BHEX Mini
BHEX Mini
Direct Imaging Black Holes from LEO
Ref Bari | 06/21 Update
BHEX Mini Next Steps
Physics
Engineering
Funding
BHEX Mini Next Steps
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
Decreased radiation environment in LEO vs. MEO
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
- SWaPC Requirements for Instrumentation
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
Decreased radiation environment in LEO vs. MEO
- What kind of targets can we observe with this angular resolution?
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
- What kind of targets can we observe with this angular resolution?
- SWaPC Requirements for Instrumentation
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
Decreased radiation environment in LEO vs. MEO
- What horizon-scale structure can we observe on long baselines?
- What extended structure can we probe on our shorter baseline?
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
- What kind of targets can we observe with this angular resolution?
- SWaPC Requirements for Instrumentation
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
- What horizon-scale structure can we observe on long baselines?
- What extended structure can we probe on our shorter baseline?
- What is the integration time for BHEX Mini on the (u,v) plane?
- Could that possibly enable direct imaging of dynamic accretion disk around Sgr A*? (i.e., creating a movie of a black hole!)
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
Decreased radiation environment in LEO vs. MEO
Decreased radiation environment in LEO vs. MEO
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
- What is the integration time for BHEX Mini on the (u,v) plane?
- Could that possibly enable direct imaging of dynamic accretion disk around Sgr A*? (i.e., creating a movie of a black hole!)
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
Decreased radiation environment in LEO vs. MEO
Decreased radiation environment in LEO vs. MEO
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
- What kind of targets can we observe with this angular resolution?
- SWaPC Requirements for Instrumentation
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
- What horizon-scale structure can we observe on long baselines?
- What extended structure can we probe on our shorter baseline?
- Can BHEX Mini enable imaging of dynamic accretion disk structure around Sgr A*?
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
- What is BHEX Mini's duty cycle? (i.e., how long will it be able to observe a radio target during one orbital period?)
- How much data will BHEX Mini collect over one orbit?
Decreased radiation environment in LEO vs. MEO
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
- What kind of targets can we observe with this angular resolution?
- SWaPC Requirements for Instrumentation
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
- What horizon-scale structure can we observe on long baselines?
- What extended structure can we probe on our shorter baseline?
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
- What is BHEX Mini's duty cycle? (i.e., how long will it be able to observe a radio target during one orbital period?)
- How much data will BHEX Mini collect over one orbit?
Decreased radiation environment in LEO vs. MEO
- How much less radiation (i.e., dosage per orbital period) will BHEX Mini in LEO have than BHEX in MEO?
- How much does that save us in mass? (i.e., because we don't have to radiation-harden our instrumentation)
- Can BHEX Mini enable imaging of dynamic accretion disk structure around Sgr A*?
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Challenges of Low-Earth Orbit at 86 GHz
- Virtually no ground station coverage due to high orbital velocity
- Cannot resolve Photon Ring at 86 GHz at LEO
- Space-Ground VLBI will be difficult due to atmospheric decoherence
- Interstellar medium scattering (ISM) is and significant for Sgr A*
- Prevents horizon-scale imaging for
- At 86 GHz, BHEX Mini has
I\propto \lambda^2
\lambda>2mm
\lambda=3.3mm
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
BHEX Mini Science Objectives (Safety)
- Supplement (u,v) coverage of Sgr A*/M87 at 86 GHz
BHEX Mini Science Objectives (Match)
- 86 GHz VLBI survey of AGN Targets with d~2.5m antenna
- Achieve Space-Space VLBI for the first time
BHEX Mini Science Objectives (Reach)
- Enable imaging of dynamical accretion disk phenomenon
- This would enable the first constraints on spin of Sgr A*
- Enable multi-messenger astronomy of binary black hole targets
- In conjunction with LIGO, LISA, or Einstein Telescope
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
BHEX Mini Next Steps
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
-
What material will we create the BHEX Mini antenna out of?
- This will determine the SWaPC requirements for the antenna
- What are state-of-the-art antenna designs with the least areal density?
-
Deployable vs. fixed antenna designs?
- Model surface accuracy of antenna
- Model aperture efficiency of antenna
- Phased array antenna design?
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
LT-RSP2 Cryocooler
Raytheon long life cryocoolers for future space missions (T. Conrad et. al., Cryogenics 2017)
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Stirling Cryocooler
Development of Advanced Two-Stage Stirling Cryocooler for Next Space Missions (Y. Sato et. al., Cryocoolers 15, 2009)
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Stirling Cryocooler
Development of Advanced Two-Stage Stirling Cryocooler for Next Space Missions (Y. Sato et. al., Cryocoolers 15, 2009)
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phase Coherence for BHEX Mini
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Phase Error
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Observing Frequency
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Timing Jitter
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Allan Deviation
\sigma_t = \sigma_f \cdot \Delta t
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Integration Time
\sigma_t = \sigma_f \cdot \Delta t
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Integration Time
\sigma_t = \sigma_f \cdot \Delta t
\sigma_f = 5\cdot 10^{-11}
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
\sigma_t = \sigma_f \cdot \Delta t
\sigma_f = 5\cdot 10^{-11}, f_{obs}=86 \text{ GHz}
\Delta t = 1s:
\sigma_t = 5\cdot 10^{-11} \cdot 1s = 5\cdot 10^{-11} s
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
\sigma_t = \sigma_f \cdot \Delta t
\sigma_f = 5\cdot 10^{-11}, f_{obs}=86 \text{ GHz}
\Delta t = 1s:
\sigma_t = 5\cdot 10^{-11} \cdot 1s = 5\cdot 10^{-11} s
\Delta \phi = 2\pi \cdot (86\cdot 10^9 \text{ Hz}) \cdot 5\cdot 10^{-11} s=27.01 \text{ rad}
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
\sigma_t = \sigma_f \cdot \Delta t
\sigma_f = 5\cdot 10^{-11}, f_{obs}=86 \text{ GHz}
\Delta t = 1s:
\sigma_t = 5\cdot 10^{-11} \cdot 1s = 5\cdot 10^{-11} s
\Delta \phi = 2\pi \cdot (86\cdot 10^9 \text{ Hz}) \cdot 5\cdot 10^{-11} s=27.01 \text{ rad}
\Delta t = 10s:
\sigma_t = 5\cdot 10^{-11} \cdot 10s = 50\cdot 10^{-11} s
\Delta \phi = 2\pi \cdot (86\cdot 10^9 \text{ Hz}) \cdot 50\cdot 10^{-11} s=270.01 \text{ rad}
\Delta \phi<1 \text{ rad for Phase Coherence}
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Coherence Loss for BHEX Mini
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss
Coherence Loss for BHEX Mini
Observing Frequency
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss for BHEX Mini
Integration Time
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Allan Deviation
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss for BHEX Mini
Allan Deviation
f=86 \text{ GHz}, t=10s, \sigma_y = 5\cdot 10^{-11}
ABRACON SMD OCXO
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss for BHEX Mini
Allan Deviation
f=86 \text{ GHz}, t=10s, \sigma_y = 5\cdot 10^{-11}
L = 1-\exp\left[-2\pi^{2}(86\cdot 10^9)^{2}(10)^{2}(5\cdot 10^{-11})^{2}\right]
ABRACON SMD OCXO
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss for BHEX Mini
Allan Deviation
f=86 \text{ GHz}, t=10s, \sigma_y = 5\cdot 10^{-11}
L = 1-\exp\left[-2\pi^{2}(86\cdot 10^9)^{2}(10)^{2}(5\cdot 10^{-11})^{2}\right]
ABRACON SMD OCXO
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
L\sim 1\%<10\% \text{ required for Phase Coherence}
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
-
Plot of Power v. Mass for selected USOs
- This will determine SWaPC requirements
- Plot of Visibility SNR for USOs/OCXOs
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
Eng
- SWaPC Requirements for Instrumentation
Fund
- Write Grant Proposals for Nelson Grants
- Write Abstract for SpaceCom 2026
- Write De-scoped BHEX Mini #1 & #2
BHEX Mini Next Steps
Phy
- What are BHEX Mini's primary science objectives?
- To what extent can BHEX Mini achieve its objectives?
BHEX Mini Science Objectives (Safety)
- Supplement (u,v) coverage of Sgr A*/M87 at 86 GHz
BHEX Mini Science Objectives (Match)
- 86 GHz VLBI survey of AGN Targets with d~2.5m antenna
- Achieve Space-Space VLBI for the first time
BHEX Mini Science Objectives (Reach)
- Enable imaging of dynamical accretion disk phenomenon
- This would enable the first constraints on spin of Sgr A*
- Enable multi-messenger astronomy of binary black hole targets
- In conjunction with LIGO, LISA, or Einstein Telescope
Todd Ely
Joseph Lazio
Eric Burt
Ben Hudson
Luke Anderson
Rick Fleeter
BHEX Mini Proposal Feedback
Todd Ely
BHEX Mini Proposal Feedback
Todd Ely
TLDR: It will be tough to fit an highly accurate clock on a small satellite
BHEX Mini Proposal Feedback
TLDR: It will be tough to fit an highly accurate clock on a small satellite
Eric Burt
- 🎯 Primary Science Objectives
- 🔭 SWAPC Requirements
- 📻 Antenna Dimensions
- 🧊 Cryocooler Requirements
- 🕰️ Frequency Reference System
- 🕒 BHEX Mini Timeline
- 💰Funding Deadlines
BHEX Mini
\text{MEO} (20000 \text{ km})
\text{LEO} (400 \text{ km})
\textbf{BHEX}
\textbf{BHEX Mini}
Metrics and motivations for Earth–space VLBI: Time-resolving Sgr A* with the Event Horizon Telescope (Palumbo et. al., ApJ 2019)
BHEX Mini
BHEX Mini Orbit
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
20,000\text{ km}
12000\text{ km}
400\text{ km}
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
12,000 \text{ km}
400\text{ km}
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
Michael Johnson et. al., BHEX Team, 2024
T_{orb}=90 \text{ min}
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Mid-Range Science Objectives for the Event Horizon Telescope (EHT Collaboration, 2024)
Multifrequency Black Hole Imaging for the Next-generation Event Horizon Telescope (Chael et. al., 2023, ApJ)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Less power required for data downlink from LEO than MEO:
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Maximum data transmission rate (in bits per second); How fast can you send data from BHEX Mini to the earth?
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Power of Transmitted Signal: Strength of downlink signal in Watts (i.e., shouting louder to be heard further away!)
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Transmitter Gain: How well-focused your signal is when it leaves the satellite
(i.e., shouting into a megaphone instead of into the wind)
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Receiver Gain: How effectively the ground station collects and concentrates the incoming signal (i.e., ALMA's big dish listening to our incoming signal)
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Antenna Efficiency: How efficient are
both the space and ground antennas?
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Noise Temperature: Background noise
of (similar to thermal noise) of receiver; Lower T means higher SNR.
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Bandwidth: How "wide" the signal is in frequency space. A high frequency bandwidth is good (except possibly for thermal noise*!)
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Bits per photon: How many bits each photon is encoded by (i.e., 1 bit or 2 bit)
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Received Power: How strong is the signal once it hits the ground receiver? (after traveling through empty space)
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
P_r = P_tG_tG_r \left( \frac{\lambda}{4\pi R}\right)^2 \cdot \eta
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
Distance: How much distance did the signal travel through free space? (LEO vs. MEO!)
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
P_r = P_tG_tG_r \left( \frac{\lambda}{4\pi R}\right)^2 \cdot \eta
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
Sub-milli arcsecond angular resolution:
BHEX Mini Unique Advantages
5.6 G \lambda < b_{s s}<9.3 G \lambda
0.11 G \lambda < b_{s g}<3.5 G \lambda
Dual short and long baseline lengths:
Rapid coverage of (u,v) plane:
T_{orb}=90 \text{ min}
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right)
Decreased signal loss from LEO:
Decreased radiation environment in LEO vs. MEO
22\mu as<\theta_{\text{BHEX-Mini}} < 1800 \mu as
5.6 G \lambda < b_{s s}<9.3 G \lambda , 0.11 G \lambda < b_{s g}<3.5 G \lambda
R_{\max } \approx \frac{P_t G_t G_r \eta}{k T_b B}\left(N_{\bmod }\right), G_r=\eta\left(\frac{\pi D}{\lambda}\right)^2
- 🎯 Primary Science Objectives
- 🔭 SWAPC Requirements
- 📻 Antenna Dimensions
- 🧊 Cryocooler Requirements
- 🕰️ Frequency Reference System
- 🕒 BHEX Mini Timeline
- 💰Funding Deadlines
BHEX Mini
🎯 Primary Science Objectives
Original Mission
Descoped Mission
Descope Mission #2
🎯 Primary Science Objectives
OG
- 86 GHz VLBI survey of AGN Targets with d~2.5m antenna
- Supplement (u,v) coverage of Sgr A*/M87 at 86 GHz
- Achieve first Space-Space VLBI
Descoped Mission
Descope Mission #2
🎯 Primary Science Objectives
OG
- 86 GHz VLBI survey of AGN Targets with d~2.5m antenna
- Supplement (u,v) coverage of Sgr A*/M87 at 86 GHz
- Achieve first Space-Space VLBI
DS1
- d~2m antenna cooled down to sub-25K temperatures
- No Frequency Phase Transfer from 86 to 230 GHz
- ABRACON OCXO for Frequency Reference System
Descope Mission #2
🎯 Primary Science Objectives
OG
- 86 GHz VLBI survey of AGN Targets with d~2.5m antenna
- Supplement (u,v) coverage of Sgr A*/M87 at 86 GHz
- Achieve first Space-Space VLBI
DS1
- d~2m antenna cooled down to sub-25K temperatures
- No Frequency Phase Transfer from 86 to 230 GHz
- ABRACON OCXO for Frequency Reference System
DS2
- 3 GHz VLBI survey of AGN targets
- No Space-Space VLBI with BHEX
- Ground-Space VLBI restricted to f~3 GHz ground stations
🎯 Primary Science Objectives
10 \text{ GHz}
47 \text{ GHz}
220 \text{ GHz}
1100 \text{ GHz}
\text{BHEX}
\text{BHEX Mini}
\text{EHT}
- 🎯 Primary Science Objectives
- 🔭 SWAPC Requirements
- 📻 Antenna Dimensions
- 🧊 Cryocooler Requirements
- 🕰️ Frequency Reference System
- 🕒 BHEX Mini Timeline
- 💰Funding Deadlines
BHEX Mini
🔭 SWAPC Requirements
Antenna
Cryocooler
Frequency Reference System
🔭 SWAPC Requirements
Antenna
- Antenna Diameter:
- Primary Receiver Temperature:
- Antenna Areal Density:
2.2< d < 2.5m
T_r \sim 20^{\circ}K
2<\sigma<5 \text{ kg}/\text{m}^2
Cryocooler
Frequency Reference System
🔭 SWAPC Requirements
Antenna
RSP2
- Raytheon RSP2: Sterling-PT Hybrid (450W Input)
- Stage 1 (Sterling): 6W at 60K
- Stage 2 (Pulse Tube): 2.1W at 20K
- Antenna Diameter:
- Primary Receiver Temperature:
- Antenna Areal Density:
2.2< d < 2.5m
T_r \sim 20^{\circ}K
2<\sigma<5 \text{ kg}/\text{m}^2
Frequency Reference System
🔭 SWAPC Requirements
Antenna
RSP2
- Raytheon RSP2: Sterling-PT Hybrid (450W Input)
- Stage 1 (Sterling): 6W at 60K
- Stage 2 (Pulse Tube): 2.1W at 20K
USO
- LISA USO:
- RK409 Rakon USO:
- O-CS41 ABRACON OCXO:
- Antenna Diameter:
- Primary Receiver Temperature:
- Antenna Areal Density:
2.2< d < 2.5m
T_r \sim 20^{\circ}K
2<\sigma<5 \text{ kg}/\text{m}^2
\sigma_y = 8\cdot 10^{-15} (t=10s)
\sigma_y = 1\cdot 10^{-12} (t=10s)
\sigma_y = 2\cdot 10^{-12}(t=1s)
🔭 SWAPC Requirements
Antenna
RSP2
- Raytheon RSP2: Sterling-PT Hybrid
- Stage 1 (Sterling): 6W at 60K
- Stage 2 (Pulse Tube): 2.1W at 20K
USO
- LISA USO:
- RK409 Rakon USO:
- O-CS41 ABRACON OCXO:
- Antenna Diameter:
- Primary Receiver Temperature:
- Antenna Areal Density:
2.2< d < 2.5m
T_r \sim 20^{\circ}K
2<\sigma<5 \text{ kg}/\text{m}^2
\sigma_y = 8\cdot 10^{-15}
\sigma_y = 1\cdot 10^{-12}
\sigma_y = 2\cdot 10^{-12}
- 🎯 Primary Science Objectives
- 🔭 SWAPC Requirements
- 📻 Antenna Dimensions
- 🧊 Cryocooler Requirements
- 🕰️ Frequency Reference System
- 🕒 BHEX Mini Timeline
- 💰Funding Deadlines
BHEX Mini
📻 Antenna Dimensions
3C 84
NRAO 530
NGC 1052
BL Lac
3C 273
📻 Antenna Dimensions
3C 84
NRAO 530
NGC 1052
BL Lac
3C 273
📻 Antenna Dimensions
3C 84: Nucleus of galaxy NGC 1275 (22 GHz)
NRAO 530
NGC 1052
BL Lac
3C 273
📻 Antenna Dimensions
3C 84
NRAO 530: Quasar 230 GHz, 20 μas (EHT)
NGC 1052
BL Lac
3C 273
📻 Antenna Dimensions
3C 84
NRAO 530
NGC 1052: Bright Elliptical Galaxy (65 mln lys)
BL Lac
3C 273
📻 Antenna Dimensions
3C 84
NRAO 530
NGC 1052
BL Lac
3C 279: An 'optically violent' variable quasar
Gamma Ray Image
📻 Antenna Dimensions
3C 84
NRAO 530
NGC 1052
BL Lac
3C 273
📻 Antenna Dimensions
📻 Antenna Dimensions
📻 Antenna Dimensions
📻 Antenna Dimensions
📻 Antenna Dimensions
📻 Antenna Dimensions
- 🎯 Primary Science Objectives
- 🔭 SWAPC Requirements
- 📻 Antenna Dimensions
- 🧊 Cryocooler Requirements
- 🕰️ Frequency Reference System
- 🕒 BHEX Mini Timeline
- 💰Funding Deadlines
BHEX Mini
🧊 Cryocooler Requirements
LT-RSP2 Cryocooler
Raytheon long life cryocoolers for future space missions (T. Conrad et. al., Cryogenics 2017)
🧊 Cryocooler Requirements
Stirling Cryocooler
Development of Advanced Two-Stage Stirling Cryocooler for Next Space Missions (Y. Sato et. al., Cryocoolers 15, 2009)
🧊 Cryocooler Requirements
Stirling Cryocooler
Development of Advanced Two-Stage Stirling Cryocooler for Next Space Missions (Y. Sato et. al., Cryocoolers 15, 2009)
🧊 Cryocooler Requirements
Stirling Cryocooler
Development of Advanced Two-Stage Stirling Cryocooler for Next Space Missions (Y. Sato et. al., Cryocoolers 15, 2009)
Phase Coherence for BHEX Mini
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Phase Error
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Observing Frequency
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Timing Jitter
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Allan Deviation
\sigma_t = \sigma_f \cdot \Delta t
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Integration Time
\sigma_t = \sigma_f \cdot \Delta t
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
Integration Time
\sigma_t = \sigma_f \cdot \Delta t
\sigma_f = 5\cdot 10^{-11}
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
\sigma_t = \sigma_f \cdot \Delta t
\sigma_f = 5\cdot 10^{-11}, f_{obs}=86 \text{ GHz}
\Delta t = 1s:
\sigma_t = 5\cdot 10^{-11} \cdot 1s = 5\cdot 10^{-11} s
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
\sigma_t = \sigma_f \cdot \Delta t
\sigma_f = 5\cdot 10^{-11}, f_{obs}=86 \text{ GHz}
\Delta t = 1s:
\sigma_t = 5\cdot 10^{-11} \cdot 1s = 5\cdot 10^{-11} s
\Delta \phi = 2\pi \cdot (86\cdot 10^9 \text{ Hz}) \cdot 5\cdot 10^{-11} s=27.01 \text{ rad}
Phase Coherence for BHEX Mini
\Delta \phi = 2\pi \cdot f \cdot \sigma_t
\sigma_t = \sigma_f \cdot \Delta t
\sigma_f = 5\cdot 10^{-11}, f_{obs}=86 \text{ GHz}
\Delta t = 1s:
\sigma_t = 5\cdot 10^{-11} \cdot 1s = 5\cdot 10^{-11} s
\Delta \phi = 2\pi \cdot (86\cdot 10^9 \text{ Hz}) \cdot 5\cdot 10^{-11} s=27.01 \text{ rad}
\Delta t = 10s:
\sigma_t = 5\cdot 10^{-11} \cdot 10s = 50\cdot 10^{-11} s
\Delta \phi = 2\pi \cdot (86\cdot 10^9 \text{ Hz}) \cdot 50\cdot 10^{-11} s=270.01 \text{ rad}
\Delta \phi<1 \text{ rad for Phase Coherence}
Phase Coherence for BHEX Mini
Coherence Loss for BHEX Mini
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss
Coherence Loss for BHEX Mini
Observing Frequency
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss for BHEX Mini
Integration Time
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Allan Deviation
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss for BHEX Mini
Allan Deviation
f=86 \text{ GHz}, t=10s, \sigma_y = 5\cdot 10^{-11}
ABRACON SMD OCXO
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss for BHEX Mini
Allan Deviation
f=86 \text{ GHz}, t=10s, \sigma_y = 5\cdot 10^{-11}
L = 1-\exp\left[-2\pi^{2}(86\cdot 10^9)^{2}(10)^{2}(5\cdot 10^{-11})^{2}\right]
ABRACON SMD OCXO
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
Coherence Loss for BHEX Mini
Allan Deviation
f=86 \text{ GHz}, t=10s, \sigma_y = 5\cdot 10^{-11}
L = 1-\exp\left[-2\pi^{2}(86\cdot 10^9)^{2}(10)^{2}(5\cdot 10^{-11})^{2}\right]
ABRACON SMD OCXO
L = 1-\exp\left(-2\pi^{2}f^{2}t^{2}\sigma_y^{2}\right)
L\sim 1\%<10\% \text{ required for Phase Coherence}
Antenna Diameter for BHEX Mini
🕒 Prospective Timeline
June
July
August
September
🕒 Prospective Timeline
June
July
August
September
- NASA NIAC 2025 Phase I Step I
- SpaceCom Conference 2026
- Brown Nelson + Hazeltine Grants
-
Antenna Focus
- Nacer Chahat
- Emmanuel Decrossas
🕒 Prospective Timeline
June
July
August
September
-
Cryocooler Focus
- Lucas Anderson
- Katelyn Boushon
- NSF Foundational Research in Robotics Grant (FRR)
- Fall Walls Foundation Selections
- NASA NIAC 2025 Phase I Step I
- SpaceCom Conference 2026
- Brown Nelson + Hazeltine Grants
-
Antenna Focus
- Nacer Chahat
- Emmanuel Decrossas
🕒 Prospective Timeline
June
July
Aug
September
-
Cryocooler Focus
- Lucas Anderson
- Katelyn Boushon
- NSF Foundational Research in Robotics Grant (FRR)
- Fall Walls Foundation Selections
- Brown University Co-Lab
- NASA NIAC Phase I Round I Step B Selections Announced
-
Solar Panel Focus
- DCubed Inc.
- DHV Tech
- NASA NIAC 2025 Phase I Step I
- SpaceCom Conference 2026
- Brown Nelson + Hazeltine Grants
-
Antenna Focus
- Nacer Chahat
- Emmanuel Decrossas
🕒 Prospective Timeline
June
July
Aug
Sep
-
Cryocooler Focus
- Lucas Anderson
- Katelyn Boushon
- NSF Foundational Research in Robotics Grant (FRR)
- Fall Walls Foundation Selections
- Brown University Co-Lab
- NASA NIAC Phase I Round I Step B Selections Announced
-
Solar Panel Focus
- DCubed Inc.
- DHV Tech
- NSF Advanced Technologies and Instrumentation for the Astronomical Sciences (ATI)
-
Data Downlink Focus
- MIT Lincoln Labs
- ALICE/CLICK Teams
- NASA NIAC 2025 Phase I Step I
- SpaceCom Conference 2026
- Brown Nelson + Hazeltine Grants
-
Antenna Focus
- Nacer Chahat
- Emmanuel Decrossas
🕒 Prospective Timeline
Antenna
🕒 Prospective Timeline
Cryocooler
🕒 Prospective Timeline
Solar Panels
🕒 Prospective Timeline
Orbital Parameters
🕒 Prospective Timeline
Data Downlink
🕒 Prospective Timeline
Systems Integration
- 🕒 Prospective Timeline
- 💰Funding Deadlines
- 🎯 Primary Science Objectives
- 🔭 Antenna Requirements
- 🧠 Ideas!
BHEX Mini
💰Funding Oppurtunities
June
$3,000
💰Funding Oppurtunities
July
$175,000
$3,000
$175,000
💰Funding Oppurtunities
Sep
$175,000
$3,000
$250,000
💰Funding Oppurtunities
Oct
$175,000
$3,000
$250,000
💰Funding Oppurtunities
- 🕒 Prospective Timeline
- 💰Funding Deadlines
- 🎯 Primary Science Objectives
- 🔭 Antenna Requirements
- 🧠 Ideas!
BHEX Mini
\textbf{Primary Science Objective: }\text{Resolve extended black hole structure}
\text{Image black hole accretion disk at low frequency}
\text{Increase number of short Space-Ground baselines}
\text{Achieve first Space-Space VLBI}
🎯 Mission Statement
10 \text{ GHz}
47 \text{ GHz}
220 \text{ GHz}
1100 \text{ GHz}
🎯 Mission Statement
10 \text{ GHz}
47 \text{ GHz}
220 \text{ GHz}
1100 \text{ GHz}
\text{BHEX}
\text{BHEX Mini}
\text{EHT}
🎯 Mission Statement
\textbf{BHEX Mini}
\text{PR: 86 GHz}
\textbf{BHEX}
\text{PR: 230-345 GHz}\\ \text{SR: 86-120 GHz}
- 🕒 Prospective Timeline
- 💰Funding Deadlines
- 🎯 Primary Science Objectives
- 🔭 Antenna Requirements
- 🧠 Ideas!
BHEX Mini
D
D\sim2 m
T\sim20^{\circ}K
Secondary
Science Targets
Gaussian Source Approximation
Visibility Amplitudes
Thermal Noise Constraints
\sigma_{GS}=\frac{1}{\eta_{\mathrm{Q}}} \sqrt{\frac{\mathrm{SEFD}_{\mathrm{G}} \mathrm{SEFD}_{\mathrm{S}}}{2 \Delta \nu \Delta t}}
SEFD Constraint
\sigma_{GS}=\frac{1}{\eta_{\mathrm{Q}}} \sqrt{\frac{\mathrm{SEFD}_{\mathrm{G}} \mathrm{SEFD}_{\mathrm{S}}}{2 \Delta \nu \Delta t}}
\mathrm{SEFD}_S=\frac{2 k_{\mathrm{B}} T_{\mathrm{sys}}^*}{\eta_{\mathrm{A}} A}
Constraints
T,A
\sigma_{GS}=\frac{1}{\eta_{\mathrm{Q}}} \sqrt{\frac{\mathrm{SEFD}_{\mathrm{G}} \mathrm{SEFD}_{\mathrm{S}}}{2 \Delta \nu \Delta t}}
\mathrm{SEFD}_S=\frac{2 k_{\mathrm{B}} T_{\mathrm{sys}}^*}{\eta_{\mathrm{A}} A}
Parameter Space
\sigma, T,A
\sigma_{GS}=\frac{1}{\eta_{\mathrm{Q}}} \sqrt{\frac{\mathrm{SEFD}_{\mathrm{G}} \mathrm{SEFD}_{\mathrm{S}}}{2 \Delta \nu \Delta t}}
D
\mathrm{SEFD}_S=\frac{2 k_{\mathrm{B}} T_{\mathrm{sys}}^*}{\eta_{\mathrm{A}} A}
Antenna Diameter + Temperature!
Visibility Amplitudes
Visibility Amplitudes
Visibility Amplitudes
Visibility Amplitudes
Visibility Amplitudes
Delta
Visibility Amplitudes
Delta
Visibility Amplitudes
Delta
Visibility Amplitudes
Delta
Visibility Amplitudes
Delta
V(b) = S\cdot \exp(-\pi^2 b^2\theta^2/4\ln 2)
V(b) = S\cdot \exp(-\pi^2 b^2\theta^2/4\ln 2)
\sigma_{SS}<\frac{|V_{SS}|}{SNR}, \sigma_{SG}<\frac{|V_{SG}|}{SNR}
\sigma_{SS}<\frac{|V_{SS}|}{SNR}, \sigma_{SG}<\frac{|V_{SG}|}{SNR}
BHEX Mini
- 🕒 Prospective Timeline
- 💰Funding Deadlines
- 🎯 Primary Science Objectives
- 🔭 Antenna Requirements
- 🧠 Introduction to (u,v) Plane
🧠 The (u,v) Plane
🧠 The (u,v) Plane
🧠 The (u,v) Plane
🧠 The (u,v) Plane
🧠 The (u,v) Plane
🧠 The (u,v) Plane
🧠 The (u,v) Plane
🧠 The (u,v) Plane
Goal:
I(l,m)
🧠 The (u,v) Plane
I(l,m)
Intensity of a certain part of the sky/
sky brightness pattern
Goal: Measure
🧠 The (u,v) Plane
Goal: Measure
I(l,m)
Coordinates in the sky
🧠 The (u,v) Plane
Now we add the effects of the radio interferometer ...
I(l,m)
Coordinates in the sky
🧠 The (u,v) Plane
Now we add the effects of the radio interferometer ...
I(l,m)
Multiplicative envelope:
comes from size of antennas
A(l,m)
🧠 The (u,v) Plane
Now we add the effects of the radio interferometer ...
I(l,m)
Simulates interference pattern
A(l,m)
e^{-2\pi i (ul+vm)}
🧠 The (u,v) Plane
Now we add the effects of the radio interferometer ...
I(l,m)
(u,v): Baseline vector
u: East-west baseline distance
v: North-south baseline distance
A(l,m)
e^{-2\pi i (ul+vm)}
\vec{b}=(u,v)
🧠 The (u,v) Plane
Take all the signals from the sky and add them up ...
I(l,m)
A(l,m)
e^{-2\pi i (ul+vm)}
\int
dl dm
V(u,v)=
🧠 The (u,v) Plane
Take all the signals from the sky and add them up ...
I(l,m)
A(l,m)
e^{-2\pi i (ul+vm)}
\int
dl dm
V(u,v)=
Visibility Function
🧠 The (u,v) Plane
Take all the signals from the sky and add them up ...
I(l,m)
A(l,m)
e^{-2\pi i (ul+vm)}
\int
dl dm
V(u,v)=
Multiplicative Envelope
🧠 The (u,v) Plane
Take all the signals from the sky and add them up ...
I(l,m)
A(l,m)
e^{-2\pi i (ul+vm)}
\int
dl dm
V(u,v)=
Sky Intensity/Brightness
🧠 The (u,v) Plane
Take all the signals from the sky and add them up ...
I(l,m)
A(l,m)
e^{-2\pi i (ul+vm)}
\int
dl dm
V(u,v)=
Interferometric Pattern
\vec{b}=(u,v)
🧠 The (u,v) Plane
It's a Fourier Transformation!
I(l,m)
A(l,m)
e^{-2\pi i (ul+vm)}
\int
dl dm
V(u,v)=
One pair of antennas measures one single point on the (u,v) plane: one fourier mode!
🧠 The (u,v) Plane
It's a Fourier Transformation!
I(l,m)
A(l,m)
e^{-2\pi i (ul+vm)}
\int
dl dm
V(u,v)=
What we want
🧠 The (u,v) Plane
It's a Fourier Transformation!
I(l,m)
A(l,m)
e^{-2\pi i (ul+vm)}
\int
dl dm
V(u,v)=
What we get :(
🧠 The (u,v) Plane
It's a Fourier Transformation!
Fill up the (u,v) plane
and then fourier transform back to the real image!
🧠 The (u,v) Plane
It's a Fourier Transformation!
Fill up the (u,v) plane
and then fourier transform back to the real image!
🧠 The (u,v) Plane
But how do you fill up the (u,v) plane?
🧠 The (u,v) Plane
But how do you fill up the (u,v) plane?
- Use an array of antennas!
N \text{ antennas} = \frac{N(N-1)}{2} \text{ baselines}
🧠 The (u,v) Plane
- Use an array of antennas!
N \text{ antennas} = \frac{N(N-1)}{2} \text{ baselines}
🧠 The (u,v) Plane
- Use an array of antennas!
4 \text{ antennas} = \frac{4(3)}{2}=6 \text{ baselines}
🧠 The (u,v) Plane
But how do you fill up the (u,v) plane?
- Use an array of antennas!
N \text{ antennas} = \frac{N(N-1)}{2} \text{ baselines}
2. Earth Rotation Aperture Synthesis
\vec{u} = \frac{\vec{b}\cdot \hat{s}}{\lambda}
🧠 The (u,v) Plane
2. Earth Rotation Aperture Synthesis
\vec{u} = \frac{\vec{b}\cdot \hat{s}}{\lambda}
\vec{b}\cdot \hat{s}
BHEX Mini | 06/21 Update
By Ref Bari
