XMM-Newton observed the accreting millisecond pulsar SAX J1808.4-3658 during its 2008 outburst. We present timing and spectral analyses of this observation, in particular the first pulse profile study below 2 keV, and the high-resolution spectral analysis of this source during the outburst. Combined spectral and pulse profile analyses suggest the presence of a strong unpulsed source below 2 keV that strongly reduces the pulsed fraction and a hard pulsed component that generates markedly double peaked profiles at higher energies. We also studied the high-resolution grating spectrum of SAX J1808.4-3658, and found several absorption edges and Oxygen absorption lines with whom we infer, in a model independent way, the interstellar column densities of several elements in the direction of SAX J1808.4-3658.
Two sides of the same spin: tracking optical and radio pulsations of SAX J1808.4-3658 from outburst to quiescence
INAF - Osservatorio Astronomico di Roma(意大利国家天体物理研究所罗马天文台);Sapienza Università di Roma(罗马第一大学);ASI - Agenzia Spaziale Italiana(意大利航天局);INAF - Osservatorio Astronomico di Cagliari(意大利国家天体物理研究所卡利亚里天文台);INAF – Osservatorio Astronomico di Brera(意大利国家天体物理研究所布雷拉天文台);Institute of Space Sciences (ICE, CSIC)(空间科学研究所(西班牙高等科学研究委员会));Institut d’Estudis Espacials de Catalunya (IEEC)(加泰罗尼亚空间研究学院)
A deep X-ray and UV look into the reflaring stage of the accreting millisecond pulsar SAX J1808.4-3658
INAF - Osservatorio Astronomico di Roma(意大利国家天体物理研究所罗马天文台);Sapienza Università di Roma(罗马第一大学);ASI - Agenzia Spaziale Italiana(意大利航天局);INAF - Osservatorio Astronomico di Brera(意大利国家天体物理研究所布雷拉天文台);Università di Palermo(巴勒莫大学);Dipartimento di Fisica e Chimica - Emilio Segrè, Università di Palermo(巴勒莫大学埃米利奥·塞格雷物理化学系);Dipartimento di Fisica, Università degli Studi di Cagliari(卡利亚里大学物理系);INAF/IASF Palermo(意大利国家天体物理研究所帕勒莫空间物理研究所);Institute of Space Sciences (ICE, CSIC)(空间科学研究所(西班牙高等科学研究委员会));Institut d’Estudis Espacials de Catalunya (IEEC)(加泰罗尼亚空间研究学院)
Broadband Timing and Spectral Study of Accreting Millisecond X-ray Pulsar SAX J1808.4$-$3658 during Its 2022 Outburst
Inter-University Centre for Astronomy and Astrophysics (IUCAA)(大学间天文学与天体物理学中心);Universitá degli Studi di Cagliari(卡利亚里大学);Department of Applied Sciences, UPES(印度石油大学应用科学系)