Infrared identification of IGR J09026-4812 as a Seyfert 1 galaxy

Abstract

IGR J09026-4812 was discovered by INTEGRAL in 2006 as a new hard X-ray source. Thereafter, an observation with Chandra pinpointed a single X-ray source within the ISGRI error circle, showing a hard spectrum, and improving its high-energy localisation to a subarcsecond accuracy. Thus, the X-ray source was associated to the infrared counterpart 2MASS J09023731-4813339 whose JHKs photometry indicated a highly reddened source. The high-energy properties and the counterpart photometry suggested a high-mass X-ray binary with a main sequence companion star located 6.3-8.1 kpc away and with a 0.3-10 keV luminosity of 8e34 erg/s. New optical and infrared observations were needed to confirm the counterpart and to reveal the nature of IGR J09026-4812. We performed optical and near infrared observations on the counterpart 2MASS J09023731-4813339 with the ESO/NTT telescope on March 2007. We achieved photometry and spectroscopy in near infrared wavelengths and photometry in optical wavelengths. The accurate astrometry at both optical and near infrared wavelengths confirmed 2MASS J09023731-4813339 to be the counterpart of IGR J09026-4812. However, the near infrared images show that the source is extended, thus excluding any Galactic compact source possibility. The source spectrum shows three main emission lines identified as the HeI lambda 1.0830 micron line, and the HI Pa_beta and Pa_alpha lines, typical in galaxies with an active galactic nucleus. The broadness of these lines reached values as large as 4000 km/s pointing towards a type 1 Seyfert galaxy. The redshift of the source is z=0.0391(4). Thus, the near infrared photometry and spectroscopy allowed us to classify IGR J09026-4812 as a Seyfert galaxy of type 1.

4 pages, 3 figures, Astronomy and Astrophysics in press

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Cited by in corpus (10)

• The Second INTEGRAL AGN Catalogue
• INTEGRAL/IBIS nine-year Galactic Hard X-Ray Survey
• INTEGRAL/IBIS 7-year All-Sky Hard X-Ray Survey. Part II: Catalog of Sources
• Unveiling the nature of INTEGRAL objects through optical spectroscopy. VIII. Identification of 44 newly detected hard X-ray sources
• INTEGRAL/IBIS 17-yr hard X-ray all-sky survey
• Localizing INTEGRAL Sources with Chandra: X-Ray and Multi-Wavelength Identifications and Energy Spectra
• The nature of fifty Palermo Swift-BAT hard X-ray objects through optical spectroscopy
• INTEGRAL view of AGN
• Chandra Identification of Two AGN Discovered by INTEGRAL
• Investigating the nature of IGR J17454-2919 using X-ray and Near-Infrared observations