scholarly journals Canadian Hydrogen Intensity Mapping Experiment (CHIME) pathfinder

2014 ◽  
Author(s):  
Kevin Bandura ◽  
Graeme E. Addison ◽  
Mandana Amiri ◽  
J. Richard Bond ◽  
Duncan Campbell-Wilson ◽  
...  
Keyword(s):  
Intensity Mapping ◽  
Mapping Experiment

scholarly journals Detector modules and spectrometers for the TIME-Pilot [CII] intensity mapping experiment

2016 ◽  
Author(s):  
Jonathon Hunacek ◽  
James Bock ◽  
C. Matt Bradford ◽  
Bruce Bumble ◽  
Tzu-Ching Chang ◽  
...  
Keyword(s):  
Intensity Mapping ◽  
Mapping Experiment

The Baryon Mapping eXperiment: a 21cm intensity mapping pathfinder

2020 ◽  
Author(s):  
Paul O'Connor ◽  
Anze Slosar ◽  
Maile Harris ◽  
Justine Haupt ◽  
John Kuczewski ◽  
...  
Keyword(s):  
Intensity Mapping ◽  
Mapping Experiment

scholarly journals The TIME-Pilot intensity mapping experiment

2014 ◽  
Author(s):  
A. T. Crites ◽  
J. J. Bock ◽  
C. M. Bradford ◽  
T. C. Chang ◽  
A. R. Cooray ◽  
...  
Keyword(s):  
Intensity Mapping ◽  
Mapping Experiment

Design and Fabrication of TES Detector Modules for the TIME-Pilot [CII] Intensity Mapping Experiment

2015 ◽  
Vol 184 (3-4) ◽  
pp. 733-738 ◽  
Author(s):  
J. Hunacek ◽  
J. Bock ◽  
C. M. Bradford ◽  
B. Bumble ◽  
T.-C. Chang ◽  
...  
Keyword(s):  
Intensity Mapping ◽  
Mapping Experiment

scholarly journals Fast Radio Burst Morphology in the First CHIME/FRB Catalog

2021 ◽  
Vol 923 (1) ◽  
pp. 1 ◽  
Author(s):  
Ziggy Pleunis ◽  
Deborah C. Good ◽  
Victoria M. Kaspi ◽  
Ryan Mckinven ◽  
Scott M. Ransom ◽  
...  
Keyword(s):  
Radio Burst ◽  
Intensity Mapping ◽  
Mapping Experiment ◽  
Propagation Effects ◽  
Fast Radio Burst ◽  
Morphological Differences ◽  
First Time

Abstract We present a synthesis of fast radio burst (FRB) morphology (the change in flux as a function of time and frequency) as detected in the 400–800 MHz octave by the FRB project on the Canadian Hydrogen Intensity Mapping Experiment (CHIME/FRB), using events from the first CHIME/FRB catalog. The catalog consists of 62 bursts from 18 repeating sources, plus 474 one-off FRBs, detected between 2018 July 25 and 2019 July 2. We identify four observed archetypes of burst morphology (“simple broadband,” “simple narrowband,” “temporally complex,” and “downward drifting”) and describe relevant instrumental biases that are essential for interpreting the observed morphologies. Using the catalog properties of the FRBs, we confirm that bursts from repeating sources, on average, have larger widths, and we show, for the first time, that bursts from repeating sources, on average, are narrower in bandwidth. This difference could be due to beaming or propagation effects, or it could be intrinsic to the populations. We discuss potential implications of these morphological differences for using FRBs as astrophysical tools.

scholarly journals The degeneracy between primordial non-Gaussianity and foregrounds in 21 cm intensity mapping experiments

2020 ◽  
Vol 499 (3) ◽  
pp. 4054-4067
Author(s):  
Steven Cunnington ◽  
Stefano Camera ◽  
Alkistis Pourtsidou
Keyword(s):  
Nuisance Parameter ◽  
Neutral Hydrogen ◽  
Real Data ◽  
Line Of Sight ◽  
Markov Chain Analysis ◽  
Significant Progress ◽  
Intensity Mapping ◽  
Chain Analysis ◽  
Parallel Text ◽  
Foreground Removal

ABSTRACT Potential evidence for primordial non-Gaussianity (PNG) is expected to lie in the largest scales mapped by cosmological surveys. Forthcoming 21 cm intensity mapping experiments will aim to probe these scales by surveying neutral hydrogen (H i) within galaxies. However, foreground signals dominate the 21 cm emission, meaning foreground cleaning is required to recover the cosmological signal. The effect this has is to damp the H i power spectrum on the largest scales, especially along the line of sight. Whilst there is agreement that this contamination is potentially problematic for probing PNG, it is yet to be fully explored and quantified. In this work, we carry out the first forecasts on fNL that incorporate simulated foreground maps that are removed using techniques employed in real data. Using an Monte Carlo Markov Chain analysis on an SKA1-MID-like survey, we demonstrate that foreground cleaned data recovers biased values [$f_{\rm NL}= -102.1_{-7.96}^{+8.39}$ (68 per cent CL)] on our fNL = 0 fiducial input. Introducing a model with fixed parameters for the foreground contamination allows us to recover unbiased results ($f_{\rm NL}= -2.94_{-11.9}^{+11.4}$). However, it is not clear that we will have sufficient understanding of foreground contamination to allow for such rigid models. Treating the main parameter $k_\parallel ^\text{FG}$ in our foreground model as a nuisance parameter and marginalizing over it, still recovers unbiased results but at the expense of larger errors ($f_{\rm NL}= 0.75^{+40.2}_{-44.5}$), which can only be reduced by imposing the Planck 2018 prior. Our results show that significant progress on understanding and controlling foreground removal effects is necessary for studying PNG with H i intensity mapping.

scholarly journals Mapping large-scale-structure evolution over cosmic times

2021 ◽  
Author(s):  
Marta B. Silva ◽  
Ely D. Kovetz ◽  
Garrett K. Keating ◽  
Azadeh Moradinezhad Dizgah ◽  
Matthieu Bethermin ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Large Scale ◽  
High Redshift ◽  
Formation Rate ◽  
Far Infrared ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Structure Evolution ◽  
Intensity Mapping ◽  
Wide Range

AbstractThis paper outlines the science case for line-intensity mapping with a space-borne instrument targeting the sub-millimeter (microwaves) to the far-infrared (FIR) wavelength range. Our goal is to observe and characterize the large-scale structure in the Universe from present times to the high redshift Epoch of Reionization. This is essential to constrain the cosmology of our Universe and form a better understanding of various mechanisms that drive galaxy formation and evolution. The proposed frequency range would make it possible to probe important metal cooling lines such as [CII] up to very high redshift as well as a large number of rotational lines of the CO molecule. These can be used to trace molecular gas and dust evolution and constrain the buildup in both the cosmic star formation rate density and the cosmic infrared background (CIB). Moreover, surveys at the highest frequencies will detect FIR lines which are used as diagnostics of galaxies and AGN. Tomography of these lines over a wide redshift range will enable invaluable measurements of the cosmic expansion history at epochs inaccessible to other methods, competitive constraints on the parameters of the standard model of cosmology, and numerous tests of dark matter, dark energy, modified gravity and inflation. To reach these goals, large-scale structure must be mapped over a wide range in frequency to trace its time evolution and the surveyed area needs to be very large to beat cosmic variance. Only a space-borne mission can properly meet these requirements.

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