Presentazione di PowerPoint

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Multiwavelength Italian Swift Team with
International Co-Investigators
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The Swift Mission

• Successfully launched on the 20th of November
  2004
• 267 days in orbit
• All instruments operating to spec
• BAT First Light 3 December 2004
• XRT First Light 11 December 2004
• First BAT Burst 17 December 2004
• First XRT Afterglow 23 December 2004
• UVOT First Light 12 January 2005
• First UVOT Afterglow 15 March 2005
• Calibration phase ended on Apr 5

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OUTLINE

• GRB theory and open matters
• Swift REM instruments, performances science
• GRB results
• Observationals procedures BA DS
• Secondary science X-Ray Binaries
• Conclusions Future

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GRB Characteristics (BATSESAX)

• Short (10 ms lt t lt 1000 s) and intense (E
  1054 erg) pulse of gamma rays occurring at
  random positions in the sky

• Isotropic distribution (BATSE)

• Afterglow era (SAX)

• Cosmological distances (SAX)

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The standard model fireball
UV/opt/IR/radio
gamma-ray
gamma-ray X-ray UV/optical IR mm radio
central photosphere internal
external shocks engine
(shocks)
(reverse) (forward)

Emission mechanism synchrotron emission from
power-law distribution electrons in highly
relativistic outflows
Rees Meszaros 1994 Paczynski Xu 1994
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Progenitors long GRBs
Light curves
Spectra
GRB 021211 (Massimo Della Valle, Daniele
Malesani, Stefano Benetti, Vincenzo Testa,
Mario Hamuy, L. Angelo Antonelli, Guido
Chincarini, Gabriele Cocozza, Stefano Covino,
Paolo D'Avanzo 7 coautori AA 406, L33-L37
(2003))
SN - Connection
GRB 980425 (Galama et al., 1998) First GRB SN
association
GRB 031203 (Daniele Malesani, Gianpiero
Tagliaferri Guido Chincarini, Stefano Covino,
Massimo Della Valle, Dino Fugazza, Paolo
Mazzali, Filippo M. Zerbi, Paolo D'Avanzo 17
coautori ApJ 609, L5-L8 (2004))
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The data gap

• Beppo-SAX takes at least 6-8 hours to perform an
  afterglow follow-up observation with its narrow
  field instruments. During this time, afterglow
  fades orders of magnitude.

Swift was designed to fill in the gap making
very early observations of the afterglows,
beginning approximately a minute after the burst.
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Swift Mission

• Burst Alert Telescope (BAT)
• 15-150 keV
• FOV 2 steradiants
• Centroid accuracy 1 - 4
• X-Ray Telescope (XRT)
• 0.2-10.0 keV
• FOV 23.6 x 23.6
• centroid accuracy5
• (UVOT) UV/Optical Telescope
• 30 cm telescope
• 6 filters (170 nm 600 nm)
• FOV 17 x 17
• 24th mag sensitivity (1000 sec)
• Centroid accuracy 0.5

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• A fast moving telescope
• Alt-az 60 cm f/8 RC silver-coated
• 2 Nasmyth foci (one idle)
• 60 deg 5 sec to any ?,? in 60 sec
• 10x10 am2 FoV

• with a high throughput NIR Camera
• 10x10 am2 FoV
• 1.2 as pixel scale (diff.limited)
• 0.9-2.3 microns (Z,J,H,Ks)
• 512x512 HgCdTe chip _at_77 Kelvin
• Wobbling plate for dithering

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Observing Scenario

1. Burst Alert Telescope triggers on GRB, calculates
   position on sky to lt 4 arcmin
2. Spacecraft autonomously slews to GRB position in
   20-70 s
3. X-ray Telescope determines position to lt 5
   arcseconds
4. UV/Optical Telescope images field, transmits
   finding chart to ground

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BAT Bursts

• 66 GRBs detected/imaged since Dec. 17 (33.5
  weeks as of 08/30/05)
• 041217 050315 050410 050502B 050603 050715 050730
  050815
• 041219A,B,C 050318 050412 050505 050607 050716 05
  0803 050819
• 041220 050319 050416A,B 050507 050701 050716 05080
  5 050820A,B
• 041223 050326 050418 050509A,B 050712 050721 0508
  07 050822
• 041224 050401 050421 050525 050713A,B 050724 0508
  13 050824
• 041226 050406 050422 050528 050714B 050726 050814
  050830
• 041228
• 050117
• 050124
• 050126
• 050128
• 050202
• 050215A
• 050215B
• 050219A,B
• 050223
• 050306

Average rate is 90/year
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(No Transcript)
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RESULTS
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Progenitors short GRBs (I)
GRB 050509B first detection of the X-ray
afterglow of a short GRB (N. Gehrels et al., 2005
Nature)
GRB 050709 first detection of the optical
afterglow of a short GRB (S. Covino, D. Malesani,
G.L. Israel, P. DAvanzo 29 coauthors, 2005
AAL, submitted)
GRB 050724 again a detection of the optical
afterglow of a short GRB (S.D. Barthelmy, G.
Chincarini, D.N Burrows, N. Geherels, S. Covino,
A. Moretti, P. Romano, P.T. OBrien, C.L.
Sarazin, C. Kouvelotou, M. Goad, S. Vaughan, G.
Tagliaferri, B. Zhang, A. Antonelli, S. Campana,
P. DAvanzo 12 coauthors, 2005 Nature,
submitted)
Host Galaxies
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Progenitors short GRBs (II)
GRB 050509B GRB 050724 Host Galaxies
XRT position
Host Galaxies of long GRB

• early type elliptical
• red color spectrum
• no emission lines

vs.
Low star formation rate Population of very old
stars
GRB 050709 Host Galaxy

• late type irregular
• blue color spectrum
• Ha emission line

off-core (3 kpc) position of the OT, consistent
with a system of age 109 y
BUT...
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The fartest GRB ever observed
z 6.3! ESO press release 12 Sep 2005
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Observational procedures (I)
REM
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Observational procedures (II)

• Burst Advocate
• Rem Duty Scientist

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Science with Swift REM
GRB!
GRBs observed rate now is about 2 burst per week
but also latitude/longitude constraints have to
be taken into account. This is leaving free Swift
REM observing time that is largely used for
Any program requesting fast multi-frequency
observations

1. Multifrequency monitoring of AGNs
2. X-Ray Binaries
3. Flare Stars
4. Others...

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X-Ray Binaries
SXRT

• sporadic outbursts
• long quiescent periods

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Doppler tomography

• image reconstruction
• monitoring at different orbital phases
• bidimensional maps

spectral lines
and corresponding velocity coordinates
familiar spatial coordinates
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Centaurus X-4 quiescent optical emmission
Ha HeI
5875 HeI 6678

• circular ring-like structure in
• emission
• emission from the companion
• visible hot spot

Irradiation hypothesis

• DISC
• Ha emission from external
• region
• HeI emission from internal
• region

• COMPANION STAR
• Ha emission from low
• velocity regions
• HeI emission from high
• velocity regions

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Origin of the quiescent emission (I)
The companion fills its Roche Lobe and could be
subject to irradiation from the NS
fase 0 fase 0.25
fase 0.5 fase 0.75
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Origin of the quiescent emission (II)
EW 4.4 0.5 Å
log FHa log EW(Ha) 0.113(B-V)2 1.188(B-V)
7.487 (Soderblom et al., 1993)
FHa 7 x 106 erg cm-2 s-1
LX 4 x 1032 erg s-1 (Campana et al., 2004)
FX LX/(4pa2) 5 x 108 erg cm-2 s-1 a 3.6
solar radius
1 of the incident X-Ray flux should be
reprocessed to Ha photons
LHa f1f2LX 5 x 10-3 LX 0.5 LX f1 solid
angle f2 0. 3 (Osterbrock 1987)
D'Avanzo et al. 2005, AA, accepted
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ms X-Ray Pulsars
Campana, D'Avanzo et al., 2004, ApJ
Source name X period (Hz/ms) Orbital period (h) Optical counterpart in quiescence
SAX J1808.4-3658 401 Hz /2.49 ms 2.01 hrs I21
XTE J1751-305 435 Hz /2.30 ms 0.70 hrs Rgt23.1, Igt21.6
XTE J0929-314 185 Hz /5.41 ms 0.73 hrs n
XTE J1807-294 191 Hz /5.24 ms 0.67 hrs n
XTE J1814-338 314 Hz /3.18 ms 4.30 hrs R gt 23
IGR J00291-5934 599 Hz /1.67 ms 2.46 hrs I gt 21
HETE J1900.1-2455 377 Hz/2.65 ms 1.39 hrs n
TNG approved proposal (P.I. P. DAvanzo)
ESO VLT proposal (in prep.)
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Conclusions (I)

• Exciting Swift results on
• GRB progenitors
• Host Galaxy morfology
• High z GRB
• New light on quiescent optical emission of SXRTs
• Opportunity to investigate the link between ms
  X-Ray Pulsars and ms Radio Pulsars

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Conclusions (II)

• Our results on GRB led to
• 42 GCN circulars
• 3 published papers
• 3 submitted papers
• 2 papers in preparation
• Our results on SXRT led to
• 1 paper published
• 1 approved TNG proposal
• 3 ESO proposals in preparation