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Related papers: A versatile classification tool for galactic activ…

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We searched the Northern Hemisphere Fields of the GALEX Time-Domain Survey (TDS) for galaxies with UV variability indicative of active galactic nuclei (AGNs). We identified 48 high-probability candidate AGNs from a parent sample of 1819…

Astrophysics of Galaxies · Physics 2024-05-31 Erik J. Wasleske , Vivienne F. Baldassare , Christopher M. Carroll

We present a study of the connection between black hole accretion, star formation, and galaxy morphology at z<=2.5. We focus on active galactic nuclei (AGNs) selected by their mid-IR power-law emission. By fitting optical to far-IR…

We combine data from two all-sky surveys in order to study the connection between the infrared and hard X-ray (>10keV) properties for local active galactic nuclei (AGN). The Swift/Burst Alert Telescope all-sky survey provides an unbiased,…

A large body of evidence has demonstrated that the global rest-frame optical and IR colours of galaxies correlate well with each other, as well as with other galactic properties such as surface brightness and morphology. However the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Stefano Zibetti , Brent Groves

We present the unWISE Catalog, containing the positions and fluxes of roughly two billion objects observed by the Wide-field Infrared Survey Explorer (WISE) over the full sky. The unWISE Catalog has two advantages over the existing WISE…

Instrumentation and Methods for Astrophysics · Physics 2019-02-13 Edward F. Schlafly , Aaron M. Meisner , Gregory M. Green

We present a study of Spitzer/IRAC and X-ray active galactic nuclei (AGNs) selection techniques in order to quantify the overlap, uniqueness, contamination, and completeness of each. We investigate how the overlap and possible contamination…

Classifying catalog objects as stars, galaxies, or AGN is a crucial part of any statistical study of galaxies. We describe our pipeline for binary (star/galaxy) and multiclass (star/galaxy/Type I AGN/Type II AGN) classification developed…

Astrophysics of Galaxies · Physics 2021-04-14 Anneya Golob , Marcin Sawicki , Andy D. Goulding , Jean Coupon

(Abridged) Many classes of active galactic nuclei (AGN) have been defined entirely throughout optical wavelengths while the X-ray spectra have been very useful to investigate their inner regions. However, optical and X-ray results show many…

We conduct for the first time a theoretical investigation of the mid-infrared spectral energy distribution (SED) produced by dust heated by an active galactic nucleus (AGN) and an extreme starburst. These models employ an integrated…

Astrophysics of Galaxies · Physics 2018-05-16 Shobita Satyapal , Nicholas P. Abel , Nathan J. Secrest

We present a 5-8 micron analysis of the Spitzer-IRS spectra of 71 ultraluminous infrared galaxies (ULIRGs) with redshift z < 0.15, devoted to the study of the role of active galactic nuclei (AGN) and starbursts (SB) as the power source of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 E. Nardini , G. Risaliti , M. Salvati , E. Sani , Y. Watabe , A. Marconi , R. Maiolino

We uniformly analyze 136 optically detected PNe and candidates from the GLIMPSE-I survey in order to to develop robust, multi-wavelength, classification criteria to augment existing diagnostics and provide pure PN samples. PNe represent…

Astrophysics of Galaxies · Physics 2015-05-20 Martin Cohen , Quentin A. Parker , Anne J. Green , Brent Miszalski , David J. Frew , Tara Murphy

We introduce a novel galaxy classification methodology based on the visible spectra of a sample of over 68,000 nearby ($z\leq 0.1$) Sloan Digital Sky Survey lenticular (S0) galaxies. Unlike traditional diagnostic diagrams, which rely on a…

Astrophysics of Galaxies · Physics 2025-01-10 J. L. Tous , J. M. Solanes , J. D. Perea

We have used a combination of stellar population synthesis and photoionization models to develop a set of ionization parameter and abundance diagnostics based only on the use of the strong optical emission lines. These models are applicable…

Astrophysics · Physics 2008-11-26 L. J. Kewley , M. A. Dopita

We study the narrow emission line properties and stellar populations of a sample of 1385 AGN selected to have strong excess emission at mid-infrared wavelengths based on comparing Wide-field Infrared Survey Explorer W1-W2 band colours with…

Astrophysics of Galaxies · Physics 2018-08-15 Guinevere Kauffmann

Optical emission-line diagnostic diagrams, such as the classical BPT, are widely used to identify ionisation mechanisms in galaxies but often suffer from degeneracies, especially when multiple sources coexist. We critically evaluate the…

Astrophysics of Galaxies · Physics 2026-01-14 S. F. Sánchez , C. Muñoz-Tuñón , J. Sánchez Almeida , O. González-Martín , E. Pérez

The Spitzer Space Telescope is pushing into new frontiers in high redshift astronomy. Closer to home, Spitzer is making an equally large impact on our understanding of galaxy formation and evolution. In this contribution we present…

Astrophysics · Physics 2007-05-23 Daniel A. Dale , the SINGS Team

We present the results of an optical spectroscopic survey of 46 heavily obscured quasar candidates. Objects are selected using their mid-infrared (mid-IR) colours and magnitudes from the Wide-Field Infrared Survey Explorer (WISE) and their…

Astrophysics of Galaxies · Physics 2017-12-27 R. E. Hviding , R. C. Hickox , K. N. Hainline , C. M. Carroll , M. A. DiPompeo , W. Yan , M. L. Jones

We report on the results of an optical spectroscopic survey at high Galactic latitude (b\geq30{\deg}) of a sample of WISE-selected targets, grouped by WISE W1 ({\lambda}_eff = 3.4 \mum) flux, which we use to characterize the sources WISE…

We describe a methodology to classify periodic variable stars identified using photometric time-series measurements constructed from the Wide-field Infrared Survey Explorer (WISE) full-mission single-exposure Source Databases. This will…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Frank J. Masci , Douglas I. Hoffman , Carl J. Grillmair , Roc M. Cutri

We use data from the All Wavelength Extended Groth Strip International Survey to construct stacked X-ray maps of optically bright active galaxies (AGN) and an associated control sample of galaxies at high redshift (z less than 0.6). From…

Astrophysics of Galaxies · Physics 2019-02-11 Sagnick Mukherjee , Anirban Bhattacharjee , Suchetana Chatterjee , Jeffrey A. Newman , Renbin Yan