The Rise and Fall of ASASSN-18pg: Following a TDE from Early to Late Times
We present nearly 500 days of observations of the tidal disruption event (TDE) ASASSN-18pg, spanning from 54 days before peak light to 441 days after peak light. Our data set includes X-ray, UV, and optical photometry, optical spectroscopy, radio observations, and the first published spectropolarime...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Format: | Journal Article |
| Language: | English |
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IOP Publishing Ltd
2020
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| Subjects: | |
| Online Access: | http://purl.org/au-research/grants/arc/DP200102471 http://hdl.handle.net/20.500.11937/97230 |
| _version_ | 1848766243415261184 |
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| author | Holoien, T.W.S. Auchettl, K. Tucker, M.A. Shappee, B.J. Patel, S.G. Miller-Jones, James Mockler, B. Groenewald, D.L.N. Hinkle, J.T. Brown, J.S. Kochanek, C.S. Stanek, K.Z. Chen, P. Dong, S. Prieto, J.L. Thompson, T.A. Beaton, R.L. Connor, T. Cowperthwaite, P.S. Dahmen, L. French, K.D. Morrell, N. Buckley, D.A.H. Gromadzki, M. Roy, R. Coulter, D.A. Dimitriadis, G. Foley, R.J. Kilpatrick, C.D. Piro, A.L. Rojas-Bravo, C. Siebert, M.R. Velzen, S.V. |
| author_facet | Holoien, T.W.S. Auchettl, K. Tucker, M.A. Shappee, B.J. Patel, S.G. Miller-Jones, James Mockler, B. Groenewald, D.L.N. Hinkle, J.T. Brown, J.S. Kochanek, C.S. Stanek, K.Z. Chen, P. Dong, S. Prieto, J.L. Thompson, T.A. Beaton, R.L. Connor, T. Cowperthwaite, P.S. Dahmen, L. French, K.D. Morrell, N. Buckley, D.A.H. Gromadzki, M. Roy, R. Coulter, D.A. Dimitriadis, G. Foley, R.J. Kilpatrick, C.D. Piro, A.L. Rojas-Bravo, C. Siebert, M.R. Velzen, S.V. |
| author_sort | Holoien, T.W.S. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present nearly 500 days of observations of the tidal disruption event (TDE) ASASSN-18pg, spanning from 54 days before peak light to 441 days after peak light. Our data set includes X-ray, UV, and optical photometry, optical spectroscopy, radio observations, and the first published spectropolarimetric observations of a TDE. ASASSN-18pg was discovered on 2018 July 11 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d = 78.6 Mpc; with a peak UV magnitude of m ≃ 14, it is both one of the nearest and brightest TDEs discovered to-date. The photometric data allow us to track both the rise to peak and the long-term evolution of the TDE. ASASSN-18pg peaked at a luminosity of L ≃ 2.4 1044 erg s-1, and its late-time evolution is shallower than a flux ∝t -5/3 power-law model, similar to what has been seen in other TDEs. ASASSN-18pg exhibited Balmer lines and spectroscopic features consistent with Bowen fluorescence prior to peak, which remained detectable for roughly 225 days after peak. Analysis of the two-component Hα profile indicates that, if they are the result of reprocessing of emission from the accretion disk, the different spectroscopic lines may be coming from regions between ∼10 and ∼60 lt-days from the black hole. No X-ray emission is detected from the TDE, and there is no evidence of a jet or strong outflow detected in the radio. Our spectropolarimetric observations indicate that the projected emission region is likely not significantly aspherical, with the projected emission region having an axis ratio of ⪆0.65. |
| first_indexed | 2025-11-14T11:48:03Z |
| format | Journal Article |
| id | curtin-20.500.11937-97230 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:48:03Z |
| publishDate | 2020 |
| publisher | IOP Publishing Ltd |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-972302025-04-30T01:44:22Z The Rise and Fall of ASASSN-18pg: Following a TDE from Early to Late Times Holoien, T.W.S. Auchettl, K. Tucker, M.A. Shappee, B.J. Patel, S.G. Miller-Jones, James Mockler, B. Groenewald, D.L.N. Hinkle, J.T. Brown, J.S. Kochanek, C.S. Stanek, K.Z. Chen, P. Dong, S. Prieto, J.L. Thompson, T.A. Beaton, R.L. Connor, T. Cowperthwaite, P.S. Dahmen, L. French, K.D. Morrell, N. Buckley, D.A.H. Gromadzki, M. Roy, R. Coulter, D.A. Dimitriadis, G. Foley, R.J. Kilpatrick, C.D. Piro, A.L. Rojas-Bravo, C. Siebert, M.R. Velzen, S.V. Science & Technology Physical Sciences Astronomy & Astrophysics Black holes Accretion Galaxy accretion disks Black hole physics Supermassive black holes Tidal disruption TIDAL DISRUPTION EVENT STARS SPECTROGRAPH TELESCOPE EVOLUTION MASSES FLARE POLARIZATION CALIBRATION RESOLUTION We present nearly 500 days of observations of the tidal disruption event (TDE) ASASSN-18pg, spanning from 54 days before peak light to 441 days after peak light. Our data set includes X-ray, UV, and optical photometry, optical spectroscopy, radio observations, and the first published spectropolarimetric observations of a TDE. ASASSN-18pg was discovered on 2018 July 11 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d = 78.6 Mpc; with a peak UV magnitude of m ≃ 14, it is both one of the nearest and brightest TDEs discovered to-date. The photometric data allow us to track both the rise to peak and the long-term evolution of the TDE. ASASSN-18pg peaked at a luminosity of L ≃ 2.4 1044 erg s-1, and its late-time evolution is shallower than a flux ∝t -5/3 power-law model, similar to what has been seen in other TDEs. ASASSN-18pg exhibited Balmer lines and spectroscopic features consistent with Bowen fluorescence prior to peak, which remained detectable for roughly 225 days after peak. Analysis of the two-component Hα profile indicates that, if they are the result of reprocessing of emission from the accretion disk, the different spectroscopic lines may be coming from regions between ∼10 and ∼60 lt-days from the black hole. No X-ray emission is detected from the TDE, and there is no evidence of a jet or strong outflow detected in the radio. Our spectropolarimetric observations indicate that the projected emission region is likely not significantly aspherical, with the projected emission region having an axis ratio of ⪆0.65. 2020 Journal Article http://hdl.handle.net/20.500.11937/97230 10.3847/1538-4357/ab9f3d English http://purl.org/au-research/grants/arc/DP200102471 IOP Publishing Ltd restricted |
| spellingShingle | Science & Technology Physical Sciences Astronomy & Astrophysics Black holes Accretion Galaxy accretion disks Black hole physics Supermassive black holes Tidal disruption TIDAL DISRUPTION EVENT STARS SPECTROGRAPH TELESCOPE EVOLUTION MASSES FLARE POLARIZATION CALIBRATION RESOLUTION Holoien, T.W.S. Auchettl, K. Tucker, M.A. Shappee, B.J. Patel, S.G. Miller-Jones, James Mockler, B. Groenewald, D.L.N. Hinkle, J.T. Brown, J.S. Kochanek, C.S. Stanek, K.Z. Chen, P. Dong, S. Prieto, J.L. Thompson, T.A. Beaton, R.L. Connor, T. Cowperthwaite, P.S. Dahmen, L. French, K.D. Morrell, N. Buckley, D.A.H. Gromadzki, M. Roy, R. Coulter, D.A. Dimitriadis, G. Foley, R.J. Kilpatrick, C.D. Piro, A.L. Rojas-Bravo, C. Siebert, M.R. Velzen, S.V. The Rise and Fall of ASASSN-18pg: Following a TDE from Early to Late Times |
| title | The Rise and Fall of ASASSN-18pg: Following a TDE from Early to Late Times |
| title_full | The Rise and Fall of ASASSN-18pg: Following a TDE from Early to Late Times |
| title_fullStr | The Rise and Fall of ASASSN-18pg: Following a TDE from Early to Late Times |
| title_full_unstemmed | The Rise and Fall of ASASSN-18pg: Following a TDE from Early to Late Times |
| title_short | The Rise and Fall of ASASSN-18pg: Following a TDE from Early to Late Times |
| title_sort | rise and fall of asassn-18pg: following a tde from early to late times |
| topic | Science & Technology Physical Sciences Astronomy & Astrophysics Black holes Accretion Galaxy accretion disks Black hole physics Supermassive black holes Tidal disruption TIDAL DISRUPTION EVENT STARS SPECTROGRAPH TELESCOPE EVOLUTION MASSES FLARE POLARIZATION CALIBRATION RESOLUTION |
| url | http://purl.org/au-research/grants/arc/DP200102471 http://hdl.handle.net/20.500.11937/97230 |