IceCube-231211A
GCN Circular 35414
Subject
IceCube-231211A: GRANDMA observations of PKS2047+098
Date
2023-12-22T17:06:57Z (2 years ago)
From
Thierry Pradier at IPHC/University of Strasbourg <tpradier@km3net.de>
Via
Web form
M. Prouza, S. Karpov, M. Mašek (FZU), C. Andrade (UMN), S. Antier (OCA/Artemis), M. Coughlin (UMN), P.A. Duverne (APC), P. Hello (IJCLAB), I. Tosta e Melo (UniCT-DFA), T. Pradier (Unistra/IPHC), D. Turpin (CEA),
report on behalf of the GRANDMA collaboration:
We observed the field of PKS2047+098 after the detection of 2 IceCube high-energy neutrino candidates (GCN 35328, 35332), and the report of an increased gamma-ray activity for this Blazar by Fermi-LAT (GCN 35329). Master-Net reported upper limits for the considered errorbox soon after the IceCube alert (GCN 35321).
Imaging with FRAM-CTA-N telescope of the GRANDMA collaboration in the r- and v-bands, we obtained R > 18.3 and V > 18.6 (5 sigma) on 2023-12-14T20:11:42 and 2023-12-14T20:13:20 with 19x90s exposure.
Followup will continue in the forthcoming weeks.
GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518).
GCN Circular 35332
Subject
IceCube-231211A: Upper limits from a search for additional neutrino events in IceCube
Date
2023-12-13T22:08:40Z (2 years ago)
From
Jessie Thwaites at IceCube/U Wisc-Madison <thwaites@wisc.edu>
Via
Web form
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-231211A (https://gcn.nasa.gov/circulars/35328) in a time range of 1000 seconds centered on the alert event time (2023-12-11 00:39:11.790 UTC to 2023-12-11 00:55:51.790 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-231211A. 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-231211A is 1.3e-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 energy range between 2e+02 GeV and 1e+05 GeV.
A subsequent search was performed including 2 days of data centered on the alert event time (2023-12-10 00:47:31.790 UTC to 2023-12-12 00:47:31.790 UTC). One track-like event is found to be within the 90% contour of the alert event. Its properties are shown in the table below. In this case, we report a p-value of 0.02, 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-231211A is 1.5e-01 GeV cm^-2 in a 2 day time window.
dt(s) RA(deg) Dec(deg) Angular uncertainty(deg)
-----------------------------------------------------------------------------------------------
64664 311.73 10.06 1.03
where:
dt = Time of track event minus time of alert event (sec)
Angular uncertainty = Angular uncertainty of track event: the radius of a circle
representing 90% CL containment by area
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.
[1] IceCube Collaboration, R. Abbasi et al., ApJ 910 4 (2021)
GCN Circular 35329
Subject
Fermi-LAT detection of increased gamma-ray activity of blazar PKS 2047+098, located inside the IceCube-231211A error region
Date
2023-12-12T21:39:38Z (2 years ago)
From
Sara Buson at Univ. of Wurzburg <sara.buson@gmail.com>
Via
Web form
L. Pfeiffer (Univ. of Wuerzburg), S. Buson (Univ. of Wuerzburg), S. Garrappa (Weizmann Institute of Science), C. Bartolini (INFN Bari) and J. Sinapius (DESY) on behalf of the Fermi-LAT collaboration:
We report an analysis of observations of the vicinity of the IC231211A high-energy neutrino event (GCN 35328) 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 23-12-11 at 00:47:31.79 UT (T0) with J2000 position RA = 311.48 (+1.15, -2.33) deg, Decl. = +10.28 (+0.67, -0.68) deg (90% PSF containment). There are three gamma-ray sources (>100 MeV; 4FGL-DR4, The Fermi-LAT collaboration 2023, arXiv:2307.12546) located within the 90% IC231211A localization region. These are the blazar of uncertain type 4FGL J2044.0+1036 (a.k.a. NVSS J204351+103406) at a distance of roughly 0.57 degree from the best-fit localization and the pulsar 4FGL J2047.3+1051 at a distance of roughly 0.68 degree. Based on a preliminary analysis of the LAT data over the timescales of 1-day and 1-month prior to T0, these objects are not significantly detected (> 5 sigma).
The third gamma-ray catalogued source found within the 90% event localisation is the BL Lac object 4FGL J2049.9+1002 (a.k.a. PKS 2047+098, at unknown redshift) at a distance of roughly 1.01 degree. The preliminary analysis indicates that this gamma-ray source is undergoing a prolonged, enhanced activity state. The 3-month-binned gamma-ray light curve shows activity over multiple years. Its gamma-ray flux has increased in recent years and is currently higher than what was observed in the previous 15 years of LAT monitoring. The high state began about nine months ago. During the last 3 months, i.e. 3-month integration time before T0, the observed flux (E>100 MeV) of 4FGL J2049.9+1002 is (8.40 +/- 0.80) x 10^-8 photons cm^-2 s^-1 (statistical uncertainty only), more than 3 times greater than the average flux (2.3 +/- 0.2) x 10^-8 photons cm^-2 s^-1 reported in the 4FGL-DR4. Based on a preliminary analysis of the LAT data over the timescale of 1-day prior to T0, this object is not significantly detected in gamma rays. A preliminary light curve of the object is available at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/LightCurveRepository/source.php?source_name=4FGL_J2049.9+1002 We encourage multiwavelength observations of this source.
Since Fermi normally operates in an all-sky scanning mode, regular monitoring of this region will continue. For these observations the Fermi-LAT contact person is L. Pfeiffer (leonard.pfeiffer at stud-mail.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 35328
Subject
IceCube-231211A - IceCube observation of a high-energy neutrino candidate track-like event
Date
2023-12-12T16:53:19Z (2 years ago)
From
Giacomo Sommani at Ruhr-Universität Bochum <gsommani@icecube.wisc.edu>
Via
Web form
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
On 2023-12-11 at 00:47:31.79 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 3.30 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/138669_4054005.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:
Date: 2023-12-11
Time: 00:47:31.79 UT
RA: 311.48 (+1.15, -2.33 deg 90% PSF containment) J2000
Dec: +10.28 (+0.67, -0.68 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.
Three gamma-ray sources listed in the 4FGL-DR4 Fermi-LAT catalog are located in the 90% uncertainty of the event. The sources are 4FGL J2044.0+1036, 4FGL J2047.3+1051 and 4FGL J2049.9+1002. The three objects are located 0.6, 0.7 and 1.0 deg away from the best-fit position, respectively. 4FGL J2049.9+1002 was observed in a high-emission state between September and November of this year by Fermi LAT: https://fermi.gsfc.nasa.gov/ssc/data/access/lat/LightCurveRepository/source.html?source_name=4FGL_J2049.9+1002.
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