J/A+A/662/A98ivo://CDS.VizieR/J/A+A/662/A98doi:10.26093/cds/vizier.36620098CDSBertola E.Vignali C.Lanzuisi G.Dadina M.Cappi M.Gilli R.,Matzeu G.A.Chartas G.Piconcelli E.Comastri A.2023-07-03T14:22:07Z2022-09-30T14:36:54ZCDS support team

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

cds-question@unistra.frquasarsredshiftedx-ray-sourcesWe present new joint XMM-Newton and NuSTAR observations of APM 08279+5255, a gravitationally-lensed, broad-absorption line quasar (z=3.91). After showing a fairly stable flux (f_2-10_~=4-5.5x10^-13^erg/s) from 2000 to 2008, APM 08279+5255 was found in a fainter state in the latest X-ray exposures (f_2-10_~=2.7x10^-13^erg/s), which can likely be ascribed to a lower X-ray activity. Moreover, the 2019 data present a prominent Fe K{alpha} emission line and do not show any significant absorption line. This fainter state, coupled to the first hard X-ray sampling of APM 08279+5255, allowed us to measure X-ray reflection and the high-energy cutoff in this source for the first time. From the analysis of previous XMM-Newton and Chandra observations, X-ray reflection is demonstrated to be a long-lasting feature of this source, but less prominent prior to 2008, possibly due to a stronger primary emission. The estimated high-energy cutoff (E_cut_=99_-35_^+91^keV) sets a new redshift record for the farthest ever measured and places APM 08279+5255 in the allowed region of the compactness-temperature diagram of X-ray coronae, in agreement with previous results on high-z quasars.2022A&A...662A..98Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/662/A98CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/662/A98https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/662/A98http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/662/A98https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/662/A98https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/662/A98http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/662/A98GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/662/A98/tablea1 (Literature low-z measurements collected by Lanzuisi et al. (2019ApJ...875L..20L))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/662/A98/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/662/A98/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/662/A98/tablea1?GETtext/xml+votable180.050000true213.3119839-3.20765470.005555555555555556Cone search capability for table J/A+A/662/A98/tablea2 (Literature low-z measurements collected in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/662/A98/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/662/A98/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/662/A98/tablea2?GETtext/xml+votable180.050000true38.6578417-8.78806110.0055555555555555566/134 1263 1405 2251 2564 3056 3223 3309 4540 4602 5018 5149 5514 5576 5762 5975 6097 6241 6376 6535 6923 7184 7422 7424 7628 7642 7713 7869 7921 8071 8216 8299 8812 8922 9894 10118 10847 10912 10925 10927 10977 11490 11683 12154 13021 13414 13511 13541 14534 14541 14653 14702 14744 14777 14858 14933 15015 15433 15481 15825 15876 16095 16301 16333 16962 17075 17525 17754 17795 17814 18524 19017 19283 19883 20489 21036 21450 21785 21996 22890 22975 23167 23323 23332 24123 24228 25035 25090 25182 25580 25585 25790 25907 25965 26041 26071 26148 26300 26393 26547 27382 27477 27501 27767 27803 27862 27914 28060 28275 28471 28517-28518 28535 28626 28848 29398 29795 30140 31158 31401 32143 32344 32630 32658 33034 33282 33394 33716 34034 34065 34412 34531 34730 34768 34881 34907 34913 35049 35608 36005 36062 36775 36785-36786 36896 37068 37913 38268 38479 38653 38704 38868 38948 39118 39149 39295 39349 39487 39778 40013 40410 40818 41014 41736 41929 41982 42016 42179 43064 43233 43339 43412 43546 43649 43677 43806 43877 44017 44507 44526 44660 44892 45735 45883 46101 46399 46544 46615 46811 47222 47245 47308 48394 48798 49042https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/662/A98?format=asciiX-raydefaultJ/A+A/662/A98/tablea1Literature low-z measurements collected by Lanzuisi et al. (2019ApJ...875L..20L)SimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharn_Name[*] Note (1)meta.notecharzRedshiftsrc.redshiftdoublelogL2-10Logarithm of the 2-10keV luminositylog(1e-07W)phys.luminosity;em.X-rayfloatl_EcutLimit flag on Ecutmeta.code.errorcharEcutHigh-energy cutoffkeVem.energyintE_Ecut? Error on Ecut (upper value)keVstat.error;stat.maxintnullablee_Ecut? Error on Ecut (lower value)keVstat.errorintnullableFlag[1/2] Telescope flag (2)meta.code.errorintRefsReferences (3)meta.ref;pos.framechar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/A+A/662/A98/tablea2Literature low-z measurements collected in this workzRedshiftsrc.redshiftdoubleSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource namemeta.id;meta.maincharn_Name[*] Note (1)meta.notecharlogL2-10Logarithm of the 2-10keV luminositylog(1e-07W)phys.luminosity;em.X-rayfloatl_EcutLimit flag on Ecutmeta.code.errorcharEcutHigh-energy cutoffkeVem.energyintE_Ecut? Error on Ecut (upper value)keVstat.error;stat.maxintnullablee_Ecut? Error on Ecut (lower value)keVstat.errorintnullableFlag[1/2] Telescope flag (2)meta.code.errorintRefsReferences (3)meta.ref;pos.framechar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main