Korean VLBI Network (KVN)
KVN and VERA Array (KaVA)
andExtended-KVN (E-KVN)

Taehyun Jung & Do-Young Byun (KASI)
On behalf of KVN and KaVA Operation TEAM
2018 September 26 @ VERA UM, Miataka, Japan

Korean VLBI Network (KVN)
Yonsei• 3 Telescopes (D = 21m)
• 22/43/86/129GHz• Baseline 300 - 500 km

Ulsan•  = 1 - 6 mas• Science Targets
AGN/SF/Evolved Star+ microquasar

θHBPW ~ 6 mas @ 22 GHz~ 1 mas @ 129 GHz

Tamna

16th VERA User’s Meeting 2018 @ Mitaka, Sept. 25~26, Japan2Multi-Frequency Receiving System• Simultaneous Multi-frequency Observation• @ 22/43/86/129GHz• Dual Pol : LCP & RCP• (Source) Frequency Phase Transfer• Weak Source Detection• Chromatic Astrometry• Multi-Frequency Observation• Efficient (Obs, Cal + Sci)
• SED & Rotation Measure

16th VERA User’s Meeting 2018 @ Mitaka, Sept. 25~26, Japan

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MASK: Multi-Frequency AGN Survey with KVN

KVN Multi-FrequencyObservations•Largest number of New detections Ever! (on-going)• ~300 AGNs(>70%) @ 86GHz~250 AGNs(>50%) @ 130GHz• ~80 high-z AGNs (z = 2.5-6.5)•M/F Images/Astrometry• Evolved Stars & AGNs•

Multi-Frequency Polarimetry• AGN jet structure and magnetic fields
from M/F Rotation Measure•

Demonstration on the performance ofsimultaneous M/F• Tropospheric / Ionospheric phase calibration• New standard of mm-VLBI

MASK Team in prep

M/F maser maps of Vx Sgr

D.H. Yun et al. 2017

M/F VLBI Polarimetry

J.-H. Park et al. 2018

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KVN Operation & Publications• VLBI ~ 4000h/yr (+ SD 500-1000 h/yr/site)• KVN Only : 2500h• KaVA (KVN and VERA Array) : 1000h• EAVN/EVN/GMVA/Sejong > 300h(>600 in 2018A)KVN Operation (2014-2018A)• KVN Key Science Projects : 1000h/yr• KaVA Large Programs : 500h/yr• Global Common Use : 1000h/yr• KVN : 500h/yr + KaVA : 500h/yr• Total 101 refereed papers since 2013
• SCI 78 (SD & VLBI)• ~20 papers in 2018
• https://radio.kasi.re.kr/kvn/publication.php

16th VERA User’s Meeting 2018 @ Mitaka, Sept. 25~26, Japan5

KVN System Updates• Precise Reference Position (IVP) of KVN Ulsan & Tamna Telescope- Astrometry & Geodesy- Reference Frames and Fundamental Physics- Applications for geophysics and space navigation (VLBI tracking)Axis offset (mm) :

0. 86

2.43

Yoo et al. (submitted)

16th VERA User’s Meeting 2018 @ Mitaka, Sept. 25~26, Japan

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KVN System Updates (in progress)

OCTAD Test

1GHz BW @ 22GHzKVN 4-Frequency Full Polarization
KDAS (4Ch)+ OCTAD (4Ch)+ 2xMark6

16Gbps (512MHz x 8 Channel)
22L/R, 43L/R, 86L/R, 129L/R
16th VERA User’s Meeting 2018 @ Mitaka, Sept. 25~26, Japan

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KVN System Updates• Receiver Upgrade to support wide frequency range• K-band: 21.25 - 23.25 GHz —> 18 - 26 GHz (all KVN)
- compact feed horn, Wideband compact polarizer, New LNA, Trx~25K• W-band: 85 - 95 GHz —> 85 - 116 GHz (KUS) (KYS/KTN 2019B~)• Q-band: 42.1- 44.1 GHz —> 35 - 50 GHz (2019B~)
First Light with upgraded 22GHz Rx
Trx ~ 25K

KUS 2018.7

NH3 Line at 23.7GHz

KTN 2018.7

16th VERA User’s Meeting 2018 @ Mitaka, Sept. 25~26, Japan8

KaVA : KVN and VERA Array• 7 Telescopes (D ~ 20m)
• Baseline : 300 - 2300 km• Frequency : 22/43(/86/129)GHz• Beam Size : 1.2/0.6(/1.5/1.0) mas• Baseline Sensitivity ~ 10/20 mJy

Daejeon Correlator@KJCC
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Operation Time of KaVA
700
600
500
400300200

EAVN
Large Program
Common Use
DT (System Eval + ToO)
Science W/G

1000• Steady operation of ~ 500 hours in a season since 2015B• Start 2nd phase of KaVA Large Programs since 2018A• EAVN Observations ~ 120h in 2017A and 170h in 2018A

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Large Programs
ESTEMA

15B

16A

16B

17ATotal

12680

5242300411

AGN-1686060+123(EAVN)

SFR-70108

23201

Total

126

318

220248912• 1st phase of KaVA LPs were finished in 2017A• 2nd phase of KaVA PLs were resumed in 2018A• Imaging Survey —> Intensive Monitoring / (Astrometry)11

2nd phase of KaVA Large Programs• ~170h / program /yr• Evolved Star• EAVN Synthesis of Stellar Masers Animations (ESTEMA)• P.I.: S.-H. Cho (KASI), Hiroshi Imai (Kagoshima Unv.)• AGN• Exploring the vicinity of supermassive blackhole with KaVA
• P.I. : Motoki Kino, B. W. Sohn (KASI)• Star Formation• Understanding high-mass star formation through KaVAobservations of water and methanol masers• P.I. : Tomoya Hirota (NAOJ), K.-T. Kim (KASI)
12KaVA/EAVN Common Use CfP• 250h / semester• share 100h for EAVN from 2018B• 2018B: First Year of EAVN CfP announcement• 6 for EAVN + 8 for KaVA
1514131211109876543210

Submtted
Accepted

2014A

2014B

2015A

2015B

2016A

2016B

2017A

2017B

2018A

13KaVA Upgrade Activities• New Modes from 2018A• C2 (2 IFs x 128MHz BW)• Wide-Field Imaging (Q-band only)• Under the test
• Phase referencing for high precision astrometry• K/Q Simultaneous Observations• 2Gbps mode
• Polarization
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Notice to KVN & KaVA Users• KVN and KaVA(+EAVN) Common Use• ~ 500h/yr for each KVN and KaVA(+EAVN)• Proposal Deadline and operation period• Nov 1 for A semester ( Jan 16 - June 15 )• June 1 for B semester ( Aug 15 - Jan 15 )• Homepage• KVN: http://kvn.kasi.re.kr• KaVA: http://kava.kasi.re.kr• EAVN: http://eavn.kasi.re.kr• Web administrator: Jae-Sik Shin• max observation period of 1-year per project• max 100h / proposal• Scheduling

KVN and VERA• KaVA: 5-day sessions with 2-week interval• KVN: scheduled inbetween KaVA sessions• Obs schedule file (.vex) submission: one week in advance• New KaVA/EAVN scheduler: Kiyoaki Wajima• User Support• KVN: Chungsik Oh (kvnhelp@kasi.re.kr)• KaVA: Tomoya Hirota & Chungsik Oh (kavahelp@kasi.re.kr)
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KVN Archive Database(in progress)
Developer: Jae Sik Shin

• Maximize scientific productivity• Provide public information• Open science policy••••••KVN observation database since 2013
All types of KVN observations (incl. normal, systemtest)
Various options for data search(src/date/freq/position)
Download link (2019~)
Calibrated (pipeline processed) data (after 2019mid)
Extended to KaVA/EAVN

Extended-KVN• 2002 IVS Proceedings (Minh)• 4 in South + 2 in North

Current Limitations•

Limitation of 3-station KVN # of stations• Poor UV-coverage# of baselines• No amplitude self-cal# of phase closure# of amp. closure• Lower success rates
at high frequencies (86/129GHz)

3456361015

121020

N/A

1515

Amplitude self-cal using VLBA 6 stations•

In proportional to # of baselines

beforeafter

Accuracy of VLBI observables(delay, rate, amplitude)• Image fidelity / dynamic range• Imaging speed•

6 times better dynamic range 18

UV simulation for site selection• UV-coverage & beam pattern• baselines ~ 50 - 500 km• high success rates• candidates : Pyeonchang + Sokcho( + Kwangju )SokchoPyeonchang

Kwangju

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KaVA+Yebes (Spain)
Simul. Dual-Freq. VLBI Obs. Campaign

Global Collaborations on
Simultaneous Multi-Frequency VLBIVERA, NRO45m, Yebes 40m, ATCA, Mopra 22m, Tianma 65m, Thai 40m,
Effelsburg 100m, Millimetron (22/43/86/230GHz), QTT(110m?)• Compact Triple-band Receiver : Italy (Sd64m, Nt32m, Md32m),Finland(Mv14m)•Millimetron우주공간 VLBI를 위한 러시아 위성과 협력

ngVLA

Jung+2015

Thank Yo

VERA MIZUSAWA

GLTEAVNCVN TIANMA