##acl EroXxxAdminGroup:admin,read,write,delete,revert EroXxxGroup:read,write AnyGroup:read #format wiki #language en ## replace Xxx with group name and nn with proposal number == EroCompact EC Proposal 58/59/60 == ## enter Changed line whenever a substantial update was made ==== Proposal Date : 02-Nov-2021 ==== * Changed : 02-Nov-2021 by AdrianaPires : Submission ||||||||'''External Collaborator'''|| || '''Name''' || '''First name''' || '''Institute''' || '''email''' || || Ashton || Gregory || Royal Holloway, University of London || gregory.ashton@ligo.org || || Ho || Wynn || Harverford College || who@haverford.edu || || Lasky || Paul || Monash University || paul.lasky@monash.edu || ||||||||'''eROSITA_DE Proposing Member'''|| || '''Name''' || '''First name''' || '''Institute''' || '''email''' || || Pires || Adriana || AIP || apires@aip.de || ==== Scientific Proposal ==== The LIGO Scientific Collaboration and Virgo Collaboration have so far announced about 50 detections of gravitational waves, all of them associated with mergers of compact objects. These signals are transient and bright, typically presenting a strain amplitude of 10-21 for most of the time. By contrast, continuous gravitational waves (CWs) – a persistent though orders of magnitude weaker train of nearly monochromatic waves – have not yet been identified in the LIGO/Virgo observing runs. A spinning, slightly deformed, neutron star is one of the most promising candidate to trigger a first detection. While coherent time searches for CWs are feasible for pulsars with a precise timing solution and known sky location, blind, all-sky searches rely on semi-coherent search methods and the shared computing power of the Einstein@Home initiative. We propose to investigate the error circle (~10 arcmin) of CW candidates selected from the Einstein@Home all-sky search, with the immediate goal to identify their X-ray counterpart in the eROSITA survey data. While the “loudest” CW emitters are expected to be young and energetic spin-powered pulsars, blind searches will put forward candidates lacking bright electromagnetic counterparts (e.g. a previously known pulsar wind nebula or supernova remnant). This opens the interesting prospect to associate CW candidates with peculiar groups of X-ray thermally-emitting isolated neutron stars, particularly those of central compact objects (CCOs) in supernova remnants and X-ray dim isolated neutron stars (XDINS), which may have evolved differently than most neutron stars that are known in our Galaxy. The selection of suitable CW candidates, a complex hierarchical process involving multiple stringent veto stages, requires not only expertise on the field of gravitational physics but also specific knowledge on gravitational wave detectors and Einstein@Home searches. We are proposing Greg Ashton, Wynn Ho, and Paul Lasky as members of the LIGO Scientific Collaboration and Virgo Collaboration, as external collaborators in this project. The most promising CW candidates will be selected for deeper investigations in X-rays, especially with NICER TOOs (Wynn Ho is a Science Team member) and XMM-Newton (GO proposals). Follow-up observations in the optical, radio, and gamma-ray regimes may also be envisaged. ==== List of Potential Collaborators within eROSITA_DE ==== Axel Schwope, Jan Kurpas (AIP), Werner Becker (MPE). ==== Expected Outcome ==== Scientific paper; catalogue of counterparts. ==== Expected duration of the project ==== Initially one year.