Joint ALMA/X-ray monitoring of the radio-quiet type 1 active galactic nucleus IC 4329A
Artikel i vetenskaplig tidskrift, 2024

The origin of a compact millimeter (mm, 100-250 GHz) emission in radio-quiet active galactic nuclei (RQ AGN) remains debated. Recent studies propose a connection with self-Absorbed synchrotron emission from the accretion disk X-ray corona. We present the first joint ALMA (100 GHz) and X-ray (NICER/XMM-Newton/Swift; 2-10 keV) observations of the unobscured RQ AGN, IC 4329A (z = 0.016). The time-Averaged mm-To-X-ray flux ratio aligns with recently established trends for larger samples, but with a tighter scatter (∼0.1 dex) compared to previous studies. However, there is no significant correlation on timescales of less than 20 days. The compact mm emission exhibits a spectral index of-0.23 ± 0.18, remains unresolved with a 13 pc upper limit, and shows no jet signatures. Notably, the mm flux density varies significantly (by factor of 3) within four days, exceeding the contemporaneous X-ray variability and showing the largest mm variations ever detected in RQ AGN over daily timescales. The high amplitude variability rules out scenarios of heated dust and thermal free-free emission, pointing toward a synchrotron origin for the mm radiation in a source of ∼1 light day (∼120 gravitational radii) size. While the exact source is not yet certain, an X-ray corona scenario emerges as the most plausible compared to a scaled-down jet or outflow-driven shocks.

X-rays: galaxies

Galaxies: individual: IC 4329A

Submillimeter: galaxies

Författare

E. Shablovinskaya

Universidad Diego Portales

C. Ricci

Universidad Diego Portales

Beijing University of Technology

Chin Shin Chang

Atacama Large Millimeter-submillimeter Array (ALMA)

A. Tortosa

Osservatorio Astronomico di Roma

Santiago Del Palacio

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

Taiki Kawamuro

RIKEN

Susanne Aalto

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

Z. Arzoumanian

National Aeronautics and Space Administration (NASA)

Mislav Baloković

Yale University

F. E. Bauer

Pontificia Universidad Catolica de Chile

Space Science Institute

Instituto Milenio de Astrofísica

K. C. Gendreau

National Aeronautics and Space Administration (NASA)

Luis C. Ho

Beijing University of Technology

D. Kakkad

Space Telescope Science Institute (STScI)

E. Kara

Massachusetts Institute of Technology (MIT)

Michael J. Koss

Space Science Institute

Eureka Scientific

T. Liu

West Virginia University

M. Loewenstein

National Aeronautics and Space Administration (NASA)

College of Computer, Mathematical, & Natural Sciences

Richard Mushotzky

University of Maryland

College of Computer, Mathematical, & Natural Sciences

S. Paltani

Université de Genève

G. Privon

College of Liberal Arts and Sciences

University of Virginia

National Radio Astronomy Observatory

Krista L. Smith

Southern Methodist University

Texas A&M University

Francesco Tombesi

Istituto Nazionale di Fisica Nucleare

Osservatorio Astronomico di Roma

Universita degli Studi di Roma Tor Vergata

Benny Trakhtenbrot

Tel Aviv University

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 690 A232

Exploring the Hidden Dusty Nuclei of Galaxies (HIDDeN)

Europeiska forskningsrådet (ERC) (789410), 2018-10-01 -- 2023-09-30.

Ämneskategorier (SSIF 2011)

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik

DOI

10.1051/0004-6361/202450133

Mer information

Senast uppdaterat

2025-03-09