Proposal Details - 0720027
The stability of the new hard X-ray tail of AXP 1E 1547.0-5408 (Den Hartog)

Proposal Abstract

On Jan. 22, 2009 a huge outburst of 1E1547.0-5408 commenced accompanied by strongly increased short-duration burst activity. INTEGRAL detected emission up to ~150 keV during 2 ToO observations, one performed for about 100 ks on Jan. 24-25, 2009 and a second for 600 ks from Jan. 28 to Feb. 8, 2009.Till this outburst no INTEGRAL detection could be established. Now, for the first time INTEGRAL discovered the turn-on of hard (photon index ~ 1.3; pulsed) emission. During the second INTEGRAL ToO the source was still (very) bright between 20 and 150 keV with no signs of fading. Its flux decreased only 30% compared to the first ToO measurement. The biggest question therefore is whether this hard tail will fade or will remain stable like the persistent hard X-ray emission from the other three AXPs showing hard spectral tails? Therefore we propose to reobserve 1E1547.0-5408 for 2 revolutions (~400 ks) during AO7.

Observation Strategy (Recommended by TAC)

Total of 400 ks in the standard 5x5 dithering mode centred on RA, Dec = 237.725, -54.307 (l, b = 327.237, -0.132). A first exposure of 200 ks will be scheduled as a normal observation in AO7. A second exposure of 200 ksec will be done as a TOO observation, depending on the source behaviour during the first observation.

Proposal grade: A

Data Rights (Recommended by TAC)

The TAC has allocated the following specific data rights to this proposal: AXP 1E 1547.0-5408.

Exposure Map

The exposure maps are in galactic coordinates and units of ksec, and the colour scale is indicated at the bottom. The green lines provide the 100 ksec contour.