Discovery of spherules of likely extrasolar composition in the Pacific Ocean site of the CNEOS 2014-01-08 (IMI) bolide

By: Abraham Loeb, Toby Adamson, Sophie Bergstrom, Richard Cloete, Shai Cohen, Kevin Conrad, Laura Domine, Hairuo Fu, Charles Hoskinson, Eugenia Hyung, Stein Jacobsen, Mike Kelly, Jason Kohn, Edwin Lard, Sebastian Lam, Frank Laukien, Jim Lem, Rob McCallum, Rob Millsap, Christopher Parendo, Michail Pataev, Chaitanya Peddeti, Jeff Pugh, Shmuel Samuha, Dimitar Sasselov, Max Schlereth, J.J. Siler, Amir Siraj, Peter Mark Smith, Roald Tagle, Jonathan Taylor, Ryan Weed, Art Wright, Jeff Wynn

We have conducted an extensive towed-magnetic-sled survey during the period 14-28 June, 2023, over the seafloor about 85 km north of Manus Island, Papua New Guinea, and found about 700 spherules of diameter 0.05-1.3 millimeters in our samples, of which 57 were analyzed so far. Approximately 0.26 km2 of seafloor was sampled in this survey, centered around the calculated path of the bolide CNEOS 2014-01-08 (IMI) with control areas north and sou... more
We have conducted an extensive towed-magnetic-sled survey during the period 14-28 June, 2023, over the seafloor about 85 km north of Manus Island, Papua New Guinea, and found about 700 spherules of diameter 0.05-1.3 millimeters in our samples, of which 57 were analyzed so far. Approximately 0.26 km2 of seafloor was sampled in this survey, centered around the calculated path of the bolide CNEOS 2014-01-08 (IMI) with control areas north and south of that path. The 5 spherules, significantly concentrated along the expected meteor path, were retrieved from seafloor depths ranging between 1.5-2.2 km. Mass spectrometry of 47 spherules near the high-yield regions along IMI's path reveals a distinct extra-solar abundance pattern for 5 of them, while background spherules have abundances consistent with a solar system origin. The unique spherules show an excess of Be, La and U, by up to three orders of magnitude relative to the solar system standard of CI chondrites. These "BeLaU"-type spherules, never seen before, also have very low refractory siderophile elements such 10 as Re. Volatile elements, such as Mn, Zn, Pb, are depleted as expected from evaporation losses during a meteor's airburst. In addition, the mass-dependent variations in 57Fe/54Fe and 56Fe/54Fe are also consistent with evaporative loss of the light isotopes during the spherules' travel in the atmosphere. The "BeLaU" abundance pattern is not found in control regions outside of IMI's path and does not match commonly manufactured alloys or natural meteorites in the solar system. This evidence points towards an association of "BeLaU"-type spherules with IM1, supporting its interstellar origin independently of the high 15 velocity and unusual material strength implied from the CNEOS data. We suggest that the "BeLaU" abundance pattern could have originated from a highly differentiated magma ocean of a planet with an iron core outside the solar system or from more exotic sources. less
Statistical strong lensing. I. Constraints on the inner structure of galaxies from samples of a thousand lenses

By: Alessandro Sonnenfeld

Context. The number of known strong gravitational lenses is expected to grow substantially in the next few years. The combination of large samples of lenses has the potential to provide strong constraints on the inner structure of galaxies. Aims: We investigate the extent to which we can calibrate stellar mass measurements and constrain the average dark matter density profile of galaxies by combining strong lensing data from thousands of lens... more
Context. The number of known strong gravitational lenses is expected to grow substantially in the next few years. The combination of large samples of lenses has the potential to provide strong constraints on the inner structure of galaxies. Aims: We investigate the extent to which we can calibrate stellar mass measurements and constrain the average dark matter density profile of galaxies by combining strong lensing data from thousands of lenses. Methods: We generated mock samples of axisymmetric lenses. We assume that, for each lens, we have measurements of two image positions of a strongly lensed background source, as well as magnification information from full surface brightness modelling, and a stellar-population-synthesis-based estimate of the lens stellar mass. We then fitted models describing the distribution of the stellar population synthesis mismatch parameter αsps (the ratio between the true stellar mass and the stellar-population-synthesis-based estimate) and the dark matter density profile of the population of lenses to an ensemble of 1000 mock lenses. Results: We obtain the average αsps, projected dark matter mass, and dark matter density slope with greater precision and accuracy compared with current constraints. A flexible model and knowledge of the lens detection efficiency as a function of image configuration are required in order to avoid a biased inference. Conclusions: Statistical strong lensing inferences from upcoming surveys provide a way to calibrate stellar mass measurements and to constrain the inner dark matter density profile of massive galaxies. less
7 SciCasts by Alessandro Sonnenfeld.
The Temperature of Hot Gas in the Universe

By: Eiichiro Komatsu; Yi-Kuan Chiang; Ryu Makiya; Brice Ménard

How hot is the Universe today? How hot was it before? We report on the result of the observational determination of the mean temperature of hot gas in the Universe. We find that the mean gas temperature has increased ten times over the last 8 billion years, to reach about 2 million Kelvin today. As cosmic structures form, matter density fluctuations collapse gravitationally and baryonic matter is shock-heated and thermalized. We therefore exp... more
How hot is the Universe today? How hot was it before? We report on the result of the observational determination of the mean temperature of hot gas in the Universe. We find that the mean gas temperature has increased ten times over the last 8 billion years, to reach about 2 million Kelvin today. As cosmic structures form, matter density fluctuations collapse gravitationally and baryonic matter is shock-heated and thermalized. We therefore expect a connection between the mean gravitational potential energy of collapsed halos and the mean thermal energy of baryons. Our result provides quantitative verification of such a connection via cosmic shock-heating. less
Cosmic Birefringence in 2022

By: Patricia Diego-Palazuelos; Johannes R. Eskilt; Eiichiro Komatsu

The observed pattern of linear polarization of the cosmic microwave background (CMB) photons is a sensitive probe of physics violating parity symmetry under inversion of spatial coordinates. A new parity-violating interaction might have rotated the plane of linear polarization by an angle β as the CMB photons have been traveling for more than 13 billion years. This effect is known as "cosmic birefringence." In this paper, we present new measu... more
The observed pattern of linear polarization of the cosmic microwave background (CMB) photons is a sensitive probe of physics violating parity symmetry under inversion of spatial coordinates. A new parity-violating interaction might have rotated the plane of linear polarization by an angle β as the CMB photons have been traveling for more than 13 billion years. This effect is known as "cosmic birefringence." In this paper, we present new measurements of cosmic birefringence from a joint analysis of polarization data from two space missions, Planck and WMAP. This dataset covers a wide range of frequencies from 23 to 353 GHz. We measure β=0.342°+0.094°−0.091° (68% C.L.) for nearly full-sky data, which excludes β=0 at 99.987% C.L. This corresponds to the statistical significance of 3.6σ. There is no evidence for frequency dependence of β. We find a similar result, albeit with a larger uncertainty, when removing the Galactic plane from the analysis. less