Gamma-ray bursts in the era of multi-messenger astronomy Zsolt - PowerPoint PPT Presentation

Fermi GRBs’ Sky Distribution ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 46 / 101

BATSE Groups Sky Distribution ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 47 / 101

BATSE Groups Sky Distribution ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 48 / 101

Galactic distribution of 404 GRBs with measured z The disk of the Galaxy hinders the optical follow-up. There’s no significant difference between Northern and Southern Galactic hemispheres’ z distribution. The two-sample Kolmogorov-Smirnov test gives 0.1155 for the p-value. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 49 / 101

3D: radial z distribution from the data GRBs are following the star formation rate (?) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 50 / 101

Large Gamma-ray Burst Cluster at 1 . 6 � z < 2 . 1 Horvath+15 applied angular test on the 8 z /distance groups, and we applied k -th nearest neighbour analysis and the bootstrap point radius method on the dataset. Nearest-neighbour tests identify pairing consistent the large, loose GRB cluster in the redshift range 1 . 6 < z � 2 . 1. The scale on which the clustering occurs is disturbingly large, about 2-3 Gpc: the underlying distribution of matter suggested by this cluster is big enough to question standard assumptions about Universal homogeneity and isotropy. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 51 / 101

Large Gamma-ray Burst Cluster at 1 . 6 � z < 2 . 1 + 90 1.6< z< 2.1 + 60 + 30 360 300 240 180 120 60 0 -30 -60 -90 The distribution of GRBs in the redshift range 1 . 6 < z � 2 . 1. The cluster direction is approx l = 88 o , b = 63 o . ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 52 / 101

The Sky Exposure Function of the GRBs Reconstructed empirical Sky Exposure Function of the 404 GRBs with distance. In normalized units, optimal Gaussian smoothing applied. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 53 / 101

A ring-like structure at 0 . 78 < z < 0 . 86 displayed by GRBs Balázs+16 motivated by the Large Gamma-ray Burst Cluster, analyzed the k -th nearest neighbour in the sample further. Instead of the slices in the redshift space the k -th Next Neighbor Statistics was used to determine the spatial density of the GRBs. The values of k = 8 , 10 , 12 , 14 were used to calculate the mean and variance of the local density at every GRB location. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 54 / 101

k -th nearest neighbour χ 2 k values 40 40 df=8 df=10 30 30 99.9% 99.9% chisquare chisquare 99.0% 20 99.0% 20 95.0% 95.0% 10 10 0 0 0 2000 4000 6000 8000 0 2000 4000 6000 8000 distance (Mpc) distance (Mpc) 40 40 df=12 df=14 99.9% 99.9% 30 30 99.0% 99.0% chisquare chisquare 95.0% 95.0% 20 20 10 10 0 0 0 2000 4000 6000 8000 0 2000 4000 6000 8000 distance (Mpc) distance (Mpc) For k = 8 , 10 , 12 , 14 degrees of freedom, 1000 resamplings. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 55 / 101

A Ring-like structure at 0 . 78 < z < 0 . 86 Angular distribution of GRBs in galactic coordinates for k = 12. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 56 / 101

A Ring-like structure at 0 . 78 < z < 0 . 86 Ring with a diameter of 1720 Mpc, displayed by 9 gamma ray bursts (GRBs) Exceeding by a factor of five the transition scale to the homogeneous and isotropic distribution Major diameter of 43 o , minor diameter of 30 o Distance of 2770 Mpc in the 0 . 78 < z < 0 . 86 redshift range Probability of 2 × 10 − 6 of being the result of a random fluctuation in the GRB count rate. This ring-shaped feature is large enough to contradict the cosmological principle. The physical mechanism responsible for causing it is unknown. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 57 / 101

A Ring-like structure at 0 . 78 < z < 0 . 86 The Ring can be a projection of a spheroidal structure, if each host galaxy has a period of 2 . 5 × 10 8 years during which the GRB rate is enhanced. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 58 / 101

A Ring-like structure at 0 . 78 < z < 0 . 86 Is there any other ring? Ring area versus concentration level Ring area versus concentration level 15 GRB ring GRB ring ● ● ● Concentration level 10 5 ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● 0 0.1 0.2 0.3 0.4 0.5 R (ring area) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 59 / 101

The Sky Exposure Function of the GRBs Reconstructed empirical Sky Exposure Function of the 404 GRBs with distance. In normalized units, optimal Gaussian smoothing applied. Mirrored! ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 60 / 101

The spatial two-point correlation function of GRBs GRB dataset Spatial Two-point Correlation function (normalized) MC simulations with 3 σ errors 8 12 MC simulations with 3 σ errors 10 6 8 6 4 4 2 0 2 -2 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000 0 0 500 1000 1500 2000 2500 3000 3500 4000 comoving distance (Mpc) The spatial two-point correlation function for GRBs. Two GRBs, at a distance of ≈ 56 Mpc GRB RA(deg) Dec(deg) l(deg) b (deg) z GRB020819B 351.8310 6.2655 88.4946 -50.8949 0.410 GRB050803 350.6577 5.7857 86.5225 -50.6999 0.422 ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 61 / 101

Gravitational waves I. GW150914 Triggered on 14/09/2015 09:50:45.391 UTC., z = 0 . 093 (+ 0 . 030 / 0 . 036 ) . ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 62 / 101

Gravitational waves II. LVT151012 Triggered on 02/10/2015 09:54:43.44 UTC, z = 0 . 20 (+ 0 . 09 / − 0 . 09 ) . ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 63 / 101

Electromagnetic transients related to the GW events GW150914: Fermi counterpart (Connaughton+16) Inspired ADWO ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 64 / 101

GW150914 Fermi EM counterpart Energy spectra (Connaughton+16) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 65 / 101

GW150914 Fermi NaI sums: Connaughton+16 4.4-12keV 12-27keV 4400 1000 4200 900 4000 3800 800 3600 2100 27-50keV 50-100keV 2800 2000 1900 2600 Counts per Second 1800 2400 1700 2200 1600 100-290keV 500 290-540keV 1800 1700 1600 400 1500 1400 540-980keV 980-2000keV 600 600 500 500 400 10 5 0 5 10 10 5 0 5 10 Seconds from GW T0 Fig. 5.— De te cte d count rate s summe d ove r NaI de te ctors in 8 e ne rgy channe ls, as a function of time re lative to the start of the GW e ve nt GW150914. Shading highlights the inte rval containing GW150914-GBM. Timebinsare1.024sin duration, with the0.256sCTIME lightcurveove rplotte d ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 66 / 101 in gre e n, and the re d line indicate s the background le ve l.

GW150914 Fermi BGO sums: Connaughton+16 1000 0.11-0.42MeV 800 0.42-0.95MeV 900 700 800 600 700 0.95-2.1MeV 2.1-4.7MeV 900 400 800 Counts per Second 700 300 100 4.7-9.9MeV 9.9-22MeV 50 50 200 22-38MeV 38-50MeV 50 100 10 5 0 5 10 10 5 0 5 10 Seconds from GW T0 Fig. 6.— De te cte d count rate s summe d ove r BGO de te ctors in 8 e ne rgy channe ls, as a function of time re lative to the start of the GW e ve nt GW150914. Shading highlights the inte rval containing GW150914-GBM. Timebinsare1.024sin duration, with the0.256sCTIME lightcurveove rplotte d ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 67 / 101 in gre e n, and the re d line indicate s the background le ve l.

GW150914 Fermi EM counterpart Sky position (Connaughton+16) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 68 / 101

GW150914 observations Swift (Evans+16) No prompt signal, > 50 hours later Auger (Aab+17) No signal Integral SPI ACS (Savchenko+16, (+previus talks) 76000 50 ms 250 ms background 74000 72000 70000 68000 66000 -10 -5 0 5 10 seconds since LVC trigger, UTC 2015-09-14T09:50:45.39 No signal. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 69 / 101

GW150914 Fermi re-analysis Greiner+16: No signal in the Fermi data Simply sum the data from the 14 detectors for energy spectrum! Rhessi BGO data + ADWO: no signal (Ripa+17) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 70 / 101

Fermi GBM detectors 12 NaI(Tl): 8 keV- ∼ 1 MeV, 2 BGO: ∼ 200 keV- ∼ 40 MeV 128 energy channels, 2 µ s time resolution Continous Time Tagged Events (CTTE) since 26/11/2012. Effective area depends on the energy and direction Detector Response Matrix (DRM) transforms the spectrum into counts. Multiple triggers: # of triggered detectors, thresholds (4 . 5 − 7 . 5 σ ) and energy range (25 , 50 , 100 , > 300 keV): ≈ 75 active from the 120. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 71 / 101

Automatized Detector Weight Optimization (ADWO) The approximate trigger time is known: one signal from many detectors and energy channels. Usually: background modell + spectral signal with DRM, fitted with the binned data. But: we do NOT know the direction/DRM! Naïve solution: sum the data. Simple but NOISY! Optimal summing Only the strong signals/detectors/channels should be added. Which ones are important? Non-negative weights: e i for the energy and d j for the detectors ( � e i = 1 , � d j = 1). ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 72 / 101

Signal’s Peak to Background’s Peak Ratio Let C ij ( t ) be a background substracted intensity. The composite signal is: � S ( t ) = e i d j C ij ( t ) i , j S ( t ) : the maximum of the signal within the search interval B ( t ) : the maximum outside the interval. Maximize S ( t ) / B ( t ) , the Signal’s Peak to Background’s Peak Ratio (SPBPR). Nonlinear optimalization. Matlab/Octave code, using fminsearch , (GitHub https://github.com/zbagoly/ADWO ). ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 73 / 101

Analysis of the Fermi data Energy channels e 1 . . . e 8 : 8 CTIME energy channels (128 CTTE channels summed up) According to Connaughton+16, the limits are 4.4, 12, 27, 50, 100, 290, 540, 980 and 2000 keV Low energy channels are quite noisy → Only the 27-2000 keV range ( e 3 . . . e 8 ) are taken No BGO data for e 3 − e 4 : 6 × 14 − 2 × 2 = 80 time series. CTTE Filtering Average ≈ 5 . 8 ms between photons in channels (at GW150914) Smoothing with a 64ms sliding window, 11 . 2 photons in the window. (Q: What is the optimal kernel for an inhomogenous Poisson process?) Total window: ≈ (− 200 , 500 ) s around the event, approx. 1/7 orbit. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 74 / 101

Fermi background fit Szécsi+13: sky sources + geometry + directions with pseudoinverse E.g: GRB091030613 background: 1500 chi2 = 0.973 1400 1300 counts/sec 1200 1100 1000 900 800 -1000 -800 -600 -400 -200 0 200 400 600 800 1000 time Here: short signals only → 6 th order polynome background (like Connaughton+16). ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 75 / 101

GW150914: ADWO (− 195 , 495 ) s window around 14/09/2015 09:50:45 UTC. ADWO: maximum is SPBPR=1.911, 474 ms after the GW trigger (no time constraint for ADWO!). 2.5 2 Signal Peak to Background Peak Ratio 1.5 1 0.5 0 -0.5 -3 -2 -1 0 1 2 3 seconds since 14/09/2015 09:50:45.391 UTC ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 76 / 101

GW150914 Fermi EM counterpart Connaughton+16: ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 77 / 101

GW150914: ADWO significance 10 4 Monte-Carlo (MC) simulation, 86 cases with SPBPR > 1 . 911. 0 . 0014 Hz rate of the error The probability is 2 . 8 × 10 − 3 Hz × 0 . 474 s × ( 1 + ln ( 6 s / 64 ms )) = 0 . 0075. (Connaughton+16: 0.0022) Rhessi BGO data + ADWO: no signal (Ripa+17) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 78 / 101

LVT151012: ADWO (− 195 , 495 ) s window around 02/10/2015 09:54:43.44 UTC ADWO: maximum is SPBPR=1.805, 652 ms later. 2.5 2 Signal Peak to Background Peak Ratio 1.5 1 0.5 0 -0.5 -3 -2 -1 0 1 2 3 seconds since 12/10/2015 09:54:43.555 UTC ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 79 / 101

LVT151012 ADWO significance 10 4 Monte-Ca/lo (MC) simulations, 308 cases with SPBPR > 1 . 805. Error rate is 0 . 0051 Hz. The probability is 0 . 01 Hz × 0 . 652 s × ( 1 + ln ( 6 s / 64 ms )) = 0 . 037. No lighning/TGF. Fermi group (Racusin+16) No signal was detected ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 80 / 101

GW150914: investigation of the daily background Fermi: no signal 61.4 ks CTTE data, same day, no re-pointing, 6s window. 1 0.9 0.8 0.7 GRB150522B softness (e 3 +e 4 +e 5 ) 0.6 0.5 LVT151012 0.4 GW150914 0.3 0.2 0.1 0 1 2 3 4 5 6 Signal Peak to Background Peak Ratio ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 81 / 101

GW121226; ADWO Triggered on 26/12/2015 03:38:53.647 UTC. ADWO: maximum is SPBPR=1.321, probably noise. 0.04 0.03 0.02 ADWO lightcurve 0.01 0 -0.01 -0.02 -30 -20 -10 0 10 20 30 40 50 60 seconds since GW121226 ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 82 / 101

GW121226; ADWO Triggered on 26/12/2015 03:38:53.647 UTC. ADWO: maximum is SPBPR=1.321, probably noise. 1.4 1.2 Signal Peak to Background Peak Ratio 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -3 -2 -1 0 1 2 3 Seconds since 26/12/2015 03:38:53.647 UTC ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 82 / 101

GW121226 Fermi group (Racusin+16) No signal detected Auger (Aab+17) No signal ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 83 / 101

GW170104: Fermi (Burns+17,Fermi collaboration+17) Good GBM exposure ( ≈ 82 . 4 % ) : GBM upper limit: ( 5 . 2 − 9 . 4 ) × 10 − 7 erg cm − 2 s − 1 (10-1000 keV) LAT upper limit: ( 0 . 2 − 13 ) × 10 − 9 erg cm − 2 s − 1 (0.1-1 GeV) GBM most significant candidate: 5.4 s before the T 0 , false alarm rate of ≈ 0 . 003 Hz. Longer term structure for tens of seconds in the low energy channels around T 0 . ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 84 / 101

GW170104 EM observations: AGILE (Verrecchia+17) Good exposure ( ≈ 36%) around T 0 : SA detector No gamma-ray transient near T 0 over timescales of 2, 20 and 200 seconds. Upper limit: ( 1 . 5 − 6 . 6 ) × 10 − 8 erg cm − 2 (depending on the direction) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 85 / 101

GW170104 EM observations: AGILE MCAL detector 3 short timescale events/features E2: strongest at T = − 0 . 46 s , above 1.4 MeV E2 event’s post-trial probability is 3 . 4 σ If real, total energy is 10 − 7 smaller than the total black hole rest mass! ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 86 / 101

GW170104: ADWO GBM data: (− 200 , 140 ) s interval around 04/01/2017 10:11:58.599 UTC. ADWO: maximum is SPBPR=1.51, at T ≈ − 50ms, in the noise. AstroSat-CZTI and GROWTH (Bhalerao+17) CZTI upper limit: ≈ 4 . 5 × 10 − 7 erg cm − 2 s − 1 for a 1 s timescale ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 87 / 101

Fast Radio Bursts (preliminary) FRB121102 repeating source, Chatterjee+17 8 ADWO period, good seeing, multiple SPBPR, Max. SPBPR= ≈ 1 . 81, at the limit, probably noise. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 88 / 101

GW170814: ADWO GBM data: (− 50 , 250 ) s interval (particle event at ≈ − 50s) ADWO: maximum is SPBPR=1.28, in the noise. ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 89 / 101

GW170817A: ADWO GBM data: (− 100 , 100 ) s interval (SAA entry) ADWO: maximum is SPBPR=2.6902, strong signal! 3 2.5 2 1.5 SPBPR 1 0.5 0 -0.5 -1 -10 -5 0 5 10 t (since GRB170817A trigger) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 90 / 101

GW170817A Fermi (Goldstein, Veres +17) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 91 / 101

GRB groups and the GRB170817A/GW170817 1.0� short� intermediate� 0.8� long� GRB 170817A� 0.6� 0.4� lg Spectral Hardness� 0.2� 0.0� -0.2� -0.4� -0.6� -0.8� -1.0� -1� 0� 1� 2� 3� lg T90� GRB170817A/GW170817 in the intermediate group! ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 92 / 101

ADWO Summary Efficient method looking for transients (GRB, GW, FRB, IceCUBE (no counterparts), . . . ) Method impovements optimal smoothing filter/kernel optimalized energy channels, DRM constraints direction determination (huge errors?) multi-messenger data Other transients (s)GRBs, non-triggered (s)GRBs, non-triggered GW ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 93 / 101

ADWO efficiency 1 0.9 0.8 GRB150921153 GRB170817A GRB150522B 0.7 GW170814 softness (e 3 +e 4 +e 5 ) 0.6 GW121226 0.5 LVT151012 GW170104 0.4 GRB160301788 GW150914 0.3 0.2 0.1 0 1 2 3 4 5 6 Signal Peak to Background Peak Ratio Red: 61.4 ks good CTTE data (14/09/2015) („background”?!) Blue: Fermi’s (s)GRB triggers, T90<15s ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 94 / 101

Fermi (s)GRB Supergalactic Distribution Short (T90<5s) GRBs with ADWO hard (SR<0.4) peak spectrum, no measured redshift ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 95 / 101

Future Missions: SVOM Cordier+18 ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 96 / 101

Future Missions: Theseus ESA M5 proposal ≈ 2028, 400M EUR budget IR, X-ray and gamma detectors high-z magas events (optical + HE) ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 97 / 101

Theseus Star Formation Rate Amati+18 ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 98 / 101

Theseus Redshifts Amati+18 ELFT Summer School’18 Gamma-ray bursts in the era of multi-messenger astronomy 99 / 101