1999A&A...345..117K


Query : 1999A&A...345..117K

1999A&A...345..117K - Astronomy and Astrophysics, volume 345, 117-120 (1999/5-1)

The recent pulse period evolution of SMC X-1.

KAHABKA P. and LI X.-D.

Abstract (from CDS):

We report observations of SMC X-1 in three new high-intensity states with ROSAT HRI in December 1995, May 1997, and March 1998 in which pulsations with a period of 0.70769 (±0.00006)s, 0.70706 (±0.00001)s, and 0.706707 (±0.00001)s respectively were detected. Combining the pulse periods from observations with ROSAT PSPC in high-intensity states in October 1991 and March 1998, respectively, we obtain the spin-up rate of the pulsar in recent 6.5 years, -{dot}(P)=(1.18±0.06)x10–11s/s, consistent with the average spin-up rate -{dot}(P)=1.2x10–11s/s determined from previous measurements indicating that the stable spin-up has continued. Pulsations with a period of 0.709103 (±0.000003)s were also detected ∼2 weeks after an X-ray turn-off during an X-ray low-intensity state in October 1991, and the period derivative derived within ∼10days is -{dot}(P)≃(1.1±0.7)x10–11s/s. This is consistent with a constant accretion torque in sign and magnitude. The magnitude of the magnetic moment of the pulsar is discussed based on different description of the apparent spin-up behavior.

Abstract Copyright:

Journal keyword(s): accretion, accretion disks - stars: individual: SMC X-1 (SMC) - stars: magnetic fields - stars: neutron - stars: rotation - X-rays: stars

Simbad objects: 5

goto View the references in ADS

Number of rows : 5
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 10194 1
2 SK 160 HXB 01 17 05.1457288392 -73 26 36.014808156 12.23 13.00 13.15   13.17 O9.7Ia+ 821 0
3 [MA93] 1845 HXB 01 17 40.1630558064 -73 30 50.523690888 13.30 14.14 14.18   14.09 B1-3(II)e 52 0
4 V* V779 Cen HXB 11 21 15.0920532528 -60 37 25.630264596   14.4 12.27     O9III/Veq 1025 0
5 3FHL J1746.2-2852 LXB 17 44 33.09 -28 44 27.0           ~ 511 0

To bookmark this query, right click on this link: simbad:objects in 1999A&A...345..117K and select 'bookmark this link' or equivalent in the popup menu


2022.05.23-10:05:47

© Université de Strasbourg/CNRS

    • Contact