Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750

In this letter, we present the results from subsequent X-ray and UV observations of the nuclear transient eRASSt J045650.3-203750 (hereafter, J0456-20). We detected five repeating X-ray and UV flares from J0456-20, marking it as one of the most promising repeating partial tidal disruption event (pTD...

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Main Authors: Liu, Z., Ryu, T., Goodwin, Andrew, Rau, A., Homan, D., Krumpe, M., Merloni, A., Grotova, I., Anderson, Gemma, Malyali, A., Miller-Jones, James
Format: Journal Article
Published: 2024
Online Access:http://purl.org/au-research/grants/arc/DP200102471
http://hdl.handle.net/20.500.11937/96139
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author Liu, Z.
Ryu, T.
Goodwin, Andrew
Rau, A.
Homan, D.
Krumpe, M.
Merloni, A.
Grotova, I.
Anderson, Gemma
Malyali, A.
Miller-Jones, James
author_facet Liu, Z.
Ryu, T.
Goodwin, Andrew
Rau, A.
Homan, D.
Krumpe, M.
Merloni, A.
Grotova, I.
Anderson, Gemma
Malyali, A.
Miller-Jones, James
author_sort Liu, Z.
building Curtin Institutional Repository
collection Online Access
description In this letter, we present the results from subsequent X-ray and UV observations of the nuclear transient eRASSt J045650.3-203750 (hereafter, J0456-20). We detected five repeating X-ray and UV flares from J0456-20, marking it as one of the most promising repeating partial tidal disruption event (pTDE) candidates. More importantly, we also found rapid changes in the recurrence time, Trecur, of the X-ray flares by modelling the long-term X-ray light curve of J0456-20. We found that Trecur first decreased rapidly from about 300 days to around 230 days. It continued to decrease to around 190 days with an indication of a constant Trecur, as evidenced by the latest three cycles. Our hydrodynamic simulations suggest that, in the repeating pTDE scenario, such a rapid evolution of Trecur could be reproduced if the original star is a 1 M⊙ main sequence star near the terminal age, losing nearly 80- 90% of its mass during the initial encounter with a supermassive black hole (SMBH) of a mass around 105 M⊙. The inferred mass loss of 0.8- 0.9 M⊙ is higher than the estimated value of around 0.13 M⊙ drawn from observations, which could be explained if the radiation efficiency is low (i.e. ≪0.1). Our results indicate that repeating pTDEs could be effective tools for exploring the dynamics around SMBHs beyond our own Galaxy.
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spelling curtin-20.500.11937-961392024-11-07T01:22:42Z Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750 Liu, Z. Ryu, T. Goodwin, Andrew Rau, A. Homan, D. Krumpe, M. Merloni, A. Grotova, I. Anderson, Gemma Malyali, A. Miller-Jones, James In this letter, we present the results from subsequent X-ray and UV observations of the nuclear transient eRASSt J045650.3-203750 (hereafter, J0456-20). We detected five repeating X-ray and UV flares from J0456-20, marking it as one of the most promising repeating partial tidal disruption event (pTDE) candidates. More importantly, we also found rapid changes in the recurrence time, Trecur, of the X-ray flares by modelling the long-term X-ray light curve of J0456-20. We found that Trecur first decreased rapidly from about 300 days to around 230 days. It continued to decrease to around 190 days with an indication of a constant Trecur, as evidenced by the latest three cycles. Our hydrodynamic simulations suggest that, in the repeating pTDE scenario, such a rapid evolution of Trecur could be reproduced if the original star is a 1 M⊙ main sequence star near the terminal age, losing nearly 80- 90% of its mass during the initial encounter with a supermassive black hole (SMBH) of a mass around 105 M⊙. The inferred mass loss of 0.8- 0.9 M⊙ is higher than the estimated value of around 0.13 M⊙ drawn from observations, which could be explained if the radiation efficiency is low (i.e. ≪0.1). Our results indicate that repeating pTDEs could be effective tools for exploring the dynamics around SMBHs beyond our own Galaxy. 2024 Journal Article http://hdl.handle.net/20.500.11937/96139 10.1051/0004-6361/202348682 http://purl.org/au-research/grants/arc/DP200102471 https://creativecommons.org/licenses/by/4.0 fulltext
spellingShingle Liu, Z.
Ryu, T.
Goodwin, Andrew
Rau, A.
Homan, D.
Krumpe, M.
Merloni, A.
Grotova, I.
Anderson, Gemma
Malyali, A.
Miller-Jones, James
Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750
title Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750
title_full Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750
title_fullStr Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750
title_full_unstemmed Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750
title_short Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750
title_sort rapid evolution of the recurrence time in the repeating partial tidal disruption event erasst j045650.3-203750
url http://purl.org/au-research/grants/arc/DP200102471
http://hdl.handle.net/20.500.11937/96139