activity
20202026
most citedQuasars as standard candles III. Validation of a new sample for cosmological studies

176 citations · 331 across the 34 of their papers we have counts for

collaborators

35 papers

astro-ph.GA2026

Fooled by mass? Recovering the relation of quasars from their X-ray variability

Matilde Signorini, Andrea Sacchi, Bartolomeo Trefoloni +7

We measure the relation between the X-ray photon index and the Eddington ratio in unobscured type-1 quasars, using as parent sample the cross-match of the SDSS DR16Q…

astro-ph.HE2026

Observation of A Solar Like Magnetic Reconnection Event in an AGN Corona with XRISM

Gal Vardi, Ehud Behar, Liyi Gu +14

The X-ray source in AGN is commonly referred to as the corona by analogy to stellar coronae. The similarities between the two suggest that the heating mechanism of AGN coronae is m…

astro-ph.GA2026

Precision near-IR spectroscopy for understanding AGN physics and shed light on the H0 tension -- SHARP Science Book

M. Signorini, V. N. Bennert, E. Dalla Bontà +3

The persistent tension between early- and late-Universe measurements of the Hubble constant (H0) remains on of the most significant challenges in modern cosmology. The Spectroastro…

astro-ph.GA2026

No evolution in the number density of little red dots from cosmic dawn to cosmic noon

Federica Loiacono, Roberto Gilli, Marco Mignoli +24

We present our search for little red dots (LRDs) in the "J1030 field", a region of the sky around the quasar SDSS J1030+0524, observed by the JWST EIGER program. Over 1…

astro-ph.HE2026

The X-ray-to-UV relation does not evolve in homogeneous quasar samples

G. Risaliti, E. Lusso, E. Nardini +6

We present a new, highly homogeneous quasar sample with X-ray and UV observations optimized to reliably estimate distances via the non-linear X-ray-to-UV relation. Cross-matching t…

astro-ph.HE2026★ 1 cited

Delving into the depths of NGC 3783 with XRISM: V. Broad-band modeling of ionized outflows

Keqin Zhao, Jelle S. Kaastra, Liyi Gu +7

The Seyfert 1 galaxy NGC 3783 hosts a multiphase warm absorber (WA) that has been extensively studied in the X-ray band. High-resolution spectra from 2000-2001 revealed a complex o…

astro-ph.GA2026

Resolved UV-Optical HST Imaging and Spectral Energy Distribution Modeling of Nearby BAT Active Galactic Nuclei

Connor Auge, Michael Koss, Kriti K. Gupta +17

We use high-resolution UV-to-optical imaging from the Hubble Space Telescope (HST) to construct spatially resolved spectral energy distributions (SEDs) for seven nearby ()…

astro-ph.GA2026

BASS. LI. Cool gas supply of HI-massive local Seyfert galaxies

Jeein Kim, Aeree Chung, O. Ivy Wong +19

We present neutral atomic hydrogen (HI) imaging observations of 22 HI-rich (), hard X-ray-selected local Seyferts to explore how cool gas is su…

astro-ph.GA2026

Radio selection of heavily obscured AGN in the J1030 field: unraveling a missing Compton-thick population

Giovanni Mazzolari, Roberto Gilli, Marco Mignoli +21

We tested the effectiveness of radio selection to discover heavily obscured AGNs, particularly at high-z, and we measured their abundance for the first time from a radio perspectiv…

astro-ph.GA2026★ 1 cited

The X-ray properties of the most luminous quasars with strong emission-line outflows

Anastasia Shlentsova, Bartolomeo Trefoloni, Matilde Signorini +7

Strong outflows from active galactic nuclei are frequently observed in objects with lower coronal X-ray luminosity. This intrinsic X-ray weakness is considered a requirement for th…

astro-ph.GA2026

BASS LV. Connecting X-ray variability with AGN physical properties and a new path to Cosmological distances

Matilde Signorini, Federica Ricci, Alessia Tortosa +18

X-ray variability is a well-established characteristic of active galactic nuclei (AGN), known to correlate inversely with both the supermassive black hole mass and luminosity, alth…

astro-ph.GA2025

The accretion of quasars at the epoch of reionisation: catches the primeval monsters slowly feasting

B. Trefoloni, E. Nardini, S. Carniani +8

Quasars (QSOs) emit an enormous amount of light as a result of the accretion of gas onto supermassive black holes (SMBHs). Thanks to their luminosity, the most distant known QSOs a…

astro-ph.HE2025★ 10 cited

Delving into the depths of NGC 3783 with XRISM IV. Mapping of the accretion flow with Fe K emission lines

Chen Li, Jelle S. Kaastra, Liyi Gu +18

Using XRISM/Resolve time-averaged spectra of the well-known Seyfert-1.5 active galactic nucleus (AGN) in NGC 3783, we investigate the nature of the Fe K emission…

astro-ph.HE2025★ 10 cited

Delving into the depths of NGC 3783 with XRISM III. Birth of an ultrafast outflow during a soft flare

Liyi Gu, Keigo Fukumura, Jelle Kaastra +18

The 2024 X-ray/UV observation campaign of NGC 3783, led by XRISM, revealed the launch of an ultrafast outflow (UFO) with a radial velocity of 0.19c (57000 km/s). This event is sync…

astro-ph.HE2025★ 3 cited

The Advanced X-ray Imaging Satellite (AXIS) Community Science Book

Michael Koss, Nafisa Aftab, Steven W. Allen +395

The AXIS Community Science Book represents the collective effort of 592 scientists worldwide to define the transformative science enabled by the Advanced X-ray Imaging Satellite (A…

astro-ph.GA2025

BASS LIV. Physical Properties of AGN-Hosting Galaxy Mergers from Multiwavelength SED Fitting

Marco Troncoso, Ezequiel Treister, Alejandra Rojas +17

Galaxy mergers are believed to play an important role in triggering rapid supermassive black hole (SMBH) growth. As merging nuclei approach each other, the physical properties of t…

astro-ph.HE2025★ 1 cited

The X-rayUV Luminosity Relation of eROSITA Quasars

Andrea Sacchi, Guido Risaliti, Matilde Signorini +3

The non-linear relation between the UV and X-ray luminosity in quasars has been studied for decades. However, as we lack a comprehensive model able to explain it, its investigation…

astro-ph.GA2025★ 8 cited

BASS. XLIX. Characterization of highly luminous and obscured AGNs: local X-ray and [NeV]3426 emission in comparison with the high-redshift Universe

Alessandro Peca, Michael J. Koss, Kyuseok Oh +21

We present a detailed analysis of the most luminous and obscured Active Galactic Nuclei (AGNs) detected in the ultra-hard X-ray band (14-195 keV) by Swift/BAT. Our sample comprises…

astro-ph.GA2025★ 1 cited

AGN with massive black holes have closer galactic neighbors: k-Nearest-Neighbor statistics of an unbiased sample of AGN at z~0.03

A. Mhatre, M. C. Powell, S. Yuan +10

The large-scale environments of active galactic nuclei (AGN) reveal important information on the growth and evolution of supermassive black holes (SMBHs). Previous AGN clustering m…

astro-ph.GA2025★ 10 cited

A big red dot at cosmic noon

Federica Loiacono, Roberto Gilli, Marco Mignoli +22

We report the discovery of a little red dot (LRD), dubbed BiRD ('big red dot'), at in the field around the quasar SDSSJ1030+0524. Using NIRCam images, we identifie…

astro-ph.GA2024★ 18 cited

The radio properties of the JWST-discovered AGN

G. Mazzolari, R. Gilli, R. Maiolino +23

We explore the radio emission of JWST-selected Broad Line AGN (BLAGN, or type 1) in the GOODS-N field. We use deep radio data at different frequencies (144\,MHz, 1.5\,GHz, 3\,GHz,…

astro-ph.GA2024★ 6 cited

The near-infrared SED of blue quasars: what drives the evolution of the dusty torus?

Bartolomeo Trefoloni, Roberto Gilli, Elisabeta Lusso +5

A fundamental ingredient in the unified model of active galactic nuclei (AGN) is the obscuring torus, whose innermost, hottest region dominates the near infrared (NIR) emission. Ch…

astro-ph.HE2024

AGN STORM 2: IX. Studying the Dynamics of the Ionized Obscurer in Mrk 817 with High-resolution X-ray Spectroscopy

Fatima Zaidouni, Erin Kara, Peter Kosec +45

We present the results of the XMM-Newton and NuSTAR observations taken as part of the ongoing, intensive multi-wavelength monitoring program of the Seyfert 1 galaxy Mrk 817 by the…

astro-ph.GA2024★ 9 cited

JWST meets Chandra: a large population of Compton thick, feedback-free, and intrinsically X-ray weak AGN, with a sprinkle of SNe

Roberto Maiolino, Guido Risaliti, Matilde Signorini +22

We investigate the X-ray properties of a sample of 71 broad line and narrow line AGN at 2z11 discovered by JWST in the GOODS fields, which have the deepest Chandra observatio…