prompt emission properties of x-ray flashes and gamma-ray bursts
DESCRIPTION
Prompt Emission Properties of X-ray Flashes and Gamma-ray Bursts. T. Sakamoto (CRESST/UMBC/GSFC). Contents. First BAT GRB catalog X-ray Flashes (XRFs) Prompt emission properties of XRFs (BATSE/BeppoSAX/HETE-2/Swift)? (4. X-ray flares) (5. X-ray afterglows of XRFs). - PowerPoint PPT PresentationTRANSCRIPT
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Prompt Emission Properties of Prompt Emission Properties of X-ray Flashes and Gamma-ray BurstsX-ray Flashes and Gamma-ray Bursts
T. Sakamoto (CRESST/UMBC/GSFC)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
ContentsContents
1. First BAT GRB catalog2. X-ray Flashes (XRFs)3. Prompt emission properties of XRFs (BATSE/BeppoSAX/HETE-2/Swift)?(4. X-ray flares)(5. X-ray afterglows of XRFs)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
First BAT GRB catalogFirst BAT GRB catalog(BAT1 catalog)(BAT1 catalog)
Sakamoto et al. ApJS, 175, 179Sakamoto et al. ApJS, 175, 179
2008. 6. 25. 2008 Nanjing GRB Conference Swift
BAT GRB sky mapBAT GRB sky map
- 237 GRBs (from GRB 041217 to GRB 070616)- BAT event-by-event data analysis
Galactic coordinate
2008. 6. 25. 2008 Nanjing GRB Conference Swift
TT9090/T/T5050 (mask-weighted 15-350 keV) (mask-weighted 15-350 keV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Hardness – THardness – T9090
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Time-averaged spectrum (PL fit)Time-averaged spectrum (PL fit)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
PL photon index vs. P(15-150 keV)PL photon index vs. P(15-150 keV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Summary (I)Summary (I)
BAT is fine. Detecting/localizing ~100 GRBs/yr. Watching for z>7 and z<0.1 GRBs. Watching for the next naked eye burst.
2008. 6. 25. 2008 Nanjing GRB Conference Swift
X-ray Flashes (XRFs)X-ray Flashes (XRFs)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
X-ray band
ray band
X-ray flash (XRF)Classical gamma-ray burst (C-GRB)
(Heise et al. 2001) (in’t Zand et al. 1999)
X-ray flashes and classical (long) GRBs : BeppoSAX/BATSE
2008. 6. 25. 2008 Nanjing GRB Conference Swift
XRF 010213 GRB 030725
X-ray flashes and classical (long) GRBs : HETE-2
2008. 6. 25. 2008 Nanjing GRB Conference Swift
GRB 050401XRF 050416A
X-ray flashes and classical (long) GRBs: Swift BAT
2008. 6. 25. 2008 Nanjing GRB Conference Swift
““X-ray Flashes”X-ray Flashes”
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Empirical spectral models of GRBsEmpirical spectral models of GRBs
Eexp (E/E0)
E
E0 = Epeak / (2 + )
Ebreak = (E0
Band function
dN/dE
Energy
(Band et al. 1993)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Spectral parameters of GRBs (BATSE) Spectral parameters of GRBs (BATSE)
Band function
Ep
3 2 1 0 1
200
150
100
50
01 2 3 4
log Ep [keV] (~ 2.5)
150
100
50
0
(BATSE spectral catalog, Preece et at. 2000)
Energy
F
E
Ep
E
200 – 300 keV
2008. 6. 25. 2008 Nanjing GRB Conference Swift
X-Ray Flashes (XRFs) and X-ray rich GRBsX-Ray Flashes (XRFs) and X-ray rich GRBs(Ginga and BeppoSAX WFC)(Ginga and BeppoSAX WFC)
Ginga (Strohmayer et al. 1998)
1 0 1 2
1 2 3 4 log Ep [keV]
0
1
2
3
4
0
2
4
Nu
mb
er o
f ev
ents
BATSE
BATSE
WFC / BATSE (Kippen et al. 2002)
(22 GRBs)
10
100
1000
Ep (
keV
)
Peak Flux P1024 (ph cm-2 s-1)
XRFs: Systematically low Epeak
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Prompt emission properties of XRFsPrompt emission properties of XRFs
2008. 6. 25. 2008 Nanjing GRB Conference Swift
ObjectiveObjective
GRBs
Classify
XRFs XRRs C-GRBs
(X-ray flashes) (X-ray-rich GRBs) (Classical GRBs)
Spectral hardness
XRFs
XRRs
C-GRBs
XRFs
XRRs
C-GRBs
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Classification of GRBsClassification of GRBs
(Fluence in 2-30 keV : SX, Fluence in 30-400 keV : S
log (SX / S) > 00.5 < log (SX / S) ≤ 0
log (SX / S) ≤ 0.5
XRFXRRC-GRB
(Sakamoto et al. 2005)
HETE-2
BeppoSAX “XRFs: Detected by Wide Field Camera (WFC), but not by Gamma-Ray Burst Monitor (GRBM)”
Swift/BAT ?
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeak vs. fluence ratio vs. fluence ratio
1 10 100 1000Epeak (keV)
0.1
1
10
SX /
S
XRF
XRR
C-GRB
HETE GRB sample
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Classification of GRBsClassification of GRBs
(Fluence in 2-30 keV : SX, Fluence in 30-400 keV : S
log (SX / S) > 00.5 < log (SX / S) ≤ 0
log (SX / S) ≤ 0.5
XRFXRRC-GRB
(Sakamoto et al. 2005)
HETE-2
BeppoSAX “XRFs: Detected by Wide Field Camera (WFC), but not by Gamma-ray burst monitor (GRBM)”
Swift/BAT
Ep=30 keV
Ep=100 keV(Sakamoto et al. 2008)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
GRB sampleGRB sample
BATSE (Kaneko et al. 2006) - Time-averaged best fit spectral parameters by BAND and COMP fit
0 XRF181 GRB 26 XRR 155 C-GRB
Total 568 GRBs (342 GRBs)
BeppoSAX (D’Alessio et al. 2006, Amati et al. 2002) - Only Ep information
7 XRF 24 GRB 11 XRR 6 C-GRB
HETE-2 (Sakamoto et al. 2005; Pelangeon et al. submitted A&A)
26 XRF 84 GRB 33 XRR 25 C-GRB
Swift/BAT (Sakamoto et al. 2008+); 17 XRF279 GRB 179 XRR 83 C-GRB
Swift/BAT with Ep (Sakamoto et al. 2008+); 17 XRF 53 GRB 22 XRR 14 C-GRB
2008. 6. 25. 2008 Nanjing GRB Conference Swift
List of XRFs I (BeppoSAX/HETE-2/Swift)List of XRFs I (BeppoSAX/HETE-2/Swift)
XRF Mission Epeakobs [keV] AG z
971019 SAX 19 +/- 1 - -990520 SAX 26 +/- 3 X -990526 SAX 15 +/-14 - -990704 SAX 9 (-7/+50) X -000206 SAX 38 +/- 5 - -000416 SAX 1.6 +/- 6.6 - -010213 HETE-2 3.4 +- 0.4 - -010225 HETE-2 32 (+27/-9) - -011019 HETE-2 19 (+18/-9) - -011130 HETE-2 < 4 - -011212 HETE-2 NA - -020317 HETE-2 28 (+13/-7) - -020427 SAX 3 +/- 3 X -020625 HETE-2 9 (+5/-3) - -020903 HETE-2 3 +/- 1 O,R 0.25021021 HETE-2 15 (+14/-7) - -021104 HETE-2 28 (+17/-8) - -
XRF Mission Epeakobs [keV] AG z
030416 HETE-2 3 (+1/-2) - -030429 HETE-2 35 (+12/-8) O 2.65030528 HETE-2 32 +/- 5 X,O 0.782030723 HETE-2 < 8.9 X,O -030823 HETE-2 27 (+7/-5) - - 030824 HETE-2 6.1 (+2/-4) - -031109B HETE-2 38 (+28/-12) - -031111B HETE-2 6 (+4/-5) - -040423 HETE-2 30 (+5/-4) - -040701 HETE-2 < 3.4 X -040825B HETE-2 25 (+16/-8) - -040912A HETE-2 14 (+3/-4) - -040912B HETE-2 17 (+13/-13) X 1.563040916 HETE-2 < 3.5 O -050406 Swift 29 (+7/-12) X,O 050408 HETE-2 26 (+11/-7) X,O 1.2357050416A Swift 17 (+6/-10) X,O,R 0.6535
2008. 6. 25. 2008 Nanjing GRB Conference Swift
List of XRFs II List of XRFs II (BeppoSAX/HETE-2/Swift)(BeppoSAX/HETE-2/Swift)
XRF Mission Epeakobs [keV] AG z
050509 HETE-2 < 19 - - 050714B Swift 27 (+7/-18) X -050819 Swift 22 (+6/-17) X -050824 Swift < 19 X,O 0.83060218 Swift 4.7 (-0.3/+0.4) X,O,R 0.0331060219 Swift < 33 X - 060428B Swift 23 (+5/-12) X,O -060512 Swift 23 (+8/-18) X,O 0.4428060923B Swift < 27.6 X -060926 Swift < 23 X,O 3.20061218 Swift 19 (+11/-8) - -070224 Swift < 35 X,O -070714A Swift < 20 X -070721A Swift < 30 X,O -080218B Swift 20 (+5/-6) - -080330 Swift < 24 X,O 1.51080515 Swift 24 (+5/-5) X,O -
Total: 51 XRFsXA : 24 XRFsOA : 17 XRFs z : 11 XRFs
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Histogram of log[S(2-30 keV)/S(30-400 keV)]Histogram of log[S(2-30 keV)/S(30-400 keV)]
C-GRBs XRR XRF
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Histogram of S(25-50 keV)/S(50-100 keV)Histogram of S(25-50 keV)/S(50-100 keV)
C-GRBs XRR XRF
Broad continuum in the fluence distribution
2008. 6. 25. 2008 Nanjing GRB Conference Swift
S(2-30 keV) vs. S(30-400 keV)S(2-30 keV) vs. S(30-400 keV)
C-GRBs/XRR
XRR/XRF
2008. 6. 25. 2008 Nanjing GRB Conference Swift
S(2-30 keV) vs. S(30-400 keV)S(2-30 keV) vs. S(30-400 keV)
C-GRBs/XRR
XRR/XRF
2008. 6. 25. 2008 Nanjing GRB Conference Swift
S(25-50 keV) vs. S(50-100 keV)S(25-50 keV) vs. S(50-100 keV)
C-GRBs/XRR
XRR/XRF
2008. 6. 25. 2008 Nanjing GRB Conference Swift
S(25-50 keV) vs. S(50-100 keV)S(25-50 keV) vs. S(50-100 keV)
C-GRBs/XRR
XRR/XRF
2008. 6. 25. 2008 Nanjing GRB Conference Swift
S(25-50 keV) vs. S(50-100 keV)S(25-50 keV) vs. S(50-100 keV)
C-GRBs/XRR
XRR/XRF
Single distribution in the fluence-fluence plane
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Histogram of EHistogram of Epeakpeakobsobs
Broad Epeakobs distribution
(from a few keV to a few MeV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. alpha vs. alpha
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. alpha vs. alpha
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. alpha vs. alpha
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. alpha vs. alpha
alpha ~ -1 for all GRBs
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. beta vs. beta
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. beta vs. beta
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. beta vs. beta
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. beta vs. beta
beta ~ -2.5 for all GRBs
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. S(2-400 keV) vs. S(2-400 keV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. S(2-400 keV) vs. S(2-400 keV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. S(15-150 keV) vs. S(15-150 keV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. S(15-150 keV) vs. S(15-150 keV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeakobsobs vs. S(15-150 keV) vs. S(15-150 keV)
Positive correlation between Epeak
obs and the fluence
Epeakobs ~ S 0.5
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Redshift distributionsRedshift distributions
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeaksrcsrc distribution distribution
Broad Epeaksrc distribution
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeak-E-Eisoiso relation relation
Epeaksrc = 95 keV (Eiso/1052 ergs)0.5
(Amati 2006)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Re-classify XRFs at the rest frameRe-classify XRFs at the rest frame
XRF z Epeakobs Epeak
src Re-classification
020930 0.25 2.6 3.3 XRF030429 2.65 35 128 C-GRBs030528 0.782 32 57 XRR040912B 1.563 17 44 XRR050408 1.236 26 58 XRR050416A 0.654 17 28 XRF050824 0.83 <19 <34 XRF/XRR060218 0.0331 4.7 4.9 XRF060512 0.443 23 33 XRR060926 3.20 <23 <97 XRR080330 1.51 <24 <60 XRR
Only three XRFs cab be classified as XRF at the rest frame.
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Summary (II)Summary (II)
XRFs, XRRs, and GRBs form a continuum (BATSE/BeppoSAX/HETE-2/Swift).
Epeakobs is broadly distributed from a few keV to a f
ew MeV (same for Epeaksrc).
The redshift distribution of XRFs could be systematically lower than C-GRBs.
We only have three samples of intrinsic XRFs.
C-GRB
XRR
XRF
E-1
E-2.5
Epeak
2008. 6. 25. 2008 Nanjing GRB Conference Swift
X-ray FlaresX-ray Flares
2008. 6. 25. 2008 Nanjing GRB Conference Swift
X-ray Flare: Prompt X-ray emissionX-ray Flare: Prompt X-ray emissionGRB 720427 (Metzger et al, 1974)
(Apollo 16 and Vela 6A)GRB 030725
2008. 6. 25. 2008 Nanjing GRB Conference Swift
GRB 080607 X-ray flareGRB 080607 X-ray flareC
ount
s/se
c/de
tC
ount
s/se
cC
ount
s/se
c/w
ire
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Late-time X-ray flares are unique…Late-time X-ray flares are unique…
(Watson et al. 2005)
X-ray flares T0 > 1000 s
Very unique Swift/XRT observations
However…
X-ray flares T0 < 1000 s
Same prompt X-ray emission observed by
previous missions (e.g. HETE-2/WXM)
GRB 050904
2008. 6. 25. 2008 Nanjing GRB Conference Swift
X-ray afterglows of XRFsX-ray afterglows of XRFs
(Sakamoto et al. 2008, ApJ, 679, 570)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
XRF X-ray afterglowXRF X-ray afterglow
2008. 6. 25. 2008 Nanjing GRB Conference Swift
C-GRB X-ray afterglowC-GRB X-ray afterglow
2008. 6. 25. 2008 Nanjing GRB Conference Swift
X-ray light curve at the rest-frameX-ray light curve at the rest-frame
Epeaksrc < 100 keV
100 keV < Epeaksrc < 300 keV
Epeaksrc > 300 keV
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Fx
Time [s]
t –0.5 – t –1.0
t-1.0 – t-2.0
t-1 C-GRB
XRF
103-104 sec
C-GRB:Break around 103-104 sec
XRF:Simple decay with the index of -1Flux is systematically lower
Must be telling something…Must be telling something…
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Summary (III)Summary (III)
XRFs, XRRs, and GRBs form a continuum (BATSE/BeppoSAX/HETE-2/Swift).
Epeakobs is broadly distributed from a few keV to a fe
w MeV (same for Epeaksrc).
The redshift distribution of XRFs could be systematically lower than C-GRBs.
We only have three samples of intrinsic XRFs. Clear definition in “X-ray flare” is needed. Distinct difference in X-ray afterglows between XR
Fs and C-GRBs.
2008. 6. 25. 2008 Nanjing GRB Conference Swift
2008. 6. 25. 2008 Nanjing GRB Conference Swift
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeak vs. Energy Flux vs. Energy Flux
Number of simulated spectra Band – PL) > 6
BAT 15-150 keV
Epeak measurement with BAT: > ~ 2 x 10-8 ergs/cm2/s (log F(15-150) = -7.7)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeak-Gamma relation-Gamma relation
2008. 6. 25. 2008 Nanjing GRB Conference Swift
EEpeakpeak-Gamma relation-Gamma relation
2008. 6. 25. 2008 Nanjing GRB Conference Swift
BAT (81 GRBs)BATSE
BAT TBAT T9090 vs. Hardness vs. Hardness
2008. 6. 25. 2008 Nanjing GRB Conference Swift
GRB 020531
GRB 050709
Sakamoto et al.Villasenor et al.
HETE (46 GRBs)BATSE
HETE THETE T9090 vs. Hardness vs. Hardness
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Konus-Wind TKonus-Wind T9090 vs. Hardness vs. HardnessMazets et al. : short GRBsV. Pal’shin : long GRBs
Konus-Wind (125 GRBs)BATSE
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Konus-Wind Histograms of HardnessKonus-Wind Histograms of Hardnesslong GRBs(T90 ≧ 2 sec.)
Short GRBs(T90 < 2 sec.)
HR 6: 10% short GRBs (46% BATSE)≧HR 8: 0% short GRBs (26% BATSE)≧
S(100-300 keV) / S(50-100 keV)
Nu
mb
er o
f G
RB
s
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Histogram of Hardness - Short GRBs -Histogram of Hardness - Short GRBs -
S(100-300 keV) / S(50-100 keV)
Nu
mb
er o
f G
RB
s
BAT
HETE
BATSE
Konus-Wind
2008. 6. 25. 2008 Nanjing GRB Conference Swift
vs. Evs. E00
E0 [
keV
]
4-6 6-8 8-10
Hardness =S(100-300 keV)
S(50-100 keV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
S(2-30 keV) vs. S(30-400 keV)S(2-30 keV) vs. S(30-400 keV)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
““Short XRFs” in the Swift sample?Short XRFs” in the Swift sample?
2008. 6. 25. 2008 Nanjing GRB Conference Swift
““Short XRFs” in the Swift sample?Short XRFs” in the Swift sample?
2008. 6. 25. 2008 Nanjing GRB Conference Swift
““Short XRFs” in the Swift sample?Short XRFs” in the Swift sample?
2008. 6. 25. 2008 Nanjing GRB Conference Swift
““Short XRFs” in the Swift sample?Short XRFs” in the Swift sample?
2008. 6. 25. 2008 Nanjing GRB Conference Swift
How to make short XRF with BAT?How to make short XRF with BAT?dN/dE
E
E-1
E-2.3
Ep
Flu
x (1
5-15
0 ke
V)
Input light curveEp = 50 keV
Ep = 50 keV
Ep = 30 keV
Ep = 20 keV
Cou
nt r
ate
[c/s
]
- BAT energy response (30 deg)- background included- Xspec fakeit
“Shortness” of BAT XRF is very likely due to the
instrumental effect.
2008. 6. 25. 2008 Nanjing GRB Conference Swift
XRFXRRC-GRB
Energy spectrum of XRFsEnergy spectrum of XRFs
1 10 100 1000Energy (keV)
102
1
102
104
F
(
keV
cm
2 s
1)
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Discussion (1)Discussion (1)
Two categories in the luminosity evolution in the optical light curves (Liang & Zhang).
<Epeaksrc > = 96 keV for the dim group
< Epeaksrc> = 543 keV for the bright group
(ref Amati 2006)
Consistent with the X-ray luminosity light curves
Understanding Shallow-to-normal break in the geometrical jet model.
2008. 6. 25. 2008 Nanjing GRB Conference Swift
Discussion (2)Discussion (2)
Shallow-to-normal break Epeak
Thick ring jet model