Luigi Piro IASF-INAF Rome

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Luigi PiroIASF-INAFRome
Lighthouses throughout the Universe Cosmology
with GRB
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The brightest AND most distant sources
E(iso) up to 1053-1054 erg in few seconds
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X-ray cosmology with GRB

• Tomography of the Universe
• Study the evolution of metals star formation
  with z
• The X-ray forest WHIM
• Dark energy and extension of SN results at zgt1
• Identify high-z GRB and their obscured host
  galaxies (X-rays and gamma-rays pierce through)
  at z7-20 when the first stars galaxies formed

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X-ray Tomography with GRB

• (Piro et al, ApJ 05)

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X-ray absorption in the GRB local environment

• X-ray absorption column densities in the
  afterglow NH1021-22 cm-2 (Stratta et al 2000,
  Campana et al 2006)
• Consistent with NH in Giant Molecular clouds

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Tomography of the Universe I

• Map the metal evolution vs z

Simulations of X-ray edges produced by metals
(Si, S, Ar, Fe) by a medium with column density
NH5 1022 cm-2 and solar-like abundances in the
host galaxy of a bright GRB at z5., as observed
ESTREMO-WFXRT with an observation starting 60 s
after the main pulse and lasting 60 ksec
Ar
S
Fe
Si
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Tomography of the Universe II WHIM and the X-ray
forest

• From models most of the baryons in the locat
  (zlt1-2) Universe in hot or warm filamentary
  structures heated by the gravitational pull of DM
  
• Observational evidence X-ray absorption line in
  the spectrum of bright nearby quasars (e.g.
  Nicastro et al 2005)

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Dark matter WHIM X-ray forest
Structure simulation from Cen Ostriker (1999)
?
Simulations of WHIM absorption features from OVII
as expected from filaments (at different z, with
EW0.2-0.5 eV from Hellsten et al 98) in the
l.o.s. toward a GRB with Fluence4 10-6 as
observed with ESTREMO-WFXRT (in 100 ksec). About
10 of GRB (10 events per year per 3sr). See
poster by Corsi et al
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GRB as standard candles new rulers to measure
the Universe

• Ghirlanda et al 2004, Amati et al 2002

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Dark GRB and the dark Universe

• About 20 of GRB are Dark (no optical afterglow)
• Very high extinction in dusty environment
• High z events (Ly alpha forest absorption at zgt5)

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GRB050908 z6.3

• Kawai et al 2005

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ESTREMO/WFXRT

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• Mission profile
• Wide field monitor in the X/hard-X range to
  localize transients
•          Fast (lt1 min) autonomous follow-up
  observations with X-ray telescope (2000 cm2) with
•      High resolution X-ray spectroscopy (0.1-10
  keV range, 2eV resolution below 2 keV with TES
  microcalorimeters)
•          wider field (30-60) for imaging with
  5-10 resolution (CCD) for extended faint
  structures and cluster survey
•          Low background 600 km equatorial orbit
  (as BeppoSAX)
• Trade-off study driven by scientific requirements
  is being carried out

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Scientific drivers of ESTREMO/WFXRT

• X-ray cosmology
• GRB as cosmological beacons
• Study of Cosmological structures in X-Rays WHIM
  and Clusters (high resolution spectroscopy and
  wide imaging in emission)
• Extreme physics of transient phenomena in the
  Universe (Black Holes, GRB engines and
  progenitors)