Swift Observations of GRB 160310A

S.L. Gibson (U. Leicester) and F.E. Marshall (NASA/GSFC) for the Swift team

1. Introduction

Vianello et al. (GCN Circ. 19158) reported the GRB detection. Table 1 contains the best reported positions from Swift.

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

XRT results are not available.

4. UVOT Observations and Analysis

The Swift/UVOT began settled observations (Marshall and Maselli GCN Circ. 19168) of the field of GRB 160310A 40247 s after the LAT trigger (Vianello et al., GCN Circ. 19158). No source is detected in the initial UVOT exposures at a position consistent with the position of the possible XRT afterglow (Gibson et al., GCN Circ. 19162) or the possible optical counterpart (Kruehler et al., GCN Circ. 19164). 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 E_B-V of 0.53 mag. in the direction of the GRB (Schlegel et al. 1998).

Figure 1. The BAT light curve is not available.

RA (J2000) Dec (J2000) Error Note Reference

Table 1. Positions from the Swift instruments.

Band Authors GCN Circ. Subject Observatory Notes

Optical Xu 19163 LCOGT-SAAO optical upper limits Abastumani Astro. Obs. upper limits

Optical Kruehler et al. 19164 NOT optical observations NOT

Optical Troja et al. 19166 RATIR Optical and NIR Observations RATIR

Optical Kruehler et al. 19169 Further NOT observations NOT

Optical Gorbovskoy et al. 19170 MASTER-Kislovods observations MASTER

Optical Sokolov et al. 19210 Terskol 2-m observations Terskol

Gamma-ray Vianello et al. 19158 Fermi-LAT detection Fermi LAT E_max=30 GeV

Gamma-ray Toelge and Hui 19161 Fermi GBM observation Fermi GBM E_peak=129.0±9.5 keV
T₉₀=18.2 seconds
Fluence=4.8±0.2x10^-6erg cm^-2
(56^th percentile for long GRBs)

Gamma-ray Frederiks et al. 19167 Konus-Wind observation of GRB 160310A
(possible ultra-long GRB?) Konus-Wind E_peak=316 (-95,+206) keV

Gamma-ray Svinkin et al. 19209 IPN Triangulation IPN

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

Filter T_start(s) T_stop(s) Exp(s) Mag

u 40247 46726 1273 >20.4

white 41072 41890 805 >21.3

v 41897 42757 843 >19.9

Band	Authors	GCN Circ.	Subject	Observatory	Notes
Optical	Xu	19163	LCOGT-SAAO optical upper limits	Abastumani Astro. Obs.	upper limits
Optical	Kruehler et al.	19164	NOT optical observations	NOT
Optical	Troja et al.	19166	RATIR Optical and NIR Observations	RATIR
Optical	Kruehler et al.	19169	Further NOT observations	NOT
Optical	Gorbovskoy et al.	19170	MASTER-Kislovods observations	MASTER
Optical	Sokolov et al.	19210	Terskol 2-m observations	Terskol
Gamma-ray	Vianello et al.	19158	Fermi-LAT detection	Fermi LAT	E_max=30 GeV
Gamma-ray	Toelge and Hui	19161	Fermi GBM observation	Fermi GBM	E_peak=129.0±9.5 keV T₉₀=18.2 seconds Fluence=4.8±0.2x10^-6erg cm^-2 (56^th percentile for long GRBs)
Gamma-ray	Frederiks et al.	19167	Konus-Wind observation of GRB 160310A (possible ultra-long GRB?)	Konus-Wind	E_peak=316 (-95,+206) keV
Gamma-ray	Svinkin et al.	19209	IPN Triangulation	IPN

Filter	T_start(s)	T_stop(s)	Exp(s)	Mag
u	40247	46726	1273	>20.4
white	41072	41890	805	>21.3
v	41897	42757	843	>19.9

Table 3. UVOT observations reported by Marshall and Maselli (GCN Circ. 19168). 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.

March 22, 2016