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

Transcript of Recent Observational Results and Activities with...

  • Recent Observational Results and

    Activities with KVN

    Do-Young Byun (KASI)

    Survey Science Group Workshop 2016

    @ High1

  • 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

  • Very Long Baseline Interferometer

    • High spatial resolution

    • Very Compact & Bright Objects

    φOBS() = φTRO + φGEO + φINSTR + φION + φSOURCE

    Correlator Outputor

    (Complex Visibility)

    ImageFFT

  • 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

    ________________________

    ________________________

    SFPR

    SFPR : (Calibrator) Source + FPTφGEO + φINSTR + φION -> 0 Multifrequency Astrometry

  • 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

  • Frequency Phase Transfer22 GHz, raw

    44 GHz, raw88 GHz, raw

    132 GHz, raw

    2244, x22288, x4

    22132, x6

    From Rioja 2015

  • Frequency Dependent Position Shift

  • 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

  • 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

  • Cho et al. in Prep

    First 4 Band SFPR Map toward VY CMa

  • 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

  • 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

  • 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

  • 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

  • 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

  • VLBI Collaboration

  • 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

  • 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

  • Frequency Dependent Position Shift

  • 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)

  • 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