TY - JOUR
T1 - CMB Shadows
T2 - The Effect of Interstellar Extinction on Cosmic Microwave Background Polarization and Temperature Anisotropy
AU - Nashimoto, Masashi
AU - Hattori, Makoto
AU - Chinone, Yuji
N1 - Publisher Copyright:
© 2020 The American Astronomical Society. All rights reserved.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2020/5/20
Y1 - 2020/5/20
N2 - We evaluate the degradation of the accuracy of the component separation between the cosmic microwave background (CMB) and foreground components caused by neglect of absorption of the CMB's monopole component by the galactic interstellar matter. The amplitude of the temperature anisotropy caused by the CMB shadow, due to dust components, is about 1 μK. This value is comparable to the required noise level necessary to probe non-Gaussianity studies with upcoming CMB experiments. In addition, the amplitude of the polarization caused by the CMB shadow due to dust is comparable to or larger than the rms value of the CMB B-mode polarization, imprinted by primordial gravitational waves. We show that applying a single-power-law model as the dust spectrum to observed multifrequency data introduces systematic errors, which are comparable to or larger than the required noise level for forthcoming CMB B-mode polarization experiments. Deducing the intrinsic spectrum of dust emission from the submillimeter wave band data reduces the systematic error to below the required noise level. However, this method requires dust temperature measurements with an accuracy of better than a few percent. We conclude that the CMB shadow due to dust must be considered in future CMB missions for achieving their targeted sensitivity. Our results will be important to detect the primordial CMB B-mode polarization, with the amplitude of the tensor-to-scalar ratio of r = 10-3
AB - We evaluate the degradation of the accuracy of the component separation between the cosmic microwave background (CMB) and foreground components caused by neglect of absorption of the CMB's monopole component by the galactic interstellar matter. The amplitude of the temperature anisotropy caused by the CMB shadow, due to dust components, is about 1 μK. This value is comparable to the required noise level necessary to probe non-Gaussianity studies with upcoming CMB experiments. In addition, the amplitude of the polarization caused by the CMB shadow due to dust is comparable to or larger than the rms value of the CMB B-mode polarization, imprinted by primordial gravitational waves. We show that applying a single-power-law model as the dust spectrum to observed multifrequency data introduces systematic errors, which are comparable to or larger than the required noise level for forthcoming CMB B-mode polarization experiments. Deducing the intrinsic spectrum of dust emission from the submillimeter wave band data reduces the systematic error to below the required noise level. However, this method requires dust temperature measurements with an accuracy of better than a few percent. We conclude that the CMB shadow due to dust must be considered in future CMB missions for achieving their targeted sensitivity. Our results will be important to detect the primordial CMB B-mode polarization, with the amplitude of the tensor-to-scalar ratio of r = 10-3
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U2 - 10.3847/2041-8213/ab9018
DO - 10.3847/2041-8213/ab9018
M3 - Article
AN - SCOPUS:85085874429
VL - 895
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
SN - 2041-8205
IS - 1
M1 - L21
ER -