IceCube-200615A
GCN Circular 27979
Subject
Swift/UVOT Observations of IceCube 200615A
Date
2020-06-18T12:15:15Z (5 years ago)
From
Frank Marshall at Swift/UVOT <marshall@milkyway.gsfc.nasa.gov>
F.E. Marshall (GSFC), P.A. Evans (U. Leicester), T. Gregoire (PSU), J.A. Kennea (PSU),
H. A. Ayala Solares (PSU), D.F. Cowen (PSU), J. DeLaunay (PSU) , D. B. Fox (PSU),
A. Keivani (Columbia U.), F. Krauss (PSU), and J.P. Osborne (U. Leicester) report:
Swift observed the field of IceCube 200615A (GCN Circ. 27950) between 08:58:51 UT
2020 June 15 and 11:12:28 UT on 2020 June 16. The observations used
7 pointing directions to tile the inner part of the 90% confidence
region for the neutrino event. The results of the XRT observations
were reported by Evans et al. (GCN Circ. 27973).
UVOT observed the 7 tiling directions using the U filter
covering a total of ~0.57 deg**2. The UVOT field-of-view is co-aligned
with the XRT's but is smaller than the XRT's.
We analyzed the longest exposure for each direction,
which ranged from 337 s to 363 s. The averge exposure was 348 s.
No uncatalogued point sources were found with a
typical sensitivity limit of 19.0 mag.
We also searched for counterparts to the XRT sources reported by
Evans et al. (GCN Circ. 27973).
Sources 1, 3, 4, and 6 were detected with UVOT and are
also in the Digital Sky Survey.
Source 2 was not detected with UVOT.
Source 9 is near a bright galaxy, which was detected with UVOT.
Sources 5, 7, and 8 are outside the field-of-view of UVOT
for all the observations.
GCN Circular 27973
Subject
Swift-XRT observations of IceCube 200615A
Date
2020-06-17T07:53:24Z (5 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester), T. Gregoire (PSU), J.A. Kennea (PSU),
H. A. Ayala Solares (PSU), D.F. Cowen (PSU), J. DeLaunay (PSU) , D. B. Fox (PSU),
A. Keivani (Columbia U.), F. Krauss (PSU), F.E. Marshell (GSFC)
J.P. Osborne (U. Leicester) report:
Swift observed the field of IceCube 200615A (GCN Circ. 27950) between 08:58:51 UT
2020 June 15 and 11:12:28 UT on 2020 June 16, collecting a total of 12.8 ks of
cleaned photon counting (PC) mode data. The observations used a 7-point tiling
pattern with a radius of ~0.5 degrees.
We found 9 X-ray sources, as detailed below. All of these are either known X-ray
sources consistent with catalogued fluxes, or are unknown but with count rates
consistent with the previous non-detections. We therefore do not claim any of
them as the likely counterpart to IceCube 200615A
The 3-sigma upper limit in the field was in the range 3.6-6.4 x 10^-3 ct/sec.
The detected sources were:
Source 1:
RA (J2000): `09h 31m 17.80s` = 142.82418 deg
Dec (J2000): `+03d 31' 18.4"` = 3.52179 deg
Err(radius): 2.5"
Count rate (0.3-10 keV): 0.040 ( +/- 0.004)
Flux (0.3-10 keV): 1.72 (+/- 0.19) x 10^-12
Notes: This source corresponds to 1RXS J093117.6+033146.
Source 2:
RA (J2000): `09h 31m 00.25s` = 142.75103 deg
Dec (J2000): `+03d 30' 02.6"` = 3.50071 deg
Err(radius): 6.9"
Count rate (0.3-10 keV): 2.3 (+1.7, -1.1) x 10^-3
Flux (0.3-10 keV): 10 (+7, -5) x 10^-14
Notes: This does not match a catalogued X-ray source, but the RASS
3-sigma upper limit at this position corresponds to 0.028 ct/sec
in XRT.
WARNING: This was a low significance detection which may well be spurious.
Source 3:
RA (J2000): `09h 30m 32.99s` = 142.63746 deg
Dec (J2000): `+03d 44' 43.2"` = 3.74534 deg
Err(radius): 4.0"
Count rate (0.3-10 keV): 0.020 ( +/- 0.004)
Flux (0.3-10 keV): 8.5 (+1.8, -1.6) x 10^-13
Notes: This does not match a catalogued X-ray source, but the RASS
3-sigma upper limit at this position corresponds to 0.031 ct/sec
in XRT.
The position is consistent with 2MASX J09303302+0344432
Source 4:
RA (J2000): `09h 33m 04.66s` = 143.26942 deg
Dec (J2000): `+03d 56' 42.4"` = 3.94512 deg
Err(radius): 5.6"
Count rate (0.3-10 keV): 8.7 (+3.1, -2.5) x 10^-3
Flux (0.3-10 keV): 3.8 (+1.3, -1.1) x 10^-13
Notes: This source corresponds to 1RXS J093305.7+035648.
Source 5:
RA (J2000): `09h 30m 36.31s` = 142.65130 deg
Dec (J2000): `+03d 31' 25.3"` = 3.52369 deg
Err(radius): 5.0"
Count rate (0.3-10 keV): 3.4 (+1.6, -1.2) x 10^-3
Flux (0.3-10 keV): 1.5 (+0.7, -0.5) x 10^-13
Notes: This does not match a catalogued X-ray source, but the RASS
3-sigma upper limit at this position corresponds to 0.021 ct/sec
in XRT.
WARNING: This was a low significance detection which may well be spurious.
Source 6:
RA (J2000): `09h 32m 01.68s` = 143.00700 deg
Dec (J2000): `+03d 18' 57.7"` = 3.31602 deg
Err(radius): 5.8"
Count rate (0.3-10 keV): 7.8 (+2.8, -2.3) x 10^-3
Flux (0.3-10 keV): 3.34 (+1.22, -0.98) x 10^-13
Notes: This does not match a catalogued X-ray source, but the RASS
3-sigma upper limit at this position corresponds to 0.12 ct/sec
in XRT.
The position is consistent with QSO J0932+0318
Source 7:
RA (J2000): `09h 30m 57.98s` = 142.74159 deg
Dec (J2000): `+03d 31' 51.0"` = 3.53083 deg
Err(radius): 4.4"
Count rate (0.3-10 keV): 1.95 (+1.20, -0.86) x 10^-3
Flux (0.3-10 keV): 8 (+5, -4) x 10^-14
Notes: This does not match a catalogued X-ray source, but the RASS
3-sigma upper limit at this position corresponds to 0.027 ct/sec
in XRT.
WARNING: This was a low significance detection which may well be spurious.
Source 8:
RA (J2000): `09h 32m 53.51s` = 143.22296 deg
Dec (J2000): `+04d 05' 00.4"` = 4.08343 deg
Err(radius): 5.2"
Count rate (0.3-10 keV): 5.4 (+2.6, -1.9) x 10^-3
Flux (0.3-10 keV): 2.31 (+1.10, -0.84) x 10^-13
Notes: This does not match a catalogued X-ray source, but the RASS
3-sigma upper limit at this position corresponds to 0.035 ct/sec
in XRT.
Source 9:
RA (J2000): `09h 30m 58.40s` = 142.74333 deg
Dec (J2000): `+03d 48' 33.3"` = 3.80925 deg
Err(radius): 4.9"
Count rate (0.3-10 keV): 2.3 (+2.1, -1.3) x 10^-3
Flux (0.3-10 keV): 10 (+9, -6) x 10^-14
Notes: This does not match a catalogued X-ray source, but the RASS
3-sigma upper limit at this position corresponds to 0.017 ct/sec
in XRT.
The position is consistent with SDSS-C4-DR3 1119
WARNING: This was a low significance detection which may well be spurious.
All errors are at the 90% confidence level, fluxes are observed flux in erg cm^-2 s^-1
and are calculated assuming an absorbed power-law with NH=3e20 and Gamma=1.7
GCN Circular 27972
Subject
IceCube-200615A: No significant detection in HAWC
Date
2020-06-17T03:29:03Z (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 2020/06/15 14:49:17 UTC, the IceCube collaboration reported a
track-like very-high-energy event that has a high probability of
being an astrophysical neutrino, IceCube-200615A. Location is at
RA: 142.95 (+1.18/-1.45 deg 90% PSF containment) J2000
Dec: 3.66 (+1.19/-1.06 deg 90% PSF containment) J2000
(GCN circular 27950).
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 7.89e-4 (2.35e-2 post-trials),
is at RA 141.46 deg, Dec 2.91 deg (��0.15 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 = 3.08e-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 2020/06/14 01:10:07 UTC and ended
2020/06/16 01:16:55 UTC.
The most significant location, with p-value 1.19e-2 (3.03e-1 post-trials),
is at RA 141.68 deg, Dec 3.10 deg (��0.22 deg 68% containment) J2000.
We set a time-integrated 95% CL upper limit at the position of
maximum significance of:
E^2 dN/dE = 7.04e-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.
GCN Circular 27970
Subject
Fermi-LAT Gamma-ray Observations of IceCube-200615A
Date
2020-06-16T21:20:18Z (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
IC200615A neutrino event (GCN 27950) 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 2020-06-15 at 14:49:17.38
UT (T0) with J2000 position RA =142.95 (+1.18 -1.45) deg, Decl. = 3.66
(+1.19 -1.06) deg 90% PSF containment. No cataloged >100 MeV gamma-ray
sources (The Fermi-LAT Collaboration 2019, arXiv:1902.10045)�are located
within the 90% IC200615A 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
IC200615A 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 < 3e-10 ph cm^-2 s^-1 for
~11-years (2008-08-04 / 2020-06-15 UTC), < 3e-9 (< 3e-8) 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 27968
Subject
IceCube-200615A: Upper limits from a search for additional neutrino events in IceCube
Date
2020-06-16T16:08:39Z (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-200615A (https://gcn.gsfc.nasa.gov/gcn3/27950.gcn3) in a time
range of 2 days centered on the alert event time (2020-06-14 14:49:17.380 UTC to 2020-06-16 14:49:17.380 UTC) during which IceCube was collecting good quality data. Excluding the
event that prompted the alert, zero additional track-like events are found in spatial coincidence
with the 90% containment region of IceCube-200615A. We accordingly derive a time-integrated muon-neutrino flux upper limit at the alert position of E^2 dN/ dE = 3.3 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 5 PeV.
A subsequent search was performed to include the month of data prior to the alert event (2020-05-16 14:49:17.380 UTC to 2020-06-16 14:49:17.380 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
5.9 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 27957
Subject
IceCube-200615A: Upper limits from Fermi-GBM Observations
Date
2020-06-15T20:31:57Z (5 years ago)
From
Joshua Wood at MSFC/Fermi-GBM <joshua.r.wood@nasa.gov>
J. Wood (NASA/MSFC) reports on behalf of the Fermi-GBM team:
For the IceCube high-energy neutrino candidate event IceCube-200615A
(GCN 27950), at the event time Fermi-GBM was observing the reported
neutrino location at:
RA: 142.95 (+1.18 -1.45 deg 90% PSF containment) J2000
Dec: 3.66 (+1.19 -1.06 deg 90% PSF containment) J2000
There was no Fermi-GBM onboard trigger around the event time of the
neutrino candidate. An automated, blind search for short gamma-ray
bursts below the onboard triggering threshold in Fermi-GBM also
identified no counterpart candidates. The GBM targeted search,
the most sensitive, coherent search for GRB-like signals,
was run from +/-30 s around the neutrino candidate time.
From this search, no significant signal was found related
to IceCube-200615A.
We set upper limits on impulsive gamma-ray emission. Using the
representative soft, normal, and hard GRB-like templates described in
arXiv:1612.02395, we set the following 3 sigma flux upper limits over
10-1000 keV (in units of 10^-7 erg/s/cm^2):
Timescale Soft Normal Hard
-------------------------------------------
0.128 s: 7.5 11. 26.
1.024 s: 1.8 2.9 6.4
8.192 s: 0.4 0.9 2.2
These results are preliminary.
GCN Circular 27954
Subject
IceCube-200615A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
Date
2020-06-15T17:51:12Z (5 years ago)
From
Maeve Doyle at U College Dublin, Ireland <maeve.doyle.1@ucdconnect.ie>
M. Doyle, A. Martin-Carrillo (UCD, Ireland)
V. Savchenko, C. Ferrigno (ISDC/UniGE, Switzerland)
J. Rodi (IAPS-Roma, Italy)
A. Coleiro (APC, France)
S. Mereghetti (INAF IASF-Milano, Italy)
on behalf of the INTEGRAL multi-messenger collaboration:
https://www.astro.unige.ch/cdci/integral-multimessenger-collaboration
Using INTEGRAL/SPI-ACS realtime data (following [1]) we have performed
a search for a prompt gamma-ray counterpart of IceCube-200615A (GCN 27950).
At the time of the event (2020-06-15 14:49:17 UTC, hereafter T0),
INTEGRAL was operating in nominal mode. The peak of the event
localization probability was at an angle of 132 deg with respect to
the spacecraft pointing axis. This orientation implies strongly
suppressed (3.4% of optimal) response of ISGRI, somewhat suppressed
(43% of optimal) response of IBIS/Veto, and somewhat suppressed (50%
of optimal) response of SPI-ACS.
The background within +/-300 seconds around the event was very stable
(excess variance 1.1).
We have performed a search for any impulsive events in INTEGRAL SPI-
ACS (as described in [2]) data.
We do not detect any significant counterparts and estimate a 3-sigma
upper limit on the 75-2000 keV fluence of 3.5e-07 erg/cm^2 (within the
50% probability containment region of the source localization) for a
burst lasting less than 1 s with a characteristic short GRB spectrum
(an exponentially cut off power law with alpha=-0.5 and Ep=600 keV)
occurring at any time in the interval within 300 s around T0. For a
typical long GRB spectrum (Band function with alpha=-1, beta=-2.5, and
Ep=300 keV), the derived peak flux upper limit is ~3.2e-07 (9.4e-08)
erg/cm^2/s at 1 s (8 s) time scale in 75-2000 keV energy range.
We report for completeness and in order of FAP, all excesses
identified in the search region. We find 4 likely background
excesses:
T-T0 | scale | S/N | flux ( x 1e-06 erg/cm2/s) | FAP
-4.06 | 0.3 | 3.3 | 0.709 +/- 0.223 +/- 0.271 | 0.143
-13.8 | 0.35 | 3.6 | 0.711 +/- 0.207 +/- 0.272 | 0.226
67.8 | 4.6 | 3.1 | 1.67 +/- 0.566 +/- 0.641 | 0.301
18.1 | 0.2 | 3.7 | 0.974 +/- 0.274 +/- 0.372 | 0.409
Note that FAP estimates (especially at timescales above 2s) may be
possibly further affected by enhanced non-stationary local background
noise. This list excludes any excesses for which FAP is close to
unity.
All results quoted are preliminary.
This circular is an official product of the INTEGRAL Multi-Messenger
team.
[1] Savchenko et al. 2017, A&A 603, A46
[2] Savchenko et al. 2012, A&A 541A, 122S
GCN Circular 27950
Subject
IceCube-200615A: IceCube observation of a high-energy neutrino candidate event
Date
2020-06-15T16:11:39Z (5 years ago)
From
Cristina Lagunas Gualda at DESY <cristina.lagunas@desy.de>
The IceCube Collaboration (http://icecube.wisc.edu/) reports:
On 20/06/15 at 14:49:17.38 UT IceCube detected a track-like event with a high probability of being of astrophysical origin. The event was selected by the ICECUBE_Astrotrack_Gold alert stream. The average astrophysical neutrino purity for Gold alerts is 50%. This alert has an estimated false alarm rate of 0.29 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/134191_17593623.amon), more sophisticated reconstruction algorithms have been applied offline, with the direction refined to:
Date: 20/06/15
Time: 14:49:17.38 UT
RA: 142.95 (+1.18 -1.45 deg 90% PSF containment) J2000
Dec: 3.66 (+1.19 -1.06 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-LAT 4FGL or 3FHL sources inside the 90% localization region. The closest source is 4FGL J0922.6+0434 located at RA 140.67 deg and Dec 4.58 deg (J2000), at a distance of 2.46 degrees from the best-fit location.
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