Discovery of a z = 0.65 post-starburst BAL quasar in the DES supernova fields

Dale Mudd , Paul Martini , Suk Sien Tie , Chris Lidman , Richard Mcmahon , Manda Banerji , Tamara Davis , Bradley Peterson , Rob Sharp , Michael Childress , Geraint Lewis , Brad Tucker , Tim Abbot , Filipe Abdalla , Sahar Allam , Aurelien Benoit-Levy (1) , Emmanuel Bertin (1) , David Brooks , A.Camero Rosell , Matias Carrasco Kind , Jorge Carretero , Luiz N. da Costa , Shantanu Desai , Thomas Diehl , Tim Eifler , David Finley , Brenna Flaugher , Karl Glazebrook , Daniel Gruen , Robert Gruendl , Gaston Gutierrez , Samuel Hinton , Klaus Honscheid , David James , Kyler Kuehn , Nikolav Kuropatkin , Edward Macaulay , M.A.G. Maia , Ramon Miquel , Ricardo Ogando , Andres Plazas , Kevin Riel , Eusebio Sanchez , Basillio Santiago , Michael Schubnell , Ignacio Sevilla-Noarbe , R.C. Smith , Marcelle Soares-Santos , Flavia Sobreira , Eric Suchyta , Molly Swanson , Gregory Tarle , Daniel Thomas , Syed Uddin , Alistair Walker , Bonnie Zhang , Nicholas Seymour , Fang Yuan , A. Camero Rosell

1 IAP - Institut d'Astrophysique de Paris

We present the discovery of a z = 0.65 low-ionization broad absorption line (LoBAL) quasar in a post-starburst galaxy in data from the Dark Energy Survey (DES) and spectroscopy from the Australian Dark Energy Survey (OzDES). LoBAL quasars are a minority of all BALs, and rarer still is that this object also exhibits broad Fe ii (an FeLoBAL) and Balmer absorption. This is the first BAL quasar that has signatures of recently truncated star formation, which we estimate ended about 40 Myr ago. The characteristic signatures of an FeLoBAL require high column densities, which could be explained by the emergence of a young quasar from an early, dust-enshrouded phase, or by clouds compressed by a blast wave. The age of the starburst component is comparable to estimates of the lifetime of quasars, so if we assume the quasar activity is related to the truncation of the star formation, this object is better explained by the blast wave scenario.

Mots clés: galaxies: active; quasars: absorption lines; galaxies: starburst

Domaines: Astrophysique [astro-ph]

Dale Mudd, Paul Martini, Suk Sien Tie, Chris Lidman, Richard Mcmahon, et al.. Discovery of a z = 0.65 post-starburst BAL quasar in the DES supernova fields. Mon.Not.Roy.Astron.Soc., 2017, 468 (3), pp.3682-3688. ⟨10.1093/mnras/stx708⟩. ⟨hal-01582576⟩