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 : IntroGRBs : IntroGRBs : IntroGRBs : Intro

Map by Robert Mallozzi

GRB Sky Distribution in Galactic Coodinates:Seven Years of BATSE Observations

HST image: GRB 990123 and its host galaxy. The scale in this STIS picture is 40 pixels / 1”.

GRB peak luminosity was

21053 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 10-15meters Rough nuclear radius

5.3 10-11 meters Hydrogen atom radius

1.8 meters Humans

8847 meters Height of Mount Everest

6.3 106 meters Earth’s radius

7.0 108 meters 2 10-8 pc Sun’s radius

1.50 1011 meters 5 10-6 pc Earth-to-Sun mean distance (1 Astronomical Unit = 1 AU)

2 1015 meters 0.65 pc Oort Cloud size (Sun’s “Sphere of Influence”)

3.081016 meters = 1 parsec (pc) = 3.26 light-years = 206,265 AU

4 1016 meters 1.3 pc Sun to nearest star (Proxima Centauri)

3 1017 meters 10 pc Supernova biological extinction distance

1.5 1018 meters 50 pc Trigonometric parallax distance determination limit

5.2 1018 meters 170 pc Distance to supergiant Betelgeuse (supernova in 104 yrs)

1.52 1019 meters 500 pc Milky Way semi-thickness (~ 95% of stars contained)

3.9 1020 meters 13 Kilo pc Milky Way disk radius

2 1021 meters 65 Kilo pc Rough Milky Way dark matter halo radius

1.9 1022 meters 620 Kilo pc Distance to M31 (Andromeda Nebula)

7 1023 meters 22 Mega pc Distance to center of Virgo cluster of galaxies

3.0 1025 meters 1 Giga pc Luminosity distance to z=0.158 quasar 3C273

1.3 x 1027 meters 5 Giga pc Most distant known quasars; Gamma-Ray Bursters

Selected Power Scales ( Niel Brandt niel@ast.cam.ac.uk) 

150 watts Human being under normal conditions

2 104 watts Car

1 105 watts Running Tyrannosaurus Rex

3 108 watts Nuclear power reactor

3 108 watts Rough thunderstorm electrical power generation rate

3 1011 watts USA average electricity usage rate in 1986

8 1013 watts Powerful nanosecond pulse laser

4 1026 watts = 1 Lo = Solar luminosity

4 1030 watts 1 104 Lo Cygnus X-1 X-ray luminosity (few solar-mass black hole)

1 1031 watts 3 104 Lo Crab Nebula energy output

5 1035 watts 1 109 Lo Type II supernova peak photon luminosity

3 1036 watts 8 109 Lo Milky Way power output

1 1039 watts 4 1011 Lo 108 solar mass accreting black hole (~ quasar luminosity)

4 1032 watts 1 1013 Lo Rough luminosity of Galactic-halo gamma-ray burst

2 1041 watts 3 1012 Lo Luminosity of z=2.286 ultraluminous galaxy F10214+4724

1 1042 watts 3 1022 Lo 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

ErgophobiaErgophobia

2 1033 1021 10-1 = 2 1053 ergs Msun c2

GRB 990123 @ z = 1.61 E ~ 3 1054 ergs

and the Great Silence ?

GRB “Pulse Paradigm”

GRBs : LGRBs : Lpeakpeak vs. vs. GRBs : LGRBs : Lpeakpeak vs. vs.

GRBs : LGRBs : Lpeakpeak vs. vs. GRBs : LGRBs : Lpeakpeak vs. vs.

CCFLag

Time

A Main Sequence “HR Diagram for Gamma-Ray Bursts”

L53 ≈ 1.1 (lag/0.01 s)-1.15

970228

000131

Swift { Integral Differential }, post - Madau SFR vs. z

GRBs : RedshiftsGRBs : RedshiftsGRBs : RedshiftsGRBs : Redshifts

GRB 970228z = 0.695Day 200Rhost = 24.6

Scale: 1.37”/side

GRB 970508z = 0.835Day 200Rhost = 25.8Nucleus-OT offset < 0.01”Scale: 9.3” x 10.5”

GRB 971214z = 3.418Day 144Rhost = 25.5Nucleus-OT offset ~ 0.06”Scale: 6.35”/side

GRB 980329z > 2 (probable)Day 880Rhost = 28.Galaxy-radio offset ~ 0.75”Scale: 17.5”/side

GRB 980519z: unknownDay 750Rhost = 27.5Galaxy-OT offset ~ 1.5”Scale: 6.5”/side

GRB 980613z = 1.097Day 799Rhost = 26.Field ~ 6 galaxies; tidal interactionsScale: 18.4”/side

GRB 981226z = 1.097; no OT?Day 555Rhost = 24.3Nucleus-radio offset ~ 0.7”Scale: ~2.4”/side

GRB 990123z = 1.600Day 380Rhost (3 knots) = 28OT in outer, S. arm

Scale: 3.2”/side

GRB 990308z: unknownDay 468Rhosts = 27.Galaxy-OT offsets, 1.4” & 2.2” Scale: 6.5”/side

GRB 990506z: unknown; no OTDay 413Rhost = 25.0Radio centered on host (fhwm ~ 0.14")Scale: ~ 6.3”/side

GRB 990510z = 1.619Day 355Vhost = 28.Nucleus-OT offset 0.066” (~ 600 pc)Scale: 1.25”/side

GRB 990705z: unknown (low?)Day 387Vhost = 22.8Nucleus-OT offset 0.9”; face-on spiralScale: 7.6”/side

GRB 990712z = 0.430Day 287Rhost = 22.OT centered on bright red knotScale: 1.6”/side

GRB 991208z = 0.706Day 287Vhost = 24.6Nucleus-OT offset ~ 0.06”Scale: 2.5”/side

GRB 991216z = 0.77, 0.80, 1.02Day 123Rhost = 26.9host diameter, 0.3”BATSE: 3rd rankedScale: 3.2”/side

GRB 000131z = 4.50Day 6Rhost+OT = 24.6(VLT-Antu 8.2-m)

Scale: ~ 50”/side

GRB 000301cz = 2.03Day 34Rhost,OT = 26.9, 27.8Host unresolved

Scale: 0.9”/side

GRB 000418z = 1.118Day 47Rhost = 23.9Compact host (fhwm ~ 0.13")Scale: 5”/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.

WFC

SN1998bw

NFI SRC1

NFI SRC2

GRBs : RedshiftsGRBs : RedshiftsGRBs : RedshiftsGRBs : Redshifts

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.

Motivation. Our understanding of short bursts is limited to their -ray characteristics.

> 100 keV > 300 keV

0 500 ms

Akerlof et al.

GRBs : IntroGRBs : IntroGRBs : IntroGRBs : Intro

Measurement Uncertainties:

• “Experimental error”

• Power law extrapolation

• “Bumps and Wiggles”

Range of Optical Magnitudes

At ~ 10 s: 10 – 16 mags

GRBs : IntroGRBs : IntroGRBs : IntroGRBs : Intro