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Astronomical Observatory

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Na Wang – One of the best experts on this subject based on the ideXlab platform.

  • the xinjiang Astronomical Observatory nsrt pulsar data archive
    Advances in Astronomy, 2019
    Co-Authors: Hailong Zhang, Na Wang, Markus Demleitner, Jie Wang, Jun Nie, Jianping Yuan

    Abstract:

    The sensitivity of our pulsar observation system with typical integration time of 16 minutes has reached 0.4 mJy after we have upgraded the receiver cooling system of NanShan 25-m radio telescope (NSRT) at Xinjiang Astronomical Observatory (XAO) in 2002. About 280 pulsars were observed after the upgrade. The NanShan station pulsar data is transmitted to the data center at XAO headquarters via a 300Mb/s dedicated data link for long-term storage, and the remote backup is realized by synchronous data transmission between NanShan station and XAO headquarters. Metadata extraction, archiving, and releasing are completed by the data release servers which are located in XAO headquarters. At present, more than 84000 pulsar observation data files in the PSRFITS format have been released with a maximum file size of 1GB. XAO pulsar data online service provides cone search and multiobject constraint query. We have published our data based on Virtual Observatory (VO) standards. The online pulsar data service is registered in the International Virtual Observatory Alliance’s Registry. Users can access the data through common VO tools.

  • Pulsar Timing at Urumqi Astronomical Observatory
    International Astronomical Union Colloquium, 2016
    Co-Authors: Na Wang, Xin-ji Wu, Jin Zhang, Richard N. Manchester, Aili Yusup, K. S. Cheng

    Abstract:

    AbstractA pulsar timing system has been set up using the 25-m Nanshan telescope of the Urumqi Astronomical Observatory. It uses a dual polarization receiver operating at 18 cm and a filterbank receiver. The data acquisition system is based on a PC using the Windows NT operating system. Timing properties of about 100 pulsars will be monitored with this system.

  • pulsar timing at urumqi Astronomical Observatory observing system and results
    Monthly Notices of the Royal Astronomical Society, 2001
    Co-Authors: Na Wang, K. S. Cheng, Jin Zhang, Richard N. Manchester, Aili Yusup, A. G. Lyne, M Z Chen

    Abstract:

    A pulsar timing system has been operating in the 18-cm band at the Urumqi Astronomical Observatory 25-m telescope since mid-1999. Frequency resolution allowing de-dispersion of the pulsar signals is provided by a filterbank/digitizer system. Observations of 74 pulsars over more than 12 months have resulted in updated pulsar periods and period derivatives, as well as improved positions. Comparison with previous measurements showed that the changes in period and period derivative tend to have the same sign and to be correlated in amplitude. A model based on unseen glitches gives a good explanation of the observed changes, suggesting that long-term fluctuations in period and period derivatives are dominated by glitches. In 2000 July, we detected a glitch of relative amplitude in the Crab pulsar. The post-glitch decay appears similar to other large Crab glitches.

M Z Chen – One of the best experts on this subject based on the ideXlab platform.

  • pulsar timing at urumqi Astronomical Observatory observing system and results
    Monthly Notices of the Royal Astronomical Society, 2001
    Co-Authors: Na Wang, K. S. Cheng, Jin Zhang, Richard N. Manchester, Aili Yusup, A. G. Lyne, M Z Chen

    Abstract:

    A pulsar timing system has been operating in the 18-cm band at the Urumqi Astronomical Observatory 25-m telescope since mid-1999. Frequency resolution allowing de-dispersion of the pulsar signals is provided by a filterbank/digitizer system. Observations of 74 pulsars over more than 12 months have resulted in updated pulsar periods and period derivatives, as well as improved positions. Comparison with previous measurements showed that the changes in period and period derivative tend to have the same sign and to be correlated in amplitude. A model based on unseen glitches gives a good explanation of the observed changes, suggesting that long-term fluctuations in period and period derivatives are dominated by glitches. In 2000 July, we detected a glitch of relative amplitude in the Crab pulsar. The post-glitch decay appears similar to other large Crab glitches.

G. Theureau – One of the best experts on this subject based on the ideXlab platform.

  • RFI mitigation in the context of pulsar coherent de-dispersion at the Nancay Radio Astronomical Observatory
    2009 17th European Signal Processing Conference, 2009
    Co-Authors: Ait D. Allal, R. Weber, I. Cognard, G. Desvignes, G. Theureau

    Abstract:

    Radio Astronomical pulsar observations require specific instrumentation and dedicated signal processing to cope with the dispersion caused by the interstellar medium. Moreover, the quality of observations can be limited by radio frequency interferences (RFI) generated by Telecommunications activity. This paper will present the innovative pulsar instrumentation based on Graphical Processing Units (GPU) which has been designed at the Nançay Radio Astronomical Observatory. In addition, first simulated results on RFI cyclostationary detectors, which will be implemented on the system, will be described and discussed.