IceCube-200620A
GCN Circular 27997
Subject
IceCube-200620A - IceCube observation of a high-energy neutrino candidate track-like event
Date
2020-06-20T05:57:26Z (5 years ago)
From
Marcos Santander at U. Alabama/IceCube <jmsantander@ua.edu>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
On 2020-06-20 at 03:03:32.282 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 threshold astrophysical neutrino purity for Bronze alerts is 30%. This alert has an estimated false alarm rate of 2.321 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/134207_33533447.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:
Date: 2020-06-20
Time: 03:03:32.28 UT
RA: 162.11 (+0.64 -0.95 deg 90% PSF containment) J2000
Dec: 11.95 (+0.63 -0.48 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.
There are no Fermi 4FGL or 3FHL catalog sources in the 90% uncertainty region. The nearest gamma-ray source in either catalog is 4FGL J1041.0+1342 at RA: 160.27 deg, Dec: 13.71 deg (J2000), 2.51 deg away from the best-fit event position.
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 28002
Subject
IceCube-200620A: No ANTARES neutrino counterpart
Date
2020-06-21T06:42:25Z (5 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. <br>
Using data from the ANTARES detector, we have performed a follow-up analysis of the recently reported single track-like event IceCube-200620A (GCN 27997<https://gcn.gsfc.nasa.gov/gcn3/27997.gcn3 <https://gcn.gsfc.nasa.gov/gcn3/27997.gcn3>>). The original reconstructed origin was 31.9 degrees below the horizon for ANTARES. <br>
No up-going muon neutrino candidate events were recorded in a 3 deg cone around the location of the IceCube event coordinates (accounting for the reported uncertainties) during a +/- 1h time-window centered on the IceCube event time, and over which the potential source remained visible all time. <br>
This leads to a preliminary 90% confidence level upper limit on the muon-neutrino fluence from a point source of about 15 GeV.cm^-2 over the energy range 5 TeV ���4 PeV (the range corresponding to 5-95% of the detectable flux) for an E^-2 power-law spectrum, and about 30 GeV.cm^-2 (810 GeV - 405 TeV) for an E^-2.5 spectrum.
A search over an extended time window of +/- 1 day has also yielded no detection (44% visibility). <br>
ANTARES <http://antares.in2p3.fr/ <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 28004
Subject
Fermi-LAT Gamma-ray Observations of IceCube-200620A
Date
2020-06-21T12:27:44Z (5 years ago)
From
Simone Garrappa at DESY <simone.garrappa@desy.de>
**
*S. Garrappa (DESY-Zeuthen) and S. Buson (Univ. of Wuerzburg) on behalf
of the Fermi-LAT collaboration:*
*
We report an analysis of observations of the vicinity of the high-energy
IC200620A neutrino event (GCN 27997) 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 2020-06-20 at 03:03:32.28
UT (T0) with J2000 position RA =162.11 (+0.64 -0.95) deg, Decl. = 11.95
(+0.63 -0.48) deg 90% PSF containment. No cataloged >100 MeV gamma-ray
sources (The Fermi-LAT Collaboration 2019, arXiv:1902.10045) are located
within the 90% IC200620A localization error.
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
IC200620A best-fit position. Assuming a power-law spectrum (photon index
= 2.0 fixed) for a point source at the IceCube best-fit position, the
>100 MeV flux upper limit (95% confidence) is < 1.4e-10 ph cm^-2 s^-1
for ~11-years (2008-08-04 / 2020-06-20 UTC), < 1.7e-8 (< 1.6e-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
<http://desy.de/>) and S. Buson (sara.buson at uni-wuerzburg.de
<http://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 28005
Subject
IceCube-200620A: One Candidate Counterpart from the Zwicky Transient Facility
Date
2020-06-21T19:16:19Z (5 years ago)
From
Simeon Reusch at DESY <simeon.reusch@desy.de>
Simeon Reusch, Robert Stein and Anna Franckowiak (DESY) report:
On behalf of the Zwicky Transient Facility (ZTF) and Global Relay of
Observatories Watching Transients Happen (GROWTH) collaborations:
We observed the localization region of the neutrino event
IceCube-200620A (Santander et. al, GCN 27997) with the Palomar 48-inch
telescope, equipped with the 47 square degree ZTF camera (Bellm et al.
2019, Graham et al. 2019). We started observations in the r-band
beginning at 2020-06-21T04:49 UTC, approximately 25.8 hours after event
time. We covered 1.2 sq deg, corresponding to 100.0% of the reported
localization region (this estimate does not account for chip gaps). Each
exposure was 300s with a typical depth of 21.0 mag.
The images were processed in real-time through the ZTF reduction and
image subtraction pipelines at IPAC to search for potential counterparts
(Masci et al. 2019). AMPEL (Nordin et al. 2019) was used to search the
alerts database for candidates. We reject stellar sources (Tachibana and
Miller 2018) and moving objects, and apply machine learning algorithms
(Mahabal et al. 2019). We are left with the following high-significance
transient candidate by our pipeline, lying within the 90.0% localization
of the skymap.
+---------------------------------------------------------------------------------+
| ZTF Name | IAU Name | RA (deg) | DEC (deg) | Filter | Mag
| MagErr |
+---------------------------------------------------------------------------------+
| ZTF20abgvabi | AT 2020ncr | 162.5306820 | +12.1462203 | r | 20.67
| 0.10 |
+---------------------------------------------------------------------------------+
AT 2020ncr has a faint host with a SDSS photometric redshift estimate of
z=0.51 +/- 0.09. This would result in an estimated absolute magnitude of
-21.7. There have been optical pre-detections up to 120 days prior to
neutrino arrival time. As the nature of the transient is unclear,
spectroscopic follow-up is recommended.
ZTF and GROWTH are worldwide collaborations comprising Caltech, USA;
IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA;
DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech,
Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd,
Australia.
ZTF acknowledges the generous support of the NSF under AST MSIP Grant No
1440341.
GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949.
Alert distribution service provided by DIRAC@UW (Patterson et al. 2019).
Alert database searches are done by AMPEL (Nordin et al. 2019).
GCN Circular 28006
Subject
IceCube-200620A: not observable by Fermi-GBM
Date
2020-06-21T19:29:15Z (5 years ago)
From
Cori Fletcher at USRA <cfletcher@usra.edu>
C. Fletcher (USRA) reports on behalf of the Fermi-GBM team:
At the time of the neutrino candidate IceCube-200620A
(GCN 27997), Fermi was passing through the South Atlantic
Anomaly from 17.6 minutes prior until 4.1 minutes after the trigger
time; therefore the GBM detectors were disabled.
GCN Circular 28007
Subject
IceCube-200620A: MASTER previous detection of ZTF20abgvabi/AT2020ncr
Date
2020-06-21T22:59:26Z (5 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy, N.Tiurina, K.Zhirkov, P.Balanutsa,A.Kuznetsov,F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov(Lomonosov Moscow State University, SAI, Physics Department),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix Aguilar OAFA),
H. Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev (Irkutsk State University, API),
A. Gabovich, Yu. Sergienko, V.Yurkov (Blagoveschensk Educational State University)
MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
started IceCube-200620A inspection (The IceCube Collaboration GCN 27997)
8560 sec after trigger time at 2020-06-20 16:32:52 UT (Lipunov et al. GCN 28001, see cover map and
error-box altitude at alert time and inspect time at
https://master.sai.msu.ru/site/master2/observ.php?id=1386385 )
ZTF candidate ZTF20abgvabi/AT 2020ncr with
RA,Dec(2000)=162.5306820 +12.1462203 (Reusch et al. GCN 28005)
presents at MASTER archive images on 2015-12-25 (60s exposition).
MASTER database (2006-2020) analysis will be continued.
GCN Circular 28009
Subject
IceCube-200620A: INTEGRAL was inactive at the time of the event
Date
2020-06-22T14:04:20Z (5 years ago)
From
Volodymyr Savchenko at ISDC,U of Geneve <savchenk@in2p3.fr>
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
S. Mereghetti (INAF IASF-Milano, Italy)
J. Rodi (IAPS-Roma, Italy)
A. Coleiro (APC, France)
on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration
The INTEGRAL spacecraft has a highly elliptical orbit and the
instruments are not acquiring science data during perigee passage,
every 2.6 days to prevent radiation-induced damages. Unfortunately, at
the time of the IceCube-200620A (2020-06-20 03:03:32, GCN27997) the spacecraft was
preparing to the start the observations after the perigee passage
between the orbits number 2241 and 2242 and no scientific instrument
data are available between 2020-06-19T22:20:06 and 2020-06-20T08:40:00.
GCN Circular 28010
Subject
IceCube-200620A: Upper limits from a search for additional neutrino events in IceCube
Date
2020-06-22T14:09:01Z (5 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 for additional track-like muon neutrino events arriving
from the direction of IceCube-200620A (https://gcn.gsfc.nasa.gov/gcn3/27997.gcn3) in a time
range of 2 days centered on the alert event time (2020-06-19 03:03:32.28 UTC to 2020-06-21 03:03:32.28 UTC) during which IceCube was collecting good quality data. Excluding the
event that prompted the alert, one additional track-like event is found in spatial coincidence
with the 90% containment region of IceCube-200620A. We find that these data are consistent with atmospheric background expectations, with a p-value of 1.0. We accordingly derive a time-integrated muon-neutrino flux upper limit at the alert position of E^2 dN/ dE = 4.0 x 10^-5 TeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum are approximately between 1 TeV and 1 PeV.
A subsequent search was performed to include the month of data prior to the alert event (2020-05-20 03:03:32.28 UTC to 2020-06-21 03:03:32.28 UTC). In this case, we report a p-value of 1.0, consistent with no significant excess of track-like events, and a corresponding time-integrated muon-neutrino flux upper limit assuming an E^-2 spectrum (E^2 dN/dE) of
6.6 x 10^-5 TeV cm^-2 at the 90% CL.
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>.
GCN Circular 28014
Subject
IceCube-200620A: No significant detection in HAWC
Date
2020-06-23T13:37:01Z (5 years ago)
From
Hugo Ayala at Pennsylvania State University <hgayala@psu.edu>
Hugo Ayala (Penn State) reports on behalf of the HAWC
collaboration (http://www.hawc-observatory.org/collaboration):
On 2020/06/20 03:03:32 UTC, the IceCube collaboration reported a
track-like very-high-energy event that has a high probability of
being an astrophysical neutrino, IceCube-200620A. Location is at
RA: 162.11 (+0.64/-0.95 deg 90% PSF containment) J2000
Dec: 11.95 (+0.63/-0.48 deg 90% PSF containment) J2000
(GCN circular 27997).
We performed two types of analyses for the follow-up. The first is for
a steady source in archival data and the second is a search for a
transient source. We assume a power-law spectrum with an index of -2.3
for both analyses.
Search for a steady source in archival data:
The archival data spans from November 2014 to May 2018. We searched
inside the reported IceCube error region.
The most significant location, with p-value 2.17e-2 (1.79e-1 post-trials),
is at RA 161.76 deg, Dec +12.02 deg (��0.26 deg 68% containment) J2000.
We set a time-integrated 95% CL upper limit on gamma rays at the
maximum position of:
E^2 dN/dE = 2.09e-13 (E/TeV)^-0.3 TeV.cm^-2.s^-1
Search for a transient source.
Since the event was not in our field of view at the time reported,
we report the combined result for the transits before and after the
IceCube event.
Data acquisition started on 2020/06/19 02:14:06 UTC and ended
2020/06/21 02:29:12 UTC.
The most significant location, with p-value 1.99E-3 (1.77E-2 post-trials),
is at RA 162.03 deg, Dec +11.38 deg (��0.46 deg 68% containment) J2000.
We set a time-integrated 95% CL upper limit at the position of
maximum significance of:
E^2 dN/dE = 9.05E-12 (E/TeV)^-0.3 TeV.cm^-2.s^-1
HAWC is a very-high-energy gamma-ray observatory operating in Central
Mexico at latitude 19 deg. north. Operating day and night with over
95% duty cycle, HAWC has an instantaneous field of view of 2 sr and
surveys 2/3 of the sky every day. It is sensitive to gamma rays from
300 GeV to 100 TeV.