Swift Observations of GRB 140330A

A. D'Ai (INAF-IASFPA) for the Swift team

1. Introduction

Vianello et al. (GCN Circ. 16048) reported the GRB detection. At 04:19:54.47 UT on March 30, 2014, Fermi-LAT detected high-energy emission from GRB 140330A, which was also detected by Fermi-GBM (trigger 417845997). Table 1 contains the best reported positions from Swift, and the latest XRT position can be viewed at http://www.swift.ac.uk/xrt_positions.

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 D'Ai et al. (GCN Circ. 29372).

We have analysed 3.2 ks of XRT data for the Fermi/LAT-detected burst GRB 140330A, from 102.0 ks to 120.0 ks after the Fermi/LAT trigger. The data are entirely in Photon Counting (PC) mode. The source has a mean count rate of 2.4 x 10^-2 ct s^-1; we cannot determine at the present time whether it is fading.

A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.8 (+0.7, -0.5). The best-fitting absorption column is 9 (+17, -5) x 10²⁰ cm^-2, consistent with the Galactic value of 3.5 x 10²⁰ cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.4 x 10^-11 (4.1 x 10^-11) erg cm^-2 count^-1.

A summary of the PC-mode spectrum is thus:
Total column: 9 (+17, -5) x 10²⁰ cm^-2
Galactic foreground: 3.5 x 10²⁰ cm^-2
Excess significance: <1.6 σ
Photon index: 1.8 (+0.7, -0.5)

The results of the XRT team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020372.

4. UVOT Observations and Analysis

UVOT results are not available.

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

21^h41^m46.19^s -64°11'17.4" 4.0" XRT-refined D'Ai et al. GCN Circ. 29372

Table 1. Positions from the Swift instruments.

Band Authors GCN Circ. Subject Observatory Notes

Gamma-ray Vianello et al. 16048 Fermi-LAT Detection Fermi LAT E_max=4.5 GeV

Gamma-ray Golenetskii et al. 16056 Konus-Wind observation Konus-Wind E_peak=158 (-24,+34) keV
Fluence=3.9(-0.5,+0.6)x10^-6erg cm^-2

Gamma-ray Pittori et al. 16058 intense and persistent gamma-ray
emission detected by AGILE AGILE

Gamma-ray Vianello et al. 16062 Retraction of the Fermi/LAT
high-energy counterpart for GRB 140330A Fermi LAT

Gamma-ray Pelassa et al. 16066 Fermi GBM observation Fermi GBM E_peak=197±17 keV
T₉₀=34 seconds
Fluence=5.6±0.3x10^-6erg cm^-2
(59^th percentile for long GRBs)

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

RA (J2000)	Dec (J2000)	Error	Note	Reference
21^h41^m46.19^s	-64°11'17.4"	4.0"	XRT-refined	D'Ai et al. GCN Circ. 29372

Band	Authors	GCN Circ.	Subject	Observatory	Notes
Gamma-ray	Vianello et al.	16048	Fermi-LAT Detection	Fermi LAT	E_max=4.5 GeV
Gamma-ray	Golenetskii et al.	16056	Konus-Wind observation	Konus-Wind	E_peak=158 (-24,+34) keV Fluence=3.9(-0.5,+0.6)x10^-6erg cm^-2
Gamma-ray	Pittori et al.	16058	intense and persistent gamma-ray emission detected by AGILE	AGILE
Gamma-ray	Vianello et al.	16062	Retraction of the Fermi/LAT high-energy counterpart for GRB 140330A	Fermi LAT
Gamma-ray	Pelassa et al.	16066	Fermi GBM observation	Fermi GBM	E_peak=197±17 keV T₉₀=34 seconds Fluence=5.6±0.3x10^-6erg cm^-2 (59^th percentile for long GRBs)

January 30, 2021