Title: A Subclass of GRBs as
1- A Subclass of GRBs as
- Possible LIGO-2 Gravitational-Wave Sources
- Jay P. Norris
- NASA/GSFC
- 1 The prevalent belief structure
- Some All? GRBs associated with SNe.
- 2 Demographics attributes of possible subclass
of nearby ultra-low luminosity GRBs and their
associates nearby type Ib/c SNe. - 3 Predicted range of GW strains detection rate
for GRB subclass
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3- GRB-SN Belief Sparse Knowledge Structure
- One very close ? 35 Mpc ultra-low luminosity
GRB and one not so close ? 680 Mpc subluminous
GRB - Both manifest the presence of Type 1c SNe.
- Constrained but open issue The delay in some
cases - ?TSNTGRB?simultaneous?
- Detection of GW signal could depend on accurate
knowledge of TSN or TGRB. Accurate TGRB is easy. - GW signal requires non-axisymmetric deformation
? Theoretical core collapses ? 10-4-10-2
to unity. - Is degree of non-axisymmetry related to GRB jet
opening angle via BH rotation?
4Figure 2. The detailed classification of SNe
requires not only the identification of specific
features in the early spectra but also the
analysis of the line profiles luminosity and
spectral evolutions. Cappellero Turrato
astro-ph/0012455
5E. Pian astro-ph/9910236 Revised BeppoSAX error
box for GRB 980425
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722 days
Iwamoto et al. 1998 Modeling yields core
collapse for SN1998bw within 0.7/-2 days of GRB
980425
12 days
40 days
8Young Baron Branch 1995
9GRB 011211 z 2.14 Reeves et al.
Nature 2001 416
Blue-shifted X-ray lines ? ? 0.09 assume ?jet
? 20º ne 1015 cm-3 ? GRB ejecta runs into SN
shell at R 1015 cm ? TGRB - TSN 4 days
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13- Are there T0_SN ? T0_GRB delays?
- SN 1998bw light curve has evidence for upturn
end of UV breakout ? which would place T0_SN
few days before T0_GRB. Modeling ?T -20.7
days - X-ray afterglow spectral analysis GRB 011211
suggests 4-day hiatus SN to GRB. - Type 1c SNe light curves not well studied and
are known to vary in width by at least a factor
of 3 - Cannot gauge T0_SN accurately by comparison with
SN 1998bw especially given GRB afterglow
photometry at faint magnitudes. -
- Theory ?T 10s - hrs Woosley et al.
collapsars - ?T ??? van Putten BH-torus
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15- Core-collapse SN Explode Asymmetrically
- Images of 1987A see ST Jan 2002 Wang
Wheeler - Elemental asymmetries in Wang et al.
2002 - SN remnants 1987A Cas A
- Polarization in SNe Wang et al.
2001 - Type 1a
- Type II 1-2 increasing with time
- Type 1b/c 3-7
- GRB observed by RHESSI Coburn Boggs
Nature - Some GRBs beamed into 4?/500/2 Frail et al.
2002 - SN Modeling strong polar ejections
- Pulsar space velocities
- ? Some SNe are rapidly rotating at core-collapse
high T/W. - Non-axisymmetric bar instabilities
possible ?
16- A Sub-Population of Nearby GRBs ?
- BATSE subsample 7 of soft-spectrum GRBs.
Defining characteristic Very long pulses with
long spectral lags 0.3 s. - Proportion increases to 50 near BATSE
threshold. - Additional Evidence for Nearby Spatial
Distribution - GRB980425/SN1998bw is canonical example at 38
Mpc. - Log NLog Fp has -3/2 slope cosmology
unimportant. - Tendency towards Supergalactic Plane similar to
SN Ib/c long-lag GRB and nearby galaxy sky
distributions similar. - Implications Detected sample d Ultra-low luminosity RGRB ¼ RSN Ib/c
- Could be LIGO II sources 4 yr-1 within
50 Mpc - see ApJ
2002 579 386
17Typical long-lag GRB detected by BATSE.
300 keV blue 100-300 keV green 50-
100 keV yellow 25- 50 keV red
18HETE-2 time profile for GRB 030329 5-120 keV
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20A Main Sequence HR Diagram for Gamma-Ray
Bursts L53 1.1 ? ?lag/0.01 s-1.15
Woosley MacFadyen 1999 Ioka Nakamura
2001 others predicted subclass of numerous
nearby GRBs low luminosity soft-spectrum
long-lag. Properties attributed to 1 large jet
opening angle 2 low ? 2-5.
21M. J. Hudson 1993
7200 km/s 100 Mpc z 0.024
22980425
971208
Virgo
23SNe Ib/Ic 62 detected 1954-2001.75
2/3 since 1998.0 With 85 at distances 100 Mpc. Only 10 of nearby SNe are detected.
24RGRB
25Fryer Holz Hughes 2002 Blondin Mezzacappa
DeMarino 2003 Bar instabilities
likely ? unity. Assuming 100 cycles
f 200-800 Hz source 1.3 ? 10-23 Expect 4 long-lag GRBs yr-1 50 Mpc and we know when they occur.
26- Summary
- Very good evidence that high-mass highly
energetic core-collapse SNe are associated with
GRBs one nearby a few cosmologically distant
examples of such associations. - Evidence indicates that these SNe and GRB events
are asymmetric ? high T/W. Are SN and GRB
simultaneous? - Long-lag soft-spectrum apparently nearby ultra
low-luminosity GRBs are numerous 50 near
BATSE threshold. - RGRB RSNIb/c.
- A few yr-1 detectable by LIGO
II. - Swift should see a larger fraction of long-lag
GRBs than BATSE. - ? Many chances to find the associated SNe and GW
signals
27The End
28G.M. Harry et al.
29Lmin
?vmax
L const. across jet
?vmin
Lmax
?jet
?jet varies ?view varies
?view varies 2?20?. outside jet
cone. inside profiled jet.
Beaming Fraction Viewing angle
Profiled jet ?4? Ld? constant Special
Relativity L? reflects ?? ? ?? ? L-1.
Lorentz contraction 30 Doppler boost
jet fastest on axis All three models realize
broad observed but narrow actual Luminosity and
Energy distributions.
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32GRBs Lpeak vs. ?
33CCF Lag
Time
GRBs Lpeak vs. ?
34- Possible Confirmation Approaches
- 1 Untriggered BATSE bursts For Fp cm-2 s-1 long-lag bursts predominate. But
larger localization errors IDing as bona fide
GRBs is problematic. - 2 400-500 additional triggered BATSE bursts.
- 3 Cross-correlation of nearby matter
distribution - d
- 4 Extrapolation of SNe light curves to T0
comparison with GRB times and positions J.
Bonnell. - 5 Swift