ZTF22aabjpxh/AT2022cva (GRB 220219B): continued optical observations, possible photometric evidence of SN
Abstract
We are continuing observations of ZTF22aabjpxh/AT2022cva discovered by ZTF (Ho et al., GCN 31619) with AZT-33IK telescope of Mondy observatory, AS-32 telescope of Abastumani observatory, and Zeiss-1000 telescope of SAO RAS between 2022-02-24 and 2022-03-09. ZTF22aabjpxh/AT2022cva was observed in optic (Kim et al., GCN 31628; Hu et al., GCN 31639; Belkin et al., GCNs 31643, 31683) and in X-ray by NICER (Pasham et al., GCN 31635) and XRT/Swift (Beardmore et al., GCN 31644). ZTF22aabjpxh/AT2022cva is considered an afterglow of GRB 220219B (Ho et al., GCN 31619; Svinkin et al., GCN 31624; Tsvetkova et al., GCN 31646; Belkin et al., GCN 31683). We clearly detect the SDSS galaxy at z=0.293 (Fremling et al., GCN 31629). Due to non-optimal seeing we could not discriminate the afterglow from the galaxy. We use aperture photometry of a source (afterglow + host galaxy). Based on our preliminary photometry we plot a light curve of the source, see an upper panel of the Figure in http://grb.rssi.ru/GRB220219B/GRB220219B_AT2022cva_LC.png To estimate power law index of the afterglow we fit our photometric data by a single power law + constant host galaxy flux between start of our observations and up to 13.4 days after GRB 220219B trigger. The host galaxy fit is R = 19.68+/-0.05 and PL index alpha = -1.75+/-0.4 (Belkin et al., GCN 31683). The light curve of the afterglow after subtraction of a flux of the host is presented at the bottom panel of the Figure in http://grb.rssi.ru/GRB220219B/GRB220219B_AT2022cva_LC.png Starting on ~15.5 days the light curve is rising above afterglow approximation by the single power law and we consider it as a possible evidence of rising supernova. We urge further spectroscopic and multicolour observations to confirm for SN associated with GRB 220219B.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- March 2022
- Bibcode:
- 2022GCN.31736....1B