TNS Classification Report No. 3007 [ 2018TNSCR1764....1A ]
Date Received (UTC): 2018-11-13 17:55:28 Sender: Dr. Iair Arcavi
Group: None
Iair Arcavi report/s a classification of object: AT 2018hyz
Type: TDERedshift: 0.04573
Remarks: The spectrum shows broad Balmer emission lines on top of a blue continuum, consistent with both a young Type II supernova or a tidal disruption event (e.g. Arcavi et al. 2014, ApJ, 793, 38; Holoien et al. 2014, MNRAS, 445, 3263), as noted by Dong et al. 2018 (ATel 12198). Superfit (Howell et al. 2005, ApJ, 634, 1190) finds better a better fit to the TDE PTF09djl (Arcavi et al. 2014, ApJ, 793, 38) than to young Type II supernovae (though the broad He II emission feature seen in many TDEs is still absent here). Also noted by Dong et al. 2018 (ATel 12198) is that an archival spectrum of the host galaxy from SDSS (from which the redshift in this report is taken, retrieved via DR14) displays strong narrow Balmer absorption features consistent with an E+A / Quiescent Balmer Strong galaxy - an environment strongly preferred by TDEs (Arcavi et al. 2014, ApJ 793, 38; French, Arcavi & Zabludoff, 2016, ApJL, 818, 21). The coordinates reported for this object in Brimacombe et al. (ATel 12194) are more consistent with the center of the host galaxy compared to the coordinates initially reported to the TNS, further strengthening the case for a TDE classification.
The following Classification spectrum was provided:
Obsdate: 2018-11-12 13:16:53
Instrument: FLOYDS-N
Telescope: Faulkes Telescope North
Details of the object and its spectra can be viewed here: https://www.wis-tns.org/object/2018hyz
Date Received (UTC): 2018-11-13 17:55:28 Sender: Dr. Iair Arcavi
Group: None
Iair Arcavi report/s a classification of object: AT 2018hyz
Type: TDERedshift: 0.04573
Remarks: The spectrum shows broad Balmer emission lines on top of a blue continuum, consistent with both a young Type II supernova or a tidal disruption event (e.g. Arcavi et al. 2014, ApJ, 793, 38; Holoien et al. 2014, MNRAS, 445, 3263), as noted by Dong et al. 2018 (ATel 12198). Superfit (Howell et al. 2005, ApJ, 634, 1190) finds better a better fit to the TDE PTF09djl (Arcavi et al. 2014, ApJ, 793, 38) than to young Type II supernovae (though the broad He II emission feature seen in many TDEs is still absent here). Also noted by Dong et al. 2018 (ATel 12198) is that an archival spectrum of the host galaxy from SDSS (from which the redshift in this report is taken, retrieved via DR14) displays strong narrow Balmer absorption features consistent with an E+A / Quiescent Balmer Strong galaxy - an environment strongly preferred by TDEs (Arcavi et al. 2014, ApJ 793, 38; French, Arcavi & Zabludoff, 2016, ApJL, 818, 21). The coordinates reported for this object in Brimacombe et al. (ATel 12194) are more consistent with the center of the host galaxy compared to the coordinates initially reported to the TNS, further strengthening the case for a TDE classification.
The following Classification spectrum was provided:
Obsdate: 2018-11-12 13:16:53
Instrument: FLOYDS-N
Telescope: Faulkes Telescope North
Details of the object and its spectra can be viewed here: https://www.wis-tns.org/object/2018hyz