Submillimeter array identification of the millimeter-selected galaxy SSA22-AzTEC1: a protoquasar in a protocluster?
We present results from Submillimeter Array (SMA) 860 μm subarcsecond astrometry and multiwavelength observations of the brightest millimeter (S₁․₁ₘₘ = 8.4 mJy) source, SSA22-AzTEC1, found near the core of the SSA22 protocluster that is traced by Lyα-emitting galaxies at z = 3.09. We identify a 860...
| Autor: | |
|---|---|
| Formato: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2010 |
| País: | México |
| Recursos: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositorio: | Repositorio Institucional del INAOE |
| Idioma: | inglés |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/1519 |
| Acesso em linha: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1519 |
| Access Level: | acceso abierto |
| Palavra-chave: | info:eu-repo/classification/Inspec/Galaxies: formation info:eu-repo/classification/Inspec/Galaxies: starburst info:eu-repo/classification/Inspec/Infrared: galaxies info:eu-repo/classification/Inspec/Quasars: general info:eu-repo/classification/Inspec/Submillimeter: galaxies info:eu-repo/classification/Inspec/X-rays: galaxies info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/21 |
| Resumo: | We present results from Submillimeter Array (SMA) 860 μm subarcsecond astrometry and multiwavelength observations of the brightest millimeter (S₁․₁ₘₘ = 8.4 mJy) source, SSA22-AzTEC1, found near the core of the SSA22 protocluster that is traced by Lyα-emitting galaxies at z = 3.09. We identify a 860 μm counterpart with a flux density of S₈₆₀ μm = 12.2 ± 2.3 mJy and absolute positional accuracy that is better than 0“.3. At the SMA position, we find radio-to-mid-infrared counterparts, whilst no object is found in Subaru optical and near-infrared deep images at wavelengths ≤1μm (J > 25.4 in AB, 2σ). The photometric redshift estimate, using flux densities at ≥24 μm, indicates zₚₕₒₜ = 3.19⁺⁰˙²⁶₋₀․₃₅, consistent with the protocluster redshift. We then model the near-to-mid-infrared spectral energy distribution (SED) of SSA22-AzTEC1, and find that the SED modeling requires a large extinction (A ≈ 3.4 mag) of starlight from a stellar component with Mₛₜₐᵣ ∼ 10¹⁰˙⁹M⊙, assuming z = 3.1. Additionally, we find a significant X-ray counterpart with a very hard spectrum (Γeff = −0.34⁺⁰˙⁵⁷₋₀.₆₁), strongly suggesting that SSA22-AzTEC1 harbors a luminous active galactic nuclei (AGNs; L ≈ 3 × 10⁴⁴ erg s⁻¹) behind a large hydrogen column (N ∼ 10²⁴ cm⁻²). The AGN, however, is responsible for only ∼10% of the bolometric luminosity of the host galaxy, and therefore the star formation activity likely dominates the submillimeter emission. It is possible that SSA22-AzTEC1 is the first example of a protoquasar growing at the bottom of the gravitational potential underlying the SSA22 protocluster. |
|---|