for the 1 st Advanced LIGO Science Run Jordan Camp NASA Goddard Space Flight Center Moriond Gravitation Meeting March 25 2015 Search Team Lindy Blackburn CfA Nelson Christensen Carleton College ID: 223733
Download Presentation The PPT/PDF document "LIGO - Fermi Sub-Threshold Search" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
LIGO - Fermi Sub-Threshold Search
for the 1
st
Advanced LIGO Science Run
Jordan Camp
NASA Goddard Space Flight Center
Moriond
Gravitation Meeting
March 25, 2015
Search Team
Lindy Blackburn (
CfA
)
Nelson Christensen (Carleton College)
Valerie
Connaughton
, Michael Briggs,
Binbin
Zhang (UAH)
Peter
Shawhan
(U
Md
)
Leo Singer (Goddard NPP)
John
Veitch
(U Birmingham)Slide2
Advanced LIGO is now operating
Washington
Louisiana
Gravitational Wave causes differential arm displacement
photodetector
signalSlide3
Advanced LIGO Sensitivity Goal
Factor 10 lower noise at high frequency
Higher power laser
Factor 10 lower noise at low frequency
Active seismic isolation
Factor 6 lower cutoff frequency
Multiple suspensions in series
Advanced LIGO
Initial LIGO BNS range
20
Mpc
Advanced LIGO BNS
range 200
Mpc
(Washington 28
Mpc
, Louisiana 68
Mpc
)Slide4
Recent LIGO Noise Spectrum
Initial LIGO, 20
Mpc
Advanced LIGO, 59
Mpc
Design Sensitivity, 138
Mpc
(Laser power = 25 W)
O1 run this summer
Slide5
Short Gamma-Ray Burst
sGRB
Fermi
sGRB is most likely due to merging of Neutron Stars
Inspiral
of NS – NS produces GW, merger produces burst of Gamma-rays
Excellent candidate for coincident detection of GW and Gamma-ray
Overlap
of GW/Gamma-ray in time and location
subthreshold
detection
> 100
sGRBs
observed by Fermi Gamma-Ray Burst Monitor (GBM)
12
Na I detectors in varying orientations, 5 degree position resolution
GW is roughly isotropic, but Gamma-ray is beamed (10 degree opening)
Need sGRB within LIGO horizon (400
Mpc
), and beamed at earthSlide6
LIGO – GBM Coincident Search
GBM coincidence in time and space will help verify the GW event
Followup of GBM with
eg
Palomar Transient Facility
localization
host galaxy, redshift, accurate BNS parameter extraction
Relative timing of Gamma-ray and GW mass of
Graviton
Energetics, beaming, and nature of sGRB
Information on NS Equation of State ?
NS-NS merger: Short Gamma-Ray Burst (sGRB)
LIGO Fermi GBM
GWs Gamma-rays
4
p
FoV
2
p
FoV
100 deg
2
25 deg
2Slide7
Coherent Analysis of GBM Detectors
(L. Blackburn and UAH)
signal
noise
data
Instrument response
source
Evaluate
L
by marginalizing over
source
amplitude, position
r
i
provided by GBM detector model (
Connaughton
, UAH)
Factor
2 gain in SNRSlide8
8
Test of Initial LIGO – GBM coincident analysis
L. Blackburn,
ApJ S 217 (2015)
ASM
GBM
LIGO BNS trigger
LIGO sky localizationSlide9
9
sGRB Precursors and NS EOS
E.
Troja et al, Ap J 723 (2010)
Slide10
NS Crust Resonant Shattering Process
Tsang et al, PRL 108 (2012)
10
Mode Energy
~ 10
47
erg Fracture
Seismic Energy~ 10
46 erg Shattering
Luminosity ~ 10
46-47
erg 0.1 sec
(can see 10
47
erg at ~ 150
Mpc
)
Isotropic (!)
Available Tidal Energy
~ 10
50
ergSlide11
11
Investigating NS Crust Equation of State
f
res
(from GW)
at time of Precursor
NS EoSSlide12
Optimistic
O1 LIGO and sGRB Rates
aLIGO
BNS Detections
sGRB Detections
Typical jet angle ~ 10 degree
beaming factor ~ 100
Thus 3 LIGO BNS detections ~ 0.03 coincident sGRB detection
~ 0.3 (
subthreshold
/GW on jet axis)
Realistic rates likely to be factor 10 lower… look to O2, O3Slide13
O1 LIGO – GBM Search
O1 run around fall 2015
3 months
Hanford and Livingston detector range > 60 MpcPipeline development
Further tests of GBM coherent analysisUse GBM continuous data from every downlink (CTTE)LIGO sky localization: low-latency to enable real-time alerts
Run pipelineAnalyze results and get ready for O2
run at > 100 MpcContinue development of GBM coherent analysis (UAH)