Tootfinder

The Black Hole Explorer: Instrument System Overview
Daniel P. Marrone (University of Arizona), Janice Houston (Center for Astrophysics | Harvard/Smithsonian), Kazunori Akiyama (MIT Haystack Observatory, Mizusawa VLBI Observatory, BHI), Bryan Bilyeu (MIT Lincoln Laboratory), Don Boroson (MIT Lincoln Laboratory), Paul Grimes (Center for Astrophysics | Harvard/Smithsonian), Kari Haworth (Center for Astrophysics | Harvard/Smithsonian), Robert Lehmensiek (National Radio Astronomy Observator…

The Black Hole Explorer: Instrument System Overview
The Black Hole Explorer (BHEX) is a space very-long-baseline interferometry (VLBI) mission concept that is currently under development. BHEX will study supermassive black holes at unprecedented resolution, isolating the signature of the "photon ring" - light that has orbited the black hole before escaping - to probe physics at the edge of the observable universe. It will also measure black hole spins, study the energy extraction and acceleration mechanisms for black hole jets, and characterize …

Black Hole Spacetime and Properties of Accretion Flows and Jets Probed by Black Hole Explorer: Science Cases Proposed by BHEX Japan Team
Tomohisa Kawashima, Yuh Tsunetoe, Ken Ohsuga, Motoki Kino, Yosuke Mizuno, Kotaro Moriyama, Hiromi Saida, Kazunori Akiyama, Kazuhiro Hada, Kotaro Niinuma
https://arxiv.org/abs/2406.09995<…

Black Hole Spacetime and Properties of Accretion Flows and Jets Probed by Black Hole Explorer: Science Cases Proposed by BHEX Japan Team
Black Hole Explorer (BHEX) is a space VLBI mission concept, which can probe the black hole spacetime and the plasma properties including the magnetic fields of the accretion flows and relativistic jets. We propose science cases anticipated to be addressed by BHEX mainly via the imaging of the target objects, whose observational features appear in several microarcsecond scale. An appearance of a crescent-shaped shadow in a bright state of the M87 will be able to constrain the magnitude of the bl…

The Japanese Vision for the Black Hole Explorer Mission
Kazunori Akiyama, Kotaro Niinuma, Kazuhiro Hada, Akihiro Doi, Yoshiaki Hagiwara, Aya E. Higuchi, Mareki Honma, Tomohisa Kawashima, Dimitar Kolev, Shoko Koyama, Sho Masui, Ken Ohsuga, Hidetoshi Sano, Hideki Takami, Yuh Tsunetoe, Yoshinori Uzawa, Takuya Akahori, Yuto Akiyama, Peter Galison, Takayuki J. Hayashi, Tomoya Hirota, Makoto Inoue, Yuhei Iwata, Michael D. Johnson, Motoki Kino, Yutaro Kofuji, Yosuke Mizuno, Kotaro Moriyama, H…

The Japanese Vision for the Black Hole Explorer Mission
The Black Hole Explorer (BHEX) is a next-generation space very long baseline interferometry (VLBI) mission concept that will extend the ground-based millimeter/submillimeter arrays into space. The mission, closely aligned with the science priorities of the Japanese VLBI community, involves an active engagement of this community in the development of the mission, resulting in the formation of the Black Hole Explorer Japan Consortium. Here we present the current Japanese vision for the mission, r…

The Black Hole Explorer: Preliminary Antenna Design
T. K. Sridharan (National Radio Astronomy Observatory), R. Lehmensiek (National Radio Astronomy Observatory), D. Marrone (University of Arizona), M. Johnson (Center for Astrophysics, Harvard Smithsonian), J. Houston (Center for Astrophysics, Harvard Smithsonian), M. Freeman (Center for Astrophysics, Harvard Smithsonian), P. Cheimets (Center for Astrophysics, Harvard Smithsonian), M. Silver (MIT Lincoln Laboratory)

The Black Hole Explorer: Preliminary Antenna Design
We present the basic design of a large, light weight, spaceborne antenna for the Black Hole Explorer (BHEX) space Very Long Baseline Interferometry (space-VLBI) mission, achieving high efficiency operation at mm/sub-mm wavelengths. An introductory overview of the mission and its science background are provided. The BHEX mission targets fundamental black hole physics enabled by the detection of the finely structured image feature around black holes known as the photon ring, theoretically expecte…

The Black Hole Explorer Cryocooling Instrument
Hannah Rana, Kazunori Akiyama, Edgar Canavan, Michael DiPirro, Mark Freeman, Peter Galison, Paul Grimes, Mareki Honma, Janice Houston, Michael Johnson, Mark Kimball, Daniel Marrone, Edward Tong
https://arxiv.org/abs/2406.09975

The Black Hole Explorer Cryocooling Instrument
The Black Hole Explorer (BHEX) is a space-based very-long baseline interferometry (VLBI) mission aimed at precision black hole measurements, detecting the photon ring around black holes, exploring spacetime, spin, and mass properties, and validating predictions of General Relativity. These objectives are achieved using cryogenic receivers with quantum-limited sensitivities across a broad frequency range. Dual-band receivers at 80-106 GHz and 240-320 GHz require operating temperatures of 20 K an…

The Black Hole Explorer: Back End Electronics
Ranjani Srinivasan, Jonathan Weintroub, Rick Raffanti, Bryan Bilyeu, Thomas Gauron, John Test, Elliot Richards, Manuel Fernandez, Mark Freeman, Peter Cheimets, Mauricio Gendelman, Kari Haworth, Janice Houston, Michael D. Johnson, Emilia Mamani, Daniel Marrone, Ariel L. Pola, Jade Wang
https://

The Black Hole Explorer: Back End Electronics
This paper describes specification and early design of back end signal processing subsystems for the Black Hole Explorer (BHEX) Very Long Baseline Interferometry (VLBI) space telescope. The "back end" consists of two subsystems. First, the block downconverter (BDC) is a heterodyne system that performs a frequency translation of the analog signal from IF to baseband and amplifies and filters it for digitization. Second, the digital back end (DBE) samples the analog signal with an analog-to-digit…

High Data Rate Laser Communications for the Black Hole Explorer
Jade Wang, Bryan Bilyeu, Don Boroson, Dave Caplan, Kat Riesing, Bryan Robinson, Curt Schieler, Michael D. Johnson, Lindy Blackburn, Kari Haworth, Janice Houston, Sara Issaoun, Daniel Palumbo, Elliot Richards, Ranjani Srinivasan, Jonathan Weintroub, Dan Marrone
https://

High Data Rate Laser Communications for the Black Hole Explorer
The Black Hole Explorer (BHEX) is a mission concept that can dramatically improve state-of-the-art astronomical very long baseline interferometry (VLBI) imaging resolution by extending baseline distances to space. To support these scientific goals, a high data rate downlink is required from space to ground. Laser communications is a promising option for realizing these high data rate, long-distance space-to-ground downlinks with smaller space/ground apertures. Here, we present a scalable laser …

Ultra-low noise laser and optical frequency comb-based timing system for the Black Hole Explorer (BHEX) mission
Hannah Tomio, Guangning Yang, Holly F. Leopardi, Kenji Numata, Anthony W. Yu, Andrew Attar, Xiaozhen Xu, Wei Lu, Cheryl Gramling, T. K. Sridharan, Peter Kurczynski
https://arxiv.org/abs/2406.10222

Ultra-low noise laser and optical frequency comb-based timing system for the Black Hole Explorer (BHEX) mission
In this effort, we demonstrate the performance of a highly stable time reference for the proposed Black Hole Explorer (BHEX) mission, a space-based extension to the Event Horizon Telescope (EHT) Very Long Baseline Interferometry (VLBI) project. This precision timing system is based on the use of a space-qualified, ultra-low noise laser developed as part of the Laser Interferometer Space Antenna (LISA) mission as the timing reference, and an optical frequency comb to transfer the stability of th…

The Black Hole Explorer: Operating a Hybrid Observatory
Sara Issaoun, Kim Alonso, Kazunori Akiyama, Lindy Blackburn, Don Boroson, Peter Galison, Kari Haworth, Janice Houston, Michael D. Johnson, Yuri Y. Kovalev, Peter Kurczynski, Robert Lafon, Daniel P. Marrone, Daniel Palumbo, Eliad Peretz, Dominic Pesce, Leonid Petrov, Alexander Plavin, Jade Wang
h…

The Black Hole Explorer: Operating a Hybrid Observatory
We present a baseline science operations plan for the Black Hole Explorer (BHEX), a space mission concept aiming to confirm the existence of the predicted sharp ``photon ring" resulting from strongly lensed photon trajectories around black holes, as predicted by general relativity, and to measure its size and shape to determine the black hole's spin. BHEX will co-observe with a ground-based very long baseline interferometric (VLBI) array at high-frequency radio wavelengths, providing unpreceden…