An ultrafast outflow in the black hole candidate MAXI J1810-222?

The transient X-ray source MAXI J1810−222 was discovered in 2018 and has been active ever since. A long combined radio and X-ray monitoring campaign was performed with Australia Telescope Compact Array and Swift, respectively. It has been proposed that MAXI J1810−222 is a relatively distant black ho...

Descripción completa

Detalles Bibliográficos
Autores: Santo, Melania del, Pinto, Ciro, Marino, Alessio, D'Aí, Antonino, Petrucci, P.-O., Malzac, J., Ferreira, J., Pintore, Fabio, Motta, S. E., Russell, T. D., Segreto, A., Sanna, Andrea
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/337594
Acceso en línea:http://hdl.handle.net/10261/337594
Access Level:acceso abierto
Palabra clave:Accretion
Accretion discs
Stars: winds
Outflows
X-rays: binaries
X-rays: individual: MAXI J1810−222
Descripción
Sumario:The transient X-ray source MAXI J1810−222 was discovered in 2018 and has been active ever since. A long combined radio and X-ray monitoring campaign was performed with Australia Telescope Compact Array and Swift, respectively. It has been proposed that MAXI J1810−222 is a relatively distant black hole X-ray binary, albeit showing a very peculiar outburst behaviour. Here, we report on the spectral study of this source making use of a large sample of NICER observations performed between 2019 February and 2020 September. We detected a strong spectral absorption feature at ∼1 keV, which we have characterized with a physical photoionization model. Via a deep scan of the parameters space, we obtained evidence for a spectral-state dependent outflow, with mildly relativistic speeds. In particular, the soft and intermediate states point to a hot plasma outflowing at 0.05–0.15c. This speeds rule-out thermal winds and hence, they suggest that such outflows could be radiation pressure or (most likely) magnetically driven winds. Our results are crucial to test current theoretical models of wind formation in X-ray binaries.