J/A+A/416/1037ivo://CDS.VizieR/J/A+A/416/1037doi:10.26093/cds/vizier.34161037CDSHulleman F.van Kerkwijk M.H.Kulkarni S.R.2004-05-13T05:37:58Z2004-05-13T05:37:50ZCDS support team

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

cds-question@unistra.frpulsarsx-ray-sourcesinfrared-photometryvisible-astronomybroad-band-photometryastrometryWe present new optical and infrared observations of the counterpart to the Anomalous X-ray Pulsar (AXP) 4U 0142+61 taken with the Keck I telescope. The counterpart is found to be variable in the infrared. This contrasts with our optical observations, which do not show any evidence for variability. Apart from the variability the AXP shows a remarkable spectral energy distribution. In particular, we find a sudden drop in flux going from V to B, presumably due to a spectral feature. We compare our results to those obtained for the two other securely identified AXP counterparts, to 1E 2259+586 and 1E 1048.1-5937. 4U 0142+61 is very similar to the former source in its X-ray timing and spectral properties, and we find that this similarity extends to the quiescent infrared to X-ray flux ratio. For 1E 1048.1-5937, which has different X-ray properties, the situation is less clear: in one observation, the infrared to X-ray flux ratio was much larger, but another observation gave an upper limit which is consistent with that observed for 4U 0142+61. Assuming the quiescent ratios are all similar, we estimate the optical and infrared brightnesses for the three AXPs that remain to be identified as well as for the four Soft Gamma-ray Repeaters. We also discuss briefly how the observed optical and infrared emission might arise, in particular in the context of the magnetar model.2004A&A...416.1037Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/416/1037CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/416/1037https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/416/1037http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/416/1037https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/416/1037https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/416/1037http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/416/1037GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/416/1037/table3 (BVRI photometry for objects in the field of AXP 4U 0142+61)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/416/1037/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/416/1037/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/416/1037/table3?GETtext/xml+votable180.050000true26.593362561.750886110.0055555555555555566/3633https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/416/1037?format=asciiX-rayOpticalInfraredRadiodefaultJ/A+A/416/1037/table3BVRI photometry for objects in the field of AXP 4U 0142+61recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainBmag? B band magnitude (1)magphot.mag;em.opt.Bfloatnullablee_Bmag? Error in B band magnitudemagstat.errorfloatnullableVmag? V band magnitudemagphot.mag;em.opt.Vfloatnullablee_Vmag? Error in V band magnitudemagstat.errorfloatnullableRmag? R band magnitudemagphot.mag;em.opt.Rfloatnullablee_Rmag? Error in R band magnitudemagstat.errorfloatnullableImag? I band magnitudemagphot.mag;em.opt.Ifloatnullablee_Imag? Error in I band magnitudemagstat.errorfloatnullableKmag? K band magnitude (1), (2)magphot.mag;em.IR.Kfloatnullablee_Kmag? Error in K band magnitudemagstat.errorfloatnullableIdentIdentification (3)meta.id;meta.maincharOtherPrevious identification (4)meta.idcharFlag[F] bad photometry flag (5)meta.codechar