English
Related papers

Related papers: A Chandra and HST View of WISE-Selected AGN Candid…

200 papers

Searching for active galactic nuclei (AGN) in dwarf galaxies is important for our understanding of the seed black holes that formed in the early Universe. Here, we test infrared selection methods for AGN activity at low galaxy masses. Our…

Astrophysics of Galaxies · Physics 2016-12-07 Kevin N. Hainline , Amy E. Reines , Jenny E. Greene , Daniel Stern

The ability to accurately discern active massive black holes (BHs) in nearby dwarf galaxies is paramount to understanding the origins and processes of "seed" BHs in the early Universe. We present Chandra X-ray Observatory observations of a…

Astrophysics of Galaxies · Physics 2024-09-10 Adonis A. Sanchez , Amy E. Reines , Akos Bogdan , Ralph P. Kraft

We investigate the possible presence of active galactic nuclei (AGN) in dwarf galaxies and other nearby galaxies to identify candidates for follow-up confirmation and dynamical mass measurements. We use the Wide-field Infrared Survey…

Astrophysics of Galaxies · Physics 2017-07-19 Francine R. Marleau , Dominic Clancy , Rebecca Habas , Matteo Bianconi

Effectively finding and identifying active galactic nuclei (AGNs) in dwarf galaxies is an important step in studying black hole formation and evolution. In this work, we examine four mid-IR-selected AGN candidates in dwarf galaxies with…

Astrophysics of Galaxies · Physics 2025-01-20 Megan R. Sturm , Bayli Hayes , Amy E. Reines

To investigate the population of massive black holes in dwarf galaxies, we conduct a systematic search for active galactic nuclei (AGNs) using data from the first data release of the eROSITA All-Sky Survey (eRASS1). We crossmatch dwarf…

Astrophysics of Galaxies · Physics 2025-09-30 John-Michael Eberhard , Amy E. Reines

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,…

We present new Chandra X-ray Observatory and Hubble Space Telescope observations of eight optically selected broad-line AGN candidates in nearby dwarf galaxies ($z<0.055$). Including archival Chandra observations of three additional…

High Energy Astrophysical Phenomena · Physics 2017-02-15 Vivienne F. Baldassare , Amy E. Reines , Elena Gallo , Jenny E. Greene

Dual active galactic nuclei (AGNs) and offset AGNs are kpc-scale separation supermassive black holes pairs created during galaxy mergers, where both or one of the black holes are AGNs, respectively. These dual and offset AGNs are valuable…

We present X-ray and optical analysis of 188 AGN identified from 497 hard X-ray (f (2.0-8.0 keV) > 2.7x10^-15 erg cm^-2 s^-1) sources in 20 Chandra fields (1.5 deg^2) forming part of the Chandra Multi-wavelength Project. These medium depth…

We searched in the public archive of the Chandra X-ray Observatory as of March 2016 and assembled a sample of 719 galaxies within 50 Mpc with ACIS observations available. By cross-correlation with the optical or near-infrared nuclei of…

Astrophysics of Galaxies · Physics 2017-02-08 Rui She , Luis C. Ho , Hua Feng

A large fraction of active galactic nuclei (AGN) are "invisible" in extant optical surveys due to either distance or dust-obscuration. The existence of this large population of dust-obscured, infrared-bright AGN is predicted by models of…

Astrophysics of Galaxies · Physics 2017-04-12 Alexandra Truebenbach , Jeremy Darling

Identifying AGNs in dwarf galaxies is critical for understanding black hole formation but remains challenging due to their low luminosities, low metallicities, and star formation-driven emission that can obscure AGN signatures. Machine…

We use Chandra data to study the incidence and properties of Active Galactic Nuclei (AGN) in 16 intermediate redshift ($0.5 < z < 1.1$) X-ray-selected galaxy groups in the Chandra Deep Field-South. We measure an AGN fraction of $f(L_{X,H} >…

We explore the presence of active galactic nuclei (AGN)/black holes (BH) in Green Pea galaxies (GPs), motivated by the presence of high ionization emission lines such as HeII and [NeIII] in their optical spectra. In order to identify AGN…

Astrophysics of Galaxies · Physics 2022-05-09 Santosh Harish , Sangeeta Malhotra , James E. Rhoads , Tianxing Jiang , Huan Yang , Kendrick Knorr

We present a multi-wavelength analysis of three candidate active galactic nuclei (AGNs) in low-mass galaxies in the Bo\"otes field with the aim of improving constraints on the occupation fraction of low-mass black holes (BHs). Galaxies with…

Astrophysics of Galaxies · Physics 2025-02-20 Rujuta A. Purohit , Ryan C. Hickox , Grayson C. Petter

The application of multi-wavelength selection techniques is crucial for discovering a complete and unbiased set of Active Galactic Nuclei (AGNs). Here, we select a sample of 72 AGN candidates in the Extended Groth Strip (EGS) using deep…

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…

Astrophysics of Galaxies · Physics 2022-04-27 Raphael E. Hviding , Kevin N. Hainline , Marcia Rieke , Stéphanie Juneau , Jianwei Lyu , Ragadeepika Pucha

Kiloparsec-scale binary active galactic nuclei (AGNs) signal active supermassive black hole (SMBH) pairs in merging galaxies. Despite their significance, unambiguously confirmed cases remain scarce and most have been discovered…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Xin Liu , Francesca Civano , Yue Shen , Paul J. Green , Jenny E. Greene , Michael A. Strauss

We analyze Hubble Space Telescope (HST) optical imaging of eight low-mass galaxies hosting active galactic nuclei (AGN) identified via their photometric variability in \cite{baldassare_search_2020}. We use GALFIT to model the 2D galaxy…

Astrophysics of Galaxies · Physics 2025-02-06 Erin Kimbro , Vivienne Baldassare , Guy Worthey , Marla Geha , Jenny Greene

We investigated AGN activity in low-mass galaxies, an important regime that can shed light onto BH formation and evolution, and their interaction with their host galaxies. We identified 336 AGN candidates from a parent sample of $\sim…

‹ Prev 1 2 3 10 Next ›