Recent Observational Results and Activities with...
Transcript of Recent Observational Results and Activities with...
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Recent Observational Results and
Activities with KVN
Do-Young Byun (KASI)
Survey Science Group Workshop 2016
@ High1
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KVN Yonsei
KVN Tamna
KVN Ulsan
Frequency(GHz)
Beam Size(mas)
SEFD(Jy)
5σ Detection (mJy) @ t_int (s)
ΔI (mJy/beam)@ 8h integration
21.25-23.25 6 ~1300 60 @120s 0.2
42.11-44.11 3 ~1900 90 @ 60s 0.3
85-95 1.5 ~3200 270 @ 30s 0.6
125-142 1 ~6000 570 @ 20s 1.0
- Simultaneous 4 Frequency- Dual Pol. 2 Frequency
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Very Long Baseline Interferometer
• High spatial resolution
• Very Compact & Bright Objects
φOBS() = φTRO + φGEO + φINSTR + φION + φSOURCE
Correlator Outputor
(Complex Visibility)
ImageFFT
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φOBS = φTRO + φGEO + φINSTR + φION + φSOURCE
FAST SLOW
- RφOBS = R(φTRO + φGEO + φINSTR + φION + φSOURCE ) where R = HIGH / LOW
Target Source
From Rioja @ EVN Symposium 2015
FPT : Frequency Phase TransferφTRO - (HIGH / LOW) φTRO = 0 Weak Source Detection
> ~10 min
CT
time
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SFPR
SFPR : (Calibrator) Source + FPTφGEO + φINSTR + φION -> 0 Multifrequency Astrometry
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KVN SFPR Demonstration using Polar Cap samples(Rioja et al. AJ 2015)
1842+682
1807+698
2007+777
1928+738
1803+784
2o
4.5o
6.7o
6.3o
11o
3.6o
8.6o
Triangle 1Triangle 2
22,44,88,132 GHz
KVN Obs.:Duration 8 hours3 min scan/source
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Frequency Phase Transfer22 GHz, raw
44 GHz, raw88 GHz, raw
132 GHz, raw
2244, x22288, x4
22132, x6
From Rioja 2015
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Frequency Dependent Position Shift
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Dust layer
SiO maserJ=1-0, J=2-1, J=3-2v=1, v=2, v=3
H2O maser
Mass-loss
Shock propagation
15 Late-type stars (from AGB to PPN) ; Se-Hyung Cho +• Stellar pulsation shock wave mass-loss• Physical Properties and Dynamical Variation of inner and outer
region• Mass Loss, Asymmetric (Bipolar) Structure
KSP : KVN 4 band monitoring of Evolved Stars
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Mira variable star V1111 Oph
(Obs. : 2014 Oct. 28)
Superposed maps of H2O 616 – 523 (22 GHz) and
SiO v=1 J=1-0 (43 GHz), v=2 J=1-0 (42 GHz) masers (YJ Yun et al. in Prep)
Supergiant star VX Sgr
(2014 Nov. 27)
Superposed maps of H2O 616 – 523 (22 GHz)
and SiO v=1 J=1-0 (43 GHz), v=2 J=1-0 (42
GHz) masers (DH Yoon et al. in Prep)
Astrometric Registration of H2O and SiO Masers
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Cho et al. in Prep
First 4 Band SFPR Map toward VY CMa
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KSP: iMOGABA(Interferometric MOnitoring of GAmma-ray Bright AGN)
• PI: Sang-Sung Lee
• Origin of gamma-ray flares in AGN
• Monthly VLBI monitoring of ~30 AGN with 4 frequency bands
• Complementary to VLBA monitoring at 15 & 43GHz ( MOJAVE , BU)
22GHz 43GHz 86GHz 129GHz
2013-Nov-20
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129GHz Images using FPT
• FPT Results of iMOGABA ( Algaba+ JKAS 2015 )• Successful Image for 8 among 12 failed sources
CLEAN map @ 129 GHzPeak= 284 mJy/beamrms= ~ 1 mJy/beam
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Polarizations w/ KVN SD & CSO
• RM at shorter wavelengths is larger in relativistic radio jet with a wavelength dependence of 𝑅𝑀 ∝ λ−2.2
the Faraday rotation originates in or in close proximity of the jet.
Lee et al. 2015 ApJL3C279CSO (350m) KVN (3.5, 7, 14mm) YS & US
𝑅𝑀22−43 = −647 𝑟𝑎𝑑 𝑚−2
𝑅𝑀43−86 = −2713 𝑟𝑎𝑑 𝑚−2
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444 KVNCS2 sources + 858 known calibrators at K band (2015~2019?)
KVN Legacy Program (Taehyun Jung)
credit: J. A. Lee
Total: 1302 sources
Multifrequency AGN Survey with KVNFinding more high-frequency sources & Maximizing the KVN uniqueness
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Wide Band Operation- First 4 x 2Gbps(512MHz) Fringe
22GHz RHCP 43GHz RHCP
22GHz LHCP 43GHz LHCP
Yonsei-Ulsan- 2015 June
4 x 2 Gbps : 8Gbps- 8 times wider BW- ~3 times higher SNR
New VLBI Recorder- Mark6- 16Gbps max
512MHz BW
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VLBI Collaboration
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KaVA (KVN and VERA Array)
• Large Programs (2016~)– Intensive Monitoring of M87 and SgrA*
– Extended Study of Stellar Masers
– High Mass Star Formation Study using Water and Methanol Masers
- 22 & 43GHz- Excellent Imaging Capability- Joint Operation ~1000h /yr
Niinuma+ 2015
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Sejong 22m
KVN@43G
P: 8.01Jy/bm
rms: 0.04 Jy/bm
KVN+SJ@43G
P: 7.73Jy/bm
rms:0.02 Jy/bm
YS US TN SJ
YS - 305 477 120
US 305 - 358 206
TN 477 305 - 367
SJ 120 206 367 -
Baselines between KVN-Sejong
2 / 8GHz Rx22 / 43GHz Rx
Sejong Geodetic VLBI Station
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Frequency Dependent Position Shift
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Global Extended – KVN
ATCA 22m x 6 (22/43/86)
VLBA MK 25m(22/43/86)
VERA20m x
2 (22/43)
KVN 21m x 3 (22/43/86/129)
Tianma65m (22/43)
Sardinia 64m(22/43/86)
Yebes 40m(22/43/86)
Jung et al. 2015 33Credit : Richard Dodson
Xinjiang26m (22/43)
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Summary
• SFPR technique are successfully applied to both continuum and maser sources upto 130GHz– First 4 bands registered image (VY-CMa)
– AGN Core Position Shift
• KVN KSP and KaVA Large Programs were launched.
• Collaboration for Multi-Frequency mm-VLBI – VERA Miz & Iriki, Yebes 40m, Sejong 22m
– ATCA sub array
– VERA Oga & Ishi, Tianma 65m, SRT 64m, Effelsberg 100m, Onsala 26m