Artículos de revistas
On the nature of the hard X-ray sources SWIFT J1907.3-2050, IGR J12123-5802 and IGR J19552+0044
Fecha
2013-11Registro en:
Bernandini, F.; de Martino, D.; Mukai, K.; Falanga, M.; Andruchow, Ileana; et al.; On the nature of the hard X-ray sources SWIFT J1907.3-2050, IGR J12123-5802 and IGR J19552+0044; Oxford University Press; Monthly Notices Of The Royal Astronomical Society; 435; 4; 11-2013; 2822-2834
0035-8711
CONICET Digital
CONICET
Autor
Bernandini, F.
de Martino, D.
Mukai, K.
Falanga, M.
Andruchow, Ileana
Bonnet Bidaud, J. M.
Masetti, N.
Gonzalez Buitrago, D. H.
Mouchet, M.
Tovmassian, G.
Resumen
The INTEGRAL and Swift hard X-ray surveys have identified a large number of new sources, among which many are proposed as Cataclysmic Variables (CVs). Here, we present the first detailed study of three X-ray-selected CVs, Swift J1907.3−2050, IGR J12123−5802 and IGR J19552+0044 based on XMM–Newton, Suzaku, Swift observations and ground-based optical and archival (near-IR) nIR/IR data. Swift J1907.3−2050 is highly variable from hours to months–years at all wavelengths. No coherent X-ray pulses are detected but rather transient features. The X-ray spectrum reveals a multitemperature optically thin plasma absorbed by complex neutral material and a soft blackbody component arising from a small area. These characteristics are remarkably similar to those observed in magnetic CVs. A supra-solar abundance of nitrogen could arise from nuclear processed material from the donor star. Swift J1907.3−2050 could be a peculiar magnetic CV with the second longest (20.82 h) binary period. IGR J12123−5802 is variable in the X-rays on a time-scale of ≳7.6 h. No coherent pulsations are detected, but its spectral characteristics suggest that it could be a magnetic CV of the Intermediate Polar (IP) type. IGR J19552+0044 shows two X-ray periods, ∼1.38 h and ∼1.69 h and an X-ray spectrum characterized by a multitemperature plasma with little absorption. We derive a low accretion rate, consistent with a CV below the orbital period gap. Its peculiar nIR/IR spectrum suggests a contribution from cyclotron emission. It could either be a pre-polar or an IP with the lowest degree of asynchronism.