of the SkyStudy of astrophysical phenomena with time scale from seconds to months

Search for optical counterparts of Gamma Ray Bursts (GRB)

„ of the Sky” APPARATUS

Prototype (working at LCO since 07.2004):

• 2 CCD cameras, 2000x2000 piksels each• lenses: Zeiss, f=50mm, f/d=1.4, FoV: 33o×33o

• limiting mag.: 10-11m (1 frame 10s), 12-13m (20 frames)

Apparatus under construction:

• 2×16 CCD cameras, 2000x2000 piksels• lenses: Canon EF f=85mm, f/d=1.2• FoV: 16 × 20o×20o = 2 steradians = Swift BAT FoV• limiting mag.: 12m (1 frame 10s), 14m (20 frames)

Robotic system:

The system works autonomously, according to scheuldewhich could be chaged via internet:

• follows Swift, HETE or Integral FoV• independently detects optical flashes in real time• twice a night makes full sky survey (2×20min)• follows satellite alerts distributed by GCN

Data analysis:

• 20000 stars / frame• 3000 frames = 25 GB / night / frame• on-line optical flash recognition

- algorithms inspired by particle physics- rejection of cosmic rays, planes, satellites

• data base of light curves of stars - off-line

http://grb.fuw.edu.pl

• Soltan Institute for Nuclear Studies: J.Mrowca-Ciułacz, K.Nawrocki, P.Sitek, M.Sokołowski, G.Wrochna• Center for Theoretical Physics, Polish Academy of Sciences: A.Majcher, L.Mankiewicz• Institute of Experimantal Physics, Warsaw University: M.Ćwiok, H.Czyrkowski, R.Dąbrowski, W.Dominik, L.W.Piotrowski, A.F.Żarnecki• Institute of Electronics Systems, Warsaw Univ. of Technology: K.Poźniak, R.Romaniuk, G.Kasprowicz, S.Stankiewicz• Faculty of Physics, Warsaw Univ. of Technology: M.Molak, J.Użycki• Faculty of Science, Card. Wyszyński University: K.Małek• In collaboration the ASAS project – Astronomical Observatory of Warsaw University: G.Pojmański, B.Pilecki, D.Szczygieł• Special thanks to prof. B.Paczyński (Princeton University) and all staff of the Las Campanas Observatory

FIRST RESULTS

Search for optical flashes:

• ~100 flashes <10s detectedflashing satellites

• 8 flashes >10s detectedincluding flare of CN Leo

Gamma Ray Bursts (GRB)• energy: 1051 erg = 109 years of Sun life• duration: 0.01-100s• distance: up to 14·109 light years (z=6.3)• frequecy: 2-3/day (2-3/week currently observed by satellites)• origin:

• hipernova – massive star collaps to a black hole?• merging two neutron stars into a black hole?

Poster background: Milky Way picture

in false colors taken by „ of the Sky” camera

Las Campanas Observatory (Chile)

Apparatus tested in Poland

Outburst of CN Leo flare star

automaticaly detected by „ of the Sky”The star has brighten 100× in seconds,

then faded in minutes

to = 2005.04.02 1:13:42 UT= 3462.55620 HJD

Serch for GRB optical counterparts:

• 96 GCN alerts received (>7.2004): 1 – apparatus off 4 – clouds27 – below horizon45 – daytime17 – outside FoV 2 – inside FoV

• limits 9m-12m published for GRB: 040825A, 040916, 041217, 050123,

050326, 050412, 050607, 060607