surface dipole magnetic field $B\geq 6\times 10^{12}$ G for the neutron star in GRO J1008-57, which is consistent with the magnetic field strength obtained by cyclotron line centroid energy., Comment: 10 pages, 5 figures, and 3 tables, the Journal of High Energy Astrophysics in press
Published: 2021

17. QPOs and Orbital elements of X-ray binary 4U 0115+63 during the 2017 outburst observed by Insight-HXMT

Author: Ding, Y. Z., Wang, W., Zhang, P., Bu, Q. C., Cai, C., Cao, X. L., Zhi, C., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y., Chen, Y. P., Cui, W. W., Du, Y. Y., Gao, G. H., Gao, H., Ge, M. Y., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, C. Z., Liu, H. X., Liu, H. W., Liu, X. J., Lu, F. J., Lu, X. F., L., Q., T., L., Ma, R. C., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Qu, J. L., Ren, X. Q., Sai, N., Song, L. M., Song, X. Y., Sun, L., Tan, Y., Tao, L., Tuo, Y. L., Wang, L. J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Xu, Y. P., Yang, R. J., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, F., Zhang, H. M., Zhang, J., Zhang, S., Zhang, S. N., Zhang, W. C., Zhang, W., Zhang, Y. F., Zhang, Y. H., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: In this paper, we presented a detailed timing analysis of a prominent outburst of 4U 0115+63 detected by \textit{Insight}-HXMT in 2017 August. The spin period of the neutron star was determined to be $3.61398\pm 0.00002$ s at MJD 57978. We measured the period variability and extract the orbital elements of the binary system. The angle of periastron evolved with a rate of $0.048\pm0.003$ $yr^{-1}$. The light curves are folded to sketch the pulse profiles in different energy ranges. A multi-peak structure in 1-10 keV is clearly illustrated. We introduced wavelet analysis into our data analysis procedures to study QPO signals and perform a detailed wavelet analysis in many different energy ranges. Through the wavelet spectra, we report the discovery of a QPO at the frequency $\sim 10$ mHz. In addition, the X-ray light curves showed multiple QPOs in the period of $\sim 16-32 $ s and $\sim 67- 200 $ s. We found that the $\sim100$ s QPO was significant in most of the observations and energies. There exist positive relations between X-ray luminosity and their Q-factors and S-factors, while the QPO periods have no correlation with X-ray luminosity. In wavelet phase maps, we found that the pulse phase of $\sim 67- 200 $ s QPO drifting frequently while the $\sim 16-32 $ s QPO scarcely drifting. The dissipation of oscillations from high energy to low energy was also observed. These features of QPOs in 4U 0115+63 provide new challenge to our understanding of their physical origins., Comment: 14 pages, 9 figures, and 6 tables. This work has been submitted to MNRAS after the referee's report
Published: 2021
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18. Insight-HXMT observations of Swift J0243.6+6124: the evolution of RMS pulse fractions at super-Eddington luminosity

Author: Wang, P. J., Kong, L. D., Zhang, S., Chen, Y. P., Zhang, S. N., Qu, J. L., Ji, L., Tao, L., Ge, M. Y., Lu, F. J., Chen, L., Song, L. M., Li, T. P., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Bu, Q. C., Cai, C., Chang, Z., Chen, G., Chen, T. X., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Shang, R. C., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, L. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, J. W., Yang, S., Yang, Yan Ji, Yang, Yi Jung, Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W. C., Zhang, W., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Zhao, Zhang, Zhi, Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., Zhou, D. K., Zhou, J. F., Zhu, Y. X., Zhu, Y., and Zhuang, R. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Based on Insight-HXMT data, we report on the pulse fraction evolution during the 2017-2018 outburst of the newly discovered first Galactic ultraluminous X-ray source (ULX) Swift J0243.6+6124. The pulse fractions of 19 observation pairs selected in the rising and fading phases with similar luminosity are investigated. The results show a general trend of the pulse fraction increasing with luminosity and energy at super-critical luminosity. However, the relative strength of the pulsation between each pair evolves strongly with luminosity. The pulse fraction in the rising phase is larger at luminosity below $7.71\times10^{38}$~erg~s$^{-1}$, but smaller at above. A transition luminosity is found to be energy independent. Such a phenomena is firstly confirmed by Insight-HXMT observations and we speculate it may have relation with the radiation pressure dominated accretion disk.
Published: 2020
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19. Physical origin of the nonphysical spin evolution of MAXI J1820+070

Author: Guan, J., Tao, L., Qu, J. L., Zhang, S. N., Zhang, W., Zhang, S., Ma, R. C., Ge, M. Y., Song, L. M., Lu, F. J., Li, T. P., Xu, Y. P., Chen, Y., Cao, X. L., Liu, C. Z., Zhang, L., Wang, Y. N., Chen, Y. P., Bu, Q. C., Cai, C., Chang, Z., Chen, L., Chen, T. X., Chen, Y. B., Cui, W. W., Du, Y. Y., Gao, G. H., Gao, H., Gu, Y. D., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, W., Li, X., Li, X. B., Li, X. F., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, H. W., Liu, H. X., Liu, X. J., Lu, X. F., Luo, Q., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Ren, X. Q., Sai, N., Song, X. Y., Sun, L., Tan, Y., Wang, C., Wang, L. J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, R. J., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, F., Zhang, H. M., Zhang, J., Zhang, P., Zhang, W. C., Zhang, Y. F., Zhang, Y. H., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, 83C57
Abstract: We report on the Insight-HXMT observations of the new black hole X-ray binary MAXI J1820+070 during its 2018 outburst. Detailed spectral analysis via the continuum fitting method shows an evolution of the inferred spin during its high soft sate. Moreover, the hardness ratio, the non-thermal luminosity and the reflection fraction also undergo an evolution, exactly coincident to the period when the inferred spin transition takes place. The unphysical evolution of the spin is attributed to the evolution of the inner disc, which is caused by the collapse of a hot corona due to condensation mechanism or may be related to the deceleration of a jet-like corona. The studies of the inner disc radius and the relation between the disc luminosity and the inner disc radius suggest that, only at a particular epoch, did the inner edge of the disc reach the innermost stable circular orbit and the spin measurement is reliable. We then constrain the spin of MAXI J1820+070 to be a*=0.2^{+0.2}_{-0.3}. Such a slowly spinning black hole possessing a strong jet suggests that its jet activity is driven mainly by the accretion disc rather than by the black hole spin., Comment: 14 pages, 13 figures, 5 tables, accepted for publication in MNRAS
Published: 2020
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20. X-ray reprocessing in accreting pulsar GX 301-2 observed with Insight-HXMT

Author: Ji, L., Doroshenko, V., Suleimanov, V., Santangelo, A., Orlandini, M., Liu, J., Ducci, L., Zhang, S. N., Nabizadeh, A., Gavran, D., Zhang, S., Ge, M. Y., Li, X. B., Tao, L., Bu, Q. C., Qu, J. L., Lu, F. J., Chen, L., Song, L. M., Li, T. P., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Cai, C., Chang, Z., Chen, T. X., Chen, Y. P., Cui, W. W., Du, Y. Y., Gao, G. H., Gao, H., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, W., Li, X., Li, X. F., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, H. X., Liu, H. W., Liu, X. J., Lu, X. F., Luo, Q., Luo, T., Ma, R. C., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Ren, X. Q., Sai, N., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, L. J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, R. J., Yang, S., Yang, Yan-Ji, Yang, Yi-Jung, Yi, Q. B., Yin, Q. Q., You, Y., Zhang, F., Zhang, H. M., Zhang, J., Zhang, P., Zhang, W., Zhang, W. C., Zhang, Yi, Zhang, Y. F., Zhang, Y. H., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We investigate the absorption and emission features in observations of GX 301-2 detected with Insight-HXMT/LE in 2017-2019. At different orbital phases, we found prominent Fe Kalpha, Kbeta and Ni Kalpha lines, as well as Compton shoulders and Fe K-shell absorption edges. These features are due to the X-ray reprocessing caused by the interaction between the radiation from the source and surrounding accretion material. According to the ratio of iron lines Kalpha and Kbeta, we infer the accretion material is in a low ionisation state. We find an orbital-dependent local absorption column density, which has a large value and strong variability around the periastron. We explain its variability as a result of inhomogeneities of the accretion environment and/or instabilities of accretion processes. In addition, the variable local column density is correlated with the equivalent width of the iron Kalpha lines throughout the orbit, which suggests that the accretion material near the neutron star is spherically distributed., Comment: 10 pages, 5 figures, 2 tables, accepted for publication in MNRAS
Published: 2020
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21. Insight-HXMT observations of a possible fast transition from jet to wind dominated state during a huge flare of GRS~1915+105

Author: Kong, L. D., Zhang, S., Chen, Y. P., Zhang, S. N., Ji, L., Wang, P. J., Tao, L., Ge, M. Y., Liu, C. Z., Song, L. M., Lu, F. J., Qu, J. L., Li, T. P., Xu, Y. P., Cao, X. L., Chen, Y., Bu, Q. C., Cai, C., Chang, Z., Chen, G., Chen, L., Chen, T. X., Cui, W. W., Du, Y. Y., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Li, B., Li, C. K., Li, G., Li, W., Li, X., Li, X. B., Li, X. F., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, H. W., Liu, H. X., Liu, X. J., Lu, X. F., Luo, Q., Luo, T., Ma, R. C., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Ren, X. Q., Sai, N., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, L. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, R. J., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, F., Zhang, H. M., Zhang, J., Zhang, P., Zhang, W. C., Zhang, W., Zhang, Y. F., Zhang, Y. H., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present the analysis of the brightest flare that was recorded in the \emph{Insight}-HMXT data set, in a broad energy range (2$-$200 keV) from the microquasar GRS~1915+105 during an unusual low-luminosity state. This flare was detected by \emph{Insight}-HXMT among a series of flares during 2 June 2019 UTC 16:37:06 to 20:11:36, with a 2-200 keV luminosity of 3.4$-$7.27$\times10^{38}$ erg s$^{-1}$. Basing on the broad-band spectral analysis, we find that the flare spectrum shows different behaviors during bright and faint epochs. The spectrum of the flare can be fitted with a model dominated by a power-law component. Additional components show up in the bright epoch with a hard tail and in the faint epoch with an absorption line $\sim$ 6.78 keV. The reflection component of the latter is consistent with an inner disk radius $\sim$ 5 times larger than that of the former. These results on the giant flare during the "unusual" low-luminosity state of GRS~1915+105 may suggest that the source experiences a possible fast transition from a jet-dominated state to a wind-dominated state. We speculate that the evolving accretion disk and the large-scale magnetic field may play important roles in this peculiar huge flare.
Published: 2020
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22. A variable ionized disk wind in the black-hole candidate EXO 1846-031

Author: Wang, Yanan, Ji, Long, Garcia, Javier A., Dauser, Thomas, Mendez, Mariano, Mao, Junjie, Tao, L., Altamirano, Diego, Maggi, Pierre, Zhang, S. N., Ge, M. Y., Zhang, L., Qu, J. L., Zhang, S., Ma, X., Lu, F. J., Li, T. P., Huang, Y., Zheng, S. J., Chang, Z., Tuo, Y. L., Song, L. M., Xu, Y. P., Chen, Y., Liu, C. Z., Bu, Q. C., Cai, C., Cao, X. L., Chen, L., Chen, T. X., Chen, Y. P., Cui, W. W., Du, Y. Y., Gao, G. H., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, W., Li, X., Li, X. B., Li, X. F., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, H. W., Liu, X. J., Lu, X. F., Luo, Q., Luo, T., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Shang, R. C., Song, X. Y., Sun, L., Tan, Y., Wang, W. S., Wang, Y. D., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, F., Zhang, H. M., Zhang, J., Zhang, W. C., Zhang, W., Zhang, Y. F., Zhao, H. S., Zhao, X. F., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: After 34 years, the black-hole candidate EXO 1846-031 went into outburst again in 2019. We investigate its spectral properties in the hard intermediate and the soft states with NuSTAR and Insight-HXMT. A reflection component has been detected in the two spectral states but possibly originating from different illumination spectra: in the intermediate state, the illuminating source is attributed to a hard coronal component, which has been commonly observed in other X-ray binaries, whereas in the soft state the reflection is probably produced by the disk self-irradiation. Both cases support EXO 1846-031 as a low inclination system of ~40 degrees. An absorption line is clearly detected at ~7.2 keV in the hard intermediate state, corresponding to a highly ionized disk wind (log {\xi} > 6.1) with a velocity up to 0.06c. Meanwhile, quasi-simultaneous radio emissions have been detected before and after the X-rays, implying the co-existence of disk winds and jets in this system. Additionally, the observed wind in this source is potentially driven by magnetic forces. The absorption line disappeared in the soft state and a narrow emission line appeared at ~6.7 keV on top of the reflection component, which may be evidence for disk winds, but data with the higher spectral resolution are required to examine this., Comment: Accepted for publication in ApJ
Published: 2020
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23. Constraining the transient high-energy activity of FRB180916.J0158+65 with Insight-HXMT followup observations

Author: Guidorzi, C., Orlandini, M., Frontera, F., Nicastro, L., Xiong, S. L., Liao, J. Y., Li, G., Zhang, S. N., Amati, L., Virgilli, E., Zhang, S., Bu, Q. C., Cai, C., Cao, X. L., Chang, Z., Chen, L., Chen, T. X., Chen, Y., Chen, Y. P., Cui, W. W., Du, Y. Y., Gao, G. H., Gao, H., Gao, M., Ge, M. Y., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Z. W., Liang, X. H., Liu, B. S., Liu, C. Z., Liu, H. X., Liu, H. W., Liu, X. J., Lu, F. J., Lu, X. F., Luo, Q., Luo, T., Ma, R. C., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Qu, J. L, Ren, X. Q., Sai, N., Song, L. M., Song, X. Y., Sun, L., Tan, Y., Tao, L., Tuo, Y. L., Wang, C., Wang, L. J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xu, Y. P., Yang, R., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, F., Zhang, H. M., Zhang, J., Zhang, P., Zhang, W. C., Zhang, W., Zhang, Y. F., Zhang, Y. H., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., and Zhou, D. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: A link between magnetars and fast radio burst (FRB) sources has finally been established. In this context, one of the open issues is whether/which sources of extra galactic FRBs exhibit X/gamma-ray outbursts and whether it is correlated with radio activity. We aim to constrain possible X/gamma-ray burst activity from one of the nearest extragalactic FRB sources currently known over a broad energy range, by looking for bursts over a range of timescales and energies that are compatible with being powerful flares from extragalactic magnetars. We followed up the as-yet nearest extragalactic FRB source at a mere 149 Mpc distance, the periodic repeater FRB180916.J0158+65, during the active phase on February 4-7, 2020, with the Insight-Hard X-ray Modulation Telescope (HXMT). Taking advantage of the combination of broad band, large effective area, and several independent detectors available, we searched for bursts over a set of timescales from 1 ms to 1.024 s with a sensitive algorithm, that had previously been characterised and optimised. Moreover, through simulations we studied the sensitivity of our technique in the released energy-duration phase space for a set of synthetic flares and assuming different energy spectra. We constrain the possible occurrence of flares in the 1-100 keV energy band to E<10^46 erg for durations <0.1 s over several tens of ks exposure. We can rule out the occurrence of giant flares similar to the ones that were observed in the few cases of Galactic magnetars. The absence of reported radio activity during our observations does not allow us to make any statements on the possible simultaneous high-energy emission., Comment: 10 pages, 3 figures, accepted by A&A
Published: 2020
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24. Insight-HXMT firm detection of the highest energy fundamental cyclotron resonance scattering feature in the spectrum of GRO J1008-57

Author: Ge, M. Y., Ji, L., Zhang, S. N., Santangelo, A., Liu, C. Z., Doroshenko, V., Staubert, R., Qu, J. L., Zhang, S., Lu, F. J., Song, L. M., Li, T. P., Tao, L., Xu, Y. P., Cao, X. L., Chen, Y., Bu, Q. C., Cai, C., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Shang, R. C., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, L. J., Wang, W. S., Wang, Y. D., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Xu, H., Yang, J. W., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W. C., Zhang, W., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., Zhou, D. K., Zhou, J. F., Zhuang, R. L., Zhu, Y. X., and Zhu, Y.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on the observation of the accreting pulsar GRO J1008-57 performed by Insight-HXMT at the peak of the source's 2017 outburst. Pulsations are detected with a spin period of 93.283(1) s. The pulse profile shows double peaks at soft X-rays, and only one peak above 20 keV. The spectrum is well described by the phenomenological models of X-ray pulsars. A cyclotron resonant scattering feature is detected with very high statistical significance at a centroid energy of $E_{\rm cyc}=90.32_{-0.28}^{+0.32}$ keV, for the reference continuum and line models, HIGHECUT and GABS respectively. Detection is very robust with respect to different continuum models. The line energy is significantly higher than what suggested from previous observations, which provided very marginal evidence for the line. This establishes a new record for the centroid energy of a fundamental cyclotron resonant scattering feature observed in accreting pulsars. We also discuss the accretion regime of the source during the Insight-HXMT observation., Comment: 8 pages, 3 figures, accepted for publication in ApJL
Published: 2020
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25. HXMT Identification of a non-thermal X-ray burst from SGR J1935+2154 and with FRB 200428

Author: Li, C. K., Lin, L., Xiong, S. L., Ge, M. Y., Li, X. B., Li, T. P., Lu, F. J., Zhang, S. N., Tuo, Y. L., Nang, Y., Zhang, B., Xiao, S., Chen, Y., Song, L. M., Xu, Y. P., Liu, C. Z., Jia, S. M., Cao, X. L., Qu, J. L., Zhang, S., Gu, Y. D., Liao, J. Y., Zhao, X. F., Tan, Y., Nie, J. Y., Zhao, H. S., Zheng, S. J., Zheng, Y. G., Luo, Q., Cai, C., Li, B., Xue, W. C., Bu, Q. C., Chang, Z., Chen, G., Chen, T. X., Chen, Y. B., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Kong, L. D., Li, G., Li, M. S., Li, W., Li, X., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liu, B. S., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, T., Ma, X., Meng, B., Ou, G., Sai, N., Shang, R. C., Song, X. Y., Sun, L., Tao, L., Wang, C., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xu, H., Yang, J. W., Yang, S., Yang, Y. J., Yang, Yi-Jung, Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Yue, Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Zhi, Zhang, Z. L., Zhou, D. K., Zhou, J. F., Zhu, Y., Zhu, Y. X., and Zhuang, R. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: Fast radio bursts (FRBs) are short pulses observed in radio band from cosmological distances. One class of models invoke soft gamma-ray repeaters (SGRs), or magnetars, as the sources of FRBs. Some radio pulses have been observed from some magnetars, however, no FRB-like events had been detected in association any magnetar burst, including one giant flare. Recently, a pair of FRB-like bursts (FRB 200428 hereafter) separated by milliseconds (ms) were detected from the general direction of the Galactic magnetar SGR J1935+2154. Here we report the detection of a non-thermal X-ray burst in the 1-250 keV energy band with the Insight-HXMT satellite, which we identify as emitted from SGR J1935+2154. The burst showed two hard peaks with a separation of 34 ms, broadly consistent with that of the two bursts in FRB 200428. The delay time between the double radio and X-ray peaks is about 8.57 s, fully consistent with the dispersion delay of FRB 200428. We thus identify the non-thermal X-ray burst is associated with FRB 200428 whose high energy counterpart is the two hard peaks in X-ray. Our results suggest that the non-thermal X-ray burst and FRB 200428 share the same physical origin in an explosive event from SGR J1935+2154., Comment: 24 pages, 9 figures, 6 tables; initial submission to a journal on May 9th, 2020. Significant changes include updated localization and detailed spectral evolution of the X-ray burst, and better determination of the two narrow X-ray peaks corresponding to the two radio pulses. Conclusions are strengthened. Nature Astronomy online on Feb. 18, 2021
Published: 2020
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26. Insight-HXMT insight into switch of the accretion mode: the case of the X-ray pulsar 4U 1901+03

Author: Tuo, Y. L., Ji, L., Tsygankov, S. S., Mihara, T., Song, L. M., Ge, M. Y., Nabizadeh, A., Tao, L., Qu, J. L., Zhang, Y., Zhang, S., Zhang, S. N., Bu, Q. C., Chen, L., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Cai, C., Chang, Z., Chen, G., Chen, T. X., Chen, Y. B., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, B. S., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, F. J., Lu, X. F., Luo, Q., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Shang, R. C., Song, X. Y., Sun, L., Tan, Y., Wang, C., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, J. W., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y. F., Zhang, Y. J., Zhang, Y. H., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., Zhou, D. K., Zhou, J. F., Zhu, Y. X., Zhu, Y., and Zhuang, R. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We use the In data collected during the 2019 outburst from X-ray pulsar 4U 1901+03 to complement the orbital parameters reported by Fermi/GBM. Using the Insight-HXMT, we examine the correlation between the derivative of the intrinsic spin frequency and bolometric flux based on accretion torque models. It was found that the pulse profiles significantly evolve during the outburst. The existence of two types of the profile's pattern discovered in the Insight-HXMT data indicates that this source experienced transition between a super-critical and a sub-critical accretion regime during its 2019 outburst. Based on the evolution of the pulse profiles and the torque model, we derive the distance to 4U 1901+03 as 12.4+-0.2 kpc., Comment: 8 pages, 5 figures, accepted by JHEAP
Published: 2020

27. The evolution of the broadband temporal features observed in the black-hole transient MAXI J1820+070 with Insight-HXMT

Author: Wang, Yanan, Ji, Long, Zhang, S. N., Méndez, Mariano, Qu, J. L., Maggi, Pierre, Ge, M. Y., Qiao, Erlin, Tao, L., Zhang, S., Altamirano, Diego, Zhang, L., Ma, X., Lu, F. J., Li, T. P., Huang, Y., Zheng, S. J., Chen, Y. P., Chang, Z., Tuo, Y. L., Gungor, C., Song, L. M., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Bu, Q. C., Cai, C., Chen, G., Chen, L., Chen, T. X., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Shang, R. C., Song, X. Y., Sun, L., Tan, Y., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. D., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, J. W., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W. C., Zhang, W., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zhou, D. K., Zhou, J. F., Zhuang, R. L., Zhu, Y. X., and Zhu, Y.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We study the evolution of the temporal properties of MAXI 1820+070 during the 2018 outburst in its hard state from MJD 58190 to 58289 with Insight-HXMT in a broad energy band 1-150 keV. We find different behaviors of the hardness ratio, the fractional rms and time lag before and after MJD 58257, suggesting a transition occurred at around this point. The observed time lags between the soft photons in the 1-5 keV band and the hard photons in higher energy bands, up to 150 keV, are frequency-dependent: the time lags in the low-frequency range, 2-10 mHz, are both soft and hard lags with a timescale of dozens of seconds but without a clear trend along the outburst; the time lags in the high-frequency range, 1-10 Hz, are only hard lags with a timescale of tens of milliseconds; first increase until around MJD 58257 and decrease after this date. The high-frequency time lags are significantly correlated to the photon index derived from the fit to the quasi-simultaneous NICER spectrum in the 1-10 keV band. This result is qualitatively consistent with a model in which the high-frequency time lags are produced by Comptonization in a jet., Comment: Accepted for publication in ApJ
Published: 2020
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28. Discovery of delayed spin-up behavior following two large glitches in the Crab pulsar, and the statistics of such processes

Author: Ge, M. Y., Zhang, S. N., Lu, F. J., Li, T. P., Yuan, J. P., Zheng, X. P., Huang, Y., Zheng, S. J., Chen, Y. P., Chang, Z., Tuo, Y. L., Cheng, Q., Güngör, C., Song, L. M., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Zhang, S., Qu, J. L., Bu, Q. C., Cai, C., Chen, G., Chen, L., Chen, M. Z., Chen, T. X., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Hao, L. F., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, C. J., Jin, J., Jin, Y. J., Kong, L. D., Li, B., Li, D., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Li, Z. X., Liu, Z. Y., Liang, X. H., Liao, J. Y., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Shang, R. C., Song, X. Y., Sun, L., Tan, Y., Tao, L., Wang, C., Wang, G. F., Wang, J., Wang, J. B., Wang, M., Wang, N., Wang, W. S., Wang, Y. D., Wang, Y. S., Wen, X. Y., Wen, Z. G., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Xu, Y. H., Yan, W. M., Yang, J. W., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Yue, Y. L., Zhang, A. M., Zhang, C. M., Zhang, D. P., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W. C., Zhang, W., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, W., Zhou, D. K., Zhou, J. F., Zhou, X., Zhuang, R. L., Zhu, Y. X., and Zhu, Y.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Glitches correspond to sudden jumps of rotation frequency ($\nu$) and its derivative ($\dot{\nu}$) of pulsars, the origin of which remains not well understood yet, partly because the jump processes of most glitches are not well time-resolved. There are three large glitches of the Crab pulsar, detected in 1989, 1996 and 2017, which were found to have delayed spin-up processes before the normal recovery processes. Here we report two additional glitches of the Crab pulsar occurred in 2004 and 2011 for which we discovered delayed spin up processes, and present refined parameters of the largest glitch occurred in 2017. The initial rising time of the glitch is determined as $<0.48$ hour. We also carried out a statistical study of these five glitches with observed spin-up processes. The two glitches occurred in 2004 and 2011 have delayed spin-up time scales ($\tau_{1}$) of $1.7\pm0.8$\,days and $1.6\pm0.4$\,days, respectively. We find that the $\Delta{\nu}$ vs. $|\Delta{\dot\nu}|$ relation of these five glitches is similar to those with no detected delayed spin-up process, indicating that they are similar to the others in nature except that they have larger amplitudes. For these five glitches, the amplitudes of the delayed spin-up process ($|\Delta{\nu}_{\rm d1}|$) and recovery process ($\Delta{\nu}_{\rm d2}$), their time scales ($\tau_{1}$, $\tau_{2}$), and permanent changes in spin frequency ($\Delta{\nu}_{\rm p}$) and total frequency step ($\Delta{\nu}_{\rm g}$) have positive correlations. From these correlations, we suggest that the delayed spin-up processes are common for all glitches, but are too short and thus difficult to be detected for most glitches., Comment: 25 pages, 8 figures
Published: 2020
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29. A search for prompt gamma-ray counterparts to fast radio bursts in the Insight-HXMT data

Author: Guidorzi, C., Marongiu, M., Martone, R., Nicastro, L., Xiong, S. L., Liao, J. Y., Li, G., Zhang, S. N., Amati, L., Frontera, F., Orlandini, M., Rosati, P., Virgilli, E., Zhang, S., Bu, Q. C., Cai, C., Cao, X. L., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Ge, M. Y., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Kong, L. D., Li, B., Li, C. K., Li, M. S., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liu, B. S., Liu, C. Z., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, F. J., Lu, X. F., Luo, Q., Luo, T., Ma, R. C., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Oui, G., Qu, J. L, Sai, N., Shang, R. C., Song, L. M., Song, X. Y., Sun, L., Tani, Y., Tao, L., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xu, Y. P., Yang, J. W., Yang, S., Yang, Y. J., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M. Zhang C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W. C., Zhang, W., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhang, H. S., Zhang, X. F., Zheng, S. J., Zhou, D. K., Zhou, J. F., Zhu, Y. X., Zhu, Y., and Zhuang, R. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: No robust detection of prompt electromagnetic counterparts to fast radio bursts (FRBs) has yet been obtained, in spite of several multi-wavelength searches carried out so far. Specifically, X/gamma-ray counterparts are predicted by some models. We planned on searching for prompt gamma-ray counterparts in the Insight-Hard X-ray Modulation Telescope (Insight-HXMT) data, taking advantage of the unique combination of large effective area in the keV-MeV energy range and of sub-ms time resolution. We selected 39 FRBs that were promptly visible from the High-Energy (HE) instrument aboard Insight-HXMT. After calculating the expected arrival times at the location of the spacecraft, we searched for a significant excess in both individual and cumulative time profiles over a wide range of time resolutions, from several seconds down to sub-ms scales. Using the dispersion measures in excess of the Galactic terms, we estimated the upper limits on the redshifts. No convincing signal was found and for each FRB we constrained the gamma-ray isotropic-equivalent luminosity and the released energy as a function of emission timescale. For the nearest FRB source, the periodic repeater FRB180916.J0158+65, we find $L_{\gamma,iso}<5.5\times 10^{47}$ erg/s over 1 s, whereas $L_{\gamma,iso}<10^{49}-10^{51}$ erg/s for the bulk of FRBs. The same values scale up by a factor of ~100 for a ms-long emission. Even on a timescale comparable with that of the radio pulse itself no keV-MeV emission is observed. A systematic association with either long or short GRBs is ruled out with high confidence, except for subluminous events, as is the case for core-collapse of massive stars (long) or binary neutron star mergers (short) viewed off axis. Only giant flares from extra-galactic magnetars at least ten times more energetic than Galactic siblings are ruled out for the nearest FRB., Comment: 15 pages, 3 figures, 6 tables, accepted by A&A
Published: 2020
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30. Switches between accretion structures during flares in 4U 1901+03

Author: Ji, L., Ducci, L., Santangelo, A., Zhang, S., Suleimanov, V., Tsygankov, S., Doroshenko, V., Nabizadeh, A., Zhang, S. N., Ge, M. Y., Tao, L., Bu, Q. C., Qu, J. L., Lu, F. J., Chen, L., Song, L. M., Li, T. P., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Cai, C., Chang, Z., Chen, G., Chen, T. X., Chen, Y. B., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, G. Q., Liu, H. X., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Ren, X. Q., Sai, N., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, J. W., Yang, S., Yang, Yan-Ji, Yang, Yi-Jung, Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, P., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Yi, Zhang, Y. F., Zhang, Y. J., Zhang, Y. H., Zhang, Yue, Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zhou, D. K., Zhou, J. F., Zhu, Y. X., and Zhu, Y.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on our analysis of the 2019 outburst of the X-ray accreting pulsar 4U 1901+03 observed with Insight-HXMT and NICER. Both spectra and pulse profiles evolve significantly in the decaying phase of the outburst. Dozens of flares are observed throughout the outburst. They are more frequent and brighter at the outburst peak. We find that the flares, which have a duration from tens to hundreds of seconds, are generally brighter than the persistent emission by a factor of $\sim$ 1.5. The pulse profile shape during the flares can be significantly different than that of the persistent emission. In particular, a phase shift is clearly observed in many cases. We interpret these findings as direct evidence of changes of the pulsed beam pattern, due to transitions between the sub- and super-critical accretion regimes on a short time scale. We also observe that at comparable luminosities the flares' pulse profiles are rather similar to those of the persistent emission. This indicates that the accretion on the polar cap of the neutron star is mainly determined by the luminosity, i.e., the mass accretion rate., Comment: 11 pages, 8 figures, accepted for publication in MNRAS
Published: 2020
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31. Joint Analysis of Energy and RMS Spectra from MAXI J1535-571 with Insight-HXMT

Author: Kong, L. D., Zhang, S., Chen, Y. P., Ji, L., Zhang, S. N., Yang, Y. R., Tao, L., Ma, X., Qu, J. L., Lu, F. J., Bu, Q. C., Chen, L., Song, L. M., Li, T. P., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Cai, C., Chang, Z., Chen, G., Chen, T. X., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Ge, M. Y., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, G. Q., Liu, H. X., Liu, H. W., Liu, S. Z., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Ren, X. Q., Sai, N., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, P. J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Xu, H., Yang, J. W., Yang, S., Yang, Y. J., Yi, Q. B., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, P., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Y. H., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zheng, Y. G., Zhou, D. K., Zhou, J. F., Zhu, Y. X., and Zhu, Y.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: A new black hole X-ray binary (BHXRB) MAXI J1535-571 was discovered by MAXI during its outburst in 2017. Using observations taken by the first Chinese X-ray satellite, the Hard X-ray Modulation Telescope (dubbed as Insight-HXMT), we perform a joint spectral analysis (2-150 keV) in both energy and time domains. The energy spectra provide the essential input for probing the intrinsic Quasi-Periodic Oscillation (QPO) fractional rms spectra (FRS). Our results show that during the intermediate state, the energy spectra are in general consistent with those reported by Swift/XRT and NuSTAR. However, the QPO FRS become harder and the FRS residuals may suggest the presence of either an additional power-law component in the energy spectrum or a turn-over in the intrinsic QPO FRS at high energies.
Published: 2020

32. Diagnostic of the spectral properties of Aquila X-1 by Insight-HXMT snapshots during the early propeller phase

Author: Güngör, C., Ge, M. Y., Zhang, S., Santangelo, A., Zhang, S. N., Lu, F. J., Zhang, Y., Chen, Y. P., Tao, L., Yang, Y. J., Bu, Q. C., Cai, C., Cao, X. L., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Ji, L., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, C. Z., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, T., Luo, Q., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Song, L. M., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Xu, Y. P., Yang, J. W., Yang, S., Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zhou, D. K., Zhou, J. F., Zhu, Y., and Zhu, Y. X.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We study the 2018 outburst of Aql X-1 via the monitor of all sky X-ray image (MAXI) data. We show that the outburst starting in February 2018 is a member of short-low class in the frame of outburst duration and the peak count rate although the outburst morphology is slightly different from the other fast-rise-exponential-decay (FRED) type outbursts with a milder rising stage. We study the partial accretion in the weak propeller stage of Aql X-1 via the MAXI data of the 2018 outburst. We report on the spectral analysis of 3 observations of Aquila X-1 obtained by Insight - hard X-ray modulation telescope (Insight-HXMT) during the late decay stage of the 2018 outburst. We discuss that the data taken by Insight-HXMT is just after the transition to the weak propeller stage. Our analysis shows the necessity of a comptonization component to take into account the existence of an electron cloud resulting photons partly up-scattered., Comment: 8 pages, 4 figures, accepted for publication in JHEAp
Published: 2019

33. $Insight$-HXMT study of the timing properties of Sco X-1

Author: Jia, S. M., Bu, Q. C., Qu, J. L., Lu, F. J., Zhang, S. N., Huang, Y., Ma, X., Tao, L., Xiao, G. C., Zhang, W., Chen, L., Song, L. M., Zhang, S., Li, T. B., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Cai, C., Chang, Z., Chen, G., Chen, T. X., Chen, Y. B., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Ge, M. Y., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huo, J., Jiang, L. H., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Song, X. Y., Sun, L., Tan, Y., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, S., Xiong, S. L., Yang, J. W., Yang, S., Yang, Y. J., Yin, Q. Q., Yi, Q. B., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zhou, D. K., Zhou, J. F., Zhu, Y. X., and Zhu, Y.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract: We present a detailed timing study of the brightest persistent X-ray source Sco X-1 using the data collected by the Hard X-ray Modulation Telescope ($Insight$-HXMT) from July 2017 to August 2018. A complete $Z$-track hardness-intensity diagram (HID) is obtained. The normal branch oscillations (NBOs) at $\sim$ 6 Hz in the lower part of the normal branch (NB) and the flare branch oscillations (FBOs) at $\sim$ 16 Hz in the beginning part of the flaring branch (FB) are found in observations with the Low Energy X-ray Telescope (LE) and the Medium Energy X-ray Telescope (ME) of $Insight$-HXMT, while the horizontal branch oscillations (HBOs) at $\sim$ 40 Hz and the kilohertz quasi-periodic oscillations (kHz QPOs) at $\sim$ 800 Hz are found simultaneously up to 60 keV for the first time on the horizontal branch (HB) by the High Energy X-ray Telescope (HE) and ME. We find that for all types of the observed QPOs, the centroid frequencies are independent of energy, while the root mean square (rms) increases with energy; the centroid frequencies of both the HBOs and kHz QPOs increase along the $Z$-track from the top to the bottom of the HB; and the NBOs show soft phase lags increasing with energy. A continuous QPO transition from the FB to NB in $\sim$ 200 s are also detected. Our results indicate that the non-thermal emission is the origin of all types of QPOs, the innermost region of the accretion disk is non-thermal in nature, and the corona is nonhomogeneous geometrically.
Published: 2019

34. Insight-HXMT observation on 4U~1608--52: evolving spectral properties of a bright type-I X-ray burst

Author: Chen, Y. P., Zhang, S., Zhang, S. N., Ji, L., Kong, L. D., Santangelo, A., Qu, J. L., Lu, F. J., Li, T. P., Song, L. M., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Bu, Q. C., Cai, C., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Ge, M. Y., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liu, J. Y. Liao G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Sun, L., Tan, Y., Tao, L., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiao, S., Xiong, S. L., Yang, J. W., Yang, S., Yang, Yang-Ji, Yang, Yi-Jung, Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. L., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W. C., Zhang, W., Zhang, W. Z., Zhang, Yi., Zhang, Y. F., Zhang, Y. J., Zhang, Yue., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zhou, D. K., Zhou, J. F., Zhu, Y., and Zhu, Y. X.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The evidences for the influence of thermonuclear (type-I) X-ray bursts upon the surrounding environments in neutron star low-mass X-ray binaries (LMXB) were detected previously via spectral and timing analyses. Benefitting from a broad energy coverage of Insight-HXMT, we analyze one photospheric radius expansion (PRE) burst, and find an emission excess at soft X-rays. Our spectral analysis shows that, such an excess is not likely relevant to the disk reflection induced by the burst emission and can be attributed to an enhanced pre-burst/persistent emission. We find that the burst and enhanced persistent emissions sum up to exceed Eddington luminosity by $\sim$ 40 percentages. We speculate that the enhanced emission is from a region beyond the PRE radius, or through the Comptonization of the corona., Comment: accepted by JHEA(Journal of High Energy Astrophysics)
Published: 2019

35. Insight-HXMT observations of 4U~1636-536: Corona cooling revealed with single short type-I X-ray burst

Author: Chen, Y. P., Zhang, S., Zhang, S. N., Ji, L., Kong, L. D., Cao, X. L., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Ge, M. Y., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Hu, W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Li, B., Li, C. K., Li, G., Li, M. S., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. J., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, C. Z., Liu, G. Q., Liu, H. W., Liu, S. Z., Liu, X. J., Liu, Y., Liu, Y. N., Lu, B., Lu, F. J., Lu, X. F., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Qu, J. L., Sai, N., Song, L. M., Sun, L., Tan, Y., Tao, L., Tao, W. H., Tuo, Y. L., Wang, G. F., Wang, H. Y., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiong, S. L., Xu, H., Xu, Y. P., Yan, L. L., Yang, J. W., Yang, S., Yang, Y. J., Zhang, A. M., Zhang, C. L., Zhang, C. M., Zhang, F., hang, H. M., Zhang, J., Zhang, Q., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, J. L., Zhao, X. F., Zheng, S. J., Zhu, Y., Zhu, Y. X., and Zou, C. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Corona cooling was detected previously from stacking a series of short type-I bursts occurred during the low/had state of atoll outburst. Type-I bursts are hence regarded as sharp probe to our better understanding on the basic property of the corona. The launch of the first Chinese X-ray satellite Insight-HXMT has large detection area at hard X-rays which provide almost unique chance to move further in this research field. We report the first detection of the corona cooling by Insight-HXMT from single short type-I burst showing up during {\bf flare} of 4U 1636-536. This type-I X-ray burst has a duration of $\sim$13 seconds and hard X-ray shortage is detected with significance 6.2~$\sigma$ in 40-70 keV. A cross-correlation analysis between the lightcurves of soft and hard X-ray band, shows that the corona shortage lag the burst emission by 1.6 $\pm$1.2~s. These results are consistent with those derived previously from stacking a large amount of bursts detected by RXTE/PCA within a series of {\bf flares} of 4U 1636-536. Moreover, the broad bandwidth of Insight-HXMT allows as well for the first time to infer the burst influence upon the continuum spectrum via performing the spectral fitting of the burst, which ends up with the finding that hard X-ray shortage appears at around 40 keV in the continuum spectrum. These results suggest that the evolution of the corona along with the outburst{\bf /flare} of NS XRB may be traced via looking into a series of embedded type-I bursts by using Insight-HXMT., Comment: published in 2018, ApJL,864, L30
Published: 2019
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36. The Insight-HXMT mission and its recent progresses

Author: Zhang, S., Zhang, S. N., Lu, F. J., Li, T. P., Song, L. M., Xu, Y. P., Wang, H. Y., Qu, J. L., Liu, C. Z., Chen, Y., Cao, X. L., Zhang, F., Xiong, S. L., Ge, M. Y., Chen, Y. P., Liao, J. Y., Nie, J. Y., Zhao, H. S., Jia, S. M., Li, X. B., Guan, J., Li, C. K., Zhang, J., Jin, J., Wang, G. F., Zheng, S. J., Ma, X., Tao, L., and Huang, Y.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The Hard X-ray Modulation Telescope HXMT or also dubbed as Insight HXMT is China s first astronomical satellite . It was launched on 15 th June 2017 in JiuQuan, China and is currently in service smoothly. It was designed to perform point ing , scan ning and gamma ray burst (GRB) observations and , based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we introduce the mission and its progresses in aspects of payload, core sciences, ground calibration/facility , ground segment, data archive, software, in orbit performance, calibration, background model, observations and preliminary results ., Comment: published in Proceedings of the SPIE, Volume 10699, id. 106991U 22 pp. (2018)
Published: 2019
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37. Timing analysis of 2S 1417-624 observed with NICER and Insight-HXMT

Author: Ji, L., Doroshenko, V., Santangelo, A., Gungor, C., Zhang, S., Ducci, L., Zhang, S. -N., Ge, M. -Y., Qu, L. J., Chen, Y. P., Bu, Q. C., Cao, X. L., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Hu, W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. J., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, C. Z., Liu, G. Q., Liu, H. W., Liu, S. Z., Liu, X. J., Liu, Y., Liu, Y. N., Lu, B., Lu, F. J., Lu, X. F., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Song, L. M., Song, X. Y., Sun, L., Tan, Y., Tao, L., Tuo, Y. L., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiong, S. L., Xu, H., Xu, Y. P., Yang, Y. R., Yang, J. W., Yang, S., Yang, Y. J., Zhang, A. M., Zhang, C. L., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, Q., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, J. L., Zhao, X. F., Zheng, S. J., Zhu, Y., Zhu, Y. X., and Zou, C. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present a study of timing properties of the accreting pulsar 2S 1417-624 observed during its 2018 outburst, based on Swift/BAT, Fermi/GBM, Insight-HXMT and NICER observations. We report a dramatic change of the pulse profiles with luminosity. The morphology of the profile in the range 0.2-10.0keV switches from double to triple peaks at $\sim2.5$ $\rm \times 10^{37}{\it D}_{10}^2\ erg\ s^{-1}$ and from triple to quadruple peaks at $\sim7$ $\rm \times 10^{37}{\it D}_{10}^2\ erg\ s^{-1}$. The profile at high energies (25-100keV) shows significant evolutions as well. We explain this phenomenon according to existing theoretical models. We argue that the first change is related to the transition from the sub to the super-critical accretion regime, while the second to the transition of the accretion disc from the gas-dominated to the radiation pressure-dominated state. Considering the spin-up as well due to the accretion torque, this interpretation allows to estimate the magnetic field self-consistently at $\sim7\times 10^{12}$G., Comment: 7 pages, 4 figures, 1 tables, accepted for publication in MNRAS
Published: 2019
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38. Constant cyclotron line energy in Hercules X-1 -- Joint Insight-HXMT and NuSTAR observations

Author: Xiao, G. C., Ji, L., Staubert, R., Ge, M. Y., Zhang, S., Zhang, S. N., Santangelo, A., Ducci, L., Liao, J. Y., Guo, C. C., Li, X. B., Zhang, W., Qu, J. L., Lu, F. J., Li, T. P., Song, L. M., Xu, Y. P., Bu, Q. C., Cai, C., Cao, X. L., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Gungor, C., Han, D. W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liu, C. Z., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, Q., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Song, S. X., Sun, L., Tan, Y., Tao, L., Tuo, Y. L., Wang, C., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiong, S. L., Yang, J. W., Yang, S., Yang, Y. J., Yin, Q. B., Yin, Q. Q., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, X. F., Zheng, S. J., Zhou, J. F., Zhu, Y., and Zhu, Y. X.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The long-term evolution of the centroid energy of the CRSF in Her X-1 is still a mystery. We report a new measurement from a campaign between {\sl Insight}-HXMT and {\sl NuSTAR} performed in February 2018. Generally, the two satellites show well consistent results of timing and spectral properties. The joint spectral analysis confirms that the previously observed long decay phase has ended, and that the line energy instead keeps constant around 37.5 keV after flux correction.
Published: 2019

39. Hot disk of the Swift J0243.6+6124 revealed by Insight-HXMT

Author: Doroshenko, V., Zhang, S. N., Santangelo, A., Ji, L., Tsygankov, S., Mushtukov, A., Qu, L. J., Zhang, S., Ge, M. Y., Chen, Y. P., Bu, Q. C., Cao, X. L., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, Guo, C. C., Han, D. W., Hu, W., Huang, Y., Huo, J., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Kong, L. D., Li, B., Li, C. K., Li, G., Li, M. S., Li, T. P., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. J., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, C. Z., Liu, G. Q., Liu, H. W., Liu, S. Z., Liu, X. J., Liu, Y., Liu, Y. N., Lu, B., Lu, F. J., Lu, X. F., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G., Sai, N., Song, L. M., Song, X. Y., Sun, L., Tan, Y., Tao, L., Tuo, Y. L., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiong, S. L., Xu, H., Xu, Y. P., Yang, Y. R., Yang, J. W., Yang, S., Yang, Y. J., Zhang, A. M., Zhang, C. L., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, Q., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, J. L., Zhao, X. F., Zheng, S. J., Zhu, Y., Zhu, Y. X., and Zou, C. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We report on analysis of observations of the bright transient X-ray pulsar \src obtained during its 2017-2018 giant outburst with Insight-HXMT, \emph{NuSTAR}, and \textit{Swift} observatories. We focus on the discovery of a sharp state transition of the timing and spectral properties of the source at super-Eddington accretion rates, which we associate with the transition of the accretion disk to a radiation pressure dominated (RPD) state, the first ever directly observed for magnetized neutron star. This transition occurs at slightly higher luminosity compared to already reported transition of the source from sub- to super-critical accretion regime associate with onset of an accretion column. We argue that this scenario can only be realized for comparatively weakly magnetized neutron star, not dissimilar to other ultra-luminous X-ray pulsars (ULPs), which accrete at similar rates. Further evidence for this conclusion is provided by the non-detection of the transition to the propeller state in quiescence which strongly implies compact magnetosphere and thus rules out magnetar-like fields., Comment: Submitted to MNRAS
Published: 2019
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40. In-orbit demonstration of X-ray pulsar navigation with the Insight-HXMT satellite

Author: Zheng, S. J., Zhang, S. N., Lu, F. J., Wang, W. B., Gao, Y., Li, T. P., Song, L. M., Ge, M. Y., Han, D. W., Chen, Y., Xu, Y. P., Cao, X. L., Liu, C. Z., Zhang, S., Qu, J. L., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Gungor, C., Guo, C. C., Hu, W., Huang, Y., Huo, J., Ji, J. F., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. J., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, G. Q., Liu, H. W., Liu, S. Z., Liu, X. J., Liu, Y., Liu, Y. N., Lu, B., Lu, X. F., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G, Sai, N., Shang, R. C., Sun, L., Tan, Y., Tao, L., Tao, W., Tuo, Y. L., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiong, S. L., Xu, H., Yan, L. L., Yang, J. W., Yang, S., Yang, Y. J., Zhang, A. M., Zhang, C. L., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, Q., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, J. L., Zhao, X. F., Zhu, Y., Zhu, Y. X., and Zou, C. L.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: In this work, we report the in-orbit demonstration of X-ray pulsar navigation with Insight-Hard X-ray Modulation Telescope (Insight-HXMT), which was launched on Jun. 15th, 2017. The new pulsar navigation method 'Significance Enhancement of Pulse-profile with Orbit-dynamics' (SEPO) is adopted to determine the orbit with observations of only one pulsar. In this test, the Crab pulsar is chosen and observed by Insight-HXMT from Aug. 31th to Sept. 5th in 2017. Using the 5-day-long observation data, the orbit of Insight-HXMT is determined successfully with the three telescopes onboard - High Energy X-ray Telescope (HE), Medium Energy X-ray Telescope (ME) and Low Energy X-ray Telescope (LE) - respectively. Combining all the data, the position and velocity of the Insight-HXMT are pinpointed to within 10 km (3 sigma) and 10 m/s (3 sigma), respectively., Comment: Accepted by the Astrophysical Journal Supplement
Published: 2019
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41. Solidification behavior and environmental risk assessment of toxic elements on tailings from carbothermic reduction-magnetic separation of lead blast furnace slag

Author: Jiang Z.-W., Li M.-T., Wei C., Cao Y.-L., Li X.-B., and Deng Z.-G.
Subjects: lead blast furnace slag, environmental risk, potentially toxic elements, carbothermic reduction, magnetic separation, leaching toxicity, Mining engineering. Metallurgy, TN1-997
Abstract: Lead blast furnace slag (LBFS) generated during lead smelting is a hazardous solid waste containing potentially toxic elements (Pb, Zn, As, and Cd) with high mobility and solubility. In this study, a process for the utilization of LBFS by carbothermic reduction-magnetic separation method is proposed. Leaching toxicity and Tessier sequential extraction experiments were conducted on LBFS and magnetic separation tailings (TS), and the environmental risk was evaluated using the risk assessment coding index and potential ecological risk index. The obtained results showed that the potentially toxic elements in the TS were solidified in the spinel phase or silicate phase. In addition, the XRD, SEM-EDS, and FTIR results showed the formation of PbCa2Si3O9, ZnAl2O4, and Ca3(AsO4)2 phases. The leaching concentrations of Pb, Zn, As, and Cd in TS were much lower than the toxicity characteristic leaching procedure (TCLP) and China standard leaching test (CSLT) limits. The results of Tessier sequential extraction procedure confirmed that the proportions of the stable residual state of the potentially toxic elements in TS were significantly higher than in LBFS. Furthermore, the ecological environmental risk level for the TS decreased significantly compared to that of LBFS.
Published: 2023
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42. Insight-HXMT observations of the New Black Hole Candidate MAXI J1535-571: timing analysis

Author: Huang, Y., Qu, J. L., Zhang, S. N., Bu, Q. C., Chen, Y. P., Tao, L., Zhang, S., Lu, F. J., Li, T. P., Song, L. M., Xu, Y. P., Cao, X. L., Chen, Y., Liu, C. Z., Chang, H. -K., Yu, W. f., Weng, S. S., Hou, X., Kong, A. K. H., Xie, F. G., Zhang, G. B., ZHOU, J. F., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y. B., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Ge, M. Y., Gu, Y. D., Guan, J., Gungor, C., Guo, C. C., Han, D. W., Hu, W., Huo, J., Ji, J. F., Jia, S. M., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Li, B., Li, C. K., Li, G., Li, M. S., Li, W., Li, X., Li, X. B., Li, X. F., Li, Y. G., Li, Z. J., Li, Z. W., Liang, X. H., Liao, J. Y., Liu, G. Q., Liu, H. W., Liu, S. Z., Liu, X. J., Liu, Y., Liu, Y. N., Lu, B., Lu, X. F., Luo, T., Ma, X., Meng, B., Nang, Y., Nie, J. Y., Ou, G, Sai, N., Shang, R. C., Sun, L., Tan, Y., Tao, W., Tuo, Y. L., Wang, G. F., Wang, H. Y., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, M., Xiao, G. C., Xiong, S. L., Xu, H., Yan, L. L., Yang, J. W., Yang, S., Yang, Y. J., Zhang, A. M., Zhang, C. L., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, Q., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Z. L., Zhao, H. S., Zhao, J. L., Zhao, X. F., Zheng, S. J., Zhu, Y., Zhu, Y. X., and Zou, C. L.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We present the X-ray timing results of the new black hole candidate (BHC) MAXI J1535-571 during its 2017 outburst from Hard X-ray Modulation Telescope (\emph{Insight}-HXMT) observations taken from 2017 September 6 to 23. Following the definitions given by \citet{Belloni2010}, we find that the source exhibits state transitions from Low/Hard state (LHS) to Hard Intermediate state (HIMS) and eventually to Soft Intermediate state (SIMS). Quasi-periodic oscillations (QPOs) are found in the intermediate states, which suggest different types of QPOs. With the large effective area of \emph{Insight}-HXMT at high energies, we are able to present the energy dependence of the QPO amplitude and centroid frequency up to 100 keV which is rarely explored by previous satellites. We also find that the phase lag at the type-C QPOs centroid frequency is negative (soft lags) and strongly correlated with the centroid frequency. By assuming a geometrical origin of type-C QPOs, the source is consistent with being a high inclination system., Comment: 12 pages, 11 figures, Sumbitted to ApJ
Published: 2018
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43. Recovery of zinc from zinc oxide dust containing multiple metal elements by carbothermal reduction

Author: Lei F.-G., Li M.-T., Wei C., Deng Z.-G., Li X.-B., and Fan G.
Subjects: zinc oxide dust, carbothermal reduction, volatilization, condensation, recovery, Mining engineering. Metallurgy, TN1-997
Abstract: A carbothermal reduction process simulating EAF process is used to handle the zinc oxide dust, and the zinc in the dust can be extracted and recovered efficiently. The crude zinc and lead-tin alloy were obtained finally. The effects of temperature, holding time, and reductant dosage on zinc volatilization rate were investigated, and the “Pelletizing - Calcination- Carbothermic reduction” experiment was conducted. The results found the optimal reduction condition was as follows: the temperature of 1300℃, reductant dosage of 14.04%, and holding time of 120 min. After the calcination at 900℃ for 120 min, the removal rates of fluorine, chlorine, and sulfur in the dust were 98.18%, 96.38% and 28.58% respectively, and the volatilization rate of zinc was 99.83% in the reduction process. The zinc content of the crude zinc was 68.48%.
Published: 2022
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44. The Detector System of The Daya Bay Reactor Neutrino Experiment

Author: An, F. P., Bai, J. Z., Balantekin, A. B., Band, H. R., Beavis, D., Beriguete, W., Bishai, M., Blyth, S., Brown, R. L., Butorov, I., Cao, D., Cao, G. F., Cao, J., Carr, R., Cen, W. R., Chan, W. T., Chan, Y. L., Chang, J. F., Chang, L. C., Chang, Y., Chasman, C., Chen, H. Y., Chen, H. S., Chen, M. J., Chen, Q. Y., Chen, S. J., Chen, S. M., Chen, X. C., Chen, X. H., Chen, X. S., Chen, Y. X., Chen, Y., Cheng, J. H., Cheng, J., Cheng, Y. P., Cherwinka, J. J., Chidzik, S., Chow, K., Chu, M. C., Cummings, J. P., de Arcos, J., Deng, Z. Y., Ding, X. F., Ding, Y. Y., Diwan, M. V., Dong, L., Dove, J., Draeger, E., Du, X. F., Dwyer, D. A., Edwards, W. R., Ely, S. R., Fang, S. D., Fu, J. Y., Fu, Z. W., Ge, L. Q., Ghazikhanian, V., Gill, R., Goett, J., Gonchar, M., Gong, G. H., Gong, H., Gornushkin, Y. A., Grassi, M., Greenler, L. S., Gu, W. Q., Guan, M. Y., Guo, R. P., Guo, X. H., Hackenburg, R. W., Hahn, R. L., Han, R., Hans, S., He, M., He, Q., He, W. S., Heeger, K. M., Heng, Y. K., Higuera, A., Hinrichs, P., Ho, T. H., Hoff, M., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, L. M., Hu, L. J., Hu, T., Hu, W., Huang, E. C., Huang, H. Z., Huang, H. X., Huang, P. W., Huang, X., Huang, X. T., Huber, P., Hussain, G., Isvan, Z., Jaffe, D. E., Jaffke, P., Jen, K. L., Jetter, S., Ji, X. P., Ji, X. L., Jiang, H. J., Jiang, W. Q., Jiao, J. B., Johnson, R. A., Joseph, J., Kang, L., Kettell, S. H., Kohn, S., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Lai, C. Y., Lai, W. C., Lai, W. H., Langford, T. J., Lau, K., Lebanowski, L., Lee, J., Lee, M. K. P., Lei, R. T., Leitner, R., Leung, J. K. C., Leung, K. Y., Lewis, C. A., Li, B., Li, C., Li, D. J., Li, F., Li, G. S., Li, J., Li, N. Y., Li, Q. J., Li, S. F., Li, S. C., Li, W. D., Li, X. B., Li, X. N., Li, X. Q., Li, Y., Li, Y. F., Li, Z. B., Liang, H., Liang, J., Lin, C. J., Lin, G. L., Lin, P. Y., Lin, S. X., Lin, S. K., Lin, Y. C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, B. J., Liu, C., Liu, D. W., Liu, H., Liu, J. L., Liu, J. C., Liu, S., Liu, S. S., Liu, X., Liu, Y. B., Lu, C., Lu, H. Q., Lu, J. S., Luk, A., Luk, K. B., Luo, T., Luo, X. L., Ma, L. H., Ma, Q. M., Ma, X. Y., Ma, X. B., Ma, Y. Q., Mayes, B., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mitchell, I., Mohapatra, D., Kebwaro, J. Monari, Morgan, J. E., Nakajima, Y., Napolitano, J., Naumov, D., Naumova, E., Newsom, C., Ngai, H. Y., Ngai, W. K., Nie, Y. B., Ning, Z., Ochoa-Ricoux, J. P., Olshevskiy, A., Pagac, A., Pan, H. -R., Patton, S., Pearson, C., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, B., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Sands III, W. R., Seilhan, B., Shao, B. B., Shih, K., Song, W. Y., Steiner, H., Stoler, P., Stuart, M., Sun, G. X., Sun, J. L., Tagg, N., Tam, Y. H., Tanaka, H. K., Tang, W., Tang, X., Taychenachev, D., Themann, H., Torun, Y., Trentalange, S., Tsai, O., Tsang, K. V., Tsang, R. H. M., Tull, C. E., Tung, Y. C., Viaux, N., Viren, B., Virostek, S., Vorobel, V., Wang, C. H., Wang, L. S., Wang, L. Y., Wang, L. Z., Wang, M., Wang, N. Y., Wang, R. G., Wang, T., Wang, W., Wang, W. W., Wang, X. T., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Webber, D. M., Wei, H. Y., Wei, Y. D., Wen, L. J., Wenman, D. L., Whisnant, K., White, C. G., Whitehead, L., Whitten Jr., C. A., Wilhelmi, J., Wise, T., Wong, H. C., Wong, H. L. H., Wong, J., Wong, S. C. F., Worcester, E., Wu, F. F., Wu, Q., Xia, D. M., Xia, J. K., Xiang, S. T., Xiao, Q., Xing, Z. Z., Xu, G., Xu, J. Y., Xu, J. L., Xu, J., Xu, W., Xu, Y., Xue, T., Yan, J., Yang, C. G., Yang, L., Yang, M. S., Yang, M. T., Ye, M., Yeh, M., Yeh, Y. S., Yip, K., Young, B. L., Yu, G. Y., Yu, Z. Y., Zeng, S., Zhan, L., Zhang, C., Zhang, F. H., Zhang, H. H., Zhang, J. W., Zhang, K., Zhang, Q. X., Zhang, Q. M., Zhang, S. H., Zhang, X. T., Zhang, Y. C., Zhang, Y. H., Zhang, Y. M., Zhang, Y. X., Zhang, Z. J., Zhang, Z. Y., Zhang, Z. P., Zhao, J., Zhao, Q. W., Zhao, Y. F., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, N., Zhou, Z. Y., Zhuang, H. L., Zimmerman, S., and Zou, J. H.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract: The Daya Bay experiment was the first to report simultaneous measurements of reactor antineutrinos at multiple baselines leading to the discovery of $\bar{\nu}_e$ oscillations over km-baselines. Subsequent data has provided the world's most precise measurement of $\rm{sin}^22\theta_{13}$ and the effective mass splitting $\Delta m_{ee}^2$. The experiment is located in Daya Bay, China where the cluster of six nuclear reactors is among the world's most prolific sources of electron antineutrinos. Multiple antineutrino detectors are deployed in three underground water pools at different distances from the reactor cores to search for deviations in the antineutrino rate and energy spectrum due to neutrino mixing. Instrumented with photomultiplier tubes (PMTs), the water pools serve as shielding against natural radioactivity from the surrounding rock and provide efficient muon tagging. Arrays of resistive plate chambers over the top of each pool provide additional muon detection. The antineutrino detectors were specifically designed for measurements of the antineutrino flux with minimal systematic uncertainty. Relative detector efficiencies between the near and far detectors are known to better than 0.2%. With the unblinding of the final two detectors' baselines and target masses, a complete description and comparison of the eight antineutrino detectors can now be presented. This paper describes the Daya Bay detector systems, consisting of eight antineutrino detectors in three instrumented water pools in three underground halls, and their operation through the first year of eight detector data-taking., Comment: 52 pages, 51 figures
Published: 2015
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45. HXMT identification of a non-thermal X-ray burst from SGR J1935+2154 and with FRB 200428

Author: Li, C. K., Lin, L., Xiong, S. L., Ge, M. Y., Li, X. B., Li, T. P., Lu, F. J., Zhang, S. N., Tuo, Y. L., Nang, Y., Zhang, B., Xiao, S., Chen, Y., Song, L. M., Xu, Y. P., Liu, C. Z., Jia, S. M., Cao, X. L., Qu, J. L., Zhang, S., Gu, Y. D., Liao, J. Y., Zhao, X. F., Tan, Y., Nie, J. Y., Zhao, H. S., Zheng, S. J., Zheng, Y. G., Luo, Q., Cai, C., Li, B., Xue, W. C., Bu, Q. C., Chang, Z., Chen, G., Chen, L., Chen, T. X., Chen, Y. B., Chen, Y. P., Cui, W., Cui, W. W., Deng, J. K., Dong, Y. W., Du, Y. Y., Fu, M. X., Gao, G. H., Gao, H., Gao, M., Gu, Y. D., Guan, J., Guo, C. C., Han, D. W., Huang, Y., Huo, J., Jiang, L. H., Jiang, W. C., Jin, J., Jin, Y. J., Kong, L. D., Li, G., Li, M. S., Li, W., Li, X., Li, X. F., Li, Y. G., Li, Z. W., Liang, X. H., Liu, B. S., Liu, G. Q., Liu, H. W., Liu, X. J., Liu, Y. N., Lu, B., Lu, X. F., Luo, T., Ma, X., Meng, B., Ou, G., Sai, N., Shang, R. C., Song, X. Y., Sun, L., Tao, L., Wang, C., Wang, G. F., Wang, J., Wang, W. S., Wang, Y. S., Wen, X. Y., Wu, B. B., Wu, B. Y., Wu, M., Xiao, G. C., Xu, H., Yang, J. W., Yang, S., Yang, Y. J., Yang, Yi-Jung, Yi, Q. B., Yin, Q. Q., You, Y., Zhang, A. M., Zhang, C. M., Zhang, F., Zhang, H. M., Zhang, J., Zhang, T., Zhang, W., Zhang, W. C., Zhang, W. Z., Zhang, Y., Zhang, Yue, Zhang, Y. F., Zhang, Y. J., Zhang, Z., Zhang, Zhi, Zhang, Z. L., Zhou, D. K., Zhou, J. F., Zhu, Y., Zhu, Y. X., and Zhuang, R. L.
Published: 2021
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46. Ultrafast laser-induced black silicon, from micro-nanostructuring, infrared absorption mechanism, to high performance detecting devices

Author: Zhao, J.-H., Li, X.-B., Chen, Q.-D., Chen, Z.-G., and Sun, H.-B.
Published: 2020
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47. An Inventory and Seasonal Changes in the Recent Benthic Flora of Coral Reefs of Wuzhizhou Island, Haitang Bay, South China Sea (China)

Author: Li, X. B., Titlyanov, E. A., Titlyanova, T. V., Belous, O. S., Xia, J. Q., and Huang, H.
Published: 2020
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48. Improved Measurement of Electron Antineutrino Disappearance at Daya Bay

Author: Daya Bay Collaboration, An, F. P., An, Q., Bai, J. Z., Balantekin, A. B., Band, H. R., Beriguete, W., Bishai, M., Blyth, S., Brown, R. L., Cao, G. F., Cao, J., Carr, R., Chan, W. T., Chang, J. F., Chang, Y., Chasman, C., Chen, H. S., Chen, H. Y., Chen, S. J., Chen, S. M., Chen, X. C., Chen, X. H., Chen, X. S., Chen, Y., Chen, Y. X., Cherwinka, J. J., Chu, M. C., Cummings, J. P., Deng, Z. Y., Ding, Y. Y., Diwan, M. V., Draeger, E., Du, X. F., Dwyer, D., Edwards, W. R., Ely, S. R., Fang, S. D., Fu, J. Y., Fu, Z. W., Ge, L. Q., Gill, R. L., Gonchar, M., Gong, G. H., Gong, H., Gornushkin, Y. A., Gu, W. Q., Guan, M. Y., Guo, X. H., Hackenburg, R. W., Hahn, R. L., Hans, S., Hao, H. F., He, M., He, Q., Heeger, K. M., Heng, Y. K., Hinrichs, P., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, T., Huang, H. X., Huang, H. Z., Huang, X. T., Huber, P., Issakov, V., Isvan, Z., Jaffe, D. E., Jetter, S., Ji, X. L., Ji, X. P., Jiang, H. J., Jiao, J. B., Johnson, R. A., Kang, L., Kettell, S. H., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Lai, C. Y., Lai, W. C., Lai, W. H., Lau, K., Lebanowski, L., Lee, J., Lei, R. T., Leitner, R., Leung, J. K. C., Leung, K. Y., Lewis, C. A., Li, F., Li, G. S., Li, Q. J., Li, W. D., Li, X. B., Li, X. N., Li, X. Q., Li, Y., Li, Z. B., Liang, H., Lin, C. J., Lin, G. L., Lin, S. K., Lin, Y. C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, D. W., Liu, J. C., Liu, J. L., Liu, Y. B., Lu, C., Lu, H. Q., Luk, A., Luk, K. B., Ma, Q. M., Ma, X. B., Ma, X. Y., Ma, Y. Q., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mohapatra, D., Nakajima, Y., Napolitano, J., Naumov, D., Nemchenok, I., Ngai, H. Y., Ngai, W. K., Nie, Y. B., Ning, Z., Ochoa-Ricoux, J. P., Olshevski, A., Patton, S., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Ren, J., Rosero, R., Roskovec, B., Ruan, X. C., Shao, B. B., Shih, K., Steiner, H., Sun, G. X., Sun, J. L., Tagg, N., Tam, Y. H., Tanaka, H. K., Tang, X., Themann, H., Torun, Y., Trentalange, S., Tsai, O., Tsang, K. V., Tsang, R. H. M., Tull, C. E., Tung, Y. C., Viren, B., Vorobel, V., Wang, C. H., Wang, L. S., Wang, L. Y., Wang, L. Z., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Webber, D. M., Wei, H. Y., Wei, Y. D., Wen, L. J., Whisnant, K., White, C. G., Whitehead, L., Williamson, Y., Wise, T., Wong, H. L. H., Worcester, E. T., Wu, F. F., Wu, Q., Xi, J. B., Xia, D. M., Xing, Z. Z., Xu, J., Xu, J. L., Xu, Y., Xue, T., Yang, C. G., Yang, L., Ye, M., Yeh, M., Yeh, Y. S., Young, B. L., Yu, Z. Y., Zhan, L., Zhang, C., Zhang, F. H., Zhang, J. W., Zhang, Q. M., Zhang, S. H., Zhang, Y. C., Zhang, Y. H., Zhang, Y. X., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., Zhao, J., Zhao, Q. W., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, Z. Y., Zhuang, H. L., and Zou, J. H.
Subjects: High Energy Physics - Experiment, Nuclear Experiment
Abstract: We report an improved measurement of the neutrino mixing angle $\theta_{13}$ from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for $\sin^22\theta_{13}$ with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GW$_{\rm th}$ were detected in six antineutrino detectors deployed in two near (flux-weighted baselines of 470 m and 576 m) and one far (1648 m) underground experimental halls. Using 139 days of data, 28909 (205308) electron antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to the expected number of antineutrinos assuming no oscillations at the far hall is $0.944\pm 0.007({\rm stat.}) \pm 0.003({\rm syst.})$. An analysis of the relative rates in six detectors finds $\sin^22\theta_{13}=0.089\pm 0.010({\rm stat.})\pm0.005({\rm syst.})$ in a three-neutrino framework., Comment: 21 pages, 24 figures. Submitted to and accepted by Chinese Physics C. Two typos were corrected. Description improved
Published: 2012
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49. Observation of electron-antineutrino disappearance at Daya Bay

Author: An, F. P., Bai, J. Z., Balantekin, A. B., Band, H. R., Beavis, D., Beriguete, W., Bishai, M., Blyth, S., Boddy, K., Brown, R. L., Cai, B., Cao, G. F., Cao, J., Carr, R., Chan, W. T., Chang, J. F., Chang, Y., Chasman, C., Chen, H. S., Chen, H. Y., Chen, S. J., Chen, S. M., Chen, X. C., Chen, X. H., Chen, X. S., Chen, Y., Chen, Y. X., Cherwinka, J. J., Chu, M. C., Cummings, J. P., Deng, Z. Y., Ding, Y. Y., Diwan, M. V., Dong, L., Draeger, E., Du, X. F., Dwyer, D. A., Edwards, W. R., Ely, S. R., Fang, S. D., Fu, J. Y., Fu, Z. W., Ge, L. Q., Ghazikhanian, V., Gill, R. L., Goett, J., Gonchar, M., Gong, G. H., Gong, H., Gornushkin, Y. A., Greenler, L. S., Gu, W. Q., Guan, M. Y., Guo, X. H., Hackenburg, R. W., Hahn, R. L., Hans, S., He, M., He, Q., He, W. S., Heeger, K. M., Heng, Y. K., Hinrichs, P., Ho, T. H., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, T., Huang, H. X., Huang, H. Z., Huang, P. W., Huang, X., Huang, X. T., Huber, P., Isvan, Z., Jaffe, D. E., Jetter, S., Ji, X. L., Ji, X. P., Jiang, H. J., Jiang, W. Q., Jiao, J. B., Johnson, R. A., Kang, L., Kettell, S. H., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Lai, C. Y., Lai, W. C., Lai, W. H., Lau, K., Lebanowski, L., Lee, J., Lee, M. K. P., Leitner, R., Leung, J. K. C., Leung, K. Y., Lewis, C. A., Li, B., Li, F., Li, G. S., Li, J., Li, Q. J., Li, S. F., Li, W. D., Li, X. B., Li, X. N., Li, X. Q., Li, Y., Li, Z. B., Liang, H., Liang, J., Lin, C. J., Lin, G. L., Lin, S. K., Lin, S. X., Lin, Y. C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, B. J., Liu, C., Liu, D. W., Liu, H., Liu, J. C., Liu, J. L., Liu, S., Liu, X., Liu, Y. B., Lu, C., Lu, H. Q., Luk, A., Luk, K. B., Luo, T., Luo, X. L., Ma, L. H., Ma, Q. M., Ma, X. B., Ma, X. Y., Ma, Y. Q., Mayes, B., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mohapatra, D., Morgan, J. E., Nakajima, Y., Napolitano, J., Naumov, D., Nemchenok, I., Newsom, C., Ngai, H. Y., Ngai, W. K., Nie, Y. B., Ning, Z., Ochoa-Ricoux, J. P., Oh, D., Olshevski, A., Pagac, A., Patton, S., Pearson, C., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Raper, N., Rosero, R., Roskovec, B., Ruan, X. C., Seilhan, B., Shao, B. B., Shih, K., Steiner, H., Stoler, P., Sun, G. X., Sun, J. L., Tam, Y. H., Tanaka, H. K., Tang, X., Themann, H., Torun, Y., Trentalange, S., Tsai, O., Tsang, K. V., Tsang, R. H. M., Tull, C., Viren, B., Virostek, S., Vorobel, V., Wang, C. H., Wang, L. S., Wang, L. Y., Wang, L. Z., Wang, M., Wang, N. Y., Wang, R. G., Wang, T., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Webber, D. M., Wei, Y. D., Wen, L. J., Wenman, D. L., Whisnant, K., White, C. G., Whitehead, L., Whitten Jr., C. A., Wilhelmi, J., Wise, T., Wong, H. C., Wong, H. L. H., Wong, J., Worcester, E. T., Wu, F. F., Wu, Q., Xia, D. M., Xiang, S. T., Xiao, Q., Xing, Z. Z., Xu, G., Xu, J., Xu, J. L., Xu, W., Xu, Y., Xue, T., Yang, C. G., Yang, L., Ye, M., Yeh, M., Yeh, Y. S., Yip, K., Young, B. L., Yu, Z. Y., Zhan, L., Zhang, C., Zhang, F. H., Zhang, J. W., Zhang, Q. M., Zhang, K., Zhang, Q. X., Zhang, S. H., Zhang, Y. C., Zhang, Y. H., Zhang, Y. X., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., Zhao, J., Zhao, Q. W., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, Z. Y., Zhuang, H. L., and Zou, J. H.
Subjects: High Energy Physics - Experiment
Abstract: The Daya Bay Reactor Neutrino Experiment has measured a non-zero value for the neutrino mixing angle $\theta_{13}$ with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 GW$_{\rm th}$ reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With a 43,000 ton-GW_{\rm th}-day livetime exposure in 55 days, 10416 (80376) electron antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is $R=0.940\pm 0.011({\rm stat}) \pm 0.004({\rm syst})$. A rate-only analysis finds $\sin^22\theta_{13}=0.092\pm 0.016({\rm stat})\pm0.005({\rm syst})$ in a three-neutrino framework., Comment: 5 figures. Version to appear in Phys. Rev. Lett
Published: 2012
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50. A side-by-side comparison of Daya Bay antineutrino detectors

Author: Daya Bay Collaboration, An, F. P., An, Q., Bai, J. Z., Balantekin, A. B., Band, H. R., Beriguete, W., Bishai, M., Blyth, S., Brown, R. L., Cao, G. F., Cao, J., Carr, R., Chang, J. F., Chang, Y., Chasman, C., Chen, H. S., Chen, S. J., Chen, S. M., Chen, X. C., Chen, X. H., Chen, X. S., Chen, Y., Cherwinka, J. J., Chu, M. C., Cummings, J. P., Deng, Z. Y., Ding, Y. Y., Diwan, M. V., Draeger, E., Du, X. F., Dwyer, D., Edwards, W. R., Ely, S. R., Fang, S. D., Fu, J. Y., Fu, Z. W., Ge, L. Q., Gill, R. L., Gonchar, M., Gong, G. H., Gong, H., Gornushkin, Y. A., Greenler, L. S., Gu, W. Q., Guan, M. Y., Guo, X. H., Hackenburg, R. W., Hahn, R. L., Hans, S., Hao, H. F., He, M., He, Q., He, W. S., Heeger, K. M., Heng, Y. K., Hinrichs, P., Ho, T. H., Hor, Y. K., Hsiung, Y. B., Hu, B. Z., Hu, T., Huang, H. X., Huang, H. Z., Huang, P. W., Huang, X., Huang, X. T., Huber, P., Jaffe, D. E., Jetter, S., Ji, X. L., Ji, X. P., Jiang, H. J., Jiang, W. Q., Jiao, J. B., Johnson, R. A., Kang, L., Kettell, S. H., Kramer, M., Kwan, K. K., Kwok, M. W., Kwok, T., Lai, C. Y., Lai, W. C., Lai, W. H., Lau, K., Lebanowski, L., Lee, M. K. P., Leitner, R., Leung, J. K. C., Leung, K. Y., Lewis, C. A., Li, F., Li, G. S., Li, J., Li, Q. J., Li, S. F., Li, W. D., Li, X. B., Li, X. N., Li, X. Q., Li, Y., Li, Z. B., Liang, H., Lin, C. J., Lin, G. L., Lin, S. K., Lin, S. X., Lin, Y. C., Ling, J. J., Link, J. M., Littenberg, L., Littlejohn, B. R., Liu, B. J., Liu, D. W., Liu, J. C., Liu, J. L., Liu, S., Liu, X., Liu, Y. B., Lu, C., Lu, H. Q., Luk, A., Luk, K. B., Luo, X. L., Ma, L. H., Ma, Q. M., Ma, X. Y., Ma, Y. Q., Mayes, B., McDonald, K. T., McFarlane, M. C., McKeown, R. D., Meng, Y., Mohapatra, D., Nakajima, Y., Napolitano, J., Naumov, D., Nemchenok, I., Newsom, C., Ngai, H. Y., Ngai, W. K., Nie, Y. B., Ning, Z., Ochoa-Ricoux, J. P., Olshevski, A., Pagac, A., Patton, S., Pec, V., Peng, J. C., Piilonen, L. E., Pinsky, L., Pun, C. S. J., Qi, F. Z., Qi, M., Qian, X., Rosero, R., Roskovec, B., Ruan, X. C., Seilhan, B., Shao, B. B., Shih, K., Steiner, H., Stoler, P., Sun, G. X., Sun, J. L., Tam, Y. H., Tanaka, H. K., Tang, X., Torun, Y., Trentalange, S., Tsai, O., Tsang, K. V., Tsang, R. H. M., Tull, C., Viren, B., Vorobel, V., Wang, C. H., Wang, L. S., Wang, L. Y., Wang, M., Wang, N. Y., Wang, R. G., Wang, W., Wang, X., Wang, Y. F., Wang, Z., Wang, Z. M., Webber, D. M., Wei, Y. D., Wen, L. J., Wenman, D. L., Whisnant, K., White, C. G., Whitehead, L., Wilhelmi, J., Wise, T., Wong, H. L. H., Wong, J., Wu, F. F., Wu, Q., Xi, J. B., Xia, D. M., Xiao, Q., Xing, Z. Z., Xu, G., Xu, J., Xu, J. L., Xu, Y., Xue, T., Yang, C. G., Yang, L., Ye, M., Yeh, M., Yeh, Y. S., Young, B. L., Yu, Z. Y., Zhan, L., Zhang, C., Zhang, F. H., Zhang, J. W., Zhang, Q. M., Zhang, S. H., Zhang, Y. C., Zhang, Y. H., Zhang, Y. X., Zhang, Z. J., Zhang, Z. P., Zhang, Z. Y., Zhao, H., Zhao, J., Zhao, Q. W., Zhao, Y. B., Zheng, L., Zhong, W. L., Zhou, L., Zhou, Y. Z., Zhou, Z. Y., Zhuang, H. L., and Zou, J. H.
Subjects: Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract: The Daya Bay Reactor Neutrino Experiment is designed to determine precisely the neutrino mixing angle $\theta_{13}$ with a sensitivity better than 0.01 in the parameter sin$^22\theta_{13}$ at the 90% confidence level. To achieve this goal, the collaboration will build eight functionally identical antineutrino detectors. The first two detectors have been constructed, installed and commissioned in Experimental Hall 1, with steady data-taking beginning September 23, 2011. A comparison of the data collected over the subsequent three months indicates that the detectors are functionally identical, and that detector-related systematic uncertainties exceed requirements., Comment: 24 pages, 36 figures
Published: 2012
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