Laboratory measurement of the OI1173989 Å branching ratio     

M.D. Morrison 《Planetary and Space Science》1985,33(1):135-139

Laboratory measurements of the $\text{OI}\text{1173}\text{989}$ Å (3s' ³D° → 2p⁴¹D, 3s' ³D° → 2p⁴³P) branching ratio have been made with a value of 1.5 × 10^t-4 indicated. This value makes the branching transition at 1173 Å an order of magnitude stronger than the branch at 7990 Å (3s' 3D° → 3p ³P). The 1173 Å branching loss is still too weak a loss process for multiply scattered 989 Å photons to resolve the 989 Å intensity problem in the dayglow.  相似文献   

The nature of Europa's dark non-ice surface material: Spatially-resolved high spectral resolution spectroscopy from the Keck telescope     

John R. Spencer  William M. Grundy  Robert W. Carlson  Gary B. Hansen 《Icarus》2006,182(1):202-210

We present new 1.45-1.75 μm spectra of Europa's dark non-ice material with a spectral resolution (λ/δλ) of 1200, obtained by using adaptive optics on the Keck telescope to spatially separate the spectrum of the non-ice material from that of the surrounding ice-rich regions. Despite the great increase in spectral resolution over the previous best spectra of the non-ice material, taken with Galileo's near-infrared mapping spectrometer (NIMS) with λ/δλ=66, no new fine-scale spectral structure is revealed. The smoothness of the spectra is inconsistent with available laboratory spectra of crystalline hydrated salts at Europa temperatures, but is more consistent with various combinations of non-crystalline hydrated salts and/or hydrated sulfuric acid, as have been matched to the lower-resolution NIMS spectra.  相似文献   

WR 143: a Wolf–Rayet binary     

Watson P. Varricatt  Nagarhalli M. Ashok 《Monthly notices of the Royal Astronomical Society》2006,365(1):127-133

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The Faint Sky Variability Survey – I. Goals and data reduction process     

P. J. Groot  P. M. Vreeswijk  M. E. Huber  M. E. Everett  S. B. Howell  G. Nelemans  J. van Paradijs  E. P. J. van den Heuvel  T. Augusteijn  E. Kuulkers  R. G. M. Rutten  J. Storm 《Monthly notices of the Royal Astronomical Society》2003,339(2):427-434

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The NAIAD experiment for WIMP searches at Boulby mine and recent results     

B. Ahmed  G. J. Alner  H. Araujo  J. C. Barton  A. Bewick  M. J. Carson  D. Davidge  J. V. Dawson  T. Gamble  S. P. Hart  R. Hollingworth  A. S. Howard  W. G. Jones  M. K. Joshi  V. A. Kudryavtsev  T. B. Lawson  V. Lebedenko  M. J. Lehner  J. D. Lewin  P. K. Lightfoot  I. Liubarsky  R. Lüscher  J. E. McMillan  B. Morgan  G. Nicklin  S. M. Paling  R. M. Preece  J. J. Quenby  J. W. Roberts  M. Robinson  N. J. T. Smith  P. F. Smith  N. J. C. Spooner  T. J. Sumner  D. R. Tovey 《Astroparticle Physics》2003,19(6):691-702

The NAIAD experiment (NaI Advanced Detector) for weakly interacting massive particle (WIMP) dark matter searches at Boulby mine (UK) is described. The detector consists of an array of encapsulated and unencapsulated NaI(Tl) crystals with high light yield. Six crystals are collecting data at present. Data accumulated by four of them (10.6 kg × year exposure) have been used to set upper limits on the WIMP–nucleon spin-independent and WIMP–proton spin-dependent cross-sections. Pulse shape analysis has been applied to discriminate between nuclear recoils, as may be caused by WIMP interactions, and electron recoils due to gamma background. Various calibrations of crystals are presented.  相似文献   

Preface     

C. Lobo  M. Serote Roos  A. Biviano 《Astrophysics and Space Science》2003,285(1):1-6

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A statistical evaluation of anomalous redshift claims     

W.M. Napier 《Astrophysics and Space Science》2003,285(2):419-427

Claims that ordinary spiral galaxies and some classes of QSO show periodicity in their redshift distributions are investigated using recent high-precision data and rigorous statistical procedures. The claims are broadly upheld. The periodicites are strong and easily seen by eye in the datasets. Observational, reduction or statistical artefacts do not seem capable of accounting for them. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Probing the core and envelope structure of DBV white dwarfs     

T. S. Metcalfe  M. H. Montgomery  S. D. Kawaler 《Monthly notices of the Royal Astronomical Society》2003,344(4):L88-L92

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Tidal dwarfs in the M81 group: the second generation?     

L. Makarova  E. Grebel  I. Karachentsev  A. Dolphin  V. Karachentseva  M. Sharina  D. Geisler  P. Guhathakurta  P. Hodge  A. Sarajedini  P. Seitzer 《Astrophysics and Space Science》2003,285(1):107-111

We present a quantitative star formation history derivation of the four suspected tidal dwarf galaxies in the M 81 group: Holmberg IX, BK3N,Arp-loop (A0952+69) and Garland using HST/WFPC2 images of these galaxies. We construct a library of synthetic Colour-Magnitude Diagrams(CMDs) based on theoretical isochrones and data-derived determinations of photometric errors. These synthetic CMDs were combined linearly andχ²-compared to observed photometry. All the galaxies show continuous star formation between about 20 and 200 Myr ago with star formation rates between 7.5⋅10^-3 M_⊙/yr and 7.67⋅10^-4 M_⊙/yr. The metallicity of the detected stars is spanning rather a wide range, being lower than solar abundance. We suppose, that all the galaxies were formed out of material from metal-poor outer part of the giant spiral galaxy M81after tidal interaction about 200 Myr ago. However, this suggestion requires significantly more deep color-magnitude diagrams to be sure with the scenario of the galaxy evolution. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Dust-enshrouded super star-clusters     

Marc Sauvage  Stéphanie Plante 《Astrophysics and Space Science》2003,284(2):941-944

With the advent of either sensitive space-born infrared cameras, or their high-resolution ground-based siblings, we are uncovering a new category of star clusters: the dust-enshrouded super-star clusters. These manifest themselves only beyond a few microns, as their shroud of dust is able to block all light emitted by the stars themselves. Here we present our results on the spectacular cluster in SBS 0335-052, a very metal-poor galaxy. We also point to the growing number of galaxy analogs to SBS 0335-052, revealing the possibility that these clusters signal a major mode of star formation in starbursts. We conclude by listing a number of open points these clusters raise, in particular with respect to high-redshift counterparts. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献