Directed searches for continuous gravitational waves from twelve supernova remnants in data from Advanced LIGO’s second observing run

Abstract

We describe directed searches for continuous gravitational waves from twelve well localized nonpulsing candidate neutron stars in young supernova remnants using data from Advanced LIGO's second observing run. We assumed that each neutron star is isolated and searched a band of frequencies from 15 to 150 Hz, consistent with frequencies expected from known young pulsars. After coherently integrating spans of data ranging from 12.0 to 55.9 days using the F-statistic and applying data-based vetoes, we found no evidence of astrophysical signals. We set upper limits on intrinsic gravitational wave amplitude in some cases stronger than 10 −25 , generally about a factor of two better than upper limits on the same objects from Advanced LIGO's first observing run.

Results from an Einstein@Home search for continuous gravitational waves from Cassiopeia A, Vela Jr., and G347.3

“…In-between, the directed searches target locations in the sky that are known or suspected to harbour a neutron star, albeit pulsation shave generally not been observed. Searches of this type include the galactic centre (Piccinni et al 2020;Dergachev et al 2019), young supernova remnants (SNRs) (Ming et al 2019;Papa et al 2020;Abbott et al 2019c;Millhouse et al 2020;Lindblom & Owen 2020;Abbott et al 2021d), glitching pulsars (Fesik & Papa 2020;Abbott et al 2021e) and low-mass X-ray binaries such as Scorpius X-1 (Zhang et al 2021).…”

Search for continuous gravitational waves from Fomalhaut b in the second Advanced LIGO observing run with a hidden Markov model

“…A great deal of work has been carried out to develop methods and conduct searches for CWs. There are three main types of CW searches: (1) targeted searches for pulsars whose sky positions and ephemerides are well measured electromagnetically (e.g., [9,10]), (2) directed searches for neutron stars with known sky positions but unknown rotation frequencies (e.g., [11][12][13][14]), and (3) all-sky searches, surveys done over the whole sky to search for emitting sources (e.g., [15]).…”

Advanced Virgo: Status of the Detector, Latest Results and Future Prospects

“…If the sky position of the source and its rotational parameters are known from EM observations, the so-called "targeted" or "narrow-band" searches are done using matched filtering (see, e.g., [30][31][32][33]). When only the sky position of an interesting source is known (or known with a small uncertainty), "directed" searches are performed, e.g., looking for supernova remnants [34][35][36] or sources in interesting sky regions like the Galactic Center or globular clusters [37], where a huge number of CW emitters are expected to be present. In this case, both modeled or unmodeled searches can be applied.…”

“…In the context of searches for persistent signals, EM information is used to constrain the investigated parameter space. For example, source catalogs such as the latest Fermi-LAT one [206] can be used to identify new CW candidates, such as supernova remnants potentially hosting a NS, for which directed searches are typically performed [34][35][36] using fully coherent or semi-coherent methods. The synergy in this field is twofold: EM information is crucial to limit the parameter space to investigate but, on the other hand, the detection of GWs from a particularly interesting sky region, could be a trigger for astronomers for the observation of new populations of compact objects.…”