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相关论文: Venus Observations at 40 and 90 GHz with CLASS

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Measurements are reported of the yield and spectrum of fluorescence, excited by a 28.5 GeV electron beam, in air at a range of pressures of interest to ultra-high energy cosmic ray detectors. The wavelength range was 300 - 420 nm. System…

The transit of Venus in 2004 offered the rare possibility to remotely sense a well-known planetary atmosphere using ground-based observations for absorption spectroscopy. Transmission spectra of Venus' atmosphere were obtained in the near…

地球与行星天体物理 · 物理学 2015-05-28 P. Hedelt , R. Alonso , T. Brown , M. Collados Vera , H. Rauer , H. Schleicher , W. Schmidt , F. Schreier , R. Titz

Many observers in the past gave detailed descriptions of the telescopic aspect of Venus during its extremely rare transits across the Solar disk. In particular, at the ingress and egress, the portion of the planet's disk outside the Solar…

地球与行星天体物理 · 物理学 2015-06-03 P. Tanga , Th. Widemann , B. Sicardy , J. M. Pasachoff , J. Arnaud , L. Comolli , A. Rondi , S. Rondi , P. Suetterlin

The absolute temperature of the cosmic microwave background (CMB) has been measured at a frequency of 1280 MHz. The observation was made with a modified version of the L-band receiver used in the Giant Metre wavelength Radio Telescope…

天体物理学 · 物理学 2007-05-23 A. Raghunathan , R. Subrahmanyan

A defining characteristic of the planet Venus is its thick, CO2-dominated atmosphere. Despite over fifty years of robotic exploration, including thirteen successful atmosphere probes and landers, our knowledge of N2, the…

地球与行星天体物理 · 物理学 2019-11-15 Patrick N. Peplowski , David J. Lawrence , Jack T. Wilson

Venus Express provided a long-term monitoring of Venus atmosphere. Several works focused on the dynamics of the upper cloud visible on the day-side in ultraviolet images sensitive to the 65-70 km altitude and in the lower cloud level (50 km…

地球与行星天体物理 · 物理学 2024-01-31 Ricardo Hueso , Javier Peralta , Itziar Garate-Lopez , Tatyana V. Bandos , Agustin Sanchez-Lavega

ALMA observations of the Sun at mm-$\lambda$ offer a unique opportunity to investigate the temperature structure of the solar chromosphere. In this article we expand our previous work on modeling the chromospheric temperature of the quiet…

太阳与恒星天体物理 · 物理学 2020-08-19 C. E. Alissandrakis , A. Nindos , T. S. Bastian , S. Patsourakos

UV absorption cross sections are an essential ingredient of photochemical atmosphere models. Exoplanet searches have unveiled a large population of short-period objects with hot atmospheres, very different from what we find in our solar…

The detection of phosphine (PH3) in the atmosphere of Venus has been recently reported based on millimeter-wave radio observations (Greaves et al. 2020), and its re-analyses (Greaves et al. 2021a/b). In this Matters Arising we perform an…

At frequencies close to 1 GHz the sky diffuse radiation is a superposition of radiation of Galactic origin, the 3 K Relic or Cosmic Microwave Background Radiation, and the signal produced by unresolved extragalactic sources. Because of…

天体物理学 · 物理学 2014-11-18 M. Zannoni , A. Tartari , M. Gervasi , G. Boella , G. Sironi , A. De Lucia , A. Passerini

In this study, we analyzed millimeter-wave data toward the quasar PKS1830-211 observed with the Atacama Large Millimeter/submillimeter Array to obtain absorption spectra of HCN $J$=2-1, $J$=3-2, $J$=4-3, and $J$=5-4 lines at the…

宇宙学与河外天体物理 · 物理学 2025-09-26 Tatsuya Kotani , Tomoharu Oka , Rei Enokiya , Kazuki Yanagihara , Miyuki Kaneko , Ryo Ariyama

Planetary-scale waves at the Venusian cloud-top cause periodic variations in both winds and ultraviolet (UV) brightness. While the wave candidates are the 4-day Kelvin wave and 5-day Rossby wave with zonal wavenumber 1, their temporal…

The planets Uranus and Neptune with small apparent diameters are primary calibration standards. We investigate their variability at ~90 GHz using archived data taken at the IRAM 30m telescope during the 20 years period 1985 to 2005. We…

天体物理学 · 物理学 2009-11-13 C. Kramer , R. Moreno , A. Greve

The knowledge of the Venus near-surface atmosphere is sparse. Few spacecrafts landed on the surface and measured winds with amplitudes below 1 m/s. The diurnal cycle of the wind amplitude and orientation is not known. Recent numerical…

地球与行星天体物理 · 物理学 2025-10-20 Maxence Lefèvre , Sébastien Lebonnois , Aymeric Spiga , François Forget

We examine the brightness of the Cosmic Radio Background (CRB) by comparing the contribution from individual source counts to absolute measurements. We use a compilation of radio counts to estimate the contribution of detected sources to…

宇宙学与河外天体物理 · 物理学 2015-05-27 Tessa Vernstrom , Douglas Scott , Jasper Wall

Searches for phosphine in Venus' atmosphere have sparked a debate. Cordiner et al. 2022 analyse spectra from the Stratospheric Observatory For Infrared Astronomy (SOFIA) and infer <0.8 ppb of PH3. We noticed that some spectral artefacts…

地球与行星天体物理 · 物理学 2023-12-13 Jane S. Greaves , Janusz J. Petkowski , Anita M. S. Richards , Clara Sousa-Silva , Sara Seager , David L. Clements

We present spatially resolved millimeter maps of Neptune between 95 and 242 GHz taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in $2016-2017$. The millimeter weighting functions peak between 1 and 10 bar on Neptune,…

地球与行星天体物理 · 物理学 2019-07-17 Joshua Tollefson , Imke de Pater , Statia Luszcz-Cook , David DeBoer

We conduct a stacking analysis using 1.4 GHz NRAO VLA Sky Survey (NVSS) detections and Planck all-sky maps to estimate the differential source counts down to the few 100 $\mu$Jy level at 30, 44, 70 and 100 GHz. Consequently, we are able to…

星系天体物理 · 物理学 2018-07-11 Eric J. Murphy , Ranga-Ram Chary

We investigate statistical and individual astrophysical properties of active galactic nuclei (AGNs), such as parsec-scale flux density, core dominance, angular and linear sizes, maximum observed brightness temperatures of VLBI core…

宇宙学与河外天体物理 · 物理学 2015-03-20 A. B. Pushkarev , Y. Y. Kovalev