Mubdi Rahman
A5090159160- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Astrophysical Phenomena and Observations
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- GNSS positioning and interference
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- earthquake and tectonic studies
- Astro and Planetary Science
- Remote Sensing in Agriculture
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Statistical and numerical algorithms
- History and Developments in Astronomy
- Adaptive optics and wavefront sensing
- Superconducting and THz Device Technology
- Scientific Research and Discoveries
- Ionosphere and magnetosphere dynamics
- Impact of Light on Environment and Health
- Advanced Frequency and Time Standards
Research Canada
2024
University of Toronto
2010-2024
Canadian Institute for Theoretical Astrophysics
2018-2023
Sidra Medical and Research Center
2021
Johns Hopkins University
2013-2017
Bloomberg (United States)
2017
We report on the discovery of eight repeating fast radio burst (FRB) sources found using Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. These span a dispersion measure (DM) range 103.5 to 1281 pc cm$^{-3}$. They display varying degrees activity: six were detected twice, another three times, and one ten times. FRBs likely represent bright and/or high-rate end distribution infrequently sources. For all sources, we determine sky coordinates with uncertainties...
We present a catalog of 536 fast radio bursts (FRBs) detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project between 400 and 800 MHz from 2018 July 25 to 2019 1, including 62 18 previously reported repeating sources. The represents first large sample, repeaters non-repeaters, observed in single survey with uniform selection effects. This facilitates comparative absolute studies FRB population. show that apparent non-repeaters have sky locations...
Abstract We report on the discovery and analysis of bursts from nine new repeating fast radio burst (FRB) sources found using Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. These span a dispersion measure (DM) range 195–1380 pc cm −3 . detect two three sources, four one source, five source. determine sky coordinates all with uncertainties ∼10′. Faraday rotation measures (RMs) for values −20(1) −499.8(7) rad m −2 , that are substantially lower than RM derived emitted by FRB...
Abstract We present a synthesis of fast radio burst (FRB) morphology (the change in flux as function time and frequency) detected the 400–800 MHz octave by FRB project on Canadian Hydrogen Intensity Mapping Experiment (CHIME/FRB), using events from first CHIME/FRB catalog. The catalog consists 62 bursts 18 repeating sources, plus 474 one-off FRBs, between 2018 July 25 2019 2. identify four observed archetypes (“simple broadband,” “simple narrowband,” “temporally complex,” “downward...
Following the first two annual intensity mapping workshops at Stanford in March 2016 and Johns Hopkins June 2017, we report on recent advances theory, instrumentation observation that were presented these meetings some of opportunities challenges identified looking forward. With preliminary detections CO, [CII], Lya low-redshift 21cm, a host experiments set to go online next few years, field is rapidly progressing all fronts, with great anticipation for flood new exciting results. This...
We present the discovery of 25 new repeating fast radio burst (FRB) sources found among CHIME/FRB events detected between 2019 September 30 and 2021 May 1. The were using a clustering algorithm that looks for multiple co-located on sky having similar dispersion measures (DMs). repeaters have DMs ranging from $\sim$220 pc cm$^{-3}$ to $\sim$1700 cm$^{-3}$, include exhibited as few two bursts many twelve. report statistically significant difference in both DM extragalactic (eDM) distributions...
We use the WMAP maximum entropy method foreground emission map combined with previously determined distances to giant HII regions measure free-free flux at Earth and luminosity of galaxy. find a total f_\nu=54211 Jy from 88 sources f_\nu=36043 Jy. The bulk are least marginally resolved, mean radii ~60 pc, electron density n_e ~ 9 cm^{-3}, filling factor \phi_{HII}=0.005 (over Galactic gas disk). dust-corrected ionizing photon is Q=3.2x10^{53} photons/s, in good agreement previous estimates....
Abstract We report on the detection of seven bursts from periodically active, repeating fast radio burst (FRB) source FRB 180916.J0158+65 in 300–400 MHz frequency range with Green Bank Telescope (GBT). Emission multiple is visible down to bottom GBT band, suggesting that cutoff (if it exists) for emission lower than 300 MHz. Observations were conducted during predicted periods activity source, and had simultaneous coverage Low Frequency Array (LOFAR) backend Canadian Hydrogen Intensity...
Fast Radio Burst FRB 20180916B in its host galaxy SDSS J015800.28+654253.0 at 149 Mpc is by far the closest-known with a robust association. The source also exhibits 16.35-day period bursting. Here we present optical and infrared imaging as well integral field spectroscopy observations of WFC3 camera on Hubble Space Telescope MEGARA spectrograph 10.4-m Gran Telescopio Canarias. 60-90 milliarcsecond (mas) resolution imaging, along previous 2.3-mas localization 20180916B, allow us to probe...
Abstract We report on the host association of FRB 20181030A, a repeating fast radio burst (FRB) with low dispersion measure (103.5 pc cm −3 ) discovered by CHIME/FRB Collaboration et al. Using baseband voltage data saved for its repeat bursts, we localize to sky area 5.3 arcmin 2 (90% confidence). Within localization region, identify NGC 3252 as most promising an estimated chance-coincidence probability <2.5 × 10 . Moreover, do not find any other galaxy M r < −15 AB mag within region...
Abstract The repeating FRB 20201124A was first discovered by CHIME/FRB in November of 2020, after which it seen to repeat a few times over several months. It entered period high activity April 2021, at time observatories recorded tens hundreds more bursts from the source. These follow-up observations enabled precise localization and host-galaxy identification. In this paper, we report on CHIME/FRB-detected 20201124A, including their best-fit morphologies, fluences, arrival times. large...
Abstract We present a Monte Carlo–based population synthesis study of fast radio burst (FRB) dispersion and scattering focusing on the first catalog sources detected with Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) project. simulate intrinsic properties propagation effects for variety FRB models compare simulated distributions measures timescales corresponding from CHIME/FRB catalog. Our simulations confirm results previous studies, which suggested that...
Abstract The CHIME/FRB project has detected hundreds of fast radio bursts (FRBs), providing an unparalleled population to statistically probe the foreground media that they illuminate. One such medium is ionized halo Milky Way (MW). We estimate total Galactic electron column density from FRB dispersion measures (DMs) as a function latitude using four different estimators, including ones assume spherical symmetry MW and imply more latitudinal variation in density. Our observation-based...
Fast radio burst (FRB) source 20180916B exhibits a 16.33-day periodicity in its activity. It is as of yet unclear what proposed mechanism produces the activity, but polarization information key diagnostic. Here, we report on properties 44 bursts from FRB detected between 2018 December and 2021 by CHIME/FRB, project Canadian Hydrogen Intensity Mapping Experiment Experiment. In contrast to previous observations, find significant variations Faraday rotation measure (RM) 20180916B. Over nine...
Abstract Fast radio bursts (FRBs) display a confounding variety of burst properties and host-galaxy associations. Repeating FRBs offer insight into the FRB population by enabling spectral, temporal, polarimetric to be tracked over time. Here, we report on polarized observations 12 repeating sources using multiyear monitoring with Canadian Hydrogen Intensity Mapping Experiment (CHIME) 400–800 MHz. We observe significant rotation measure (RM) variations from many in our sample, including RM...
Abstract In 2021, a catalog of 536 fast radio bursts (FRBs) detected with the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope was released by CHIME/FRB Collaboration. This large collection bursts, observed single instrument and uniform selection effects, has advanced our understanding FRB population. Here we update results for 140 these FRBs which channelized raw voltage (“baseband”) data are available. With voltages measured telescope’s antennas, it is possible to maximize...
Abstract Localizing fast radio bursts (FRBs) to their host galaxies is an essential step better understanding origins and using them as cosmic probes. The Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB Outriggers program aims add very long baseline interferometry localization capabilities CHIME, such that FRBs may be localized tens of milliarcsecond precision at the time discovery, more than sufficient for galaxy identification. first-built outrigger telescope Outrigger (KKO),...
Abstract The Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) Project has a new very long baseline interferometry (VLBI) Outrigger at the Green Bank Observatory (GBO), which forms 3300 km with CHIME operating 400–800 MHz. Using 100 ms full-array baseband “snapshots” collected commensally during FRB and pulsar triggers, we perform shallow, wide-area VLBI survey covering significant fraction of northern sky targeted positions compact sources from Fundamental Catalog....