BMX is a testbed transit radio telescope for developing techniques that will enable intensity mapping in 21cm. It has been built since 2017 on the ground of Brookhaven National Laboratory. It is composed of 4 closely packed off-axis 4m dishes that feed dual polarization receivers. It currently operates between 1100 MHz and 1550 MHz, but the current OMT is sensitive to frequencies above around 800MHz. Signals from 4 dishes are amplified and fed into 4 dual channel off-shelf PC digitizers and analyzed in real time in consumer grade GPUs, enabling very flexible development system. The current systems employs long FFT spectrometer giving an extremely clean spectral response. Calibration is done in a combination of noise injection at the OMT horn and on sky real and artifical sources. BMX is at latitude of 40.9 degrees allowing calibration from daily passage of Cyngus A. Unfortunately signal from Cygnus A is often obscured by one of my navigational satellites than transit BMX.
BMX is like a real 21cm experiments with simplicity and
flexibility of a testbed. One does not need to travel very far
to visit BMX and ones does not to spend days and days sorting
complicated clusters or hundreds of cables.
Main goals of BMX are:
🞻Develop beam calibration methods for future
experiments using fixed wing drones and quadricopters ;
🞻 Measure realistic overall system stability and how to
improve it;
🞻 Develop novel methods for RFI detection and rejection;
🞻 Develop data reduction methods for auto and
cross-correlation power spectrum measurements.
The core BMX team is composed of Anže Slosar (BNL), Paul O'Connor (BNL), Justine Haupt (BNL),Paul Stankus (BNL), William Tyndall (Yale) and Shree Murthy (BNL) with occasional help from Laura Newburg (Yale) and Jeff McMahon (Michigan). Many people have worked on BMX in the past, including Chris Sheey, Dana Zimmer, Guangyu Zhang, Evan Arena, Hindy Drillick, Chandler Conn, Lindsay Berkhout, Joe Winiecki and William Hueber.
We always welcome inquiries from scientific community or public. We are eager to develop new collaborators. Contact anze at bnl.gov.