Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300
We report on the unveiling of the nature of the unidentified X-ray source 3XMM J005450.3–373849 as a Seyfert-2 galaxy located behind the spiral galaxy NGC 300 using <i>Hubble Space Telescope</i> data, new spectroscopic Gemini observations and available <i>XMM–Newton</i> and &...
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Formato: | Articulo |
Lenguaje: | Inglés |
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2016
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Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/95744 https://ri.conicet.gov.ar/11336/25953 https://academic.oup.com/mnras/article-abstract/460/2/1640/2608926/Discovery-of-a-deep-Seyfert-2-galaxy-at-z-0-222 |
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I19-R120-10915-95744 |
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dspace |
institution |
Universidad Nacional de La Plata |
institution_str |
I-19 |
repository_str |
R-120 |
collection |
SEDICI (UNLP) |
language |
Inglés |
topic |
Astronomía galaxies: Seyfert X-rays: galaxies X-rays: individual: 3XMM J005450.3–373849 X-rays: individual: XMMU J005450.0–373853 |
spellingShingle |
Astronomía galaxies: Seyfert X-rays: galaxies X-rays: individual: 3XMM J005450.3–373849 X-rays: individual: XMMU J005450.0–373853 Combi, Jorge Ariel García, Federico Rodríguez, María Jimena Gamen, Roberto Claudio Cellone, Sergio Aldo Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300 |
topic_facet |
Astronomía galaxies: Seyfert X-rays: galaxies X-rays: individual: 3XMM J005450.3–373849 X-rays: individual: XMMU J005450.0–373853 |
description |
We report on the unveiling of the nature of the unidentified X-ray source 3XMM J005450.3–373849 as a Seyfert-2 galaxy located behind the spiral galaxy NGC 300 using <i>Hubble Space Telescope</i> data, new spectroscopic Gemini observations and available <i>XMM–Newton</i> and <i>Chandra</i> data. We show that the X-ray source is positionally coincident with an extended optical source, composed of a marginally resolved nucleus/bulge, surrounded by an elliptical disc-like feature and two symmetrical outer rings. The optical spectrum is typical of a Seyfert-2 galaxy redshifted to z = 0.222 ± 0.001, which confirms that the source is not physically related to NGC 300. At this redshift the source would be located at 909 ± 4 Mpc (comoving distance in the standard model). The X-ray spectra of the source are well fitted by an absorbed power-law model. By tying N<sub>H</sub> between the six available spectra, we found a variable index Γ running from ∼2 in 2000–2001 to 1.4–1.6 in the 2005–2014 period. Alternatively, by tying Γ, we found variable absorption columns of N<sub>H</sub> ∼ 0.34 × 10<sup>−22</sup> cm<sup>−2</sup> in 2000–2001, and 0.54−0.75 × 10<sup>−22</sup> cm<sup>−2</sup> in the 2005–2014 period. Although we cannot distinguish between a spectral or absorption origin, from the derived unabsorbed X-ray fluxes, we are able to assure the presence of long-term X-ray variability. Furthermore, the unabsorbed X-ray luminosities of 0.8–2 × 10<sup>43</sup> erg s<sup>−1</sup> derived in the X-ray band are in agreement with a weakly obscured Seyfert-2 AGN at z ≈ 0.22. |
format |
Articulo Articulo |
author |
Combi, Jorge Ariel García, Federico Rodríguez, María Jimena Gamen, Roberto Claudio Cellone, Sergio Aldo |
author_facet |
Combi, Jorge Ariel García, Federico Rodríguez, María Jimena Gamen, Roberto Claudio Cellone, Sergio Aldo |
author_sort |
Combi, Jorge Ariel |
title |
Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300 |
title_short |
Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300 |
title_full |
Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300 |
title_fullStr |
Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300 |
title_full_unstemmed |
Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300 |
title_sort |
discovery of a deep seyfert-2 galaxy at z = 0.222 behind ngc 300 |
publishDate |
2016 |
url |
http://sedici.unlp.edu.ar/handle/10915/95744 https://ri.conicet.gov.ar/11336/25953 https://academic.oup.com/mnras/article-abstract/460/2/1640/2608926/Discovery-of-a-deep-Seyfert-2-galaxy-at-z-0-222 |
work_keys_str_mv |
AT combijorgeariel discoveryofadeepseyfert2galaxyatz0222behindngc300 AT garciafederico discoveryofadeepseyfert2galaxyatz0222behindngc300 AT rodriguezmariajimena discoveryofadeepseyfert2galaxyatz0222behindngc300 AT gamenrobertoclaudio discoveryofadeepseyfert2galaxyatz0222behindngc300 AT cellonesergioaldo discoveryofadeepseyfert2galaxyatz0222behindngc300 |
bdutipo_str |
Repositorios |
_version_ |
1764820492279087107 |