Search for polarization from the prompt gamma-ray emission of GRB 041219a with SPI on INTEGRAL

Kalemci, Emrah and Boggs, Steven E. and Kouveliotou, Chryssa and Finger, Mark H. and Baring, Matthew (2007) Search for polarization from the prompt gamma-ray emission of GRB 041219a with SPI on INTEGRAL. Astrophysical Journal Supplement Series, 169 (1). pp. 75-82. ISSN 0067-0049 (Print) 1538-4365 (Online)

[thumbnail of ek_polarization.pdf] PDF

Download (548kB)


Measuring the polarization of the prompt γ-ray emission from gamma-ray bursts (GRBs) can significantly improve our understanding of both the GRB emission mechanisms as well as the underlying engine driving the explosion. We searched for polarization in the prompt γ-ray emission of GRB 041219a with the SPI instrument on INTEGRAL. Using multiple-detector coincidence events in the 100-350 keV energy band, our analysis yields a polarization fraction from this GRB of 98%+/-33%. Statistically, we cannot claim a polarization detection from this source. Moreover, different event selection criteria lead to even less significant polarization fractions, e.g., lower polarization fractions are obtained when higher energies are included in the analysis. We cannot strongly rule out the possibility that the measured modulation is dominated by instrumental systematics. Therefore, SPI observations of GRB 041219a do not significantly constrain GRB models. However, this measurement demonstrates the capability of SPI to measure polarization, as well as the techniques developed for this analysis.
Item Type: Article
Uncontrolled Keywords: gamma rays : bursts; gamma rays : observations; instrumentation : polarimeters methods :; data analysis; polarization; techniques : polarimetric
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Faculty of Engineering and Natural Sciences
Depositing User: Emrah Kalemci
Date Deposited: 25 Oct 2007 12:25
Last Modified: 26 Apr 2022 08:16

Actions (login required)

View Item
View Item