In this talk, I will present a review of the different machine learning (ML) techniques used to select and classify active galactic nuclei (AGNs) in large photometric surveys, such as the Zwicky Transient Facility (ZTF), Pan-STARRS, La Silla QUEST survey (LSQ), and the upcoming Rubin Observatory Legacy Survey of Space and Time (LSST). I will first introduce the most popular ML selection...
The upcoming Rubin/LSST survey will uncover millions of previously unknown AGN. However, due to the massive amount of data collected each night, it is essential to develop reliable tools that can efficiently identify quasars among billions of stars and inactive galaxies.
I will discuss the results of different machine-learning based selection algorithms, including probabilistic random...
We explore the use of machine learning for AGN selection from data
akin to the anticipated LSST survey (e.g., Savic et al. 2023). The
data is gathered from the AGN Data Challenge which comprises of two
primary sources: SDSS Stripe 82 and XMM-LSS. We also utilize data from
the DECam Local Volume Exploratoration Survey (DELVE). We employ
unsupervised clustering techniques, distinguishing...
We have started an exploratory project aimed at assessing the nature of high redshift radio galaxies (HzRGs) candidates for the next upcoming of Rubin-LSST survey. Powerful radio-loud AGNs represent the most extreme manifestation of nuclear activity and play a pivotal role in galaxy evolution. The epoch at z~4 is essential for studying the processes that connect supermassive black holes with...
Observations and models indicate that the fraction of active galaxies
in the local Universe is about 10% . As most large galaxies host a
supermassive black hole (SMBH), this can be interpreted as a duty
cycle, where 10% of galaxies are active at any given time. Estimating
this activation rate is important to constrain central black hole
feeding mechanisms in galaxy evolution models. Black...
The Vera C. Rubin Observatory is poised to generate an unparalleled dataset in terms of depth and sky coverage through its Legacy Survey of Space and Time (LSST). Understanding the selection criteria and biases for active galactic nuclei (AGNs) within such a dataset is crucial as the Rubin Observatory commences sciences operations. In this study, we investigate conventional broadband optical...
The interaction of galaxies play an important role in fueling the SMBHs and accelerating their growth. In this presentation, I will first introduce the techniques that we have used to identify mergers in HSC images, namely, the morphological asymmetry parameter. With over 2400 type 1 quasars between 0.2<z<0.8, we found that only the brightest quasars (log L_bol>44.5 erg/s) have an excess of...
