TITLE: GCN CIRCULAR NUMBER: 25540 SUBJECT: LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx DATE: 19/08/29 08:01:11 GMT FROM: Douglas Tucker at Fermilab LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx Matt Wiesner (Benedictine U), Melissa Butner (ETSU), Douglas Tucker (Fermilab), Ósmar Rodríguez (UNAB), Nicolás Meza-Retamal (ESO Chile), Jonathan Quirola (PUC), Felipe Olivares (INCT/UDA), Regis Cartier (NOAO/CTIO), Sean Points (NOAO/CTIO), Sahar Allam (Fermilab), Marcelle Soares-Santos (Brandeis U), Clara Martinez-Vazquez (NOAO/CTIO), Alyssa Garcia (Brandeis U), Ken Herner (Fermilab), James Annis (Fermilab), Antonella Palmese (Fermilab), Nora Sherman (Fermilab and Brandeis U), Robert Morgan (U of Wisconsin-Madison), Tristan Bachmann (U Chicago), Tamara Davis (U Queensland), Ana Carolina de Souza Feliciano (ON) On behalf of the DESGW team*: We report SOAR Goodman spectroscopy of AT2019ntr and AT2019omx, possible counterparts to the black hole-neutron star merger S190814bv reported by the GROWTH team (GCN Circular No. GCN 25393) and our team (GCN Circular No. GCN 25486) based on data obtained by the DESGW team using the CTIO Blanco/DECam instrument. We obtained a 45 min exposure of 2019ntr and a 4 min exposure of the galaxy associated with 2019omx using the Goodman instrument on the 4.1m SOAR telescope at Cerro Pachón. The analysis of these spectra allow us to conclude that 2019ntr is unrelated to the merger: 2019ntr appears to be consistent with a Type II-L supernova at a redshift of about 0.2 (based on running the observed spectrum through the astrodash SN classification software package). We also report a redshift for the host galaxy of 2019omx of 0.275 (based on assuming a strong emission line at 8370 Angstroms is H-alpha). The SOAR followup program is a partnership between the US (PIs: Kilpatrick & Tucker), Chilean (PI: Olivares), and Brazilian (PI: Makler) community. The candidates were identified in data taken by the DECam Search & Discovery Program for Optical Signatures of Gravitational Wave Events (DESGW, PI: Soares-Santos), which is carried out by the Dark Energy Survey (DES) collaboration in partnership with wide ranging groups in the community. DESGW uses data obtained with the Dark Energy Camera (DECam), which was constructed by the DES collaboration with support from the Department of Energy and member institutions, and utilizes data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes do Brasil (MCTIC/LNA), the U.S. National Science Foundation's National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). *The DESGW Collaboration: Sahar Allam (Fermilab), James Annis (Fermilab), Iair Arcavi (Tel Aviv U), Tristan Bachmann (U Chicago), Paulo Barchi (INPE & Brandeis U), Thomas Beatty (U of Arizona) Keith Bechtol (U of Wisconsin-Madison), Federico Berlfein (Brandeis U), Antonio Bernardo (U of Sao Paulo), Dillon Brout (U Penn), Robert Butler (Indiana U), Melissa Butner (ETSU), Annalisa Calamida (STScI), Hsin-Yu Chen (Harvard U), Chris Conselice (U of Nottingham), Carlos Contreras (STScI), Jeff Cooke (Swinburne U), Chris D’Andrea (U Penn), Tamara Davis (U Queensland), Reinaldo de Carvalho (UNICSUL), H. Thomas Diehl (Fermilab), Zoheyr Doctor (U Chicago), Alex Drlica-Wagner (Fermilab), Maria Drout (U Toronto), Maya Fishbach (U Chicago), Francisco Forster (U de Chile), Ryan Foley (UCSC), Joshua Frieman (Fermilab & U Chicago), Chris Frohmaier (U of Portsmouth), Ori Fox (STScI), Alyssa Garcia (Brandeis U), Juan Garcia-Bellido (U Autonoma de Madrid), Mandeep Gill (SLAC & Stanford U), Robert Gruendl (NCSA), Will Hartley (U College London), Kenneth Herner (Fermilab), Daniel Holz (U Chicago), Jorge Horvath (U of Sao Paulo), D. Andrew Howell (Las Cumbres Observatory), Richard Kessler (U Chicago), Charles Kilpatrick (UCSC), Nikolay Kuropatkin (Fermilab), Ofer Lahav (U College London), Huan Lin (Fermilab), Andrew Lundgren (U of Portsmouth), Martin Makler (CBPF), Clara Martinez-Vazquez (CTIO/NOAO), Curtis McCully (Las Cumbres Observatory), Mitch McNanna (U of Wisconsin-Madison), Robert Morgan (U of Wisconsin-Madison), Gautham Narayan (STScI), Eric Neilsen (Fermilab), Robert Nichol (U of Portsmouth), Antonella Palmese (Fermilab), Francisco Paz-Chinchon (NCSA & UIUC), Matthew Penny (OSU), Maria Pereira (Brandeis U), Sandro Rembold (UFSM), Armin Rest (STScI & JHU), Livia Rocha (U Sao Paulo), Russell Ryan (STScI), Masao Sako (U Penn), Samir Salim (Indiana U), David Sand (U of Arizona), Luidhy Santana-Silva (Valongo Observatory), Daniel Scolnic (Duke U), Nora Sherman (Fermilab), J. Allyn Smith (Austin Peay State U), Mathew Smith (U of Southampton), Marcelle Soares-Santos (Brandeis U), Lou Strolger (STScI), Riccardo Sturani (UFRN), Mark Sullivan (U of Southampton), Masaomi Tanaka (NAOJ), Nozomu Tominaga (Konan U), Douglas Tucker (Fermilab), Yousuke Utsumi (Stanford U), Stefano Valenti (UC Davis), Kathy Vivas (NOAO/CTIO), Alistair Walker (NOAO/CTIO), Sara Webb (Swinburne U), Matt Wiesner (Benedictine U), Brian Yanny (Fermilab), Michitoshi Yoshida (NAOJ), Alfredo Zenteno (NOAO/CTIO).