R. Margutti
Harvard University
LOS ALAMOS 2011
Where do we stand
Log(Flux)
Gamma-ray
Prompt
X-ray Flares
t-1
Is there any physical
link between a
prompt pulse
and an X-ray
flare?
Swift
Steep
Decay
10-100 s
Shallow
Decay
102-103 s
Normal
Decay
~104s
Log(Time)
Log(Flux)
Gamma-ray
Prompt
X-ray Flares
Temporal Properties
1.Pulse Asymmetry
2.Fast rise- Exponential
decay
Spectral Properties
1.Band spectral energy distribution
2.Peak energy evolution with time Ep(t)
3. Ep(t)-Liso(t)
4. Lag-Luminosity relation
Margutti et al., 2010,MNRAS, 406, 2149
Log(Time)
Flares are softer and less energetic time-stretched versions of a
prompt pulse
Lag-Luminosity
L(0.310keV )  t
0.950.23
lag
PROMPT Lag

LONG!!!!
FLARES
Margutti et al., 2010,MNRAS, 406, 2149
051221A
060801
050724
100117A
070724A
071227
050724
LOS ALAMOS 2011
LOS ALAMOS 2011
Different tools
Different definitions
(e.g. pulse-peak lag
vs. CCF lag)
PULSE property vs.
Time-averaged
measurements
Strongly dependent on
the definition of the
energy bands used
Using rest-frame
defined energy bands is
enough?
LOS ALAMOS 2011
Different tools
Different definitions
(e.g. pulse-peak lag
vs. CCF lag)
PULSE property vs.
Time-averaged
measurements
Strongly dependent on
the definition of the
energy bands used
Using rest-frame
defined energy bands is
enough?
LOS ALAMOS 2011
Homogenous analysis of a statistically significant
number of GRBs
Step back to the analysis of more basic effects that are
known to contribute to the lag measure to
understand how each of them is correlated to the
final lag measure
Time resolved approach to determine a MAP of the
obs. properties of GRBs with time.
LOS ALAMOS 2011
LOS ALAMOS 2011
Epeak (t)
alpha (t)
beta (t)
Lag (t)
Variability (t)
Pulses properties(t)
Pulses properties (E)
??
??
??
LOS ALAMOS 2011
1) Selection of a GRB
2) Production of a MAP of
properties
Galaxy NNN
050822
Gamma-Ray Burst
(GRB050822)
3) Writing of a document
ACT as a TEAM
Useful for
FUNDING
(we have something
to show..)
LOS ALAMOS 2011
WISH LIST:
GRB detected by Swift- Fermi
Prompt emission seen by XRT
Prompt emission see by UVOT
Bright
Known z
…good for GBM-BAT cross calibration…
LOS ALAMOS 2011
Raffaella: Variability Time scale of BAT; XRT expertise
(XRT+BAT spectral fits; pulse properties in the X-ray
regime)
Mike: Time-resolved lag using the CCF
John: Prompt Pulse properties
List of people to complete….
LOS ALAMOS 2011