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Lithium is an important element for the understanding of ultracool dwarfs because it is lost to fusion at masses above $\sim 68\, M_{\rm J}$. Hence, the presence or absence of atomic Li has served as an indicator of the nearby H-burning…

Solar and Stellar Astrophysics · Physics 2021-09-29 Ehsan Gharib-Nezhad , Mark S. Marley , Natasha E. Batalha , Channon Visscher , Richard S. Freedman , Roxana E. Lupu

Vertically pointing Doppler radar has been used to study the evolution of ice particles as they sediment through a cirrus cloud. The measured Doppler fall speeds, together with radar-derived estimates for the altitude of cloud top, are used…

Atmospheric and Oceanic Physics · Physics 2015-06-26 C. D. Westbrook , R. J. Hogan , A. J. Illingworth , E. J. O'Connor

We describe optical methods for trapping, cooling, and observing single $^{87}$Rb atoms in a four-lens "Maltese cross" geometry (MCG). The use of four high numerical-aperture lenses in the cardinal directions enables efficient collection of…

Atomic Physics · Physics 2021-03-11 Lorena C. Bianchet , Natalia Alves , Laura Zarraoa , Natalia Bruno , Morgan W. Mitchell

Studying a range of old metal-poor stars provides information over cosmological timescales of our Galaxy. Such studies are indicative of the pristine gases and evolution of the Milky Way. Deriving stellar parameters and abundances from…

Solar and Stellar Astrophysics · Physics 2015-06-12 Camilla. J. Hansen

Understanding the origin of the astonishing diversity of exoplanets is a key question for the coming decades. ALMA has revolutionized our view of the dust emission from protoplanetary disks, demonstrating the prevalence of ring and spiral…

We demonstrate the trapping of cold $^{87}Rb$ atoms in a toroidal geometry using a radio frequency (rf) dressed quadrupole magnetic trap formed by superposing a strong rf-field on a quadrupole trap. This rf-dressed quadrupole trap has the…

Quantum Physics · Physics 2017-02-16 A. Chakraborty , S. R. Mishra , S. P. Ram , S. K. Tiwari , H. S. Rawat

Glacier modeling is crucial for quantifying the evolution of cryospheric processes. At the same time, uncertainties hamper process understanding and predictive accuracy. Here, we suggest improving glacier mass balance simulations for the…

We performed a uniform and detailed analysis of 1112 high-resolution spectra of FGK dwarfs obtained with the HARPS spectrograph at the ESO 3.6 m telescope (La Silla, Chile). Most stars have effective temperatures 4700 K < Teff < 6300 K and…

Astrophysics of Galaxies · Physics 2011-11-22 V. Zh. Adibekyan , N. C. Santos , S. G. Sousa , G. Israelian

We have developed a new method of multi-wavelength data combination for the search of late-type radio dwarfs, and have put it into practice using GLEAM-X DR1 data. The initial sample is selected by cross-matching the Gaia/DR3 objects with…

Solar and Stellar Astrophysics · Physics 2024-10-30 Qichen Huang , Biwei Jiang , Zehao Zhang , Albert Zijlstra

The North Greenland Ice Core Project (NorthGRIP) provides paleoclimatic information back to at about 120 kyr before present (Dahl-Jensen and others, 2002). Each year, precipitation on the ice sheet covers it with a new layer of snow, which…

The application of atom probe tomography (APT) to frozen liquids is limited by difficulties in specimen preparation. Here, we report on the use of nanoporous Cu needles as a physical framework to hold water ice for investigation using APT.…

We present new atomic data (radiative transitions rates and collision strengths) from large scale calculations and a non-LTE spectral model for Fe III. This model is in very good agreement with observed astronomical emission spectra, in…

Atomic Physics · Physics 2015-05-19 Manuel A. Bautista , Connor P. Ballance , Pascal Quinet

We present a catalog of 8545 and 19,257 unique DA white dwarfs observed in SDSS Data Release 19 and previous SDSS data releases, respectively. This is the largest catalog of both spectroscopic and photometric measurements of DA white dwarfs…

Statistical inference in observational science typically relies on a fundamental assumption: as sample size increases and uncertainties decrease, the inferred results should converge to the true physical quantities. This assumption…

Machine Learning · Computer Science 2026-05-01 Zhipeng Zhang

High resolution, high S/N spectra have been obtained for a sample of 90 F and G main-sequence disk stars covering the metallicity range -1.0 < [Fe/H] < +0.1, and have been analysed in a parallel way to the work of Edvardsson et al. (1993).…

Astrophysics · Physics 2009-10-31 Y. Q. Chen , P. E. Nissen , G. Zhao , H. W. Zhang , T. Benoni

We present a series of systematic abundance measurements for 89 hydrogen atmosphere (DA-type) white dwarfs with temperatures spanning 16000-77000K drawn from the FUSE spectral archive. This is the largest study to date of white dwarfs where…

Solar and Stellar Astrophysics · Physics 2015-06-18 M. A. Barstow , J. K. Barstow , S. L. Casewell , J. B. Holberg , I. Hubeny

The more than 200,000 glaciers outside the ice sheets play a crucial role in our society by influencing sea-level rise, water resource management, natural hazards, biodiversity, and tourism. However, only a fraction of these glaciers…

Computer Vision and Pattern Recognition · Computer Science 2025-02-03 Codruţ-Andrei Diaconu , Konrad Heidler , Jonathan L. Bamber , Harry Zekollari

Recent studies of radio data put strong constraints on annihilation cross section for dark matter. In this article, we provide the first analysis of using M33 radio data in constraining annihilating dark matter. The resulting constraints of…

High Energy Astrophysical Phenomena · Physics 2017-10-24 Man Ho Chan

We report on the structure of the nuclear star cluster in the innermost 0.16 pc of the Galaxy as measured by the number density profile of late-type giants. Using laser guide star adaptive optics in conjunction with the integral field…

Astrophysics of Galaxies · Physics 2015-05-13 Tuan Do , Andrea M. Ghez , Mark R. Morris , Jessica R. Lu , Keith Matthews , Sylvana Yelda , James Larkin

Gas mass remains one of the most difficult protoplanetary disk properties to constrain. With much of the protoplanetary disk too cold for the main gas constituent, H2, to emit, alternative tracers such as dust, CO, or the H2 isotopolog HD…