A search for signatures of interactions of X-ray binary outflows with their environments with ALMA

Abstract

We observed the X-ray binaries Cir X-1, Sco X-1, GRS 1915+105, GX 13+1, and Cyg X-1 with the Atacama Large Millimeter/submillimeter Array (ALMA). Unresolved continuum emission is found at the positions of all the sources at a frequency of 92 GHz, with flux densities ranging between 0.8 and 10 mJy beam−1. In all cases the emission can be associated with jets that have been extensively observed at lower frequencies. We searched for line emission from Hα recombination, SiO, H2O, and CH3OH at the positions of all the sources and, for Cir X-1 and Cyg X-1, also at regions where shocks associated with an interaction between the jet and the interstellar medium had previously been observed. The search did not yield any significant detection, resulting in 3σ upper limits between 0.65 and 3.7 K km s−1 for the existence of line emission in these regions. In contrast, we detected spatially unresolved SiO emission in the field of view of GX 13+1, and we tentatively associate this emission with a SiO maser in a potential young stellar object or evolved star. We also found spatially extended line emission at two additional sites in the field of view of GX 13+1 that we tentatively associate with emission from SO and CH3OH; we speculate that it may be associated with a star-forming region, but again we cannot rule out alternative origins such as emission from evolved stars.

Matter ejections behind the highs and lows of the transitional millisecond pulsar PSR J1023+0038

“…The millimetre emission is unresolved, implying a size for the emission region smaller than ≈6 × 10 15 cm (this corresponds to ≈7 × 10 4 times the orbital separation of the system; Archibald et al 2013). Millimetre/sub-millimetre continuum emission has been firmly detected from a number of transiently accreting stellarmass black holes (Paredes et al 2000;Ogley et al 2000;Fender et al 2000Fender et al , 2001Ueda et al 2002;Russell et al 2013aRussell et al , 2020van der Horst et al 2013;Tetarenko et al 2015Tetarenko et al , 2017Tetarenko et al , 2019Tetarenko et al , 2021de Haas et al 2021;Koljonen & Hovatta 2021;Díaz Trigo et al 2021) and in three accreting NSs so far: the persistent systems 4U 1728−34 and 4U 1820−30 (Díaz Trigo et al 2017) and the transient accreting millisecond pulsar Aql X-1 (Díaz Trigo et al 2018). In these cases, however, such emission has been detected during accretion states that are seemingly different from the X-ray sub-luminous disc state attained by J1023 at the epoch of our ALMA observations, as detailed below.…”