recent progress in gamma-ray bursts:
DESCRIPTION
Recent Progress in Gamma-ray Bursts:. S. R. Kulkarni California Institute of Technology. Image Credit: NASA E/PO, Sonoma State University, Aurore Simonnet. Long & Short. T. Piran, Hebrew U. P. A. Price, U. Hawaii J. Rich, ANU M. Rauch, Carnegie K. Roth, Gemini Obs M. Roth, Carnegie - PowerPoint PPT PresentationTRANSCRIPT
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Recent Progress in Gamma-ray Bursts:
S. R. Kulkarni
California Institute of Technology
Image Credit: NASA E/PO, Sonoma State University, Aurore Simonnet
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Long & Short
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The Gang and collaboratorsT. Piran, Hebrew U.P. A. Price, U. HawaiiJ. Rich, ANUM. Rauch, CarnegieK. Roth, Gemini ObsM. Roth, CarnegieD. J. Sand, CaltechB. P. Schmidt, ANUS. Shectman, CarnegieA. M. Soderberg, CaltechM. Takada, Tohuku U.T. Totani, Kyoto U.W. T. Vestrand, LANLD. Watson, U. CopenhagenR. White, LANLP. Wozniak, LANLJ. Wren, LANL
G. Kosugi, NAOJ W. Krzeminski, CarnegieS. R. Kulkarni, CaltechP. Kumar, U. TexasD. C. Leonard, CaltechB. L. Lee, U. TorontoA. MacFadyen, IASP. J. McCarthy, CarnegieD. -S. Moon, CaltechD. C. Murphy, CarnegieE. Nakar, CaltechH. S. Park, LLNLB. Penprase, Pomona C.S. E. Persson, CarnegieB. A. Peterson, ANUM. M. Phillips, Carnegie
K. Aoki, NAOJE. Berger, CarnegieP. B. Cameron, CaltechR. A. Chevalier, U. VirginiaS. B. Cenko, CaltechL. L. Cowie, U. HawaiiA. Dey, NOAOS. Evans, LANLD. B. Fox, Penn S./CaltechD. A. Frail, NRAOH. Furusawa, TITA. Gal-Yam, CaltechF. A. Harrison, CaltechK. C. Hurley, UC BerkeleyM. M. Kasliwal, CaltechN. Kawai, TIT
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CollaboratorsT. Piran, Hebrew U.P. A. Price, U. HawaiiJ. Rich, ANUM. Rauch, CarnegieK. Roth, Gemini ObsM. Roth, CarnegieD. J. Sand, CaltechB. P. Schmidt, ANUS. Shectman, CarnegieA. M. Soderberg, CaltechM. Takada, Tohuku U.T. Totani, Kyoto U.W. T. Vestrand, LANLD. Watson, U. CopenhagenR. White, LANLP. Wozniak, LANLJ. Wren, LANL
G. Kosugi, NAOJ W. Krzeminski, CarnegieS. R. Kulkarni, CaltechP. Kumar, U. TexasD. C. Leonard, CaltechB. L. Lee, U. TorontoA. MacFadyen, IASP. J. McCarthy, CarnegieD. -S. Moon, CaltechD. C. Murphy, CarnegieE. Nakar, CaltechH. S. Park, LLNLB. Penprase, Pomona C.S. E. Persson, CarnegieB. A. Peterson, ANUM. M. Phillips, Carnegie
K. Aoki, NAOJE. Berger, CarnegieP. B. Cameron, CaltechR. A. Chevalier, U. VirginiaS. B. Cenko, CaltechL. L. Cowie, U. HawaiiA. Dey, NOAOS. Evans, LANLD. B. Fox, Penn S./CaltechD. A. Frail, NRAOH. Furusawa, TITA. Gal-Yam, CaltechF. A. Harrison, CaltechK. C. Hurley, UC BerkeleyM. M. Kasliwal, CaltechN. Kawai, TIT
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Long Duration Bursts:
Collapsar Model: Woosley, Heger, MacFadyen
Kulkarni et al.Bloom et al.Frail et al.Berger et al.Soderberg etal
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SN 1998bw/GRB 980425
Galama et al. 1998, Kulkarni et al. 1998 E~1048 erg (isotropic)
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Collapsar: The Movie
A Hollywood-Bollywood Production
From Bogus Enterprise,A Division of General
Propaganda
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QuickTime™ and aYUV420 codec decompressor
are needed to see this picture.
With physics and lots of hardwork (MacFadyen)
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A New Family of Cosmic Explosions:
Soderberg
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Keck Laser Guide Star AO
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Progenitors of Ibc SNe: A Hot Result
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Palomar 60-inch: A second life
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Exploitation of GRBs has already begun
Reichart et al. 2005 Berger et al.
GRB 050904: z=6.2Observations at 3 hours (P60, optical; SOAR, NIR)
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Two classes of GRBs
Short - Hard
Long - Soft
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Summarizing Four Papers
1. Fox et al. “The afterglow of GRB 050709 and the nature of the short-hard γ-ray bursts”, Nature, October 6, 2005
2. Berger et al. “A merger origin for short γ-ray bursts inferred from the afterglow and host galaxy of GRB 050724”, Nature, November, 2005
3. Kulkarni “Modeling Macronovae”
4. Kulkarni et al. “Constraints on supernova-like emission associated with the short-hard gamma-ray burst 050509b
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Toward the SHB Progenitor: Redux• How far away are they?• How much energy do they release?
– is the energy release isotropic or collimated?– are the central engines long or short-lived?– Is there associated non-relativistic ejecta?
• What are the progenitors?– Clue (macro) = host galaxy + offset– Clue (micro) = circumburst environment
The key to answering these questions has been the precise positions enabled by the discovery of long-lived afterglows.
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GRB 050509B: Swift Detection
• BAT: very faint GRB• XRT: T+62 s detects 11
photons(!)• No optical, no radio.
very faint limits– Low energy event and/or
low density medium?
• Giant elliptical galaxy in cluster. z=0.22 Host?
Geh
rels
et a
l. 20
05
T90=40 ms
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Bloom et al. 2005
NSC J123610+285901 z=0.225
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HST Imaging: No Supernova
Kulkarni et al. 2005 Error radius = 9.3 arcsec 4 HST EpochsMay 14 to June 10
48 sources in XRT error circle
Giant elliptical Bloom et alL=1.5L*
SFR<0.1 M yr-1
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GRB 050709: HETE Detection
• A Hard spike, 84 keV• A Soft (PL) bump
(alpha=-2)• Roughly equal energy
in each component
Vil
lase
nor
et a
l. 20
05
T90=70 ms
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GRB 050709: Accurate Localization
Fox et al. 2005
SXCc
GRB QuickTime™ and aYUV420 codec decompressor
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HST imaging & search for supernova explosion
Fox et al. 2005
QuickTime™ and aYUV420 codec decompressor
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GRB 050709: Panchromatic Studies
• X-ray– source “flares” for initial 6 ks
of 18 ks in second epoch• Long-lived central engine?
– early and late flux do not fit
• Optical– inconsistent with simple PL
decay (slope=-1.3 --> -2.8)– “jet” break at T+10 d – SN limits MR>-12 mag
• Radio– violate simple AG model
Fox et al. 2005; Hjorth et al. 2005
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GRB 050724: Swift Detection
• Brightest Swift SHB• Hard spike/soft bump• X-ray, optical and radio
afterglow detected
Bar
thel
my
al. 2
005
T90=40 ms
15-150 keV
15-25 keV
T90=3 s250 ms
100 s
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30/47Barthelmy al. 2005
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Berger et al. 2005
GRB 050724: Swift
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32/47Kulkarni & Cameron
Red ellipticalz=0.258L=1.6 L*
SFR<0.03 M yr-1
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Toward the SHB Progenitor
• How far away are they?– At least some short bursts are z ~ 0.2
• How much energy do they release?– About 1049 to 1050 erg– Evidence for ``jets’’
• Is there an associated supernova explosion?– Supernova, if any, are faint (Mv > -13)
• What are they?– Both elliptical and star-forming host galaxies
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Comparison to Long Duratrion Gamma-ray Bursts
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Empirical Connection to Ia Supernovae
Nakar & Gal-Yam
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Binary Coalescence
1
Collapsar
Magnetar
1
1 1 1
Energy Density Host Offset No SNe
1
1 0 00
0
1
0 0
1
The Score Card
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Holy smokes, he is dead?!!
Ph: Glendinning
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Coalescence of Neutron Stars (Shibata)
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Black Hole-Neutron Star (Rupert, Janka)
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Macronova
• Is there a sub-relativistic explosion accompanying short hard bursts?
Li & Paczynski 1998
• If so, (observationally)> Nova< Supernova
=> “Mini-supernova” or “Macronova” Kulkarni
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Macronova Model
• Parameters: Mejecta & v=c
• Composition– Free Neutrons– Radioactive Nickel– Neutron Rich Material (non-radioactive)
• Injection of energy essential for macronova to shine and be detectable
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Nickel Decay
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r-process and s-process elements
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Comparison to Data (GRB 050509b)
=0.5
=0.05
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The Macronova as a Reprocessor
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Quasars: A Historical Analogy, II
• Scintillation: Interplanetary Scintillation showed that quasars were compact
• The Central Engine: After three decades we have a working model involving black holes
• The Pesky Jets: Questions remain– FRI and FRII– What is the difference between radio quiet and radio loud AGN?
• Unification: The desire to unify various classes of quasars drove much of quasar research.
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Quasars: A Historical Analogy, I
• Astonished & Impressed: The immense power and energy of quasars resulting from Schmidt’s discovery of redshift.
• Amused and Educated: Relativistic effects such as super-luminal motion were anticipated by Rees.
• Ruthless Exploitation: Ask not why quasars quase but simply use them as light beacons to study the IGM.
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The Macronova as a reprocessor
•Long lived central soure (e.g. magnetar)•Long lived accretion disk
There are already indications of tremendous late time activity.
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SHBs Observational Milestones
• 050509B– rapid arcsecond (+/-9.3”) localization of X-ray emission (AG?)– tentative host is elliptical galaxy in merging cluster (z=0.225) – macronova and SNe limits
• 050709 – sub-arcsecond position of X-ray afterglow– unambiguous identification of spiral host galaxy & redshift (z=0.16)– discovery of optical afterglow– evidence that outflows are jet-like– evidence that central engines remain active for days to weeks
• 050724 – discovery of first radio afterglow– unambiguous identification of red elliptical host galaxy (z=0.257)
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Coalescence --> Black Hole (Shibata)
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Gal Yam
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Possible SHB Progenitors
• Magnetar – Highly magnetized young neutron star (1014-1015 G)– Crustal breaking and magnetic reconnection = hyper-flares – short (0.2 s) hard pulse and long (300 s), soft pulse– Dominant timescale is Alfven velocity in NS
• Collapsar– Massive star core collapses to black hole + short-lived accretion disk– Nicely explains long-soft bursts– Dominant timescale is set by jet propagation in CO core (20 s)– Shorter timescales = collimated jet that wanders due to instabilities
• Binary Coalescence– Merging compact remnants (WD, NS, & BH) – Hypercritical accretion onto a newly formed BH– Dominant timescale is set by accretion disk viscosity
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58/47Taken from K.Thorne NSF Review talk
• Widely expected based on burst brightness distribution – <V/Vmax>=0.39+/0.02
– luminosity similar to long bursts but duration 100x less
– predicts faint AG
• Future z distribution will constrain merger timescale
• Tavnir et al (astro-ph) suggests 5-25% SHB are at d<100 kpc
• Good news for GW detectors like LIGO
Guetta & Piran (2005)SF + delay
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GRB/Host Offset Distributions• Offsets are notoriously
difficult to calculate. – Binary synthesis models– Galactic population of
binaries
• Depends on…– Merger times (0.1-100 Gyrs)– Proper motions (50-500 km/s)– Host galaxy potential– Binary evolution theory
• Future offsets can help constrain all of above
Fryer, Woosley & Hartmann 1999
Col
laps
ar
NS/
NS
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GRB 050709: Optical AfterglowPr
ice
et a
l. 20
05 a
nd H
jort
h et
al 2
005
T+1.42 d T+2.39 d ΔT
Decays as t-1.3
1.5m Danish Telescope, La Silla
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GRB 050724: Gemini Spectra
Prochaska et al. ; Berger et al. 2005
z=0.257
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Palomar 60-inch: Now a robotic telescope