Author: "Qiu, Y.-L." / Database: OAIster - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Qiu, Y.-L."' showing total 53 results

Start Over Author "Qiu, Y.-L." Database OAIster

53 results on '"Qiu, Y.-L."'

1. Changing-look NLS1 galaxies, their detection with SVOM, and the case of NGC 1566

Author: Xu, D. W., Komossa, S., Grupe, D., Wang, J., Xin, L. P., Han, X. H., Wei, J. Y., Bai, J. Y., Bon, E., Cangemi, F., Cordier, B., Dennefeld, M., Gallo, L. C., Kollatschny, W., Kong, De-Feng, Ochmann, M. W., Qiu, Y. L., Schartel, N., Xu, D. W., Komossa, S., Grupe, D., Wang, J., Xin, L. P., Han, X. H., Wei, J. Y., Bai, J. Y., Bon, E., Cangemi, F., Cordier, B., Dennefeld, M., Gallo, L. C., Kollatschny, W., Kong, De-Feng, Ochmann, M. W., Qiu, Y. L., and Schartel, N.
Abstract: We discuss applications of the study of the new and barely explored class of changing-look (CL) narrow-line Seyfert 1 (NLS1) galaxies and comment on their detection with the space mission SVOM (Space Variable Objects Monitor). We highlight the case of NGC 1566, which is outstanding in many respects, for instance as one of the nearest known CL AGN undergoing exceptional outbursts. Its NLS1 nature is discussed, and we take it as a nearby prototype for systems that could be discovered and studied in the near future, including with SVOM. Finally, we briefly examine the broader implications and applications of CL events in NLS1 galaxies and show that such systems, once discovered in larger numbers, will greatly advance our understanding of the physics of the environment of rapidly growing supermassive black holes. This White Paper is part of a sequence of publications which explore aspects of our understanding of (CL) NLS1 galaxy physics with future missions., Comment: 14 pages, 4 figures. Accepted for publication in the Universe Special Issue "A Multimessenger View of Supermassive Black Holes and the Quasar Main Sequence"
Published: 2024

2. The Lobster Eye Imager for Astronomy Onboard the SATech-01 Satellite

Author: Ling, Z. X., Sun, X. J., Zhang, C., Sun, S. L., Jin, G., Zhang, S. N., Zhang, X. F., Chang, J. B., Chen, F. S., Chen, Y. F., Cheng, Z. W., Fu, W., Han, Y. X., Li, H., Li, J. F., Li, Y., Li, Z. D., Liu, P. R., Lv, Y. H., Ma, X. H., Tang, Y. J., Wang, C. B., Xie, R. J., Xue, Y. L., Yan, A. L., Zhang, Q., Bao, C. Y., Cai, H. B., Cheng, H. Q., Cui, C. Z., Dai, Y. F., Fan, D. W., Hu, H. B., Hu, J. W., Huang, M. H., Jia, Z. Q., Jin, C. C., Li, D. Y., Li, J. Q., Liu, H. Y., Liu, M. J., Liu, Y., Pan, H. W., Qiu, Y. L., Sugizaki, M., Sun, H., Wang, W. X., Wang, Y. L., Wu, Q. Y., Xu, X. P., Xu, Y. F., Yang, H. N., Yang, X., Zhang, B., Zhang, M., Zhang, W. D., Zhang, Z., Zhao, D. H., Cong, X. Q., Jiang, B. W., Li, L. H., Qiu, X. B., Sun, J. N., Su, D. T., Wang, J., Wu, C., Xu, Z., Yang, X. M., Zhang, S. K., Zhang, N., Zhu, Y. F., Ban, H. Y., Bi, X. Z., Cai, Z. M., Chen, W., Chen, X., Chen, Y. H., Cui, Y., Duan, X. L., Feng, Z. G, Gao, Y., He, J. W., He, T., Huang, J. J., Li, F., Li, J. S., Li, T. J., Li, T. T., Liu, H. Q., Liu, L., Liu, R., Liu, S., Meng, N., Shi, Q., Sun, A. T., Wang, Y. M., Wang, Y. B., Wu, H. C., Xu, D. X, Yang, Y. Q, Yang, Y., Yu, X. S., Zhang, K. X., Zhang, Y. L., Zhang, Y. H., Zhang, Y. T., Zhou, H., Zhu, X. C., Cheng, J. S., Qin, L., Wang, L., Wang, Q. L., Bai, M., Gao, R. L., Ji, Z., Liu, Y. R., Ma, F. L., Shi, Y. J., Su, J., Tan, Y. Y., Tong, J. Z., Xu, H. T., Xue, C. B., Xue, G. F., Yuan, W., Ling, Z. X., Sun, X. J., Zhang, C., Sun, S. L., Jin, G., Zhang, S. N., Zhang, X. F., Chang, J. B., Chen, F. S., Chen, Y. F., Cheng, Z. W., Fu, W., Han, Y. X., Li, H., Li, J. F., Li, Y., Li, Z. D., Liu, P. R., Lv, Y. H., Ma, X. H., Tang, Y. J., Wang, C. B., Xie, R. J., Xue, Y. L., Yan, A. L., Zhang, Q., Bao, C. Y., Cai, H. B., Cheng, H. Q., Cui, C. Z., Dai, Y. F., Fan, D. W., Hu, H. B., Hu, J. W., Huang, M. H., Jia, Z. Q., Jin, C. C., Li, D. Y., Li, J. Q., Liu, H. Y., Liu, M. J., Liu, Y., Pan, H. W., Qiu, Y. L., Sugizaki, M., Sun, H., Wang, W. X., Wang, Y. L., Wu, Q. Y., Xu, X. P., Xu, Y. F., Yang, H. N., Yang, X., Zhang, B., Zhang, M., Zhang, W. D., Zhang, Z., Zhao, D. H., Cong, X. Q., Jiang, B. W., Li, L. H., Qiu, X. B., Sun, J. N., Su, D. T., Wang, J., Wu, C., Xu, Z., Yang, X. M., Zhang, S. K., Zhang, N., Zhu, Y. F., Ban, H. Y., Bi, X. Z., Cai, Z. M., Chen, W., Chen, X., Chen, Y. H., Cui, Y., Duan, X. L., Feng, Z. G, Gao, Y., He, J. W., He, T., Huang, J. J., Li, F., Li, J. S., Li, T. J., Li, T. T., Liu, H. Q., Liu, L., Liu, R., Liu, S., Meng, N., Shi, Q., Sun, A. T., Wang, Y. M., Wang, Y. B., Wu, H. C., Xu, D. X, Yang, Y. Q, Yang, Y., Yu, X. S., Zhang, K. X., Zhang, Y. L., Zhang, Y. H., Zhang, Y. T., Zhou, H., Zhu, X. C., Cheng, J. S., Qin, L., Wang, L., Wang, Q. L., Bai, M., Gao, R. L., Ji, Z., Liu, Y. R., Ma, F. L., Shi, Y. J., Su, J., Tan, Y. Y., Tong, J. Z., Xu, H. T., Xue, C. B., Xue, G. F., and Yuan, W.
Abstract: The Lobster Eye Imager for Astronomy (LEIA), a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe (EP) mission, was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on 27 July 2022. In this paper, we introduce the design and on-ground test results of the LEIA instrument. Using state-of-the-art Micro-Pore Optics (MPO), a wide field-of-view (FoV) of 346 square degrees (18.6 degrees * 18.6 degrees) of the X-ray imager is realized. An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons, and four large-format complementary metal-oxide semiconductor (CMOS) sensors, each of 6 cm * 6 cm, are used as the focal plane detectors. The instrument has an angular resolution of 4 - 8 arcmin (in FWHM) for the central focal spot of the point spread function, and an effective area of 2 - 3 cm2 at 1 keV in essentially all the directions within the field of view. The detection passband is 0.5 - 4 keV in the soft X-rays and the sensitivity is 2 - 3 * 10-11 erg s-1 cm-2 (about 1 mini-Crab) at 1,000 second observation. The total weight of LEIA is 56 kg and the power is 85 W. The satellite, with a design lifetime of 2 years, operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes. LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation, and by optimizing the working setups of the instrumental parameters. In addition, LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band, albeit limited useful observing time available., Comment: Accepted by RAA
Published: 2023
Full Text: View/download PDF

3. The Lobster Eye Imager for Astronomy Onboard the SATech-01 Satellite

Author: Ling, Z. X., Sun, X. J., Zhang, C., Sun, S. L., Jin, G., Zhang, S. N., Zhang, X. F., Chang, J. B., Chen, F. S., Chen, Y. F., Cheng, Z. W., Fu, W., Han, Y. X., Li, H., Li, J. F., Li, Y., Li, Z. D., Liu, P. R., Lv, Y. H., Ma, X. H., Tang, Y. J., Wang, C. B., Xie, R. J., Xue, Y. L., Yan, A. L., Zhang, Q., Bao, C. Y., Cai, H. B., Cheng, H. Q., Cui, C. Z., Dai, Y. F., Fan, D. W., Hu, H. B., Hu, J. W., Huang, M. H., Jia, Z. Q., Jin, C. C., Li, D. Y., Li, J. Q., Liu, H. Y., Liu, M. J., Liu, Y., Pan, H. W., Qiu, Y. L., Sugizaki, M., Sun, H., Wang, W. X., Wang, Y. L., Wu, Q. Y., Xu, X. P., Xu, Y. F., Yang, H. N., Yang, X., Zhang, B., Zhang, M., Zhang, W. D., Zhang, Z., Zhao, D. H., Cong, X. Q., Jiang, B. W., Li, L. H., Qiu, X. B., Sun, J. N., Su, D. T., Wang, J., Wu, C., Xu, Z., Yang, X. M., Zhang, S. K., Zhang, N., Zhu, Y. F., Ban, H. Y., Bi, X. Z., Cai, Z. M., Chen, W., Chen, X., Chen, Y. H., Cui, Y., Duan, X. L., Feng, Z. G, Gao, Y., He, J. W., He, T., Huang, J. J., Li, F., Li, J. S., Li, T. J., Li, T. T., Liu, H. Q., Liu, L., Liu, R., Liu, S., Meng, N., Shi, Q., Sun, A. T., Wang, Y. M., Wang, Y. B., Wu, H. C., Xu, D. X, Yang, Y. Q, Yang, Y., Yu, X. S., Zhang, K. X., Zhang, Y. L., Zhang, Y. H., Zhang, Y. T., Zhou, H., Zhu, X. C., Cheng, J. S., Qin, L., Wang, L., Wang, Q. L., Bai, M., Gao, R. L., Ji, Z., Liu, Y. R., Ma, F. L., Shi, Y. J., Su, J., Tan, Y. Y., Tong, J. Z., Xu, H. T., Xue, C. B., Xue, G. F., Yuan, W., Ling, Z. X., Sun, X. J., Zhang, C., Sun, S. L., Jin, G., Zhang, S. N., Zhang, X. F., Chang, J. B., Chen, F. S., Chen, Y. F., Cheng, Z. W., Fu, W., Han, Y. X., Li, H., Li, J. F., Li, Y., Li, Z. D., Liu, P. R., Lv, Y. H., Ma, X. H., Tang, Y. J., Wang, C. B., Xie, R. J., Xue, Y. L., Yan, A. L., Zhang, Q., Bao, C. Y., Cai, H. B., Cheng, H. Q., Cui, C. Z., Dai, Y. F., Fan, D. W., Hu, H. B., Hu, J. W., Huang, M. H., Jia, Z. Q., Jin, C. C., Li, D. Y., Li, J. Q., Liu, H. Y., Liu, M. J., Liu, Y., Pan, H. W., Qiu, Y. L., Sugizaki, M., Sun, H., Wang, W. X., Wang, Y. L., Wu, Q. Y., Xu, X. P., Xu, Y. F., Yang, H. N., Yang, X., Zhang, B., Zhang, M., Zhang, W. D., Zhang, Z., Zhao, D. H., Cong, X. Q., Jiang, B. W., Li, L. H., Qiu, X. B., Sun, J. N., Su, D. T., Wang, J., Wu, C., Xu, Z., Yang, X. M., Zhang, S. K., Zhang, N., Zhu, Y. F., Ban, H. Y., Bi, X. Z., Cai, Z. M., Chen, W., Chen, X., Chen, Y. H., Cui, Y., Duan, X. L., Feng, Z. G, Gao, Y., He, J. W., He, T., Huang, J. J., Li, F., Li, J. S., Li, T. J., Li, T. T., Liu, H. Q., Liu, L., Liu, R., Liu, S., Meng, N., Shi, Q., Sun, A. T., Wang, Y. M., Wang, Y. B., Wu, H. C., Xu, D. X, Yang, Y. Q, Yang, Y., Yu, X. S., Zhang, K. X., Zhang, Y. L., Zhang, Y. H., Zhang, Y. T., Zhou, H., Zhu, X. C., Cheng, J. S., Qin, L., Wang, L., Wang, Q. L., Bai, M., Gao, R. L., Ji, Z., Liu, Y. R., Ma, F. L., Shi, Y. J., Su, J., Tan, Y. Y., Tong, J. Z., Xu, H. T., Xue, C. B., Xue, G. F., and Yuan, W.
Abstract: The Lobster Eye Imager for Astronomy (LEIA), a pathfinder of the Wide-field X-ray Telescope of the Einstein Probe (EP) mission, was successfully launched onboard the SATech-01 satellite of the Chinese Academy of Sciences on 27 July 2022. In this paper, we introduce the design and on-ground test results of the LEIA instrument. Using state-of-the-art Micro-Pore Optics (MPO), a wide field-of-view (FoV) of 346 square degrees (18.6 degrees * 18.6 degrees) of the X-ray imager is realized. An optical assembly composed of 36 MPO chips is used to focus incident X-ray photons, and four large-format complementary metal-oxide semiconductor (CMOS) sensors, each of 6 cm * 6 cm, are used as the focal plane detectors. The instrument has an angular resolution of 4 - 8 arcmin (in FWHM) for the central focal spot of the point spread function, and an effective area of 2 - 3 cm2 at 1 keV in essentially all the directions within the field of view. The detection passband is 0.5 - 4 keV in the soft X-rays and the sensitivity is 2 - 3 * 10-11 erg s-1 cm-2 (about 1 mini-Crab) at 1,000 second observation. The total weight of LEIA is 56 kg and the power is 85 W. The satellite, with a design lifetime of 2 years, operates in a Sun-synchronous orbit of 500 km with an orbital period of 95 minutes. LEIA is paving the way for future missions by verifying in flight the technologies of both novel focusing imaging optics and CMOS sensors for X-ray observation, and by optimizing the working setups of the instrumental parameters. In addition, LEIA is able to carry out scientific observations to find new transients and to monitor known sources in the soft X-ray band, albeit limited useful observing time available., Comment: Accepted by RAA
Published: 2023
Full Text: View/download PDF

4. Constrains on optical emission of FAST-detected FRB 20181130B with GWAC synchronized observations

Author: Xin, L. P., Li, H. L., Wang, J., Han, X. H., Qiu, Y. L., Cai, H. B., Niu, C. H., Lu, X. M., Liang, E. W., Dai, Z. G., Wang, X. G., Wang, X. Y., Huang, L., Wu, C., Li, G. W., Feng, Q. C., Deng, J. S., Sun, S. S., Yang, Y. G., Wei, J. Y., Xin, L. P., Li, H. L., Wang, J., Han, X. H., Qiu, Y. L., Cai, H. B., Niu, C. H., Lu, X. M., Liang, E. W., Dai, Z. G., Wang, X. G., Wang, X. Y., Huang, L., Wu, C., Li, G. W., Feng, Q. C., Deng, J. S., Sun, S. S., Yang, Y. G., and Wei, J. Y.
Abstract: Multi-wavelength simultaneous observations are essential to the constraints on the origin of fast radio bursts (FRBs). However, it is a significant observational challenge due to the nature of FRBs as transients with a radio millisecond duration, which occur randomly in the sky regardless of time and position. Here, we report the search for short-time fast optical bursts in the GWAC archived data associated with FRB 20181130B, which were detected by the Five Hundred Meter Spherical Radio Telescope (FAST) and recently reported. No new credible sources were detected in all single GWAC images with an exposure time of 10 s, including image with coverage of the expected arrival time in optical wavelength by taking the high dispersion measurements into account. Our results provide a limiting magnitude of 15.43$\pm0.04$ mag in R band, corresponding to a flux density of 1.66 Jy or 8.35 mag in AB system by assuming that the duration of the optical band is similar to that of the radio band of about 10 ms. This limiting magnitude makes the spectral index of $\alpha<0.367$ from optical to radio wavelength. The possible existence of longer duration optical emission was also investigated with an upper limits of 0.33 Jy (10.10 mag), 1.74 mJy (15.80 mag) and 0.16 mJy (18.39 mag) for the duration of 50 ms, 10 s and 6060 s, respectively. This undetected scenario could be partially attributed to the shallow detection capability, as well as the high inferred distance of FRB 20181130B and the low fluence in radio wavelength. The future detectability of optical flashes associated with nearby and bright FRBs are also discussed in this paper., Comment: Accepted by ApJ
Published: 2021
Full Text: View/download PDF

5. Constrains on optical emission of FAST-detected FRB 20181130B with GWAC synchronized observations

Author: Xin, L. P., Li, H. L., Wang, J., Han, X. H., Qiu, Y. L., Cai, H. B., Niu, C. H., Lu, X. M., Liang, E. W., Dai, Z. G., Wang, X. G., Wang, X. Y., Huang, L., Wu, C., Li, G. W., Feng, Q. C., Deng, J. S., Sun, S. S., Yang, Y. G., Wei, J. Y., Xin, L. P., Li, H. L., Wang, J., Han, X. H., Qiu, Y. L., Cai, H. B., Niu, C. H., Lu, X. M., Liang, E. W., Dai, Z. G., Wang, X. G., Wang, X. Y., Huang, L., Wu, C., Li, G. W., Feng, Q. C., Deng, J. S., Sun, S. S., Yang, Y. G., and Wei, J. Y.
Abstract: Multi-wavelength simultaneous observations are essential to the constraints on the origin of fast radio bursts (FRBs). However, it is a significant observational challenge due to the nature of FRBs as transients with a radio millisecond duration, which occur randomly in the sky regardless of time and position. Here, we report the search for short-time fast optical bursts in the GWAC archived data associated with FRB 20181130B, which were detected by the Five Hundred Meter Spherical Radio Telescope (FAST) and recently reported. No new credible sources were detected in all single GWAC images with an exposure time of 10 s, including image with coverage of the expected arrival time in optical wavelength by taking the high dispersion measurements into account. Our results provide a limiting magnitude of 15.43$\pm0.04$ mag in R band, corresponding to a flux density of 1.66 Jy or 8.35 mag in AB system by assuming that the duration of the optical band is similar to that of the radio band of about 10 ms. This limiting magnitude makes the spectral index of $\alpha<0.367$ from optical to radio wavelength. The possible existence of longer duration optical emission was also investigated with an upper limits of 0.33 Jy (10.10 mag), 1.74 mJy (15.80 mag) and 0.16 mJy (18.39 mag) for the duration of 50 ms, 10 s and 6060 s, respectively. This undetected scenario could be partially attributed to the shallow detection capability, as well as the high inferred distance of FRB 20181130B and the low fluence in radio wavelength. The future detectability of optical flashes associated with nearby and bright FRBs are also discussed in this paper., Comment: Accepted by ApJ
Published: 2021
Full Text: View/download PDF

6. A Pilot Study of Catching High-$z$ GRBs and Exploring Circumburst Environment in the Forthcoming SVOM Era

Author: Wang, J., Qiu, Y. L., Wei, J. Y., Wang, J., Qiu, Y. L., and Wei, J. Y.
Abstract: Rapid spectroscopy of GRB afterglows is an important and hard task. Based on the archival XS-GRB spectral database, we here perform a pilot study on the afterglow's spectroscopy in the forthcoming \it SVOM \rm era in two aspects. At first, our simulation indicates that the color acquired from the \it SVOM\rm/VT blue and red channels is effective in discriminating between low-$z$ ($z\lesssim3$) and distant GRB candidates until $z\sim6$. Secondly, by doubling the sample size, we find that the previously proposed global photoionization response of the circumburst gas to the prompt emission (i.e., the CIV/CII-$L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$ relationship) is roughly confirmed, although the confirmation is dissatisfactory at the large $L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$ end. We believe that this issue can be further addressed in the \it SVOM \rm era by larger spectroscopy sample, thanks to its capability of rapid identification of optical candidates of afterglow and its anti-solar pointing strategy., Comment: 8 pages, 1 table and 3 figures, to be published in RAA
Published: 2020
Full Text: View/download PDF

7. A $\Delta R\sim 9.5$ mag Super Flare of An Ultracool Star Detected by $\text{SVOM/GWAC}$ System

Author: Xin, L. P., Li, H. L., Wang, J., Han, X. H., Xu, Y., Meng, X. M., Cai, H. B., Huang, L., Lu, X. M., Qiu, Y. L., Wang, X. G., Liang, E. W., Dai, Z. G., Wang, X. Y., Wu, C., Zhang, J. B., Li, G. W., Turpin, D., Feng, Q. C., Deng, J. S., Sun, S. S., Zheng, T. C., Yang, Y. G., Wei, J. Y., Xin, L. P., Li, H. L., Wang, J., Han, X. H., Xu, Y., Meng, X. M., Cai, H. B., Huang, L., Lu, X. M., Qiu, Y. L., Wang, X. G., Liang, E. W., Dai, Z. G., Wang, X. Y., Wu, C., Zhang, J. B., Li, G. W., Turpin, D., Feng, Q. C., Deng, J. S., Sun, S. S., Zheng, T. C., Yang, Y. G., and Wei, J. Y.
Abstract: In this paper, we report the detection and follow-ups of a super stellar flare GWAC\,181229A with an amplitude of $\Delta R\sim$9.5 mag on a M9 type star by $\text{SVOM/GWAC}$ and the dedicated follow-up telescopes. The estimated bolometric energy $E_{bol}$ is $(5.56-9.25)\times10^{34}$ ergs, which places the event to be one of the most powerful flares on ultracool stars. The magnetic strength is inferred to be (3.6-4.7) kG. Thanks to the sampling with a cadence of 15 seconds, a new component near the peak time with a very steep decay is detected in the $R$-band light curve, followed by the two-component flare template given by Davenport et al. (2014). An effective temperature of $5340\pm40$ K is measured by a blackbody shape fitting to the spectrum at the shallower phase during the flare. The filling factors of the flare are estimated to be $\sim$30\% and 19\% at the peak time and at 54 min after the first detection. The detection of the particular event with large amplitude, huge-emitted energy and a new component demonstrates that a high cadence sky monitoring cooperating with fast follow-up observations is very essential for understanding the violent magnetic activity., Comment: 14 pages, 12 figures, 4 tables, accepted by ApJ
Published: 2020
Full Text: View/download PDF

8. A Pilot Study of Catching High-$z$ GRBs and Exploring Circumburst Environment in the Forthcoming SVOM Era

Author: Wang, J., Qiu, Y. L., Wei, J. Y., Wang, J., Qiu, Y. L., and Wei, J. Y.
Abstract: Rapid spectroscopy of GRB afterglows is an important and hard task. Based on the archival XS-GRB spectral database, we here perform a pilot study on the afterglow's spectroscopy in the forthcoming \it SVOM \rm era in two aspects. At first, our simulation indicates that the color acquired from the \it SVOM\rm/VT blue and red channels is effective in discriminating between low-$z$ ($z\lesssim3$) and distant GRB candidates until $z\sim6$. Secondly, by doubling the sample size, we find that the previously proposed global photoionization response of the circumburst gas to the prompt emission (i.e., the CIV/CII-$L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$ relationship) is roughly confirmed, although the confirmation is dissatisfactory at the large $L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$ end. We believe that this issue can be further addressed in the \it SVOM \rm era by larger spectroscopy sample, thanks to its capability of rapid identification of optical candidates of afterglow and its anti-solar pointing strategy., Comment: 8 pages, 1 table and 3 figures, to be published in RAA
Published: 2020
Full Text: View/download PDF

9. Photometric and spectroscopic Studies of Superoutbursts of Three Dwarf Novae Independently Identified by The SVOM/GWAC System in 2018

Author: Wang, J., Li, H. L., Xin, L. P., Han, X. H., Meng, X. M., Brink, T. G., Cai, H. B., Dai, Z. G., Filippenko, A. V., Hsia, C. -H., Huang, L., Jia, L., Li, G. W., Li, Y. B., Liang, E. W., Lu, X. M., Mao, J., Qiu, P., Qiu, Y. L., Ren, J. J., Turpin, D., Wang, H. J., Wang, X. G., Wang, X. Y., Wu, C., Xu, Y., Yan, J. Z., Zhang, J. B., Zheng, W., Wei, J. Y., Wang, J., Li, H. L., Xin, L. P., Han, X. H., Meng, X. M., Brink, T. G., Cai, H. B., Dai, Z. G., Filippenko, A. V., Hsia, C. -H., Huang, L., Jia, L., Li, G. W., Li, Y. B., Liang, E. W., Lu, X. M., Mao, J., Qiu, P., Qiu, Y. L., Ren, J. J., Turpin, D., Wang, H. J., Wang, X. G., Wang, X. Y., Wu, C., Xu, Y., Yan, J. Z., Zhang, J. B., Zheng, W., and Wei, J. Y.
Abstract: We report our photometric and spectroscopic follow-up observations of the superoutbursts of three dwarf novae (GWAC\,180415A, GWAC\,181017A and GWAC\,181211A) identified independently by the Ground Wide-angle Cameras system, one of the ground-based instruments of the China-France SVOM mission. Based on a combination of our photometry and that taken from the AAVSO, our period analysis of the superhumps enables us to determine the mass ratios to be 0.0967-0.1163, 0.1879-0.1883 and 0.0981-0.1173 for GWAC\,180415A, GWAC\,181017A and GWAC\,181211A, respectively. GWAC\,180415A can be firmly identified as a WZ sge-type dwarf novae due to its long duration ($\sim2$ weeks) multiple rebrightenings with amplitudes of 3-4 magnitudes, the early superhump associated with a double-wave modulation and the low mass ratio. The inferred low mass ratio and location in the $\varepsilon-P_{\mathrm{orb}}$ diagram suggest that GWAC\,181211A is a WZ sge-type dwarf novae candidate. The measured Balmer decrements suggest the Balmer line emission is produced from an optical thick region in GWAC\,180415A and GWAC\,181017A, and from an optical thin region in GWAC\,181211A., Comment: 15 pages, 13 figures and 5 tables, to appear in AJ
Published: 2019

10. The mini-GWAC optical follow-up of the gravitational wave alerts: results from the O2 campaign and prospects for the upcoming O3 run

Author: Turpin, D., Wu, C., Han, X. H., Xin, L. P., Antier, S., Leroy, N., Cao, L., Cai, H. B., Cordier, B., Deng, J. S., Dong, W. L., Feng, Q. C., Huang, L., Jia, L., Klotz, A., Lachaud, C., Li, H. L., Liang, E. W., Liu, S. F., Lu, X. M., Meng, X. M., Qiu, Y. L., Wang, H. J., Wang, J., Wang, S., Wang, X. G., Wei, J. Y., Wu, B. B., Xiao, Y. J., Xu, D. W., Xu, Y., Yang, Y. G., Zhang, P. P., Zhang, R. S., Zhang, S. N., Zheng, Y. T., Zou, S. C., Turpin, D., Wu, C., Han, X. H., Xin, L. P., Antier, S., Leroy, N., Cao, L., Cai, H. B., Cordier, B., Deng, J. S., Dong, W. L., Feng, Q. C., Huang, L., Jia, L., Klotz, A., Lachaud, C., Li, H. L., Liang, E. W., Liu, S. F., Lu, X. M., Meng, X. M., Qiu, Y. L., Wang, H. J., Wang, J., Wang, S., Wang, X. G., Wei, J. Y., Wu, B. B., Xiao, Y. J., Xu, D. W., Xu, Y., Yang, Y. G., Zhang, P. P., Zhang, R. S., Zhang, S. N., Zheng, Y. T., and Zou, S. C.
Abstract: The second observational campaign of gravitational waves organized by the LIGO/Virgo Collaborations has led to several breakthroughs such as the detection of gravitational wave signals from merger systems involving black holes or neutrons stars. During O2,14 gravitational wave alerts were sent to the astronomical community with sky regions covering mostly over hundreds of square degrees. Among them, 6 have been finally confirmed as real astrophysical events. Since 2013, a new set of ground-based robotic telescopes called GWAC and its pathfinder mini-GWAC have been developed to contribute to the various challenges of themulti-messenger and time domain astronomy. The GWAC system is built up in the framework of the ground-segment system of the SVOM mission that will be devoted to the study of the multi-wavelength transient sky in the next decade. During O2, only the mini-GWAC telescopenetwork was fully operational. Due to the wide field of view and fast automatic follow-up capabilities of the mini-GWAC telescopes, they were well adapted to efficiently cover the sky localization areas of the gravitational wave event candidates. In this paper, we present the mini-GWAC pipeline we have set up to respond to the GW alerts and we report our optical follow-up observations of 8 GW alerts detected during the O2 run. Our observations provided the largest coverage of the GW localization areas in a short latency made by any optical facility. We found tens of optical transient candidates in our images, but none of those could be securely associated with any confirmed black hole-black hole merger event. Based on this first experience and the near future technical improvements of our network system, we will be more competitive to detect the optical counterparts from some gravitational wave events that will be detected during the upcoming O3 run, especially those emerging from binary neutron star mergers., Comment: 17 pages, 10 figures, 11 tables
Published: 2019
Full Text: View/download PDF

11. The mini-GWAC optical follow-up of the gravitational wave alerts: results from the O2 campaign and prospects for the upcoming O3 run

Author: Turpin, D., Wu, C., Han, X. H., Xin, L. P., Antier, S., Leroy, N., Cao, L., Cai, H. B., Cordier, B., Deng, J. S., Dong, W. L., Feng, Q. C., Huang, L., Jia, L., Klotz, A., Lachaud, C., Li, H. L., Liang, E. W., Liu, S. F., Lu, X. M., Meng, X. M., Qiu, Y. L., Wang, H. J., Wang, J., Wang, S., Wang, X. G., Wei, J. Y., Wu, B. B., Xiao, Y. J., Xu, D. W., Xu, Y., Yang, Y. G., Zhang, P. P., Zhang, R. S., Zhang, S. N., Zheng, Y. T., Zou, S. C., Turpin, D., Wu, C., Han, X. H., Xin, L. P., Antier, S., Leroy, N., Cao, L., Cai, H. B., Cordier, B., Deng, J. S., Dong, W. L., Feng, Q. C., Huang, L., Jia, L., Klotz, A., Lachaud, C., Li, H. L., Liang, E. W., Liu, S. F., Lu, X. M., Meng, X. M., Qiu, Y. L., Wang, H. J., Wang, J., Wang, S., Wang, X. G., Wei, J. Y., Wu, B. B., Xiao, Y. J., Xu, D. W., Xu, Y., Yang, Y. G., Zhang, P. P., Zhang, R. S., Zhang, S. N., Zheng, Y. T., and Zou, S. C.
Abstract: The second observational campaign of gravitational waves organized by the LIGO/Virgo Collaborations has led to several breakthroughs such as the detection of gravitational wave signals from merger systems involving black holes or neutrons stars. During O2,14 gravitational wave alerts were sent to the astronomical community with sky regions covering mostly over hundreds of square degrees. Among them, 6 have been finally confirmed as real astrophysical events. Since 2013, a new set of ground-based robotic telescopes called GWAC and its pathfinder mini-GWAC have been developed to contribute to the various challenges of themulti-messenger and time domain astronomy. The GWAC system is built up in the framework of the ground-segment system of the SVOM mission that will be devoted to the study of the multi-wavelength transient sky in the next decade. During O2, only the mini-GWAC telescopenetwork was fully operational. Due to the wide field of view and fast automatic follow-up capabilities of the mini-GWAC telescopes, they were well adapted to efficiently cover the sky localization areas of the gravitational wave event candidates. In this paper, we present the mini-GWAC pipeline we have set up to respond to the GW alerts and we report our optical follow-up observations of 8 GW alerts detected during the O2 run. Our observations provided the largest coverage of the GW localization areas in a short latency made by any optical facility. We found tens of optical transient candidates in our images, but none of those could be securely associated with any confirmed black hole-black hole merger event. Based on this first experience and the near future technical improvements of our network system, we will be more competitive to detect the optical counterparts from some gravitational wave events that will be detected during the upcoming O3 run, especially those emerging from binary neutron star mergers., Comment: 17 pages, 10 figures, 11 tables
Published: 2019
Full Text: View/download PDF

12. Photometric and spectroscopic Studies of Superoutbursts of Three Dwarf Novae Independently Identified by The SVOM/GWAC System in 2018

Author: Wang, J., Li, H. L., Xin, L. P., Han, X. H., Meng, X. M., Brink, T. G., Cai, H. B., Dai, Z. G., Filippenko, A. V., Hsia, C. -H., Huang, L., Jia, L., Li, G. W., Li, Y. B., Liang, E. W., Lu, X. M., Mao, J., Qiu, P., Qiu, Y. L., Ren, J. J., Turpin, D., Wang, H. J., Wang, X. G., Wang, X. Y., Wu, C., Xu, Y., Yan, J. Z., Zhang, J. B., Zheng, W., Wei, J. Y., Wang, J., Li, H. L., Xin, L. P., Han, X. H., Meng, X. M., Brink, T. G., Cai, H. B., Dai, Z. G., Filippenko, A. V., Hsia, C. -H., Huang, L., Jia, L., Li, G. W., Li, Y. B., Liang, E. W., Lu, X. M., Mao, J., Qiu, P., Qiu, Y. L., Ren, J. J., Turpin, D., Wang, H. J., Wang, X. G., Wang, X. Y., Wu, C., Xu, Y., Yan, J. Z., Zhang, J. B., Zheng, W., and Wei, J. Y.
Abstract: We report our photometric and spectroscopic follow-up observations of the superoutbursts of three dwarf novae (GWAC\,180415A, GWAC\,181017A and GWAC\,181211A) identified independently by the Ground Wide-angle Cameras system, one of the ground-based instruments of the China-France SVOM mission. Based on a combination of our photometry and that taken from the AAVSO, our period analysis of the superhumps enables us to determine the mass ratios to be 0.0967-0.1163, 0.1879-0.1883 and 0.0981-0.1173 for GWAC\,180415A, GWAC\,181017A and GWAC\,181211A, respectively. GWAC\,180415A can be firmly identified as a WZ sge-type dwarf novae due to its long duration ($\sim2$ weeks) multiple rebrightenings with amplitudes of 3-4 magnitudes, the early superhump associated with a double-wave modulation and the low mass ratio. The inferred low mass ratio and location in the $\varepsilon-P_{\mathrm{orb}}$ diagram suggest that GWAC\,181211A is a WZ sge-type dwarf novae candidate. The measured Balmer decrements suggest the Balmer line emission is produced from an optical thick region in GWAC\,180415A and GWAC\,181017A, and from an optical thin region in GWAC\,181211A., Comment: 15 pages, 13 figures and 5 tables, to appear in AJ
Published: 2019

13. Broad-lined type Ic supernova iPTF16asu: A challenge to all popular models

Author: Ministry of Science and Technology of the People's Republic of China, National Natural Science Foundation of China, University of California, Berkeley, University of Nevada, Las Vegas, Wang, L. J., Wang, X. F., Cano, Z., Wang, S. Q., Liu, L.D., Dai, Z. G., Deng, J. S., Yu, H., Li, B., Song, L. M., Qiu, Y. L., Wei, J. Y., Ministry of Science and Technology of the People's Republic of China, National Natural Science Foundation of China, University of California, Berkeley, University of Nevada, Las Vegas, Wang, L. J., Wang, X. F., Cano, Z., Wang, S. Q., Liu, L.D., Dai, Z. G., Deng, J. S., Yu, H., Li, B., Song, L. M., Qiu, Y. L., and Wei, J. Y.
Abstract: It is well known that ordinary supernovae (SNe) are powered by 56Ni cascade decay. Broad-lined type Ic SNe (SNe Ic-BL) are a subclass of SNe that are not all exclusively powered by 56Ni decay. It was suggested that some SNe Ic-BL are powered by magnetar spin-down. iPTF16asu is a peculiar broad-lined type Ic supernova discovered by the intermediate Palomar Transient Factory. With a rest-frame rise time of only 4 d, iPTF16asu challenges the existing popular models, for example, the radioactive heating (56Ni-only) and the magnetar +56Ni models. Here we show that this rapid rise could be attributed to interaction between the SN ejecta and a pre-existing circumstellar medium ejected by the progenitor during its final stages of evolution, while the late-time light curve can be better explained by energy input from a rapidly spinning magnetar. This model is a natural extension to the previous magnetar model. The mass-loss rate of the progenitor and ejecta mass are consistent with a progenitor that experienced a common envelope evolution in a binary. An alternative model for the early rapid rise of the light curve is the cooling of a shock propagating into an extended envelope of the progenitor. It is difficult at this stage to tell which model (interaction+magnetar + 56Ni or cooling+magnetar + 56Ni) is better for iPTF16asu. However, it is worth noting that the inferred envelope mass in the cooling+magnetar + 56Ni is very high.© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
Published: 2019

14. Spectroscopy of the Type Ic Supernova SN\,2017iuk Associated with Low-redshift GRB\,171205A

Author: Wang, J., Zhu, Z. P., Xu, D., Xin, L. P., Deng, J. S., Qiu, Y. L., Qiu, P., Wang, H. J., Zhang, J. B., Wei, J. Y., Wang, J., Zhu, Z. P., Xu, D., Xin, L. P., Deng, J. S., Qiu, Y. L., Qiu, P., Wang, H. J., Zhang, J. B., and Wei, J. Y.
Abstract: We here report a spectroscopic monitor for the supernova SN\,2017iuk associated with the long-duration low-luminosity gamma-ray burst GRB\,171205A at a redshift of 0.037, which is up to now the third GRB-SN event away from us. Our spectroscopic observations and spectral analysis allow us to identify SN\,2017iuk as a typical broad-line type Ic SN. A comparison study suggests that the type-IcBL SN\,2017iuk resembles to SN\,2006aj in following aspects: 1) similar spectra at the nearby epochs, 2) comparable evolution of the photospheric velocity obtained from the measurements based on both \ion{Si}{2}$\lambda$6355 line and spectral modeling, and 3) comparable explosion parameters. This analogy could imply a formation of a neutron star in the core-collapse of GRB\,171205A/SN\,2017iuk as previously suggested in GRB\,060218/SN\,2006aj. The properties of the host galaxy is discussed, which suggests that GRB\,171205A/SN\,2017iuk occurred in an early type (S0), high-mass, starforming galaxy with low specific SFR and solar metallicity., Comment: 9 pages, 7 figures and 1 table. To be published in ApJ
Published: 2018
Full Text: View/download PDF

15. A Global Photoionization Response to Prompt Emission and Outliers: Different Origin of Long Gamma-ray Bursts?

Author: Wang, J., Xin, L. P., Qiu, Y. L., Xu, D. W., Wei, J. Y., Wang, J., Xin, L. P., Qiu, Y. L., Xu, D. W., and Wei, J. Y.
Abstract: By using the line ratio \ion{C}{4}$\lambda1549$/\ion{C}{2}$\lambda1335$ as a tracer of ionization ratio of the interstellar medium (ISM) illuminated by a long gamma-ray burst (LGRB), we identify a global photoionization response of the ionization ratio to the photon luminosity of the prompt emission assessed by either $L_{\mathrm{iso}}/E_{\mathrm{peak}}$ or $L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$. The ionization ratio increases with both $L_{\mathrm{iso}}/E_{\mathrm{peak}}$ and $L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$ for a majority of the LGRBs in our sample, although there are a few outliers. The identified dependence of \ion{C}{4}/\ion{C}{2} on $L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$ suggests that the scatter of the widely accepted Amati relation is related with the ionization ratio in ISM. The outliers tend to have relatively high \ion{C}{4}/\ion{C}{2} values as well as relatively high \ion{C}{4}$\lambda1549$/\ion{Si}{4}$\lambda1403$ ratios, which suggests an existence of Wolf-Rayet stars in the environment of these LGRBs. We finally argue that the outliers and the LGRBs following the identified \ion{C}{4}/\ion{C}{2}$-L_{\mathrm{iso}}/E_{\mathrm{peak}}$ ($L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$) correlation might come from different progenitors with different local environments., Comment: 7 pages, 3 figures and 2 tables, to be published in ApJ
Published: 2018
Full Text: View/download PDF

16. Spectroscopy of the Type Ic Supernova SN\,2017iuk Associated with Low-redshift GRB\,171205A

Author: Wang, J., Zhu, Z. P., Xu, D., Xin, L. P., Deng, J. S., Qiu, Y. L., Qiu, P., Wang, H. J., Zhang, J. B., Wei, J. Y., Wang, J., Zhu, Z. P., Xu, D., Xin, L. P., Deng, J. S., Qiu, Y. L., Qiu, P., Wang, H. J., Zhang, J. B., and Wei, J. Y.
Abstract: We here report a spectroscopic monitor for the supernova SN\,2017iuk associated with the long-duration low-luminosity gamma-ray burst GRB\,171205A at a redshift of 0.037, which is up to now the third GRB-SN event away from us. Our spectroscopic observations and spectral analysis allow us to identify SN\,2017iuk as a typical broad-line type Ic SN. A comparison study suggests that the type-IcBL SN\,2017iuk resembles to SN\,2006aj in following aspects: 1) similar spectra at the nearby epochs, 2) comparable evolution of the photospheric velocity obtained from the measurements based on both \ion{Si}{2}$\lambda$6355 line and spectral modeling, and 3) comparable explosion parameters. This analogy could imply a formation of a neutron star in the core-collapse of GRB\,171205A/SN\,2017iuk as previously suggested in GRB\,060218/SN\,2006aj. The properties of the host galaxy is discussed, which suggests that GRB\,171205A/SN\,2017iuk occurred in an early type (S0), high-mass, starforming galaxy with low specific SFR and solar metallicity., Comment: 9 pages, 7 figures and 1 table. To be published in ApJ
Published: 2018
Full Text: View/download PDF

17. A Global Photoionization Response to Prompt Emission and Outliers: Different Origin of Long Gamma-ray Bursts?

Author: Wang, J., Xin, L. P., Qiu, Y. L., Xu, D. W., Wei, J. Y., Wang, J., Xin, L. P., Qiu, Y. L., Xu, D. W., and Wei, J. Y.
Abstract: By using the line ratio \ion{C}{4}$\lambda1549$/\ion{C}{2}$\lambda1335$ as a tracer of ionization ratio of the interstellar medium (ISM) illuminated by a long gamma-ray burst (LGRB), we identify a global photoionization response of the ionization ratio to the photon luminosity of the prompt emission assessed by either $L_{\mathrm{iso}}/E_{\mathrm{peak}}$ or $L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$. The ionization ratio increases with both $L_{\mathrm{iso}}/E_{\mathrm{peak}}$ and $L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$ for a majority of the LGRBs in our sample, although there are a few outliers. The identified dependence of \ion{C}{4}/\ion{C}{2} on $L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$ suggests that the scatter of the widely accepted Amati relation is related with the ionization ratio in ISM. The outliers tend to have relatively high \ion{C}{4}/\ion{C}{2} values as well as relatively high \ion{C}{4}$\lambda1549$/\ion{Si}{4}$\lambda1403$ ratios, which suggests an existence of Wolf-Rayet stars in the environment of these LGRBs. We finally argue that the outliers and the LGRBs following the identified \ion{C}{4}/\ion{C}{2}$-L_{\mathrm{iso}}/E_{\mathrm{peak}}$ ($L_{\mathrm{iso}}/E^2_{\mathrm{peak}}$) correlation might come from different progenitors with different local environments., Comment: 7 pages, 3 figures and 2 tables, to be published in ApJ
Published: 2018
Full Text: View/download PDF

18. A phylogenetic analysis of Apostasioideae (Orchidaceae) based on ITS, trn L-F and mat K sequences

Author: Kocyan, A., Qiu, Y.-L, Endress, P. K., Conti, E., Kocyan, A., Qiu, Y.-L, Endress, P. K., and Conti, E.
Abstract: The orchid subfamily Apostasioideae consists of two genera, Apostasia and Neuwiedia. To study the position of Apostasioideae within Orchidaceae and their intra- and intergeneric relationships, a molecular phylogenetic analysis has been conducted on the nuclear ITS region and the two plastid DNA regions trnL-F intron and matK. The two genera traditionally ascribed to Apostasioideae are each monophyletic. In Apostasia, A. nuda, with two stamens and no staminode, is sister to a clade comprising three species characterised by two stamens and one staminode. Within Neuwiedia, maximum parsimony analyses place N. zollingeri as sister to the clade formed by N. borneensis and N. veratrifolia. A family-wide phylogenetic analysis of matK sequences representing all proposed subfamilies of Orchidaceae produced five moderately to well-supported clades. One of these clades, Apostasioideae, is sister to the clade formed by Vanilloideae, Cypripedioideae, Orchidoideae and Epidendroideae. High transition-transversion ratio and the absence of stop codons in the individual sequences suggest that matK is at the transition from a possibly functional gene to a pseudogene in Apostasioideae, contrary to what is found in some other groups of Orchidaceae
Published: 2018

19. Broad-lined type Ic supernova iPTF16asu: A challenge to all popular models

Author: Wang, L. J., Wang, X. F., Cano, Z., Wang, S. Q., Liu, L. D., Dai, Z. G., Deng, J. S., Yu, H., Li, B., Song, L. M., Qiu, Y. L., Wei, J. Y., Wang, L. J., Wang, X. F., Cano, Z., Wang, S. Q., Liu, L. D., Dai, Z. G., Deng, J. S., Yu, H., Li, B., Song, L. M., Qiu, Y. L., and Wei, J. Y.
Abstract: It is well-known that ordinary supernovae (SNe) are powered by 56Ni cascade decay. Broad-lined type Ic SNe (SNe Ic-BL) are a subclass of SNe that are not all exclusively powered by 56Ni decay. It was suggested that some SNe Ic-BL are powered by magnetar spin-down. iPTF16asu is a peculiar broad-lined type Ic supernova discovered by the intermediate Palomar Transient Factory. With a rest-frame rise time of only 4 days, iPTF16asu challenges the existing popular models, for example, the radioactive heating (56Ni-only) and the magnetar+56Ni models. Here we show that this rapid rise could be attributed to interaction between the SN ejecta and a pre-existing circumstellar medium ejected by the progenitor during its final stages of evolution, while the late-time light curve can be better explained by energy input from a rapidly spinning magnetar. This model is a natural extension to the previous magnetar model. The mass-loss rate of the progenitor and ejecta mass are consistent with a progenitor that experienced a common envelope evolution in a binary. An alternative model for the early rapid rise of the light curve is the cooling of a shock propagating into an extended envelope of the progenitor. It is difficult at this stage to tell which model (interaction+magnetar+56Ni or cooling+magnetar+56Ni) is better for iPTF16asu. However, it is worth noting that the inferred envelope mass in the cooling+magnetar+56Ni is very high., Comment: 11 pages, 4 figures, 3 tables
Published: 2017
Full Text: View/download PDF

20. Broad-lined type Ic supernova iPTF16asu: A challenge to all popular models

Author: Wang, L. J., Wang, X. F., Cano, Z., Wang, S. Q., Liu, L. D., Dai, Z. G., Deng, J. S., Yu, H., Li, B., Song, L. M., Qiu, Y. L., Wei, J. Y., Wang, L. J., Wang, X. F., Cano, Z., Wang, S. Q., Liu, L. D., Dai, Z. G., Deng, J. S., Yu, H., Li, B., Song, L. M., Qiu, Y. L., and Wei, J. Y.
Abstract: It is well-known that ordinary supernovae (SNe) are powered by 56Ni cascade decay. Broad-lined type Ic SNe (SNe Ic-BL) are a subclass of SNe that are not all exclusively powered by 56Ni decay. It was suggested that some SNe Ic-BL are powered by magnetar spin-down. iPTF16asu is a peculiar broad-lined type Ic supernova discovered by the intermediate Palomar Transient Factory. With a rest-frame rise time of only 4 days, iPTF16asu challenges the existing popular models, for example, the radioactive heating (56Ni-only) and the magnetar+56Ni models. Here we show that this rapid rise could be attributed to interaction between the SN ejecta and a pre-existing circumstellar medium ejected by the progenitor during its final stages of evolution, while the late-time light curve can be better explained by energy input from a rapidly spinning magnetar. This model is a natural extension to the previous magnetar model. The mass-loss rate of the progenitor and ejecta mass are consistent with a progenitor that experienced a common envelope evolution in a binary. An alternative model for the early rapid rise of the light curve is the cooling of a shock propagating into an extended envelope of the progenitor. It is difficult at this stage to tell which model (interaction+magnetar+56Ni or cooling+magnetar+56Ni) is better for iPTF16asu. However, it is worth noting that the inferred envelope mass in the cooling+magnetar+56Ni is very high., Comment: 11 pages, 4 figures, 3 tables
Published: 2017
Full Text: View/download PDF

21. Evidence for magnetar formation in broad-lined type Ic supernovae 1998bw and 2002ap

Author: Wang, L. J., Yu, H., Liu, L. D., Wang, S. Q., Han, Y. H., Xu, D., Dai, Z. G., Qiu, Y. L., Wei, J. Y., Wang, L. J., Yu, H., Liu, L. D., Wang, S. Q., Han, Y. H., Xu, D., Dai, Z. G., Qiu, Y. L., and Wei, J. Y.
Abstract: Broad-lined type Ic supernovae (SNe Ic-BL) are peculiar stellar explosions that distinguish themselves from ordinary SNe. Some SNe Ic-BL are associated with long-duration (\gtrsim 2 s) gamma-ray bursts (GRBs). Black holes and magnetars are two types of compact objects that are hypothesized to be central engines of GRBs. In spite of decades of investigations, no direct evidence for the formation of black holes or magnetars has been found for GRBs so far. Here we report the finding that the early peak (t \lesssim 50 days) and late-time (t \gtrsim 300 days) slow decay displayed in the light curves of both SNe 1998bw (associated with GRB 980425) and 2002ap (not GRB-associated) can be attributed to magnetar spin-down with initial rotation period P0 \sim 20 ms, while the intermediate-time (50 \lesssim t \lesssim 300 days) linear decline is caused by radioactive decay of 56Ni. The connection between the early peak and late-time slow decline in the light curves is unexpected in alternative models. We thus suggest that GRB 980425 and SN 2002ap were powered by magnetars., Comment: 11 pages, 4 figures, ApJ accepted
Published: 2016
Full Text: View/download PDF

22. Evidence for magnetar formation in broad-lined type Ic supernovae 1998bw and 2002ap

Author: Wang, L. J., Yu, H., Liu, L. D., Wang, S. Q., Han, Y. H., Xu, D., Dai, Z. G., Qiu, Y. L., Wei, J. Y., Wang, L. J., Yu, H., Liu, L. D., Wang, S. Q., Han, Y. H., Xu, D., Dai, Z. G., Qiu, Y. L., and Wei, J. Y.
Abstract: Broad-lined type Ic supernovae (SNe Ic-BL) are peculiar stellar explosions that distinguish themselves from ordinary SNe. Some SNe Ic-BL are associated with long-duration (\gtrsim 2 s) gamma-ray bursts (GRBs). Black holes and magnetars are two types of compact objects that are hypothesized to be central engines of GRBs. In spite of decades of investigations, no direct evidence for the formation of black holes or magnetars has been found for GRBs so far. Here we report the finding that the early peak (t \lesssim 50 days) and late-time (t \gtrsim 300 days) slow decay displayed in the light curves of both SNe 1998bw (associated with GRB 980425) and 2002ap (not GRB-associated) can be attributed to magnetar spin-down with initial rotation period P0 \sim 20 ms, while the intermediate-time (50 \lesssim t \lesssim 300 days) linear decline is caused by radioactive decay of 56Ni. The connection between the early peak and late-time slow decline in the light curves is unexpected in alternative models. We thus suggest that GRB 980425 and SN 2002ap were powered by magnetars., Comment: 11 pages, 4 figures, ApJ accepted
Published: 2016
Full Text: View/download PDF

23. 18-Months Operation of Lunar-based Ultraviolet Telescope: A Highly Stable Photometric Performance

Author: Wang, J., Meng, X. M., Han, X. H., Cai, H. B., Cao, L., Deng, J. S., Qiu, Y. L., Wang, S., Wei, J. Y., Hu, J. Y., Wang, J., Meng, X. M., Han, X. H., Cai, H. B., Cao, L., Deng, J. S., Qiu, Y. L., Wang, S., Wei, J. Y., and Hu, J. Y.
Abstract: We here report the photometric performance of Lunar-based Ultraviolet telescope (LUT), the first robotic telescope working on the Moon, for its 18-months operation. In total, 17 IUE standards have been observed in 51 runs until June 2015, which returns a highly stable photometric performance during the past 18 months (i.e., no evolution of photometric performance with time). The magnitude zero point is determined to be $17.53\pm0.05$ mag, which is not only highly consistent with the results based on its first 6-months operation, but also independent on the spectral type of the standard from which the magnitude zero point is determined. The implications of this stable performance is discussed, and is useful for next generation lunar-based astronomical observations., Comment: 6 pages, 3 figures and 2 tables. To be published in Ap&SS
Published: 2015
Full Text: View/download PDF

24. An Unprecedented Constraint on Water Content in the Sunlit Lunar Exosphere Seen by Lunar-Based Ultraviolet Telescope of Chang'e-3 Mission

Author: Wang, J., Wu, C., Qiu, Y. L., Meng, X. M., Cai, H. B., Cao, L., Deng, J. S., Han, X. H., Wei, J. Y., Wang, J., Wu, C., Qiu, Y. L., Meng, X. M., Cai, H. B., Cao, L., Deng, J. S., Han, X. H., and Wei, J. Y.
Abstract: The content of $\mathrm{OH/H_2O}$ molecules in the tenuous exosphere of the Moon is still an open issue at present. We here report an unprecedented upper limit of the content of the OH radicals, which is obtained from the in-situ measurements carried out \rm by the Lunar-based Ultraviolet Telescope, a payload of Chinese Chang'e-3 mission. By analyzing the diffuse background in the images taken by the telescope, the column density and surface concentration of the OH radicals are inferred to be $<10^{11}\ \mathrm{cm^{-2}}$ and $<10^{4}\ \mathrm{cm^{-3}}$ (by assuming a hydrostatic equilibrium with a scale height of 100km), respectively, by assuming that the recorded background is fully contributed by their resonance fluorescence emission. The resulted concentration is lower than the previously reported value by about two orders of magnitude, and is close to the prediction of the sputtering model. In addition, the same measurements and method allow us to derive a surface concentration of $<10^{2}\ \mathrm{cm^{-3}}$ for the neutral magnesium, which is lower than the previously reported upper limit by about two orders of magnitude. These results are the best known of the OH (MgI) content in the lunar exosphere to date., Comment: To be published in P&SS, 19 pages, 4 figures and 2 tables
Published: 2015
Full Text: View/download PDF

25. 18-Months Operation of Lunar-based Ultraviolet Telescope: A Highly Stable Photometric Performance

Author: Wang, J., Meng, X. M., Han, X. H., Cai, H. B., Cao, L., Deng, J. S., Qiu, Y. L., Wang, S., Wei, J. Y., Hu, J. Y., Wang, J., Meng, X. M., Han, X. H., Cai, H. B., Cao, L., Deng, J. S., Qiu, Y. L., Wang, S., Wei, J. Y., and Hu, J. Y.
Abstract: We here report the photometric performance of Lunar-based Ultraviolet telescope (LUT), the first robotic telescope working on the Moon, for its 18-months operation. In total, 17 IUE standards have been observed in 51 runs until June 2015, which returns a highly stable photometric performance during the past 18 months (i.e., no evolution of photometric performance with time). The magnitude zero point is determined to be $17.53\pm0.05$ mag, which is not only highly consistent with the results based on its first 6-months operation, but also independent on the spectral type of the standard from which the magnitude zero point is determined. The implications of this stable performance is discussed, and is useful for next generation lunar-based astronomical observations., Comment: 6 pages, 3 figures and 2 tables. To be published in Ap&SS
Published: 2015
Full Text: View/download PDF

26. An Unprecedented Constraint on Water Content in the Sunlit Lunar Exosphere Seen by Lunar-Based Ultraviolet Telescope of Chang'e-3 Mission

Author: Wang, J., Wu, C., Qiu, Y. L., Meng, X. M., Cai, H. B., Cao, L., Deng, J. S., Han, X. H., Wei, J. Y., Wang, J., Wu, C., Qiu, Y. L., Meng, X. M., Cai, H. B., Cao, L., Deng, J. S., Han, X. H., and Wei, J. Y.
Abstract: The content of $\mathrm{OH/H_2O}$ molecules in the tenuous exosphere of the Moon is still an open issue at present. We here report an unprecedented upper limit of the content of the OH radicals, which is obtained from the in-situ measurements carried out \rm by the Lunar-based Ultraviolet Telescope, a payload of Chinese Chang'e-3 mission. By analyzing the diffuse background in the images taken by the telescope, the column density and surface concentration of the OH radicals are inferred to be $<10^{11}\ \mathrm{cm^{-2}}$ and $<10^{4}\ \mathrm{cm^{-3}}$ (by assuming a hydrostatic equilibrium with a scale height of 100km), respectively, by assuming that the recorded background is fully contributed by their resonance fluorescence emission. The resulted concentration is lower than the previously reported value by about two orders of magnitude, and is close to the prediction of the sputtering model. In addition, the same measurements and method allow us to derive a surface concentration of $<10^{2}\ \mathrm{cm^{-3}}$ for the neutral magnesium, which is lower than the previously reported upper limit by about two orders of magnitude. These results are the best known of the OH (MgI) content in the lunar exosphere to date., Comment: To be published in P&SS, 19 pages, 4 figures and 2 tables
Published: 2015
Full Text: View/download PDF

27. Photometric Calibration on Lunar-based Ultraviolet Telescope for Its First Six Months of Operation on Lunar Surface

Author: Wang, J., Cao, L., Meng, X. M., Cai, H. B., Deng, J. S., Han, X. H., Qiu, Y. L., Wang, F., Wang, S., Wen, W. B., Wu, C., Wei, J. Y., Hu, J. Y., Wang, J., Cao, L., Meng, X. M., Cai, H. B., Deng, J. S., Han, X. H., Qiu, Y. L., Wang, F., Wang, S., Wen, W. B., Wu, C., Wei, J. Y., and Hu, J. Y.
Abstract: We reported the photometric calibration of Lunar-based Ultraviolet telescope (LUT), the first robotic astronomical telescope working on the lunar surface, for its first six months of operation on the lunar surface. Two spectral datasets (set A and B) from near-ultraviolet (NUV) to optical band were constructed for 44 International Ultraviolet Explorer (IUE) standards, because of the LUT's relatively wide wavelength coverage. Set A were obtained by extrapolating the IUE NUV spectra ($\lambda<3200\AA$) to optical band basing upon the theoretical spectra of stellar atmosphere models. Set B were exactly the theoretical spectra from 2000\AA\ to 8000\AA\ extracted from the same model grid. In total, seven standards have been observed in 15 observational runs until May 2014. The calibration results show that the photometric performance of LUT is highly stable in its first six months of operation. The magnitude zero points obtained from the two spectral datasets are also consistent with each other, i.e., $\mathrm{zp=17.54\pm0.09}$mag (set A) and $\mathrm{zp=17.52\pm0.07}$mag (set B)., Comment: To appear in RAA, 9 pages, 3 tables, and 6 figures
Published: 2014

28. Photometric Calibration on Lunar-based Ultraviolet Telescope for Its First Six Months of Operation on Lunar Surface

Author: Wang, J., Cao, L., Meng, X. M., Cai, H. B., Deng, J. S., Han, X. H., Qiu, Y. L., Wang, F., Wang, S., Wen, W. B., Wu, C., Wei, J. Y., Hu, J. Y., Wang, J., Cao, L., Meng, X. M., Cai, H. B., Deng, J. S., Han, X. H., Qiu, Y. L., Wang, F., Wang, S., Wen, W. B., Wu, C., Wei, J. Y., and Hu, J. Y.
Abstract: We reported the photometric calibration of Lunar-based Ultraviolet telescope (LUT), the first robotic astronomical telescope working on the lunar surface, for its first six months of operation on the lunar surface. Two spectral datasets (set A and B) from near-ultraviolet (NUV) to optical band were constructed for 44 International Ultraviolet Explorer (IUE) standards, because of the LUT's relatively wide wavelength coverage. Set A were obtained by extrapolating the IUE NUV spectra ($\lambda<3200\AA$) to optical band basing upon the theoretical spectra of stellar atmosphere models. Set B were exactly the theoretical spectra from 2000\AA\ to 8000\AA\ extracted from the same model grid. In total, seven standards have been observed in 15 observational runs until May 2014. The calibration results show that the photometric performance of LUT is highly stable in its first six months of operation. The magnitude zero points obtained from the two spectral datasets are also consistent with each other, i.e., $\mathrm{zp=17.54\pm0.09}$mag (set A) and $\mathrm{zp=17.52\pm0.07}$mag (set B)., Comment: To appear in RAA, 9 pages, 3 tables, and 6 figures
Published: 2014

29. The shallow-decay phase in both optical and x-ray afterglows of Swift GRB 090529A: Energy injection into a wind-type medium?

Author: Xin, L. P., Pozanenko, A., Kann, D. A., Xu, D., Gorosabel, J., Leloudas, G., Wei, J. Y., Andreev, M., Qin, S. F., Ibrahimov, M., Han, X. H., Postigo, A. de Ugarte, Qiu, Y. L., Deng, J. S., Volnova, A., Jakobsson, P., Castro-Tirado, A. J., Aceituno, F., Fynbo, J. P. U., Wang, J., Sanchez-Ramirez, R., Kouprianov, V., Zheng, W. K., Tello, J. C., Wu, C., Xin, L. P., Pozanenko, A., Kann, D. A., Xu, D., Gorosabel, J., Leloudas, G., Wei, J. Y., Andreev, M., Qin, S. F., Ibrahimov, M., Han, X. H., Postigo, A. de Ugarte, Qiu, Y. L., Deng, J. S., Volnova, A., Jakobsson, P., Castro-Tirado, A. J., Aceituno, F., Fynbo, J. P. U., Wang, J., Sanchez-Ramirez, R., Kouprianov, V., Zheng, W. K., Tello, J. C., and Wu, C.
Abstract: The energy injection model is usually proposed to interpret the shallow-decay phase in Swift GRB X-ray afterglows. However, very few GRBs have simultaneous signatures of energy injection in their optical and X-ray afterglows. Here, we report optical observations of GRB 090529A from 2000 sec to $\sim10^6$ sec after the burst, in which an achromatic decay is seen at both wavelengths. The optical light curve shows a decay from 0.37 to 0.99 with a break at $\sim10^5$ sec. In the same time interval, the decay indices of the X-ray light curve changed from 0.04 to 1.2. Comparing these values with the closure relations, the segment after 3$\times10^{4}$ sec is consistent with the prediction of the forward shock in an ISM medium without any energy injection. The shallow-decay phase between 2000 to 3$\times10^{4}$ sec could be due to the external shock in a wind-type-like medium with an energy injection under the condition of $\nu_o < \nu_c < \nu_x$. However, the constraint of the spectral region is not well consistent with the multi-band observations. For this shallow-decay phase, other models are also possible, such as energy injection with evolving microphysical parameters, or a jet viewed off-axis,etc., Comment: 19pages,2gigures, accepted by MNRAS
Published: 2012
Full Text: View/download PDF

30. The shallow-decay phase in both optical and x-ray afterglows of Swift GRB 090529A: Energy injection into a wind-type medium?

Author: Xin, L. P., Pozanenko, A., Kann, D. A., Xu, D., Gorosabel, J., Leloudas, G., Wei, J. Y., Andreev, M., Qin, S. F., Ibrahimov, M., Han, X. H., Postigo, A. de Ugarte, Qiu, Y. L., Deng, J. S., Volnova, A., Jakobsson, P., Castro-Tirado, A. J., Aceituno, F., Fynbo, J. P. U., Wang, J., Sanchez-Ramirez, R., Kouprianov, V., Zheng, W. K., Tello, J. C., Wu, C., Xin, L. P., Pozanenko, A., Kann, D. A., Xu, D., Gorosabel, J., Leloudas, G., Wei, J. Y., Andreev, M., Qin, S. F., Ibrahimov, M., Han, X. H., Postigo, A. de Ugarte, Qiu, Y. L., Deng, J. S., Volnova, A., Jakobsson, P., Castro-Tirado, A. J., Aceituno, F., Fynbo, J. P. U., Wang, J., Sanchez-Ramirez, R., Kouprianov, V., Zheng, W. K., Tello, J. C., and Wu, C.
Abstract: The energy injection model is usually proposed to interpret the shallow-decay phase in Swift GRB X-ray afterglows. However, very few GRBs have simultaneous signatures of energy injection in their optical and X-ray afterglows. Here, we report optical observations of GRB 090529A from 2000 sec to $\sim10^6$ sec after the burst, in which an achromatic decay is seen at both wavelengths. The optical light curve shows a decay from 0.37 to 0.99 with a break at $\sim10^5$ sec. In the same time interval, the decay indices of the X-ray light curve changed from 0.04 to 1.2. Comparing these values with the closure relations, the segment after 3$\times10^{4}$ sec is consistent with the prediction of the forward shock in an ISM medium without any energy injection. The shallow-decay phase between 2000 to 3$\times10^{4}$ sec could be due to the external shock in a wind-type-like medium with an energy injection under the condition of $\nu_o < \nu_c < \nu_x$. However, the constraint of the spectral region is not well consistent with the multi-band observations. For this shallow-decay phase, other models are also possible, such as energy injection with evolving microphysical parameters, or a jet viewed off-axis,etc., Comment: 19pages,2gigures, accepted by MNRAS
Published: 2012
Full Text: View/download PDF

31. Very Early Photometry of SN 1998S: Physical Parameters and Date of Explosion

Author: Poon, H., Pun, J. C. S., Lam, T. Y., Qiu, Y. L., Wei, J. Y., Poon, H., Pun, J. C. S., Lam, T. Y., Qiu, Y. L., and Wei, J. Y.
Abstract: Context. We present very early optical lightcurves beginning 10 days before maximum of the Type IIn supernova 1998S, covering the first four months after discovery. Aims. We examine the light evolution and try to compare the lightcurves to two analytical models(Nakar & Sari(2010) and Rabinak & Waxman(2011)) for a red supergiant star. Methods. The photometry was carried at the 60-cm telescope of the Xinglong Station of China. Broadband filters Johnsons B, V and Cousins R were used. Results. The magnitude rose for the first few days and then dropped slowly afterwards. The two different models we use can fit the early lightcurves very well. The explosion date derived from the models is within the range of 1998 March 1.34 - 2.64(JD 2450873.84 - JD 2450875.14.) The radius of the progenitor is found to be ~ 300 Rsun and ~ 2000 Rsun for the model of Nakar & Sari(2010) and Rabinak & Waxman(2011) respectively. The constraint on mass and energy is not strong. The ranges of these two parameters are within that of a red supergiant., Comment: 6 pages, 8 figures
Published: 2011

32. Lunar Exosphere Influence on Lunar-based Near-ultraviolet Astronomical Observations

Author: Wang, J., deng, J. S., Cui, J., Cao, L., Qiu, Y. L., Wei, J. Y., Wang, J., deng, J. S., Cui, J., Cao, L., Qiu, Y. L., and Wei, J. Y.
Abstract: The potential effect of the lunar exosphere on the near-ultraviolet sky background emission is predicted for Lunar-based Ultraviolet Telescope (LUT: a funded Chinese scientific payload for the Chang'e-III mission). Using the upper limit on the OH concentration inferred from the recent MIP CHACE results, our calculations show that the sky brightness due to the illuminated exosphere is $<8.7\ \mathrm{photon\ s^{-1}\ cm^{-2}\ arcsec^{-2}}$ within the wavelength range 245-340 nm. By evaluating the signal-to-noise ratios of observations of an AB=13 mag point source at a series of sky background levels, our analysis indicates that the detection performance of LUT can be moderately degraded by the lunar exosphere emission in most cases. An AB=13 mag point source can still be detected by the telescope at a signal-to-noise ratio more than 8 when the OH concentration is less than $2\times10^8\ \mathrm{molecules\ cm^{-3}}$. However, the effect on the performance is considerable when the exosphere is as dense as suggested by CHACE., Comment: 21 pages, 5 tables, and 1 figure, to be published in AdSpR
Published: 2011
Full Text: View/download PDF

33. Very Early Photometry of SN 1998S: Physical Parameters and Date of Explosion

Author: Poon, H., Pun, J. C. S., Lam, T. Y., Qiu, Y. L., Wei, J. Y., Poon, H., Pun, J. C. S., Lam, T. Y., Qiu, Y. L., and Wei, J. Y.
Abstract: Context. We present very early optical lightcurves beginning 10 days before maximum of the Type IIn supernova 1998S, covering the first four months after discovery. Aims. We examine the light evolution and try to compare the lightcurves to two analytical models(Nakar & Sari(2010) and Rabinak & Waxman(2011)) for a red supergiant star. Methods. The photometry was carried at the 60-cm telescope of the Xinglong Station of China. Broadband filters Johnsons B, V and Cousins R were used. Results. The magnitude rose for the first few days and then dropped slowly afterwards. The two different models we use can fit the early lightcurves very well. The explosion date derived from the models is within the range of 1998 March 1.34 - 2.64(JD 2450873.84 - JD 2450875.14.) The radius of the progenitor is found to be ~ 300 Rsun and ~ 2000 Rsun for the model of Nakar & Sari(2010) and Rabinak & Waxman(2011) respectively. The constraint on mass and energy is not strong. The ranges of these two parameters are within that of a red supergiant., Comment: 6 pages, 8 figures
Published: 2011

34. Lunar Exosphere Influence on Lunar-based Near-ultraviolet Astronomical Observations

Author: Wang, J., deng, J. S., Cui, J., Cao, L., Qiu, Y. L., Wei, J. Y., Wang, J., deng, J. S., Cui, J., Cao, L., Qiu, Y. L., and Wei, J. Y.
Abstract: The potential effect of the lunar exosphere on the near-ultraviolet sky background emission is predicted for Lunar-based Ultraviolet Telescope (LUT: a funded Chinese scientific payload for the Chang'e-III mission). Using the upper limit on the OH concentration inferred from the recent MIP CHACE results, our calculations show that the sky brightness due to the illuminated exosphere is $<8.7\ \mathrm{photon\ s^{-1}\ cm^{-2}\ arcsec^{-2}}$ within the wavelength range 245-340 nm. By evaluating the signal-to-noise ratios of observations of an AB=13 mag point source at a series of sky background levels, our analysis indicates that the detection performance of LUT can be moderately degraded by the lunar exosphere emission in most cases. An AB=13 mag point source can still be detected by the telescope at a signal-to-noise ratio more than 8 when the OH concentration is less than $2\times10^8\ \mathrm{molecules\ cm^{-3}}$. However, the effect on the performance is considerable when the exosphere is as dense as suggested by CHACE., Comment: 21 pages, 5 tables, and 1 figure, to be published in AdSpR
Published: 2011
Full Text: View/download PDF

35. GRB 070518: A Gamma-ray Burst with Optically Dim Luminosity

Author: Xin, L. P., Zheng, W. K., Wang, J., Deng, J. S., Urata, Y., Qiu, Y. L., Huang, K. Y., Hu, J. Y., Wei, J. Y., Xin, L. P., Zheng, W. K., Wang, J., Deng, J. S., Urata, Y., Qiu, Y. L., Huang, K. Y., Hu, J. Y., and Wei, J. Y.
Abstract: We present our optical observations of {\em Swift} GRB 070518 afterglow obtained at the 0.8-m Tsinghua University-National Astronomical Observatory of China telescope (TNT) at Xinglong Observatory. Our follow-up observations were performed from 512 sec after the burst trigger. With the upper limit of redshift $\sim$0.7, GRB 070518 is found to be an optically dim burst. The spectra indices $\beta_{ox}$ of optical to X-ray are slightly larger than 0.5, which implies the burst might be a dark burst. The extinction $A_{V}$ of the host galaxy is 3.2 mag inferred from the X-ray hydrogen column density with Galactic extinction law, and 0.3 mag with SMC extinction law. Also, it is similar to three other low-redshift optically dim bursts, which belong to XRR or XRF, and mid-term duration($T_{90}<10$, except for GRB 070419A, $T_{90}$=116s). Moreover, its $R$ band afterglow flux is well fitted by a single power-law with an index of 0.87. The optical afterglow and the X-ray afterglow in the normal segment might have the same mechanism, as they are consistent with the prediction of the classical external shock model. Besides, GRB 070518 agrees with Amati relation under reasonable assumptions. The Ghirlanda relation is also tested with the burst., Comment: 8 pages, 4 figures, MNRAS accepted
Published: 2009
Full Text: View/download PDF

36. GRB 070518: A Gamma-ray Burst with Optically Dim Luminosity

Author: Xin, L. P., Zheng, W. K., Wang, J., Deng, J. S., Urata, Y., Qiu, Y. L., Huang, K. Y., Hu, J. Y., Wei, J. Y., Xin, L. P., Zheng, W. K., Wang, J., Deng, J. S., Urata, Y., Qiu, Y. L., Huang, K. Y., Hu, J. Y., and Wei, J. Y.
Abstract: We present our optical observations of {\em Swift} GRB 070518 afterglow obtained at the 0.8-m Tsinghua University-National Astronomical Observatory of China telescope (TNT) at Xinglong Observatory. Our follow-up observations were performed from 512 sec after the burst trigger. With the upper limit of redshift $\sim$0.7, GRB 070518 is found to be an optically dim burst. The spectra indices $\beta_{ox}$ of optical to X-ray are slightly larger than 0.5, which implies the burst might be a dark burst. The extinction $A_{V}$ of the host galaxy is 3.2 mag inferred from the X-ray hydrogen column density with Galactic extinction law, and 0.3 mag with SMC extinction law. Also, it is similar to three other low-redshift optically dim bursts, which belong to XRR or XRF, and mid-term duration($T_{90}<10$, except for GRB 070419A, $T_{90}$=116s). Moreover, its $R$ band afterglow flux is well fitted by a single power-law with an index of 0.87. The optical afterglow and the X-ray afterglow in the normal segment might have the same mechanism, as they are consistent with the prediction of the classical external shock model. Besides, GRB 070518 agrees with Amati relation under reasonable assumptions. The Ghirlanda relation is also tested with the burst., Comment: 8 pages, 4 figures, MNRAS accepted
Published: 2009
Full Text: View/download PDF

37. Very early multi-color observations of the plateau phase of GRB 041006 afterglow

Author: Urata, Y., Huang, K. Y., Qiu, Y. L., Hu, J., Kuo, P. H., Tamagawa, T., Ip, W. H., Kinoshita, D., Fukushi, H., Isogai, M., Miyata, T., Nakada, Y., Aoki, T., Soyano, T., Tarusawa, K., Mito, H., Onda, K., Ibrahimov, M., Pozanenko, A., Makishima, K., Urata, Y., Huang, K. Y., Qiu, Y. L., Hu, J., Kuo, P. H., Tamagawa, T., Ip, W. H., Kinoshita, D., Fukushi, H., Isogai, M., Miyata, T., Nakada, Y., Aoki, T., Soyano, T., Tarusawa, K., Mito, H., Onda, K., Ibrahimov, M., Pozanenko, A., and Makishima, K.
Abstract: Observations of the optical afterglow of GRB 041006 with the Kiso Observatory 1.05 m Schmidt telescope, the Lulin Observatory 1.0 m telescope and the Xinglong Observatory 0.6 m telescope. Three-bands (B, V and R) of photometric data points were obtained on 2004 October 6, 0.025-0.329 days after the burst. These very early multi band light curves imply the existence of a color dependent plateau phase. The B-band light curve shows a clear plateau at around 0.03 days after the burst. The R band light curve shows the hint of a plateau, or a possible slope change, at around 0.1 days after the burst. The overall behavior of these multi-band light curves may be interpreted in terms of the sum of two separate components, one showing a monotonic decay the other exhibiting a rising and a falling phase, as described by the standard afterglow model., Comment: 11 pages, 2 figures, Accepted to ApJ Letters
Published: 2006
Full Text: View/download PDF

38. Very early multi-color observations of the plateau phase of GRB 041006 afterglow

Author: Urata, Y., Huang, K. Y., Qiu, Y. L., Hu, J., Kuo, P. H., Tamagawa, T., Ip, W. H., Kinoshita, D., Fukushi, H., Isogai, M., Miyata, T., Nakada, Y., Aoki, T., Soyano, T., Tarusawa, K., Mito, H., Onda, K., Ibrahimov, M., Pozanenko, A., Makishima, K., Urata, Y., Huang, K. Y., Qiu, Y. L., Hu, J., Kuo, P. H., Tamagawa, T., Ip, W. H., Kinoshita, D., Fukushi, H., Isogai, M., Miyata, T., Nakada, Y., Aoki, T., Soyano, T., Tarusawa, K., Mito, H., Onda, K., Ibrahimov, M., Pozanenko, A., and Makishima, K.
Abstract: Observations of the optical afterglow of GRB 041006 with the Kiso Observatory 1.05 m Schmidt telescope, the Lulin Observatory 1.0 m telescope and the Xinglong Observatory 0.6 m telescope. Three-bands (B, V and R) of photometric data points were obtained on 2004 October 6, 0.025-0.329 days after the burst. These very early multi band light curves imply the existence of a color dependent plateau phase. The B-band light curve shows a clear plateau at around 0.03 days after the burst. The R band light curve shows the hint of a plateau, or a possible slope change, at around 0.1 days after the burst. The overall behavior of these multi-band light curves may be interpreted in terms of the sum of two separate components, one showing a monotonic decay the other exhibiting a rising and a falling phase, as described by the standard afterglow model., Comment: 11 pages, 2 figures, Accepted to ApJ Letters
Published: 2006
Full Text: View/download PDF

39. A phylogenetic analysis of Apostasioideae (Orchidaceae) based on ITS, trnL-F and matK sequences

Author: Kocyan, A, Qiu, Y-L, Endress, P K; https://orcid.org/0000-0002-4813-1734, Conti, E, Kocyan, A, Qiu, Y-L, Endress, P K; https://orcid.org/0000-0002-4813-1734, and Conti, E
Abstract: The orchid subfamily Apostasioideae consists of two genera, Apostasia and Neuwiedia. To study the position of Apostasioideae within Orchidaceae and their intra- and intergeneric relationships, a molecular phylogenetic analysis has been conducted on the nuclear ITS region and the two plastid DNA regions trnL-F intron and matK. The two genera traditionally ascribed to Apostasioideae are each monophyletic. In Apostasia, A. nuda, with two stamens and no staminode, is sister to a clade comprising three species characterised by two stamens and one staminode. Within Neuwiedia, maximum parsimony analyses place N. zollingeri as sister to the clade formed by N. borneensis and N. veratrifolia. A family-wide phylogenetic analysis of matK sequences representing all proposed subfamilies of Orchidaceae produced five moderately to well-supported clades. One of these clades, Apostasioideae, is sister to the clade formed by Vanilloideae, Cypripedioideae, Orchidoideae and Epidendroideae. High transition-transversion ratio and the absence of stop codons in the individual sequences suggest that matK is at the transition from a possibly functional gene to a pseudogene in Apostasioideae, contrary to what is found in some other groups of Orchidaceae
Published: 2004

40. Phylogenetic inference in Rafflesiales: the influence of rate heterogeneity and horizontal gene transfer

Author: Nickrent, D L, Blarer, A, Qiu, Y L, Vidal-Russell, R, Anderson, F E, Nickrent, D L, Blarer, A, Qiu, Y L, Vidal-Russell, R, and Anderson, F E
Abstract: BACKGROUND: The phylogenetic relationships among the holoparasites of Rafflesiales have remained enigmatic for over a century. Recent molecular phylogenetic studies using the mitochondrial matR gene placed Rafflesia, Rhizanthes and Sapria (Rafflesiaceae s. str.) in the angiosperm order Malpighiales and Mitrastema (Mitrastemonaceae) in Ericales. These phylogenetic studies did not, however, sample two additional groups traditionally classified within Rafflesiales (Apodantheaceae and Cytinaceae). Here we provide molecular phylogenetic evidence using DNA sequence data from mitochondrial and nuclear genes for representatives of all genera in Rafflesiales. RESULTS: Our analyses indicate that the phylogenetic affinities of the large-flowered clade and Mitrastema, ascertained using mitochondrial matR, are congruent with results from nuclear SSU rDNA when these data are analyzed using maximum likelihood and Bayesian methods. The relationship of Cytinaceae to Malvales was recovered in all analyses. Relationships between Apodanthaceae and photosynthetic angiosperms varied depending upon the data partition: Malvales (3-gene), Cucurbitales (matR) or Fabales (atp1). The latter incongruencies suggest that horizontal gene transfer (HGT) may be affecting the mitochondrial gene topologies. The lack of association between Mitrastema and Ericales using atp1 is suggestive of HGT, but greater sampling within eudicots is needed to test this hypothesis further. CONCLUSIONS: Rafflesiales are not monophyletic but composed of three or four independent lineages (families): Rafflesiaceae, Mitrastemonaceae, Apodanthaceae and Cytinaceae. Long-branch attraction appears to be misleading parsimony analyses of nuclear small-subunit rDNA data, but model-based methods (maximum likelihood and Bayesian analyses) recover a topology that is congruent with the mitochondrial matR gene tree, thus providing compelling evidence for organismal relationships. Horizontal gene transfer appears to be influencing onl
Published: 2004

41. A Time Evolution Study of the Superhumps of the Dwarf Nova 1RXS J232953.9+062814 by Wavelet Transform

Author: Zhou, A. -Y., Qiu, Y. -L., Zhou, A. -Y., and Qiu, Y. -L.
Abstract: The time evolution behaviour of the superhumps of the dwarf nova 1RXS J232953.9+062814 is investigated with the wavelet analysis method. On the basis of two nights CCD photometry performed during its first superoutburst as well as other published brightness data, we reveal the superhump's time-dependence as a function of periods and time. Our light curves, which phased in the rapid decay ending portion of the superoutburst and in the dawn of a following normal outburst, are important to help trace the superhump evolution for the star. Evident amplitude variations of the superhumps, reflecting the fading of outbursts, are detected. The general profile of brightness fading over the outbursts roughly followed an exponential decay law or a form of a five-order polynomial. Both the superhump period and the orbital period of the binary system are detected in the present data. We obtain P_sh=0.04575(5) d and P_orb=0.04496(5) d. They agree with the existing values based on additional data. The two periods exchanged their roles during the superhump evolution., Comment: 7 pages, 9 figures, submitted to Astronomy & Astrophysics
Published: 2002
Full Text: View/download PDF

42. The Type Ic Hypernova SN 2002ap

Author: Mazzali, P. A., Deng, J., Maeda, K., Nomoto, K., Umeda, H., Hatano, K., Iwamoto, K., Yoshii, Y., Kobayashi, Y., Minezaki, T., Doi, M., Enya, K., Tomita, H., Smartt, S. J., Kinugasa, K., Kawakita, H., Ayani, K., Kawabata, T., Yamaoka, H., Qiu, Y. L., Motohara, K., Gerardy, C. L., Fesen, R., Kawabata, K. S., Iye, M., Kashikawa, N., Kosugi, G., Ohyama, Y., Takada-Hidai, M., Zhao, G., Chornock, R., Filippenko, A. V., Benetti, S., Turatto, M., Mazzali, P. A., Deng, J., Maeda, K., Nomoto, K., Umeda, H., Hatano, K., Iwamoto, K., Yoshii, Y., Kobayashi, Y., Minezaki, T., Doi, M., Enya, K., Tomita, H., Smartt, S. J., Kinugasa, K., Kawakita, H., Ayani, K., Kawabata, T., Yamaoka, H., Qiu, Y. L., Motohara, K., Gerardy, C. L., Fesen, R., Kawabata, K. S., Iye, M., Kashikawa, N., Kosugi, G., Ohyama, Y., Takada-Hidai, M., Zhao, G., Chornock, R., Filippenko, A. V., Benetti, S., and Turatto, M.
Abstract: Photometric and spectroscopic data of the energetic Type Ic supernova (SN) 2002ap are presented, and the properties of the SN are investigated through models of its spectral evolution and its light curve. The SN is spectroscopically similar to the "hypernova" SN 1997ef. However, its kinetic energy [$\sim (4-10) \times 10^{51}$ erg] and the mass ejected (2.5-5 $M_{\odot}$) are smaller, resulting in a faster-evolving light curve. The SN synthesized $\sim 0.07 M_{\odot}$ of $^{56}$Ni, and its peak luminosity was similar to that of normal SNe. Brightness alone should not be used to define a hypernova, whose defining character, namely very broad spectral features, is the result of a high kinetic energy. The likely main-sequence mass of the progenitor star was 20-25 $M_{\odot}$, which is also lower than that of both hypernovae SNe 1997ef and 1998bw. SN 2002ap appears to lie at the low-energy and low-mass end of the hypernova sequence as it is known so far. Observations of the nebular spectrum, which is expected to dominate by summer 2002, are necessary to confirm these values., Comment: 10 pages, 4 figures, accepted for publication in ApJL, 30 April 2002 (minor changes to match the accepted version, with figures being colored)
Published: 2002
Full Text: View/download PDF

43. A Time Evolution Study of the Superhumps of the Dwarf Nova 1RXS J232953.9+062814 by Wavelet Transform

Author: Zhou, A. -Y., Qiu, Y. -L., Zhou, A. -Y., and Qiu, Y. -L.
Abstract: The time evolution behaviour of the superhumps of the dwarf nova 1RXS J232953.9+062814 is investigated with the wavelet analysis method. On the basis of two nights CCD photometry performed during its first superoutburst as well as other published brightness data, we reveal the superhump's time-dependence as a function of periods and time. Our light curves, which phased in the rapid decay ending portion of the superoutburst and in the dawn of a following normal outburst, are important to help trace the superhump evolution for the star. Evident amplitude variations of the superhumps, reflecting the fading of outbursts, are detected. The general profile of brightness fading over the outbursts roughly followed an exponential decay law or a form of a five-order polynomial. Both the superhump period and the orbital period of the binary system are detected in the present data. We obtain P_sh=0.04575(5) d and P_orb=0.04496(5) d. They agree with the existing values based on additional data. The two periods exchanged their roles during the superhump evolution., Comment: 7 pages, 9 figures, submitted to Astronomy & Astrophysics
Published: 2002
Full Text: View/download PDF

44. The Type Ic Hypernova SN 2002ap

Author: Mazzali, P. A., Deng, J., Maeda, K., Nomoto, K., Umeda, H., Hatano, K., Iwamoto, K., Yoshii, Y., Kobayashi, Y., Minezaki, T., Doi, M., Enya, K., Tomita, H., Smartt, S. J., Kinugasa, K., Kawakita, H., Ayani, K., Kawabata, T., Yamaoka, H., Qiu, Y. L., Motohara, K., Gerardy, C. L., Fesen, R., Kawabata, K. S., Iye, M., Kashikawa, N., Kosugi, G., Ohyama, Y., Takada-Hidai, M., Zhao, G., Chornock, R., Filippenko, A. V., Benetti, S., Turatto, M., Mazzali, P. A., Deng, J., Maeda, K., Nomoto, K., Umeda, H., Hatano, K., Iwamoto, K., Yoshii, Y., Kobayashi, Y., Minezaki, T., Doi, M., Enya, K., Tomita, H., Smartt, S. J., Kinugasa, K., Kawakita, H., Ayani, K., Kawabata, T., Yamaoka, H., Qiu, Y. L., Motohara, K., Gerardy, C. L., Fesen, R., Kawabata, K. S., Iye, M., Kashikawa, N., Kosugi, G., Ohyama, Y., Takada-Hidai, M., Zhao, G., Chornock, R., Filippenko, A. V., Benetti, S., and Turatto, M.
Abstract: Photometric and spectroscopic data of the energetic Type Ic supernova (SN) 2002ap are presented, and the properties of the SN are investigated through models of its spectral evolution and its light curve. The SN is spectroscopically similar to the "hypernova" SN 1997ef. However, its kinetic energy [$\sim (4-10) \times 10^{51}$ erg] and the mass ejected (2.5-5 $M_{\odot}$) are smaller, resulting in a faster-evolving light curve. The SN synthesized $\sim 0.07 M_{\odot}$ of $^{56}$Ni, and its peak luminosity was similar to that of normal SNe. Brightness alone should not be used to define a hypernova, whose defining character, namely very broad spectral features, is the result of a high kinetic energy. The likely main-sequence mass of the progenitor star was 20-25 $M_{\odot}$, which is also lower than that of both hypernovae SNe 1997ef and 1998bw. SN 2002ap appears to lie at the low-energy and low-mass end of the hypernova sequence as it is known so far. Observations of the nebular spectrum, which is expected to dominate by summer 2002, are necessary to confirm these values., Comment: 10 pages, 4 figures, accepted for publication in ApJL, 30 April 2002 (minor changes to match the accepted version, with figures being colored)
Published: 2002
Full Text: View/download PDF

45. A High Intrinsic Peculiarity Rate Among Type Ia Supernovae

Author: Li, Weidong, Filippenko, Alexei V., Treffers, R. R., Riess, A. G., Hu, Jingyao, Qiu, Y. L., Li, Weidong, Filippenko, Alexei V., Treffers, R. R., Riess, A. G., Hu, Jingyao, and Qiu, Y. L.
Abstract: We have compiled a sample of 45 Type Ia supernovae (SNe Ia) discovered by the Lick Observatory Supernova Search (LOSS) and the Beijing Astronomical Observatory Supernova Survey (BAOSS), and determined the rate of spectroscopically peculiar SNe Ia (i.e., SN 1986G-like, SN 1991bg-like, and SN 1991T-like objects) and the luminosity function of SNe Ia. Because of the nature of the two surveys (distance-limited with small baselines and deep limiting magnitudes), nearly all SNe Ia have been discovered in the sample galaxies of LOSS and BAOSS; thus, the observed peculiarity rate and luminosity function of SNe Ia are intrinsic. We find that 36$\pm$9% of nearby SNe Ia are peculiar; specifically, the luminosity function of SNe Ia consists of 20% SN 1991T-like, 64% normal, and 16% SN 1991bg-like objects. We have compared our results to those found by earlier studies, and to those found at high redshift. The apparent dearth of SN 1991T-like objects at high redshift may be due to extinction, and especially to the difficulty of recognizing them from spectra obtained past maximum brightness or from spectra with low signal-to-noise ratios. Implications of the high peculiarity rate for the progenitor systems of SNe Ia are also briefly discussed., Comment: 20 pages, 7 figures, accepted for publication in the ApJ
Published: 2000
Full Text: View/download PDF

46. Spectrum Analysis of the Type Ib Supernova 1999dn: Probable Identifications of C II and H-alpha

Author: Deng, J. S., Qiu, Y. L., Hu, J. Y., Hatano, K., Branch, D., Deng, J. S., Qiu, Y. L., Hu, J. Y., Hatano, K., and Branch, D.
Abstract: Low resolution spectra of SN 1999dn at early times are presented and compared with synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW. We find that the spectra of SN 1999dn strongly resemble those of SN 1997X and SN 1984L, and hence we classify it as a Type Ib event. Line-identifications are established through spectrum synthesis. Strong evidence of both H-alpha and C II 6580 is found. We infer that H-alpha appears first, before the time of maximum brightness, and then is blended with and finally overwhelmed by the C II line after maximum; this favors a thin high-velocity hydrogen skin in this Type Ib supernova., Comment: 15 pages, 3 figures. Accepted for publication in ApJ
Published: 2000
Full Text: View/download PDF

47. Spectrum Analysis of the Type Ib Supernova 1999dn: Probable Identifications of C II and H-alpha

Author: Deng, J. S., Qiu, Y. L., Hu, J. Y., Hatano, K., Branch, D., Deng, J. S., Qiu, Y. L., Hu, J. Y., Hatano, K., and Branch, D.
Abstract: Low resolution spectra of SN 1999dn at early times are presented and compared with synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW. We find that the spectra of SN 1999dn strongly resemble those of SN 1997X and SN 1984L, and hence we classify it as a Type Ib event. Line-identifications are established through spectrum synthesis. Strong evidence of both H-alpha and C II 6580 is found. We infer that H-alpha appears first, before the time of maximum brightness, and then is blended with and finally overwhelmed by the C II line after maximum; this favors a thin high-velocity hydrogen skin in this Type Ib supernova., Comment: 15 pages, 3 figures. Accepted for publication in ApJ
Published: 2000
Full Text: View/download PDF

48. A High Intrinsic Peculiarity Rate Among Type Ia Supernovae

Author: Li, Weidong, Filippenko, Alexei V., Treffers, R. R., Riess, A. G., Hu, Jingyao, Qiu, Y. L., Li, Weidong, Filippenko, Alexei V., Treffers, R. R., Riess, A. G., Hu, Jingyao, and Qiu, Y. L.
Abstract: We have compiled a sample of 45 Type Ia supernovae (SNe Ia) discovered by the Lick Observatory Supernova Search (LOSS) and the Beijing Astronomical Observatory Supernova Survey (BAOSS), and determined the rate of spectroscopically peculiar SNe Ia (i.e., SN 1986G-like, SN 1991bg-like, and SN 1991T-like objects) and the luminosity function of SNe Ia. Because of the nature of the two surveys (distance-limited with small baselines and deep limiting magnitudes), nearly all SNe Ia have been discovered in the sample galaxies of LOSS and BAOSS; thus, the observed peculiarity rate and luminosity function of SNe Ia are intrinsic. We find that 36$\pm$9% of nearby SNe Ia are peculiar; specifically, the luminosity function of SNe Ia consists of 20% SN 1991T-like, 64% normal, and 16% SN 1991bg-like objects. We have compared our results to those found by earlier studies, and to those found at high redshift. The apparent dearth of SN 1991T-like objects at high redshift may be due to extinction, and especially to the difficulty of recognizing them from spectra obtained past maximum brightness or from spectra with low signal-to-noise ratios. Implications of the high peculiarity rate for the progenitor systems of SNe Ia are also briefly discussed., Comment: 20 pages, 7 figures, accepted for publication in the ApJ
Published: 2000
Full Text: View/download PDF

49. A High Peculiarity Rate for Type Ia SNe

Author: Li, W. D., Filippenko, A. V., Riess, A. G., Hu, J. Y., Qiu, Y. L., Li, W. D., Filippenko, A. V., Riess, A. G., Hu, J. Y., and Qiu, Y. L.
Abstract: We have compiled a sample of 90 SNe Ia from 1997 to 1999 (up to SN 1999da) and studied the peculiarity rate of SN 1991T, SN 1991bg and SN 1986G-like objects. A Monte Carlo code is written to study the observational biases involved in the evaluation of the intrinsic peculiarity rate of SNe Ia. We found that the peculiarity rate of SNe Ia is higher than 30% and the luminosity function of SNe Ia is flat., Comment: 4 pages, 2 figure, Submitted to the proceedings of the 10th Annual October Astrophysics Conference in Maryland on Cosmic Explosions
Published: 1999
Full Text: View/download PDF

50. The Type Ia Supernova 1997br in ESO 576-G40

Author: Li, W. D., Qiu, Y. L., Zhu, X. H., Hu, J. Y., Richmond, M. W., Treffers, A. V. Filippenko R. R., Peng, C. Y., Leonard, D. C., Li, W. D., Qiu, Y. L., Zhu, X. H., Hu, J. Y., Richmond, M. W., Treffers, A. V. Filippenko R. R., Peng, C. Y., and Leonard, D. C.
Abstract: The peculiar type Ia supernova SN 1997br in ESO 576-G40 was extensively observed at Beijing Astronomical Observatory and Lick Observatory. In this paper, we present and discuss the BVRI photometry and the spectra collected over 3 months, beginning 9 days before maximum brightness. The light curves of SN 1997br are similar to those of SN 1991T, with slow decline rates after the B maximum. Well-sampled data before the B maximum show unambiguously that SN 1997br rises more slowly and has a wider peak than normal type Ia supernovae. The optical color evolution of SN 1997br is also similar to that of SN 1991T. We estimate the extinction of SN 1997br to be E(B-V) = 0.35+/-0.10 mag by comparing its BVRI light curves with those of SN 1991T and by measureing the equivalent width of interstellar Na I D absorption lines. We have conducted a thorough comparison of the spectroscopic evolution of SN 1997br, SN 1991T, and SN 1994D. Although SN 1997br is generally very similar to SN 1991T, it shows some interesting differences at various epoches. Spectra of SN 1997br seem to indicate an earlier transition to the dominant phase of Fe-peak elements after the B maximum. Si II lines in SN 1997br show a very short duration after the B maximum. We discuss the implications of our observations of SN 1997br for models of type Ia supernovae. Specifically, we suggest that some SNe Ia may result from decelerated detonations of white dwarfs., Comment: 25 pages, 17 figures, 4 tables, will be published the June,1999 issue of AJ
Published: 1999
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Publication Year Range

Publication Type

Database

Publisher

53 results on '"Qiu, Y.-L."'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources