GRB 240414A
GCN Circular 37576
Subject
GRB 240414A: further radio observations with the VLA
Date
2024-09-20T14:43:52Z (a year ago)
From
Stefano Giarratana at INAF-OAB <s.giarratana@ira.inaf.it>
Via
email
S. Giarratana (INAF-OAB), M. Giroletti (INAF-IRA),
G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.),
N. Omodei (Stanford Univ.), O. S. Salafia (INAF-OAB)
At 01:21:27 UT on 2024 April 23 (T_mid = 8.98 days post-burst)
and at 05:22:12 on 2024 May 15 (T_mid = 31.15 days post-burst)
the Karl G. Jansky VLA started observing the field of GRB 240414A
(Caputo et al., GCN 36083) at a central frequency of 6 and 10 GHz.
The standard J1331+3030 (3C286) was used as bandpass and flux density
calibrator, while J1217+5835 was used as complex gain calibrator.
From a preliminary analysis, the radio source coincident with
GRB 240414A (Rhodes et al., GCN 36229; Giarratana et al., GCN 36231;
de Ugarte Postigo et al., GCN 36318) is detected at both frequencies:
================================================================
T_mid Freq Peak r.m.s. Beam PA
[days] [GHz] [uJy/b] [uJy/b] [arcsec] [deg]
================================================================
8.98 6 33 9 4.64x3.44 -86
8.98 10 48 7 3.16x2.24 -82
31.15 6 18 6 1.15x0.92 -40
31.15 10 21 6 0.67x0.56 -38
================================================================
We would like to thank the staff of the VLA for approving, executing,
and processing the observations.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc.
These observations were carried out as part of project SF161095,
approved in the framework of the Fermi - NRAO joint program agreement.
GCN Circular 36318
Subject
GRB 240414A: NOEMA detection
Date
2024-04-26T15:39:53Z (2 years ago)
From
Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>
Via
email
A. de Ugarte Postigo (CNRS/OCA & LAM), M. Bremer (IRAM), C. C. Thoene (ASU-CAS), J. F. Agui Fernandez (CAHA), S. Antier (OCA), S. Basa (LAM), M. Michalowski (AOI-AMU), D. A. Perley (LJMU), J.-G. Ducoin (CPPM) report:
We observed the field of GRB 240414A (Caputo et al. GCN 36083; Myers et al. GCN 36120; Cheung et al. GCN 36147) with the NOEMA interferometer, located at the Plateau de Bure (France). The observation, performed on the 23rd April, was tuned with sidebands at 74 and 90 GHz.
When combining all the data, we obtain a weak, 3-sigma detection at the position of the afterglow (Schneider et al. GCN 36084; Adami et al. GCN 36085; de Ugarte Postigo GCN 36087; Dutton et al. 36097; Turpin et al. GCN 36101; Osborne et al. GCN 36102; Dichiara et al. GCN 36104; Pankov et al. GCN 36113; Siegel et al. GCN 36115; de Ugarte Postigo et al. GCN 36117; Wang et al. GCN 36131; Rossi et al. GCN 36228; Rhodes et al. GCN 36229; Giarratana et al. GCN 36231) with a flux density of ~55 uJy.
Based on observations carried out under project number W23DI with the IRAM NOEMA Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).
GCN Circular 36231
Subject
GRB 240414A: radio detection with the VLA
Date
2024-04-22T16:59:02Z (2 years ago)
From
Stefano Giarratana at University of Bologna <s.giarratana@ira.inaf.it>
Via
email
S. Giarratana (INAF-OAB), M. Giroletti (INAF-IRA),
G. Ghirlanda (INAF-OAB), N. Di Lalla (Stanford Univ.),
N. Omodei (Stanford Univ.)
At 01:42:45 UT on 2024 April 17 (T_mid = 2.99 days post-burst) the
Karl G. Jansky VLA started observing the field of GRB 240414A
(Caputo et al., GCN 36083) at a central frequency of 6 and 10 GHz.
The standard J1331+3030 (3C286) was used as bandpass and flux density
calibrator, while J1217+5835 was used as complex gain calibrator.
From a preliminary analysis, an unresolved radio source is clearly
detected at both frequencies at a position:
RA: 12:19:08.08 +- 0.01
Dec: +56:44:28.7 +- 0.2
The surface brightness peak is 40 uJy/beam and 60 uJy/beam at 6
and 10 GHz, respectively. The r.m.s. noise level of the images is
7 uJy/beam at both 6 and 10 GHz.
The synthesized beams are 4.1 x 3.0 arcsec (PA: 70deg) at 6 GHz
and 2.7 x 1.9 arcsec (PA: 76deg) at 10 GHz.
While no source is detected at the aforementioned position in previous
radio surveys (FIRST, NVSS, VLASS), their r.m.s. noise levels (1sigma)
is above 100 uJy/b, well above the derived surface brightness peak.
Therefore, we cannot exclude the contribution from the GRB host galaxy yet.
We would like to thank the staff of the VLA for approving, executing,
and processing the observations.
The National Radio Astronomy Observatory is a facility of the National
Science Foundation operated under cooperative agreement by Associated
Universities, Inc.
These observations were carried out as part of project SF161095,
approved in the framework of the Fermi - NRAO joint program agreement.
GCN Circular 36229
Subject
GRB 240414A: AMI-LA radio observations
Date
2024-04-22T15:06:17Z (2 years ago)
From
Lauren Rhodes at Oxford <lauren.rhodes@physics.ox.ac.uk>
Via
Web form
Lauren Rhodes, Rob Fender (Oxford), Dave Green, Dave Titterington (Cambridge) report:
We observed the field of the afterglow candidate GRB 240414A (GCN #36083) with the Arcminute Microkelvin Imager Large-Array (AMI-LA) at 15.5 GHz beginning at 18:54UT on 20-Apr-2024 for a total of 4 hours. The flux standard 3c286 was used to calibrate the bandpass response and flux scale of the AMI-LA and J1219+4829 was used as an interleaved complex gain calibrator.
We do not detect any radio emission at the position of the afterglow candidate as reported in GCN #36102 at a 3 sigma upper limit of 297uJy/beam.
We thank the staff at the Mullard Radio Astronomy Observatory for carrying out these observations and operating the AMI-LA.
GCN Circular 36228
Subject
GRB 240414A: LBT optical detection
Date
2024-04-22T14:43:25Z (2 years ago)
From
Andrea Rossi at INAF <andrea.rossi@inaf.it>
Via
Web form
A. Rossi, E. Maiorano, E. Palazzi (INAF-OAS), M . De Pasquale (Univ. of Messina), report on behalf of the CIBO collaboration:
We observed the field of GRB 240414A (Caputo et al. GCN 36083) simultaneously in the blue and red arms with the g'-, r'-, and z'-bands with the MODS instrument mounted on LBT (Mt Graham, AZ, USA). Observations were obtained at the midtime 05:41 UT on 2024-04-14, 3 hours and 20 minutes after the burst trigger.
We detect the optical transient (Schneider et al., GCN 36084, Aryan et al., GCN 36094, Dutton et al., GCN 36097, Xu et al., GCN 36105, Pankov et al., GCN 36113, Wang et al., GCN 36131) in all bands and we measure a preliminary AB magnitudes r'=19.1+-0.1, calibrated against SDSS field stars, and not corrected for the foreground Galactic extinction.
We acknowledge the excellent support from the LBTO and LBT-INAF staff, particularly A. Cardwell, J. Williams, F. Cusano and D. Paris, in obtaining these observations.
GCN Circular 36147
Subject
GRB 240414A: Glowbug gamma-ray detection
Date
2024-04-17T14:54:25Z (2 years ago)
From
C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>
Via
Web form
C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240414A, which was also detected by Swift/BAT (GCN 36083