Variation of the fine-structure constant: very high resolution spectrum of QSO HE 0515-4414
نویسندگان
چکیده
منابع مشابه
Fine - structure diagnostics of neutral carbon toward HE 0515 - 4414
New high-resolution high signal-to-noise spectra of the z = 1.15 damped Lyman α (DLA) system toward the quasi-stellar object HE 0515-4414 reveal absorption lines of the multiplets 2 and 3 in C i. The resonance lines are seen in two components with total column densities of logN = 13.79 ± 0.01 and logN = 13.36 ± 0.01, respectively. The comparision of theoretical calculations of the relative fine...
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We report on detailed Monte Carlo inversion analysis of five Ovi systems from the spectrum of the bright quasar HE 0515–4414 (zem = 1.71). The associated system at zabs = 1.697 with the neutral hydrogen column density N(H i) = 4.4×10 cm shows pronounced absorption from highly ionized transitions of C iii, C iv, Nv, Ovi, Si iv, and probably Svi. We found that only a power law type ionizing spect...
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We consider the problem of the evolution of the fine structure coefficient α under the assumption that the scalar field coupling to the Maxwell term satisfies the condition mt ≫ 1 for coherent dark matter oscillations. In this case we find that the coupling scale f in the leading order coupling −(φ/4f)FμνF μν affects the cosmological evolution of α according to ln(α/α0) ∝ ξ(mPl/f)× ln(tanh(t/2τ...
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Comparison of quasar absorption line spectra with laboratory spectra provides a precise probe for variability of the fine structure constant, α, over cosmological time-scales. We constrain variation in α in 21 Keck/HIRES Si iv absorption systems using the alkali doublet (AD) method in which changes in α are related to changes in the doublet spacing. The precision obtained with the AD method has...
متن کاملDetection of molecular hydrogen at z = 1 . 15 toward HE 0515 – 4414 ⋆
A new molecular hydrogen cloud is found in the sub-damped Lyα absorber [logN(H i) = 19.88± 0.05] at the redshift zabs = 1.15 toward the bright quasar HE 0515–4414 (zem = 1.71). More than 30 absorption features in the Lyman band system of H2 are identified in the UV spectrum of this quasar obtained with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope. The H2-bea...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2006
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20054584