Updated orbital ephemeris of the ADC source X 1822-371: A stable orbital expansion over 40 years

Rosario Iaria, Simona Michela Mazzola, Tiziana Di Salvo, Alessio Marino, Riggio, Sanna, Tailo, Gambino, Marino, Burderi

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Abstract

Aims. Source X 1822-371 is an eclipsing compact binary system with a period close to 5.57 h and an orbital period derivative Porb of 1:51(7) ×10-10 ss-1. The very high value of Porb is compatible with a super-Eddington mass transfer rate from the companion star, as suggested by X-ray and optical data. The XMM-Newton observation taken in 2017 allows us to update the orbital ephemeris and verify whether the orbital period derivative has been stable over the past 40 yr. Methods. We added two new values obtained from the Rossi-XTE (RXTE) and XMM-Newton observations performed in 2011 and 2017, respectively, to the X-ray eclipse arrival times from 1977 to 2008. We estimated the number of orbital cycles and the delays of our eclipse arrival times spanning 40 yr, using as reference time the eclipse arrival time obtained from the RXTE observation taken in 1996. Results. Fitting the delays with a quadratic model, we found an orbital period Porb = 5:57062957(20) h and a Porb value of 1:475(54)× 10-10 s s-1. The addition of a cubic term to the model does not significantly improve the fit quality. We also determined a spin-period value of Pspin = 0:5915669(4) s and its first derivative Pspin = -2:595(11) × 10-12 s s-1. Conclusions. Our results confirm the scenario of a super-Eddington mass transfer rate; we also exclude a gravitational coupling between the orbit and the change in the oblateness of the companion star triggered by the nuclear luminosity of the companion star.
Lingua originaleEnglish
pagine (da-a)L12-
Numero di pagine5
RivistaASTRONOMY & ASTROPHYSICS
Volume625
Stato di pubblicazionePublished - 2019

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companion stars
eclipses
orbitals
expansion
arrivals
XMM-Newton telescope
newton
mass transfer
x rays
luminosity
orbits
cycles

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cita questo

@article{263bcf3f57ce4f318b5907675d354748,
title = "Updated orbital ephemeris of the ADC source X 1822-371: A stable orbital expansion over 40 years",
abstract = "Aims. Source X 1822-371 is an eclipsing compact binary system with a period close to 5.57 h and an orbital period derivative Porb of 1:51(7) ×10-10 ss-1. The very high value of Porb is compatible with a super-Eddington mass transfer rate from the companion star, as suggested by X-ray and optical data. The XMM-Newton observation taken in 2017 allows us to update the orbital ephemeris and verify whether the orbital period derivative has been stable over the past 40 yr. Methods. We added two new values obtained from the Rossi-XTE (RXTE) and XMM-Newton observations performed in 2011 and 2017, respectively, to the X-ray eclipse arrival times from 1977 to 2008. We estimated the number of orbital cycles and the delays of our eclipse arrival times spanning 40 yr, using as reference time the eclipse arrival time obtained from the RXTE observation taken in 1996. Results. Fitting the delays with a quadratic model, we found an orbital period Porb = 5:57062957(20) h and a Porb value of 1:475(54)× 10-10 s s-1. The addition of a cubic term to the model does not significantly improve the fit quality. We also determined a spin-period value of Pspin = 0:5915669(4) s and its first derivative Pspin = -2:595(11) × 10-12 s s-1. Conclusions. Our results confirm the scenario of a super-Eddington mass transfer rate; we also exclude a gravitational coupling between the orbit and the change in the oblateness of the companion star triggered by the nuclear luminosity of the companion star.",
keywords = "Eclipses, Ephemerides, Stars: Individual: X 1822-371, Stars: neutron, X-rays: Binaries",
author = "Rosario Iaria and Mazzola, {Simona Michela} and {Di Salvo}, Tiziana and Alessio Marino and Riggio and Sanna and Tailo and Gambino and Marino and Burderi",
year = "2019",
language = "English",
volume = "625",
pages = "L12--",
journal = "ASTRONOMY & ASTROPHYSICS",
issn = "0004-6361",

}

TY - JOUR

T1 - Updated orbital ephemeris of the ADC source X 1822-371: A stable orbital expansion over 40 years

AU - Iaria, Rosario

AU - Mazzola, Simona Michela

AU - Di Salvo, Tiziana

AU - Marino, Alessio

AU - Riggio, null

AU - Sanna, null

AU - Tailo, null

AU - Gambino, null

AU - Marino, null

AU - Burderi, null

PY - 2019

Y1 - 2019

N2 - Aims. Source X 1822-371 is an eclipsing compact binary system with a period close to 5.57 h and an orbital period derivative Porb of 1:51(7) ×10-10 ss-1. The very high value of Porb is compatible with a super-Eddington mass transfer rate from the companion star, as suggested by X-ray and optical data. The XMM-Newton observation taken in 2017 allows us to update the orbital ephemeris and verify whether the orbital period derivative has been stable over the past 40 yr. Methods. We added two new values obtained from the Rossi-XTE (RXTE) and XMM-Newton observations performed in 2011 and 2017, respectively, to the X-ray eclipse arrival times from 1977 to 2008. We estimated the number of orbital cycles and the delays of our eclipse arrival times spanning 40 yr, using as reference time the eclipse arrival time obtained from the RXTE observation taken in 1996. Results. Fitting the delays with a quadratic model, we found an orbital period Porb = 5:57062957(20) h and a Porb value of 1:475(54)× 10-10 s s-1. The addition of a cubic term to the model does not significantly improve the fit quality. We also determined a spin-period value of Pspin = 0:5915669(4) s and its first derivative Pspin = -2:595(11) × 10-12 s s-1. Conclusions. Our results confirm the scenario of a super-Eddington mass transfer rate; we also exclude a gravitational coupling between the orbit and the change in the oblateness of the companion star triggered by the nuclear luminosity of the companion star.

AB - Aims. Source X 1822-371 is an eclipsing compact binary system with a period close to 5.57 h and an orbital period derivative Porb of 1:51(7) ×10-10 ss-1. The very high value of Porb is compatible with a super-Eddington mass transfer rate from the companion star, as suggested by X-ray and optical data. The XMM-Newton observation taken in 2017 allows us to update the orbital ephemeris and verify whether the orbital period derivative has been stable over the past 40 yr. Methods. We added two new values obtained from the Rossi-XTE (RXTE) and XMM-Newton observations performed in 2011 and 2017, respectively, to the X-ray eclipse arrival times from 1977 to 2008. We estimated the number of orbital cycles and the delays of our eclipse arrival times spanning 40 yr, using as reference time the eclipse arrival time obtained from the RXTE observation taken in 1996. Results. Fitting the delays with a quadratic model, we found an orbital period Porb = 5:57062957(20) h and a Porb value of 1:475(54)× 10-10 s s-1. The addition of a cubic term to the model does not significantly improve the fit quality. We also determined a spin-period value of Pspin = 0:5915669(4) s and its first derivative Pspin = -2:595(11) × 10-12 s s-1. Conclusions. Our results confirm the scenario of a super-Eddington mass transfer rate; we also exclude a gravitational coupling between the orbit and the change in the oblateness of the companion star triggered by the nuclear luminosity of the companion star.

KW - Eclipses

KW - Ephemerides

KW - Stars: Individual: X 1822-371

KW - Stars: neutron

KW - X-rays: Binaries

UR - http://hdl.handle.net/10447/387758

UR - https://www.aanda.org/

M3 - Article

VL - 625

SP - L12-

JO - ASTRONOMY & ASTROPHYSICS

JF - ASTRONOMY & ASTROPHYSICS

SN - 0004-6361

ER -