anomalous X-ray pulsar @ about 30 Light Years has been very active as of late

1 kpc = 3.26156 ly

the distance of 1E1547.0-5408 is 10 kpc , distance inferred for the dust layer responsible for the scattering is about 7 kpc

Over a period of January 21 23:49:41 - January 22 23:47:00 (UT), the WAM detected about 250 bursts

AXP 1E1547.0-5408 that recently reactivated (GCN 8833, 8835, 8837, 8838


1E1547.0-5408: Swift detection of dust halo
Tiengo et al.
GCN 8848
SOURCE: GCN
TITLE: GCN CIRCULAR
NUMBER: 8848
SUBJECT: 1E1547.0-5408: Swift detection of dust halo
DATE: 09/01/24 00:52:59 GMT
FROM: Sandro Mereghetti at IASF/CNR <[email protected]>

A. Tiengo, S. Mereghetti, G. Vianello, P. Esposito (INAF-IASF Milano), G. L. Israel (INAF-OAR), N. Rea (Amsterdam Univ.), and D. Gotz (CeA Saclay), on behalf of a larger collaboration report:
Swift/XRT observation performed on January 23 from 15:23 to 15:51 UT in Photon Counting mode shows the presence of a dust scattering halo around the position of the Anomalous X-ray Pulsar 1E1547.0-5408. A bright ring with a radius of about 1 arcmin is clearly visible, but the observation is too short to detect expansion. Assuming that this ring is due to the bright burst detected on Jan 22 at 06:48:04 UT (Mereghetti et al. GCN 8841), and that the distance of 1E1547.0-5408 is 10 kpc, the distance inferred for the dust layer responsible for the scattering is about 7 kpc. Further observations to measure the time evolution of the dust scattering rings can provide tighter constraints.


he Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV detected the current burst activities most likely arising from the AXP 1E1547.0-5408, as reported by Swift BAT (Gronwall et al., GCN 8833), INTEGRAL SPI-ACS (Savchenko et al., GCN 8837) and Fermi GBM (Connaughton et al., GCN 8835). Over a period of January 21 23:49:41 - January 22 23:47:00 (UT), the WAM detected about 250 bursts with durations of less than 5 seconds above 5.5 sigma. The most intense event with a T90 duration of 5 seconds was observed on 2009-01-22 08:17:28 (UT), and also detected by INTEGRAL SPI-ACS (Mereghetti et al., GCN 8841). The light curves with 1 sec time resolution for all these bursts are available at the following URL: [link to www.astro.isas.jaxa.jp]


n 2009 Jan 22, the SPI Anti-Coincidence System (ACS) on-board INTEGRAL recorded two bright and long bursts from the AXP 1E1547.0-5408 that recently reactivated (GCN 8833, 8835, 8837, 8838). In both bursts, pulsations at the neutron star period of 2.1 s are clearly visible The start times, duration, and ACS peak count rates (Dt=50 ms) are the following: 1) 06:48:04.2 UT 8.4 s 1.5 10^6 cts/s 2) 08:17:29.4 UT 6.4 s 1.9 10^5 cts/s Burst 1) consists of a short inital spike, lasting about 0.25 s, followed by a pulsating tail. The light curves are available at [link to isdc.unige.ch]