Swift Observations of GRB 160623A

A. Tiengo (IUSS Pavia), B. Mingo (U. Leicester) and A. Breeveld (UCL-MSSL) for the Swift team

1. Introduction

Tiengo et al. (GCN Circ. 19559) reported the initial Swift results. Table 1 contains the best reported positions from Swift.

Pozanenko et al. (GCN Circ. 19561) reported the position from Mondy for the optical afterglow of this GRB. Malesani et al. (GCN Circ. 19708) determined a redshift of 0.367, and Castro-Tirado et al. (GCN Circ. 19710) determined a redshift of 0.367 from GTC. Table 2 is a summary of GCN Circulars about this GRB from observatories other than Swift.

2. BAT Observations and Analysis

BAT refined results are not available.

3. XRT Observations and Analysis

XRT refined results are not available.

4. UVOT Observations and Analysis

The Swift/UVOT began settled observations (Breeveld and Maselli GCN Circ. 19568) of the field of GRB 160623A 40254 s after the LAT trigger (Vianello et al., GCN Circ. 19553). No optical afterglow consistent with the XRT position (Mingo et al. GCN Circ. 19558) or the Mondy and RATIR position (Pozanenko et al. GCN Circ. 19561; Butler et al. GCN Circ. 19567) 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 EB-V of 1.35 mag. in the direction of the GRB (Schlegel et al. 1998).

Figure 1. The BAT light curve is not available.

XRT light curve

Figure 2. The XRT light curve. Any data from a crosshatched region are not included in the fit.

RA (J2000) Dec (J2000) Error Note Reference
21h01m11.54s +42°13'15.4" 1.5" XRT-final UKSSDC
21h01m11.22s +42°13'13.7" 3.5" XRT Mingo et al. GCN Circ. 19558

Table 1. Positions from the Swift instruments.

Band Authors GCN Circ. Subject Observatory Notes
Optical Pozanenko et al. 19561 Mondy optical observations Mondy light curve
Optical Butler et al. 19567 RATIR Optical and NIR Observations,
Afterglow Confirmation		 RATIR detection
Optical Kuroda et al. 19572 MITSuME Ishigakijima Optical Observation MITSuME Ishigakijima detection
Optical Mazaeva et al. 19574 TSHAO optical observations Zeiss-1000 detection
Optical Moskvitin 19614 SAO RAS optical observations SAO RAS
Optical Malesani et al. 19708 optical astrometry, photometry, and
redshift		 RATIR redshift
Optical Castro-Tirado et al. 19710 afterglow spectroscopy by GTC and
independent redshift determination		 GTC spectroscopy
Radio Urata et al. 19584 SMA submm afterglow observations SMA
Radio Mooley et al. 19609 Possible detection of a radio afterglow
at 15 GHz with AMI		 AMI possible detection
Radio Nayana et al. 19848 Possible radio detection of GRB160623A
with the GMRT		 GMRT possible detection
Gamma-ray Vianello et al. 19553 Galactic transient: Fermi-LAT detection Fermi LAT
Gamma-ray Frederiks et al. 19554 Konus-Wind observation Konus-Wind Epeak=562 (-23,+23) keV
Fluence=6.6(-0.1,+0.1)x10-4erg cm-2
Gamma-ray Mailyan et al. 19555 Fermi GBM detection/observation Fermi GBM Fluence=5.598±0.369x10-6erg cm-2
Gamma-ray Yamaoka et al. 19597 CALET Gamma-Ray Burst Monitor detection CALET

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

Filter Tstart(s) Tstop(s) Exp(s) Mag
v 40657 51652 2859 >21.1
u 40254 51253 2008 >21.5

Table 3. UVOT observations reported by Breeveld and Maselli (GCN Circ. 19568). The start and stop times of the exposures are given in seconds since the BAT trigger. The preliminary 3-σ upper limits are given. No correction has been made for extinction in the Milky Way.

August 24, 2016