{
  "bibcode": "2021GCN.30419....1R",
  "body": "Simeon Reusch, Jannis Necker, Robert Stein (DESY), Anna Franckowiak (DESY/Ruhr-University Bochum), Sven Weimann (Ruhr-University Bochum), Sjoert van Velzen (Leiden University), Marek Kowalski (DESY), Mansi Kasliwal and Matthew Graham (Caltech) report:\n\nWe observed ZTF candidate AT2021osi (Necker et al, GCN 30349), a possible counterpart to high-energy neutrino IceCube-210629A (Santander et. al, GCN 30342), with the Gemini GMOS-N spectrograph on 2 July 2021. Using the R400 grating (1 arcsec slit), we obtained 2 x 750s observations under our ToO program GN-2021A-Q-116 (PI: Kasliwal). These were reduced and flux-calibrated with PypeIt (Prochaska et al. 2020).\n\nThe spectrum of AT2021osi shows AGN-like features, namely prominent and broad Balmer lines (alpha, beta and gamma). Based on these lines, we also infer a redshift z=0.194.\n\nWe thank the GMOS-N observing staff for quickly scheduling and executing our observations, in particular Atsuko Nitta.",
  "circularId": 30419,
  "createdOn": 1625760264000,
  "email": "simeon.reusch@desy.de",
  "subject": "IceCube-210629A - Spectroscopic observation of AT2021osi",
  "submitter": "Simeon Reusch at DESY  <simeon.reusch@desy.de>",
  "eventId": "IceCube-210629A"
}