最新2019-GRBs detected by INTEGRAL检测到的积分暴-PPT课件

Coded Mask
Germanium Detector Array
IBIS – Imager on Board the INTEGRAL Satellite
Coded Mask
ISGRI PICsIT
• Full imaging capability - FWHM ~12’ • Fully coded field of view 9° x 9° • ISGRI – energy range 20 keV – 1 MeV – 128 x 128 CdTe pixels • Moderate energy resolution • PICsIT – energy range 200 keV – 10 MeV – 64 x 64 CsI pixels
19 detectors
240°
300°
180°
0°
120°
60°
Polarisation of GRB 041219A
S. McGlynn Poster Session “Polarisation Properties of GRB041219a”
• Can compare real data to simulated polarised and unpolarised data to obtain polarisation fraction • Q (modulation factor) is the maximum variation in azimuthal scattering probability for polarised photons
• Peak of cross-correlation function (CCF) corresponds to spectral lag of the GRB
• Lag-luminosity relationship Norris et al. ApJ, 2019 => Can use spectral lag as RB 041219A – contd.
Precursor
S. McBreen Poster Session “ Broadband spectrum Of GRB041219a”
keV (keV cm-2 s-1 keV-1)
Pulse 1
Pulse 2
• Spectrum of burst and subintervals well fit by Band model • Also fit well by black body + power law model
JEM-X masks IBIS mask Optical Monitor
IBIS detector
JEM-X detectors
SPI
SPI – SPectrometer on INTEGRAL
• 19 Ge detector array • energy range of 15 keV to 8 MeV • high energy resolution – ~2 keV at 1 MeV • fully coded field of view 16° corner to corner • limited imaging capability
60 40 130 25 20 80 100 40 78
Peak flux (20-200 keV) (photons cm-2s-1)
0.3
0.2
0.7
0.1 0.4 0.6 0.3 0.2 0.2
Power law photon index
2.2 ± 0.2 2.2 ± 0.2
N/A N/A 1.9 ± 0.2 1.7 ± 0.1 1.1 ± 0.2 1.8 ± 0.4 1.6 ± 0.3
谢谢！
• T90 = 186s – greater than all but a handful of BATSE bursts
• Unusual time structure - very little emission for ~200s before pulse 1 starts
• Emission detected up to a few MeV
• 050525a : z = 0.606 • 050502a : z = 3.79 • 031203 : z = 0.106
GRB 031203 Sazonov et al. ,2019
• Single peaked burst, duration ~ 30s • z = 0.106, 3rd nearest GRB • Associated with Type Ic supernova
• Ground-based IBAS localisations based on IBIS data – large field of view, high angular resolution
• ~ 1 GRB/month localised with ~3’ error radius
Spatial Distribution in Galactic Coordinates
Afterglows X=Xray O=optical
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X, O?
X
X, O -
INTEGRAL/SWIFT Peak Flux Distribution
Conclusions:
• IBAS provides accurate, fast localisations to the GRB community - ~1 GRB per month
• IBIS multi-band lightcurves allow for spectral lag (and luminosity) measurements to be made
• SWIFT detects more GRBs due to its larger field of view, however INTEGRAL detects many bursts at lower peak fluxes
IBAS – Integral Burst Alert System
ibas.mi.iasfr.it • Automatic system for the rapid distribution of GRB coordinates
• INTEGRAL’s 72-hour highly eccentric orbit allows for almost continuous data transmission to ground
Recent GRBs detected by INTEGRAL
GRB
GRB 050626 GRB 050714A GRB 050918 GRB 050922A GRB 051105B GRB 051211B GRB 060114 GRB 060130 GRB 060204A
Duration (s)
Spectral Lag – Cross Correlation Analysis
• Observed GRB phenomenon – time delay between arrival of high and low energy photons
• Cross-correlation analysis determines variable parameter between two similar signals, i.e., temporal lag between two lightcurves in different energy bands
GRB 040624 Filliatre et al. A&A, 2019
• One of the weakest GRBs detected by INTEGRAL • Weak, long, slow pulse - T90 = 46s • Steep power law fit to spectrum implies X-ray rich GRB • Optical follow-up - “dark” burst – no detected optical afterglow
• INTEGRAL is providing new and interesting results on GRB prompt emission and enabling rapid afterglow follow-ups to be carried out
• INTEGRAL’s SPI instrument may be used to detect polarisation in GRBs
GRB 040624 – Spectral Lag
GRB 040624 time profiles in 25-50 keV band (blue) and 50-300 keV band (red)
CCF peak at a spectral lag, τ of -2.3 ± 0.5 s (high energy preceding low energy)
• Took all double events with total energy deposit 100<Etot<500keV and summed in 6 directions • Fit cos function to scatter - using Q and modulation of cos function produces polarisation of 116 ± 47 %
• 37 GRBs localised by IBAS to date • Distribution concentrated in direction of Galactic plane corresponding to maximum exposure time
Spectroscopic Redshifts
Gamma-Ray Bursts Detected by INTEGRAL
S. Foley, L. Hanlon, S. McBreen, S. McGlynn, B. McBreen School of Physics University College Dublin
INTEGRAL Instruments
• Inferred high soft X-ray flux implies X-Ray Flash
GRB 041219A McBreen et al. A&A, 2019
• Peak flux 43 ph cm-2 s-1 – greater than ~ 98% of BATSE bursts
GRB 031203 – contd.
Vaughan et al. 2019
• XMM follow-up - observed concentric ring-like structures centred on GRB location – first detection of GRB X-ray “halo”
Ryde, ApJ, 2019
• Black body contributes more strongly in precursor than pulses 1 and 2
Polarisation with SPI
SPI can measure polarisation through multiple events in its