https://www.um.edu.mt/library/oar/handle/123456789/16096 2026-07-15T13:24:12Z 2026-07-15T13:24:12Z Sheikh, Sofia Z. Kanodia, Shubham Lubar, Emily Bowman, William P. Cañas, Caleb I. Gilbertson, Christian MacDonald, Mariah G. Wright, Jason MacMahon, David Croft, Steve Price, Danny Siemion, Andrew P. V. Drew, Jamie Worden, S. Pete Trenholm, Elizabeth https://www.um.edu.mt/library/oar/handle/123456789/147572 2026-06-22T07:37:19Z 2023-01-01T00:00:00Z

Title: A Green Bank Telescope search for narrowband technosignatures between 1.1 and 1.9 GHz during 12 Kepler planetary transits Authors: Sheikh, Sofia Z.; Kanodia, Shubham; Lubar, Emily; Bowman, William P.; Cañas, Caleb I.; Gilbertson, Christian; MacDonald, Mariah G.; Wright, Jason; MacMahon, David; Croft, Steve; Price, Danny; Siemion, Andrew P. V.; Drew, Jamie; Worden, S. Pete; Trenholm, Elizabeth Abstract: Agrowing avenue for determining the prevalence of life beyond Earth is to search for “technosignatures” from extraterrestrial intelligences/agents. Technosignatures require significant energy to be visible across interstellar space and thus intentional signals might be concentrated in frequency, in time, or in space, to be found in mutually obvious places. Therefore, it could be advantageous to search for technosignatures in parts of parameter space that are mutually derivable to an observer on Earth and a distant transmitter. In this work, we used the L-band (1.1–1.9 GHz) receiver on the Robert C. Byrd Green Bank Telescope to perform the first technosignature search presynchronized with exoplanet transits, covering 12 Kepler systems. We used the Breakthrough Listen turboSETI pipeline to flag narrowband hits (∼3 Hz) using a maximum drift rate of ±614.4 Hz s−1 and a signal-to-noise threshold of 5—the pipeline returned ∼3.4 × 105 apparently-localized features. Visual inspection by a team of citizen scientists ruled out 99.6% of them. Further analysis found two signals of interest that warrant follow up, but no technosignatures. If the signals of interest are not redetected in future work, it will imply that the 12 targets in the search are not producing transit-aligned signals from 1.1 to 1.9 GHz with transmitter powers >60 times that of the former Arecibo radar. This search debuts a range of innovative technosignature techniques: citizen science vetting of potential signals of interest, a sensitivity-aware search out to extremely high drift rates, a more flexible method of analyzing on-off cadences, and an extremely low signal-to-noise threshold.

2023-01-01T00:00:00Z Tremblay, C. D. Varghese, S. S. Hickish, J. Demorest, P. B. Ng, C. Siemion, Andrew P. V. Czech, D. Donnachie, R. A. Farah, W. Gajjar, V. Lebofsky, M. MacMahon, D. H. E. Myburgh, T. Ruzindana, M. Bright, J. S. Erickson, A. Lacker, K. https://www.um.edu.mt/library/oar/handle/123456789/147515 2026-06-18T06:49:32Z 2024-01-01T00:00:00Z

Title: COSMIC : an ethernet-based commensal, multimode digital backend on the Karl G. Jansky very large array for the search for extraterrestrial intelligence Authors: Tremblay, C. D.; Varghese, S. S.; Hickish, J.; Demorest, P. B.; Ng, C.; Siemion, Andrew P. V.; Czech, D.; Donnachie, R. A.; Farah, W.; Gajjar, V.; Lebofsky, M.; MacMahon, D. H. E.; Myburgh, T.; Ruzindana, M.; Bright, J. S.; Erickson, A.; Lacker, K. Abstract: The primary goal of the search for extraterrestrial intelligence is to gain an understanding of the prevalence of technologically advanced beings (organic or inorganic) in the Galaxy. One way to approach this is to look for technosignatures: remotely detectable indicators of technology, such as temporal or spectral electromagnetic emissions consistent with an artificial source.With the new Commensal Open-Source Multimode Interferometer Cluster (COSMIC) digital backend on the Karl G. Jansky Very Large Array (VLA), we aim to conduct a search for technosignatures that is significantly more comprehensive, sensitive, and efficient than previously attempted. The COSMIC system is currently operational on the VLA, recording data and designed with the flexibility to provide user-requested modes. This paper describes the hardware system design, the current software pipeline, and plans for future development.

2024-01-01T00:00:00Z Zuckerman, Anna Ko, Zoe Isaacson, Howard Croft, Steve Price, Danny Lebofsky, Matt Siemion, Andrew P. V. https://www.um.edu.mt/library/oar/handle/123456789/147380 2026-06-12T13:26:00Z 2023-01-01T00:00:00Z

Title: The breakthrough listen search for intelligent life : a laser search pipeline for the automated planet finder Authors: Zuckerman, Anna; Ko, Zoe; Isaacson, Howard; Croft, Steve; Price, Danny; Lebofsky, Matt; Siemion, Andrew P. V. Abstract: The Search for Extraterrestrial Intelligence has traditionally been conducted at radio wavelengths, but optical searches are well-motivated and increasingly feasible due to the growing availability of high-resolution spectroscopy. We present a data analysis pipeline to search Automated Planet Finder (APF) spectroscopic observations from the Levy Spectrometer for intense, persistent, narrow-bandwidth optical lasers. We describe the processing of the spectra, the laser search algorithm, and the results of our laser search on 1983 spectra of 388 stars as part of the Breakthrough Listen search for technosignatures. We utilize an empirical spectra-matching algorithm called SpecMatch-Emp to produce residuals between each target spectrum and a set of best-matching catalog spectra, which provides the basis for a more sensitive search than previously possible. We verify that SpecMatch-Emp performs well on APF-Levy spectra by calibrating the stellar properties derived by the algorithm against the SpecMatch-Emp library and against Gaia catalog values. We leverage our unique observing strategy, which produces multiple spectra of each target per night of observing, to increase our detection sensitivity by programmatically rejecting events that do not persist between observations. With our laser search algorithm, we achieve a sensitivity equivalent to the ability to detect an 84 kW laser at the median distance of a star in our data set (78.5 ly). We present the methodology and vetting of our laser search, finding no convincing candidates consistent with potential laser emission in our target sample.

2023-01-01T00:00:00Z Sheikh, Sofia Z. Farah, Wael Pollak, Alexander W. Siemion, Andrew P. V. Chamma, Mohammed A. Cruz, Luigi F. Davis, Roy H. DeBoer, David R. Gajjar, Vishal Karn, Phil Kittling, Jamar Lu, Wenbin Masters, Mark Premnath, Pranav Schoultz, Sarah Shumaker, Carol Singh, Gurmehar Snodgrass, Michael https://www.um.edu.mt/library/oar/handle/123456789/147372 2026-06-12T12:25:50Z 2024-01-01T00:00:00Z

Title: Characterization of the repeating FRB 20220912A with the Allen telescope array Authors: Sheikh, Sofia Z.; Farah, Wael; Pollak, Alexander W.; Siemion, Andrew P. V.; Chamma, Mohammed A.; Cruz, Luigi F.; Davis, Roy H.; DeBoer, David R.; Gajjar, Vishal; Karn, Phil; Kittling, Jamar; Lu, Wenbin; Masters, Mark; Premnath, Pranav; Schoultz, Sarah; Shumaker, Carol; Singh, Gurmehar; Snodgrass, Michael Abstract: FRB 20220912A is a repeating Fast Radio Burst (FRB) that was discovered in Fall 2022 and remained highly active for several months. We report the detection of 35 FRBs from 541 h of follow-up observations of this source using the recently refurbished Allen Telescope Array, covering 1344 MHz of bandwidth primarily centred at 1572 MHz. All 35 FRBs were detected in the lower half of the band with non-detections in the upper half and covered fluences from 4–431 Jy-ms (median = 48.27 Jy-ms). We find consistency with previous repeater studies for a range of spectrotemporal features including: bursts with downward frequency drifting over time; a positive correlation between bandwidth and centre frequency; and a decrease in sub-burst duration over time. We report an apparent decrease in the centre frequency of observed bursts over the two months of the observing campaign (corresponding to a drop of 6.21 ± 0.76 MHz per d). We predict a cut-off fluence for FRB 20220912A of Fmax ≲ 104 Jy-ms, for this source to be consistent with the all-sky rate, and find that FRB 20220912A significantly contributed to the all-sky FRB rate at a level of a few per cent for fluences of ∼100 Jy-ms. Finally, we investigate characteristic time-scales and sub-burst periodicities and find (a) a median inter-subburst time-scale of 5.82 ± 1.16 ms in the multi-component bursts and (b) no evidence of strict periodicity even in the most evenly spaced multi-component burst in the sample. Our results demonstrate the importance of wideband observations of FRBs, and provide an important set of observational parameters against which to compare FRB progenitor and emission mechanism models.

2024-01-01T00:00:00Z