Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event

Physics

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https://doi.org/10.3847/1538-4357/ab24de
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Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event. / Hung, T.; Cenko, S. B.; Roth, Nathaniel et al.
In: The Astrophysical Journal, Vol. 879, No. 2, 119, 15.07.2019.

Research output: Contribution to Journal/Magazine › Journal article › peer-review

Harvard

Hung, T, Cenko, SB, Roth, N, Gezari, S, Veilleux, S, van Velzen, S, Gaskell, CM, Foley, RJ, Blagorodnova, N, Yan, L, Graham, MJ, Brown, JS, Siebert, MR, Frederick, S, Ward, C, Gatkine, P, Gal-Yam, A, Yang, Y, Schulze, S, Dimitriadis, G, Kupfer, T, Shupe, DL, Rusholme, B, Masci, FJ, Riddle, R, Soumagnac, MT, van Roestel, J & Dekany, R 2019, 'Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event', The Astrophysical Journal, vol. 879, no. 2, 119. https://doi.org/10.3847/1538-4357/ab24de

APA

Hung, T., Cenko, S. B., Roth, N., Gezari, S., Veilleux, S., van Velzen, S., Gaskell, C. M., Foley, R. J., Blagorodnova, N., Yan, L., Graham, M. J., Brown, J. S., Siebert, M. R., Frederick, S., Ward, C., Gatkine, P., Gal-Yam, A., Yang, Y., Schulze, S., ... Dekany, R. (2019). Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event. The Astrophysical Journal, 879(2), Article 119. https://doi.org/10.3847/1538-4357/ab24de

Vancouver

Hung T, Cenko SB, Roth N, Gezari S, Veilleux S, van Velzen S et al. Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event. The Astrophysical Journal. 2019 Jul 15;879(2):119. doi: 10.3847/1538-4357/ab24de

Author

Hung, T. ; Cenko, S. B. ; Roth, Nathaniel et al. / Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event. In: The Astrophysical Journal. 2019 ; Vol. 879, No. 2.

Bibtex

@article{8f8d05c56beb4590b5cc27c174950a20,

title = "Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event",

abstract = "We report the discovery of nonstellar hydrogen Balmer and metastable helium absorption lines accompanying a transient, high-velocity (0.05c) broad absorption line (BAL) system in the optical spectra of the tidal disruption event (TDE) AT2018zr (z =0.071). In the Hubble Space Telescope UV spectra, absorption of high- and low-ionization lines is also present at this velocity, making AT2018zr resemble a low-ionization BALQSO. We conclude that these transient absorption features are more likely to arise in fast outflows produced by the TDE than absorbed by the unbound debris. In accordance with the outflow picture, we are able to reproduce the flat-topped Hα emission in a spherically expanding medium without invoking the typical prescription of an elliptical disk. We also report the appearance of narrow (∼1000 kms -1) N iii λ4640, He ii λ4686, Hα, and Hβ emission in the late-time optical spectra of AT2018zr, which may be a result of UV continuum hardening at late times, as observed by Swift. Including AT2018zr, we find a high association rate (three out of four) of BALs in the UV spectra of TDEs. This suggests that outflows may be ubiquitous among TDEs and less sensitive to viewing angle effects compared to QSO outflows.",

author = "T. Hung and Cenko, {S. B.} and Nathaniel Roth and S. Gezari and S. Veilleux and {van Velzen}, Sjoert and Gaskell, {C. Martin} and Foley, {Ryan J.} and N. Blagorodnova and Lin Yan and Graham, {M. J.} and Brown, {J. S.} and Siebert, {M. R.} and Sara Frederick and Charlotte Ward and Pradip Gatkine and Avishay Gal-Yam and Yi Yang and Steve Schulze and G. Dimitriadis and Thomas Kupfer and Shupe, {David L.} and Ben Rusholme and Masci, {Frank J.} and Reed Riddle and Soumagnac, {Maayane T.} and {van Roestel}, J. and Richard Dekany",

year = "2019",

month = jul,

day = "15",

doi = "10.3847/1538-4357/ab24de",

language = "English",

volume = "879",

journal = "The Astrophysical Journal",

issn = "0004-637X",

publisher = "Institute of Physics Publishing",

number = "2",

}

RIS

TY - JOUR

T1 - Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event

AU - Hung, T.

AU - Cenko, S. B.

AU - Roth, Nathaniel

AU - Gezari, S.

AU - Veilleux, S.

AU - van Velzen, Sjoert

AU - Gaskell, C. Martin

AU - Foley, Ryan J.

AU - Blagorodnova, N.

AU - Yan, Lin

AU - Graham, M. J.

AU - Brown, J. S.

AU - Siebert, M. R.

AU - Frederick, Sara

AU - Ward, Charlotte

AU - Gatkine, Pradip

AU - Gal-Yam, Avishay

AU - Yang, Yi

AU - Schulze, Steve

AU - Dimitriadis, G.

AU - Kupfer, Thomas

AU - Shupe, David L.

AU - Rusholme, Ben

AU - Masci, Frank J.

AU - Riddle, Reed

AU - Soumagnac, Maayane T.

AU - van Roestel, J.

AU - Dekany, Richard

PY - 2019/7/15

Y1 - 2019/7/15

N2 - We report the discovery of nonstellar hydrogen Balmer and metastable helium absorption lines accompanying a transient, high-velocity (0.05c) broad absorption line (BAL) system in the optical spectra of the tidal disruption event (TDE) AT2018zr (z =0.071). In the Hubble Space Telescope UV spectra, absorption of high- and low-ionization lines is also present at this velocity, making AT2018zr resemble a low-ionization BALQSO. We conclude that these transient absorption features are more likely to arise in fast outflows produced by the TDE than absorbed by the unbound debris. In accordance with the outflow picture, we are able to reproduce the flat-topped Hα emission in a spherically expanding medium without invoking the typical prescription of an elliptical disk. We also report the appearance of narrow (∼1000 kms -1) N iii λ4640, He ii λ4686, Hα, and Hβ emission in the late-time optical spectra of AT2018zr, which may be a result of UV continuum hardening at late times, as observed by Swift. Including AT2018zr, we find a high association rate (three out of four) of BALs in the UV spectra of TDEs. This suggests that outflows may be ubiquitous among TDEs and less sensitive to viewing angle effects compared to QSO outflows.

AB - We report the discovery of nonstellar hydrogen Balmer and metastable helium absorption lines accompanying a transient, high-velocity (0.05c) broad absorption line (BAL) system in the optical spectra of the tidal disruption event (TDE) AT2018zr (z =0.071). In the Hubble Space Telescope UV spectra, absorption of high- and low-ionization lines is also present at this velocity, making AT2018zr resemble a low-ionization BALQSO. We conclude that these transient absorption features are more likely to arise in fast outflows produced by the TDE than absorbed by the unbound debris. In accordance with the outflow picture, we are able to reproduce the flat-topped Hα emission in a spherically expanding medium without invoking the typical prescription of an elliptical disk. We also report the appearance of narrow (∼1000 kms -1) N iii λ4640, He ii λ4686, Hα, and Hβ emission in the late-time optical spectra of AT2018zr, which may be a result of UV continuum hardening at late times, as observed by Swift. Including AT2018zr, we find a high association rate (three out of four) of BALs in the UV spectra of TDEs. This suggests that outflows may be ubiquitous among TDEs and less sensitive to viewing angle effects compared to QSO outflows.

UR - https://publons.com/wos-op/publon/28547414/

U2 - 10.3847/1538-4357/ab24de

DO - 10.3847/1538-4357/ab24de

M3 - Journal article

VL - 879

JO - The Astrophysical Journal

JF - The Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 119

ER -

Research

Text available via DOI: