2006/08/28 by S. Mereghetti, P. Esposito, A. Tiengo +6 · 5 citations
Physics and Astronomy · #Absorption (acoustics) #Astrophysical Phenomena and Observations #Black-body radiation #Emission spectrum #Equivalent width #Flux (metallurgy) #Gamma-ray bursts and supernovae #Light curve #Line (geometry) #Photon #Pulsars and Gravitational Waves Research #Spectral line #astro-ph
paper · pdf · doi:10.1086/508682
published as Astrophys.J.653:1423-1428,2006 · accepted for publication on The Astrophysical Journal
arxiv created 2006/08/28 · openalex publication_date 2006/12/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A ~50 ks XMM-Newton observation of SGR 1900+14 has been carried out in 2005 September, after almost 3 yr during which no bursts were detected from this soft gamma-ray repeater. The 0.8-10 keV spectrum was well fit by a power law plus blackbody model with photon index Γ = 1.9 ± 0.1, temperature kT = 0.47 ± 0.02 keV, and N H = (2.12 ± 0.08) × 10 22 cm -2 , similar to previous observations of this source. The flux was ~5 × 10 -12 ergs cm -2 s -1 , a factor 2 dimmer than the typical value and the smallest ever seen from SGR 1900+14. The long-term fading of the persistent emission has been interrupted by the recent burst reactivation of the source. A Target of Opportunity XMM-Newton observation performed in 2006 April showed a flux ~15% higher. This variation was not accompanied by significant changes in the spectrum, pulsed fraction, and light-curve profile. We searched for emission and absorption lines in the spectra of the two observations, with negative results and setting tight upper limits of 50-200 eV (3 σ), depending on the assumed line energy and width, on the equivalent width of lines in the 1-9 keV range.