VERA User’s Meeting
September 24, 25, 2014

The Tian Ma 65-m telescope inthe East Asia VLBI
N. Kawaguchi
Shanghai Observatory

Location of the TM65m
I am now working at Sheshan Campus.

The Sheshan Campus

Shanghai Observatory

Sheshan Campus

40 minutes fromthe down town

Geometry around Sheshan?

Sheshan
Down Town
25m

Sheshan

4km

65m
3km
SheshanCampus

6km
Don Jing
9km

East Asia VLBI Observation
on May 27, 2014

K-band Fringe Test
The Sheshan 25m telescope was participated with the KVN.

K-band fringes detectedin Sheshan CorrelatorSensitivities calculated from PCSnr
Stn Name (Stn index**) KVNUS(i) KVNYS(k) Sh25(j)DA193 isPCsnr (Observed)
70.2
69.2
28.7
referred as SEFD Observed (Jy)
1372
1392
3356
1.75JySEFD Expected (Jy)
1368
1450
2700
(60%)
(60%)
(50%)
(103K)* (114K)* (250K)

Stn Name (Stn index)
0528+134 is PCsnr (Observed)
referred as SEFD Observed (Jy)
2.01Jy, 80%
SEFD Expected (Jy)resolved

KVNUS(i) KVNYS(k) Sh25(j)
45.2
36.3
10.7
1242
1546
3360
1222
1328
2700
(60%)
(60%)
(50%)
(92K)*(100K)* (250K)

X-band Fringe Test
The 6-km baseline between Sh25m and Tm65m wasconnected with an optical fiber and possible to donear-real-time fringe detection.

KVN Ulsan

X-band fringes

Sensitivities in X-band analyzed on thePCA, Pseudo Closure Amplitude
StationKVNUS
Shanghai 25m
TianMa 65m
Shanghai 25m– TianMa 65m

CodePCASEFD (Jy)Prev. ResultUST

3.322x10-6
6.854x10-3
9.865x10-2

2.17x1061050
73----------

ST-------------

277

900
77273 (DA193)
254 (0518+134)

M81 with three CVN stations
Feb. 14, 2014

M81Urmqi

2.3 mas/ fringe@8GHz
The Sheshan-TianMa
Baseline is unique
for the shortbaseline and theconnection by an
optical fiber cable,
which is good for anear realtime fringe
detection and a PCA
analysis.

Sheshan 25mshanghai

Tian Ma 65m

Nanshan 25-m, Urmqi
25-m Radio telescope

X=228310.3726m
Y=4631922.7697m
Z=4367064.0425m
Under reforming to 26-m diameterM81 Observation on Sh25, Tm65, Ur25
Sh-Tm

Sh-UrUr-Tm

Pseudo Closure Analysis
and Sensitivity of Ur25m
14.5±0.9

𝑞 ∙ 𝑆 𝑀81 2𝐵𝑇 0.86 × 0.17 × 1.07 × 105
𝑆𝐸𝐹𝐷 𝑈𝑟 === 𝟏𝟎𝟕𝟖 ± 𝟕𝟎 [𝑱𝒚]𝑃𝐶𝐴 𝑆𝑁𝑅, 𝑈𝑟(14.5 ± 0.9)
( The SEFD(Sh) is 1050 Jy obtained in the EAVN fringe test in May, 2014)

Two point source model

Tau=0.08
Tsys Change=43-63K
Correlation 99.2% at
PA 75deg

MATLAB Solution

Jet Direction

PA=76±2 degree• We can give a twopoint-component
model to the changeof PCA with thecorrelation coefficientof 99% as seen in theprevious slide.
• We got peak PCA at
the position angle of75 degree.
• The Jet component islocated at almost
perpendicular to thegalactic plane.

Is the position angle changing withfrequency?
Our observation confirms this in X-band.

2.3GHz

8.6GHz

43GHz

22GHz?

Jet Precession?

22GHz ?
Our X-band Observationin 2014.12
From I. Martí-Vidal (2011)

Holography test on a 65-m main reflector

TOWARD 22GHZ

22-GHz test receiver set up
A test 22-GHz receiver only for the use in the holographic
surface measurement.
2.2V, 28mA

DC~ 16 GHz

SG22.2 GHz

To C-band receiver?

Frequency Response
A system gain of the LNA and the Mixer is 25.5 dB.
Input RF level: -41.5 dBm
LO level : +10.5 dBm
LO freq.: 16 GHz fixed

The highest frequency of the SG is limited to 22GHz

Test Staffs

Kawaguchi
Chen Ying-san (Left) and Liang Zhan Gang-san (Right)

Concluding Remarks• The Tian Ma 65-m telescope is a powerfultelescope which improves the sensitivity ofthe EAVN much more.
• The 65-m will soon be equipped with a 22GHz receiver which enables us to use in themajor frequency band of the VERA and KVN.
• The 65-m already has a 6-GHz receiver whichis quite effective to use in the Methanol
observations with JVN.

Sheshan Campus guide, Holography Test etc.

SUPPLEMENTS

Sheshan Campus
Main BuildingSheshan Campus
Research BuildingMy Office in Sheshan

Sheshan Campus
Dormitory

Sheshan Campus
Dining Hall

A water channel in the campus

65-m View from Campus

Electric Motor CycleSight Seeing around Sheshan
Classical houses sunk under water

SongJian City