The EventTable class comes with a fetch_open_data()
method that queries the Gravitational-Wave Open Science Center (GWOSC) database
for events and their parameters associated with one of the catalogue event
releases.
Note
For more details on the GWOSC catalogues, see https://www.gw-openscience.org/catalog/.
The simplest query just requires the catalogue name, and will return all parameters for all events in the catalogue:
>>> from gwpy.table import EventTable
>>> t = EventTable.fetch_open_data("GWTC-1-confident")
>>> print(t)
name E_rad L_peak ... tc utctime
8.98755e+16 m2 solMass / s2 1e+56 erg / s ...
-------- --------------------------- ------------- ... ------------ ----------
GW150914 3.1 3.6 ... 1126259462.4 09:50:45.4
GW151012 1.5 3.2 ... 1128678900.4 09:54:43.4
GW151226 1.0 3.4 ... 1135136350.6 03:38:53.6
GW170104 2.2 3.3 ... 1167559936.6 10:11:58.6
GW170608 0.9 3.5 ... 1180922494.5 02:01:16.5
GW170729 4.8 4.2 ... 1185389807.3 18:56:29.3
GW170809 2.7 3.5 ... 1186302519.8 08:28:21.8
GW170814 2.7 3.7 ... 1186741861.5 10:30:43.5
GW170817 0.04 0.1 ... 1187008882.4 12:41:04.4
GW170818 2.7 3.4 ... 1187058327.1 02:25:09.1
GW170823 3.3 3.6 ... 1187529256.5 13:13:58.5
The full list of available columns can be queried as follows:
>>> print(t.info)
<EventTable length=11>
name dtype unit
---------- ------- ---------------------------
name str8
E_rad float64 8.98755e+16 m2 solMass / s2
L_peak float64 1e+56 erg / s
a_final float64
chi_eff float64
distance float64 Mpc
far_cwb str32 1 / yr
far_gstlal float64 1 / yr
far_pycbc str32 1 / yr
mass1 float64 solMass
mass2 float64 solMass
mchirp float64 solMass
mfinal float64 solMass
redshift float64
sky_size float64 deg2
snr_cwb str32
snr_gstlal float64
snr_pycbc str32
tc float64
utctime str10
The columns returned can be selected using the column keyword,
and mathematical selection filters can be applied on-the-fly
using the selection keyword:
>>> t = EventTable.fetch_open_data(
... "GWTC-1-confident",
... selection="mass1 < 4",
... columns=["name", "mass1", "mass2", "distance"],
... )
>>> print(t)
name mass1 mass2 distance
solMass solMass Mpc
-------- ------- ------- --------
GW170817 1.46 1.27 40.0
For more information on filtering, see Filtering tables.
For some examples of visualising the catalogues, see Plotting an EventTable in a scatter and Plotting an EventTable in a histogram.
The EventTable returned by fetch_open_data() includes an
index based on the 'name' column, so you can directly access rows in the
table based on their name:
>>> t = EventTable.fetch_open_data(
... "GWTC-1-confident",
... columns=["name", "utctime", "mass1", "mass2", "distance"],
... )
>>> print(t.loc["GW170817"])
name utctime mass1 mass2 distance
solMass solMass Mpc
-------- ---------- ------- ------- --------
GW170817 12:41:04.4 1.46 1.27 40.0