D.N. Burrows (PSU) and A.A. Breeveld (UCL-MSSL) for the Swift team
Dalessi (GCN Circ. 33407) reported the GRB detection. At 15:44:06.67 UT on 07 March 2023, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 230307A (trigger 699896651 / 230307656). Table 1 contains the best reported positions from Swift.
Levan et al. (GCN Circ. 33439) reported the position for the optical afterglow of this GRB. Breeveld and Salvaggio (GCN Circ. 33471) reported the detection with UVOT of an optical afterglow. Levan et al. (GCN Circ. 33580) determined a redshift of 3.87 from JWST. Table 2 is a summary of GCN Circulars about this GRB from observatories other than Swift.
BAT did not observe this burst.
Analysis of the initial XRT data was reported by Burrows et al. (GCN Circ. 33465). Of the sources reported by Burrows et al. (GCN Circ. 33429), "Source 2" is fading with >3-sigma significance, and is therefore likely the GRB afterglow.
The light curve (Figure 2) can be modelled with a power-law decay with a decay index of α=1.1 (+0.6, -0.5).
The Swift/UVOT began observations
(Breeveld and Salvaggio GCN Circ. 33471) of the field of GRB 230307A 99.5 ks after the Fermi/GBM-detected trigger (Dalessi et al., GCN Circ. 33407).
A fading source consistent with the enhanced XRT position (Burrows et al., GCN Circ. 33465) and consistent with the optical counterpart reported by Levan et al. (GCN Circ. 33439), Lipunov et al. (GCN Circ. 33441), Fulton et al. (GCN Circ. 33443), O'Connor et al. (GCN Circ. 33447), Im et al. (GCN Circ. 33449), Vanderspek et al. (GCN Circ. 33453) and Bom et al. (GCN Circ. 33459) is detected in the initial UVOT exposures.
Table 3 gives preliminary
magnitudes using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc., 1358, 373).
No correction has been made for the expected extinction in the Milky Way
corresponding to a reddening of
Figure 1. The BAT light curve is not available.
RA (J2000) | Dec (J2000) | Error | Note | Reference |
---|---|---|---|---|
0 |
-75°22'43.8" | 3.2" | XRT | Burrows et al. GCN Circ. 33465 |
Band | Authors | GCN Circ. | Subject | Observatory | Notes |
---|---|---|---|---|---|
Optical | Lipunov et al. | 33428 | Fermi GRB 230307A: Global MASTER-Net observations report |
MASTER | |
Optical | Pérez-GarcÃa et al. | 33434 | optical upper limit | BOOTES | upper limits |
Optical | Levan et al. | 33439 | Possible optical afterglow | ||
Optical | Fulton et al. | 33443 | ATLAS information on the ULTRACAM optical afterglow candidate |
ATLAS | detection |
Optical | O'Connor et al. | 33447 | Gemini-South Confirmation of the Optical Afterglow |
Gemini | detection |
Optical | Im et al. | 33449 | GECKO optical observations and detections of the afterglow |
SSO | detection |
Optical | Vanderspek et al. | 33453 | TESS Detection of the Optical Afterglow | detection | |
Optical | Bom et al. | 33459 | SOAR/Goodman detection of the possible host galaxy |
Southern Astro.Research Telescope | |
Optical | Gillanders et al. | 33485 | Continued Gemini-South observations confirm rapid optical fading |
Gemini | |
Optical | Levan et al. | 33569 | JWST observations consistent with the presence of a kilonova |
JWST | |
Optical | Levan et al. | 33580 | JWST NIRSpec observations, possible higher redshift |
JWST | redshift |
Optical | 33635 | iTelescope optical upper limit (likely) | iTelescope | upper limits | |
Radio | Anderson et al. | 33475 | ATCA radio detection | ATCA | detection |
X-ray | Xiao | 33410 | Solar Orbiter STIX observation | Spectr.Tele. for Imag.X-rays | light curve |
X-ray | Katoch et al. | 33437 | AstroSat LAXPC detection | LAXPC | detection |
X-ray | Sugita et al. | 33448 | MAXI/GSC upper limit | MAXI | upper limits |
X-ray | Liu et al. | 33466 | soft X-ray detection with LEIA | Lobster Eye Imager | detection |
X-ray | Grefenstette | 33478 | Far off-axis NuSTAR detection of the GRB | NuSTAR | detection |
X-ray | Escorial et al. | 33558 | Chandra late-time detection of the X-ray afterglow |
Chandra | detection |
Gamma-ray | Fermi | 33405 | Fermi GBM Final Real-time Localization | Fermi GBM | |
Gamma-ray | Xiong et al. | 33406 | GECAM detection of an extremely bright burst |
GECAM | |
Gamma-ray | Dalessi | 33407 | Fermi GBM detection of a very bright GRB | Fermi GBM | |
Gamma-ray | Dalessi et al. | 33411 | Fermi GBM Observation of a very bright burst |
Fermi GBM | Fluence=2.951±0.004x1 (brighter than 100.0% of long GRBs) |
Gamma-ray | Casentini et al. | 33412 | AGILE/MCAL detection | AGILE | |
Gamma-ray | Kozyrev et al. | 33413 | IPN triangulation of GRB 230307A (long/very bright) |
IPN | |
Gamma-ray | Navaneeth et al. | 33415 | AstroSat CZTI detection | CZTI | |
Gamma-ray | Biltzinger et al. | 33416 | BALROG localization (Fermi Trigger 699896651/ GRB 230307656) |
BALROG | |
Gamma-ray | Dafcikova et al. | 33418 | Detection by GRBAlpha | GRBAlpha | |
Gamma-ray | Ripa et al. | 33424 | VZLUSAT-2 detection | VZLUSAT | |
Gamma-ray | Kozyrev et al. | 33425 | Improved IPN localization for GRB 230307A |
IPN | |
Gamma-ray | Svinkin et al. | 33427 | Konus-Wind detection | Konus-Wind | Duration=~196 seconds Fluence=3.58(-0.08,+0.08)x1 |
Gamma-ray | Li | 33438 | ASO-S/HXI detection | Hard X-ray Imager | |
Gamma-ray | Casentini et al. | 33444 | AGILE/MCAL analysis | AGILE | |
Gamma-ray | Kozyrev et al. | 33461 | Further improved IPN localization for GRB 230307A |
IPN | |
Gamma-ray | V. Savchenko | 33472 | INTEGRAL upper limit on Hard X-ray afterglow |
INTEGRAL | |
Gamma-ray | Dalessi | 33551 | Bad Time Intervals for Fermi GBM data | Fermi GBM | |
Gamma-ray | Svinkin et al. | 33579 | further analysis of the Konus-Wind detection and rest-frame energetics |
Konus-Wind | |
Neutrino | Collaboration | 33430 | Upper limits from a neutrino search with IceCube |
IceCube | upper limits |
Other | Burns et al. | 33414 | possibly the second highest GRB energy fluence ever identified |
||
Other | Lipunov | 33442 | Erratum of the GCN Circ. 33441 | ||
Other | Camisasca et al. | 33577 | short mininum variability timescale compatible with a merger origin |
light curve | |
Other | Bulla et al. | 33578 | good match with kilonova models |
Filter | Exp(s) | Mag | ||
---|---|---|---|---|
white | 99525 | 110441 | 2265 | 21.28 ± 0.16 |
white | 133031 | 208070 | 2931 | 22.09 ± 0.32 |
white | 212899 | 420530 | 3418 | >22.25 |
u | 83621 | 88252 | 422 | >20.44 |
Table 3. UVOT observations reported by Breeveld and Salvaggio (GCN Circ. 33471). The start and stop times of the exposures are given in seconds since the BAT trigger. The preliminary detections and 3-σ upper limits are given. No correction has been made for extinction in the Milky Way.
May 9, 2023