- 96 views
On WednesdayFebruary 11th, 2026 we will hold our second monthly meeting of the year by Zoom only. We will NOT be having dinner at the pub beforehand.
Register in advance for this meeting:
https://us06web.zoom.us/meeting/register/E5X7E4C4REOfb_PD9oA6Sw
After registering, you will receive a confirmation email containing information about joining the meeting.
Agenda
- Welcome and Announcements - Malcolm Park
- Feature Presentation: Our presenter is Felix Thiel, who is a physics student from Queen's
- Title: Observing Black Holes from the Stratosphere
- 5 minute break
- What's Up in the Sky - Rick Wagner
- Members Reports (If you would like to present a member's report after the break, please let me know.)
Our presenter is Felix Thiel, who is a physics student from Queen's
Title: Observing Black Holes from the Stratosphere
Abstract:
In 2019, the Event Horizon Telescope (EHT) released the first-ever image of the super-massive black hole at the center of the radio galaxy M87. This image was taken using a technique called Very Long Baseline Interferometry (VLBI) which involved combining simultaneous observations (at 1.3 mm ) from radio telescopes all across the Earth effectively creating an Earth-sized telescope. Radio observations are diffraction limited and the resolution therefore depends on the size of the telescope and observing wavelength. The EHT hence is limited in two ways, on one hand the resolution is limited by the size of the Earth and on the other it is limited in wavelength by absorption of cosmic signals by the Earth's atmosphere. One solution to this problem is to put telescopes into space making the telescope array bigger and giving access to wavelengths that are not observable from the ground, the other (much cheaper) solution is to launch a telescope on a stratospheric balloon operating above 99.5% of the Earth's atmosphere. This would not increase the size of the telescope array but gives access to shorter wavelengths. In this talk I will give an overview of the Balloon-borne VLBI Experiment a 22 GHz (1.3cm) radio telescope with the aim to demonstrate that VLBI is possible between a stratospheric balloon and a ground-based telescope as well as the technical challenges associated with operating a radio telescope in the stratosphere. I will wrap up the talk by giving an overview of the impact on black-hole science that a millimetre balloon-borne VLBI station could have when combined with existing and future millimetre- VLBI arrays such as the EHT or next-generation EHT.
Biography:
I am a 3rd year PhD student in the Department of Physics at Queen's University, working with Laura Fissel on the balloon-borne VLBI Experiment (BVEX). I did my undergrad at McGill University under the supervision of Cynthia Chiang working on the Array of Long Baseline Antennas for Taking Radio Observations from the Sub-antarctic (ALBATROS). I then continued on to my Masters Degree at Queen's University working under the supervision of Laura Fissel on developing observing strategies for a 100 hour polarization survey with the new TolTEC camera on the Large Millimetre Telescope (LMT) located in Mexico.