multi-frequency agn survey with kvn - ホーム | 国立天 … ae lee, ilje cho, dawoon jeong,...

MASK TEAM: Taehyun Jung, Do-Young Byun, Bong Won Sohn, Minsun Kim, Guangyao Zhao, Jan Wagner, Kiyoaki Wajima, Cristian Saez de Cea, Woojin Kwon, Jeong Ae Lee, Ilje Cho, Dawoon Jeong, Dongsoo Ryu, Jongsoo Kim

Multi-frequency AGN Survey with KVN Finding more high-frequency sources & Maximizing the KVN uniqueness

Challenges of AGN Jets, 20 Jan. 2017 @ NAOJ, Mitaka, Tokyo

KVN Legacy Program (planned)

Intro

Radio Surveys

Radio Sources Interferometer

http://skyview.gsfc.nasa.gov/images/high_res_radio.jpg

FIRST NVSS SUMSS WENSS

Frequency 1400 MHz 1400 MHz 843 MHz 325 MHz

Area (deg2) 10,000 33,700 8,000 10,100

Resolution 5” 45” 43” 54”

Detection limit 1 mJy 2.5 mJy 3.5 mJy 15 mJy

Coverage δ > +22° δ > -40° δ > -30° δ > +30°

Sources/deg2 90 60 50 20

# of Sources 946,432 1,773,484 211,050 229,420

References Becker+1995 Condon+1998 Bock+1998 Rengelink+1997

WENSS: Westerbork Northern Sky Survey

FIRST: VLA Faint Images of the Radio Sky at Twenty Centimeters Survey

NVSS: NRAO VLA Sky Survey (NVSS)

SUMSS: Sydney University Molonglo Sky Survey

> 3400 sources are available

Radio Sources VLBI

Radio Fundamental Catalog of Compact Radio Sources (L. Petrov)

11,448 (up to date)

http://astrogeo.org

Num

ber

of Sourc

es

Time (year)

Name Wavelength # of Sources Reference

CJF survey 18 & 6 cm 293 Pollack et al. 2003

ICRF/RDV 13 & 3.6 cm ~ 500 Ojha et al. 2004

VLBA Calibrator Survey 13 & 3.6 cm > 3400 Kovalev et al. 2007

VSOP VLBApls 6 cm 374 Fomalont et al. 2000

VSOP Survey 6 cm ~ 300 Dodson et al. 2008

VIPS 6 cm 1127 Helmboldt et al. 2007

2cm Survey 2 cm 250 Kovalev et al. 2005

MOJAVE 2 cm > 133 Lister & Homan 2005

VERA FSS / GaPS 1.35 cm 500 Petrov et al. 2007

ICRF 22 & 43 GHz 1.37 & 0.7 cm ~100 Lanyi et al. 2010

GMVA 3mm 3 mm 123 Lee et al. 2008

TANAMI 3.5 & 1.3 cm 80 Ojha et al. 2010

KVN Q-CAL survey 7 mm 638 Petrov et al. 2012

KVN W/D-CAL survey 3.5 & 2.3 mm > 500 (W) Lee et al. (In prep.)

KVN K-CAL survey 1.3 cm > 400 (K) Lee et al. (in prep.)

VLBI Surveys

Untill now...

• Number of sources at mm-wavelengths are still very limited - more than ~3400 sources are available at 3.6 cm,

while ~160 sources are available shorter than 3 mm (Dhanya+ in prep)

3414 sources at 3.6 cm (Beasely 2002) 109 sources at 3 mm (Lee+ 2008) 164 sources at 3 mm (Dhanya+ in prep)

mm-VLBI study of AGN

• High-frequency VLBI (mm-VLBI) observations are required to understand of the physical processes at the innermost region in AGN and in the vicinity of suppermassive black holes - much less affected by the source intrinsic opacity effects

• Determination of the phyiscal parameters of the innermost & most compact component (e.g. the jet base) - constraints for current jet and shock models (Blandford & Königl 1979, Königl 1981, Marscher & Gear 1985 etc)

- multi-band spectra & VLBI structures

• mm-VLBI observations have been successfully conducted at different frequencies (43/86/129/230GHz) with the available VLBI network (VLBA, GMVA, HAS, EHT)

• However, above 86GHz are still demanding and general properties of the millimeter VLBI sky are not very well known

• mm-VLBI observations (> 20 GHz, <15 mm) are very difficult - atmospheric coherence time < 1 min - antenna efficiency is less efficient - receivers are less sensitive - sources are weaker than cm wavelengths - tropospheric water vapour absorption

mm-VLBI observations

Difficulties in mm-VLBI

• Sensitivity (Image)

ΔIm=SEFD/[ηs⋅(N⋅(N−1)⋅Δν⋅tint)1/2] Jy/beam

• Radio telescope performance - Surface accuracy, High Tsys, Rx performance …

• Radio Emission

• Non-thermal • 15~20% of AGNs are radio-loud

others are mostly radio-quiet

Coherence Function

Coherence Time

Coherence

*Typical value of atmospheric phase stability ~ 10-13

VLBI Sensitivity

(A. Roy) Pico Veleta – Onsala baseline Source : BL Lac Frequency : 86 GHz

Errors coming from the ATMOSPHERE are still remain the most serious difficulty which significantly degrade the sensitivity and imaging capability of mm and sub-mm VLBI observation

Korean VLBI Network

Simultaneous Multi-Frequency VLBI System

KVN Yonsei Observatory

KVN Tamna Observatory

KVN Ulsan Observatory

22GHz

43GHz

86GHz

129GHz

Beams from antenna

Multi-Frequency

Receiving System

4Ch Receiver @ Yonsei

Han et al. (2008)

Band K Q W D

Freq. Range 21.25-23.25 42.11-44.11 85-95 125-142

Trx (K) 30-40 70-80

(40-50 KUS) 80-100 50-80

Full Polarization

2 ( )

2 ( )

h h h h

str g C inst trop ion LO

l l l l

str g C inst trop ion LO

h lr /h lr

2 2

0

2 22 ( ) 2 1 ( )

h h

l l

str g g ion LO LOhh l h h h l h l

l h

Self-calibration at lower frequency

l

str 2 ( )l l

g C inst trop ion LO

By doing Self-calibration again for longer solution interval, we can get an image at higher frequency

Core-shift

diff in maser lines

slow varying term

ionosphere instrument Source

Structure

Frequency Phase Transfer (FPT)

FPT applied using K-band solint 0.3

24 hours

43GHz

NRAO150 0133+476 3C84 1308+326 3C279 3C345 NRAO530 SGR-A 3C454.3 2255-282

0202+149 1023+131 3C273 1633+382 NRAO512 FAS 1921-293 BLLAC NRAO150

FPT applied using Q-band solint 0.1

129GHz

86GHz

NRAO150 0133+476 3C84 1308+326 3C279 3C345 NRAO530 SGR-A 3C454.3 2255-282

0202+149 1023+131 3C273 1633+382 NRAO512 FAS 1921-293 BLLAC NRAO150

FPT applied suing K-band solint 0.3

24 hours

High frequency VLBI Phase Calibration by Lower Frequency Phase Solutions

Fringe Solution SNRs at 22GHz (solint 0.3)

Power of Simultaneous

Multi-Frequency Receiving System

30min

22 GHz

43 GHz

86 GHz

129 GHz

Ceff 22GHz 43GHz 86GHz 129GHz

22 GHz - 0.97 0.91 0.88

43 GHz 0.97 - 0.97 0.96

86 GHz 0.91 0.97 - 0.99

129GHz 0.88 0.96 0.99 -

SNR~213 (~90% of theoretical SNR)

𝜙 ℎ𝑖𝑔ℎ

∝𝜈ℎ𝜈𝑙𝜙𝑙𝑜𝑤

non-dispersive characteristic of troposphere

Power of Simultaneous

Multi-Frequency Receiving System

30min

22 GHz

43 GHz

86 GHz

129 GHz

Ceff 22GHz 43GHz 86GHz 129GHz

22 GHz - 0.97 0.91 0.88

43 GHz 0.97 - 0.97 0.96

86 GHz 0.91 0.97 - 0.99

129GHz 0.88 0.96 0.99 -

SNR~213 (~90% of theoretical SNR)

𝜙 ℎ𝑖𝑔ℎ

∝𝜈ℎ𝜈𝑙𝜙𝑙𝑜𝑤

non-dispersive characteristic of troposphere

Using the KVN, more than 30min integration is achievable even at 130 GHz!! while only ~12 sec integration is a nomial integration time at 130 GHz

KVN Sensitivity by FPT

Frequency Band 22 GHz 43 GHz 86 GHz 129 GHz

Bandwidth (MHz) 64 (Total 256MHz ~ 1Gbps)

System temperature (K) 100 150 200 250

SEFD (Jy) 1329 1993 4229 4983

Integration time (sec) 20 1800 (30 min)

Sensitivity (mJy) 29.8 4.7 10.5 11.8

5σ Sensitivity (mJy) 149.2 23.6 52.4 60.0

※ Aperture efficiency : K ~ 0.6, Q ~ 0.6, W ~ 0.45, D ~ 0.4


Bandwidth (MHz) 512 MHz for each band


SEFD (Jy) 1329 1993 4229 4983


Sensitivity (mJy) 10.5 1.7 3.7 5.0


1Gbps Multi-Freq. Obs Mode



21.7GHz Peak ~ 26.4 Jy/beam Beam 8.5 x 3.5 mas -78.8°



130 GHz Peak ~ 5.0 Jy/beam Beam 1.09 x 0.58 mas -81.4°

First KVN’s 4-Frequency Simultaneous Observation VLBI Images Source: 3C279 43/86/130GHz visibility phases are calibrated by 22GHz’s

Phase reference

Example: J0502+1338

43 GHz

86 GHz 129 GHz

KVN single dish flux at 22GHz ~ 0.3 Jy (No SD detection at 43GHz)

KT-KU 22 GHz

KT-KY

KU-KY

Corr

ela

ted A

mplitu

de (m

Jy)

UV distance (Mega wavelength)

43 GHz

86 GHz 129 GHz

22 GHz

43 GHz

86 GHz 129 GHz

22 GHz

Example: J0502+1338

43 GHz

86 GHz 129 GHz

KVN single dish flux at 22GHz ~ 0.3 Jy (no detection at 43GHz)

KT-KU 22 GHz

KT-KY

KU-KY

Am

plitu

de (m

Jy)

UV distance (Mega wavelength) Credit: B. W. Sohn

2016

KVN Sensitivity by FPT


Bandwidth (MHz) 64 (Total 256MHz ~ 1Gbps)


SEFD (Jy) 1329 1993 4229 4983


Sensitivity (mJy) 29.8 4.7 10.5 11.8


※ Aperture efficiency : K ~ 0.6, Q ~ 0.6, W ~ 0.45, D ~ 0.4


Bandwidth (MHz) 512 MHz for each band


SEFD (Jy) 1329 1993 4229 4983


Sensitivity (mJy) 10.5 1.7 3.7 5.0





Overcome the difficulties in the atmosphere

Number of VLBI sources at mm-wavelengths are still very limited - more than ~3400 sources are available at 3.6 cm,

while ~120 sources are available shorter than 3 mm

> 3400 sources at 3.6 cm (Beasely 2002) ~120 sources at 3 mm (Lee+ 2008)

Uniqueness: Simultaneous Multi-frequency mm-VLBI observation of AGNs

• Most of AGNs are variable on time scales • Simultaneous observations at multi-frequencies can provide important

clues on physical conditions, especially in particular compact systems

• Sample: 1533 sources Known K-band VLBI sources 837 + KVN K-band fringe survey 426 (※ 43 common sources)

Samples based on KVNCS J. A. Lee (submitted)

Goal: Constructing Multi-Frequency VLBI Catalog of AGNs Utilizing KVN’s uniqueness & playing a leading role in mm-VLBI

Multi-frequency AGN Survey with KVN

Number of VLBI sources at mm-wavelengths are very limited

3414 sources at 3.6 cm (Beasely+2002) 109 sources at 3 mm (Lee+2008)

Simultaneous Multi-frequency mm-VLBI observation of AGNs is Unique

• Most of AGNs are variable on time scales

• Simultaneous observations at multi-frequencies can provide important clues on physical conditions, especially in particular compact systems

MASK Pilot Observations • Common sources of ALMA & KVNCS Calibrators (Dec<0°)

– 76% VLBI detection (57/75 detection at 3mm)

Raw 86GHz Phase FPTed 86GHz Phase Calibrated 86GHz Phase

24 hour experiment

(Known) K-band Calibrators (858) Petrov et al. (2007), Lanyi et al. (2010), Petrov et al. (2011), Petrov (2012), Petrov et al. (2012)

Sky Coverage ~ 68% (Dec>32.5°)

KVN Single Dish Survey (1533) Sky Coverage ~ 99% (Dec>32.5°) - more than two sources overlap ~ 89% - single source area ~ 10% - empty area ~ 1%

circle radius ~ 5° (J.A. Lee+ accepted)

KVN K-band Single

Dish Calibrator Survey

(J.A. Lee)

First Detection Statistics of MASK Observations - Preliminary Results-

• 2016A season (2016 April – September)

– Detection test for KVNCS common sources (154 sources) in CARMA & SMA catalogues

– Observations: All 154 sources have been observed !!

• Detection results for all 154 sources

– W-band: 5 src detected by only KW, 1 src detected by only QW

– D-band: 1 src detected by only KD, 6 src detected by only QD

( ) # of non-detected sources

FPT(total 154src) # of Detection Detection Rate

KQ 150 (4) 97%

KW 137 (17) 89%

KD 98 (56) 64%

QW 133 (21) 86%

QD 103 (51) 67%

First Detection Statistics of MASK Observations - Preliminary Results-

• 2016A season (2016 April – September)

– Detection test for KVNCS common sources (154 sources) in CARMA & SMA catalogues

– Observations: All 154 sources have been observed !!

• Detection results for all 154 sources

– W-band: 5 src detected by only KW, 1 src detected by only QW

– D-band: 1 src detected by only KD, 6 src detected by only QD

( ) # of non-detected sources

FPT(total 154src) # of Detection Detection Rate

KQ 150 (4) 97%

KW 137 (17) 89%

KD 98 (56) 64%

QW 133 (21) 86%

QD 103 (51) 67%

Detected sources @ W/D band from K-band FPT

MASK as a KVN Legacy Program

• Large science projects, not reproducible by any reasonable number or combination of smaller observations

• General and lasting importance to the broad astronomical community with KVN data yielding a substantial and coherent database

• Enabling timely and effective opportunities for follow-on observations and for archival research

• Maximizing the KVN Uniqueness (4-freq. simultaneous VLBI) • What KVN (instrument) CAN DO

What KVN (instrument) canNOT do • Large & homogeneous DB for statistical study of a broad range of

astrophysical & cosmological issues

• 1st MASK detection survey (2016 – 2017)

– 30min per source, total ~1500 sources

– net obs. time 750 hr (~ 1000 hr incl. overhead)

– So far, 10% (~150 sources) completed

• 2nd MASK Imaging survey (2018 -)

– based on 1st detection survey results

On-going Works • Data reduction and performance evaluation

– error estimation of amplitude calibration & pipeline updates

• 1st MASK Catalog Release (~150 sources, pilot survey)

• Contructing MASK DB

• 2nd MASK survey : KVNCS common sources with (up to date) ALMA calibrators

• Multi-wavelength database (gamma-ray to radio) Synergy!

MOJAVE (Lister & Homan 2005)

VLBI Polarimetry

(Lanyi et al. 2010)

Celestial Reference Frame

Astrometry & VLBI Calibrators - ICRF / Accurate source position

Statistical Study - (high resolution) source structure / compactness / brightness temperature / spectral index - population / classification - r-ray connection, variability - polarimetry - cosmological evolution / AGN evolution

Credit: Roen Kelly

Origin of Jets: Understanding BH-Disk-Jet

(Lee et al. 2016)

Brightness Temp. vs Frequency (Ojha et al. 2010)

TANAMI Survey

Statistical study of AGN classification & γ-ray connection

compactness/structure, variability, Tb

(Kovalev et al. 2005)

MASK Synergies

For the most powerful mm-VLBI network

People Role

Taehyun Jung Coordinator

Do-Young Byun Advisor (KVN PI)

Bong Won Sohn Advisor, Database

Dongsoo Ryu Advisor

Minsun Kim Sample & Database

Woojin Kwon Sample & Database

Cristian Saez de Cea Sample & Database

Jeong Ae Lee Sample & Database

Jan Wagner Data analysis, Pipeline

Guangyao Zhao Data analysis, Pipeline

Kiyoaki Wajima Data analysis

Ilje Cho Data analysis, Scheduling

Dawoon Jeong Data analysis

Jongsoo Kim Advisor

MASK Team Members

MASK will provide most extensive mm-VLBI catalog at multiple friquencies and play an important role to uncover mm-VLBI sky

Thank you !

multi-frequency agn survey with kvn - ホーム | 国立天 … ae lee, ilje cho, dawoon jeong,...

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