Constraints on accretion in Ultraluminous X-ray Sources from Spitzer IRS observations of NGC 4485/90: Infrared diagnostic diagrams

dc.creatorVazquez, Gerardo A.
dc.creatorHornschemeier, Ann E.
dc.creatorColbert, Edward
dc.creatorRoberts, Tymothy P.
dc.creatorWard, Martin J.
dc.creatorMalhotra, Sangeeta
dc.date2007-02-09
dc.date.accessioned2026-07-07T12:31:17Z
dc.date.available2026-07-07T12:31:17Z
dc.descriptionConstraining the astrophysical nature of Ultra-Luminous X-ray (ULX) sources, which have X-ray luminosities exceeding 10^39 erg/s, has been elusive due to the optical faintness of any counterparts. With high spectral resolution observations in the ~10-30 microns wavelength range we have conducted an experiment to study six ULX sources in the NGC 4485/90 galaxy pair. We have found that five of the six ULXs, based on mid-infrared spectral diagnostics, show the characteristic higher ionization features that are found in AGN. The sixth source, ULX-1, is consistent with being a supernova remnant. The chief infrared spectral diagnostics used are the ratios of [S III]/[Si II] vs [Ne III}]/[Ne II]. In two instances fits to the continuum and poly aromatic hydrocarbons (PAH) features also indicate higher dust temperatures that are characteristic of accreting sources. Overall, however, we find the continuum is dominated by stellar processes, and the best diagnostic features are the emission lines. High spectral resolution studies in the mid-infrared thus appear to show great promise for determining the astrophysical nature of ULXs.
dc.description2 Figures. ApJ Letters, accepted for publication
dc.identifierhttps://arxiv.org/abs/astro-ph/0702274
dc.identifierhttp://arxiv.org/abs/astro-ph/0702274
dc.identifierAstrophys.J.658:L21-L24,2007
dc.identifierdoi:10.1086/513423
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/216395
dc.subjectAstrophysics
dc.titleConstraints on accretion in Ultraluminous X-ray Sources from Spitzer IRS observations of NGC 4485/90: Infrared diagnostic diagrams
dc.typetext

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