IceCube-211023A
GCN Circular 30957
Subject
IceCube-211023A - IceCube observation of a high-energy neutrino candidate track-like event
Date
2021-10-23T09:47:02Z (4 years ago)
From
Dr. Massimiliano Lincetto at Ruhr-Universitaet Bochum <lincetto@astro.rub.de>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
On 2021/10/23 at 08:31:18.31 UT IceCube detected a track-like event with a moderate probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_Bronze alert stream. The average astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 3.2 events per year due to atmospheric backgrounds. The IceCube detector was in a normal operating state at the time of detection.
After the initial automated alert (https://gcn.gsfc.nasa.gov/notices_amon_g_b/135832_55176071.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:
Date: 2021/10/23
Time: 08:31:18.31 UT
RA: +253.30 (+1.05 / -1.08 deg 90% PSF containment) J2000
Dec: -1.72 (+1.16 / -1.11 deg 90% PSF containment) J2000
We encourage follow-up by ground and space-based instruments to help identify a possible astrophysical source for the candidate neutrino.
One gamma-ray source, 4FGL J1653.6-0158, is located within the 90% of the error region, 0.27 deg away from the best-fit position. The source is associated with the pulsar PSR J1653-0158.
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu
GCN Circular 30971
Subject
IceCube-211023A: No neutrino counterpart detected with ANTARES
Date
2021-10-24T12:37:26Z (4 years ago)
From
Antoine Kouchner at ANTARES Collaboration <kouchner@apc.in2p3.fr>
Alexis Coleiro (APC/Universite de Paris) and Damien Dornic (CPPM/CNRS) on behalf of the ANTARES Collaboration.
Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported bronze track event IceCube-211023A (GCN #30957 <https://gcn.gsfc.nasa.gov/gcn3/30957.gcn3>). The reconstructed origin was slightly above the horizon for ANTARES at the time of the alert (+0.8 degrees).
No horizontal muon neutrino candidate events were recorded within 90% error box of the IceCube event during a +/- 1h time-window centered on the IceCube event time, and over which the potential source remained visible half of the time. This leads to a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of about 12 GeV.cm^-2 over the energy range 3 TeV ��� 3 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and 48 GeV.cm^-2 (600 GeV - 300 TeV) for an E^-2.5 spectrum.
A search over an extended time window of +/- 1 day has also yielded no detection (51% visibility).
ANTARES <http://antares.in2p3.fr/> is the largest undersea neutrino detector (Mediterranean Sea) and it is primarily sensitive to astrophysical neutrinos in the TeV-PeV energy range. At 10 TeV, the median angular resolution for muon neutrinos is about 0.5 degrees. In the range 1-100 TeV ANTARES has a competitive sensitivity to this position in the sky.
GCN Circular 30978
Subject
Fermi-LAT Gamma-ray Observations of IceCube-211023A
Date
2021-10-24T20:50:39Z (4 years ago)
From
Simone Garrappa at DESY <simone.garrappa@desy.de>
S. Garrappa (DESY-Zeuthen), S. Buson (Univ. of Wuerzburg) and R. de
Menezes (Univ. of Wuerzburg, Univ. of Sao Paulo) on behalf of the
Fermi-LAT collaboration:
We report an analysis of observations of the vicinity of the high-energy
IC211023A neutrino event (GCN 30957) with all-sky survey data from the
Large Area Telescope (LAT), on board the Fermi Gamma-ray Space
Telescope. The IceCube event was detected on 2021-10-23 at 08:31:18.31
UT (T0) with J2000 position RA = 253.30 (+1.05,-1.08) deg, Decl. = -1.72
(+1.16, -1.11) deg (90% PSF containment). One cataloged gamma-ray (>100
MeV) source is located within the 90% IC211023A localization region.
This is 4FGL J1653.6-0158 (4FGL-DR2, The Fermi-LAT collaboration 2020,
ApJS, 247, 33), identified as PSR J1653-0158 (Nieder et al. 2020 ApJL
202, 46). Based on a preliminary analysis of the LAT data over the
timescales of 1-day and 1-month prior to T0, this object is not
significantly detected (> 5 sigma).
We searched for intermediate (days to years) timescale emission from a
new gamma-ray transient source. Preliminary analysis indicates no
significant (> 5 sigma) new excess emission (> 100 MeV) at the IC211023A
best-fit position. Assuming a power-law spectrum (photon index = 2.0
fixed) for a point source at the IC211023A best-fit position, the >100
MeV flux upper limit (95% confidence) is < 8.8e-10 ph cm^-2 s^-1 for
~13-years (2008-08-04 to 2021-10-23 UTC), and < 1.6e-8 (< 1.9e-7) ph
cm^-2 s^-1 for a 1-month (1-day) integration time before T0.
Since Fermi normally operates in an all-sky scanning mode, regular
monitoring of this source will continue. For these observations the
Fermi-LAT contact persons are S. Garrappa (simone.garrappa at desy.de)
and S. Buson (sara.buson at uni-wuerzburg.de).
The Fermi-LAT is a pair conversion telescope designed to cover the
energy band from 20 MeV to greater than 300 GeV. It is the product of an
international collaboration between NASA and DOE in the U.S. and many
scientific institutions across France, Italy, Japan and Sweden.
GCN Circular 30999
Subject
IceCube-211023A: Upper limits from a search for additional neutrino events in IceCube
Date
2021-10-25T20:00:34Z (4 years ago)
From
Alex Pizzuto at ICECUBE/U of Wisconsin <pizzuto@wisc.edu>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
IceCube has performed a search [1] for additional track-like muon neutrino events arriving from the direction of IceCube-211023A (https://gcn.gsfc.nasa.gov/gcn3/30957.gcn3) in a time range of 1000 seconds centered on the alert event time (2021-10-23 08:22:58.310 UTC to 2021-10-23 08:39:38.310 UTC) during which IceCube was collecting good quality data. Excluding the event that prompted the alert, zero track-like events are found within the 90% containment region of IceCube-211023A.
The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-211023A is 1.5e-01 GeV cm^-2 in a 1000 second time window. 90% of events IceCube would detect from a source at this declination with an E^-2.5 spectrum have energies in the approximate range between 3e+02 GeV and 2e+05 GeV.
A subsequent search was performed including 2 days of data centered on the alert
event time (2021-10-22 08:31:18.310 UTC to 2021-10-24 08:31:18.310 UTC). In this case, we report a p-value of 0.09, consistent with no significant excess of track events. The IceCube sensitivity to neutrino point sources with an E^-2.5 spectrum (E^2 dN/dE at 1 TeV) within the locations spanned by the 90% spatial containment region of IceCube-211023A is 1.6e-01 GeV cm^-2 in a 2 day time window.
The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at
the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can
be reached at roc@icecube.wisc.edu<mailto:roc@icecube.wisc.edu>.
[1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)
GCN Circular 31117
Subject
IceCube-211023A: not observable by Fermi-GBM
Date
2021-11-24T20:38:04Z (4 years ago)
From
Cori Fletcher at USRA <cfletcher@usra.edu>
C. Fletcher (USRA) reports on behalf of the Fermi-GBM team:
For the IceCube high-energy neutrino candidate event IceCube-211023A
(GCN 30957), the reported position:
RA: +253.30 (+1.05 / -1.08 deg 90% PSF containment) J2000
Dec: -1.72 (+1.16 / -1.11 deg 90% PSF containment) J2000
was occulted by the Earth for Fermi-GBM from approximately from 0.1 minutes
prior until 34.4 minutes after event time. Therefore, the GBM
observations are not constraining for prompt gamma-ray emission.