Optical nebular emission following the most luminous outburst of Aquila X-1

Panizo-Espinar, G.; Muñoz-Darias, T.; Armas Padilla, M.; Jiménez-Ibarra, F.; Casares, J.; Mata Sánchez, D.
Referencia bibliográfica

Astronomy and Astrophysics

Fecha de publicación:
6
2021
Número de autores
6
Número de autores del IAC
5
Número de citas
6
Número de citas referidas
6
Descripción
Aquila X-1 is a prototypical neutron star low mass X-ray binary and one of the most studied X-ray transients. We present optical spectroscopy obtained with the Gran Telescopio Canarias (10.4 m) during the 2016 outburst, the brightest recorded in recent times and which showed a standard evolution with hard and soft accretion states. Our dataset includes a dense coverage of the brightest phases of the event, as well as the decay towards quiescence. We searched for optical winds by studying the profiles and evolution of the main emission lines and found no indisputable wind signatures, such as P-Cyg profiles. Nonetheless, our detailed analysis of the particularly strong and broad Hα emission line, detected at the end of the outburst, is consistent with the presence of a nebular phase produced by optically thin ejecta at ∼800 km s−1 or, alternatively, an extended disc atmosphere. We discuss these possibilities as well as the similarities with the phenomenology observed in other black hole and neutron star systems. Our study suggests that optical nebular phases might be a relatively common observational feature during the late stages of low mass X-ray binaries' outbursts, enabling us to probe the presence of outflows at low-to-intermediate orbital inclinations.
Proyectos relacionados
Agujero negro en erupción
Agujeros negros, estrellas de neutrones, enanas blancas y su entorno local

Los agujeros negros y estrellas de neutrones en binarias de rayos-X son laboratorios únicos para explorar la física de estos objetos compactos. No solo permiten confirmar la existencia de agujeros negros de origen estelar a través de mediciones dinámicas de sus masas, sino que también permiten investigar el comportamiento de la materia y la

Montserrat
Armas Padilla