|Proposal Number||Subject Category||PI Name||Chandra Time||Title|
|10300001||WD and NS Binaries||Wolfgang Pietsch||Resolving short supersoft source states of optical novae in the core of M31|
|10500002||Supernovae and Supernova remnants||Jules Halpern||Measuring the Magnetic Fields of Central Compact Objects in Supernova Remnants|
Subject Category: WD and NS Binaries
Proposal Number: 10300001
Title: Resolving short supersoft source states of optical novae in the core of M31
PI Name: Wolfgang Pietsch
We propose to continue the monitoring of the M31 core with five 23ks XMM-Newton EPIC and five 20ks Chandra HRC-I observations equally distributed from Nov 2008 to mid Feb 2009 to determine additional light curves for short supersoft source (SSS) states of optical novae. SSS states with <100 d duration indicate accreting massive white dwarfs. They are proposed as SN Ia progenitors and determining their frequency is very important. We will correlate detected sources with novae from optical monitoring. With a nova rate in the field of ~25/yr and SSS states lasting from weeks to years we will follow light curves of many novae. Durations of the nova SSS state will allow us to constrain envelope and whitedwarf masses. We will also monitor time variability of ~200 M31 centre X-ray sources (mostly XRBs).
Subject Category: Supernovae and Supernova remnants
Proposal Number: 10500002
Title: Measuring the Magnetic Fields of Central Compact Objects in Supernova Remnants
PI Name: Jules Halpern
X-ray timing studies of two X-ray pulsars in SNRs have detected no braking of their rotation, implying upper limits of 3E11 G on their surface dipole fields, well below those of ordinary young pulsars. We proposed that weak B-fields related to slow natal spin may be the physical basis of the class of Central Compact Objects (CCOs), including the unseen pulsar in SN 1987A. This proposal leverages existing timing data on CCO pulsars to determine if they are spinning down and, if so, to measure their magnetic fields by obtaining coherent timing solutions linking all previous data. Fields as small as 1E10 G can be measured in this way. Alternatively, accretion of supernova debris through a fallback disk may be occurring, which would be detectable as torque noise.