Summary LGRB progenitor (fairly) certain several cases with clear - - PowerPoint PPT Presentation

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Summary

• LGRB progenitor (fairly) certain – several cases with clear

Type Ib/c SNe association (hypernovae) but most of these are associated with under-luminous GRBs)

• May be a large population of only-just-relativistic events
• Swift finds only a few SGRBs per year; most with X-rays
• Can be hard to associate with a host (faint, kicks…)
• The nearest SGRBs may be the hardest to associate with

host (angular offset could be large?)

• Unclear how best to distinguish SGRBs from SGRs
• Energy budget unclear for both classes. Likely to be

beamed for LGRBs (need to get out of the star). Less clear cut for mergers but they probably have a broader jet

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GRB051103: an SGR Giant Flare?

• Predicted R band magnitude at

3 days would be ~34

• Progenitor is a young neutron

star, hence may expect to find: – Star formation – Supernova remnant – Massive star clusters

• Most nearby events come from

IPN (all-sky) – poorly localised

Pink – UV (GALEX) Blue – 21cm Radio (THINGS survey) Green – Optical (Digital Sky Survey) The green lines show the boundary of the error ellipse

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Summary

• GRBs now a mature subject
• Have redshifts for hundreds of GRBs (all extragalactic)
• Despite this, many things are uncertain

– Progenitors (at least some LGRBs are CCSNe but what else?) – Emission process (non-thermal, thermal…) – Total energy budget – Use of GRBs as probes (find hosts, SFR tracer, cosmology…)

• In multi-messenger era how to maintain momentum?

– Need a post-Swift mission with “reasonable” localisation error – Need wide-field search capability (snapshot vs. tiling) as some facilities such as A-LIGO will provide a large error box – What does the GW communitywant? May not be the same as the broader GRB community (high-z, low L, mergers…)

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SVOM Satellite (France, China, Leicester)

ECLAIRS MXT PIM

Payload Interface Module

X Band VHF

Alert System

GRM

Gamma Ray Monitor

Follow-on from Swift: better energy coverage, pointing strategy (anti-Sun) and lower trigger energy range (4-300keV) Find nearby X-ray bright, low L GRBs (SN connection) and high-z GRBs (cosmology) Planned Phase B start in 2012/13 Launch hoped for 2016-2017 New plan – mission may split into two spacecraft (the “train”)

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Lobster concept

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Lobster concept

These modules provide ~500 sq. deg each but design is very

• scalable. Mini-version will be proposed to ESA S-class call.