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Chinese VLBA Programs and Chinese VLBI Network
2011.01.27
Xiaoyu HONG
Shanghai Astronomical
Observatory , CAS
(xhong@shao.ac.cn)
• SHAO : D. R. Jiang , Z. Q. Shen, A. Tao,
Y. Liu, X. Chen, Y. J. Chen, W. Zhao
B. Zhang, W. H. Wang, X. Hong et al.
• PMO: Y. Xu, et al.
• NJU: X. W. Zheng, et al.
• NAOC: H. Y. Zhang, C. J. Jin, R. D. Nan, B. Peng
et al.
• XJAO ( Urumq ) : X. Liu et al.
…
VLBA USERS in China
• Sgr* A
• Helical jet in AGNs
• Radio jet of AGNs with gamma ray emission
• Studies of red supergiant SiO masers
• et al.
A kinematic study of the compact jet in quasar B3 1633+382 Y. Liu, D. R. Jiang, Z.-Q. Shen & M. Karouzos 2010 A&A
FS QSO EGRET
source
z=1.814 OVV
14 epochs of VLBI observations of B3 1633+382 at 22 GHz with the VLBAtwo different possibilities of component classificationtwo corresponding kinematical models are adopted to explain the tracks of the three components. One is a linear motion, while another is a helical model.
VLBA Monitoring of 1633+382 during a Major Millimeter-Flare Y. Liu, T. P. Krichbaum, J. A. Zensus & D. R. Jiang in preparation
1633+382: OVV, z=1.814, core dominated gamma-ray bright AGN major mm flare 2001-2003.
3C345: QSO, z=0.593, well known for its helical motion.
1749+096: BL Lac, z=0.322, also very active QSO, and a very compact mm-source.
VLBA monitoring
22 & 37 GHz H.Teräsranta90, 150 & 230GHzH. Ungerechts
Color: Fractional PolarizationLeft contour: total intensityRight contour: linear intensity
Transverse Fractional Polarization (TFP): low in jet spine, high at edges
Interpretation in helical magnetic fields:TFP: low in spine, high at edges (Lyutikov et al. 2005);Signature of bifurcation of EVPA at low and top
Interpretation in magnetic compression and shear:Bottom and top EVPA: approximately parallel;Undetectable linear polarization in the middle (cancellation of emission from surface and deep magnetic)
Multiwaveband VLBA polarimetric observations of NRAO530Chen, Shen, Feng, 2010,MNRAS
3 VSOP images for high-z GPS
OQ172 z=3.522
Multifrequency VLBA Polarimetry of GPS Quasar OQ172 A High-z Laboratory for Studies of the Circumnuclear Environment Y. Liu, D. R. Jiang, L. Gurvits & A. B. Fletcher in preparation
High-z GPS (FFA/SSA)
the jet suffers a large band at ~ 3 mas
the most compact region in the 4 mas map was resolved into two components
extremely high rest-frame RM (RM>20,000 rad m-2) very steep RM gradient (at 7 mas, RM<100 rad m-2)Hβ FWHM 3,700 kms-1 3x108M⊙ [O III] FWHM 2,200 kms-1
What is the GPS absorption mechanism? (FFA or SSA)
Why is the jet strongly bent and curved, and how do physical properties vary along its length?
Which is the core?
What is the magnetic field topology? And why is the RM extremely high, and the inner jet depolarized?
0642+449 z=3.396
0201+113 z=3.639
multiband VLBA polarimetry observation
— VX Sgr ; 3-epoch VLBA data at 1999
1999 Apr. 24 1999 May. 23 1999 Apr. 31
Chen, Shen & Xu 2007, ChJAA
The estimated distance of 1.57± 0.27 kpc to VX Sgr from the “statistical parallax” analysis to proper motions of SiO masers.
Our observations provide the first direct evidence for an inward motion of SiO-maser shell around a red supergiant.
Chen, Shen, Imai & Kamohara 2006, ApJ
Φ=0.75-0.80
Vinfall=4.1 km/s
Proper motion
Studies of red supergiant SiO masers with the VLBA
— AH Sco; 2-epoch VLBA data Chen & Shen 2008, ApJ
2004 Mar. 8 2004 Mar. 20
Proper motion
Model fitting:
Studies of red supergiant SiO masers with the VLBA
Best-fit model for the SiO maser kinematics in AH Sco
V1=-14 km s-1 and α~0.5 support the presence of a real inward flow in the SiO maser region around AH Sco under the gravitation of the central star . The estimated distance d=2.26 kpc from the model fitting is in a good agreement with its near kinematic distance of about 2.0 kpc.
EPOCH 1 EPOCH 2
EPOCH 3 EPOCH 4 EPOCH 5
06,Jul
06,Dec
07,Aug
08,Feb
08,Aug
5 epochs VLBA Observations of SiO Masers around VX Sgr (Su et al. 2011, JAA, in press)
VX Sgr: v=1 J=1-0, v=2 J=1-0
4 epochs at 15, 43, and 86GHz
Helical jet structure driven by K-H instability : multiple jet bendings in 1156+295 on pc--kpc scales, derived from VLBA observations
Knotty radio jet of 3C48 revealed by the VLBA – indicative of jet-NIR clouds interactions – good case for studying AGN evolution and feedback
Nucleus
Hot spot
Wilkinson et al. 1984; Feng et al. 2004; Worrall et al. 2005; An et al. 2010
Major Facilities for RA in China
Delingha 13.7m
21CMA
L,C,S/X,K L,C,S/X,K
S/X S/X
L,C(5/6G),S/X,K L,C(5/6G),S/X,K
S/X S/X
L,C,S/X:2012Ku,K,Ka:Q:2015 L,C,S/X:2012Ku,K,Ka:Q:2015
L,C:2012K :?L,C:2012K :?
Black:recent status Yellow:plan Yellow:plan L,C,X:2014 L,C,X:2014
VLBI in China
CVN --VLBI data processing center
Hardware correlator (5 stations)Software correlator (10 stations) Output data: CE-1 format FITS format Software for CE-1 data processing (near real time eVLBI, in 5 min.)
Digital BBC for 4 stations
• 4 Processing Boards• One for data Selecting• 4 Ifs input, 2GHz total
BW• 16 Ch output / VSI-H• 2 VSI-H interface• 1 / 2 / 4 bit output
• Dual redundant system
1 )、 VLBI 测站
2 )、数据传输网络2 )、数据传输网络
3 )、 VLBI 中心
Beijing centerBeijing center
VLBI centerVLBI center
Network 34 MbpsNetwork 34 Mbps
stationsstations
USB dataUSB data
VLBI data in 5 mVLBI data in 5 m
SHSHBJBJKMKMURUR
How VLBI work together with USB?
VLBI tracking for Chinese Lunar Project
• VLBI plays important role for Chinese Lunar project.
• VLBI is famous to people in China this moment.
2007.12 for CE-1
2010.12 for CE-2
e-VLBI2007 August 28: Shanghai –Australia & Europe (256Mbps) 2008 June 17: Shanghai –Australia & Japan (512Mbps)2009 January 6: Shanghai-Urumqi (256Mbps)2009 January 15-16: IYA marathon obs. (Asia, Australia, Europe, America)2009 February - : Shanghai 25-m participates in the routine eEVN sessions
23
CVN (Km+My+Sh+Ur) + Onsala 20-m + Medicina 32-m;
2009 Aug 5-6;24 hr;X-band;5 GPS sources
JIVE Correlator
0129+560
CVN
(An et al. 2010, in prep)24
Shanghai 65m Radio Telescope
• 65-m in diameter fully steerable radio telescope
• Active surface system
• Cover 1.4 – 46 GHz with 8 bands :– L(1.6GHz)– S/X(2.3/8.4GHz)– C(5GHz)– Ku(15GHz)– K(22GHz)– Ka(30GHz) – Q(43GHz)
• General-purpose (radio astronomy, geodynamics, single-dish, VLBI,
• VLBI tracking for Chinese Lunar projects ) 25
• 2008 : funded, contract to CETC54 for the antenna construction
• 2009: complete design, start manufacturing
• 2010: ground breaking, foundation completed
• 2011: antenna completed
• 2012: L/S/C/X band test observations, ready for participation in the Chinese Lunar Mission
• 2013-14: active surface tested,
Ku/K/Ka/Q band test observations
• 2015: project accomplished, in full operation
Project Timeline
26
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