TY - JOUR

T1 - Distant foreground and the planck-derived hubble constant

AU - Yershov, V. N.

AU - Raikov, A. A.

AU - Lovyagin, N. Yu.

AU - Kuin, N. P.M.

AU - Popova, E. A.

PY - 2020/3

Y1 - 2020/3

N2 - It is possible to reduce the discrepancy between the local measurement of the cosmological parameter H0 and the value derived from the Planck measurements of the cosmic microwave background (CMB) by considering contamination of the CMB by emission from some medium around distant extragalactic sources, such as extremely cold coarse-grain dust. Though being distant, such a medium would still be in the foreground with respect to the CMB, and, as any other foreground, it would alter the CMB power spectrum. This could contribute to the dispersion of CMB temperature fluctuations. By generating a few random samples of CMB with different dispersions, we have checked that the increased dispersion leads to a smaller estimated value of H0, the rest of the cosmological model parameters remaining fixed. This might explain the reduced value of the Planck-derived parameter H0 with respect to the local measurements. The signature of the distant foreground in the CMB traced by supernovae (SNe) was previously reported by the authors of this paper – we found a correlation between the SN redshifts, zSN, and CMB temperature fluctuations at the SNe locations, TSN. Here we have used the slopes of the regression lines TSN /zSN corresponding to different Planck wavebands in order to estimate the possible temperature of the distant extragalactic medium, which turns out to be very low, about 5 K. The most likely ingredient of this medium is coarse-grain (grey) dust, which is known to be almost undetectable, except for the effect of dimming remote extragalactic sources.

AB - It is possible to reduce the discrepancy between the local measurement of the cosmological parameter H0 and the value derived from the Planck measurements of the cosmic microwave background (CMB) by considering contamination of the CMB by emission from some medium around distant extragalactic sources, such as extremely cold coarse-grain dust. Though being distant, such a medium would still be in the foreground with respect to the CMB, and, as any other foreground, it would alter the CMB power spectrum. This could contribute to the dispersion of CMB temperature fluctuations. By generating a few random samples of CMB with different dispersions, we have checked that the increased dispersion leads to a smaller estimated value of H0, the rest of the cosmological model parameters remaining fixed. This might explain the reduced value of the Planck-derived parameter H0 with respect to the local measurements. The signature of the distant foreground in the CMB traced by supernovae (SNe) was previously reported by the authors of this paper – we found a correlation between the SN redshifts, zSN, and CMB temperature fluctuations at the SNe locations, TSN. Here we have used the slopes of the regression lines TSN /zSN corresponding to different Planck wavebands in order to estimate the possible temperature of the distant extragalactic medium, which turns out to be very low, about 5 K. The most likely ingredient of this medium is coarse-grain (grey) dust, which is known to be almost undetectable, except for the effect of dimming remote extragalactic sources.

KW - Cosmic background radiation

KW - Cosmological parameters

KW - Dust, extinction

KW - Intergalactic medium

KW - NEARBY GALAXIES

KW - cosmic background radiation

KW - ISM PROPERTIES

KW - intergalactic medium

KW - H-0

KW - dust, extinction

KW - LOW-METALLICITY ENVIRONMENTS

KW - UNIVERSE

KW - cosmological parameters

KW - DUST PROPERTIES

UR - http://www.scopus.com/inward/record.url?scp=85089014305&partnerID=8YFLogxK

U2 - 10.1093/mnras/staa189

DO - 10.1093/mnras/staa189

M3 - Article

AN - SCOPUS:85089014305

VL - 492

SP - 5052

EP - 5056

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -