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相关论文: Active galactic nuclei catalog from the AKARI NEP …

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We utilized the Edelson and Malkan (2012) and Stern et al. (2012) selection techniques and other methods to identify AGN candidates that were monitored during the Kepler prime and K2 missions. Subsequent to those observations, we obtained…

星系天体物理 · 物理学 2025-05-06 Tran Tsan , Matthew Malkan , Rick Edelson , Krista Smith , Daniel Stern , Matthew Graham

We present the survey strategy and the data characteristics of the North Ecliptic Pole (NEP) Wide Survey of AKARI. The survey was carried out for about one year starting from May 2006 with 9 passbands from 2.5 to 24 micron and the areal…

We present a new method to predict the line-of-sight column density (NH) values of active galactic nuclei (AGN) based on mid-infrared (MIR), soft, and hard X-ray data. We developed a multiple linear regression machine learning algorithm…

Since a large fraction of active galactic nuclei (AGN) is missed in common UV-excess surveys and is even hard to find in radio, near-IR and X-ray surveys, we have used a new AGN selection technique which is expected to be not affected by…

We present a machine learning model to classify Active Galactic Nuclei (AGN) and galaxies (AGN-galaxy classifier) and a model to identify type 1 (optically unabsorbed) and type 2 (optically absorbed) AGN (type 1/2 classifier). We test…

星系天体物理 · 物理学 2021-12-08 Serena Falocco , Francisco J. Carrera , Josefin Larsson

We present measurements of black hole (BH) properties of 861 Type-1 active galactic nuclei (AGNs) in the North Ecliptic Pole (NEP)-Wide field. These AGNs are detected in both optical and mid-infrared (MIR) surveys and are identified as…

We show that using mid-IR color selection to find active galactic nuclei (AGN) is as effective in dense stellar fields such as the Magellanic Clouds as it is in extragalactic fields with low stellar densities using comparisons between the…

宇宙学与河外天体物理 · 物理学 2009-08-10 Szymon Kozlowski , Christopher S. Kochanek

We present the source catalog and the properties of the $B-, R-$, and $I-$band images obtained to support the {\it AKARI} North Ecliptic Pole Wide (NEP-Wide) survey. The NEP-Wide is an {\it AKARI} infrared imaging survey of the north…

宇宙学与河外天体物理 · 物理学 2010-10-19 Yiseul Jeon , Myungshin Im , Mansur Ibrahimov , Hyung Mok Lee , Induk Lee , Myung Gyoon Lee

We present a spectroscopic and photometric analysis of a sample of 416,288 galaxies from the Sloan Digital Sky Survey (SDSS) matched to mid-infrared (mid-IR) data from the Wide-Field Infrared Survey Explorer (WISE). By using a new…

We present a new catalogue of mid-IR sources using the AKARI NEP-Deep survey. The InfraRed Camera (IRC) onboard AKARI has a comprehensive mid-IR wavelength coverage with 9 photometric bands at 2 - 24 micron. We utilized all of these bands…

宇宙学与河外天体物理 · 物理学 2012-01-05 T. Takagi , H. Matsuhara , T. Goto , H. Hanami , M. Im , T. Ishigaki , H. M. Lee , M. Malkan , Y. Ohyama , S. Oyabu , C. P. Pearson , S. Serjeant , T. Wada , G. J. White

We present an initial analysis of AKARI 18um-selected galaxies using all 9 photometric bands at 2-24um available in the InfraRed Camera (IRC), in order to demonstrate new capabilities of AKARI cosmological surveys. We detected 72 sources at…

Galaxy clusters provide an excellent probe in various research fields in astrophysics and cosmology. However, the number of galaxy clusters detected so far in the $AKARI$ North Ecliptic Pole (NEP) field is limited. In this work, we provide…

We present a catalog of optical and infrared identifications (ID) of X-ray sources in the AKARI North Ecliptic Pole (NEP) Deep field detected with Chandra covering $\sim 0.34\,{\rm deg^{2}}$ with 0.5-2 keV flux limits ranging $\sim 2…

We present the result of a spectroscopic campaign targeting Active Galactic Nucleus (AGN) candidates selected using a novel unsupervised machine-learning (ML) algorithm trained on optical and mid-infrared (mid-IR) photometry. AGN candidates…

星系天体物理 · 物理学 2024-02-09 Raphael E. Hviding , Kevin N. Hainline , Andy D. Goulding , Jenny E. Greene

The AKARI North Ecliptic Pole (NEP) survey consists of two survey projects: NEP-Deep (0.5 sq.deg) and NEP-Wide (5.4 sq.deg), providing with tens of thousands of galaxies. A continuous filter coverage in the mid-infrared wavelengths (7, 9,…

Galaxy mergers play an important role in the growth of galaxies and their supermassive black holes. Simulations suggest that tidal interactions could enhance black hole accretion, which can be tested by the fraction of binary active…

星系天体物理 · 物理学 2015-06-23 Hai Fu , A. D. Myers , S. G. Djorgovski , Lin Yan , J. M. Wrobel , A. Stockton

Identifying Active Galactic Nuclei (AGNs) through their X-ray emission is efficient, but necessarily biased against X-ray-faint objects. We aim to characterize this bias by comparing X-ray-selected AGNs to the ones identified through…

Variability is a main property of active galactic nuclei (AGN) and it was adopted as a selection criterion using multi epoch surveys conducted for the detection of supernovae (SNe). We have used two SN datasets. First we selected the AXAF…

星系天体物理 · 物理学 2010-03-03 K. Boutsia , B. Leibundgut , D. Trevese , F. Vagnetti

How does the environment affect active galactic nucleus (AGN) activity? We investigated this question in an extinction-free way, by selecting 1120 infrared galaxies in the $AKARI$ North Ecliptic Pole Wide field at redshift $z$ $\leq$ 1.2. A…

We present a large sample of infrared-luminous candidate active galactic nuclei (AGNs) that lack X-ray detections in Chandra, XMM-Newton, and NuSTAR fields. We selected all optically detected SDSS sources with redshift measurements,…