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Related papers: Mid-infrared Variability-based AGN Selection using…

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The Wide-field Infrared Survey Explorer (WISE) has scanned the entire sky with unprecedented sensitivity in four infrared bands, at 3.4, 4.6, 12, and 22 micron. The WISE Point Source Catalog contains more than 560 million objects, among…

Astrophysics of Galaxies · Physics 2015-06-18 Robert Nikutta , Maia Nenkova , Zeljko Ivezic , Nicholas Hunt-Walker , Moshe Elitzur

We present an X-ray analysis of fourteen nearby (z < 0.044) AGN in low mass galaxies (M_* <= 5*10^9 Msun) selected based on their optical variability (Baldassare et al. 2020). Comparing and contrasting different AGN selection techniques in…

Astrophysics of Galaxies · Physics 2023-08-09 Alexander Messick , Vivienne Baldassare , Marla Geha , Jenny Greene

Temporal asymmetry in the flux variability of active galactic nuclei (AGNs) offers key insights into the physical mechanisms driving AGN variability. In this study, we investigated the variability of the torus by analyzing temporal…

Astrophysics of Galaxies · Physics 2026-01-05 Suyeon Son , Minjin Kim , Luis C. Ho

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

Past studies of compact active galactic nuclei (AGNs), the dominant population at high radio frequencies, selected them using flat spectral index criteria. This biases the sample due to the steepening of AGN spectra at high radio…

Astrophysics of Galaxies · Physics 2020-03-04 R. Chhetri , A. Kimball , R. D. Ekers , E. K. Mahony , E. M. Sadler , T. Jarrett

We identify a population of 640 obscured and 839 unobscured AGNs at redshifts 0.7<z<~3 using multiwavelength observations of the 9 deg^2 NOAO Deep Wide-Field Survey (NDWFS) region in Bootes. We select AGNs on the basis of Spitzer IRAC…

The combination of optical and mid-infrared (MIR) photometry has been extensively used to select red active galactic nuclei (AGNs). Our aim is to explore the obscuration properties of these red AGNs with both X-ray spectroscopy and spectral…

Context. A defining characteristic of active galactic nuclei (AGN) that distinguishes them from other astronomical sources is their stochastic variability, which is observable across the entire electromagnetic spectrum. Upcoming optical…

The identification of AGN in large surveys has been hampered by seemingly discordant classifications arising from differing diagnostic methods, usually tracing distinct processes specific to a particular wavelength regime. However, as shown…

Using a new color-color diagnostic diagram in the mid infrared built from WISE data, the MIRDD, we compare narrow emission-line galaxies (NELGs) that exhibit different activity types (star-forming galaxies, SFGs, and AGNs, i.e.,LINERs, Sy2s…

Astrophysics of Galaxies · Physics 2015-05-27 R. Coziol , J. P. Torres-Papaqui , H. Andernach

We present a systematic analysis of the mid-infrared (MIR) properties of the youngest radio galaxies, based on low-resolution data provided by the {\it WISE} and {\it IRAS} satellites. We restrict our analysis to sources with available…

High Energy Astrophysical Phenomena · Physics 2020-07-22 E. Kosmaczewski , L. Stawarz , A. Siemiginowska , C. C. Cheung , L. Ostorero , M. Sobolewska , D. Koziel-Wierzbowska , A. Wojtowicz , V. Marchenko

We study the optical variability of a sample of candidate low-mass (dwarf ang Seyfert) active galactic nuclei (AGNs) using Zwicky Transient Facility g-band light curves. Our sample is compiled from broad-line AGNs in dwarf galaxies reported…

Astrophysics of Galaxies · Physics 2023-04-11 Z. Franklin Wang , Colin J. Burke , Xin Liu , Yue Shen

Dust reprocesses the intrinsic radiation of active galactic nuclei (AGNs) to emerge at longer wavelengths. The observed mid-infrared (MIR) luminosity depends fundamentally on the luminosity of the central engine, but in detail it also…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 N. A. Levenson , J. T. Radomski , C. Packham , R. E. Mason , J. J. Schaefer , C. M. Telesco

We present the results of a study of different statistical methods currently used in the literature to analyse the (micro)variability of active galactic nuclei (AGNs) from ground-based optical observations. In particular, we focus on the…

Astrophysics of Galaxies · Physics 2017-02-16 L. Zibecchi , I. Andruchow , S. A. Cellone , D. D. Carpintero , G. E. Romero , J. A. Combi

AIMS. This work addresses the AGN IR-selection dependency on intrinsic source luminosity and obscuration, in order to identify and charaterise biases which could affect conclusions in studies. METHODS. We study IR-selected AGN in the…

Astrophysics of Galaxies · Physics 2015-06-18 Hugo Messias , Jose M. Afonso , Mara Salvato , Bahram Mobasher , Andrew M. Hopkins

Most tidal disruption events (TDEs) are currently found in time-domain optical and soft X-ray surveys, both of which are prone to significant obscuration. The infrared (IR), however, is a powerful probe of dust-enshrouded environments, and…

In order to answer some of the major open questions in the fields of supermassive black hole (SMBH) and galaxy evolution, a complete census of SMBH growth, i.e., active galactic nuclei (AGN), is required. Thanks to deep all-sky surveys,…

We assemble a sample of 733 dwarf galaxies ($M_{\ast} \le 10^{9.5} \text{M}_\odot$) with signatures of active galactic nuclei (AGN) and explore the intersection between different AGN selection techniques. Objects in our database are…

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

We study the mid- to far-IR properties of a 24um-selected flux-limited sample (S24 > 5mJy) of 154 intermediate redshift (<z>~0.15), infrared luminous galaxies, drawn from the 5MUSES survey. By combining existing mid-IR spectroscopy and new…

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…

Astrophysics of Galaxies · Physics 2025-05-06 Tran Tsan , Matthew Malkan , Rick Edelson , Krista Smith , Daniel Stern , Matthew Graham