AT 2018dyk
RA/DEC ()
15:33:08.015 +44:32:08.20
233.2833955 +44.5356122
Type
TDE
Redshift
0.037
Source Group
ZTF
Discovery Date
2018-05-31 07:26:24
TNS AT
Y
Public
Y
Discovery Mag
19.41
Filter
g-ZTF
Discoverer/s
C. Fremling (Caltech) on behalf of the Zwicky Transient Facility (ZTF) collaboration

Spectra

 AT_2018dyk - 2018-08-12 07:00:56 FTN / FLOYDS-N (None)z=
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   Binning factor: (rounded to nearest integer >1)
Mouse hovers at WL: 0 (rest),0 (observed)
Spectra
SelectIDObs-date (UT)Tel / InstExp-TimeObserver/sReducer/sGroupSpectrum ascii fileSpectrum fits fileSpec. TypeAssoc. GroupsEnd prop. periodRemarks
25222018-08-12 07:00:56FTN / FLOYDS-N3600RoboticJ. BurkeNone tns_2018dyk_2018-08-12_07-00-56_FTN_FLOYDS-N.ascii tns_2018dyk_2018-08-12_07-00-56_FTN_FLOYDS-N.fitsObject
Light Curves
FilterTel / InstObs-date rangePhotometry
g-ZTFP48_ZTF-Cam2018-05-28 09:57:36 - 2018-05-31 07:26:242
Photometry
IDObs-dateMag. / FluxErrLim. Mag./FluxUnitsFilterTel / InstExp-timeObserver/sRemarks
320632018-05-31 07:26:2419.41ABMagg-ZTFP48_ZTF-Cam30ZTF
320622018-05-28 09:57:3619.04ABMagg-ZTFP48_ZTF-Cam30ZTF[Last non detection]
r-ZTFP48_ZTF-Cam2018-07-15 04:17:45 - 2018-07-15 04:17:451
Photometry
IDObs-dateMag. / FluxErrLim. Mag./FluxUnitsFilterTel / InstExp-timeObserver/sRemarks
320642018-07-15 04:17:4519.06ABMagr-ZTFP48_ZTF-Cam30ZTF
AT Reportings
IDTime received (UT)SenderReporter/s (Discoverer/s)GroupRADECDiscovery date (UT)Discovery Mag.FilterRelated filesAT TypeInternal nameAssoc. GroupsEnd prop. periodRemarks
206772018-07-15 20:46:55ZTF_Bot1C. Fremling (Caltech) on behalf of the Zwicky Transient Facility (ZTF) collaborationZTF15:33:08.015+44:32:08.202018-05-31 07:26:2419.41g-ZTFPSNZTF18aajupntZTF
Classification Reportings
IDTime received (UT)SenderClassifier/sGroupClassificationRedshiftRelated filesAssoc. GroupsEnd prop. periodRemarks
25152018-08-15 01:01:20iairI Arcavi J Burke D Hiramatsu C McCully A Howell G Hosseinzadeh (LCO) D French (Carnegie) A Zabludoff (Arizona) S Valenti (Davis)NoneTDE0.037We obtained a spectrum of the nuclear transient AT 2018dyk/ZTF18aajupnt on 2018 August 12.3 UT with the robotic FLOYDS instrument mounted on the Las Cumbres Observatory 2-meter telescope on Haleakala, Hawai'i, under the "Transients in Galaxy Centers" program (PI: Arcavi). Using Superfit (Howell et al. 2005, ApJ, 634, 1190), we find a reasonable fit to the tidal disruption event (TDE) ASASSN-14ae (Holoien et al. 2014, MNRAS, 445, 3263; Arcavi et al. 2014, ApJ, 793, 38) at the redshift of the host galaxy (z=0.037; SDSS). The spectrum displays possible broad H-alpha, H-beta and He II emission lines, similar to those seen in other TDEs. Unlike other TDEs, however, it displays narrow H-beta and He II emission lines not seen in the SDSS host spectrum, stronger narrow H-alpha compared to the SDSS host spectrum, and it does not display a blue continuum. The ZTF light curve retrieved from the ZTF public alert stream via MARS (https://mars.lco.global/7014426/) peaks at an apparent magnitude of about 18.6, which at the deduced redshift corresponds to an absolute magnitude of -17.4, several magnitudes fainter than most TDEs but similar to the TDE iPTF16fnl (Blagorodnova et al. 2017, ApJ, 844, 46). The SDSS spectrum of the host galaxy shows weak H-alpha emission indicative of only weak current star formation, and does not show strong Balmer absorption which would be indicative of a recent strong starburst. The recent star formation history of the host galaxy appears similar to that of the TDE PTF09ge (Arcavi et al. 2014, ApJ, 793, 38), which formed less than 1% of it's current stellar mass in the last Gyr (French et al. 2016, ApJL, 818, 21; French et al. 2017, ApJ, 835, 176).