Discovery and follow-up of ASASSN-23bd (AT 2023clx): The lowest redshift and luminosity optically selected tidal disruption event
We report the All-Sky Automated Survey for SuperNovae discovery of the tidal disruption event (TDE) ASASSN-23bd (AT2023clx) in NGC 3799, a LINER galaxy with no evidence of strong active galactic nucleus (AGN) activity over the past decade. With a redshift of z = 0.01107 and a peak ultraviolet (UV)/o...
| Autores: | , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/365665 |
| Acceso en línea: | http://hdl.handle.net/10261/365665 |
| Access Level: | acceso abierto |
| Palabra clave: | Accretion, accretion discs Black hole physics Transients: tidal disruption events |
| Sumario: | We report the All-Sky Automated Survey for SuperNovae discovery of the tidal disruption event (TDE) ASASSN-23bd (AT2023clx) in NGC 3799, a LINER galaxy with no evidence of strong active galactic nucleus (AGN) activity over the past decade. With a redshift of z = 0.01107 and a peak ultraviolet (UV)/optical luminosity of (5.4 ± 0.4) × 1042 erg s−1, ASASSN-23bd is the lowest-redshift and least-luminous TDE discovered to date. Spectroscopically, ASASSN-23bd shows H α and He I emission throughout its spectral time series, there are no coronal lines in its near-infrared spectrum, and the UV spectrum shows nitrogen lines without the strong carbon and magnesium lines typically seen for AGN. Fits to the rising ASAS-SN light curve show that ASASSN-23bd started to brighten on MJD 59988+1 −1, ∼9 d before discovery, with a nearly linear rise in flux, peaking in the g band on MJD 60 000+3 −3. Scaling relations and TDE light curve modelling find a black hole mass of ∼106 M, which is on the lower end of supermassive black hole masses. ASASSN-23bd is a dim X-ray source, with an upper limit of L0.3−10 keV < 1.0 × 1040 erg s−1 from stacking all Swift observations prior to MJD 60061, but with soft (∼0.1 keV) thermal emission with a luminosity of L0.3−2 keV ∼ 4 × 1039 erg s−1 in XMM-Newton observations on MJD 60095. The rapid (t < 15 d) light curve rise, low UV/optical luminosity, and a luminosity decline over 40 d of L40 ≈ −0.7 dex make ASASSN-23bd one of the dimmest TDEs to date and a member of the growing ‘Low Luminosity and Fast’ class of TDEs. |
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