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Related papers: A New Method for Measuring Extragalactic Distances

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In this paper, we propose a new approach to determining cosmological distances to active galactic nuclei (AGN) via light travel-time arguments, which can be extended from nearby sources to very high redshift sources. The key assumption is…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Jeffrey A. Hodgson , Benjamin L'Huillier , Ioannis Liodakis , Sang-Sung Lee , Arman Shafieloo

The improvement of the calibration relation for determining the size of the broad-line region from the observed optical luminosity of active galactic nuclei (AGN) is a necessary task to study fundamental parameters of distant AGNs such as…

The dust reverberation mapping is one of powerful methods to investigate the structure of the dusty tori in AGNs, and it has been performed on more than a hundred type 1 AGNs. However, no clear results have been reported on type 2 AGNs…

Astrophysics of Galaxies · Physics 2020-05-27 Hirofumi Noda , Taiki Kawamuro , Mitsuru Kokubo , Takeo Minezaki

Distances to AGB stars with optically thick circumstellar shells cannot be determined using optical parallaxes. However, for stars with OH 1612 MHz maser emission emanating from their circumstellar shells, distances can be determined by the…

Solar and Stellar Astrophysics · Physics 2015-03-17 D. Engels , S. Etoka , E. Gerard , A. Richards

With the advancement of technology, machine learning-based analytical methods have pervaded nearly every discipline in modern studies. Particularly, a number of methods have been employed to estimate the redshift of gamma-ray loud active…

High Energy Astrophysical Phenomena · Physics 2023-12-13 Sarvesh Gharat , Abhimanyu Borthakur , Gopal Bhatta

Light-travel-time delays provide one of the most powerful ways of learning about the structure and kinematics of active galactic nuclei (AGNs). Estimating delays from observations of AGN variability presents statistical challenges because…

Astrophysics of Galaxies · Physics 2025-01-23 C. Martin Gaskell

Large scale outflows of different gas phases are ubiquitous in the host galaxies of active galactic nuclei (AGN). Despite their many differences, they share a common property - they all contain dust. The dust is carried with the outflow,…

Astrophysics of Galaxies · Physics 2018-11-07 Dalya Baron , Hagai Netzer

This is the third in a series of papers reporting on a large reverberation-mapping campaign aimed to study the properties of active galactic nuclei (AGNs) with high accretion rates. We present new results on the variability of the optical…

Astrophysics of Galaxies · Physics 2015-05-27 Chen Hu , Pu Du , Kai-Xing Lu , Yan-Rong Li , Fang Wang , Jie Qiu , Jin-Ming Bai , Shai Kaspi , Luis C. Ho , Hagai Netzer , Jian-Min Wang

We introduce a new infrared diagnostic to separate galaxies on the basis of their dominant infrared emission: stellar or nuclear. The main novelty with respect to existing diagnostics, is the usage of a broad band encompassing at the same…

Astrophysics of Galaxies · Physics 2015-06-22 Dario Fadda , Giulia Rodighiero

We combine multiwavelength data in the AEGIS-XD and C-COSMOS surveys to measure the typical dark matter halo mass of X-ray selected AGN [Lx(2-10keV)>1e42 erg/s] in comparison with far-infrared selected star-forming galaxies detected in the…

The discrepancy of the Hubble parameter H0 as measured from the cosmic microwave background versus that found from traditional distance ladder measurements has produced considerable discussion about the need for another force in cosmology.…

Active galactic nuclei (AGN) are high luminosity sources powered by accretion of matter onto SMBHs located at the centres of galaxies. The SMBH is surrounded by a broad emission line region (BLR) and a dusty torus. It is difficult to study…

Astrophysics of Galaxies · Physics 2019-05-07 Amit Kumar Mandal , Suvendu Rakshit , Indrani Pal , Chelliah Subramonian Stalin , Ram Sagar , Blesson Mathew

We present the main results from a long-term reverberation mapping campaign carried out for the Seoul National University Active Galactic Nuclei (AGN) Monitoring Project. High-quality data were obtained during 2015-2021 for 32 luminous AGNs…

We report the discovery of a luminosity distance estimator using Active Galactic Nuclei (AGN). We combine the correlation between the X-ray variability amplitude and the Black Hole (BH) mass with the single epoch spectra BH mass estimates…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Fabio La Franca , Stefano Bianchi , Gabriele Ponti , Enzo Branchini , Giorgio Matt

Scattering and absorption of light by a homogeneous distribution of intergalactic large dust grains has been proposed as an alternative, non-cosmological explanation for the faintness of Type Ia supernovae at $z\s im 0.5$. We investigate…

Astrophysics · Physics 2009-11-07 Ariel Goobar , Lars Bergstrom , Edvard Mortsell

Reverberation mapping is one of the main techniques used to study active galactic nuclei (AGN) accretion disks. Traditional continuum reverberation mapping uses short lags between variability in different wavelength AGN light curves on the…

Astrophysics of Galaxies · Physics 2026-01-15 Amy Secunda , Sebastian Wagner-Carena , Helen Qu , Shirley Ho

Reverberation mapping is now a well-established technique for investigating spatially-unresolved structures in the nuclei of distant galaxies with actively-accreting supermassive black holes. Structural parameters for the broad…

Astrophysics of Galaxies · Physics 2020-09-09 Misty C. Bentz

Continuum reverberation mapping (RM) is a powerful technique for constraining the accretion disk structure in active galactic nuclei (AGNs). In typical cases, the shorter-wavelength emission is used as the reference, and a positive time lag…

Astrophysics of Galaxies · Physics 2026-05-05 Chen MuLin , Cheng PeiZhen , Chen XingQian , Gu Ying , Zheng Qi , Liao GuiLin , Zhang XueGuang

Immensely bright quasars and radio-loud active galactic nuclei (AGNs) provide an enticing opportunity to construct standard candles detectable up to the very early universe. An analytic theory is proposed to measure the distance to powerful…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-24 Ross Turner , Stanislav Shabala

Continuum reverberation mapping probes the sizescale of the optical continuum-emitting region in active galactic nuclei (AGN). Through 3 years of multiwavelength photometric monitoring in the optical with robotic observatories, we perform…