Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags
<jats:title>ABSTRACT</jats:title> <jats:p>We present a new release of the reltrans model to fit the complex cross-spectrum of accreting black holes as a function of energy. The model accounts for continuum lags and reverberation lags self-consistently in order to co...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Oxford University Press (OUP)
2022
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| Online Access: | https://hdl.handle.net/1721.1/141978 |
| _version_ | 1826217185281835008 |
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| author | Mastroserio, Guglielmo Ingram, Adam Wang, Jingyi García, Javier A van der Klis, Michiel Cavecchi, Yuri Connors, Riley Dauser, Thomas Harrison, Fiona Kara, Erin König, Ole Lucchini, Matteo |
| author2 | MIT Kavli Institute for Astrophysics and Space Research |
| author_facet | MIT Kavli Institute for Astrophysics and Space Research Mastroserio, Guglielmo Ingram, Adam Wang, Jingyi García, Javier A van der Klis, Michiel Cavecchi, Yuri Connors, Riley Dauser, Thomas Harrison, Fiona Kara, Erin König, Ole Lucchini, Matteo |
| author_sort | Mastroserio, Guglielmo |
| collection | MIT |
| description | <jats:title>ABSTRACT</jats:title>
<jats:p>We present a new release of the reltrans model to fit the complex cross-spectrum of accreting black holes as a function of energy. The model accounts for continuum lags and reverberation lags self-consistently in order to consider the widest possible range of X-ray variability time-scales. We introduce a more self-consistent treatment of the reverberation lags, accounting for how the time variations of the illuminating flux change the ionization level of the accretion disc. This process varies the shape of the reflection spectrum in time causing an additional source of lags besides the light crossing delay. We also consider electron densities in the accretion disc up to 1020 cm−3, which are found in most of the stellar mass black holes and in some active galactic nuclei. These high densities increase the amplitude of the reverberation lags below 1 keV since the reflection flux enhances in the same energy range. In addition, we investigate the properties of hard lags produced by variations in the power-law index of the continuum spectrum, which can be interpreted as due to roughly $3{{\ \rm per\ cent}}$ variability in the corona’s optical depth and temperature. As a test case, we simultaneously fit the lag-energy spectra in a wide range of Fourier frequency for the black hole candidate MAXI J1820+0701820 observed with NICER. The best fit shows how the reverberation lags contribute even at the longer time-scales where the hard lags are important. This proves the importance of modelling these two lags together and self-consistently in order to constrain the parameters of the system.</jats:p> |
| first_indexed | 2024-09-23T16:59:22Z |
| format | Article |
| id | mit-1721.1/141978 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T16:59:22Z |
| publishDate | 2022 |
| publisher | Oxford University Press (OUP) |
| record_format | dspace |
| spelling | mit-1721.1/1419782023-01-20T16:37:45Z Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags Mastroserio, Guglielmo Ingram, Adam Wang, Jingyi García, Javier A van der Klis, Michiel Cavecchi, Yuri Connors, Riley Dauser, Thomas Harrison, Fiona Kara, Erin König, Ole Lucchini, Matteo MIT Kavli Institute for Astrophysics and Space Research <jats:title>ABSTRACT</jats:title> <jats:p>We present a new release of the reltrans model to fit the complex cross-spectrum of accreting black holes as a function of energy. The model accounts for continuum lags and reverberation lags self-consistently in order to consider the widest possible range of X-ray variability time-scales. We introduce a more self-consistent treatment of the reverberation lags, accounting for how the time variations of the illuminating flux change the ionization level of the accretion disc. This process varies the shape of the reflection spectrum in time causing an additional source of lags besides the light crossing delay. We also consider electron densities in the accretion disc up to 1020 cm−3, which are found in most of the stellar mass black holes and in some active galactic nuclei. These high densities increase the amplitude of the reverberation lags below 1 keV since the reflection flux enhances in the same energy range. In addition, we investigate the properties of hard lags produced by variations in the power-law index of the continuum spectrum, which can be interpreted as due to roughly $3{{\ \rm per\ cent}}$ variability in the corona’s optical depth and temperature. As a test case, we simultaneously fit the lag-energy spectra in a wide range of Fourier frequency for the black hole candidate MAXI J1820+0701820 observed with NICER. The best fit shows how the reverberation lags contribute even at the longer time-scales where the hard lags are important. This proves the importance of modelling these two lags together and self-consistently in order to constrain the parameters of the system.</jats:p> 2022-04-20T16:21:03Z 2022-04-20T16:21:03Z 2021 2022-04-20T16:18:06Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/141978 Mastroserio, Guglielmo, Ingram, Adam, Wang, Jingyi, García, Javier A, van der Klis, Michiel et al. 2021. "Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags." Monthly Notices of the Royal Astronomical Society, 507 (1). en 10.1093/MNRAS/STAB2056 Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv |
| spellingShingle | Mastroserio, Guglielmo Ingram, Adam Wang, Jingyi García, Javier A van der Klis, Michiel Cavecchi, Yuri Connors, Riley Dauser, Thomas Harrison, Fiona Kara, Erin König, Ole Lucchini, Matteo Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags |
| title | Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags |
| title_full | Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags |
| title_fullStr | Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags |
| title_full_unstemmed | Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags |
| title_short | Modelling correlated variability in accreting black holes: the effect of high density and variable ionization on reverberation lags |
| title_sort | modelling correlated variability in accreting black holes the effect of high density and variable ionization on reverberation lags |
| url | https://hdl.handle.net/1721.1/141978 |
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