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

Transcription

1 Multi-frequency AGN Survey with KVN Finding more high-frequency sources & Maximizing the KVN uniqueness KVN Legacy Program (planned) 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 Challenges of AGN Jets, 20 Jan. NAOJ, Mitaka, Tokyo

2 Intro Radio Surveys

3 Radio Sources Interferometer 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 FIRST NVSS SUMSS WENSS Frequency 1400 MHz 1400 MHz 843 MHz 325 MHz Area (deg 2 ) 10,000 33,700 8,000 10,100 Resolution Detection limit 1 mjy 2.5 mjy 3.5 mjy 15 mjy Coverage δ > +22 δ > -40 δ > -30 δ > +30 Sources/deg # of Sources 946,432 1,773, , ,420 References Becker+1995 Condon+1998 Bock+1998 Rengelink

4 Radio Sources VLBI > 3400 sources are available

5 Number of Sources Radio Fundamental Catalog of Compact Radio Sources (L. Petrov) 11,448 (up to date) Time (year)

6 VLBI Surveys Name Wavelength # of Sources Reference CJF survey 18 & 6 cm 293 Pollack et al ICRF/RDV 13 & 3.6 cm ~ 500 Ojha et al VLBA Calibrator Survey 13 & 3.6 cm > 3400 Kovalev et al VSOP VLBApls 6 cm 374 Fomalont et al VSOP Survey 6 cm ~ 300 Dodson et al VIPS 6 cm 1127 Helmboldt et al cm Survey 2 cm 250 Kovalev et al MOJAVE 2 cm > 133 Lister & Homan 2005 VERA FSS / GaPS 1.35 cm 500 Petrov et al ICRF 22 & 43 GHz 1.37 & 0.7 cm ~100 Lanyi et al GMVA 3mm 3 mm 123 Lee et al TANAMI 3.5 & 1.3 cm 80 Ojha et al KVN Q-CAL survey 7 mm 638 Petrov et al 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.)

7 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)

8 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

9 mm-vlbi observations 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

10 Difficulties in mm-vlbi 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 Sensitivity (Image) ΔI m =SEFD/[η s (N (N 1) Δν t int ) 1/2 ] Jy/beam

11 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 Coherence Coherence Function VLBI Sensitivity Pico Veleta Onsala baseline Source : BL Lac Frequency : 86 GHz (A. Roy) Coherence Time *Typical value of atmospheric phase stability ~ 10-13

12 Korean VLBI Network Simultaneous Multi-Frequency VLBI System

13 KVN Yonsei Observatory KVN Ulsan Observatory KVN Tamna Observatory

14 4Ch Yonsei Multi-Frequency Receiving System 22GHz Beams from antenna 3GHz 129GHz 86GHz Band K Q W D Freq. Range Trx (K) (40-50 KUS) Full Polarization Han et al. (2008)

15 Frequency Phase Transfer (FPT) 2 ( ) h h h h str g C inst trop ion LO 2 ( ) l l l l str g C inst trop ion LO Self-calibration at lower frequency l 2 ( ) l str l g C inst trop ion LO h l r h / r l slow varying term 2 2 h str g g h h 0 ion LO LO h l h 2 h( h l ) 2 1 ( ) 2 2 h l l l h l Source Structure Core-shift diff in maser lines ionosphere instrument By doing Self-calibration again for longer solution interval, we can get an image at higher frequency

16 High frequency VLBI Phase Calibration by Lower Frequency Phase Solutions Fringe Solution SNRs at 22GHz (solint 0.3) NRAO C C279 3C345 NRAO530 SGR-A 3C C NRAO512 FAS BLLAC NRAO150 FPT applied using K-band solint hours 43GHz FPT applied using Q-band solint GHz FPT applied suing K-band solint GHz NRAO C C279 3C345 NRAO530 SGR-A 3C C NRAO512 FAS BLLAC NRAO hours

17 φ high ν h ν l φ low non-dispersive characteristic of troposphere Power of Simultaneous Multi-Frequency Receiving System 129 GHz 86 GHz SNR~213 (~90% of theoretical SNR) 43 GHz 22 GHz 30min Ceff 22GHz 43GHz 86GHz 129GHz 22 GHz GHz GHz GHz

18 φ high ν h ν l φ low non-dispersive characteristic of troposphere Power of Simultaneous Multi-Frequency Receiving System 129 GHz 86 GHz SNR~213 (~90% of theoretical SNR) 43 GHz 22 GHz 30min 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 Ceff 22GHz 43GHz 86GHz 129GHz 22 GHz GHz GHz GHz

19 KVN Sensitivity by FPT ΔI m =SEFD/[η s (N (N 1) Δν t int ) 1/2 ] Jy/beam 1Gbps Multi-Freq. Obs Mode Frequency Band 22 GHz 43 GHz 86 GHz 129 GHz Bandwidth (MHz) 64 (Total 256MHz ~ 1Gbps) System temperature (K) SEFD (Jy) Integration time (sec) (30 min) Sensitivity (mjy) σ Sensitivity (mjy) Gbps Multi-Freq. Obs Mode Frequency Band 22 GHz 43 GHz 86 GHz 129 GHz Bandwidth (MHz) 512 MHz for each band System temperature (K) SEFD (Jy) Integration time (sec) (30 min) Sensitivity (mjy) σ Sensitivity (mjy) Aperture efficiency : K ~ 0.6, Q ~ 0.6, W ~ 0.45, D ~ 0.4

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21 First KVN s 4-Frequency Simultaneous Observation VLBI Images 21.7GHz Peak ~ 26.4 Jy/beam Beam 8.5 x 3.5 mas Phase reference 43.4GHz Peak ~ 20.6 Jy/beam Beam 3.12 x 1.78 mas Source: 3C GHz Peak ~ 12.7 Jy/beam Beam 1.59 x 0.87 mas GHz Peak ~ 5.0 Jy/beam Beam 1.09 x 0.58 mas /86/130GHz visibility phases are calibrated by 22GHz s

22 Correlated Amplitude (mjy) Example: J KVN single dish flux at 22GHz ~ 0.3 Jy (No SD detection at 43GHz) UV distance (Mega wavelength) 22 GHz 43 GHz KT-KU 86 GHz 129 GHz 22 GHz 43 GHz KT-KY 86 GHz 129 GHz 22 GHz 43 GHz KU-KY 86 GHz 129 GHz

23 Amplitude (mjy) Credit: UV distance B. W. Sohn (Mega wavelength) Example: J GHz KVN single dish flux at 22GHz ~ 0.3 Jy (no detection at 43GHz) KT-KU GHz 86 GHz 129 GHz KT-KY KU-KY

24 KVN Sensitivity by FPT ΔI m =SEFD/[η s (N (N 1) Δν t int ) 1/2 ] Jy/beam Overcome the difficulties in the atmosphere 1Gbps Multi-Freq. Obs Mode Frequency Band 22 GHz 43 GHz 86 GHz 129 GHz Bandwidth (MHz) 64 (Total 256MHz ~ 1Gbps) System temperature (K) SEFD (Jy) Integration time (sec) (30 min) Sensitivity (mjy) σ Sensitivity (mjy) Gbps Multi-Freq. Obs Mode Frequency Band 22 GHz 43 GHz 86 GHz 129 GHz Bandwidth (MHz) 512 MHz for each band System temperature (K) SEFD (Jy) Integration time (sec) (30 min) Sensitivity (mjy) σ Sensitivity (mjy) Aperture efficiency : K ~ 0.6, Q ~ 0.6, W ~ 0.45, D ~ 0.4

25 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

26 Multi-frequency AGN Survey with KVN Goal: Constructing Multi-Frequency VLBI Catalog of AGNs Utilizing KVN s uniqueness & playing a leading role in mm-vlbi Samples based on KVNCS J. A. Lee (submitted) Sample: 1533 sources Known K-band VLBI sources KVN K-band fringe survey 426 ( 43 common sources)

27 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 multifrequencies can provide important clues on physical conditions, especially in particular compact systems

28 MASK Pilot Observations Common sources of ALMA & KVNCS Calibrators (Dec<0 ) 76% VLBI detection (57/75 detection at 3mm) 24 hour experiment Raw 86GHz Phase FPTed 86GHz Phase Calibrated 86GHz Phase

29 MASK Pilot Observations Common sources of ALMA & KVNCS Calibrators (Dec<0 ) 76% VLBI detection (57/75 detection at 3mm) 24 hour experiment Raw 86GHz Phase FPTed 86GHz Phase Calibrated 86GHz Phase

30 KVN K-band Single Dish Calibrator Survey (J.A. Lee) (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)

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32 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 K W, 1 src detected by only Q W D-band: 1 src detected by only K D, 6 src detected by only Q D ( ) # of non-detected sources FPT(total 154src) # of Detection Detection Rate K Q 150 (4) 97% K W 137 (17) 89% K D 98 (56) 64% Q W 133 (21) 86% Q D 103 (51) 67%

33 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 K W, 1 src detected by only Q W D-band: 1 src detected by only K D, 6 src detected by only Q D ( ) # of non-detected sources FPT(total 154src) # of Detection Detection Rate Detected W/D band from K-band FPT K Q 150 (4) 97% K W 137 (17) 89% K D 98 (56) 64% Q W 133 (21) 86% Q D 103 (51) 67%

34 MASK as a KVN Legacy Program 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 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 1 st MASK detection survey ( ) 30min per source, total ~1500 sources net obs. time 750 hr (~ 1000 hr incl. overhead) So far, 10% (~150 sources) completed 2 nd MASK Imaging survey (2018 -) based on 1 st detection survey results

35 On-going Works Data reduction and performance evaluation error estimation of amplitude calibration & pipeline updates 1 st MASK Catalog Release (~150 sources, pilot survey) Contructing MASK DB 2 nd MASK survey : KVNCS common sources with (up to date) ALMA calibrators Multi-wavelength database (gamma-ray to radio) Synergy!

36 MASK Synergies VLBI Polarimetry Credit: Roen Kelly (Lee et al. 2016) Brightness Temp. vs Frequency compactness/structure, variability, T b Origin of Jets: Understanding BH-Disk-Jet 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 (Lanyi et al. 2010) MOJAVE (Lister & Homan 2005) TANAMI Survey Statistical study of AGN classification & γ-ray connection (Ojha et al. 2010) (Kovalev et al. 2005) Celestial Reference Frame

37 MASK will provide most extensive mm-vlbi catalog at multiple friquencies and play an important role to uncover mm-vlbi sky Thank you! MASK Team Members People Taehyun Jung Do-Young Byun Bong Won Sohn Dongsoo Ryu Minsun Kim Woojin Kwon Cristian Saez de Cea Jeong Ae Lee Jan Wagner Guangyao Zhao Kiyoaki Wajima Ilje Cho Dawoon Jeong Jongsoo Kim Role Coordinator Advisor (KVN PI) Advisor, Database Advisor Sample & Database Sample & Database Sample & Database Sample & Database Data analysis, Pipeline Data analysis, Pipeline Data analysis Data analysis, Scheduling Data analysis Advisor For the most powerful mm-vlbi network