Timing and spectral changes of the Be X-ray transient EXO 0531-6609.2 through high and low state

Tiziana Di Salvo, Cocozza, Gianluca Israel, Rea, Burderi, Di Salvo

Risultato della ricerca: Article

5 Citazioni (Scopus)

Abstract

We report on a spectral and timing analysis of BeppoSAX data of the 13.6 s period transient X-ray pulsar EXO 053109-6609.2. Observations were carried out in March 1997 and October 1998, catching the source during a high and a low emission state, respectively. Correspondingly, the X-ray luminosity is found at a level of 4.2 × 1037 erg s-1 and 1.5 × 1036 erg s-1 in the two states. In the high state the X-ray emission in the energy range 1-100 keV is well fitted by an absorbed power-law with photon index Τ ∼ 1.7 plus a blackbody component with a characteristic temperature of ∼3.5 keV. Moreover, we find evidence of iron emission at ∼6.8 keV, a typical feature in this class of sources but never seen before in the EXO 053109-6609.2 spectrum. In the low state an absorbed power-law with τ ∼ 0.4 is sufficient to fit the 1-10 keV data. During BeppoSAX observations EXO 053109-6609.2 display variations of the pulse profile with the X-ray flux: it showed single peaked and double peaked profiles in the low and high state, respectively. Based on these two observations we infer a spin-up period derivative of -(1.14 ± 0.08) × 10-10 ss-1. By comparing these with other period measurements reported in the literature we find an alternating spin-up and spin-down behaviour that correlates well with the X-ray luminosity.
Lingua originaleEnglish
pagine (da-a)235-239
Numero di pagine5
RivistaASTRONOMY & ASTROPHYSICS
Volume421
Stato di pubblicazionePublished - 2004

Fingerprint

time measurement
x rays
erg
power law
luminosity
profiles
pulsars
spectrum analysis
iron
photons
pulses
energy
temperature

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cita questo

Timing and spectral changes of the Be X-ray transient EXO 0531-6609.2 through high and low state. / Di Salvo, Tiziana; Cocozza; Israel, Gianluca; Rea; Burderi; Di Salvo.

In: ASTRONOMY & ASTROPHYSICS, Vol. 421, 2004, pag. 235-239.

Risultato della ricerca: Article

Di Salvo, Tiziana ; Cocozza ; Israel, Gianluca ; Rea ; Burderi ; Di Salvo. / Timing and spectral changes of the Be X-ray transient EXO 0531-6609.2 through high and low state. In: ASTRONOMY & ASTROPHYSICS. 2004 ; Vol. 421. pagg. 235-239.
@article{104e81f3ae36488bb0a1831b80ba91c9,
title = "Timing and spectral changes of the Be X-ray transient EXO 0531-6609.2 through high and low state",
abstract = "We report on a spectral and timing analysis of BeppoSAX data of the 13.6 s period transient X-ray pulsar EXO 053109-6609.2. Observations were carried out in March 1997 and October 1998, catching the source during a high and a low emission state, respectively. Correspondingly, the X-ray luminosity is found at a level of 4.2 × 1037 erg s-1 and 1.5 × 1036 erg s-1 in the two states. In the high state the X-ray emission in the energy range 1-100 keV is well fitted by an absorbed power-law with photon index Τ ∼ 1.7 plus a blackbody component with a characteristic temperature of ∼3.5 keV. Moreover, we find evidence of iron emission at ∼6.8 keV, a typical feature in this class of sources but never seen before in the EXO 053109-6609.2 spectrum. In the low state an absorbed power-law with τ ∼ 0.4 is sufficient to fit the 1-10 keV data. During BeppoSAX observations EXO 053109-6609.2 display variations of the pulse profile with the X-ray flux: it showed single peaked and double peaked profiles in the low and high state, respectively. Based on these two observations we infer a spin-up period derivative of -(1.14 ± 0.08) × 10-10 ss-1. By comparing these with other period measurements reported in the literature we find an alternating spin-up and spin-down behaviour that correlates well with the X-ray luminosity.",
author = "{Di Salvo}, Tiziana and Cocozza and Gianluca Israel and Rea and Burderi and {Di Salvo}",
year = "2004",
language = "English",
volume = "421",
pages = "235--239",
journal = "ASTRONOMY & ASTROPHYSICS",
issn = "0004-6361",

}

TY - JOUR

T1 - Timing and spectral changes of the Be X-ray transient EXO 0531-6609.2 through high and low state

AU - Di Salvo, Tiziana

AU - Cocozza, null

AU - Israel, Gianluca

AU - Rea, null

AU - Burderi, null

AU - Di Salvo, null

PY - 2004

Y1 - 2004

N2 - We report on a spectral and timing analysis of BeppoSAX data of the 13.6 s period transient X-ray pulsar EXO 053109-6609.2. Observations were carried out in March 1997 and October 1998, catching the source during a high and a low emission state, respectively. Correspondingly, the X-ray luminosity is found at a level of 4.2 × 1037 erg s-1 and 1.5 × 1036 erg s-1 in the two states. In the high state the X-ray emission in the energy range 1-100 keV is well fitted by an absorbed power-law with photon index Τ ∼ 1.7 plus a blackbody component with a characteristic temperature of ∼3.5 keV. Moreover, we find evidence of iron emission at ∼6.8 keV, a typical feature in this class of sources but never seen before in the EXO 053109-6609.2 spectrum. In the low state an absorbed power-law with τ ∼ 0.4 is sufficient to fit the 1-10 keV data. During BeppoSAX observations EXO 053109-6609.2 display variations of the pulse profile with the X-ray flux: it showed single peaked and double peaked profiles in the low and high state, respectively. Based on these two observations we infer a spin-up period derivative of -(1.14 ± 0.08) × 10-10 ss-1. By comparing these with other period measurements reported in the literature we find an alternating spin-up and spin-down behaviour that correlates well with the X-ray luminosity.

AB - We report on a spectral and timing analysis of BeppoSAX data of the 13.6 s period transient X-ray pulsar EXO 053109-6609.2. Observations were carried out in March 1997 and October 1998, catching the source during a high and a low emission state, respectively. Correspondingly, the X-ray luminosity is found at a level of 4.2 × 1037 erg s-1 and 1.5 × 1036 erg s-1 in the two states. In the high state the X-ray emission in the energy range 1-100 keV is well fitted by an absorbed power-law with photon index Τ ∼ 1.7 plus a blackbody component with a characteristic temperature of ∼3.5 keV. Moreover, we find evidence of iron emission at ∼6.8 keV, a typical feature in this class of sources but never seen before in the EXO 053109-6609.2 spectrum. In the low state an absorbed power-law with τ ∼ 0.4 is sufficient to fit the 1-10 keV data. During BeppoSAX observations EXO 053109-6609.2 display variations of the pulse profile with the X-ray flux: it showed single peaked and double peaked profiles in the low and high state, respectively. Based on these two observations we infer a spin-up period derivative of -(1.14 ± 0.08) × 10-10 ss-1. By comparing these with other period measurements reported in the literature we find an alternating spin-up and spin-down behaviour that correlates well with the X-ray luminosity.

UR - http://hdl.handle.net/10447/24513

UR - https://www.aanda.org/articles/aa/ps/2004/25/aa0685.ps.gz

M3 - Article

VL - 421

SP - 235

EP - 239

JO - ASTRONOMY & ASTROPHYSICS

JF - ASTRONOMY & ASTROPHYSICS

SN - 0004-6361

ER -