Gamma Ray Burst Overview

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UVOT
Gamma Ray Burst Overview
Neil Gehrels NASA-GSFC
MIT GWDA Workshop December 13, 2007
XRT
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OUTLINE
Swift Observatory
? Short long GRBs ? Short GRB afterglow
hosts ? Beaming energetics ? Hot
topics ? Implications for GW detection ?
Future prospects
.
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A Brief History of Time
First hints of 2 duration classes Cline Desai
1974 Mazets 1981 Two classes seen in ISEE-3
Konus data Norris et al. 1984 Definite proof
with large statistics from BATSE Kouveliotou et
al. 1993
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Long GRBs
GRB 990123 - HST
Energy 1051 ergs in g-rays (5 beams)
1051 ergs in afterglow 1052 ergs in
outflow Distance ltzgt2.3 (Swift average - long
GRBs) 11 Gyr light travel time Jet
Outflow highly relativistic (G gt
100) Variability msec time structure in prompt
burst Power source gravitational infall on
new-born BHs
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GRB 050505
z 4.27 Duration 60 s
Bright afterglows
Hurkett et al. 2005
Savaglio 2006
Berger et al. 2005
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GRB 050904
6.29
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GRB 060218 GRB Supernova
Super-long GRB 35 minutes BAT, XRT,
UVOT during GRB z 0.033 d 145 Mpc
SN 2006aj SN Ib/c hypernova Eiso few x
1049 erg - underluminous
Campana et al., Mazzali et al., Pian et al.,
Soderberg et al.
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Short GRBs
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Comparing Short and Long GRBs
Norris et al. 2006
GRB 061121 brightest long GRB GRB 061210
brightest short GRB
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Comparing Short and Long GRBs
BATSE
Swift Short GRB 051221A
Horváth 2002
GRB 061121 brightest long GRB GRB 061210
brightest short GRB
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Short vs Long GRBs
GRB
In SF galaxies Accompanied by SNe Collapsar
model well supported
In non-SF and SF galaxies No SNe
detected Possible merger model
BH
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GRB 050509B
BAT - 30 millisecond duration Spacecraft
slew in 52 sec XRT - faint source, fading -
11 cnts Host - cD elliptical (L 3 L) - SFR
lt 0.2 MO yr-1 - z 0.225 (817 Mpc) No
supernova to deep limits
VLT image Hjorth et al. 2005
N.G. et al. 2005
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HETE-2 GRB 050709
GRB 050724
Villasenor et al.
Fox et al.
Barthelmy et al.
- z 0.161 (609 Mpc) - SF galaxy but in
dark region - XT - XRT, Chandra - OT -
ground-based, HST - No supernova to deep limits
GRB 050724
- z 0.258 (918 Mpc) - Elliptical - SFR
lt 0.02 MO yr-1 - X, optical radio
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Long GRBs
Short GRBs
cD elliptical
SFR lt 0.2 MO yr-1
050709
SF galaxy with offset
SF irregulars (Fruchter et al.)
050724
elliptical
SFR lt 0.02 MO yr-1
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Short GRB - Current Status
Swift short GRB observations - 29 short
bursts detected ( 2 from HETE, 1 from
INTEGRAL) - 18 with X-ray afterglow detected by
XRT - 9 with optical detection - 7 with
firm host galaxies and redshifts 20 Swift
and BATSE short GRBs accompanied by soft
extended emission up to 100 sec
Redshift range from z 0.2 to 1 - ltzgtshort
0.4 - ltzgtlong 2.3 GRB 070429B z
0.90 (Graham et al. 2007) GRB 070714B z
0.92 (Graham et al. 2007)
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Short GRB - Current Status
Swift short GRB observations - 29 short
bursts detected ( 2 from HETE, 1 from
INTEGRAL) - 18 with X-ray afterglow detected by
XRT - 9 with optical detection - 7 with
firm host galaxies and redshifts 20 Swift
and BATSE short GRBs accompanied by soft
extended emission up to 100 sec
Redshift range from z 0.2 to 1 - ltzgtshort
0.4 - ltzgtlong 2.3 GRB 070429B z
0.90 (Graham et al. 2007) GRB 070714B z
0.92 (Graham et al. 2007)
Swift detects 10 short GRBs BATSE detected 25
short GRBs Swift misses some short GRBs due
to observing at lower energies and requiring
image Best full-sky short GRB rate is from
BATSE 250 yr-1
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Name Redshift Afteglow
Host Duration
Extended Comment
z
(s)
Emission? ____________________________________
__________________________________________________
_______________________________________
050509B 0.225 X elliptical 0.03 N low SF rate
elliptical 050709 0.161 X, O galaxy 0.07
(150) Y SR galaxy in low SF region
050724 0.258 X, O, R elliptical 3.0 (120) Y low
SF rate elliptical 050813 1.8 ? X ?
galaxies, cluster 0.60 N - 050906 - -
- 0.13 N - 051103 2.6 Mpc ? - near
M81/M82 - - extragalactic SGR? 051105A - - -
0.03 N - 051210 0.114? X ? cluster 1.4 N -
051221A 0.547 X, O, R galaxy 1.4 N SF galaxy
051227 - X, O faint galaxy 0.9 (16) Y -
060121 gt1.5 X, O ? galaxies 2.0 N -
060313 - X, O ? cluster 0.7 N -
060502B 0.287? X elliptical _at_50kpc 0.09 N -
060801 1.131? X ? galaxies 0.5 N - 061006 - X,
O - 0.5 (130) Y - 061201 0.111? X, O ? galaxy
_at_34kpc 0.8 N - 061210 0.41? X ? galaxies 0.19
(85) Y - 061217 0.827? X ? galaxies 0.3 N -
070201 0.7 Mpc ? - near M31 - - extragalactic
SGR? 070209 - - - 0.1 N - 070406 - - - 0.7 N -
070429B 0.904 X, O galaxy 0.5 N UVOT
detection 070707 - X, O - 1.0 N -
070714B 0.92 X, O galaxy 2.9 (64) Y R25.5 host
070724 0.457 X galaxy 0.4 N SF galaxy
070729 - X - 0.9 N - 070809 - X, O - 1.3 N -
070810B - - - 0.08 N - 070923 - - - 0.05 N -
071112B - - - 0.3 N -
HETE
IPN
INTEGRAL
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Name Redshift Afteglow
Host Duration
Extended Comment
z
(s)
Emission? _____________________________________
__________________________________________________
______________________________________
050509B 0.225 X elliptical 0.03 N low SF rate
elliptical 050709 0.161 X, O galaxy 0.07
(150) Y SR galaxy in low SF region
050724 0.258 X, O, R elliptical 3.0 (120) Y low
SF rate elliptical 050813 1.8 ? X ?
galaxies, cluster 0.60 N - 050906 - -
- 0.13 N - 051103 2.6 Mpc ? - near
M81/M82 - - extragalactic SGR? 051105A - - -
0.03 N - 051210 0.114? X ? cluster 1.4 N -
051221A 0.547 X, O, R galaxy 1.4 N SF galaxy
051227 - X, O faint galaxy 0.9 (16) Y -
060121 gt1.5 X, O ? galaxies 2.0 N -
060313 - X, O ? cluster 0.7 N -
060502B 0.287? X elliptical _at_50kpc 0.09 N -
060801 1.131? X ? galaxies 0.5 N - 061006 - X,
O - 0.5 (130) Y - 061201 0.111? X, O ? galaxy
_at_34kpc 0.8 N - 061210 0.41? X ? galaxies 0.19
(85) Y - 061217 0.827? X ? galaxies 0.3 N -
070201 0.7 Mpc ? - near M31 - - extragalactic
SGR? 070209 - - - 0.1 N - 070406 - - - 0.7 N -
070429B 0.904 X, O galaxy 0.5 N UVOT
detection 070707 - X, O - 1.0 N -
070714B 0.92 X, O galaxy 2.9 (64) Y R25.5 host
070724 0.457 X galaxy 0.4 N SF galaxy
070729 - X - 0.9 N - 070809 - X, O - 1.3 N -
070810B - - - 0.08 N - 070923 - - - 0.05 N -
071112B - - - 0.3 N -
HETE
IPN
INTEGRAL
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Name Redshift Afteglow
Host Duration
Extended Comment
z
(s)
Emission? _____________________________________
__________________________________________________
______________________________________
050509B 0.225 X elliptical 0.03 N low SF rate
elliptical 050709 0.161 X, O galaxy 0.07
(150) Y SR galaxy in low SF region
050724 0.258 X, O, R elliptical 3.0 (120) Y low
SF rate elliptical 050813 1.8 ? X ?
galaxies, cluster 0.60 N - 050906 - -
- 0.13 N - 051103 2.6 Mpc ? - near
M81/M82 - - extragalactic SGR? 051105A - - -
0.03 N - 051210 0.114? X ? cluster 1.4 N -
051221A 0.547 X, O, R galaxy 1.4 N SF galaxy
051227 - X, O faint galaxy 0.9 (16) Y -
060121 gt1.5 X, O ? galaxies 2.0 N -
060313 - X, O ? cluster 0.7 N -
060502B 0.287? X elliptical _at_50kpc 0.09 N -
060801 1.131? X ? galaxies 0.5 N - 061006 - X,
O - 0.5 (130) Y - 061201 0.111? X, O ? galaxy
_at_34kpc 0.8 N - 061210 0.41? X ? galaxies 0.19
(85) Y - 061217 0.827? X ? galaxies 0.3 N -
070201 0.7 Mpc ? - near M31 - - extragalactic
SGR? 070209 - - - 0.1 N - 070406 - - - 0.7 N -
070429B 0.904 X, O galaxy 0.5 N UVOT
detection 070707 - X, O - 1.0 N -
070714B 0.92 X, O galaxy 2.9 (64) Y R25.5 host
070724 0.457 X galaxy 0.4 N SF galaxy
070729 - X - 0.9 N - 070809 - X, O - 1.3 N -
070810B - - - 0.08 N - 070923 - - - 0.05 N -
071112B - - - 0.3 N -
Guess at Redshift Histrogram Using Measurements
Hints
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High-z
Low-z
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6
5
4
SGRs
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2
1
0
0.0001
0.1
gt0.9
0.3
0.5
0.7
Redshift
HETE
IPN
INTEGRAL
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Short GRB Beaming
Burrows et al. 2006
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3 Types of GRBs
Swift GRBs (mostly)
long GRBs
short GRBs
log Eiso (ergs)
060218
SN GRBs
log T90 / (1z)
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3 Types of GRBs
070714B

060218
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Hot News
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Faint Short Hosts ? Large Distances
Lack of host galaxies to faint limits
suggests population of zgt1 short GRBs
short host magnitudes
Berger et al. 2007
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Long/short GRB 060614
- "long" GRB with no supernova - z 0.125
- Duration 103. seconds - Lightcurve has
similarities to short GRB with extended
emission
N.G. et al 2007
Gal-Yam et al., Fynbo et al., Della Valle et al.
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Two Classes of Short GRBs
Short bursts without EE - farther from galaxy -
weaker afterglows
Short bursts with EE - nearer to galaxy -
stronger afterglows
offset from center of host galaxy
Long GRBs Bloom et al. 2002
Troja et al 2007
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Future
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Implications for GW Detections
Assuming - 250 short GRBs/yr (BATSE) - 1/2
short GRBs are within z0.5 - g-rays collimated
to 10 beam - all short GRBs due to NS-NS
mergers ? NS-NS merger rate is gt300 Gpc-3
yr-1 Concsistent with NS-NS population
synthesis modeling O'Shaughnessy, Kalogera,
Belczynski (2005) For aLIGO NS-NS merger
sensitivity distance of 170 Mpc aLIGO
detection rate is gt6 yr-1
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Swift will be in orbit until gt 2020
(K. Thorne)
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High Energy Emission from Short GRBs
Compton Observatory
GLAST
T90 14 s (1 second hard pulse extended
emission) 100 MeV g's past main prompt phase
GLAST will be highly sensitive for HE
emission Launch May 2008
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Search for Faint GRBs
Lower Swift BAT thresholds 2 triggers
slews per day Observe with XRT UVOT for 2
ks Trigger is deemed a GRB if afterglow is
detected 1 month experiment planned in near
future
current thresholds
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Conclusions
Short GRBs - occur in external galaxies -
are less distant than long bursts ltzgt 0.4
short, ltzgt 2.3 long - do not occur
preferentially in star forming regions - are
less energetic than long bursts Eg 1048 short
Eg 1051 long Short GRB seem to - be
associated with old stellar populations - be
less beamed than long GRBs - have a wide and
possibly bi-modal redshift distribution Short
GRB may - be caused by NS-NS mergers - have
2 types associated with offset distance from host
galaxy - have a small fraction due to
extragalactic SGRs
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NS-NS Merger Lifetime
Nakar 2007
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