Search for absorption edges in superexpansion bursts
Abstract
Our goal is to measure with the LETGS a series of bright type-I X-ray bursts with strong photospheric radius expansion ('superexpansion'), search for absorption edges due to the ashes of nuclear burning and, if succesful, attempt a measurement of the gravitational redshift. The target, 4U 1820-30, is an ultracompact X-ray binary whose bursts are known to consistently show strong expansion. The bursts only occur in the quasi-periodic low accretion states. We request a quick TOO, to be triggered by either RXTE-ASM or ISS-MAXI, with a total exposure time of 100 ks to obtain the detection of about 10 bursts.
- Publication:
-
Chandra Proposal
- Pub Date:
- September 2010
- Bibcode:
- 2010cxo..prop.3085I