Search Publications

Growth history and quasar bias evolution at z < 3 from Quaia
DOI: 10.1088/1475-7516/2024/06/012 Bibcode: 2024JCAP...06..012P

Alonso, David; Carron, Julien; Lewis, Antony +4 more

We make use of the Gaia-unWISE quasar catalogue, Quaia, to constrain the growth history out to high redshifts from the clustering of quasars and their cross-correlation with maps of the Cosmic Microwave Background (CMB) lensing convergence. Considering three tomographic bins, centred at redshifts z̅i = [0.69, 1.59, 2.72], we reconstruct …

2024 Journal of Cosmology and Astroparticle Physics
Gaia 11
The Rise of the r-process in the Gaia-Sausage/Enceladus Dwarf Galaxy
DOI: 10.3847/1538-4357/ad6f9b Bibcode: 2024ApJ...974..232O

Naidu, Rohan P.; Frebel, Anna; Limberg, Guilherme +2 more

Neutron star mergers (NSMs) produce r-process elements after a time-delayed inspiral process. Once a significant number of NSMs are present in a galaxy, r-process elements, such as Eu, are expected to significantly increase with time. Yet, there have been limited observational data in support of Eu increasing within Local Group galaxies. We have o…

2024 The Astrophysical Journal
Gaia 11
High-redshift JWST massive galaxies and the initial clustering of supermassive primordial black holes
DOI: 10.1103/PhysRevD.110.103540 Bibcode: 2024PhRvD.110j3540H

Piao, Yun-Song; Huang, Hai-Long; Jiang, Jun-Qian

In this paper, we show that the initial clustering of supermassive primordial black holes (SMPBHs) beyond a Poisson distribution can efficiently enhance the matter power spectrum, and thus the halo mass function. As a result, the population of initially clustered SMPBHs with M

2024 Physical Review D
JWST 11
Chemical Mapping of Temperate Sub-Neptune Atmospheres: Constraining the Deep Interior H2O/H2 Ratio from the Atmospheric CO2/CH4 Ratio
DOI: 10.3847/2041-8213/ad6b25 Bibcode: 2024ApJ...971L..48Y

Yang, Jeehyun; Hu, Renyu

Understanding the planetary envelope composition of sub-Neptune-type exoplanets is challenging due to the inherent degeneracy in their interior composition scenarios. Particularly, the planetary envelope's H2O/H2 ratio, which can also be expressed as the O/H ratio, provides crucial insights into its original location relative…

2024 The Astrophysical Journal
JWST 11
A Deep uGMRT View of the Ultra-steep Spectrum Radio Halo in A521
DOI: 10.3847/1538-4357/ad1190 Bibcode: 2024ApJ...962...40S

Brunetti, G.; Santra, R.; Kale, R. +8 more

We present the first detailed analysis of the ultra-steep spectrum radio halo in the merging galaxy cluster A521, based on upgraded Giant Metrewave Radio telescope observations. The combination of radio observations (300–850 MHz) and archival X-ray data provides a new window into the complex physics occurring in this system. When compared to all p…

2024 The Astrophysical Journal
XMM-Newton 11
Enrichment by extragalactic first stars in the Large Magellanic Cloud
DOI: 10.1038/s41550-024-02223-w Bibcode: 2024NatAs...8..637C

Li, Ting S.; Frebel, Anna; Simon, Joshua D. +8 more

The Large Magellanic Cloud (LMC) is the Milky Way's most massive satellite galaxy, which only recently (~2 billion years ago) fell into our Galaxy. As stellar atmospheres preserve the composition of their natal cloud, the LMC's recent infall makes its most ancient, metal-deficient (`low-metallicity') stars unique windows into early star formation …

2024 Nature Astronomy
Gaia 11
What Is the Black Hole Spin in Cyg X-1?
DOI: 10.3847/2041-8213/ad43ed Bibcode: 2024ApJ...967L...9Z

Zdziarski, Andrzej A.; Szanecki, Michał; Dewangan, Gulab +6 more

We perform a detailed study of the black hole spin of Cyg X-1, using accurate broadband X-ray data obtained in the soft spectral state by simultaneous NICER and NuSTAR observations, supplemented at high energies by INTEGRAL data. We use the relativistic disk model kerrbb together with different models of the Comptonization high-energy tail and the…

2024 The Astrophysical Journal
INTEGRAL 11
X-Shooting ULLYSES: Massive stars at low metallicity: IV. Spectral analysis methods and exemplary results for O stars
DOI: 10.1051/0004-6361/202449829 Bibcode: 2024A&A...689A..30S

Bouret, J. -C.; Martins, F.; Hillier, D. J. +26 more

Context. The spectral analysis of hot, massive stars is a fundamental astrophysical method of determining their intrinsic properties and feedback. With their inherent, radiation-driven winds, the quantitative spectroscopy for hot, massive stars requires detailed numerical modeling of the atmosphere and an iterative treatment in order to obtain the…

2024 Astronomy and Astrophysics
XMM-Newton eHST 11
Alfvénic fluctuations in the expanding solar wind: Formation and radial evolution of spherical polarization
DOI: 10.1063/5.0177754 Bibcode: 2024PhPl...31c2901M

Hellinger, P.; Matteini, L.; Horbury, T. S. +7 more

We investigate properties of large-scale solar wind Alfvénic fluctuations and their evolution during radial expansion. We assume a strictly radial background magnetic field B ∥ R, and we use two-dimensional hybrid (fluid electrons, kinetic ions) simulations of balanced Alfvénic turbulence in the plane orthogonal to B; the simulated plasma evolves …

2024 Physics of Plasmas
Ulysses 11
Cosmic evolution early release science survey (CEERS): multiclassing galactic dwarf stars in the deep JWST/NIRCam
DOI: 10.1093/mnras/stae316 Bibcode: 2024MNRAS.529.1067H

Papovich, Casey; Finkelstein, Steven L.; Burgarella, Denis +20 more

Low-mass (sub)stellar objects represent the low end of the initial mass function, the transition to free-floating planets and a prominent interloper population in the search for high-redshift galaxies. To what accuracy can photometry only classify these? JWST/NIRCam has several advantages over Hubble Space Telescope (HST)/WFC3 near-infrared (NIR):…

2024 Monthly Notices of the Royal Astronomical Society
eHST JWST 11