by the iMOGABA and AiMOGABA (A KVN Key Science Program) Sang-Sung - - PowerPoint PPT Presentation

An Interesting Story of Gamma-Ray Bright AGNs 
 by the iMOGABA and … AiMOGABA 


(A KVN Key Science Program)

Sang-Sung Lee (KASI) and the iMOGABA team

2018 September 6 East Asia VLBI Workshop Pyeoung Chang

The Discoveries

• Discoveries of non-stellar activities

– Strong broad emission line in NGC 1068 
 (Fath 1909) – Jet in M87 (Curtis 1918): 


apparently connected with the nucleus 
 by a thin line of matter


M87 (Virgo)

출처: http://server7.wikisky.org/snapshot? img_size=&img_res=&ra=12.5138&de=12.3896&angle=0.0293&projection=tan& rotation=0.0&survey=astrophoto&img_id=905632&width=2160&height=2160 &img_borders=&interpolation=bicubic&jpeg_quality=0.8

Spectrum of NGC 1068


http://homework.uoregon.edu/pub/class/321/sspher.html

Unified scheme of AGN

Graphic courtesy of Marie-Luise Menzel (MPE) Blazars… Doppler boosted, violent


(Angel & Stockman 80)

AGNs visible on Gamma-ray sky

75 % are blazars

Ajello+17

Scientific Goals

• Studying the origins of the gamma-flares

– What is the location of the gamma-ray flares?

: Down stream the relativistic jets? (e.g., an orphan flare) : much inner region of the jets? (e.g., radio counter part time-lagged)

– What cause the gamma-ray flares of AGNs?

: A relativistic jet of high energy plasma (e.g., Marscher et al. 2008) : Doppler boosting of synchrotron radiation of the jet (e.g., Dermer 1995) : Inverse Compton scattering by relativistic electrons

Origins of Gamma-ray Flares in AGNs


(A KVN Key Science Program)

• Project I (Single Dish): MOGABA (Monitoring of Gamma-ray Bright AGNs)

– radio polarization light curves after a gamma-ray flare of 32 AGNs – dense monitoring at 22, 43, 86 (129) GHz – weekly monitoring for 3-4 months – Lee et al. 2013, Kang et al. 2015, JKAS, 48, 257 (Case study for 3C 279)

• Project II (VLBI): iMOGABA (Interferometric MOGABA)

– Monthly VLBI monitoring of the MOGABA sources (~34) – correlated flux of inner-jet structure after gamma-ray flare – Multi-freq. (22/43/86/129GHz) monitoring – Requirement:
 accurate amplitude calibration with careful Tsys measurements 
 (antenna gain measurement every hour) – Lee et al. 2016, ApJS, 227, 8 (Project overview and single-epoch results)

Collaborations of our KSP

(17 people)

• KASI (Korea)

– Do-Young Byun (MOGABA data reduction pipeline) – Jeffrey Hodgson (iMOGABA data reduction pipeline, 3C84) – Sincheol Kang (MOGABA observations/data reduction, iMOGABA data reduction,1156+295) – Jeong-Sook Kim (CygX-3) – Sang-Hyun Kim (MOGABA observations/data reduction, iMOGABA data reduction, CTA102) – Soon-Wook Kim (CygX-3) – Jee Won Lee (iMOGABA data reduction, 0716+714/OJ287) – Sang-Sung Lee (PI) – Kiyoaki Wajima (iMOGABA data reduction, faint AGNs) – Guangyao Zhao (iMOGABA with frequency phase transfer)


• Seoul National University (Korea)

– Juan-Carlos Algaba-Marcos (iMOGABA data reduction, 1633+382) – Dae-Won Kim (iMOGABA data reduction, BL Lac/1749+096) – Jongho Park (iMOGABA data reduction, 1510-089) – Sascha Trippe (bright AGNs)


• Chungbuk National University (Korea)

– Sung-Min Yoo (iMOGABA data reduction, 3C 279)


• Kogakuin University (Japan)

– Motoki Kino (bright AGNs)


• MPIfR (Germany)

– Jae-Young Kim (iMOGABA data reduction, M87)

including 6 students + 5 postdocs

References

• Published (16 SCI papers, since 2015)

– First detection of 350 micron polarization of 3C 279 (Lee et al. 2015, ApJL) – iMOGABA II: Frequency Phase Transfer (Algaba et al., 2015 JKAS, 14 citations) – Amplitude correction factors of KVN (Lee et al. 2015 JKAS, 14 citations) – Polarization monitoring of 3C 279 (Kang et al. 2015 JKAS, 7 citations) – The KVN Pipeline (Hodgson et al. 2016 JKAS, 9 citations) – Detection of mm polarization IDV of S5 0716+714 (Lee et al. 2016 A&A Letter) – iMOGABA I: Single-epoch imaging results (Lee et al. 2016 ApJS) – Proving the gamma-ray IDV in 3C279 (Rani et al. 2017 MNRAS) – iMOGABA : S5 0716+714 (Lee et al. 2017 ApJ) – iMOGABA : BL Lac (Dae-Won Kim et al. 2017 JKAS, 3 citations) – iMOGABA : 1633+382 I (Algaba et al. 2018 ApJ) : highlights – iMOGABA : FPT2 (Zhao et al. 2018 AJ) : highlights – iMOGABA : 3C 84 (Hodgson et al. 2018 MNRAS) : highlights – iMOGABA : M87 (Jae-Young Kim et al. 2018 A&A Letter) : highlights – iMOGABA : 1633+382 II (Algaba et al. 2018 ApJ) – iMOGABA : 1749+096 (Dea-Won Kim et al. 2018 MNRAS)
 
 


References

• Published (16 SCI papers, since 2015)

– First detection of 350 micron polarization of 3C 279 (Lee et al. 2015, ApJL) – iMOGABA II: Frequency Phase Transfer (Algaba et al., 2015 JKAS, 14 citations) – Amplitude correction factors of KVN (Lee et al. 2015 JKAS, 14 citations) – Polarization monitoring of 3C 279 (Kang et al. 2015 JKAS, 7 citations) – The KVN Pipeline (Hodgson et al. 2016 JKAS, 9 citations) – Detection of mm polarization IDV of S5 0716+714 (Lee et al. 2016 A&A Letter) – iMOGABA I: Single-epoch imaging results (Lee et al. 2016 ApJS) – Proving the gamma-ray IDV in 3C279 (Rani et al. 2017 MNRAS) – iMOGABA : S5 0716+714 (Lee et al. 2017 ApJ) – iMOGABA : BL Lac (Dae-Won Kim et al. 2017 JKAS, 3 citations) – iMOGABA : 1633+382 I (Algaba et al. 2018 ApJ) : highlights – iMOGABA : FPT2 (Zhao et al. 2018 AJ) : highlights – iMOGABA : 3C 84 (Hodgson et al. 2018 MNRAS) : highlights – iMOGABA : M87 (Jae-Young Kim et al. 2018 A&A Letter) : highlights – iMOGABA : 1633+382 II (Algaba et al. 2018 ApJ) – iMOGABA : 1749+096 (Dae-Won Kim et al. 2018 MNRAS)
 
 


Student (UST) Student (SNU) Student (SNU)

Student (SNU)

Upcoming papers

• Submitted (1 SCI papers)

– iMOGABA : Core-blending effect I (Algaba et al. JKAS special issue 2018)


• In preparation (11 SCI papers)

– iMOGABA : Evaluation of imaging quality (Wajima et al. JKAS) – iMOGABA : 1156+295 (Kang et al. ApJ) : See the poster by Kang, Sincheol – iMOGABA : OJ 287 (Lee et al. ApJ) : See the poster by Lee, Jee Won – iMOGABA : Core-blending effect II (Lee et al.) – iMOGABA : Variability time scales (Lee et al.) – iMOGABA : 1510-089 (Park et al. ApJ) – MOGABA : S5 0716+714 (Kang et al. ApJ) – MOGABA : 3C 454.3 (Lee et al. ApJ) – MOGABA : Multi-frequency Polarization Survey (MFPOL) (Lee et al. ApJ) – iMOGABA : CTA 102 (Kim et al. ApJ) – iMOGABA : 3C 279 (Yoo et al. ApJ)


Student (UST) Student (SNU) Student (UST) Student (UST) Student (CNU)

Highlight 1. FPT envies FPT-square

Zhao et al. 2018, AJ

FPT-square (cf. FPT=Frequency Phase Transfer)

– implementing a further phase transfer between two FPT residuals (i.e., calibrating dispersive effect) – Increase the coherence time up to 8 hr (i.e., much higher sensitivity)

FPT-square can help to detect/image sources at high (>43 GHz) frequencies

– Successfully performed with iMOGABA – Suitable also for high frequency all-sky survey (e.g., MASK) phase solution after
 FPT

phase solution after
 FPT-square

Hightlight 2. A Sad Orphan Gamma-ray Flare

Dae-Won Kim et al. 2017, JKAS

We observed BL Lacertae

• 2013 Jan - 2016 Mar

• a radio loud AGN (< 9 Jy)

• gamma-ray bright
• two outbursts on 2013/2015

No radio counter parts

• gamma-ray downstream the jet
• radio counterparts under a

variability

• variation of Doppler boosting
• actually no radio counter part

(a sad orphan flare) A sad orphan flare might occur due to inverse Compton scattering by seed photons from e.g., a jet sheath (ring of fire model)


https://fermi.gsfc.nasa.gov/ssc/data/ access/lat/msl_lc/source/BL_Lac

KVN images

Hightlight 2. A Sad Orphan Gamma-ray Flare

Dae-Won Kim et al. 2017, JKAS

https://fermi.gsfc.nasa.gov/ssc/data/ access/lat/msl_lc/source/BL_Lac

We observed BL Lacertae

• 2013 Jan - 2016 Mar

• a radio loud AGN (< 9 Jy)

• gamma-ray bright
• two outbursts on 2013/2015

No radio counter parts

• gamma-ray downstream the jet
• radio counterparts under a

variability

• variation of Doppler boosting
• actually no radio counter part

(a sad orphan flare) A sad orphan flare might occur due to inverse Compton scattering by seed photons from e.g., a jet sheath (ring of fire model)


KVN images

Highlight 2. A Sad Orphan Gamma-ray Flare

Dae-Won Kim et al. 2017, JKAS

We observed BL Lacertae

• 2013 Jan - 2016 Mar

• a radio loud AGN (< 9 Jy)

• gamma-ray bright
• two outbursts on 2013/2015

No radio counter parts

• gamma-ray downstream the jet
• radio counterparts under a variability
• variation of Doppler boosting
• actually no radio counter part (a sad
• rphan flare)

A sad orphan flare might occur due to inverse Compton scattering by seed photons from e.g., a jet sheath (ring of fire model)


Highlight 3. A Gamma-ray Flare offset from the Radio Emitting Regions Algaba et al. 2018, ApJ We observed 1633+382

• 2012 Mar - 2015 Aug

• a radio loud AGN (< 5 Jy)

• gamma-ray bright
• five outbursts correlated with multi-band

Cross correlation

• flux at different bands are

significantly correlated

• gamma-ray leads radio by

about 70 days (i.e., 40 pc)

• gamma-ray flare offset from

radio emitting regions by 40 pc A happy correlated flare might occur in the inner regions of the jet, due to a shock propagating a radio emitting regions.

Algaba+ submitted

Highlight 3. A Gamma-ray Flare offset from the Radio Emitting Regions Algaba et al. 2018, ApJ We observed 1633+382

• 2012 Mar - 2015 Aug

• a radio loud AGN (< 5 Jy)

• gamma-ray bright
• five outbursts correlated with multi-band

Cross correlation

• flux at different bands are

significantly correlated

• gamma-ray leads radio by

about 70 days (i.e., 40 pc)

• gamma-ray flare offset from

radio emitting regions by 40 pc A happy correlated flare might occur in the inner regions of the jet, due to a shock propagating a radio emitting regions.

Highlight 3. A Gamma-ray Flare offset from the Radio Emitting Regions Algaba et al. 2018, ApJ We observed 1633+382

• 2012 Mar - 2015 Aug

• a radio loud AGN (< 5 Jy)

• gamma-ray bright
• five outbursts correlated with multi-band

Cross correlation

• flux at different bands are

significantly correlated

• gamma-ray leads radio by

about 70 days (i.e., 40 pc)

• gamma-ray flare offset from

radio emitting regions by 40 pc A happy correlated flare might occur in the inner regions of the jet, due to a shock propagating a radio emitting regions.

Highlight 4. An alignment case, 3C84

Hodgson et al. 2018, MNRAS

We observed 3C 84

• 2013 Jan - 2016 Dec

• a radio loud AGN (< 30 Jy)

• gamma-ray bright
• four major outbursts

Cross correlation

• gamma-ray since mid-2015 is

correlated with flux from C3

• gamma-ray outburst may
• ccur in C3

Cross correlation

• gamma-ray since mid-2015 is

correlated with flux from C3

• gamma-ray outburst may
• ccur in C3

Highlight 4. An alignment case, 3C84

Hodgson et al. 2018, MNRAS

We observed 3C 84

• 2013 Jan - 2016 Dec

• a radio loud AGN (< 30 Jy)

• gamma-ray bright
• four major outbursts

Cross correlation

• gamma-ray since mid-2015 is

correlated with flux from C3

• gamma-ray outburst may
• ccur in C3

Highlight 4. An alignment case, 3C84

Hodgson et al. 2018, MNRAS

We observed 3C 84

• 2013 Jan - 2016 Dec

• a radio loud AGN (< 30 Jy)

• gamma-ray bright
• four major outbursts

Highlight 4. An alignment case, 3C84

Hodgson et al. 2018, MNRAS

We observed 3C 84

• 2013 Jan - 2016 Dec

• a radio loud AGN (< 30 Jy)

• gamma-ray bright
• four major outbursts

Cross correlation

• gamma-ray since mid-2015 is

correlated with flux from C3

• gamma-ray outburst may
• ccur in C3

Highlight 5. A Flat Spectrum of the Core in M87

Jae-Young Kim et al. 2018, A&A Letter

We observed M87

• 2012 Dec - 2016 Dec

• a radio loud AGN (< 2 Jy)

• a nearest radio galaxy
• four major outbursts

Highlight 5. A Flat Spectrum of the Core in M87

Jae-Young Kim et al. 2018, A&A Letter

We observed M87

• 2012 Dec - 2016 Dec

• a radio loud AGN (< 2 Jy)

• a nearest radio galaxy
• four major outbursts

A flat spectrum of the core

• the jet base consists of

inhomogeneous multi-energy components

• the flat spectrum extending up

to short millimeter wavelengths implies a strong magnetization in the jet

Highlight 5. A Flat Spectrum of the Core in M87

Jae-Young Kim et al. 2018, A&A Letter

We observed M87

• 2012 Dec - 2016 Dec

• a radio loud AGN (< 2 Jy)

• a nearest radio galaxy
• four major outbursts

Cross correlation

• gamma-ray since mid-2015 is

correlated with flux from C3

• gamma-ray outburst may
• ccur in C3

A flat spectrum of the core

• the jet base consists of inhomogeneous multi-energy components
• the flat spectrum extending up to short millimeter wavelengths

implies a strong magnetization in the jet

AiMOGABA

• Astrometric iMOGABA

– motivation: adding SFPR to iMOGABA – scientific questions:


What causes a wandering radio core in relativistic jets

• A discovery of the jet base wandering in

Mrk 421

• Niinuma et al. 2015
• 20 days after a X-ray flare
• Position shift of 0.51 mas within 39 days
• Another shift of 0.49 mas within 49 days
• Astrometric accuracy of ~ 100 muas

AiMOGABA

• AiMOGABA with KVN (Korea) and Mopra (Austria)

– Baseline: ~8000km (N-S) – KVN-style quasi-optics (+dual pol) to be installed in Mopra – Mopra dedicated to VLBI – Goals: 


Revealing a correlation with a wandering core and its B-field variation

– HE or VHE event may affect opacity of the jets
 (ne, geometry, etc.) – B-field may change due to propagation of any shock by the event

Summary

• A Key Science Program of Korean VLBI Network has been formally launched in

2015 April, aiming at studying the origins of the gamma-ray flares in the radio-loud AGNs, and using a data reduction pipeline with FPT technique.

• We learned the followings about those gamma-ray bright AGNs


– the gamma-ray flares may have sometimes no radio counterparts (orphan flares), indicating the flares might occur due to inverse Compton scattering by seed photons from e.g., a jet sheath (ring of fire model)
 – they may occur in the inner regions of the jet, due to a shock propagating a radio emitting regions, showing strong cross correlation with radio light curves.
 – they may occur both regions (i.e., in the inner jet and downstream the jet) of an individual AGN


감사합니다. THANK YOU.