ZTF22aaajecp
GCN Circular 31846
Subject
ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, SAO RAS, CrAO)
Date
2022-04-07T15:18:20Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), A. Pozanenko (IKI), E. Klunko (ISTP), A. Moskvitin
(SAO RAS), O. A. Maslennikova (SAO RAS), V. Rumyantsev (CrAO), S. Belkin
(IKI, HSE) report on behalf of GRB IKI FuN:
We continue to observe the optical transient ZTF22aaajecp/AT2022cmc
(Andreoni et al., GCN 31590) with AZT-33 telescope of Mondy
observatory, Zeiss-1000 telescope of SAO RAS, ZTSh telescope of CrAO. We
detect the transient (Andreoni et al., GCN 31590; Kumar et al., GCN
31597; Pankov et al., GCNs 31593, 31625, 31652, 31798; Perley, GCN
31594; Lipunov et al., GCN 31600; Kann et al., GCN 31626; Yao et al.,
GCN 31641; Freeburn et al., GCN 31647; Smith et al., GCN 31654; Dobie et
al., GCN 31665; Sfaradi et al., GCN 31667; Cenko et al., GCN 31729;
Dimple et al., GCN 31805) at the redshift of z=1.193
(Tanvir et al., GCN 31602; Lundquist et al., GCN 31612).
Preliminary photometry of the transient observed in Mondy observatory on
April, 5 and 6, 2022 is following
Date UT start MJD Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2022-04-05 17:40:24 59674.7572 R 30*120 21.08 0.09 22.8
2022-04-06 20:13:03 59675.8563 R 20*120 21.35 0.11 22.8
The photometry is based on the nearby SDSS-DR12 stars
R.A. Dec R(Lupton transformations)
203.7398307 33.1702037 17.794
203.7684775 33.1572431 17.347
The light curve of ZTF22aaajecp/AT2022cmc can be found at
http://grb.rssi.ru/AT2022cmc/AT_2022cmc_LC_MJD.png
GCN Circular 31805
Subject
ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
Date
2022-03-29T19:04:43Z (4 years ago)
From
Rahul Gupta at ARIES, India <rahulbhu.c157@gmail.com>
Dimple, Rahul Gupta, Ankur Ghosh, Naveen Dukiya, Amit Kumar, Amit Ror, Amar
Aryan, Kiran Wani, Kuntal Misra, and S. B. Pandey (ARIES) report:
We observed the fast and red optical transient ZTF22aaajecp/AT2022cmc
discovered with the Zwicky Transient Facility (Andreoni et al., GCN 31590)
using 1.3m Devasthal Fast Optical Telescope (DFOT) located at Devasthal
observatory of Aryabhatta Research Institute of Observational Sciences
(ARIES), India. The observations were carried out at multiple epochs. Here,
we report our last night's observations, which started on 22-03 28
at 19:32:05 UT~ 45.4 days after the first detection by the ZTF. We have
taken multiple frames having an exposure time of 120 sec in the R filter.
We stacked the images after the alignment. We detected ZTF22aaajecp/AT2022cmc
(Andreoni et al., GCN 31590; Pankov et al., GCNs 31593, 31625, 31652, 31798;
Perley, GCN 31594; Kumar et al., GCN 31597; Lipunov et al., GCN 31600; Tanvir
et al., GCN 31602; Lundquist et al., GCN 31612; Kann et al., GCN 31626; Yao
et al., GCN 31641; Freeburn et al., GCN 31647; and Cenko et al., GCN 31729) in
our stacked image. The estimated preliminary magnitude is following:
Date Start_UT T_start-T0 (days) Filter Exp time (sec) magnitude
==============================================================
2022-03-28 19:32 ~45.4 R 120 sec*60 22.04 +/-
0.10
The magnitude is not corrected for the Galactic extinction in the direction
of the burst. Photometric calibration is performed using the standard stars
from the USNO-B1.0 catalog.
This circular may be cited.
GCN Circular 31798
Subject
ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
Date
2022-03-27T15:25:15Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), A. Pozanenko (IKI), E. Klunko (ISTP), I. Reva (FAI),
R. Ya. Inasaridze (AbAO), S. Belkin (IKI, HSE) report on behalf of GRB
IKI FuN:
We continued observations optical transient of ZTF22aaajecp/AT2022cmc
(Andreoni et al., GCN 31590) with AZT-33 telescope of Mondy
observatory, Zeiss-1000 telescope of Tien Shan Astronomical Observatory,
AS-32 telescope of Abastumani observatory. We detect the transient
(Andreoni et al., GCN 31590; Kumar et al., GCN 31597; Pankov et al.,
GCNs 31593, 31625, 31652; Perley, GCN 31594; Lipunov et al., GCN 31600;
Kann et al., GCN 31626; Yao et al., GCN 31641; Freeburn et al., GCN
31647; Smith et al., GCN 31654; Dobie et al., GCN 31665; Sfaradi et
al., GCN 31667; Cenko et al., GCN 31729) at the redshift of z=1.193
(Tanvir et al., GCN 31602; Lundquist et al., GCN 31612).
Preliminary photometry of the transient observed in Mondy observatory on
March, 26, 2022 is following
Date UT start MJD Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2022-03-26 17:10:49 59664.728 R 17*120 21.61 0.13 23.0
The photometry is based on the nearby SDSS-DR12 stars
R.A. Dec R(Lupton transformations)
203.7398307 33.1702037 17.794
203.7684775 33.1572431 17.347
The light curve of ZTF22aaajecp/AT2022cmc can be found at
http://grb.rssi.ru/AT2022cmc/AT_2022cmc_LC_MJD.png
GCN Circular 31729
Subject
ZTF22aaajecp/AT2022cmc: Hubble Space Telescope Observations
Date
2022-03-10T03:34:06Z (4 years ago)
From
Brad Cenko at NASA/GSFC <brad.cenko@nasa.gov>
S. B. Cenko (NASA/GSFC), I. Andreoni (JSI/UMD/GSFC), and M. Coughlin (UMN) report on behalf of a larger collaboration:
The location of the transient source AT2022cmc (Andreoni et al., GCN 31590) was observed with the Hubble Space Telescope beginning at 2022 Mar 8 20:12:21 UT (~ 25.4 d after discovery). The field was imaged with the Wide-Field Camera 3 (WFC3) in the F606W (UVIS) and F160W (IR) filters for 1044 s and 1059 s, respectively.
AT2022cmc is well detected in both bands. Using preliminary calibrations, we estimate AB magnitudes of F606W = 21.88 +/- 0.05 mag and F160W = 22.24 +/- 0.06 mag at this time. The source appears unresolved, without obvious evidence for extended emission directly underneath.
A second HST epoch to constrain the presence of an underlying host galaxy is planned for July/August 2022.
We thank the HST operations team for the approval and rapid execution of these observations.
GCN Circular 31667
Subject
ZTF22aaajecp/AT2022cmc: AMI-LA radio detection
Date
2022-03-03T15:28:11Z (4 years ago)
From
Itai Sfaradi at Hebrew U of Jerusalem <itai.sfaradi@mail.huji.ac.il>
Itai Sfaradi (HUJI), Lauren Rhodes (Oxford), David Williams
(JBCA/Manchester), Joe Bright (Berkeley), Assaf Horesh (HUJI), Rob Fender
(Oxford), Dave Green (Cambridge), David Titterington (Cambridge)
We report the detection of radio emission from the fast and red optical
transient AT2022cmc (ZTF22aaajecp; Andreoni et al. 2020, GCN 31590).
We observed the field of AT 2022cmc with the Arcminute Microkelvin Imager ���
Large Array (AMI-LA) for 4 hours on the 2022-02-26, with a central
frequency of 15.5 GHz. A point source is detected in the AMI-LA image at RA
= 13:34:43.28 Dec = +33:13:02.43, consistent with the reported position of
AT2022cmc. The source is detected at a flux density of ~0.5 mJy.
We plan to perform follow-up observations with the AMI-LA, and encourage
further high cadence multi frequency radio observations with other
facilities.
We thank the staff of MRAO for scheduling and performing this observation.
GCN Circular 31665
Subject
ZTF22aaajecp/AT2022cmc: ATCA detection
Date
2022-03-02T22:55:50Z (4 years ago)
From
Dougal Dobie at VAST <ddobie94@gmail.com>
D. Dobie (Swinburne/OzGrav), A. O'Brien (UW Milwaukee),
A. Zic (Macquarie U./CSIRO), D.L. Kaplan (UW Milwaukee),
D.A. Perley (LJMU), A.Y.Q Ho (UC Berkeley)
We carried out observations of ZTF22aaajecp/AT2022cmc
(Andreoni et al. GCN 31590) with the Australia Telescope Compact
Array (ATCA) on 2022-02-26 (~15.25 days post-discovery).
The array was in the EW367 array configuration and we excluded CA06
from our processing to obtain more uniform u-v coverage. We used
3C286 for gain, bandpass and flux scale calibration to ensure
consistency with observations from Northern radio facilities.
We detect a compact radio source at the location of the transient
and measure a flux density of ~1.6 mJy at 33.5 GHz.
Further observations are planned.
Thank you to CSIRO staff for supporting these observations.
GCN Circular 31654
Subject
ZTF22aaajecp/AT2022cmc: JCMT SCUBA-2 sub-mm observations
Date
2022-02-27T01:28:55Z (4 years ago)
From
Ian Smith at Rice U <ian.smith.astronomy@gmail.com>
I.A. Smith (U. Hawaii), D.A. Perley (LJMU), and N.R. Tanvir
(U. of Leicester) report:
We have been observing the VLA location of the transient
ZTF22aaajecp/AT2022cmc (Andreoni et al. GCN Circ. 31590; Perley
et al. GCN Circ. 31592) using the SCUBA-2 sub-millimeter continuum
camera on the James Clerk Maxwell Telescope. The source was
detected with a 850 micron flux density of 4.9 mJy/beam at a
mid-point of UT 2022-02-21.510.
We thank Jasmin Silva, Alexis-Ann Acohido, Harold Pena, and the
JCMT staff for the prompt support of these observations that were
taken under project M22AP030.
GCN Circular 31652
Subject
ZTF22aaajecp/AT2022cmc: Mondy optical observations
Date
2022-02-25T23:06:07Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI),
report on behalf of GRB IKI FuN:
We observed the optical transient of ZTF22aaajecp/AT2022cmc (Andreoni
et al., GCN 31590) with AZT-33 telescope of Mondy observatory starting
on Feb. 24 (UT) 18:51:38. We detect the transient (Andreoni et al., GCN
31590; Kumar et al., GCN 31597; Pankov et al., GCNs 31593, 31625;
Perley, GCN 31594; Lipunov et al., GCN 31600; Kann et al., GCN 31626;
Yao et al., GCN 3164; Freeburn et al., GCN 31647) at the redshift of
z=1.193 (Tanvir et al., GCN 31602; Lundquist et al., GCN 31612).
Preliminary photometry of the transient is following
Date UT start MJD Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2022-02-24 18:51:38 59634.817 R 45*120 21.10 0.07 23.1
The photometry is based on the nearby SDSS-DR12 stars
R.A. Dec R(Lupton transformations)
203.7398307 33.1702037 17.794
203.7684775 33.1572431 17.347
GCN Circular 31647
Subject
ZTF22aaajecp/AT2022cmc: DECam Photometry
Date
2022-02-25T09:00:22Z (4 years ago)
From
Jielai Zhang at Swinburne U. of Tech. <jielaizhangscience@gmail.com>
ZTF22aaajecp/AT2022cmc: DECam Photometry
James Freeburn (Swinburne, OzGrav), Jielai Zhang (Swinburne, OzGrav), Igor
Andreoni (University of Maryland, NASA GFSC), Armin Rest (STScI, Johns
Hopkins), Dougal Dobie, Anais M��ller, Simon Goode, Jeff Cooke (Swinburne,
OzGrav), Katie Auchettl (University of Melbourne, OzGrav), Frank Valdes
(NOAO), Charlie Kilpatrick (Northwestern University), David Jones (UCSC),
Tim Abbott (NOAO), Bruce Gendre (University of Western Australia, OzGrav),
Amy Lien (University of Tampa), Lee Spitler (Macquarie University)
As part of the Kilonova and Transients Program (KNTraP, NOIRLab Proposal ID
2022A-679480, PI: Zhang) observing run, we conducted follow-up observations
of ZTF22aaajecp/AT2022cmc (I. Andreoni et al. GCNC #31590) with the Dark
Energy Camera (DECam) on the CTIO 4m Victor Blanco Telescope between
February 15 and 22,
approximately 3-10 days after the initial ZTF detection. We took nightly
observations each with a combination of g, r, i and z
band exposures. We present preliminary photometry (calibrated with the
Pan-STARRS photometric catalogs using Gaia star selection) from these
exposures.
We would also like to acknowledge the CTIO staff, especially Kathy Vivas,
Jacqueline Seron, Alberto Alvarez and Claudio Aguilera, who kept our
observations running smoothly.
filter,UTC,MJD,magnitude,error
g,2022-02-15 08:43:36.768,59625.36362,20.567,0.21
g,2022-02-16 08:59:18.958,59626.37452,>20.88,n/a
g,2022-02-17 08:51:49.783,59627.36933,>20.80,n/a
g,2022-02-18 08:52:29.856,59628.36979,21.296,0.24
r,2022-02-15 08:44:36.384,59625.36431,20.587,0.13
r,2022-02-16 09:00:19.432,59626.37522,21.024,0.34
r,2022-02-17 08:53:48.480,59627.37070,21.522,0.33
i,2022-02-15 08:45:35.136,59625.36499,20.133,0.20
i,2022-02-16 09:01:18.624,59626.37591,21.243,0.28
i,2022-02-17 08:54:47.892,59627.37139,21.364,0.38
i,2022-02-18 08:55:27.840,59628.37185,21.212,0.22
i,2022-02-19 09:03:22.618,59629.37735,21.277,0.19
i,2022-02-20 09:03:44.446,59630.37760,21.630,0.23
i,2022-02-21 08:51:57.024,59631.36941,21.648,0.25
i,2022-02-22 08:51:46.489,59632.36929,21.625,0.27
z,2022-02-16 09:02:18.240,59626.37660,21.094,0.22
z,2022-02-17 08:55:46.848,59627.37207,21.234,0.28
z,2022-02-18 08:58:06.816,59628.37369,21.292,0.23
z,2022-02-19 09:06:22.930,59629.37943,21.354,0.21
z,2022-02-20 09:07:01.470,59630.37988,21.263,0.26
z,2022-02-21 08:55:14.880,59631.37170,21.812,0.36
z,2022-02-22 08:55:05.176,59632.37157,22.183,0.45
GCN Circular 31641
Subject
ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
Date
2022-02-23T19:00:52Z (4 years ago)
From
Yuhan Yao at Caltech <yyao@astro.caltech.edu>
Yuhan Yao (Caltech), Igor Andreoni (JSI), Sergio Campana (INAF-OAB), Brad Cenko (GSFC)
AT2022cmc was discovered by the Zwicky Transient Facility (ZTF) on 2022 Feb 11 as a fast and red optical transient (GCN 31590). At z=1.193 (GCN 31602, 31612), its luminous radio, millimeter, and X-ray emission (GCN 31592, 31627, 31601) distinguish AT2022cmc from most extragalactic transients. The highly variable X-ray emission, the hardness evolution, and the power-law energy break revealed by NICER+NuSTAR observations make it similar to the relativistic TDE Swift J1644+57 (ATel 15230, 15232).
On Feb 23, the Neil Gehrels Swift Observatory conducted a 2.6-ks observation at rest-frame 5.3 days after the first ZTF detection (i.e., 2022-02-11T10:42:40).
AT2022cmc was detected by the X-Ray Telescope (XRT) at a count rate of 0.197+/- 0.0091 count/s. The Swift/XRT image shows just one source coincident with the radio position (GCN 31592), within the errors.
We grouped the XRT spectrum to have at least 20 counts per bin and fitted the 0.3�6 keV spectrum with tbabs*ztbabs*zashift*powerlaw. We fixed the column density nH in tbabs at the Galactic value of 8.88 E+19 cm^-2 (HI4PI Collaboration et al. 2016). We obtained a good fit with a chi-square/degrees of freedom (chi2/dof) of 20.54/15. The best-fit power law index Gamma = 1.41 +0.26 -0.22, and host galaxy nH = 0.21 +0.43 -0.21 E+22 cm^-2 (errors are 90% confidence level for one parameter of interest). We note that the host nH is consistent with 0. The observed 0.3�6 keV flux is 5.4 +/- 0.6 E-12 erg/s/cm^2, which is similar to the NICER 0.3�6 keV flux of 8.7 +/- 0.1 E-12 erg/s/cm^2 on Feb 19 (Atel 15232).
Photometry with the UltraViolet/Optical Telescope (UVOT) gives the following magnitudes (5� extraction region)
Filter exptime (s) AB mag
V 83.44 > 18.70
B 83.44 > 19.63
U 83.44 > 20.44
UVW2 419.06 > 22.09
UVM2 634.64 21.30 +/- 0.22 (stat) +/- 0.03 (sys)
UVW1 251.73 > 21.35
Upper limits are reported in 3-sigma.
The detection in the M2 band testifies for a low intrinsic absorbing column density.
GCN Circular 31625
Subject
ZTF22aaajecp/AT2022cmc: Terskol observatory optical observations
Date
2022-02-21T20:28:05Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Pankov (HSE), I. Sokolov (INASAN, KIAM), V. Kozlov (IC AMER), Y.
Markelov (KIAM), I. Izvekova (Institute of physics of NAS, IC AMER
NASU), Y. Markus (Institute of physics of NAS, IC AMER NASU), G.
Butenko (Institute of physics of NAS), A. Pozanenko (IKI), S. Belkin
(IKI, HSE) report on behalf of GRB IKI FuN:
We observed the optical transient of ZTF22aaajecp/AT2022cmc (Andreoni
et al., GCN 31590) with K-800 telescope, and Zeiss-600 telescope of
Terskol observatory on Feb. 15 and Feb. 17. We detected the optical
transient (Andreoni et al., GCN 31590; G��N-bibliography in Tanvir et
al., GCN 31602; see also Lipunov et al., GCN 31600) at the redshift of
z=1.193 (Tanvir et al., GCN 31602; Lundquist et al., GCN 31612) in
first epoch observation with K-800 in Clear filter. Preliminary
photometry of the transient and upper limit is following
Date UT start t-T0 Filter Exp. OT Err UL(3sigma) Telescope
2022-02-15 23:15:36 4.939271 C 93*30 20.15 0.2 20.9 K-800
2022-02-17 00:38:05 5.994641 C 88*30 n/d n/d 20.4 K-800
The photometry is based on the nearby SDSS-DR12 stars R (Lupton
transformations)
R.A. Dec R
203.7398307 33.1702037 17.794
203.7684775 33.1572431 17.347
GCN Circular 31612
Subject
ZTF22aaajecp/AT2022cmc: Keck DEIMOS Redshift
Date
2022-02-19T19:46:02Z (4 years ago)
From
Michael J. Lundquist at Keck <mlundquist@keck.hawaii.edu>
Michael J Lundquist, Carlos A. Alvarez, and John O'Meara (W. M. Keck Observatory)
We observed the fast, red optical transient ZTF22aaajecp/AT2022cmc (Andreoni et al., GCN 31590) using the DEIMOS spectrograph at the W. M. Keck Observatory.
We obtained spectroscopy covering the wavelength range 5250-8780 AA, consisting of 3 exposures of 900s each starting at 2022-02-17 15:07 UT. Data was reduced using the PypeIt data reduction pipeline (Prochaska, J. Xavier et al., 2020).
The spectrum had low S/N, but the transient is detected over the full wavelength range. We confirm the detection and interpretation of the absorption lines at 6132, 6148 AA as the Mg II 2796, 2803 AA lines and the absorption lines at 5671, 5702 AA as the Fe II 2586, 2600 AA lines as reported by Tanvir et al. (GCN 31602), agreeing with the reported redshift of 1.193. The Ca II 3934 line is detected at 8629 AA, however we do not clearly identify the Ca II 3969 line at 8706 AA.
The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.
GCN Circular 31605
Subject
ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory continued optical observations
Date
2022-02-18T19:54:06Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE), A. Pozanenko (IKI), I. Nikolenko (IANSAN), S. Belkin
(IKI) report on behalf of GRB IKI FuN:
We observed the optical transient of ZTF22aaajecp/AT2022cmc (Andreoni
et al., GCN 31590) with Zeiss-1000 telescope of Koshka observatory
starting on Feb. 16 (UT) 20:52:267 in R- and I -filters. We do not
detect the optical transient (Andreoni et al., GCN 31590;
G��N-bibliography in Tanvir et al., GCN 31602; see also Lipunov et al.,
GCN 31600) at the redshift of z=1.193 (Tanvir et al., GCN 31602).
Preliminary photometry of the field is following
Date UT start MJD Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2022-02-16 20:52:26 59626.89683 R 78*60 n/d n/d 21.3
2022-02-16 20:54:47 59626.90575 I 99*60 n/d n/d 21.3
The photometry is based on the nearby SDSS-DR12 stars R(Lupton
transformations)
R.A. Dec R I
203.7398307 33.1702037 17.794 17.450
203.7684775 33.1572431 17.347 16.911
GCN Circular 31602
Subject
ZTF22aaajecp/AT2022cmc: VLT/X-shooter redshift
Date
2022-02-17T16:33:02Z (4 years ago)
From
Valerio D'Elia at ASDC <valerio.delia@ssdc.asi.it>
N. R. Tanvir (Univ. Leicester), A. de Ugarte Postigo (Obs. Cote D���Azur), L. Izzo (DARK/NBI), S. D. Vergani (GEPI, Observatoire de Paris), V. D���Elia (ASI/SSDC, INAF/OAR), S. Campana (INAF-OAB), D. A. Perley (LJMU), K. Wiersema (Univ. Lancaster), A.J. Levan (Radboud), D. A. Kann (HETH/IAA-CSIC), A. Rossi (INAF-OAS), M. Della Valle (INAF-OAC) report on behalf of the Stargate Consortium:
We observed the fast and red optical transient ZTF22aaajecp/AT2022cmc (GCN Circ. 31590), also detected by VLA (GCN Circ. 31592), Zeiss-1000 (GCN Circ. 31593), LT (GCN Circ. 31594), GMOS-N (GCN Circ. 31595), GIT (GCN Circ. 31597), and NICER (GCN Circ. 31601), using the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph.
A spectrum was secured covering the wavelength range 3000-21000 AA, and consisting of 4 exposures of 1200 s each. The observation was carried out about six days after the transient discovery.
In a preliminary reduction, the continuum is detected over the full spectral range. An emission line is detected at 10981 AA, which we interpret as due to OIII 5007 at a redshift of 1.193. The corresponding OIII 4959 line falls on a telluric feature, so it is not detected in our spectrum. Moreover, the Halpha emission line is in a telluric gap. However, a set of absorption lines from Mg (MgII 2796, MgII 2803 and MgI 2803), FeII (2344, 2383, 2586, 2600), and CaII (3934, 3969) are present at a consistent redshift. Thus we interpret it as the redshift of the transient. We note that the NICER X-ray detection (GCN Circ. 31601) is very bright if at this redshift.
We acknowledge excellent support from the ESO observing staff in Paranal, in particular Claudia Paladini and Ditte Slumstrup.
GCN Circular 31601
Subject
ZTF22aaajecp/AT2022cmc: NICER X-ray detection
Date
2022-02-17T04:19:47Z (4 years ago)
From
Dheeraj R. Pasham at Mass. Inst. of Technology <dheeraj@space.mit.edu>
Dheeraj Pasham (MIT), Keith Gendreau (NASA/GSFC), Zaven Arzoumanian
(NASA/GSFC), Brad Cenko (NASA/GSFC)
NICER observed the rapidly fading red transient AT2022cmc for 640 seconds
starting at 2022-02-16T19:07:03. X-rays are clearly detected above the
background in the 0.3-6.0 keV band with a mean count rate of 12.9+-0.14
counts/seconds. We fit the 0.3-6 keV X-ray spectrum with a powerlaw
modified by neutral absorption (tbabs*pow in XSPEC). This gives a good fit
with a chi-squared/degrees of freedom of 216/207. The best-fit power law
index and column density values are 1.56+-0.05 and (3.9+-0.7)e21 cm^-2,
respectively. The 0.3-6 keV observed flux is (3.04+-0.05)e-11 erg/s/cm^2.
Further NICER observations are planned. To coordinate NICER/X-ray
observations with other facilities please contact drrreddy@mit.edu.
NICER can carry out prompt follow-up observations of transients and is
planning to systematically follow up alerts from LIGO/Virgo and other X-ray
bright extra-galactic transients in the future.
NICER is a 0.2-12 keV X-ray telescope operating on the International Space
Station. The NICER mission and portions of the NICER science team
activities are funded by NASA.
--
Dheeraj Pasham
Research Scientist, MIT
http://space.mit.edu/~dheeraj
GCN Circular 31597
Subject
ZTF22aaajecp: GIT optical follow-up observations
Date
2022-02-16T09:21:16Z (4 years ago)
From
Harsh Kumar at Indian Inst of Tech,Bombay <harshkosli13@gmail.com>
H. Kumar(IITB), J. Stanzin (IAO), V. Bhalerao(IITB), G. C. Anupama(IIA), S.
Barway(IIA) report on behalf of the GROWTH-India team:
We observed ZTF22aaajecp/AT2022cmc discovered by Zwicky Transient Facility
(Andreoni et al., (GCN 31590) and further followed-up by D. A. Perley et
al., (GCN 31592), N. Pankov et al., (GCN 31593) D. A. Perley et al., (GCN
31594) and T. Ahumada et al., (GCN 31595); with the 0.7m GROWTH-India
Telescope (GIT). We obtained multiple 300-sec exposures in the r' and
i��� filters.
The source is clearly detected in the stacked images. The photometric
results follow as:
-------------------------------------------------------------------
JD (mid) | Filter | Exposure | Magnitude (AB) |
-------------------------------------------------------------------
2459626.37303 | r��� | 300 x 6 | 20.46 +/- 0.09 |
2459626.28331 | i��� | 300 x 5 | 20.08 +/- 0.08 |
-------------------------------------------------------------------
The photometric results are in agreement with the decay reported by N.
Pankov et al., (GCN 31593) and D. A. Perley et al., (GCN 31594). The
magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and
not corrected for Galactic extinction.
The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7-degree
field of view, set up by the Indian Institute of Astrophysics (IIA) and the
Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and
IUSSTF. It is located at the Indian Astronomical Observatory (Hanle),
operated by IIA. We acknowledge funding by the IITB alumni batch of 1994,
which partially supports operations of the telescope. Telescope technical
details are available at https://sites.google.com/view/growthindia/.
GCN Circular 31595
Subject
ZTF22aaajecp/AT2022cmc: GMOS-N spectroscopy
Date
2022-02-16T00:55:47Z (4 years ago)
From
Tomas Ahumada at U. of Maryland <tahumada@astro.umd.edu>
T. Ahumada (UMD), C. Fremling (Caltech), A.Y.Q. Ho (UCB), M. M. Kasliwal
(Caltech), D. Perley (LJMU), I. Andreoni (JSI) , S. Anand (Caltech) report
on behalf of the ZTF collaboration
We obtained spectroscopy of ZTF22aaajecp/AT2022cmc (Andreoni et al., GCN
31590, Perley et al., GCN 31592, Pankov et al. GCN 31593) with the Gemini
Multi-Object Spectrographs (GMOS-N) mounted on the Gemini-North 8-meter
telescope on Mauna Kea, under our ToO program GN-2022A-Q-127 (PI: Ho). We
obtained 2x450 second exposures using the B600 grating and 2x450 second
exposures using the R400 grating, starting 2022-02-15 14:35 UTC.
After two independent reductions using DRAGONS (Labrie et al. 2019) and
Pyraf we report a featureless red continuum. The lack of any narrow or
broad lines in our spectral coverage (380nm to 910nm, although the S/N is
low blueward of 550 nm) is consistent with a cosmological origin (and
suggests an AGN-like or a Galactic origin is unlikely).
We thank the observers and the Gemini staff for their rapid response in
facilitating this Target of Opportunity observation.
--
Tomas Ahumada (he/him)
Ph.D. Candidate
Department of Astronomy
University of Maryland, College Park
NASA Goddard Space Flight Center, Code 661
B.Sc. Astronomy, Pontificia Universidad Cat��lica de Chile
GCN Circular 31594
Subject
ZTF22aaajecp/AT2022cmc: Liverpool Telescope photometry
Date
2022-02-15T23:25:52Z (4 years ago)
From
Daniel Perley at Liverpool JMU <d.a.perley@ljmu.ac.uk>
D. A. Perley (LJMU) reports:
We acquired multicolor imaging of the fast optical transient ZTF22aaajecp (AT2022cmc; Andreoni et al. 2020, GCN 31590) using the IO:O camera of the 2m robotic Liverpool Telescope. The afterglow was observed across four separate epochs in g, r, i, and z filters during the night ending 2022-02-15 UT, with the first epoch beginning at 00:50 and the last at 05:54. The images show a clear detection of the transient in all bands. Photometry with reference to SDSS secondary standard stars in the field gives the following magnitudes during the final epoch:
MJD dt(d) filter mag unc
59625.2461 3.8003 g 20.72 0.16
59625.2501 3.8042 r 20.17 0.09
59625.2540 3.8082 i 20.16 0.07
59625.2580 3.8121 z 19.91 0.11
The dt column above is the time in days after the first detection as reported by Andreoni et al. (2022-02-11 10:42 UT).
The SED is consistent with a power-law with an index of beta=-1 (f_nu ~ nu^beta), similar to GRB afterglows. This provides additional evidence in support of the interpretation of this event as a relativistic cosmological explosion (see also Perley et al., GCN 31592). Spectroscopic confirmation is still required.
DisclaimerNone
GCN Circular 31593
Subject
ZTF22aaajecp/AT2022cmc: Zeiss-1000 of Koshka observatory optical observations
Date
2022-02-15T22:23:37Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE) A. Pozanenko (IKI), A. Novichonok (Petrozavodsk State
University, KIAM), A. Zhornichenko (KIAM), S. Belkin (IKI), report
on behalf of GRB IKI FuN:
We observed the optical transient of ZTF22aaajecp/AT2022cmc (Andreoni
et al., GCN 31590) with Zeiss-1000 telescope of Koshka observatory
starting on Feb. 14 (UT) 21:09:47. We clearly detect the transient
(Andreoni et al., GCN 31590) which is also detected in radio (Perley et
al., GCN 31592).
Preliminary photometry of the transient is following
Date UT start MJD Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2022-02-14 21:09:47 59621.07347 R 60*76 20.39 0.15 21.5
The photometry is based on the nearby SDSS-DR12 stars
R.A. Dec R(Lupton transformations)
203.7398307 33.1702037 17.794
203.7684775 33.1572431 17.347
GCN Circular 31592
Subject
ZTF22aaajecp/AT2022cmc: VLA radio detection
Date
2022-02-15T21:00:08Z (4 years ago)
From
Daniel Perley at Liverpool JMU <d.a.perley@ljmu.ac.uk>
D. A. Perley (LJMU) reports on behalf of a larger collaboration:
We acquired observations of the fast optical transient ZTF22aaajecp (AT2022cmc; Andreoni et al. 2020, GCN 31590) with the Karl G. Jansky Very Large Array (VLA) between 12:06 and 12:49 UT on 2022 February 15. Observations were carried out using the X-band receivers at a mean frequency of 10 GHz. We detect a radio source at a location (J2000) of:
RA = 13:34:43.203
Dec = 33:13:00.670
with an uncertainty of 0.01" in each coordinate. The position is consistent with the location of the optical transient. The flux density of the source is approximately 57 microJy at this time.
The presence of a radio counterpart at this flux level is typical of GRB afterglows within a few days of explosion, and supports the hypothesis that this event is a cosmological relativistic transient. Additional observations are planned.
We thank the VLA staff for rapidly scheduling and executing these observations.
DisclaimerNone
GCN Circular 31590
Subject
ZTF22aaajecp/AT2022cmc: Zwicky Transient Facility discovery of a fast and red optical transient
Date
2022-02-14T18:47:06Z (4 years ago)
From
Igor Andreoni at JSI <igor.andreoni@gmail.com>
Igor Andreoni (JSI), Michael Coughlin (UMN), Tomas Ahumada (UMD), Mansi
Kasliwal (Caltech), Daniel Perley (LJMU), Eric Burns (LSU), Mattia Bulla
(OKC), Brad Cenko (NASA/GSFC), Shreya Anand (Caltech), Erik Kool (OKC)
We report the discovery of the fast and red optical transient
ZTF22aaajecp/AT2022cmc with the Zwicky Transient Facility (ZTF, Bellm et
al. 2019, Graham et al. 2019) at coordinates:
RA = 13:34:43.20 (203.6800149d)
Dec = +33:13:00.44 (33.2167887d)
ZTF22aaajecp was first detected on 2022-02-11 10:42 UT at r=20.73 +- 0.3
mag. The last ZTF upper limit before the first detection was measured on
2022-01-21 09:54 UT. ZTF22aaajecp increased its luminosity to r=19.04 +-
0.16 mag in 23.2 hours, then it faded by 0.8 mag in the following 48 hours.
The latest detection of ZTF22aaajecp occurred on 2022-02-14 09:40 UT,
r=19.84 +- 0.19 mag.
The color of ZTF22aaajecp appears to be red, with g-r~0.25 mag and g-i~0.5
mag at the observed peak on 2022-02-12. The Galactic extinction on the line
of sight is small, with E(B-V)=0.01 mag (Planck Collaboration et al.,
2014). The source is located at a high Galactic latitude of b=78.85 deg.
ZTF22aaajecp does not have any cataloged underlying source in deep Legacy
Survey DR9 images. The fast evolution and red color suggest that
ZTF22aaajecp could be a gamma-ray burst afterglow, but a spectroscopic
confirmation is required to determine the nature of the transient.
ZTF22aaajecp is spatially and temporally consistent with the Fermi-GBM
short GRB 220211A (GBM trigger 666234473); however, it is located several
degrees outside the IPN localization region for this event (Ridnaia et al.
2022; GCN 31584).
Follow-up observations are strongly encouraged.
ZTF22aaajecp was discovered by the ''ZTF Realtime Search and Triggering''
project (ZTFReST; Andreoni & Coughlin et al., 2021) within the ZTF
Collaboration.
Based on observations obtained with the Samuel Oschin Telescope 48-inch and
the 60-inch Telescope at the Palomar Observatory as part of the Zwicky
Transient Facility project. ZTF is supported by the National Science
Foundation under Grant No. AST-2034437 and a collaboration including
Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center
at Stockholm University, the University of Maryland, Deutsches
Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of
Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin,
Lawrence Livermore National Laboratories, and IN2P3, France. Operations are
conducted by COO, IPAC, and UW.