AstroNote 2021-10

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DRAFT
2021-01-07 22:40:23
Type: Object/s-Discovery/Classification
ZTF discovery of enhanced optical activity associated with the quadruply imaged quasar 2M J1134-2103
Authors: A. Munoz-Arancibia (MAS), F.E. Bauer (UC/MAS), T. Anguita (UNAB/MAS), F. Forster (CMM/MAS), P. Sanchez-Saez (MAS/UC/UAI), L. Hernandez-Garcia (MAS), on behalf of the ALeRCE broker
Source Group: ZTF
Keywords: Transient
Abstract:
We report the discovery of ZTF21aabgpub / AT 2021ia, a transient associated with the gravitationally lensed system 2M J1134-2103 (Lucey et al. 2018), reported by the ALeRCE broker (TNS #95604) using the ZTF public alert stream. The object is detected at 18.32 mag on a ZTF r-band difference image obtained on Jan 4th, 2021 at 12:55 UT, with two subsequent detections at 18.48 mag (g-band) and 18.20 mag (r-band) on Jan 5th, 2021 and Jan 7th, 2021 respectively. Another ZTF transient, ZTF20aaehksw, is found to be located within ~0.66 arcsec of ZTF21aabgpub, with two detections extending back to Jan 3rd, 2020 and Jan 6th, 2020, and eight further detections between Dec 21st, 2020 to Jan 7th, 2021. Both ZTF21aabgpub and ZTF20aaehksw lie towards image A of the lensed system. All quoted magnitudes are difference magnitudes. We encourage additional follow-up observations of this transient.

We report the discovery of ZTF21aabgpub / AT 2021ia, a transient reported by the ALeRCE broker (TNS #95604) using the ZTF public alert stream. The object is detected on a ZTF r-band difference image obtained on Jan 4th, 2021 at 12:55 UT with 18.32+-0.20 mag, with no previously reported non-detections in the ZTF public stream bands. Since then, there were two subsequent detections at 18.48 mag (g-band) and 18.20 mag (r-band) on Jan 5th, 2021 and Jan 7th, 2021 respectively. Its ZTF light curve can be explored in https://alerce.online/object/ZTF21aabgpub. ZTF21aabgpub is located towards 2M J1134-2103, a quadruply imaged quasar (Lucey et al. 2018).

A search for previous ZTF detections in the line of sight of the gravitationally lensed system revealed another transient, ZTF20aaehksw, detected on a ZTF r-band difference image obtained on Jan 3rd, 2020 at 11:31 UT with 19.05+-0.24 mag. This object shows a second detection at 19.01 mag on Jan 6th, 2020, and a third detection at 18.23 mag on Dec 21st, 2020 (350 days later), both in the r-band. Since then it has two r-band and three g-band subsequent detections, the last one on Jan 7th, 2021. Its ZTF light curve can be explored in https://alerce.online/object/ZTF20aaehksw.

The angular separation between the average coordinates of ZTF21aabgpub and ZTF20aaehksw is ~0.66 arcsec. Both objects lie towards the A quasar image, but show faint elongation extending toward images B and C of the lensed system (image naming scheme from Lucey et al. 2018). All quoted magnitudes are difference magnitudes. We encourage additional follow-up observations of this transient.

Show current TNS values
CatalogNameReported RAReported DECReported Obj-TypeReported RedshiftHost NameHost RedshiftRemarksTNS RATNS DECTNS Obj-TypeTNS Redshift
TNS2021ia11:34:40.607-21:03:22.6811:34:40.607-21:03:22.68Other