Characterizing the Broadband Reflection Spectrum of MAXI J1803-298 during Its 2021 Outburst with NuSTAR and NICER

Autor: Oluwashina K. Adegoke, Javier A. García, Riley M. T. Connors, Yuanze Ding, Guglielmo Mastroserio, James F. Steiner, Adam Ingram, Fiona A. Harrison, John A. Tomsick, Erin Kara, Missagh Mehdipour, Keigo Fukumura, Daniel Stern, Santiago Ubach, Matteo Lucchini

Publikováno v: The Astrophysical Journal, Vol 977, Iss 1, p 26 (2024)

MAXI J1803-298 is a transient black hole candidate discovered in 2021 May during an outburst that lasted several months. Multiple X-ray observations reveal recurring “dipping” intervals in several of its light curves, particularly during the hard

Externí odkaz: https://doaj.org/article/3c6e2d7943214ab0a144d8d7440a3aa1

Tell-Tale Spectral Signatures of MHD-driven Ultra-Fast Outflows in AGNs

Autor: Keigo Fukumura, Mauro Dadina, Gabriele Matzeu, Francesco Tombesi, Chris Shrader, Demosthenes Kazanas

We aim to explore spectral signatures of the predicted multi-ion UFOs in the broadband X-ray spectra of active galactic nuclei (AGNs) by exploiting an accretion disk wind model in the context of a simple magnetohydrodynamic (MHD) framework. We are fo

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::5aa130b66a12469acefa522b47e8af63
http://arxiv.org/abs/2205.08894

NuSTAR monitoring of MAXI J1348−630: evidence of high density disc reflection

Autor: Francesco Tombesi, John A. Tomsick, Sudip Bhattacharyya, Sudip Chakraborty, Ajay Ratheesh, Gaurava K. Jaisawal, Keigo Fukumura

Publikováno v: Chakraborty, S, Ratheesh, A, Bhattacharyya, S, Tomsick, J A, Tombesi, F, Fukumura, K & Jaisawal, G K 2021, ' NuSTAR monitoring of MAXI J1348−630: evidence of high density disc reflection ', Monthly Notices of the Royal Astronomical Society, vol. 508, no. 1, pp. 475-488 . https://doi.org/10.1093/mnras/stab2530

We present the broadband spectral analysis of all the six hard, intermediate and soft state NuSTAR observations of the recently discovered transient black hole X-ray binary MAXI J1348-630 during its first outburst in 2019. We first model the data wit

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::44e034d7fd4ac23bb9ae208ae0bdff3e
https://orbit.dtu.dk/en/publications/e6c962a4-2adb-438f-9caf-c3b670de5211

X-Ray Obscuration around Supermassive Black Holes in Active Galaxies

Autor: Abraham J. Reines, Keigo Fukumura

Publikováno v: Research Notes of the AAS. 6:123

We investigate obscuration of Active Galactic Nuclei (AGNs), identified as Supermassive Black Holes (BH) in luminous galaxies. In this model, winds of plasma particles launched from the accretion disk are photoionized by hard X-ray continua from the

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::83472dc5e578eada2b00a4d75afdd07f
https://doi.org/10.3847/2515-5172/ac76d0

Magnetically Advected Winds

Autor: Ioannis Contopoulos, Demos Kazanas, Keigo Fukumura

Publikováno v: Mon Not R Astron Soc Lett

Observations of X-ray absorption lines in magnetically driven disk winds around black hole binaries and active galactic nuclei yield a universal radial density profile rho proportional to r^{-1.2} in the wind. This is in disagreement with the standar

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c118bd5cc7e80d25e8c8db149c4b9d9e
https://pubmed.ncbi.nlm.nih.gov/32440307