Open AccessPulsar timing at Urumqi Astronomical Observatory: observing system and results
Author(s) -
Wang N.,
Manchester R.N.,
Zhang J.,
Wu X.J.,
Yusup A.,
Lyne A.G.,
Cheng K.S.,
Chen M.Z.
Publication year - 2001
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2001.04926.x
Subject(s) - pulsar , physics , glitch , crab pulsar , observatory , amplitude , astrophysics , astronomy , telescope , optics , detector
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.