SRG/ART-XC and NuSTAR observations of the X-ray pulsar GRO J1008-57 in the lowest luminosity state
The first proper paper by ART-XC onboard SRG is out!. GRO J1008-57 was the first source where we understood that accretion in quiescent BeXRBs might occur from a cold, non-ionized, low-viscosity accretion disk, much like in quiet periods of dwarf novae. The statistics of Swift/XRT and short Chandra pointing did not permit us at the time, however, to definitively prove that also the pulsar remains active, so we tried to get XMM data several times to do that, but without much success. Fortunately, the source was observed in quiescence by ART-XC telescope during the performance verification phase of SRG (hosting ART-XC and eRosita telescopes). This allowed to detect pulsations, and study the source properties in detail using the follow-up DDT NuSTAR observation
As you can see, our results show that pulsations from GRO J1008-57 in quiescence are detected both by NuSTAR and ART-XC, and the broadband X-ray spectrum resembles that of other low luminosity X-ray pulsars like X Persei, GX 304-1, 1A 0535+262 or SGR 0755−2933. Congratulations to ART-XC team on this result!