Difference: Papers (1 vs. 4)

A New Class of Changing Look LINERs

Lead(s): Sara Frederick (UMD)

Objects: ZTF18aajupnt (aka ZTF-TyrionLannister, AT2018dyk), ZTF18aasuray (AT2018cdp), ZTF18aahiqfi (AT2018aij), ZTF18aaidlyq (AT2018ivp), ZTF18aasszwr (AT2018lnh), ZTF18aaabltn (AT2018gkr)

Observations: Tyrion: HST STIS spectroscopy, Swift XRT/UVOT, XMM-Newton, Spitzer photometry; DCT/Keck/P200/P60 spectroscopy

Brief Description: We report the discovery of six AGN caught ``turning on" during the ZTF survey. We found via follow-up spectroscopy that they had transformed from LINERs into broad-line AGN, reminiscent of iPTF16bco. In one case, follow-up UV and optical spectra revealed the transformation into a narrow-line Seyfert 1 with strong coronal lines, and Swift monitoring revealed bright UV emission that tracked the optical flare, accompanied by a luminous soft X-ray flare that peaked ~60 days later. Archival light curves of the entire sample from CRTS, ATLAS, and ASAS-SN constrain the onset of the optical nuclear flaring from a prolonged quiescent state. We present the systematic selection and follow-up of this unique class of transients related to physical processes associated with the LINER accretion state, and compare their properties to previously reported changing-look Seyferts.

Status: Submitted to ApJ on April 23, 2019, posted to arxiv

UV and optical spectroscopic evolution of AT2018zr

Leads: Tiara Hung (UCSC)

Objects: ZTF18aabtxvd (aka ZTF-NedStark, AT2018zr)

Observations: HST STIS spectroscopy, DCT/Keck spectroscopy

Brief Description:

Status: in prep

The first tidal disruption flare in ZTF: from photometric selection to multi-wavelength characterization

ZTFbh Papers in Preparation

The first stellar tidal disruption flare in ZTF: from photometric selection to multi-wavelength characterization

Leads: Sjoert van Velzen (UMd)

Objects: ZTF18aabtxvd (aka ZTF-NedStark, AT2018zr)

Observations: ZTF light curve, Swift UVOT photometry, XMM X-ray imaging, VLA radio imaging

Brief Description: We report the independent discovery of the transient source AT2018zr during commission observations of the Zwicky Transient Facility (ZTF), the first tidal disruption event (TDE) found in this survey. The ZTF light curve of the TDE samples the rise-to-peak exceptionally well, with 50 days of g and r-band detections before the time of maximum light. We also present our multi-wavelength followup observations that were triggered by the discovery of this flare: the detection of a weak X-ray source and a stringent upper limit to the radio emission.

Status: submitted to Pub Board on August 28, 2018

-- SuviGezari - 30 Aug 2018