TY - JOUR
T1 - The hypersoft state of Cygnus X-3
T2 - A key to jet quenching in X-ray binaries?
AU - Koljonen, K. I.I.
AU - Maccarone, T.
AU - McCollough, M. L.
AU - Gurwell, M.
AU - Trushkin, S. A.
AU - Pooley, G. G.
AU - Piano, G.
AU - Tavani, M.
N1 - Publisher Copyright:
© ESO 2018.
PY - 2018/4/1
Y1 - 2018/4/1
N2 - Context. Cygnus X-3 is a unique microquasar in the Galaxy hosting a Wolf-Rayet companion orbiting a compact object that most likely is a low-mass black hole. The unique source properties are likely due to the interaction of the compact object with the heavy stellar wind of the companion. Aim. In this paper, we concentrate on a very specific period of time prior to the massive outbursts observed from the source. During this period, Cygnus X-3 is in a so-called hypersoft state, in which the radio and hard X-ray fluxes are found to be at their lowest values (or non-detected), the soft X-ray flux is at its highest values, and sporadic γ-ray emission is observed. We use multiwavelength observations to study the nature of the hypersoft state. Methods. We observed Cygnus X-3 during the hypersoft state with Swift and NuSTAR in X-rays and SMA, AMI-LA, and RATAN-600 in the radio. We also considered X-ray monitoring data from MAXI and γ-ray monitoring data from AGILE and Fermi. Results. We found that the spectra and timing properties of the multiwavelength observations can be explained by a scenario in which the jet production is turned off or highly diminished in the hypersoft state and the missing jet pressure allows the wind to refill the region close to the black hole. The results provide proof of actual jet quenching in soft states of X-ray binaries.
AB - Context. Cygnus X-3 is a unique microquasar in the Galaxy hosting a Wolf-Rayet companion orbiting a compact object that most likely is a low-mass black hole. The unique source properties are likely due to the interaction of the compact object with the heavy stellar wind of the companion. Aim. In this paper, we concentrate on a very specific period of time prior to the massive outbursts observed from the source. During this period, Cygnus X-3 is in a so-called hypersoft state, in which the radio and hard X-ray fluxes are found to be at their lowest values (or non-detected), the soft X-ray flux is at its highest values, and sporadic γ-ray emission is observed. We use multiwavelength observations to study the nature of the hypersoft state. Methods. We observed Cygnus X-3 during the hypersoft state with Swift and NuSTAR in X-rays and SMA, AMI-LA, and RATAN-600 in the radio. We also considered X-ray monitoring data from MAXI and γ-ray monitoring data from AGILE and Fermi. Results. We found that the spectra and timing properties of the multiwavelength observations can be explained by a scenario in which the jet production is turned off or highly diminished in the hypersoft state and the missing jet pressure allows the wind to refill the region close to the black hole. The results provide proof of actual jet quenching in soft states of X-ray binaries.
KW - Accretion, accretion disks
KW - Binaries: close
KW - Stars: individual: Cyg X-3
KW - Stars: winds, outflows
KW - X-rays: binaries
UR - http://www.scopus.com/inward/record.url?scp=85045514653&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201732284
DO - 10.1051/0004-6361/201732284
M3 - Article
AN - SCOPUS:85045514653
SN - 0004-6361
VL - 612
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A27
ER -