Swift Observations of GRB 200524A

M. Capalbi (INAF-IASFPA) and P. Kuin (MSSL/UCL) for the Swift team

1. Introduction

Dirirsa et al. (GCN Circ. 27797) reported the GRB detection. Table 1 contains the best reported positions from Swift.

Ho et al. (GCN Circ. 27799) reported the position for the optical afterglow of this GRB. Kuin and Page (GCN Circ. 27825) reported the detection with UVOT of an optical afterglow. Yao et al. (GCN Circ. 29673) determined a redshift of 1.256 from Gemini. Table 2 is a summary of GCN Circulars about this GRB from observatories other than Swift.

2. BAT Observations and Analysis

BAT did not observe this burst.

3. XRT Observations and Analysis

Analysis of the initial XRT data was reported by Capalbi et al. (GCN Circ. 27811).

The light curve (Figure 2) can be modelled with a power-law decay with a decay index of α=3.42 (+0.06, -2.83).

4. UVOT Observations and Analysis

The Swift/UVOT began settled observations (Kuin and Page GCN Circ. 27808) of the field of GRB 200524 36366 s after the LAT trigger (Evans et al., GCN Circ. 27798). The initial Swift UVOT follow up missed the likely afterglow of 200524A as reported by Ho et al. GCN Circ. 27799, and confirmed by Kumar et al. GCN Circ. 27800/27804/27806, Rumyantsev et al. GCN Circ. 27802, Sanwal et al. GCN Circ. 27803, Perley et al., GCN Circ. 27805 and de Ugarte Postigo et al. GCN.Circ. 27807. Table 3 gives preliminary magnitudes using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc., 1358, 373).

Figure 1. The BAT light curve is not available.

RA (J2000) Dec (J2000) Error Note Reference
14h12m10.74s +60°54'19.4" 4.4" XRT Capalbi et al. GCN Circ. 27811

Table 1. Positions from the Swift instruments.

Band Authors GCN Circ. Subject Observatory Notes
Optical Ho et al. 27799 ZTF Discovery of ZTF20abbiixp: The
Likely Optical Afterglow to GRB 200524A		 detection
Optical Kumar et al. 27800 GROWTH-India confirmation of optical
afterglow		 GROWTH-India detection
Optical Lipunov et al. 27801 Fermi GRB 200524A: Global MASTER-Net
observations report 		MASTER
Optical Rumyantsev et al. 27802 CrAO observations of ZTF20abbiixp CrAO detection
Optical Sanwal et al. 27803 3.6m DOT observations of the afterglow
candidate ZTF20abbiixp		 DOT detection
Optical Perley and Ho 27805 Liverpool Telescope observations Liverpool Telescope
Optical Kumar et al. 27806 1.3m DFOT Optical Observation of
ZTF20abbiixp		 DFOT detection
Optical de Ugarte Postigo et al. 27807 CAHA multicolor afterglow detection CAHA detection
Optical Blazek et al. 27810 OAJ multicolor afterglow detection Obs. Astro. de Javalambre detection
Optical Ogawa et al. 27813 MITSuME Akeno optical observation MITSuME Akeno detection
Optical Zheng and Filippenko 27814 KAIT Optical Observations KAIT detection
Optical Izzo 27817 Further Liverpool Telescope observations Liverpool Telescope detection
Optical Belkin et al. 27821 CrAO optical observations CrAO
Optical Hosokawa et al. 27824 optical upper limits from further
MITSuME Akeno observation		 MITSuME Akeno upper limits
Optical Belkin et al. 27830 Assy optical observations Assy-Turgen Obs.
Optical Belkin et al. 27850 Assy continued optical observations Assy-Turgen Obs.
Optical Belkin et al. 27851 SAO RAS optical observations SAO RAS
Optical Yao et al. 29673 Redshift from Gemini-North Gemini redshift
Gamma-ray Dirirsa et al. 27797 Fermi-LAT detection Fermi LAT Emax=9.2 GeV
Gamma-ray Pookalil et al. 27809 Fermi GBM detection Fermi GBM Epeak=192±16 keV
T90=38 seconds
Fluence=2.08±0.03x10-5erg cm-2
(87th percentile for long GRBs)
Gamma-ray Gupta et al. 27818 AstroSat CZTI detection CZTI
Gamma-ray Svinkin et al. 27867 Konus-Wind observation Konus-Wind Epeak=215 (-46,+48) keV
Fluence=3.48(-0.62,+0.74)x10-5erg cm-2
Other Belkin et al. 27820 Kitab observatory afterglow observations marginal detection
Kumar et al. 27804 Correction to the GCN Circ. 27800 corrects Circ. 27800

Table 2. Summary of GCN Circulars from other observatories sorted by band and then circular number.

Table 3. Found no UVOT observations.

March 20, 2021