Utilizza questo identificativo per citare o creare un link a questo documento:
http://hdl.handle.net/20.500.12386/29640
Titolo: | The transitional millisecond pulsar IGR J18245-2452 during its 2013 outburst at X-rays and soft gamma-rays | Autori: | De Falco, V. Kuiper, L. Bozzo, E. Ferrigno, C. Poutanen, J. STELLA, Luigi Falanga, M. |
Data pubblicazione: | 2017 | Rivista: | ASTRONOMY & ASTROPHYSICS | Numero: | 603 | Da pagina:: | A16 | Abstract: | IGR J18245-2452/PSR J1824-2452I is one of the rare transitional accreting millisecond X-ray pulsars, showing direct evidence of switches between states of rotation-powered radio pulsations and accretion-powered X-ray pulsations, dubbed transitional pulsars. IGR J18245-2452 with a spin frequency of 254.3 Hz is the only transitional pulsar so far to have shown a full accretion episode, reaching an X-ray luminosity of 10<SUP>37</SUP> erg s<SUP>-1</SUP> permitting its discovery with INTEGRAL in 2013. In this paper, we report on a detailed analysis of the data collected with the IBIS/ISGRI and the two JEM-X monitors on-board INTEGRAL at the time of the 2013 outburst. We make use of some complementary data obtained with the instruments on-board XMM-Newton and Swift in order to perform the averaged broad-band spectral analysis of the source in the energy range 0.4-250 keV. We have found that this spectrum is the hardest among the accreting millisecond X-ray pulsars. We improved the ephemeris, now valid across its full outburst, and report the detection of pulsed emission up to 60 keV in both the ISGRI (10.9σ) and Fermi/GBM (5.9σ) bandpass. The alignment of the ISGRI and Fermi GBM 20-60 keV pulse profiles are consistent at a 25 μs level. We compared the pulse profiles obtained at soft X-rays with XMM-Newton with the soft γ-ray ones, and derived the pulsed fractions of the fundamental and first harmonic, as well as the time lag of the fundamental harmonic, up to 150 μs, as a function of energy. We report on a thermonuclear X-ray burst detected with INTEGRAL, and using the properties of the previously type-I X-ray burst, we show that all these events are powered primarily by helium ignited at a depth of y<SUB>ign</SUB> ≈ 2.7 × 10<SUP>8</SUP> g cm{<SUP>-2</SUP>}. For such a helium burst the estimated recurrence time of ∆t<SUB>rec</SUB> ≈ 5.6 d is in agreement with the observations. | URI: | http://hdl.handle.net/20.500.12386/29640 | URL: | https://www.aanda.org/articles/aa/abs/2017/07/aa30600-17/aa30600-17.html | ISSN: | 0004-6361 | DOI: | 10.1051/0004-6361/201730600 | Bibcode ADS: | 2017A&A...603A..16D | Fulltext: | open |
È visualizzato nelle collezioni: | 1.01 Articoli in rivista |
File in questo documento:
File | Descrizione | Dimensioni | Formato | |
---|---|---|---|---|
aa30600-17.pdf | PDF editoriale | 827.54 kB | Adobe PDF | Visualizza/apri |
Page view(s)
37
controllato il 19-apr-2024
Download(s)
10
controllato il 19-apr-2024
Google ScholarTM
Check
Altmetric
Altmetric
Tutti i documenti in DSpace sono pubblicati ad Accesso Aperto, salvo diversa indicazione per alcuni documenti specifici.