Investigating the Superorbital Modulations in 4U 1909 + 07, IGR J16418-4532, and IGR J16479-4514 with Swift XRT, BAT, and NuSTAR Observations
A puzzling variety of superorbital modulations has been discovered in several supergiant high mass X-ray binaries (sgHMXBs). To investigate the mechanisms driving these superorbital modulations, we have analyzed long-term Neil Gehrels Swift Observatory (Swift) Burst Alert Telescope (BAT) observation...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acbc19 |
| _version_ | 1827829931690688512 |
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| author | Nazma Islam Robin H. D. Corbet Joel B. Coley Katja Pottschmidt Felix Fuerst |
| author_facet | Nazma Islam Robin H. D. Corbet Joel B. Coley Katja Pottschmidt Felix Fuerst |
| author_sort | Nazma Islam |
| collection | DOAJ |
| description | A puzzling variety of superorbital modulations has been discovered in several supergiant high mass X-ray binaries (sgHMXBs). To investigate the mechanisms driving these superorbital modulations, we have analyzed long-term Neil Gehrels Swift Observatory (Swift) Burst Alert Telescope (BAT) observations of three sgHMXBs: 4U 1909 + 07, IGR J16418–4532, and IGR J16479–4514, and constructed their dynamic power spectra and superorbital intensity profiles. These Swift BAT observations are complemented by pointed Swift X-ray Telescope (XRT) and Nuclear Spectroscopic Telescope Array (NuSTAR) observations performed near the predicted maximum and minimum phase of a single superorbital cycle for each of these sources. The BAT dynamic power spectra show changes in the strength of the superorbital modulation on timescales of years, with either the peak at the fundamental frequency and/or the second harmonic present at different times for all three sources. The pointed Swift XRT and NuSTAR observations show no significant differences between the pulse profiles and spectral parameters at the superorbital maximum and minimum phase. This is likely due to the fact the superorbital modulation had weakened significantly during the times when the NuSTAR observations were carried out for all three sources. The results from the Swift XRT, BAT, and NuSTAR analysis indicate the possible presence of multiple corotating interaction regions (CIRs) in the stellar winds of the supergiant stars, although a structured stellar wind from the supergiant star due to tidal oscillations cannot be ruled out. |
| first_indexed | 2024-03-12T04:13:19Z |
| format | Article |
| id | doaj.art-d7d0324cebed445fa189320c53695e42 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T04:13:19Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-d7d0324cebed445fa189320c53695e422023-09-03T10:52:55ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194814510.3847/1538-4357/acbc19Investigating the Superorbital Modulations in 4U 1909 + 07, IGR J16418-4532, and IGR J16479-4514 with Swift XRT, BAT, and NuSTAR ObservationsNazma Islam0https://orcid.org/0000-0002-2413-9301Robin H. D. Corbet1https://orcid.org/0000-0002-3396-651XJoel B. Coley2https://orcid.org/0000-0001-7532-8359Katja Pottschmidt3https://orcid.org/0000-0002-4656-6881Felix Fuerst4https://orcid.org/0000-0003-0388-0560Center for Space Science and Technology, University of Maryland , Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA ; nislam@umbc.edu; X-ray Astrophysics Laboratory, NASA Goddard Space Flight Center , Greenbelt, MD 20771, USAX-ray Astrophysics Laboratory, NASA Goddard Space Flight Center , Greenbelt, MD 20771, USA; CRESST and CSST, University of Maryland , Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA; Maryland Institute College of Art , 1300 W Mt Royal Avenue, Baltimore, MD 21217, USACRESST/Department of Physics and Astronomy, Howard University , Washington DC 20059, USA; Code 661 Astroparticle Physics Laboratory , NASA Goddard Space Flight Center, Greenbelt, MD 20771, USACRESST and CSST, University of Maryland , Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA; Code 661 Astroparticle Physics Laboratory , NASA Goddard Space Flight Center, Greenbelt, MD 20771, USAQuasar Science Resources S.L for European Space Agency (ESA) , European Space Astronomy Centre (ESAC), Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, SpainA puzzling variety of superorbital modulations has been discovered in several supergiant high mass X-ray binaries (sgHMXBs). To investigate the mechanisms driving these superorbital modulations, we have analyzed long-term Neil Gehrels Swift Observatory (Swift) Burst Alert Telescope (BAT) observations of three sgHMXBs: 4U 1909 + 07, IGR J16418–4532, and IGR J16479–4514, and constructed their dynamic power spectra and superorbital intensity profiles. These Swift BAT observations are complemented by pointed Swift X-ray Telescope (XRT) and Nuclear Spectroscopic Telescope Array (NuSTAR) observations performed near the predicted maximum and minimum phase of a single superorbital cycle for each of these sources. The BAT dynamic power spectra show changes in the strength of the superorbital modulation on timescales of years, with either the peak at the fundamental frequency and/or the second harmonic present at different times for all three sources. The pointed Swift XRT and NuSTAR observations show no significant differences between the pulse profiles and spectral parameters at the superorbital maximum and minimum phase. This is likely due to the fact the superorbital modulation had weakened significantly during the times when the NuSTAR observations were carried out for all three sources. The results from the Swift XRT, BAT, and NuSTAR analysis indicate the possible presence of multiple corotating interaction regions (CIRs) in the stellar winds of the supergiant stars, although a structured stellar wind from the supergiant star due to tidal oscillations cannot be ruled out.https://doi.org/10.3847/1538-4357/acbc19High mass x-ray binary starsAstronomy data analysisStellar winds |
| spellingShingle | Nazma Islam Robin H. D. Corbet Joel B. Coley Katja Pottschmidt Felix Fuerst Investigating the Superorbital Modulations in 4U 1909 + 07, IGR J16418-4532, and IGR J16479-4514 with Swift XRT, BAT, and NuSTAR Observations The Astrophysical Journal High mass x-ray binary stars Astronomy data analysis Stellar winds |
| title | Investigating the Superorbital Modulations in 4U 1909 + 07, IGR J16418-4532, and IGR J16479-4514 with Swift XRT, BAT, and NuSTAR Observations |
| title_full | Investigating the Superorbital Modulations in 4U 1909 + 07, IGR J16418-4532, and IGR J16479-4514 with Swift XRT, BAT, and NuSTAR Observations |
| title_fullStr | Investigating the Superorbital Modulations in 4U 1909 + 07, IGR J16418-4532, and IGR J16479-4514 with Swift XRT, BAT, and NuSTAR Observations |
| title_full_unstemmed | Investigating the Superorbital Modulations in 4U 1909 + 07, IGR J16418-4532, and IGR J16479-4514 with Swift XRT, BAT, and NuSTAR Observations |
| title_short | Investigating the Superorbital Modulations in 4U 1909 + 07, IGR J16418-4532, and IGR J16479-4514 with Swift XRT, BAT, and NuSTAR Observations |
| title_sort | investigating the superorbital modulations in 4u 1909 07 igr j16418 4532 and igr j16479 4514 with swift xrt bat and nustar observations |
| topic | High mass x-ray binary stars Astronomy data analysis Stellar winds |
| url | https://doi.org/10.3847/1538-4357/acbc19 |
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