Results 91 to 100 of about 1,899,768 (248)

WISE morphological study of Wolf-Rayet nebulae [PDF]

open access: yes, 2015
We present a morphological study of nebulae around Wolf-Rayet (WR) stars using archival narrow-band optical and Wide-field Infrared Survey Explorer (WISE) infrared images. The comparison among WISE images in different bands and optical images proves to be a very efficient procedure to identify the nebular emission from WR nebulae, and to disentangle it
arxiv   +1 more source

Effect of Organic Farming on Soil Carbon Reserves and Quality in Citrus Groves in the Brazilian Semi‐Arid Region

open access: yesSoil Use and Management, Volume 41, Issue 2, April 2025.
ABSTRACT Organic fertilisation of orchard soils can influence soil organic matter (SOM), nutrient cycling, greenhouse gas emissions and the overall sustainability of the farming systems. This study investigated the long‐term effects of organic citrus farming on soil properties in a semi‐arid region of Ceará, Brazil.
David Gabriel Campos Pereira   +4 more
wiley   +1 more source

ON CALIBRATIONS USING THE CRAB NEBULA AND MODELS OF THE NEBULAR X-RAY EMISSION [PDF]

open access: yes, 2010
Motivated by a paper of Kirsch et al. on possible use of the Crab Nebula as a standard candle for calibrating X-ray response functions, we examine consequences of intrinsic departures from a single (absorbed) power law upon such calibrations.
M. Weisskopf   +7 more
semanticscholar   +1 more source

Kinematics of Molecular Hydrogen Emission from Planetary and Pre-planetary Nebulae [PDF]

open access: yesarXiv, 2000
We report results from a program of high-resolution spectral mapping of rotational H_2 emission from bipolar planetary and pre-planetary nebulae. Long-slit spectra obtained with the NOAO Phoenix near-infrared spectrometer allow us to probe the molecular kinematics of these nebulae at moderate spatial resolution.
arxiv  

A CO Survey of Young Planetary Nebulae [PDF]

open access: yes, 2005
We report the results of a sensitive survey of young planetary nebulae in the CO J=2-1 line that significantly increases the available data on warm, dense, molecular gas in the early phases of planetary nebula formation. The observations were made using the IRAM 30 m telescope with the 3 by 3 pixel Heterodyne Receiver Array (HERA).
arxiv   +1 more source

A primitive asteroid that lived fast and died young sampled by a xenolith in the Cold Bokkeveld CM2 carbonaceous chondrite

open access: yesMeteoritics &Planetary Science, Volume 60, Issue 3, Page 464-483, March 2025.
Abstract Xenoliths in carbonaceous chondrites include lithologies that are unrepresented in the meteorite record and so are a rich source of information on asteroid diversity. Cold Bokkeveld is a CM2 regolith breccia that contains both hydrous and anhydrous lithic clasts. Here, we describe a hydrous clast with a fine‐grained rim.
Martin R. Lee   +3 more
wiley   +1 more source

Observations of the planetary nebula RWT 152 with OSIRIS/GTC [PDF]

open access: yes, 2016
RWT 152 is one of the few known planetary nebulae with an sdO central star. We present subarcsecond red tunable filter Halpha imaging and intermediate-resolution, long-slit spectroscopy of RWT 152 obtained with OSIRIS/GTC with the goal of analyzing its properties.
arxiv   +1 more source

Iron and copper sulfides in asteroid (162173) Ryugu: Formation conditions and a comparison to the CI and CY chondrites

open access: yesMeteoritics &Planetary Science, Volume 60, Issue 3, Page 506-528, March 2025.
Abstract JAXA's Hayabusa2 sample return mission visited the volatile‐rich carbonaceous (C‐type) asteroid (162173) Ryugu with the aim of ground‐truthing remote observations, returning a pristine sample from a C‐type asteroid, and strengthening links between asteroids and the meteorite collection. Here, we have conducted a systematic study of coarse (>10 
C. S. Harrison   +26 more
wiley   +1 more source

Mid‐infrared detection and characterization of refractory inclusions in CM and CO chondrites: A non‐destructive approach for returned space samples

open access: yesMeteoritics &Planetary Science, Volume 60, Issue 3, Page 544-569, March 2025.
Abstract Refractory inclusions (RIs) in chondrites are widely used as tracers of early solar system formation conditions. In the context of sample‐return missions, a non‐destructive and non‐invasive analytical tool that can rapidly detect and characterize RIs in space samples during their early phase of study is highly needed.
Jean Charlier   +4 more
wiley   +1 more source

VIS‐to‐MIR reflectance and Raman spectroscopy of the CM2 NWA 12184 carbonaceous chondrite

open access: yesMeteoritics &Planetary Science, Volume 60, Issue 3, Page 570-595, March 2025.
Abstract The spectral analysis of CM meteorites can help to constrain the mineralogical composition of their parent body, the C‐type asteroids. The CM2 NWA 12184 was spectrally examined employing seven complementary techniques at different spatial resolutions, including VIS‐to‐MIR reflectance and Raman spectroscopy.
A. Galiano   +15 more
wiley   +1 more source

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