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!