Details

Autor(en) / Beteiligte

• Bellm, Eric C.
• Wang, Yuankun
• van Roestel, Jan
• Phillipson, Rebecca A.
• Coughlin, Michael W.
• Tomsick, John A.
• Groom, Steven L.
• Healy, Brian
• Purdum, Josiah
• Rusholme, Ben
• Sollerman, Jesper
• Bealo, Peter
• Lora, Stefano
• Muyllaert, Eddy
• Peretto, Ivo
• Schwendeman, Erik J.

Titel

An Optically Discovered Outburst from XTE J1859+226

Ist Teil von

• The Astrophysical journal, 2023-10, Vol.956 (1), p.21

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2023

Quelle

Elektronische Zeitschriftenbibliothek - Freely accessible e-journals

Beschreibungen/Notizen

• Abstract Using the Zwicky Transient Facility, in 2021 February we identified the first known outburst of the black hole X-ray transient XTE J1859+226 since its discovery in 1999. The outburst was visible at X-ray, UV, and optical wavelengths for less than 20 days, substantially shorter than its full outburst of 320 days in 1999, and the observed peak luminosity was 2 orders of magnitude lower. Its peak bolometric luminosity was only 2 × 10 35 erg s −1 , implying an Eddington fraction of about 3 × 10 −4 . The source remained in the hard spectral state throughout the outburst. From optical spectroscopy measurements we estimate an outer disk radius of 10 11 cm. The low observed X-ray luminosity is not sufficient to irradiate the entire disk, but we observe a surprising exponential decline in the X-ray light curve. These observations highlight the potential of optical and infrared synoptic surveys to discover low-luminosity activity from X-ray transients.