S5 Compact Binary Coalescence Hardware Injections
During LIGO's 5th Science Run (S5), simulated signals were added to the
LIGO detectors for testing and calibration. The simulated signals are
known as hardware injections, because they were created by manipulating
mirrors in the arms of the interferometers. Times of hardware injections
are marked in LIGO data files by injection data quality channels. See the
injection bit mask
Compact Binary Coalescence Injections
Compact Binary Coalescence (CBC) injections were added at planned
times throughout S5. Each CBC injection used a Post-Newtonian waveform
to approximate the signal expected from the inspiral of a binary
neutron star system, a neutron star with a black hole, or a binary
black hole. A spectrogram of a sample injetion can be seen in the image
on this page.
In addition to the CBC injections noted in the tables below, there were CBC "blind injections" in S5:
CBC Blind Injection: 873739911
Blind Injection Tests: 865120335 and 865143706
See also this introduction to blind injections.
Tables of Injections
The links below provide a list of CBC hardware injections executed during
S5. Each injection is listed with the following information:
- GPS: The approximate GPS time of the end of the injection, or the "merger" time, in GPS seconds
- IFO: The interferometer
- M1 / M2: The mass, in solar units, of each compact object
- Distance: The distance to the simulated source in Mpc.
- Log: A log message indicating the success of the injection
- Exp_SNR: The expected SNR of the injection based on the planned input parameters
and a measurement of the detecotr PSD near the injection time.
- Rec_SNR: The recovered SNR of the injection, as measured in the GWOSC data set. SNRs from
1-4 are typical for times with no signal.
The expected SNR and actual SNR were calculated using 64 seconds of data
centered on the planned injection time. In cases where this 64 seconds of data included
some time not in science mode, this calculation was not performed. It is possible that
an injection or a partial injection exists in the data at some of these times. See the
Technical Details page
for more information.
Links to tables of injections:
Timeline Segment Lists of Injections
In addition to the log files shown above, information about injection times is available in segment lists
from the Timeline
- The HW segment lists contain all Burst, CBC, and Stochastic injection times:
- The HW segment lists contain a small number of injections not noted in the Burst or CBC logs:
- The HW_CBC segment lists contains a list CBC injections, but is only defined for the first year of the S5 run.
Additional Injection Lists
More information on CBC hardware injections is avaialable on the Technical Details