Line intensity mapping (LIM) serves as a potent probe in astrophysics, relying on the statistical analysis of integrated spectral line emissions originating from distant star-forming galaxies. While LIM observations hold the promise of achieving a broad spectrum of scientific objectives, a significant hurdle for future experiments lies in distinguishing the targeted spectral line emitted at a specific redshift from undesired line emissions originating at different redshifts. The presence of these interloping lines poses a challenge to the accuracy of cosmological analyses. In this study, we introduce a novel approach to quantify line-line cross-correlations (LIM-LLX), enabling us to investigate the target signal amid instrumental noise and interloping emissions. For example, at a redshift of z similar to 3.7, we observed that the measured auto-power spectrum of C ii 158 exhibited substantial bias, from interloping line emission. However, cross-correlating C ii 158 with CO(6-5) lines using an FYST-like experiment yielded a promising result, with a signal-to-noise ratio of similar to 10. This measurement is notably unbiased. Additionally, we explore the extensive capabilities of cross-correlation by leveraging various CO transitions to probe the tomographic Universe at lower redshifts through LIM-LLX. We further demonstrate that incorporating low-frequency channels, such as 90 and 150 GHz, into FYST's EoR-Spec-like experiment can maximize the potential for cross-correlation studies, effectively reducing the bias introduced by instrumental noise and interlopers.

Cross-correlation Techniques to Mitigate the Interloper Contamination for Line Intensity Mapping Experiments / Roy, Anirban; Battaglia, Nicholas. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 969:1(2024), pp. 1-12. [10.3847/1538-4357/ad4a29]

Cross-correlation Techniques to Mitigate the Interloper Contamination for Line Intensity Mapping Experiments

Roy, Anirban;
2024-01-01

Abstract

Line intensity mapping (LIM) serves as a potent probe in astrophysics, relying on the statistical analysis of integrated spectral line emissions originating from distant star-forming galaxies. While LIM observations hold the promise of achieving a broad spectrum of scientific objectives, a significant hurdle for future experiments lies in distinguishing the targeted spectral line emitted at a specific redshift from undesired line emissions originating at different redshifts. The presence of these interloping lines poses a challenge to the accuracy of cosmological analyses. In this study, we introduce a novel approach to quantify line-line cross-correlations (LIM-LLX), enabling us to investigate the target signal amid instrumental noise and interloping emissions. For example, at a redshift of z similar to 3.7, we observed that the measured auto-power spectrum of C ii 158 exhibited substantial bias, from interloping line emission. However, cross-correlating C ii 158 with CO(6-5) lines using an FYST-like experiment yielded a promising result, with a signal-to-noise ratio of similar to 10. This measurement is notably unbiased. Additionally, we explore the extensive capabilities of cross-correlation by leveraging various CO transitions to probe the tomographic Universe at lower redshifts through LIM-LLX. We further demonstrate that incorporating low-frequency channels, such as 90 and 150 GHz, into FYST's EoR-Spec-like experiment can maximize the potential for cross-correlation studies, effectively reducing the bias introduced by instrumental noise and interlopers.
2024
969
1
1
12
https://doi.org/10.3847/1538-4357/ad4a29
https://arxiv.org/abs/2312.08471
Roy, Anirban; Battaglia, Nicholas
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/142135
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