LIGO/Virgo S200213t: Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
Abstract
We report Swift/UVOT and XRT follow-up observations of ZTF20aamvmzj (AT2020cja; Kasliwal et al., GCN Circ. 27051) found by Zwicky Transient Facility during the search for the EM counterpart of the LVC event S200213t (LIGO/VIRGO Collaboration GCN Circ. 27042). This object was also observed by Lulin (Li et al., GCN Circ. 27082) and spectroscopically by DBSP (Ho et al., GCN Circ. 27074). Swift/UVOT and XRT observations began 6.7 days after the LIGO/VIRGO trigger (LIGO/VIRGO Collaboration GCN Circ. 27042). We detect ZTF20aamvmzj in the u and UV filters only. In the following we give preliminary magnitudes using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373): Filter T_start(s) T_stop(s) Exp(s) Mag v 577293 588978 228 >19.2 b 576882 588576 236 >19.92 u 576797 588492 236 19.05 +/- 0.27 w1 576633 588408 472 19.46 +/- 0.30 m2 577377 583756 753 19.82 +/- 0.29 w2 576967 588902 944 19.64 +/- 0.23 The magnitudes in the table are not corrected for the Galactic extinction due to the significant reddening of E(B-V) = 0.23 in the direction of the burst (Schlegel et al. 1998). In XRT, no source was found at the location of ZTF20aamvmzj, down to a 3-sigma upper limit of 3.1e-3 count s^-1 in 3 ks of exposure. Assuming a power-law spectrum with NH=3x10^20 cm^-2, and photon index (Gamma)=1.7, this equates to a upper limit of F < 1.2x10^-13 erg cm^-2 s^-1 on the 0.3-10 keV observed flux. This circular is an official product of the Swift team.
- Publication:
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GRB Coordinates Network
- Pub Date:
- February 2020
- Bibcode:
- 2020GCN.27153....1O