Revisiting the Rates and Demographics of Tidal Disruption Events: Effects of the Disk Formation Efficiency

Wong, Thomas Hong Tsun; Pfister, Hugo; Dai, Lixin

doi:10.3847/2041-8213/ac5823

Cited by 10 publications

(7 citation statements)

References 45 publications

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“…In this section, we compare our model predictions to the observed properties of TDEs. We start from the TDE catalog in Gezari (2021), which also lists the observed blackbody luminosities and temperatures, and then only include TDEs that have their masses estimated from the M-σ relation as in Wong et al (2022). This gives us 7 X-ray selected TDEs (Table D1) and 16 optically selected TDEs (Table D2).…”

Section: Comparison With Observations: Blackbody Luminositymentioning

confidence: 99%

Dynamical Unification of Tidal Disruption Events

Thomsen

Kwan

Dai

et al. 2022

ApJL

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The ∼100 tidal disruption events (TDEs) observed so far exhibit a wide range of emission properties both at peak and over their lifetimes. Some TDEs radiate predominantly at X-ray energies, while others radiate chiefly at UV and optical wavelengths. While the peak luminosities across TDEs show distinct properties, the evolutionary behavior can also vary between TDEs with similar peak emission properties. In particular, for optical TDEs, while their UV and optical emissions decline somewhat following the fallback pattern, some events can greatly rebrighten in X-rays at late time. In this Letter, we conduct three-dimensional general relativistic radiation magnetohydrodynamics simulations of TDE accretion disks at varying accretion rates in the regime of super-Eddington accretion. We make use of Monte Carlo radiative transfer simulations to calculate the reprocessed spectra at various inclinations and at different evolutionary stages. We confirm the unified model proposed by Dai et al., which predicts that the observed emission largely depends on the viewing angle of the observer with respect to the disk orientation. Furthermore, we find that disks with higher accretion rates have elevated wind and disk densities, which increases the reprocessing of the high-energy radiation and thus generally augments the optical-to-X-ray flux ratio along a particular viewing angle. This implies that at later times, as the accretion level declines, we expect that more X-rays will leak out along intermediate viewing angles. Such dynamical model for TDEs can provide a natural explanation for the diversity in the emission properties observed in TDEs at peak and along their temporal evolution.

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Section: Comparison With Observations: Blackbody Luminositymentioning

confidence: 99%

Dynamical Unification of Tidal Disruption Events

Thomsen

Kwan

Dai

et al. 2022

ApJL

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this section, we compare our model predictions to the observed properties of TDEs. We start from the TDE catalog in Gezari (2021) which also lists the observed blackbody luminosities and temperatures, and then only include TDEs which have their masses estimated from the M − σ relation as in Wong et al (2022). This gives us 7 X-ray-selected TDEs (Table C.1) and 16 optically-selected TDEs (Table C.2).…”

Section: Comparison With Observations: Blackbody Luminosity Effective...mentioning

confidence: 99%

Dynamical Unification of Tidal Disruption Events

Thomsen,

Kwan,

Dai

et al. 2022

Preprint

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About a hundred tidal disruption events (TDEs) have been observed and they exhibit a wide range of emission properties both at peak and over their lifetimes. Some TDEs peak predominantly at X-ray energies while others radiate chiefly at UV and optical wavelengths. While the peak luminosities across TDEs show distinct properties, the evolutionary behavior can also vary between TDEs with similar peak emission properties. At late time, some optical TDEs rebrighten in X-rays, while others maintain strong UV/optical emission components. In this Letter, we conduct three-dimensional general relativistic radiation magnetohydrodynamics simulations of TDE accretion disks at varying accretion rates ranging from a few to a few tens of the Eddington accretion rate. We make use of Monte Carlo radiative transfer simulations to calculate the reprocessed spectra at various inclinations and at different evolutionary stages. We confirm the unified model proposed by Dai et al. (2018), which predicts that the observed emission largely depends on the viewing angle of the observer with respect to the disk orientation (X-ray strong when viewed face-on and UV/optically strong when viewed disk-on). What is more, we find that disks with higher accretion rates have elevated wind and disk densities, which increases the reprocessing of the high-energy radiation and thus generally augments the optical-to-X-ray flux ratio along a particular viewing angle. This implies that at later times, as the accretion level declines, we expect the funnel to effectively open up and allow more X-rays to leak out along intermediate viewing angles. Such dynamical model for TDEs can provide a natural explanation for the diversity in the emission properties observed in TDEs at peak and along their temporal evolution.

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“…Moreover, Charlton et al (2019) have shown the total stellar mass of SDSS J0159 is about 4.7 × 10 10 M ⊙ , indicating the central BH mass about 6 × 10 6 M ⊙ (the accepted value in Wong et al (2022)) in SDSS J0159 through the correlation between central BH mass and total stellar mass as discussed in Haring & Rix (2004); Sani et al (2011); Kormendy & Ho (2013); Reines & Volonteri (2015), roughly consistent with the BH mass estimated by the M-sigma relation reported in our previous paper Zhang et al (2019). Therefore, besides the virial BH mass through virialization assumption to BLRs clouds and the BH mass through the M-sigma relation and through the total stellar mass, BH mass of SDSS J0159 determined through one another independent method will be very interesting and meaningful.…”

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confidence: 96%

“…Among the reported TDE candidates, SDSS J0159 is an interesting object, because its central virial BH mass reported as ∼ 10 8 M ⊙ in LaMassa et al (2015); Merloni et al (2015) through the virialization assumptions (Peterson et al 2004;Greene & Ho 2005;Vestergaard & Peterson 2006;Kelly & Bechtold 2007;Rafiee & Hall 2011;Shen et al 2011;Mejia-Restrepo et al 2022) applied to BLRs (broad emission line regions) clouds, the largest BH mass among the reported BH masses of TDE candidates in Wevers et al (2017); Mockler et al (2019); Zhou et al (2021); Wong et al (2022). However, variations of accretion flows have apparent effects on dynamical structures of BLRs, if the BLRs clouds are tightly related to TDEs, such as the more detailed abnormal variabilities of broad emission lines in the TDE candidate ASASSN-14li in Holoien et al (2016): strong emissions leading to wider line widths of broad H which are against the expected results by the Virialization assumptions to BLRs clouds.…”

mentioning

confidence: 99%

Central BH mass of tidal disruption event candidate SDSS J0159 through long-term optical variabilities

Zhang¹

2023

Preprint

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In this manuscript, central BH mass is determined in the tidal disruption event (TDE) candidate SDSS J0159, through the nine years long variabilities, in order to check whether the virial BH mass is consistent with the mass estimated by another independent methods. First, host galaxy spectroscopic features are described by 350 simple stellar templates, to confirm the total stellar mass about 7 × 10 10 M ⊙ in SDSS J0159, indicating the virial BH mass about two magnitudes larger than the BH mass estimated by the total stellar mass. Second, based on an efficient method and fitting procedure, through theoretical TDE model applied to describe the SDSS -band light curves of SDSS J0159, central BH mass can be determined as ∼ 4.5 +1.3 −1.1 × 10 6 M ⊙ , well consistent with the M-sigma relation expected BH mass and the total stellar mass expected BH mass. Third, the theoretical TDE model with parameter of central BH mass limited to be higher than 10 8 M ⊙ can not lead to reasonable descriptions to the light curves of SDSS J0159, indicating central BH mass higher than 10 8 M ⊙ is not preferred in SDSS J0159. Therefore, the TDE model determined central BH mass of SDSS J0159 are about two magnitudes lower than the virial BH mass, to support central BLRs including accreting debris contributions from central TDE, and provide interesting clues to reconfirm that outliers in the space of virial BH mass versus stellar velocity dispersion should be better candidates of TDE.

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Revisiting the Rates and Demographics of Tidal Disruption Events: Effects of the Disk Formation Efficiency

Cited by 10 publications

References 45 publications

Dynamical Unification of Tidal Disruption Events

Dynamical Unification of Tidal Disruption Events

Dynamical Unification of Tidal Disruption Events

Central BH mass of tidal disruption event candidate SDSS J0159 through long-term optical variabilities

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