The Robotic Palomar 60-inch Optical Afterglow

Catalog: 2007

János Kelemen , Konkoly ObservatoryS. Bradley Cenko, CalTech. SRL

Derek Fox, Penn State Univ.

12008 Nanjing GRB Meeting Session 4

- telescope - observations & data reductions - photometric results - some preliminary results - conclusions

22008 Nanjing GRB Meeting Session 4

32008 Nanjing GRB Meeting Session 4

- telescopeSee reference:The Automated Palomar 60 Inch TelescopeS. Bradley Cenko,1 Derek B. Fox,2 Dae-Sik Moon,1,3 Fiona A. Harrison,1 S. R. Kulkarni,4 John R. Henning,5 C. Dani Guzman,6 Marco Bonati,5 Roger M. Smith,5 Robert P. Thicksten,5 Michael W. Doyle,5 Hal L. Petrie,5 Avishay Gal-Yam,4,7 Alicia M. Soderberg,4 Nathaniel L. Anagnostou,8 and Anastasia C. Laity8

Publications of the Astronomical Society of the Pacific, 118:1396–1406, October 2006

42008 Nanjing GRB Meeting Session 4

- telescope Filter characteristics

Filter calibrations: Jordi et al. (2006).

52008 Nanjing GRB Meeting Session 4

- observations & data reductions

62008 Nanjing GRB Meeting Session 4

- observations & data reductions

No automatic methods Data reduction by manual aperture photometry Photometric standards: USNO, SDSS Accuracy : 18 0.05 mg. 22 0. 2 mg. >22 0.3 – 0.5 mg.

72008 Nanjing GRB Meeting Session 4

- some preliminary results

Ref: Cenko et al, in

preparation

82008 Nanjing GRB Meeting Session 4

- some preliminary results

Ref: A. Zeh, and S. Klose, and D.A. Kann, ApJ Vol. 637, 2006,

pp. 889 - 900

92008 Nanjing GRB Meeting Session 4

- some preliminary results: the case of „dark” bursts

In our sample, nearly 50% of afterglows are “dark” bursts (OX < 0.5)

Ref: Cenko et al, in preparation

102008 Nanjing GRB Meeting Session 4

- some preliminary results: the case of „dark” GRB-s

DEFINITION based on optical versus X ray spectral index: βOX < 0.5

(Jakobsson et al. 2004).

Ref: Cenko et al, in preparation

Correction for host absorptionassuming β(optical) ~0.6 (average for bright SWIFT events)

112008 Nanjing GRB Meeting Session 4

- some preliminary results: the case of „dark” bursts

Ref: Cenko et al, in preparation

Early period:optical to X –ray spectral index highly variable

Later: became constant but below 0.5 => DARK burst

122008 Nanjing GRB Meeting Session 4

0.0 1.0 2.0 3.0 4.0 5.0

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

Z versus α (y = α*x +b) on the log-log plane

- some preliminary results

α Z

132008 Nanjing GRB Meeting Session 4

- some preliminary results Color diagrams based on all 2005-2006-2007 P60 g, r, i, z, observations

GRB OT

-4 -3 -2 -1 0 1 2 3 4 5-4

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5 (g-r) - (r-i) colors

g-ir-i

142008 Nanjing GRB Meeting Session 4

- some preliminary results Color diagrams based on all 2005-2006-2007 P60 g, r, i, z, observations

GRB OT Stars

-4 -3 -2 -1 0 1 2 3 4 5-4

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(g-r) - (r-i) colors

g-ir-i

152008 Nanjing GRB Meeting Session 4

- some preliminary results Color diagrams based on all 2005-2006-2007 P60 g, r, i, z, observations

GRB OT

-4 -3 -2 -1 0 1 2 3 4 5

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(r-i) - (i-z) colors

r-ii-z

162008 Nanjing GRB Meeting Session 4

- some preliminary results Color diagrams based on all 2005-2006-2007 P60 g, r, i, z, observations

GRB OT Stars

-4 -3 -2 -1 0 1 2 3 4 5

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(r-i) - (i-z) colors

r-ii-z

172008 Nanjing GRB Meeting Session 4

- What about the individual colors? Z values from http://www.mpe.mpg.de/~jcg/grbgen.html

Pseudo-redshift Calculator for G-Ray Bursts, A. Pélangeon & J-L. Atteia

0 1 2 3 4 515

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Z – g(1Day) plotZ

g m

ag.

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Z – ip(1Day) plotZ

ip m

ag.

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Z - R(1Day) plot

Z

R m

ag.

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Z - zp(1Day) plotZ

zp m

ag.

182008 Nanjing GRB Meeting Session 4

- some preliminary results What about the individual colors?

0 1 2 3 4 515

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Z – g(1Day) plotZ

g m

ag.

0 1 2 3 4 515

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Z – ip(1Day) plotZ

ip m

ag.

0 1 2 3 4 515

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Z - R(1Day) plot

Z

R m

ag.

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Z - zp(1Day) plotZ

zp m

ag.

0 < Z < 2.5

192008 Nanjing GRB Meeting Session 4

- some preliminary results (grb060206: 4.048; grb060210: 3.91; grb060906:3.686)

0 1 2 3 4 515

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Z - g (1Day) plotZ

g m

ag.

0 1 2 3 4 515

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Z - ip(1Day) plot

Z

ip m

ag.

0 1 2 3 4 515

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Z - R(1Day) plot

Z

R m

ag.

0 1 2 3 4 515

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Z - zp(1Day) plotZ

zp m

ag.

202008 Nanjing GRB Meeting Session 4

- some preliminary results why the big scatter? What about the individual

colors?

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Z - g (1Day) plotZ

g m

ag.

0 1 2 3 4 515

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Z - ip(1Day) plot

Z

ip m

ag.

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Z - R(1Day) plot

Z

R m

ag.

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Z - zp(1Day) plotZ

zp m

ag.offse

t at h

igh Z

212008 Nanjing GRB Meeting Session 4

- some preliminary results High redshift bump ??

0 1 2 3 4 515

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Z - g (1Day) plotZ

g m

ag.

0 1 2 3 4 515

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Z - ip(1Day) plot

Z

ip m

ag.

0 1 2 3 4 515

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Z - R(1Day) plot

Z

R m

ag.

0 1 2 3 4 515

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Z - zp(1Day) plot Z

zp m

ag.

222008 Nanjing GRB Meeting Session 4

- some preliminary results• High redshift bump

• synthetic colors based on polinomial regression

of the redshift – magnitude(1Day) diagrams

232008 Nanjing GRB Meeting Session 4

- some preliminary results• synthetic colors based on polinomial

regression (similar structure)

-4 -3 -2 -1 0 1 2 3 4 5

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1

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(g-r) - (r-i)

(g-r) - (r-i)starssynth poli.

(g-r)

(r-i

)

242008 Nanjing GRB Meeting Session 4

- some preliminary results• synthetic colors based on polinomial

regression (similar structure)

-4 -3 -2 -1 0 1 2 3 4 5

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-3

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-1

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1

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(r-i) - (i-z)

(r-i) - (i-z)starssynth poli.

(r-i)

(i-z

)

- conclusions

252008 Nanjing GRB Meeting Session 4

- conclusions the case of the „dark” bursts

262008 Nanjing GRB Meeting Session 4

- conclusions the case of the „dark” bursts P60 80 % detection efficiency P60 was able to detect optical afterglow emission from a large fraction

(∼ 80%) of events for which observations began within an hour of the burst trigger.

272008 Nanjing GRB Meeting Session 4

- conclusions the case of the „dark” bursts P60 80 % detection efficiency strange color-color diagrams

282008 Nanjing GRB Meeting Session 4

- conclusions the case of the „dark” bursts P60 80 % detection efficiency strange color-color diagrams further GRBs needed

292008 Nanjing GRB Meeting Session 4

- conclusions the case of the „dark” bursts P60 80 % detection efficiency strange color-color diagrams further GRBs needed

302008 Nanjing GRB Meeting Session 4

ADVERTISEMENT COMING SOON !!!

- conclusions the case of the „dark” bursts P60 80 % detection efficiency strange color-color diagrams further GRBs needed

... Now this is not the end. It is not even the beginning of the end.

But it is, perhaps, the end of the beginning... Sir Winston Churchill,

Speech in November 1942

312008 Nanjing GRB Meeting Session 4