Delayed and Fast-rising Radio Flares from an Optical and X-Ray-detected Tidal Disruption Event in the Center of a Dwarf Galaxy

Zhang, Fabao; Shu, Xinwen; Yang, Lei; Sun, Luming; Zhang, Zhumao; Wang, Yibo; Mou, Guobin; Zhang, Xue-Guang; Zhou, Tianyao; Peng, Fangkun

doi:10.3847/2041-8213/ad1d61

Cited by 2 publications

(2 citation statements)

References 77 publications

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“…Late-time TDE radio flares (Horesh et al 2021b;Goodwin et al 2022Goodwin et al , 2023bPerlman et al 2022;Cendes et al 2022Cendes et al , 2023Sfaradi et al 2022;Somalwar et al 2023;Christy et al 2024;Sfaradi et al 2024;Zhang et al 2024) are an intriguing part of the TDE puzzle. Some cases, notably AT2018hyz, show a very steep rise in late time.…”

Section: Discussionmentioning

confidence: 99%

“…Following the surprising discovery of late radio emission from ASASSN-15oi (Horesh et al 2021a), numerous radio flares as late as ∼1000 days after the optical discoveries (Horesh et al 2021b;Cendes et al 2022Cendes et al , 2023Goodwin et al 2022Goodwin et al , 2023bPerlman et al 2022;Sfaradi et al 2022;Somalwar et al 2023;Christy et al 2024;Zhang et al 2024;Sfaradi et al 2024) have been observed. Recently Cendes et al (2023) reported that about 40% of optical TDEs are accompanied by late-time radio flares.…”

Section: Introductionmentioning

confidence: 99%

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Late-time Radio Flares in Tidal Disruption Events

Matsumoto,

Piran

2024

ApJ

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Radio monitoring unveiled late (hundreds to a thousand days) radio flares in a significant fraction of tidal disruption events. We propose that these late-time radio flares are a natural outcome if the surrounding density profile flattens outside the Bondi radius. At the Bondi radius, the outflow is optically thin (above a few GHz) to synchrotron self-absorption. As more and more material is swept up, the radio emission rises asymptotically as ∝ t 3 until the outflow begins to decelerate. A detection of such a rise and a late-time maximum constrains the black hole mass and the mass and energy of the radio-emitting outflow. We show that this model can give reasonable fits to some observed light curves, leading to reasonable estimates of the black hole and outflow masses. We also find that the slope of the density profile within the Bondi radius determines whether an early-time (∼102 days) radio peak exists.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Late-time Radio Flares in Tidal Disruption Events

Matsumoto,

Piran

2024

ApJ

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Recurring tidal disruption events a decade apart in IRAS F01004-2237

Sun,

Jiang,

Dou

et al. 2024

A&A

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In theory, recurring tidal disruption events (TDEs) may occur when a close stellar binary encounters a supermassive black hole, if one star is captured and undergoes repeating partial TDEs, or if both stars are tidally disrupted (double TDEs). In addition, independent TDEs may be observed over decades in some special galaxies where the TDE rate is extremely high. Exploring the diversity of recurring TDEs and probing their natures with rich observational data helps us to understand these mechanisms. We report the discovery of a second optical flare that occurred in September 2021 in IRAS F01004-2237, where a first flare that occurred in 2010 had already been reported. We also present a detailed analysis of multi-band data. We aim to understand the nature of the flare and explore the possible causes of the recurring flares. We describe our analysis of the position of the flare, the multi-band light curves (LCs), the optical and ultraviolet (UV) spectra, and the X-ray LC and spectra. The position of the flare coincides with the galaxy centre with a precision of 650 pc. The flare peaks in $ days with an absolute magnitude of $ and fades in two years, roughly following $L $. It maintains a nearly constant blackbody temperature of sim 22,000 K in later stages. Its optical and UV spectra show hydrogen and helium broad emission lines with full width at half maxima of 7,000--21,000 km s$^ $ and a He II/Halpha ratio of 0.3--2.3. It shows weak X-ray emission relative to UV emission, with X-ray flares lasting for $<2-3$ weeks, during which the spectrum is soft with a power-law index of $ $. These characters are consistent with a TDE, ruling out the possibilities of a supernova or an active galactic nucleus flare. With a TDE model, we infer a peak UV luminosity of $3.3 $ erg s$^ $ and an energy budget of $4.5 $ erg. A TDE caused the flare that occurred in 2021. The two optical flares separated by $10.3 years can be interpreted as repeating partial TDEs, double TDEs, or two independent TDEs. Although no definitive conclusion can be drawn, the partial TDEs interpretation predicts a third flare around 2033, and the independent TDEs interpretation predicts a high TDE rate of $ $ yr$^ $ in F01004-2237, both of which can be tested by future observations.

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Delayed and Fast-rising Radio Flares from an Optical and X-Ray-detected Tidal Disruption Event in the Center of a Dwarf Galaxy

Cited by 2 publications

References 77 publications

Late-time Radio Flares in Tidal Disruption Events

Late-time Radio Flares in Tidal Disruption Events

Recurring tidal disruption events a decade apart in IRAS F01004-2237

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