Radio-to-Gamma Ray Monitoring of Mkn 421 and Mkn 501: Source - - PowerPoint PPT Presentation
Radio-to-Gamma Ray Monitoring of Mkn 421 and Mkn 501: Source Variability N. Nowak, D. Paneque, U. Barres de Almeida, N. Strah, D. Tescaro On behalf of the Fermi-LAT, MAGIC, VERITAS and other collaborations and groups involved in the
On behalf of the Fermi-LAT, MAGIC, VERITAS and other collaborations and groups involved in the multiwavelength campaigns
Blazars:
bump not yet identified unambiguously. ➡ simultaneous observations of blazars over the whole wavelength range (Radio - TeV) over a long time period needed (mostly in low state).
Mrk 421 and Mrk 501:
➡ ideal candidates for multiwavelength studies
4.5 months long multiwavelength campaigns in 2009 (PI: David Paneque):
low state throughout the campaigns
MAGIC, Whipple, VERITAS, Fermi-LAT, Swift/BAT, RXTE/PCA, Swift/XRT, Swift/UVOT, GASP-WEBT, GRT, ROVOR, New Mexico Skies, MITSuME, OAGH, WIRO, SMA, VLBA, Noto, Metsähovi, OVRO, Medicina, UMRAO, RATAN-600, Effelsberg
[Hz])
10 15 20 25
Time [MJD]
54850 54900 54950 55000
Radio IR O-UV X-rays
[Hz])
10 15 20 25
Time [MJD]
54900 54950 55000 55050
Radio IR O-UV X-rays
Abdo et al., 2011, ApJ, 736, 131 Abdo et al., 2011, ApJ, 727, 129
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[erg cm
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MAGIC Fermi Swift/BAT RXTE/PCA Swift/XRT
Swift/UVOT ROVOR NewMexicoSkies MITSuME GRT GASP WIRO OAGH
SMA VLBA_core(BP143) VLBA(BP143) VLBA(BK150) Metsahovi Noto VLBA_core(MOJAVE) VLBA(MOJAVE) OVRO RATAN Medicina Effelsberg
Abdo et al., 2011, ApJ, 736, 131
high-energy bump
covered by Fermi- LAT + MAGIC
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[erg cm
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MAGIC VERITAS VERITAS_flare Fermi
Swift/BAT RXTE/PCA Swift/XRT
Swift/UVOT BradfordRoboticTelescope GASP GRT MITSuME ROVOR WIRO OAGH CampoImperatore
SMA VLBA(BP143) VLBA_core(BP143) VLBA_core_ellipsefit(BP143) VLBA(BK150) VLBA_core(BK150) Noto Metsahovi Medicina VLBA(MOJAVE) VLBA_Core(MOJAVE) OVRO RATAN UMRAO Effelsberg
Abdo et al., 2011, ApJ, 727, 129
host galaxy 3-day spectrum
VERITAS low-state spectrum (flare excluded)
high-energy bump
covered by Fermi- LAT + MAGIC + VERITAS
model with 2 breaks in the electron spectrum
properties of the electron population, ...) are very similar for both objects ➡ common properties of jets and acceleration mechanisms in blazars
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F [erg s
Mrk 421 SED with SSC model fits
Abdo et al., 2011, ApJ, 736, 131
1010 1012 1012 1014 1014 1016 1016 1018 1018 1020 1020 1022 1022 1024 1024 1026 1026 1028 1014 1014 1013 1013 1012 1012 1011 1011 1010 1010 109
Ν Hz ΝFΝ erg cm 2 s 1
Mrk 501 SED with SSC model fits
host galaxy Abdo et al., 2011, ApJ, 727, 129
MJD
54800 54840 54880 54920 54960 55000
Flux [Jy]
Effelsberg 110mm Effelsberg 13mm Effelsberg 20mm Effelsberg 28mm Effelsberg 36mm Effelsberg 60mm Effelsberg 9mm Metsähovi 37GHz Medicina 8GHz Noto 22GHz Noto 8GHz OVRO 15GHz 0.1 0.2 0.3 0.4 0.5 0.6 0.7
frequencies
Effelsberg Metsähovi Noto OVRO Medicina
I R V B
MJD
54800 54840 54880 54920 54960 55000
Flux [mJy]
10 15 20 25 30 35 40 45
ROVOR B MITSuME Ic MITSuME Rc MITSuME g GRT B GRT I GRT R GRT V GASP Steward V
MJD 54800 54840 54880 54920 54960 55000 Flux [mJy] 25 30 35 40 45 50
OAGH H OAGH J OAGH K Wiro J Wiro K
wavelengths provided by many telescopes around the world
Swift RXTE
MJD 54800 54840 54880 54920 54960 55000 Flux [mJy] 6 8 10 12 14
UVOT M2 UVOT W1 UVOT W2
with time, significant variability
variability amplitudes
Flux [counts/s ]
s
Flux [ergs cm
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
10 ×
RXTE/PCA (2 - 10 keV) Swift/XRT (0.3 - 2 keV) Swift/XRT (2 - 10 keV)
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
RXTE/ASM
MJD
54800 54840 54880 54920 54960 55000 0.0005 0.001 0.0015 0.002 0.0025
Swift/BAT
] ] Flux [counts/s
]
s
Flux [photons cm 0.04 0.06 0.08 0.1 0.12 0.14
10 ×
MAGIC
MJD 54800 54840 54880 54920 54960 55000 ]
Flux [photons minute 0.2 0.4 0.6 0.8 1 1.2
Whipple
MJD 54800 54840 54880 54920 54960 55000 ]
s
Flux [photons cm 0.04 0.08 0.12 0.16
10 ×
Fermi-LAT
variability
Fermi MAGIC Whipple
E>300MeV, 2 day bins E>300GeV E>400GeV
MJD
54900 54940 54980 55020 55060
Flux [Jy]
0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Effelsberg 110mm Effelsberg 13mm Effelsberg 20mm Effelsberg 28mm Effelsberg 36mm Effelsberg 60mm Effelsberg 7mm Effelsberg 9mm Medicina 22GHz Medicina 8GHz Metsähovi 37GHz GASP 14GHz GASP 5GHz GASP 8GHz Noto 43GHz Noto 8GHz SMA 225GHz OVRO
many different frequencies
Effelsberg Metsähovi Noto OVRO Medicina
I R V B
MJD
54900 54940 54980 55020 55060
Flux [mJy]
5 10 15 20 25 30
ROVOR B ROVOR I ROVOR R ROVOR V GASP R GRT B GRT R GRT V MITSuME Ic MITSuME Rc MITSuME g Steward V
MJD 54900 54940 54980 55020 55060 Flux [mJy] 30 35 40 45 50 55 60 65
GASP H GASP J GASP K OAGH H OAGH J OAGH Ks Wiro J Wiro K
wavelengths provided by many telescopes around the world
Swift RXTE
significant variability
MJD 54900 54940 54980 55020 55060 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8
UVOT M2 UVOT W1 UVOT W2
Flux [mJy]
]
s
Flux [ergs cm 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2
10 × MJD 54900 54940 54980 55020 55060 ] Flux [counts/s 0.1 0.2 0.3 0.4
] Flux [counts/s
0.0002 0.0004 0.0006 0.0008 0.001 0.0012
RXTE/PCA (2 - 10 keV) Swift/XRT (0.3 - 2 keV) Swift/XRT (2 - 10 keV) RXTE/ASM Swift/BAT Swift/XRT PC mode (0.3 - 2 keV) Swift/XRT PC mode (2 - 10 keV)
Large flare in VHE around MJD 54952 (May 1st, 2009). No obvious correlation with other wavelengths.
54900 54940 54980 55020 55060
]
s
Flux [photons cm 10 20 30 40 50
10 × Fermi (15 day bins) Fermi (30 day bins) ]
s
Flux [photons cm 0.05 0.1 0.15 0.2
10 × MAGIC VERITAS
MJD 54900 54940 54980 55020 55060
] Flux [photons/minute 0.5 1 1.5 2
Whipple
MJD
Fermi MAGIC Whipple
E>300MeV E>300GeV E>400GeV
Large flare in VHE around MJD 54952 (May 1st, 2009). No obvious correlation with other wavelengths.
Flare
without X-ray counterpart
54900 54940 54980 55020 55060
]
s
Flux [photons cm 10 20 30 40 50
10 × Fermi (15 day bins) Fermi (30 day bins) ]
s
Flux [photons cm 0.05 0.1 0.15 0.2
10 × MAGIC VERITAS
MJD 54900 54940 54980 55020 55060
] Flux [photons/minute 0.5 1 1.5 2
Whipple
MJD
Fermi MAGIC Whipple
E>300MeV E>300GeV E>400GeV
Flare
without X-ray counterpart
EVPA:
in 3 days before flare
➡ indicates common origin for optical and
γ-ray emission (e.g., Marscher et al. 2010)
]
s
Flux [photons cm 0.05 0.1 0.15 0.2
10 × MAGIC VERITAS
MJD 54900 54940 54980 55020 55060
] Flux [photons/minute 0.5 1 1.5 2
Whipple
P (%) 1 2 3 4 5 6 54900 54940 54980 55020 55060 ° EVPA( ) 15 20 25 30 35 MJD
Steward Observatory
Flare
without X-ray counterpart
EVPA:
in 3 days before flare
➡ indicates common origin for optical and
γ-ray emission (e.g., Marscher et al. 2010)
]
s
Flux [photons cm 0.05 0.1 0.15 0.2
10 × MAGIC VERITAS
MJD 54900 54940 54980 55020 55060
] Flux [photons/minute 0.5 1 1.5 2
Whipple
P (%) 1 2 3 4 5 6 54900 54940 54980 55020 55060 ° EVPA( ) 15 20 25 30 35 MJD
Further details on this flaring event can be found in Pichel & Paneque, Proc. ICRC 2011, arXiv:1110.2549v1
Steward Observatory
10 12 14 16 18 20 22 24 26 28
var
0.2 0.4 0.6 0.8 1
Fermi ROVOR NMSkies MITSuME GRT GASP OAGH UVOT Wiro Effelsberg Metsähovi Medicina OVRO Whipple MAGIC PCA ASM BAT XRTa XRTb Steward V
Largest variability in X-rays
Low but significant variability at all wavelengths
Fvar =
err >
< Fγ >2
Fractional variability Fvar (Vaughan et al. 2003)
host galaxy subtracted (R band; Nilsson et al. 2007)
10 12 14 16 18 20 22 24 26 28 0.2 0.4 0.6 0.8 1
Fermi (15 day) Fermi (30 day) ROVOR GASP GRT MITSuME OAGH UVOT Wiro Metsähovi GASP SMA OVRO MAGIC PCA ASM BAT XRTa XRTb Steward V VERITAS Whipple Whipple (flare removed) VERITAS (flare removed)
var
Largest variability in VHE due to flare in May 2009
Variability increases with frequency
host galaxy subtracted (R band; Nilsson et al. 2007)
Fermi-LAT: dominated by variability at 30 day timescales
What is the error in Fvar introduced by this? How many flux measurements are needed to obtain a reliable Fvar estimate?
What is the error in Fvar introduced by this? How many flux measurements are needed to obtain a reliable Fvar estimate?
log(frequency [Hz]) 10 12 14 16 18 20 22 24 26 28
var
F 0.2 0.4 0.6 0.8 1
var
F and its uncertainty calculated using Vaughan et al. 2003 delete-d jackknife estimate and variance, d=sqrt(n) Fermi UVOT Metsähovi OVRO Whipple MAGIC PCA ASM BAT XRTa XRTb
PRELIMINARY
d randomly selected flux measurements removed from each lightcurve without replacement (Jackknife)
What is the error in Fvar introduced by this? How many flux measurements are needed to obtain a reliable Fvar estimate?
log(frequency [Hz]) 10 12 14 16 18 20 22 24 26 28
var
F 0.2 0.4 0.6 0.8 1
var
F and its uncertainty calculated using Vaughan et al. 2003 delete-d jackknife estimate and variance, d=sqrt(n) Fermi UVOT Metsähovi OVRO Whipple MAGIC PCA ASM BAT XRTa XRTb
PRELIMINARY
d randomly selected flux measurements removed from each lightcurve without replacement (Jackknife)
➡no significant change in the Fvar values
What is the error in Fvar introduced by this? How many flux measurement are needed to obtain a reliable Fvar estimate?
PRELIMINARY
d randomly selected flux measurements removed from each lightcurve without replacement (Jackknife)
log(frequency [Hz]) 10 12 14 16 18 20 22 24 26 28 0.2 0.4 0.6 0.8 1
var
F
var
F and its uncertainty calculated using Vaughan et al. 2003 delete-d jackknife estimate and variance, d=sqrt(n) Fermi UVOT Metsähovi OVRO MAGIC PCA ASM BAT XRTa XRTb VERITAS Whipple
➡no significant change in the Fvar values
n n-d 0.2 0.4 0.6 0.8 1 Fvar
0.1 0.2 0.3 0.4 0.5
ASM
n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.1 0.2 0.3 0.4 0.5
PCA
n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.05 0.1 0.15 0.2 0.25 0.3
GASP
n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.2 0.25 0.3 0.35 0.4
UVOT W2
n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45
Whipple
n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.1 0.2 0.3 0.4 0.5 0.6
Metsähovi
PCA GASP UVOT W2 Whipple Metsähovi
n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.05 0.06 0.07 0.08 0.09 0.1 0.11 0.12 0.13 n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 n n-d 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Fvar
0.1 0.2 0.3 0.4 n n-d 0.2 0.4 0.6 0.8 1 Fvar
0.05 0.1 0.15 0.2 0.25 n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.2 0.4 0.6 0.8 1 1.2 n n-d 0.2 0.4 0.6 0.8 1 Fvar 0.05 0.1
Mrk 421: clear correlation between VHE and X-rays
Discrete correlation function (Edelson & Krolik 1988)
Mrk 501: no correlation between VHE and X-rays
Mkn 421 MAGIC – Whipple –200 –100 100 200 –1.0 0.5 –0.0 –0.5 1.0 ∆τ [d] DCF Mkn 421 ASM – PCA –200 –100 100 200 –1.0 0.5 –0.0 –0.5 1.0 ∆τ [d] DCF Mkn 421 MAGIC – PCA –200 –100 100 200 –1.0 0.5 –0.0 –0.5 1.0 ∆τ [d] DCF Mkn 501 Whipple – PCA –200 –100 100 200 –1.0 0.5 –0.0 –0.5 1.0 ∆τ [d] DCF Mkn 501 XRT – PCA –200 –100 100 200 –1.0 0.5 –0.0 –0.5 1.0 ∆τ [d] DCF Mkn 501 VERITAS – Whipple –200 –100 100 200 –1.0 0.5 –0.0 –0.5 1.0 ∆τ [d] DCF
X-rays
polarisation and EVPA
VHE due to flare
shows that Fvar is not significantly affected by sampling, gaps and different number of flux measurements
correlation functions) under way
Mrk 501: Stawarz’s code
Abdo et al., 2011, ApJ, 727, 129
Mrk 421: Finke’s code
Abdo et al., 2011, ApJ, 736, 131
log(frequency [Hz]) 10 12 14 16 18 20 22 24 26 28 0.2 0.4 0.6 0.8 1
and its uncertainty calculated using Vaughan et al. 2003
var
F moving block jackknife estimate and variance
var
F
Fermi UVOT Metsähovi OVRO Whipple MAGIC PCA ASM BAT XRTa XRTb
PRELIMINARY
PRELIMINARY
log(frequency [Hz]) 10 12 14 16 18 20 22 24 26 28 0.2 0.4 0.6 0.8 1
and its uncertainty calculated using Vaughan et al. 2003
var
F moving block jackknife estimate and variance
var
F
Fermi UVOT Metsähovi OVRO MAGIC PCA ASM BAT XRTa XRTb VERITAS Whipple