Related papers: Identification and Characterization of a Large Sam…
Deep surveys of the cosmic X-ray background are reviewed in the context of observational progress enabled by the Chandra X-ray Observatory and the X-ray Multi-Mirror Mission-Newton. The sources found by deep surveys are described along with…
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…
We perform X-ray spectral analyses to derive characteristics (e.g., column density, X-ray luminosity) of $\approx$10,200 active galactic nuclei (AGNs) in the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS), which was…
We report the multi-wavelength identification of the X-ray sources found in the Subaru-XMM-Newton Deep Survey (SXDS) using deep imaging data covering the wavelength range between the far-UV to the mid-IR. We select a primary counterpart of…
We present a sample of accreting supermassive black holes (SMBHs) in dwarf galaxies at $z<1$. We identify dwarf galaxies in the NEWFIRM Medium Band Survey with stellar masses $M_{\star}<3\times 10^{9} M_{\odot}$ that have spectroscopic…
We present a sample of 99 dwarf galaxies ($M_*<10^{9.5} M_\odot$) with X-ray activity in their central regions. The sample was obtained from a match of the SRG/eROSITA X-ray catalogue in the Eastern Galactic hemisphere with the MPA-JHU SDSS…
In this work we present a robust quantification of X-ray selected AGN in local ($z \leq 0.25$) dwarf galaxies ($M_\mathrm{*} \leq 3 \times 10^9 \mathrm{M_\odot}$). We define a parent sample of 4,331 dwarf galaxies found within the footprint…
X-rays provide a robust method in identifying AGN. However, in the high-redshift Universe, their space density is relatively low, and, in combination with the small areas covered by X-ray surveys, the selected AGN are poorly sampled. Deep…
Determining the fraction of nearby dwarf galaxies hosting massive black holes (BHs) can inform our understanding of the origin of "seed" black holes at high redshift. Here we search for signatures of accreting massive BHs in a sample of…
In this work, we use 8 years of deep near-infrared imaging to select and study a new set of 601 active galaxies identified through long-term near-infrared (NIR) variability in the UKIDSS Ultra Deep Survey (UDS). These objects are compared…
The $\gamma$-ray emission from active galactic nuclei (AGN), including both beamed blazars and misaligned-AGN, dominates the extragalactic $\gamma$-ray point-source population count and flux. While multi-wavelength studies have detected an…
X-ray extragalactic surveys are ideal laboratories for the study of the evolution and clustering of active galactic nuclei (AGN). The XXL Survey spans two fields of a combined 50 $deg^2$ observed for more than 6Ms with XMM-Newton, occupying…
A fundamental question in galaxy and black-hole evolution remains how galaxies and their supermassive black holes have evolved together over cosmic time. Specifically, it is still unclear how the position of X-ray active galactic nucleus…
While theory and simulations indicate that galaxy mergers play an important role in the cosmological evolution of accreting black holes and their host galaxies, samples of Active Galactic Nuclei (AGN) in galaxies at close separations are…
We review results from cosmic X-ray surveys of active galactic nuclei (AGNs) over the past ~ 15 yr that have dramatically improved our understanding of growing supermassive black holes in the distant universe. First, we discuss the utility…
The low-mass end of low-mass galaxies is largely unexplored in AGN studies, but it is essential for extending our understanding of the black hole-galaxy coevolution. We surveyed the 3D-HST catalog and collected a sample of 546 dwarf…
X-rays offer a reliable method to identify Active Galactic Nuclei (AGN). However, in the high-redshift Universe X-ray AGN are poorly sampled due to their relatively low space density and the small areas covered by X-ray surveys. In addition…
In order to understand the interactions between active galactic nuclei (AGN) and star formation during the evolution of galaxies, we investigate 142 galaxies detected in both X-ray and 70{\mu}m observations in the COSMOS (Cosmic Evolution…
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…
This paper presents a survey of X-ray selected active galactic nuclei (AGN) with optical spectroscopic follow-up in a $\sim 18\, \rm{deg^2}$ area of the equatorial XMM-XXL north field. A sample of 8445 point-like X-ray sources detected by…