Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.2
2.6
Journals
Universe
Special Issues
Supermassive Black Hole Mass Measurements
share announcement

Supermassive Black Hole Mass Measurements

A special issue of Universe (ISSN 2218-1997). This special issue belongs to the section "Compact Objects".

Deadline for manuscript submissions: 20 March 2026 | Viewed by 1735

Special Issue Editor

Dr. Benjamin Boizelle

E-Mail Website
Guest Editor
Department of Physics and Astronomy, Texas A&M University, College Station, TX, USA
Interests: supermassive black holes; mm/sub-mm astronomy; gas-dynamical modeling; active galactic nuclei; IR spectroscopy

Special Issue Information

Dear Colleagues,

Over the past 30 years, the masses of supermassive black holes (SMBHs) have been shown to correlate with certain properties of their host galaxies, indicating that they are crucial components in regulating galaxy growth across cosmic time. However, the current samples are insufficient for a detailed analysis of their co-evolution by galaxy type, environment, or as a function of redshift. The ever-increasing amount of samples of SMBH masses have been measured using a variety of techniques, including resolved stellar and gaseous kinematic tracers, the reverberation mapping (RM) of the accretion disk and broad-line region clouds in active galaxies, and the hydrostatic equilibrium modeling of hot halos. Now, higher-precision SMBH masses are enabled through advances in imaging technology, the identification of additional kinematics tracers, high-cadence monitoring and broad spectral coverage, and improvements in modeling, computational, and statistical approaches.

The present Special Issue aims to host several contributions dealing with SMBH mass measurements from the local universe to high redshifts. Potential topics include, but are not limited to, the following:

  • SMBH mass measurements using new or established techniques;
  • High-redshift studies of galaxy and SMBH growth using kinematics or line excitation;
  • SMBH growth over cosmic time, either through observations, R-L relationships, or simulations;
  • Cross-checks between different mass measurement techniques;
  • Kinematic studies that probe the SMBH sphere of influence;
  • RM or accretion disk studies that can provide information about SMBH masses;
  • The connection between an SMBH mass and the circumnuclear environment;
  • An analysis of the current samples to probe SMBH mass–host galaxy scaling relationships;
  • A review of the current state of SMBH mass measurements or the growth of SMBH masses during mergers.

Dr. Benjamin Boizelle
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Universe is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • supermassive black holes
  • active galactic nuclei
  • stellar or gaseous kinematics
  • dynamical modeling

Benefits of Publishing in a Special Issue

  • Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
  • Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
  • Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
  • External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
  • Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Published Papers (3 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

Jump to: Review

29 pages, 16778 KB  
Article
Detecting Intermediate-Mass Black Holes out to 20 Mpc with ELT/HARMONI: The Case of FCC 119
by Hai N. Ngo, Dieu D. Nguyen, Tinh T. Q. Le, Tien H. T. Ho, Truong N. Nguyen and Trung H. Dang
Universe 2025, 11(11), 360; https://doi.org/10.3390/universe11110360 - 31 Oct 2025
Viewed by 518
Abstract
Intermediate-mass black holes (IMBHs; MBH≈103–5 M⊙) play a critical role in understanding the formation of supermassive black holes in the early universe. In this study, we expand on Nguyen et al.’s simulated measurements of [...] Read more.
Intermediate-mass black holes (IMBHs; MBH≈103–5 M⊙) play a critical role in understanding the formation of supermassive black holes in the early universe. In this study, we expand on Nguyen et al.’s simulated measurements of IMBH masses using stellar kinematics, which will be observed with the High Angular Resolution Monolithic Optical and Near-infrared Integral (HARMONI) field spectrograph on the Extremely Large Telescope (ELT) up to a distance of 20 Mpc. Our sample focuses on both the Virgo Cluster in the northern sky and the Fornax Cluster in the southern sky. We begin by identifying dwarf galaxies hosting nuclear star clusters, which are thought to be nurseries for IMBHs in the local universe. As a case study, we conduct simulations for FCC 119, the second faintest dwarf galaxy in the Fornax Cluster at 20 Mpc, which is also fainter than most of the Virgo Cluster members. We use the galaxy’s surface brightness profile from Hubble Space Telescope (HST) imaging, combined with an assumed synthetic spectrum, to create mock observations with the HSIM simulator and Jeans Anisotropic Models (JAMs). These mock HARMONI data cubes are analyzed as if they were real observations, employing JAMs within a Bayesian framework to infer IMBH masses and their associated uncertainties. We find that ELT/HARMONI can detect the stellar kinematic signature of an IMBH and accurately measure its mass for MBH≳105M⊙ out to distances of ∼20 Mpc. Full article
(This article belongs to the Special Issue Supermassive Black Hole Mass Measurements)
►▼ Show Figures

Figure 1

13 pages, 793 KB  
Article
Red Noise Suppression in Pulsar Timing Array Data Using Adaptive Splines
by Yi-Qian Qian, Yan Wang and Soumya D. Mohanty
Universe 2025, 11(8), 268; https://doi.org/10.3390/universe11080268 - 15 Aug 2025
Viewed by 653
Abstract
Noise in Pulsar Timing Array (PTA) data is commonly modeled as a mixture of white and red noise components. While the former is related to the receivers, and easily characterized by three parameters (EFAC, EQUAD and ECORR), the latter arises from a mix [...] Read more.
Noise in Pulsar Timing Array (PTA) data is commonly modeled as a mixture of white and red noise components. While the former is related to the receivers, and easily characterized by three parameters (EFAC, EQUAD and ECORR), the latter arises from a mix of hard to model sources and, potentially, a stochastic gravitational wave background (GWB). Since their frequency ranges overlap, GWB search methods must model the non-GWB red noise component in PTA data explicitly, typically as a set of mutually independent Gaussian stationary processes having power-law power spectral densities. However, in searches for continuous wave (CW) signals from resolvable sources, the red noise is simply a component that must be filtered out, either explicitly or implicitly (via the definition of the matched filtering inner product). Due to the technical difficulties associated with irregular sampling, CW searches have generally used implicit filtering with the same power law model as GWB searches. This creates the data analysis burden of fitting the power-law parameters, which increase in number with the size of the PTA and hamper the scaling up of CW searches to large PTAs. Here, we present an explicit filtering approach that overcomes the technical issues associated with irregular sampling. The method uses adaptive splines, where the spline knots are included in the fitted model. Besides illustrating its application on real data, the effectiveness of this approach is investigated on synthetic data that has the same red noise characteristics as the NANOGrav 15-year dataset and contains a single non-evolving CW signal. Full article
(This article belongs to the Special Issue Supermassive Black Hole Mass Measurements)
►▼ Show Figures

Figure 1

Review

Jump to: Research

25 pages, 723 KB  
Review
Measuring Supermassive Black Hole Masses with H2O Megamasers: Observations, Methods, and Implications for Black Hole Demographics
by Cheng-Yu Kuo
Universe 2025, 11(12), 415; https://doi.org/10.3390/universe11120415 - 12 Dec 2025
Abstract
Measuring supermassive black hole (SMBH) masses is fundamental to understanding active
galactic nuclei (AGN) and their coevolution with host galaxies. Among existing techniques,
H2O megamaser observations with Very Long Baseline Interferometry (VLBI) provide the
most direct and geometric determinations of SMBH masses by [...] Read more.
Measuring supermassive black hole (SMBH) masses is fundamental to understanding active
galactic nuclei (AGN) and their coevolution with host galaxies. Among existing techniques,
H2O megamaser observations with Very Long Baseline Interferometry (VLBI) provide the
most direct and geometric determinations of SMBH masses by tracing molecular gas in
sub-parsec Keplerian disks. Over the past two decades, the Megamaser Cosmology Project
(MCP) has surveyed thousands of nearby AGNs and obtained high-sensitivity VLBI maps
of dozens of maser disks that lead to accurate SMBH masses with uncertainties typically
below 10%. In this paper, we present a comprehensive review that summarizes the essential
elements required to obtain accurate black hole masses with the H2O megamaser technique—
including the physical conditions for maser excitation, observational requirements,
disk modeling, and sources of SMBH mass uncertainty—and we discuss the implications of
maser-based measurements for exploring SMBH demographics. In particular, we will show
that maser-derived black hole masses, largely free from the systematic biases of stellar or
gas-dynamical methods, provide critical anchors at the low-mass end of the SMBH population
(MBH ∼ 107M⊙), and reveal possible deviations from the canonical MBH–σ∗ relation.
With forthcoming spectroscopic surveys and advances in millimeter/submillimeter VLBI,
the maser technique promises to extend precise dynamical mass measurements to both
larger local samples and high-redshift galaxies. Full article
(This article belongs to the Special Issue Supermassive Black Hole Mass Measurements)
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-3
Back to TopTop