Minutes
1. Lo-z Galaxy/HI X-coupling paper - any tasks? Olivier is getting access to the proofs.
2. Follow up from Albert's presentation last week:
Green Bank Observatory Science Community Zoom.
Oct 26, 2022 01:00 PM Eastern Time (US and Canada)
Observatory News & Updates: Jim Jackson (GBO)
Science Presentation: Aya Keller (University of California, Berkeley)
A Model-Independent Dark Matter Search Using GBT Data
Abstract:A novel search technique for ultralight dark matter has been developed and carried out over a narrow range in L band, utilizing the recent Breakthrough Listen public data release of three years of observation with the Green Bank Telescope. The search concept depends only on the assumption of decay or annihilation of virialized dark matter to a quasimonochromatic radio line, additionally that the frequency and intensity of the line be consistent with most general properties expected of the phase space of our Milky Way halo. Specifically, the search selects for a line that exhibits a Doppler shift with position according to the solar motion through a static Galactic halo, and similarly varies in intensity with the position with respect to the Galactic center. Over the frequency range 1.73−1.83 GHz, radiative annihilation of dark matter is excluded above ⟨σv⟩ = 1.2×10−47 cm3 s−1, and for decay above λ = 4.1×10−35 s−1. The analysis of the full Breakthrough Listen GBT dataset by this method (25,000 spectra, 1.1−11.6 GHz) is currently underway.
https://us02web.zoom.us/j/85710429655?pwd=aXFjNGpSV0JQOHBoUWdNNjRCd0VUZz09
Passcode: 375054
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3. Good news - Xuelei: 'outriggers' funded for cylinder array through Northeastern University (where Yichao is). Furen is performing simulations to determine optimal locations. For baselines of a few km, 1 arcmin angular resolution feasible. May be good enough to localize FRBs to a single galaxy, or a few galaxies. May be some ambiguity in localizing source to a particular beam. (A larger bandwidth would help with this). Jixia showed map of Tianlai area and possible sites. Probably will be exact copies of existing cylinders. Expansion of correlator required as well. Time scale is soon - bids needed this year, construction in 2023. Our RF bandwidth may not be
4. Future topics
Greg and Peter hope to have a draft NSF proposal for inspection in ~ 1 week.
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