SUMMARY OF PROPOSAL 73009
ISTITUTO DI FISICA COSMICA 'G.OCCHIALINI'
V.BASSINI 15
MILANO
ITALY I-20133
Tel: +39 02 23699323 Fax: +39 02 2362946
Medium: CD ROM
Subject: X-RAY BINARIES
MONITORING OF THE ANOMALOUS X-RAY PULSAR 4U0142+61 WITH ASCA
ABSTRACT
We propose a systematic monitoring of 4U0142+61, the brightest member of the small class of Anomalous (or 6-sec) X-ray Pulsars. To accurately assess its variability properties, on timescales from several hours to a few days, a set of directly comparable observations obtained with the same instrument and analyzed in a consistent way is necessary. Detection of variability (and possibly related Pdot changes), or strong upper limits, would provide crucial information to discriminate between accretion based models and other mechanisms recently proposed to explain the X-ray emission from AXP, like, e.g., magnetic field decay and/or internal cooling of isolated neutron stars. The imaging capabilities of ASCA are required to avoid contamination from a nearby variable source.
CO-INVESTIGATORS
| CO-I NAME | INSTITUTE | COUNTRY |
|---|
| GIANLUCA ISRAEL | OSS. ASTRON. ROMA | ITALY |
| SERGIO CAMPANA | OSS. ASTRON. MERATE | ITALY |
| LUIGI STELLA | OSS. ASTRON. ROMA | ITALY |
TARGETS
| TARGET NAME | PRI | RA | DEC | TIME | TC | OFF | GIS | SIS CNT | OBS |
|---|
| 1)4U 0142+61 | A | 26.5917 | 61.7511 | 120 ks | Y | Y | P | 5.50000 | 6 |
TARGET 1
THE SPACING BETWEEN OBSERVATIONS DOES NOT NEED TO BE REGULAR. IT WOULD BE BETTER TO CARRY OUT ALL THE OBSERVATIONS WITHIN A SINGLE VISIBILITY PERIOD. INTERVALS OF 2 TO 7 DAYS WOULD BE APPROPRIATE.
MONITORED OBSERVATION:
Min. Interval: 170.000ksecMax. Interval: 600.000 ksec