J/ApJ/904/49ivo://CDS.VizieR/J/ApJ/904/49doi:10.26093/cds/vizier.19040049CDSMiller J.M.Swihart S.J.Strader J.Urquhart R.Aydi E.Chomiuk L.,Dage K.C.Kawash A.Shishkovsky L.Sokolovsky K.V.2022-06-13T10:00:23Z2022-05-30T07:06:40ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frneutron-starsvisible-astronomyspectroscopyinfrared-photometryphotometryWe report the discovery of a variable optical and X-ray source within the error ellipse of the previously unassociated Fermi Large Area Telescope {gamma}-ray source 4FGLJ0407.7-5702. A 22ks observation from XMM-Newton/European Photon Imaging Camera (EPIC) shows an X-ray light curve with rapid variability and flaring. The X-ray spectrum is well fit by a hard power law with {Gamma}=1.7. Optical photometry taken over several epochs is dominated by aperiodic variations of moderate amplitude. Optical spectroscopy with Southern Astrophysical Research (SOAR) and Gemini reveals a blue continuum with broad and double-peaked H and He emission, as expected for an accretion disk around a compact binary. Overall, the optical, X-ray, and {gamma}-ray properties of 4FGLJ0407.7-5702 are consistent with a classification as a transitional millisecond pulsar in the subluminous disk state. We also present evidence that this source is more distant than other confirmed or candidate transitional millisecond pulsar binaries, and that the ratio of X-ray to {gamma}-ray flux is a promising tool to help identify such binaries, indicating that a more complete census for these rare systems is becoming possible.2020ApJ...904...49Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/904/49CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)J/A+A/588/A103 : Second ROSAT all-sky survey source catalog (Boller+, 2016)J/A+A/594/A116 : HI4PI spectra and column density maps (HI4PI team+, 2016)J/ApJ/831/89 : Eclipsing LMXB at center of 3FGL J0427.9-6704 (Strader+, 2016)J/ApJ/866/83 : Opt/NIR obs. 1FGLJ1417.7-4407 neutron star (Swihart+, 2018)J/ApJ/872/42 : Opt. spectroscopy redback ms pulsar binaries (Strader+, 2019)J/AJ/158/16 : Identification of RR Lyrae stars from DES (Stringer+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/904/49https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/904/49http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/904/49https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/904/49https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/904/49http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/904/49GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/904/49/fig7Rectified coadded SOAR optical spectra of 4FGL J0407.7-5702recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintWave[4001/7151] Wavelength0.1nmem.wlintFlux[0.73/2.11] Rectified flux (10^-13^erg/s/cm^2^)phot.flux.density;em.optdoubleJ/ApJ/904/49/fig8SOAR g' and i' optical photometry of 4FGL J0407.7-5702, taken on 2019 December 17recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObs.MMonth of the observation (1)time.epochcharBJD[2458834/2458862] Barycentric Julian date of observationdtime.epochdoubleomag[19.6/20.8] Apparent Magnitude in Bandmagphot.mag;em.optfloate_omag[0.009/0.03] Uncertainty in omagmagstat.error;phot.magfloatFiltSDSS filter used; g' or i'meta.notechar