Recent Observational Results and Activities with KVNhome.kias.re.kr/MKG/upload/2016SSG/05_dybyun.pdfSummary • SFPR technique are successfully applied to both continuum and maser

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