CMB Rest Frame Research Articles

Bayesian estimation of our local motion from the Planck-2018 CMB temperature map

The largest fluctuation in the CMB sky is the CMB dipole, which is believed to be caused by the motion of our observation frame with respect to the CMB rest frame. This motion accounts for the known motion of the Solar System barycentre with a best-fit amplitude of 369 km/s, in the direction (ℓ= 264°, b=48°) in galactic coordinates. Along with the CMB dipole signal, this motion also causes an inevitable signature of statistical anisotropy in the higher multipoles due to the modulation and aberration of the CMB temperature and polarization fields. This leads to a correlation between adjacent CMB multipoles causing a non-zero value of the off-diagonal terms in the covariance matrix which can be captured in terms of the dipolar spectra of the bipolar spherical harmonics (BipoSH). In our work, we jointly infer the CMB power spectrum and the BipoSH spectrum in a Bayesian framework using the Planck-2018 SMICA temperature map. We detect amplitude and direction of the local motion consistent with the canonical value v=369 km/s inferred from CMB dipole with a statistical significance of 4.54σ, 4.97σ and 5.23σ respectively from the masked temperature map with the available sky fraction 40.1%, 59.1%, and 72.2%, confirming the common origin of both the signals. The Bayes factor in favor of the canonical value is between 7 to 8 depending on the choice of mask. But it strongly disagrees (by a value of the Bayes factor about 10-10–10-11) with a higher value of local motion which one can infer from the amplitude of the dipole signal obtained from the CatWISE2020 quasar catalog using the WISE and NEOWISE data set.

Is there really a Hubble tension?

The heliocentric redshifts (z hel) reported for 150 type Ia supernovae in the Pantheon compilation are significantly discrepant from their corresponding values in the JLA compilation. Both catalogues include corrections to the redshifts and magnitudes of the supernovae to account for the motion of the heliocentric frame relative to the ‘CMB rest frame’, as well as corrections for the directionally coherent bulk motion of local galaxies with respect to this frame. The latter is done employing modelling of peculiar velocities which assume the ΛCDM cosmological model but nevertheless provide evidence for residual bulk flows which are discordant with this model (implying that the observed Universe is in fact anisotropic). Until recently such peculiar velocity corrections in the Pantheon catalogue were made at redshifts exceeding 0.2 although there is no data on which to base such corrections. We study the impact of these vexed issues on the 4.4σ discrepancy between the Hubble constant of H 0 = 67.4 ± 0.5 km s−1 Mpc−1 inferred from observations of CMB anisotropies by Planck assuming ΛCDM, and the measurement of H 0 = 73.5 ± 1.4 km s−1 Mpc−1 by the SH0ES project which extended the local distance ladder using type Ia supernovae. Using the same methodology as the latter study we find that for supernovae whose redshifts are discrepant between Pantheon and JLA with Δz hel > 0.0025, the Pantheon redshifts favour H 0 ≃ 72 km s−1 Mpc−1, while the JLA redshifts favour H 0 ≃ 68 km s−1 Mpc−1. Thus the discrepancies between SNe Ia datasets are sufficient to undermine the claimed ‘Hubble tension’. We further note the systematic variation of H 0 by ∼6–9 km s−1 Mpc−1 across the sky seen in multiple datasets, implying that it cannot be measured locally to better than ∼10% in a model-independent manner.

Theory of Dark Matter and Dark Energy

In this article, we propose a new model of dark matter. According to this new model, dark matter is a substance, that is a new physical element not constituted of classical particles, called dark substance and filling the Universe. Assuming some very simple physical properties to this dark substance, we theoretically justify the flat rotation curve of galaxies and the baryonic Tully-Fisher’s law. We then study according to our new theory of dark matter  the different possible distributions of dark matter in galaxies and in galaxy clusters, and the velocities of galaxies in galaxy clusters.
 
 Then using the new model of dark matter we are naturally led to propose a new geometrical model of Universe, finite, that is different from all geometrical models proposed by the Standard Cosmological Model (SCM). Despite that our Theory of dark matter is compatible with the SCM, we then expose a new Cosmological model based on this new geometrical form of the Universe and on the interpretation of the CMB Rest Frame (CRF), that has not physical interpretation on the SCM and that we will call local Cosmological frame. We then propose 2 possible mathematical models of expansion inside the new Cosmological model. The 1st mathematical model is based on General Relativity as the SCM and gives the same theoretical predictions of distances and of the Hubble’s constant as the SCM. The 2nd mathematical model of expansion of the Universe is mathematically much simpler than the mathematical model of expansion used in the SCM, but we will see that its theoretical predictions are in agreement with astronomical observations. Moreover, this 2nd mathematical model of expansion does not need to introduce the existence of a dark energy contrary to the mathematical model of expansion of the SCM. To end we study the evolution of the temperature of dark substance in the Universe and we make appear the existence of a dark energy, due to our model of dark matter.

E(2) gauge theory model of effective gravitational theory at large scale

At the cosmological scale, there exist many anisotropic anomalies in the low-l multipoles of the CMB angular power spectrum. Especially, the normals to the octopole and quadrupole planes are aligned with the direction of the cosmological dipole at a level inconsistent with Gaussian random. The inconsistency indicates that the anomalies may not be boost effect from the CMB rest frame to the peculiar frame. It hints us that the boost invariance might be violated on a cosmological scale. There are some discrepancies between the astronomical and cosmological observations, and the predictions are solely based on general relativity and the standard model for elementary particle physics. The solutions are the introduction of dark matter and dark energy. However, all the experiments aiming at finding dark matter particles give negative result and it is still a mystery:what the dark energy is comprised of. We suppose that the Lorentz symmetry begins to be violated partly from the scale of galaxy and utilize the very special relativity symmetry group E(2) as an example to illustrate the Lorentz violation effect on the large-scale effective gravity. A local E(2) but Lorentz invariant gauge theory can be constructed based on the equivalence principle and the gauge principle. To realize the E(2) symmetry, the closure requirement of Maurer-Cartan eqnarray on E(2) algebra needs to be satisfied by postulating constraint conditions among the components of the Lorentz connection. The local Lorentz invariant gauge theory with a Hilbert-Einstein action is a theory with torsion in general case. However in the case of scalar matter source, the theory is exactly the theory of general relativity with Levi-Civita connection and zero torsion. In the E(2) gauge theory case, the closure requirement of Maurer-Cartan eqnarray for E(2) algebra postulates 12 constraint eqnarrays among the components of the Lorentz connection and the eqnarrays of motion for connection reduce the number of independent components of connection to 12. The eqnarrays of motion for the tetrad field do not contain only the involved tetrad field components nor these relevant independent components. So the whole number of variables needed to be solved is 12 more than that in general relativity while there are 12 more eqnarrays in the meantime. The torsion or the contortion field of the E(2) gauge theory is non-trivial even in the case of scalar matter source distribution. Decompose the connection into Levi-Civita one and the contortion part and rewrite the eqnarrays for tetrad field in the formalism of general relativity, then there will appear an effective energy-momentum tensor contributed by the contortion distribution, in addition to the ordinary matter source distribution even for the case of scalar matter source. We expect it to contribute at least part of the dark matter effect. We also examine the holding of the first and second Bianchi identities induced by Jacobi identity of the E(2) gauge theory. The approach of our modified gravity is different from other approach of modified gravity in the sense that we construct the modified gravity by modifying the spacetime symmetry on a large scale and the emergence of effective energy-momentum tensor caused by Lorentz violation effect is due to a purely large scale effect.

On the Trigonometric Description of the Michelson-Morley Experiment

<p class="1Body">One formula with two trigonometric corrections describing the round trip of the beams in the Michelson-Morley experiment is presented. The first trigonometric correction describes the round trip path of those beams, while the second trigonometric correction describes the trigonometric geometric mean of the two-way speed of those beams. This formula gives the null fringe shift result for the first order experiments (Fizeau experiment, Hoek experiment), the null fringe shift result for the second order experiment (Michelson-Morley experiment), and predicts a measurable fringe shift result for the fourth order experiment. This trigonometric model can be tested experimentaly by the advanced LIGO (Laser Interferometer Gravitational-Waves Observatory) technology with three arms separated by the angle π/4 and the longitudinal arm directed to the CMB rest frame in the direction to the constellation Crater (known in the Greek mythology as the Cup of the god Apollo). This proposed fourth order experiment can be named as the advanced LIFE (Laser Interferometer Fringe Enigma) experiment. The published predictions before the arrival of experimental data from the advanced LIFE experiment can estimate the power of our models.</p>

Improving Planck calibration by including frequency-dependent relativistic corrections

The Planck satellite detectors are calibrated in the 2015 release using the “orbital dipole”, which is the time-dependent dipole generated by the Doppler effect due to the motion of the satellite around the Sun. Such an effect has also relativistic time-dependent corrections of relative magnitude 10−3, due to coupling with the “solar dipole” (the motion of the Sun compared to the CMB rest frame), which are included in the data calibration by the Planck collaboration. We point out that such corrections are subject to a frequency-dependent multiplicative factor. This factor differs from unity especially at the highest frequencies, relevant for the HFI instrument. Since currently Planck calibration errors are dominated by systematics, to the point that polarization data is currently unreliable at large scales, such a correction can in principle be highly relevant for future data releases.

Planck2013 results. V. LFI calibration

We discuss the methods employed to photometrically calibrate the data acquired by the Low Frequency Instrument on Planck. Our calibration is based on a combination of the Orbital Dipole plus the Solar Dipole, caused respectively by the motion of the Planck spacecraft with respect to the Sun and by motion of the Solar System with respect to the CMB rest frame. The latter provides a signal of a few mK with the same spectrum as the CMB anisotropies and is visible throughout the mission. In this data release we rely on the characterization of the Solar Dipole as measured by WMAP. We also present preliminary results (at 44GHz only) on the study of the Orbital Dipole, which agree with the WMAP value of the Solar System speed within our uncertainties. We compute the calibration constant for each radiometer roughly once per hour, in order to keep track of changes in the detectors' gain. Since non-idealities in the optical response of the beams proved to be important, we implemented a fast convolution algorithm which considers the full beam response in estimating the signal generated by the dipole. Moreover, in order to further reduce the impact of residual systematics due to sidelobes, we estimated time variations in the calibration constant of the 30GHz radiometers (the ones with the largest sidelobes) using the signal of a reference load. We have estimated the calibration accuracy in two ways: we have run a set of simulations to assess the impact of statistical errors and systematic effects in the instrument and in the calibration procedure, and we have performed a number of consistency checks on the data and on the brightness temperature of Jupiter. Calibration errors for this data release are expected to be about 0.6% at 44 and 70 GHz, and 0.8% at 30 GHz. (Abriged.)

CMB aberration and Doppler effects as a source of hemispherical asymmetries

Our peculiar motion with respect to the CMB rest frame represents a preferred direction in the observed CMB sky since it induces an apparent deflection of the observed CMB photons (aberration) and a shift in their frequency (Doppler). Both effects distort the multipoles aℓm's at all ℓ's. Such effects are real as it has been recently measured for the first time by Planck according to what was forecast in some recent papers. However, the common lore when estimating a power spectrum from CMB is to consider that Doppler affects only the ℓ = 1 multipole, neglecting any other corrections. In this work we use simulations of the CMB sky in a boosted frame with a peculiar velocity β≡v/c = 1.23 × 10−3 in order to assess the impact of such effect on power spectrum estimations in different regions of the sky. We show that the boost induces a north-south asymmetry in the power spectrum which is highly significant and non-negligible, of about (0.58±0.10)% for half-sky cuts when going up to ℓ ≈ 2500. We suggest that these effects are relevant and may account for some of the north-south asymmetries seen in the Planck data, being especially important at small scales. Finally we analyze the particular case of the ACT experiment, which observed only a small fraction of the sky and show that it suffers a bias of about 1% on the power spectrum and of similar size on some cosmological parameters: for example the position of the peaks shifts by 0.5% and the overall amplitude of the spectrum is about 0.4% lower than a full-sky case.

Cosmic variance of the local Hubble flow in large-scale cosmological simulations

The increasing precision in the determination of the Hubble parameter has reached a per cent level at which large-scale cosmic flows induced by inhomogeneities of the matter distribution become non-negligible. Here we use large-scale cosmological N-body simulations to study statistical properties of the local Hubble parameter as measured by local observers. We show that the distribution of the local Hubble parameter depends not only on the scale of inhomogeneities, but also on how one defines the positions of observers in the cosmic web and what reference frame is used. Observers located in random dark matter haloes measure on average lower expansion rates than those at random positions in space or in the centres of cosmic voids, and this effect is stronger from the halo rest frames compared to the CMB rest frame. We compare the predictions for the local Hubble parameter with observational constraints based on type Ia supernovae (SNIa) and CMB observations. Due to cosmic variance, for observers located in random haloes we show that the Hubble constant determined from nearby SNIa may differ from that measured from the CMB by 0.8 per cent at 1sigma statistical significance. This scatter is too small to significantly alleviate a recently claimed discrepancy between current measurements assuming a flat LCDM model. However, for observers located in the centres of the largest voids permitted by the standard LCDM model, we find that Hubble constant measurements from SNIa would be biased high by 5 per cent, rendering this tension inexistent in this extreme case.

The local hole revealed by galaxy counts and redshifts

The redshifts of ~250000 galaxies are used to study the Local Hole and its associated peculiar velocities. The sample, compiled from 6dFGS and SDSS provides wide sky coverage to a depth of ~300h-1Mpc. We have therefore examined K and r limited galaxy redshift distributions and number counts to map the local density field. Comparing observed galaxy n(z) distributions to homogeneous models in three large regions of the high latitude sky, we find evidence for under-densities ranging from ~4-40% in these regions to depths of ~150h-1Mpc with the deepest under-density being over the Southern Galactic cap. Using the Galaxy and Mass Assembly (GAMA) survey we then establish the normalisation of galaxy counts at fainter magnitudes and thus confirm that the underdensity over all three fields at K<12.5 is ~15+-3%. Finally, we further use redshift catalogues to map peculiar velocities over the same areas using the average redshift - magnitude, zbar(m), technique of Soneira (1979). After accounting for the direct effect of large-scale structure on zbar(m) we can then search for peculiar velocities. Taking all three regions into consideration the data reject at the ~4sigma level the idea that we have recovered the CMB rest frame in the volume probed. There is therefore some consistent evidence from counts and Hubble diagram for a local ~150h-1Mpc underdensity that deeper counts and redshifts in the Northern Galactic cap suggest may extend to ~300h-1Mpc.

Non-Gaussianity and CMB aberration and Doppler

The peculiar motion of an observer with respect to the CMB rest frame induces a deflection in the arrival direction of the observed photons (also known as CMB aberration) and a Doppler shift in the measured photon frequencies. As a consequence, aberration and Doppler effects induce non trivial correlations between the harmonic coefficients of the observed CMB temperature maps. In this paper we investigate whether these correlations generate a bias on non-Gaussianity estimators fNL. We perform this analysis simulating a large number of temperature maps with Planck-like resolution (lmax = 2000) as different realizations of the same cosmological fiducial model (WMAP7yr). We then add to these maps aberration and Doppler effects employing a modified version of the HEALPix code. We finally evaluate a generalization of the Komatsu, Spergel and Wandelt non-Gaussianity estimator for all the simulated maps, both when peculiar velocity effects have been considered and when these phenomena have been neglected. Using the value v/c = 1.23 × 10−3 for our peculiar velocity, we found that the aberration/Doppler induced non-Gaussian signal is at most of about half of the cosmic variance σ for fNL both in a full-sky and in a cut-sky experimental configuration, for local, equilateral and orthogonal estimators. We conclude therefore that when estimating fNL it is safe to ignore aberration and Doppler effects if the primordial map is already Gaussian. More work is necessary however to assess whether a map which contains non-Gaussianity can be significantly distorted by a peculiar velocity.

Cosmological parameter estimation: impact of CMB aberration

The peculiar motion of an observer with respect to the CMB rest frame induces an apparent deflection of the observed CMB photons, i.e. aberration, and a shift in their frequency, i.e. Doppler effect. Both effects distort the temperature multipoles aℓm's via a mixing matrix at any ℓ. The common lore when performing a CMB based cosmological parameter estimation is to consider that Doppler affects only the l = 1 multipole, and neglect any other corrections. In this paper we reconsider the validity of this assumption, showing that it is actually not robust when sky cuts are included to model CMB foreground contaminations. Assuming a simple fiducial cosmological model with five parameters, we simulated CMB temperature maps of the sky in a WMAP-like and in a Planck-like experiment and added aberration and Doppler effects to the maps. We then analyzed with a MCMC in a Bayesian framework the maps with and without aberration and Doppler effects in order to assess the ability of reconstructing the parameters of the fiducial model. We find that, depending on the specific realization of the simulated data, the parameters can be biased up to one standard deviation for WMAP and almost two standard deviations for Planck. Therefore we conclude that in general it is not a solid assumption to neglect aberration in a CMB based cosmological parameter estimation.

Measuring our peculiar velocity on the CMB with high-multipole off-diagonal correlations

Our peculiar velocity with respect to the CMB rest frame is knownto induce a large dipole in the CMB. However, the motion of an observerhas also the effect of distorting the anisotropies at all scales,as shown by Challinor and Van Leeuwen (2002), due to aberration andDoppler effects. We propose to measure independently our local motionby using off-diagonal two-point correlation functions for high multipoles.We study the observability of the signal for temperature and polarizationanisotropies. We point out that Planck can measure the velocityβ with an error of about 30% and the direction with anerror of about 20°. This method constitutes a cross-check,which can be useful to verify that our CMB dipole is due mainly toour velocity or to disentangle the velocity from other possible intrinsicsources.Although in this paper we focus on our peculiar velocity, a similareffect would result also from other intrinsic vectorial distortion ofthe CMB which would induce a dipolar lensing. Measuringthe off-diagonal correlation terms is therefore a test for a preferreddirection on the CMB sky.

Probing the anisotropic local Universe and beyond with SNe Ia data

The question of the transition to global isotropy from our anisotropic local Universe is studied using the Union 2 catalogue of Type Ia supernovae (SNe Ia). We construct a "residual" statistic sensitive to systematic shifts in their brightness in different directions and use this to search in different redshift bins for a preferred direction on the sky in which the SNe Ia are brighter or fainter relative to the 'standard' LCDM cosmology. At low redshift (z<0.05) we find that an isotropic model such as LCDM is barely consistent with the SNe Ia data at 2-3 sigma. A complementary maximum likelihood analysis of peculiar velocities confirms this finding -- there is a bulk flow of around 260 km/sec at z \sim 0.06, which disagrees with LCDM at 1-2 sigma. Since the Shapley concentration is believed to be largely responsible for this bulk flow, we make a detailed study of the infall region: the SNe Ia falling away from the Local Group towards Shapley are indeed significantly dimmer than those falling towards us and on to Shapley. Convergence to the CMB rest frame must occur well beyond Shapley (z>0.06) so the low redshift bulk flow can systematically bias any reconstruction of the expansion history of the Universe. At high redshifts z>0.15 the agreement between the SNe Ia data and the isotropic LCDM model does improve, however, the sparseness and low quality of the data means that LCDM cannot be singled out as the preferred cosmological model.

Neutrino oscillations,Lorentz/CPTviolation, and dark energy

If dark energy (DE) couples to neutrinos, then there may be apparent violations of Lorentz/CPT invariance in neutrino oscillations. The DE-induced Lorentz/CPT violation takes a specific form that introduces neutrino oscillations that are energy independent, differ for particles and antiparticles, and can lead to novel effects for neutrinos propagating through matter. We show that ultra-high-energy neutrinos may provide one avenue to seek this type of Lorentz/CPT violation in \nu_\mu-\nu_\tau oscillations, improving the current sensitivity to such effects by seven orders of magnitude. Lorentz/CPT violation in electron-neutrino oscillations may be probed with the zenith-angle dependence for high-energy atmospheric neutrinos. The ``smoking gun,'' for DE-neutrino coupling would, however, be a dependence of neutrino oscillations on the direction of the neutrino momentum relative to our peculiar velocity with respect to the CMB rest frame. While the amplitude of this directional dependence is expected to be small, it may nevertheless be worth seeking in current data and may be a target for future neutrino experiments.

The Velocity Field of the Local Universe from Measurements of Type Ia Supernovae

We present a measurement of the velocity flow of the local universe relative to the CMB rest frame, based on the Jha, Riess & Kirshner (2007) sample of 133 low redshift type Ia supernovae. At a depth of 4500 km s{sup -1} we find a dipole amplitude of 279 {+-} 68 km s{sup -1} in the direction l = 285{sup o} {+-} 18{sup o}, b = -10{sup o} {+-} 15{sup o}, consistent with earlier measurements and with the assumption that the local velocity field is dominated by the Great Attractor region. At a larger depth of 5900 km s{sup -1} we find a shift in the dipole direction towards the Shapley concentration. We also present the first measurement of the quadrupole term in the local velocity flow at these depths. Finally, we have performed detailed studies based on N-body simulations of the expected precision with which the lowest multipoles in the velocity field can be measured out to redshifts of order 0.1. Our mock catalogues are in good agreement with current observations, and demonstrate that our results are robust with respect to assumptions about the influence of local environment on the type Ia supernova rate.

DARK ENERGY IN MOTION

Recent large-scale peculiar velocity surveys suggest that large matter volumes could be moving with appreciable velocity with respect to the CMB rest frame. If confirmed, such results could conflict with the Cosmological Principle according to which the matter and CMB rest frames should converge on very large scales. In this work, we explore the possibility that such large-scale bulk flows are due, not to the motion of matter with respect to the CMB, but to the flow of dark energy with respect to matter. Indeed, when dark energy is moving, the usual definition of the CMB rest frame as that in which the CMB dipole vanishes is not appropriate. We find instead that the dipole vanishes for observers at rest with respect to the cosmic center of mass, i.e. in motion with respect to the background radiation.

The expected dipole in the distribution of cosmological gamma-ray bursts

view Abstract Citations (14) References (10) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Expected Dipole in the Distribution of Cosmological gamma -Ray Bursts Maoz, Eyal Abstract If γ-ray bursts originate at cosmological distances then their angular distribution should exhibit a dipole in the direction of the solar motion relative to the cosmic microwave background. This is due to the combined effects of aberration, an anisotropic shift of the burst event rate, and an angular variation in the distance out to which bursts can be detected. We derive the amplitude of the expected dipole for an {OMEGA}_0_ <= 1 cosmological model, and for various possible evolution rates of the burst population. Although our dimensionless velocity with respect to the CMB rest frame is of order 10^-3^, the dipole amplitude is of order 10^-2^, an order of magnitude larger. The results depend very weakly on the value of {OMEGA}_0_, but are sensitive to the spectral index of the bursts' photon spectra, and to the rate of evolution of the burst population. There is no dependence on the value of the Hubble constant. A clear detection of the dipole will require a larger sample of γ-ray bursts than currently available (of order 10^4^ bursts). Future statistical analyses of the hypothesis that bursts originate at cosmological distances should take this effect into account, rather than assuming a perfectly isotropic distribution, for obtaining the correct statistical significance of their results. Publication: The Astrophysical Journal Pub Date: June 1994 DOI: 10.1086/174258 arXiv: arXiv:astro-ph/9307039 Bibcode: 1994ApJ...428..454M Keywords: Amplitudes; Cosmology; Dipole Moments; Evolution (Development); Expectation; Gamma Ray Bursts; Luminosity; Angular Distribution; Anisotropy; Background Radiation; Frames; Microwaves; Rates (Per Time); Red Shift; Astronomy; COSMOLOGY: OBSERVATIONS; GAMMA RAYS: BURSTS; Astrophysics E-Print: 10 pages, Latex, Submitted to ApJ, preprints available full text sources arXiv | ADS |

Dipole Anisotropy in the COBE Differential Microwave Radiometers First-Year Sky Maps

view Abstract Citations (374) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Dipole Anisotropy in the COBE Differential Microwave Radiometers First-Year Sky Maps Kogut, A. ; Lineweaver, C. ; Smoot, G. F. ; Bennett, C. L. ; Banday, A. ; Boggess, N. W. ; Cheng, E. S. ; de Amici, G. ; Fixsen, D. J. ; Hinshaw, G. ; Jackson, P. D. ; Janssen, M. ; Keegstra, P. ; Loewenstein, K. ; Lubin, P. ; Mather, J. C. ; Tenorio, L. ; Weiss, R. ; Wilkinson, D. T. ; Wright, E. L. Abstract We present a determination of the cosmic microwave background dipole amplitude and direction from the COBE Differential Microwave Radiometers (DMR) first year of data. Data from the six DMR channels are consistent with a Doppler-shifted Planck function of dipole amplitude ΔT = 3.365±0.027 mK toward direction (lII, bII) = (264°.4±0°.3, 48°.4±0°.5). The implied velocity of the Local Group with respect to the CMB rest frame is υLG = 627±22 km s-1 toward (lII, bII) = (276°±3°, 30°±3°). DMR has also mapped the dipole anisotropy resulting from the Earth's orbital motion about the Solar system barycenter, yielding a measurement of the monopole CMB temperature T0 at 31.5, 53, and 90 GHz, T0 = 2.75±0.05 K. Publication: The Astrophysical Journal Pub Date: December 1993 DOI: 10.1086/173453 arXiv: arXiv:astro-ph/9312056 Bibcode: 1993ApJ...419....1K Keywords: COSMOLOGY: COSMIC MICROWAVE BACKGROUND; COSMOLOGY: OBSERVATIONS; Astrophysics E-Print: Post Script (4 figures) Ap J 419, 1-6 (1993) full text sources arXiv | ADS | data products SIMBAD (1)