IPS Observations in China:Past, Now and Future
Lijia Liu
National Astronomical Observatories, Chinese Academy of Sciences (NAOC)
(Given by Mario M. Bisi, STFC RAL Space)
Outline
1. IPS study in China
2.Future development of IPS in China
IPS study in China
China began IPS study in the1990s
• IPS theory study: Y. H. Qiu, X. Z. Zhang, P. Z. Ye et al.
• IPS observation: NAOC (BAO)
IPS with MSRT
• Since 1990s• 9m, 28 telescopes• Frequency: 232MHz• Additive mode• Equivalent aperture
47m
X. Z. Zhang et al., Chinese Science bulletin Vol. 6, 2001
MSRT : Miyun Synthesis Radio Telescope
IPS with MSRT
X. Z. Zhang et al., Chinese Science bulletin Vol. 6, 2001
X. Z. Zhang et al., Chinese Science bulletin Vol. 6, 2001
2000-4-12 3C48 raw data (a) and power spectrum (b)
Raw data Power spectrum
IPS with MSRT
The Retirement of MSRT
• The degradation of radio environment in Miyun Station
• The construction of a new radio telescope
MSRT was retired early this century IPS observation was ceased for several years
IPS with 25 m in Urumqi
• First SSSF IPS observing station in China
• Diameter : 25m
• Wavelength: 18cm
• Sampling interval: 0.25ms
• Integration interval: 10ms
IPS with 25 m in Urumqi
Key Parameters of IPS Observations with the 25m Radio Telescope Performed in 2008 at UAO
L. J. Liu et al,,RAA,2010,10,6,577-586
IPS with 25 m in Urumqi
Characteristic spectrum of the 18 cm receiver at UAO before and after filtering.
L. J. Liu et al,,RAA,2010,10,6,577-586
Flow chart for data processing
Flow chart for data acquisition
IPS with 25 m in Urumqi
Date: 2008.12.1
Parameters : AR=1.2 , α=3.1 , V=400km/s
Fitting spectrum
3C3457.1Jy0.23AU
L. J. Liu et al,,RAA,2010,10,6,577-586
IPS with 25 m in Urumqi
IPS with 50m in Miyun
• Observing frequencies(MHz)
UHF( 327/611)
S/X(2300 , 8400)
• The only SSDF IPS observing station in China• Serving the Chinese Meridian Project
Technical Data of the Telescope
X. Y. Zhu et al, RAA,2012,12,8, 857-864
IPS with 50m in Miyun
IPS with 50m in Miyun
Front-end of IPS observation system.
X. Y. Zhu et al, RAA,2012,12,8, 857-864
Data acquisition system
IPS with 50m in Miyun
IPS with 50m in Miyun
(a):IPS spectrum of observation data from 3c237b on September 27, 2011 ( Red line is the theoretical fitting curve).(b)Normalized Co-spectrum(NCS) between the pairs of radio frequencies 2300/8400 in MHz.Scales are logarithmic for frequency and power density (2dB per division) and linear for NCS.
X. Y. Zhu et al, RAA,2012,12,8, 857-864
1. IPS study in China
2.Future development of IPS in China
Future development of IPS in China
• 25 m in XAOThe most efficient radio telescope in China,
hard to apply
• 50m in Miyun Under take the Lunar Project at the
meantime, IPS observation can only be a part time job
Future development of IPS in ChinaIPS group in JLRAT, NAOC
Future development of IPS in China
• Build special IPS telescope• Research new low frequency
receivers• Development of digital back-end• Perfecting data processing method• Strengthening international
cooperation
Thank you!