<?xml version='1.0' encoding='UTF-8'?>
<voe:VOEvent xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:voe="http://www.ivoa.net/xml/VOEvent/v2.0" xsi:schemaLocation="http://www.ivoa.net/xml/VOEvent/v2.0 http://www.ivoa.net/xml/VOEvent/VOEvent-v2.0.xsd" version="2.0" role="observation" ivorn="ivo://gwnet/LVC#S231109ap-1-Preliminary">
  <Who>
    <Date>2023-11-09T14:10:15Z</Date>
    <Author>
      <contactName>LIGO Scientific Collaboration, Virgo Collaboration, and KAGRA Collaboration</contactName>
    </Author>
  </Who>
  <What>
    <Param name="Packet_Type" value="150" dataType="int">
      <Description>The Notice Type number is assigned/used within GCN, eg type=150 is an LVC_PRELIMINARY notice</Description>
    </Param>
    <Param name="internal" value="0" dataType="int">
      <Description>Indicates whether this event should be distributed to LSC/Virgo/KAGRA members only</Description>
    </Param>
    <Param name="Pkt_Ser_Num" value="1" dataType="int">
      <Description>A number that increments by 1 each time a new revision is issued for this event</Description>
    </Param>
    <Param name="GraceID" value="S231109ap" ucd="meta.id" dataType="string">
      <Description>Identifier in GraceDB</Description>
    </Param>
    <Param name="AlertType" value="Preliminary" ucd="meta.version" dataType="string">
      <Description>VOEvent alert type</Description>
    </Param>
    <Param name="HardwareInj" value="0" ucd="meta.number" dataType="int">
      <Description>Indicates that this event is a hardware injection if 1, no if 0</Description>
    </Param>
    <Param name="OpenAlert" value="1" ucd="meta.number" dataType="int">
      <Description>Indicates that this event is an open alert if 1, no if 0</Description>
    </Param>
    <Param name="EventPage" value="https://gracedb.ligo.org/superevents/S231109ap/view/" ucd="meta.ref.url" dataType="string">
      <Description>Web page for evolving status of this GW candidate</Description>
    </Param>
    <Param name="Instruments" value="H1,L1" ucd="meta.code" dataType="string">
      <Description>List of instruments used in analysis to identify this event</Description>
    </Param>
    <Param name="FAR" value="8.889399396139197e-06" unit="Hz" ucd="arith.rate;stat.falsealarm" dataType="float">
      <Description>False alarm rate for GW candidates with this strength or greater</Description>
    </Param>
    <Param name="Significant" value="0" ucd="meta.number" dataType="int">
      <Description>Indicates that this event is significant if 1, no if 0</Description>
    </Param>
    <Param name="Group" value="CBC" ucd="meta.code" dataType="string">
      <Description>Data analysis working group</Description>
    </Param>
    <Param name="Pipeline" value="spiir" ucd="meta.code" dataType="string">
      <Description>Low-latency data analysis pipeline</Description>
    </Param>
    <Param name="Search" value="AllSky" ucd="meta.code" dataType="string">
      <Description>Specific low-latency search</Description>
    </Param>
    <Group name="GW_SKYMAP" type="GW_SKYMAP">
      <Param name="skymap_fits" value="https://gracedb.ligo.org/api/superevents/S231109ap/files/bayestar.multiorder.fits,0" ucd="meta.ref.url" dataType="string">
        <Description>Sky Map FITS</Description>
      </Param>
    </Group>
    <Group name="Classification" type="Classification">
      <Param name="BNS" value="0.0" ucd="stat.probability" dataType="float">
        <Description>Probability that the source is a binary neutron star merger (both objects lighter than 3 solar masses)</Description>
      </Param>
      <Param name="NSBH" value="0.00016811135618743917" ucd="stat.probability" dataType="float">
        <Description>Probability that the source is a neutron star-black merger (secondary lighter than 3 solar masses)</Description>
      </Param>
      <Param name="BBH" value="0.0745669182035841" ucd="stat.probability" dataType="float">
        <Description>Probability that the source is a binary black hole merger (both objects heavier than 3 solar masses)</Description>
      </Param>
      <Param name="Terrestrial" value="0.9252649704402285" ucd="stat.probability" dataType="float">
        <Description>Probability that the source is terrestrial (i.e., a background noise fluctuation or a glitch)</Description>
      </Param>
      <Description>Source classification: binary neutron star (BNS), neutron star-black hole (NSBH), binary black hole (BBH), or terrestrial (noise)</Description>
    </Group>
    <Group name="Properties" type="Properties">
      <Param name="HasNS" value="0.6694372251611097" ucd="stat.probability" dataType="float">
        <Description>Probability that at least one object in the binary has a mass that is less than 3 solar masses</Description>
      </Param>
      <Param name="HasRemnant" value="0.0" ucd="stat.probability" dataType="float">
        <Description>Probability that a nonzero mass was ejected outside the central remnant object</Description>
      </Param>
      <Param name="HasMassGap" value="0.00025" ucd="stat.probability" dataType="float">
        <Description>Probability that the source has at least one object between 3 and 5 solar masses</Description>
      </Param>
      <Description>Qualitative properties of the source, conditioned on the assumption that the signal is an astrophysical compact binary merger</Description>
    </Group>
  </What>
  <WhereWhen>
    <ObsDataLocation>
      <ObservatoryLocation id="LIGO Virgo"/>
      <ObservationLocation>
        <AstroCoordSystem id="UTC-FK5-GEO"/>
        <AstroCoords coord_system_id="UTC-FK5-GEO">
          <Time unit="s">
            <TimeInstant>
              <ISOTime>2023-11-09T14:09:51Z</ISOTime>
            </TimeInstant>
          </Time>
        </AstroCoords>
      </ObservationLocation>
    </ObsDataLocation>
  </WhereWhen>
  <Description>Report of a candidate gravitational wave event</Description>
  <How>
    <Description>Candidate gravitational wave event identified by low-latency analysis</Description>
    <Description>H1: LIGO Hanford 4 km gravitational wave detector</Description>
    <Description>L1: LIGO Livingston 4 km gravitational wave detector</Description>
  </How>
</voe:VOEvent>

<?xml version='1.0' encoding='UTF-8'?>
<voe:VOEvent xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:voe="http://www.ivoa.net/xml/VOEvent/v2.0" xsi:schemaLocation="http://www.ivoa.net/xml/VOEvent/v2.0 http://www.ivoa.net/xml/VOEvent/VOEvent-v2.0.xsd" version="2.0" role="observation" ivorn="ivo://gwnet/LVC#S231109ap-2-Preliminary">
  <Who>
    <Date>2023-11-09T14:14:50Z</Date>
    <Author>
      <contactName>LIGO Scientific Collaboration, Virgo Collaboration, and KAGRA Collaboration</contactName>
    </Author>
  </Who>
  <What>
    <Param name="Packet_Type" value="150" dataType="int">
      <Description>The Notice Type number is assigned/used within GCN, eg type=150 is an LVC_PRELIMINARY notice</Description>
    </Param>
    <Param name="internal" value="0" dataType="int">
      <Description>Indicates whether this event should be distributed to LSC/Virgo/KAGRA members only</Description>
    </Param>
    <Param name="Pkt_Ser_Num" value="2" dataType="int">
      <Description>A number that increments by 1 each time a new revision is issued for this event</Description>
    </Param>
    <Param name="GraceID" value="S231109ap" ucd="meta.id" dataType="string">
      <Description>Identifier in GraceDB</Description>
    </Param>
    <Param name="AlertType" value="Preliminary" ucd="meta.version" dataType="string">
      <Description>VOEvent alert type</Description>
    </Param>
    <Param name="HardwareInj" value="0" ucd="meta.number" dataType="int">
      <Description>Indicates that this event is a hardware injection if 1, no if 0</Description>
    </Param>
    <Param name="OpenAlert" value="1" ucd="meta.number" dataType="int">
      <Description>Indicates that this event is an open alert if 1, no if 0</Description>
    </Param>
    <Param name="EventPage" value="https://gracedb.ligo.org/superevents/S231109ap/view/" ucd="meta.ref.url" dataType="string">
      <Description>Web page for evolving status of this GW candidate</Description>
    </Param>
    <Param name="Instruments" value="H1,L1" ucd="meta.code" dataType="string">
      <Description>List of instruments used in analysis to identify this event</Description>
    </Param>
    <Param name="FAR" value="8.889399396139197e-06" unit="Hz" ucd="arith.rate;stat.falsealarm" dataType="float">
      <Description>False alarm rate for GW candidates with this strength or greater</Description>
    </Param>
    <Param name="Significant" value="0" ucd="meta.number" dataType="int">
      <Description>Indicates that this event is significant if 1, no if 0</Description>
    </Param>
    <Param name="Group" value="CBC" ucd="meta.code" dataType="string">
      <Description>Data analysis working group</Description>
    </Param>
    <Param name="Pipeline" value="spiir" ucd="meta.code" dataType="string">
      <Description>Low-latency data analysis pipeline</Description>
    </Param>
    <Param name="Search" value="AllSky" ucd="meta.code" dataType="string">
      <Description>Specific low-latency search</Description>
    </Param>
    <Group name="GW_SKYMAP" type="GW_SKYMAP">
      <Param name="skymap_fits" value="https://gracedb.ligo.org/api/superevents/S231109ap/files/bayestar.multiorder.fits,1" ucd="meta.ref.url" dataType="string">
        <Description>Sky Map FITS</Description>
      </Param>
    </Group>
    <Group name="Classification" type="Classification">
      <Param name="BNS" value="0.0" ucd="stat.probability" dataType="float">
        <Description>Probability that the source is a binary neutron star merger (both objects lighter than 3 solar masses)</Description>
      </Param>
      <Param name="NSBH" value="0.00016811135618743917" ucd="stat.probability" dataType="float">
        <Description>Probability that the source is a neutron star-black merger (secondary lighter than 3 solar masses)</Description>
      </Param>
      <Param name="BBH" value="0.0745669182035841" ucd="stat.probability" dataType="float">
        <Description>Probability that the source is a binary black hole merger (both objects heavier than 3 solar masses)</Description>
      </Param>
      <Param name="Terrestrial" value="0.9252649704402285" ucd="stat.probability" dataType="float">
        <Description>Probability that the source is terrestrial (i.e., a background noise fluctuation or a glitch)</Description>
      </Param>
      <Description>Source classification: binary neutron star (BNS), neutron star-black hole (NSBH), binary black hole (BBH), or terrestrial (noise)</Description>
    </Group>
    <Group name="Properties" type="Properties">
      <Param name="HasNS" value="0.6694372251611097" ucd="stat.probability" dataType="float">
        <Description>Probability that at least one object in the binary has a mass that is less than 3 solar masses</Description>
      </Param>
      <Param name="HasRemnant" value="0.0" ucd="stat.probability" dataType="float">
        <Description>Probability that a nonzero mass was ejected outside the central remnant object</Description>
      </Param>
      <Param name="HasMassGap" value="0.00025" ucd="stat.probability" dataType="float">
        <Description>Probability that the source has at least one object between 3 and 5 solar masses</Description>
      </Param>
      <Description>Qualitative properties of the source, conditioned on the assumption that the signal is an astrophysical compact binary merger</Description>
    </Group>
  </What>
  <WhereWhen>
    <ObsDataLocation>
      <ObservatoryLocation id="LIGO Virgo"/>
      <ObservationLocation>
        <AstroCoordSystem id="UTC-FK5-GEO"/>
        <AstroCoords coord_system_id="UTC-FK5-GEO">
          <Time unit="s">
            <TimeInstant>
              <ISOTime>2023-11-09T14:09:51Z</ISOTime>
            </TimeInstant>
          </Time>
        </AstroCoords>
      </ObservationLocation>
    </ObsDataLocation>
  </WhereWhen>
  <Description>Report of a candidate gravitational wave event</Description>
  <How>
    <Description>Candidate gravitational wave event identified by low-latency analysis</Description>
    <Description>H1: LIGO Hanford 4 km gravitational wave detector</Description>
    <Description>L1: LIGO Livingston 4 km gravitational wave detector</Description>
  </How>
  <Citations>
    <EventIVORN cite="supersedes">ivo://gwnet/LVC#S231109ap-1-Preliminary</EventIVORN>
    <Description>Initial localization is now available (preliminary)</Description>
  </Citations>
</voe:VOEvent>