short bursts -- an observational perspectivegrb07/presentations/klose.pdf · sylvio klose,...
TRANSCRIPT
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1Sylvio Klose, Thüringer Landessternwarte Tautenburg, Germany
Short bursts -- an observational perspective
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4 mag
+/- 2 mag
Kann & Klose (2007)
short afterglows: the typical light curve
long vs. shortafterglows:typically dm >~ 4 mag
• be fast• go deep
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3
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• dust and gas
• the outflow geometry
• extra light
Outline of the talk
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Challenge 1
the GRB environment(dust & gas)
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(A) long bursts
Kann, Klose, & Zeh (2006)
• inspired by GRB 970828 (Groot et al. 1998)• starting with Ramaprakash et al. (1998)
I. Photometry: GRB host extinctions*** ***
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(A) long bursts
Kann, Klose, & Zeh (2006)GRB 970828: Djorgovski et al. (2001)
pre-Swift era
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Fox et al. (2005)
GRB 050709
GRB 050709GRB 060121
(B) short bursts
de Ugarte Postigo et al. (2006);Berger et al. (2006)
4.6?
Multi-color data from short burst afterglows
mostly very bad sampled
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(B) short bursts
• GRB 050709: A_V = (0.67 +/- 0.19) mag (Ferrero et al. 2007a)• GRB 060121: A_V = (0.5 +/- 0.2 ) mag (de Ugarte Postigo et al. 2006)
GRB host extinctions
current situation: not satisfactory
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ANDICAM
GROND
in perspective: multi-color imaging
2 channels
7 channels
Gamma-Ray Burst Optical Near-Infrared Detector
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5 m
in
30 m
in
1 m
in
(A) long bursts II. Spectroscopy: early spectra*** ***
060607A, VLT, 8 min
060418, VLT, 10 min
061121, Keck, 14 min
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(B) short bursts Early spectra from short burst afterglows?
(no spectra at all)
current situation: not satisfactory
1 m
in
5 m
in
30 m
in
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Calar Alto 3.5-m, PMAS/PPak
(B) short bursts Observing with Integral Field Units
in perspective:
GRB 060605
Ferrero, Savaglio et al. (2007b)
star
star
star
ag
74“ x 64“
3D cube
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Challenge 2
afterglow geometry, jets
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(A) long bursts I. Photometry
• starting with GRB 990123 (Castro-Tirado et al. 1999)• and later GRB 990510
• first summarized by Frail et al. (2001)• Panaitescu & Kumar (2001)• Bloom et al. (2003)• and others
*** ***
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(A) long bursts Light curve breaks in long burst afterglows
Castro-Tirado et al. (1999) Stanek et al. (1999)
GRB 990123
R band
B,V,R,I bands
GRB 990510
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Zeh, Klose, & Kann (2006)
(A) long bursts Light curve breaks in long burst afterglows
pre-Swift era
Klose et al. (2004)
GRB 030226
UBVRIJHK bands
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long bursts
short bursts
Watson et al. (2006)
α = 1
see also Livio & Waxman (2000); Rosswog & Ramirez-Ruiz (2003); Janka et al. (2006)
(B) short bursts
0512
21A
, 061
006,
061
210
????4 mag
Light curve breaks in short burst afterglows
Berger (2007)
in perspective:
current situation: not satisfactory
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GRB 990123: Hjorth et al. (1999)GRB 990510: Covino et al. (1999); Wijers et al. 1999GRB 990712: Rol et al. (2000)
GRB 020813: Gorosabel et al. (2004); Lazzati et al. (2004)GRB 021004: Rol et al. (2004)
GRB 030226: Klose et al. (2004)GRB 030329: Greiner et al. (2003)
GRB 060218: Gorosabel et al. (2006)
list is incomplete
Polarisation data for long burst afterglows
(A) long bursts II. Polarimetry*** ***
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Lazzati et al. (2004)Gorosabel et al. (2004)
GRB 020813
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Greiner et al. (2003)R = 15.0t = 2040 secdP= 0.09 %
R = 20.6t = 9600 secdP= 0.48 %
VLT 8.2-m
GRB 030329
(A) long bursts The best sampled polarimetric light curve
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(B) short bursts
R (t=0.01 days) = 19.5R (t=1 day) = 24.5R (t=10 days) = 27.0
Polarimetric data from short burst afterglows?
in perspective:
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Challenge 3
extra light, SNe
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I. Mini-supernovae (Li & Paczynski 1998)
z = 0.1β = 1/3
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f = E_rad / Mc**2M = ejected mass
(B) short bursts *** ***
(1)(2)
(3)(4)
(5)(6)
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Short bursts, afterglows and upper limits
D.A. Kann
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GRB 050509B (no detected afterglow)
Observational constraints on the LP model
day 20
see also Hjorth et al. (2005)
(B) short bursts
in perspective:
day 1
current situation: strong constraints
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II. SN 1998bw light
Zeh, Klose, & Hartmann (2004)
(A) long bursts
• starting with GRB 980326 (Bloom et al. 1998)• inspired by GRB 980425/ SN 1998bw (Galama et al., Kulkarni et al. 1998)
*** ***
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28Ferrero et al. (2006), incl. data fromRichardson, Branch, & Baron (2006)
The GRB-SNe luminosity distribution(A) long bursts
extinction corrected
SN 1991D SN 1992ar
SN 1987K
GRB 991208
SN 1998bw
GRB 060218(SN 2006aj)
GRB 000911H_0 =71Ω _m = 0.27Ω_Λ = 0.73
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Kann & Klose (2007)
k = 0.0060
k = 0.0015
k = 0.60
k = 0.29
(B) short bursts Constraints on SN 1998bw light
k < 0.001 ?
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SN 1998bw peak magnitude (z)
k=0.001
k=1.0
VLT/FORS1, R-band, exposure times (seconds), S/N = 10
(B) short bursts What are the chances to detect SN light?
in perspective:
current situation: deep limits
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Summary
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10 yearsGRB afterglows 1997 - 2007
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„How can I get so much observing time?“
Challenge 4
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Short burst afterglows, an optical perspective
• obtaining multicolor imaging data (UBVRIJHK) is surely possible
• getting (early-time) spectra is possible
• setting constraints on extra light down to deep flux limits is possible; but the perspectives for detecting something are an open question
• detecting / constraining a light curve break in the optical bands might be hard
• obtaining a polarimetric light curve might be impossible at all
z, gas
dust
jets
mor
e an
d m
ore
diffi
cult
SNe
Anyway, we will try.