1. 1 „Particle physics and cosmology: the interface” 3.5.2006, Warsaw „Particle physics and cosmology: the interface” 3.5.2006, Warsaw Search for optical flashes of astrophysical origin with „  of the Sky” experiment Grzegorz Wrochna Soltan Institute for Nuclear Studies, Warsaw grb.fuw.edu.pl Gamma Ray Bursts as standard candles Very short GRB and primordial black holes GRB optical emission Experiment „  of the Sky”

2. 2 GRB as a tool for cosmology u Cosmology became experimental science u Universe space-time properties measured using supernovae as standard candles up to z = 0.97 u Gamma Ray Bursts may become more powerful standard candles u The farest GRB observed has z = 6.2 !

3. 3 Gamma Ray Bursts - GRB  Short (0.01-100s)  –ray pulses u From pointlike sources in the sky  Brighter than the rest of the sky (in  -rays) u Energy 10 51 erg (=10 10 years of Sun emission) u Distance up to z=6.2 u Frequency 2-3 per day u Discovered in 1967 by military satellites VELA u So far >3000 observed including ~100 in visible light distance measured for ~70  Observed in radio waves, X-rays,  ~GeV,TeV

4. 4 Izotropic distribution in galactic coordinates

5. 5 GRB spectrum GRB 940212 afterglow GRB 980329 10 GeV

6. 6 Different shapes Time:0.01-100s

7. 7 „Short” and „long” bursts

8. 8 Mechanizm błysków gamma

9. 9 Anisotrophy of very short (<0.1s) GRB? Cline, Matthey, Otwinowski astro-ph/9905346 astro-ph/0510309 Primordial black holes?

10. 10 V. short GRB / CMB correlation?! Colour map – CMB (WMAP) / GeV  (EGRET) correlations Wibig, Wolfendale, astro-ph/040939

11. 11 Swift GRB 2004.12.19 Precursor seen also in GRB 2005.01.24 and some others quark star B.Paczyński and P.Haensel (astro-ph/0502297) interpret prekursor as a collaps to a neutron star and the main burst as creation of a quark star

12. 12 GRB’s today and tomorrow Today: u gamma emission well understood u central engine(s) still uncertain Tomorrow: u coincidence with TeV photons, neutrinos, etc u optical observations before and during GRB u using GRB as standard candles for cosmology

13. 13 GRB as standard candles Cepheides-like correlations might allow us to study the Universe much farther than Supernovae Isotropic luminosity [10 51 erg/s] Isotropic energy [erg] E peak [keV] Hardness [ch1-ch3] Reichart et al., 2001 Sakamoto et al., 2003

14. 14 GRB releases energy >10 51 erg = 10 44 J in 0.1-100s The same will be released by the Sun oven its all life (10 10 years) G R B 0 3 0 3 2 9, z = 0. 1 7 G R B 9 9 0 1 2 3, z = 1. 6 If in M31 (Andromeda)  brighter than the Moon If in M42 (Orion nebula)  brighter than the Sun! E gamma > 10 4 x E visible seen by uninstrumented eye?

15. 15 BATSE & ROTSE 4 telephoto lenses CANON d=10 cm robotic mount follows GCN alerts Images 1999.01.23 20 s after BATSE alert Optical flash 9 m ! could be seen by binocular! The brightest so far

16. 16 1 min. – 10 cm photolenses 1 h – 30 cm amateur telescope 1 day – 1 m professional telescope 1 week – 6 m giant telescope 1 month – Hubble telescope

17. 17 Catching prompt optical emission No one knows were the next GRB will happen Standard approach: u wait for GRB alert and move there quickly l robotic telescopes listening to GCN: l BOOTES, (SUPER)LOTIS, MASTER, RAPTOR, REM, ROTSE, TAROT,... New approach needed: u look everywhere, all the time wide field of view (  steradians ?) l self-triggering  experiment „  of the Sky”

18. 18 „  of the Sky” - grb.fuw.edu.pl Design: continuous ~all sky survey (32×3000 images / night) large data stream ( 1 Terabyte / night) real time analysis multilevel trigger under construction (ready by fall 2006) Prototype: 2×16 CCD cameras, each 2000 × 2000 pixels Canon lenses f=85mm, f/d=1.2 field of view = 2 steradians = Swift BAT works from July 2004 in Chile Collaboration: Soltan Institute for Nuclear Studies, Warsaw Center for Theoretical Physics PAS, Warsaw Warsaw University Warsaw University of Technology

19. 19 „  of the Sky” prototype 2 CCD cameras 2000×2000 pixels 2 CCD cameras 2000×2000 pixels common field of view 33°×33° common field of view 33°×33° 32 cameras under construction 32 cameras under construction robotic mount robotic mount < 1 min. to any point in the sky < 1 min. to any point in the skyhttp://grb.fuw.edu.pl Tests in Poland Las Campanas Observatory, Chile, from 7.2004

20. 20 „  of the Sky”: robotic detector Autonomic operation according to programme: follows HETE or INTEGRAL field of view follows HETE or INTEGRAL field of view detects itself optical flashes detects itself optical flashes all sky survey twice a night (2×20min) all sky survey twice a night (2×20min) follows targets of GCN alerts follows targets of GCN alerts High reliability: remote-reset, Wake-on-LAN, Boot-from-LAN remote-reset, Wake-on-LAN, Boot-from-LAN selfdiagnostics (e-mail and SMS to Poland) selfdiagnostics (e-mail and SMS to Poland) During one year of operation: ~10 nights lost due to apparatus problems + ~30 nights lost due to weather ~10 nights lost due to apparatus problems + ~30 nights lost due to weather > 300 „good” nights, 1 000 000 sky images, 10 10 photometric measurements > 300 „good” nights, 1 000 000 sky images, 10 10 photometric measurements

21. 21 Flash recognition in real time multilevel trigger concept (a’la particle physics exp.) all pixels stars cosmics planes satellites bad pixels One night coincidence

22. 22 „  of the Sky”: GRB observations 89 GRB’s discovered by satellites 7.2004-7.2005: 5 – clouds (4) or apparatus off (1) 5 – clouds (4) or apparatus off (1) 18 – Northen hemisphere 48 – daytime or below horizon 16 – outside field of view, 4 limits better than others GRB 040916B, >13 m for t > t 0 +17min (publ. GCN 2725) GRB 041217, >11.5 m for t > t 0 +30min (publ. GCN 2862) GRB 050123, >12 m for t 12 m for t < t 0 -108min (publ. GCN 2970) GRB 050326, >11 m for t 11 m for t < t 0 -33min (publ. GCN 3146) 2 – within FOV: GRB 040825A (published: GCN 2677) 2 – within FOV: GRB 040825A (published: GCN 2677) >10 m for t 12 m for t = t 0 >9.5 m for t > t 0 +7s GRB 050412 (GCN 3240) >11.5 m / >11 m / >11.5 m limits before and during GRB limits before and during GRB

23. 23 Search for cosmic flashes „  of the Sky” prototype at LCO, July 2004 – July 2005 u ~100 flashes seen by both cameras, in one frame only (could be satellites reflecting sunlight) u 6 flashes seen in >1 frame (not confirmed/excluded by others) u 1 flash identified as CN Leo flare star outburst u Several slower star-flares detected off-line CN Leo EQ Peg

24. 24 „  of the Sky” general goal: study objects varying on scales from seconds to months Examples of night-life of stars - brightness vs time (one night)

25. 25 GRB optical observations Very few points <20s after GRB t 0 dashed line – „  of the Sky” range dotted line – filter corrected limits measurements

26. 26 Prompt optical GRB observations  „  of the Sky” is optimized for t < t 0 + 60 s u Only 14 measurements by other experiments exist in this range  Extrapolation to 30s from later time suggest, that „  of the Sky” will see ~1/4 of visible GRB „  of the Sky” limit prototype limit filter corrected limit Observed by other experiments Extrapolated from later mesurements

27. 27  of the Sky grb.fuw.edu.pl