Gamma-Ray Bursts
(1) The Pre-BATSE Era (1967-1991)
(2) The BATSE Era & “The Great Debate” (1991-1997)
(3) GRB Intrinsic Characteristics, Extrinsic Distributions
(4) The Early Afterglow Era (1997-2001)
(5) Swift (2003.?)
(6) Short Gamma-Ray Bursts
(7) Rapid Reaction Telescopes
Scientific Articles
1997: 77
1998: 161
1999: 298
GRBs : Intro
GRB Sky Distribution in Galactic Coodinates:
Seven Years of BATSE Observations
Map by Robert Mallozzi
HST image: GRB 990123
and its host galaxy. The
scale in this STIS picture is
40 pixels / 1”.
GRB peak luminosity was
21053 ergs s-1 (~ 1020 suns,
or ~ 109 galaxies).
GRB brightness at Earth
reached 9th magnitude. The
host galaxy is 24.3 mag.
Astronomical magnitude system is logarithmic, and arcane:
1 magnitude  factor of 2.512 in brightness,
5 magnitudes  factor of 100 in brightness, exactly.
[ So, (2.512)5 = 100 ].
6th magnitude is approximate limit of naked eye sensitivity.
GRB optical counterparts reach ~ 9th to 20th magnitude.
Detected GRB host galaxies are ~ 23rd to 26th magnitude,
1004 (100 million)  fainter than naked eye sensitivity.
Selected Length Scales (  Niel Brandt niel@ast.cam.ac.uk)
1.44  10-15 meters
5.3  10-11 meters
1.8
meters
8847
meters
6
6.3  10
meters
8
7.0  10
meters
2  10-8 pc
1.50  1011 meters
5  10-6 pc
2  1015
meters
0.65 pc
3.081016 meters = 1 parsec (pc)
4  1016
meters
1.3 pc
17
3  10
meters
10
pc
18
1.5  10
meters
50
pc
5.2  1018 meters
170 pc
1.52  1019 meters
500 pc
3.9  1020 meters
13
Kilo pc
2  1021
meters
65
Kilo pc
1.9  1022 meters
620 Kilo pc
7  1023
meters
22
Mega pc
3.0  1025 meters
1
Giga pc
1.3 x 1027 meters
5
Giga pc
Rough nuclear radius
Hydrogen atom radius
Humans
Height of Mount Everest
Earth’s radius
Sun’s radius
Earth-to-Sun mean distance (1 Astronomical Unit = 1 AU)
 Oort Cloud size (Sun’s “Sphere of Influence”)
= 3.26 light-years = 206,265 AU
Sun to nearest star (Proxima Centauri)
Supernova biological extinction distance
Trigonometric parallax distance determination limit
Distance to supergiant Betelgeuse (supernova in 104 yrs)
 Milky Way semi-thickness (~ 95% of stars contained)
 Milky Way disk radius
 Rough Milky Way dark matter halo radius
 Distance to M31 (Andromeda Nebula)
Distance to center of Virgo cluster of galaxies
 Luminosity distance to z=0.158 quasar 3C273
 Most distant known quasars; Gamma-Ray Bursters
Selected Power Scales (  Niel Brandt niel@ast.cam.ac.uk)
150
2  104
1  105
3  108
3  108
3  1011
8  1013
4  1026
4  1030
1  1031
5  1035
3  1036
1  1039
4  1032
2  1041
1  1042
watts
watts
watts
watts
watts
watts
watts
watts =
watts
watts
watts
watts
watts
watts
watts
watts
1 Lo =
1  104 Lo
3  104 Lo
1  109 Lo
8  109 Lo
4  1011 Lo
1  1013 Lo
3  1012 Lo
3  1022 Lo
Human being under normal conditions
Car
Running Tyrannosaurus Rex
Nuclear power reactor
Rough thunderstorm electrical power generation rate
USA average electricity usage rate in 1986
Powerful nanosecond pulse laser
Solar luminosity
Cygnus X-1 X-ray luminosity (few solar-mass black hole)
Crab Nebula energy output
Type II supernova peak photon luminosity
Milky Way power output
108 solar mass accreting black hole (~ quasar luminosity)
Rough luminosity of Galactic-halo gamma-ray burst
Luminosity of z=2.286 ultraluminous galaxy F10214+4724
Rough luminosity of cosmological gamma-ray burst
Effects of a Local Gamma-Ray Burst
(… burst in the ‘hood)
The Good News  (Thorset, 1995) Gamma rays
alone will produce ionization in the stratosphere
and create massive amounts of NOx.
a catalytic ozone destroyer
The Bad News  (Shaviv and Dar Model:1kpc)
TeV cosmic rays will produce air showers of
energetic muons. At sea level, radiation
dosage will be about 30,000 rads.
100 times the radiation level lethal to humans
Ergophobia
2  1033 1021  10-1 = 2  1053 ergs
Msun
c2
e
GRB 990123 @ z = 1.61  E ~ 3  1054 (W/4p) ergs
and the Great Silence ?
GRBs : Lpeak vs. 
CCF
Lag
Time
GRBs : Lpeak vs. 
A Main Sequence “HR Diagram for Gamma-Ray Bursts”
L53 ≈ 1.1  (lag/0.01 s)-1.15
000131
970228
Swift
{ Integral
Differential },
post - Madau
SFR vs. z
GRBs : Redshifts
GRB 970228
z = 0.695
Day 200
Rhost = 24.6
Scale: 1.37”/side
GRB 980329
z > 2 (probable)
Day 880
Rhost = 28.
Galaxy-radio
offset ~ 0.75”
Scale: 17.5”/side
GRB 970508
z = 0.835
Day 200
Rhost = 25.8
Nucleus-OT offset
< 0.01”
Scale: 9.3” x 10.5”
GRB 980519
z: unknown
Day 750
Rhost = 27.5
Galaxy-OT offset
~ 1.5”
Scale: 6.5”/side
GRB 971214
z = 3.418
Day 144
Rhost = 25.5
Nucleus-OT offset
~ 0.06”
Scale: 6.35”/side
GRB 980613
z = 1.097
Day 799
Rhost = 26.
Field ~ 6 galaxies;
tidal interactions
Scale: 18.4”/side
GRB 981226
z = 1.097; no OT?
Day 555
Rhost = 24.3
Nucleus-radio
offset ~ 0.7”
Scale: ~2.4”/side
GRB 990506
z: unknown; no OT
Day 413
Rhost = 25.0
Radio centered on
host (fhwm ~ 0.14")
Scale: ~ 6.3”/side
GRB 990123
z = 1.600
Day 380
Rhost (3 knots) = 28
OT in outer, S. arm
Scale: 3.2”/side
GRB 990510
z = 1.619
Day 355
Vhost = 28.
Nucleus-OT offset
0.066” (~ 600 pc)
Scale: 1.25”/side
GRB 990308
z: unknown
Day 468
Rhosts = 27.
Galaxy-OT offsets,
1.4” & 2.2”
Scale: 6.5”/side
GRB 990705
z: unknown (low?)
Day 387
Vhost = 22.8
Nucleus-OT offset
0.9”; face-on spiral
Scale: 7.6”/side
GRB 990712
z = 0.430
Day 287
Rhost = 22.
OT centered on
bright red knot
Scale: 1.6”/side
GRB 000131
z = 4.50
Day 6
Rhost+OT = 24.6
(VLT-Antu 8.2-m)
GRB 991208
z = 0.706
Day 287
Vhost = 24.6
Nucleus-OT offset
~ 0.06”
Scale: 2.5”/side
GRB 000301c
z = 2.03
Day 34
Rhost,OT = 26.9, 27.8
Host unresolved
GRB 991216
z = 0.77, 0.80, 1.02
Day 123
Rhost = 26.9
host diameter, 0.3”
BATSE: 3rd ranked
Scale: 3.2”/side
GRB 000418
z = 1.118
Day 47
Rhost = 23.9
Compact host
(fhwm ~ 0.13")
Scale: 5”/side
Scale: ~ 50”/side
Scale: 0.9”/side
Summary: GRB Hosts, Source–Host Relationship
(1) GRB source magnitudes extrapolated to T0 (R ~ 9–16) are much
brighter than host galaxy magnitudes (R ~ 24–28):  104 – 106 !!!
(2) GRB sources are often offset from nucleus by ~ “galactic scale.”
(3) For significant fraction (~ 1/6), GRB source is “outside” but near the
(visible portion of) host galaxy.
(4) The galactic scale (FWHM) is often (~ 1/3) near HST resolution limit;
galaxies tend to be “small” (1–few kpc) at these earlier epochs.
(5) Appearance of interaction, and/or associated members of a group.
(6) Nonzero probability of incorrect association of GRB source with a
line-of-sight, relatively nearby (large angular scale) galaxy.
NFI SRC1
SN1998bw
NFI SRC2
WFC
GRBs : Redshifts
Motivation. Our understanding of short bursts is limited
to their -ray characteristics.
For long bursts, we have multi-
afterglows yielding redshifts, host
galaxies, evidence of progenitors
arising in star-forming regions,
(plus lots of theory  ).
For short bursts, we have the “Small
Bump” in the GRB duration plot. In
this work, we further quantify the
differences between long and short
GRBs, finding the two classes to have
distinct characteristics.
> 100 keV
0
500 ms
> 300 keV
Akerlof et al.
GRBs : Intro
Measurement Uncertainties:
• “Experimental error”
• Power law extrapolation
• “Bumps and Wiggles”
Range of Optical Magnitudes
At ~ 10 s: 10 – 16 mags
GRBs : Intro