Results from an Einstein@Home deep search for continuous gravitational waves from G347.3 and Vela Jr in LIGO O2 data

We present results of a search for periodic gravitational wave signals with frequency between 20 and 900 Hz, from the neutron star in the supernova remnants G347.3-0.5 and Vela Jr, using LIGO O2 public data. The search is deployed on the volunteer computing project Einstein@Home(E@H), with thousands of participants donating compute cycles to make this endevour possible. The LIGO O3 data is used to follow-up search the candidates which are found in O2 E@H search. At the current time (mid Jan 2023), the O3 follow-up search is going on, so we don't know if there will be some interesting signal candidates yet. Even if we find no significant signal candidate, we can still set the most constraining upper limits to date on the amplitude of gravitational wave signals from the target, corresponding to deformations of neutron stars below 1e-6 in a large part of the band. At the frequency of best strain sensitivity, near 166 Hz, we set 90% confidence upper limits on the gravitational wave intrinsic amplitude of h0_{90%}≈6.0e-26. Over most of the frequency range our upper limits are a factor of 20 smaller than the indirect age-based upper limit for source G347.3.  For the source Vela Jr the h0_{90%} uplimt we set is 6.6e-26.