S6 Compact Binary Coalescence Hardware Injections
During LIGO's 6th Science Run (S6), 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 S6. Each CBC injection used a waveform
to approximate the signal expected from the inspiral, merger, and
ringdown of a binary
neutron star system, a neutron star with a black hole, or a binary
black hole. A spectrogram of a sample injection can be seen in the image
on this page.
Tables of Injections
The links below provide a list of CBC hardware injections executed during
S6. Each injection is listed with the following information:
- GPS: The GPS time of the end of the injection, or the "merger" time, in GPS seconds
- Mass1 / Mass2: The mass, in solar units, of each compact object
- Dist: The distance to the simulated source in Mpc.
- SNR_exp: The expected SNR of the injection.
- SNR_act: The recovered SNR of the injection, as described in
Shannon Wang's project report.
SNRs from 1-5 are typical for times with no signal.
The expected SNR and actual SNR were calculated using 100 seconds of data
centered on the planned injection time. In cases where these 100 seconds of data included
some time not in science mode, a smaller time window was used.
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:
Lists of S6 CBC injections: H1
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_CBC segment lists contain the CBC injections
- Discrepencies between the Timeline and Parameter lists are notes here:
A number of CBC blind injections
and blind injection tests were made
during S6. Their times are listed below. In addition, the approximate times of blind injections are listed in the
tables of injections, with 0's listed for all other parameters.
- [954431951, 954432079]
- [966378206, 966378309]
- [967021118, 967021221]
- [967515158, 967515261]
- [967818859, 967818962]
- [968654461, 968654564]
The last in this list, on 2010 Sept 16, is the subject of an earlier open data release by LIGO,
GW100916 or Big Dog
Additional Injection Lists
More information on CBC hardware injections is avaialable on the Technical Details