papers

Publications (29)

astro-ph.HE2026

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.GA2023

The most luminous blue quasars at 3.0<z<3.3 -- III. LBT spectra and accretion parameters

Bartolomeo Trefoloni, Elisabeta Lusso, Emanuele Nardini +13

We present the analysis of the rest frame ultraviolet and optical spectra of 30 bright blue quasars at , selected to examine the suitability of AGN as cosmological probes.…

astro-ph.HE2023

AGN STORM 2. VI. Mapping Temperature Fluctuations in the Accretion Disk of Mrk 817

Jack M. M. Neustadt, Christopher S. Kochanek, John Montano +49

We fit the UV/optical lightcurves of the Seyfert 1 galaxy Mrk 817 to produce maps of the accretion disk temperature fluctuations resolved in time and radius. The maps a…

astro-ph.HE2025

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 emissio…

astro-ph.GA2024

Quasars as standard candles VI: spectroscopic validation of the cosmological sample

Bartolomeo Trefoloni, Elisabeta Lusso, Emanuele Nardini +5

A sample of quasars has been recently assembled to investigate the non-linear relation between their monochromatic luminosities at 2500Ã , and 2 keV and to exploit quasars as a new…

astro-ph.HE2023

X-ray properties and obscured fraction of AGN in the J1030 Chandra field

Matilde Signorini, Stefano Marchesi, Roberto Gilli +13

The 500ks Chandra ACIS-I observation of the field around the quasar SDSS J1030+0524 is currently the 5th deepest extragalactic X-ray survey. The rich multi-band coverage o…

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.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

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.HE2026

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.CO2023

Quasars as Standard Candles IV. Analysis of the X-ray and UV indicators of the disc-corona relation

Matilde Signorini, Guido Risaliti, Elisabeta Lusso +4

Context: A non-linear relation between quasar monochromatic luminosities at 2500A and 2 keV holds at all observed redshifts and luminosities, and it has been used to derive quasar…

astro-ph.GA2024

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.CO2023

Quasars as Standard Candles V. Evaluation of a 0.06 dex intrinsic dispersion in the LX-LUV relation

Matilde Signorini, Guido Risaliti, Elisabeta Lusso +4

A characteristic feature of quasars is the observed non-linear relationship between their monochromatic luminosities at rest-frame 2500 Ã and 2 keV. This relationship is evident ac…

astro-ph.GA2023

LBT-MODS spectroscopy of high-redshift candidates in the Chandra J1030 field. A newly discovered z2.8 large scale structure

Stefano Marchesi, Marco Mignoli, Roberto Gilli +13

We present the results of a spectroscopic campaign with the Multi-Object Double Spectrograph (MODS) instrument mounted on the Large Binocular Telescope (LBT), aimed at obtaining a…

astro-ph.GA2021

The most luminous blue quasars at 3.0<z<3.3. II. CIV/X-ray emission and accretion disc physics

Elisabeta Lusso, Emanuele Nardini, Susanna Bisogni +12

We analyse the properties of the CIV broad emission line in connection with the X-ray emission of 30 bright SDSS quasars at z~3.0-3.3 with pointed XMM-Newton observations, which we…

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

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.CO2024

Building the high-redshift Hubble Diagram with quasars

Matilde Signorini, Guido Risaliti, Andrea Sacchi +2

Proceeding of the "HACK100" Conference, 6-10 June 2022, Trieste, Italy - In recent years, quasars have been shown to be reliable standardizable candles, thanks to the non-linear re…

astro-ph.GA2025

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.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

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

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…

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.CO2023

Quasars as high-redshift standard candles

Guido Risaliti, Elisabeta Lusso, Emanuele Nardini +5

In the past few years, we built a Hubble diagram of quasars up to redshift z7, based on the nonlinear relation between quasars' x-ray and UV luminosities. Such a Hubble diagr…

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 authors present the first direct observation of a magnetic reconnection flare in the X‑ray corona of the active galaxy NGC 3783, using XRISM and XMM‑Newton data that reveal a N…

#active galactic nuclei#magnetic reconnection#coronal flares#ultra-fast outflows
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.CO2023

Non-parametric analysis of the Hubble Diagram with Neural Networks

Lorenzo Giambagli, Duccio Fanelli, Guido Risaliti +1

The recent extension of the Hubble diagram of Supernovae and quasars to redshifts much higher than 1 prompted a revived interest in non-parametric approaches to test cosmological m…

astro-ph.GA2026

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.HE2025

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…