scholarly journals Multi-wavelength spectroscopic probes: prospects for primordial non-Gaussianity and relativistic effects

2021 ◽  
Vol 2021 (11) ◽  
pp. 010
Author(s):  
Jan-Albert Viljoen ◽  
José Fonseca ◽  
Roy Maartens
2021 ◽  
Vol 2021 (12) ◽  
pp. 004
Author(s):  
Jan-Albert Viljoen ◽  
José Fonseca ◽  
Roy Maartens

Abstract Next-generation cosmological surveys will observe larger cosmic volumes than ever before, enabling us to access information on the primordial Universe, as well as on relativistic effects. In a companion paper, we applied a Fisher analysis to forecast the expected precision on f NL and the detectability of the lensing magnification and Doppler contributions to the power spectrum. Here we assess the bias on the best-fit values of f NL and other parameters, from neglecting these light-cone effects. We consider forthcoming 21cm intensity mapping surveys (SKAO) and optical galaxy surveys (DESI and Euclid), both individually and combined together. We conclude that lensing magnification at higher redshifts must be included in the modelling of spectroscopic surveys. If lensing is neglected in the analysis, this produces a bias of more than 1σ — not only on f NL, but also on the standard cosmological parameters.


2018 ◽  
Vol 615 ◽  
pp. A163 ◽  
Author(s):  
R. Middei ◽  
S. Bianchi ◽  
M. Cappi ◽  
P.-O. Petrucci ◽  
F. Ursini ◽  
...  

We conducted a multi-wavelength 6-month campaign to observe the Seyfert Galaxy NGC 7469, using the space-based observatories HST, Swift, XMM-Newton and NuSTAR. We report the results of the spectral analysis of the seven simultaneous XMM-Newton and NuSTAR observations. The source shows significant flux variability within each observation, but the average flux is less variable among the different pointings of our campaign. Our spectral analysis reveals a prominent narrow neutral Fe Kα emission line in all the spectra and weaker contributions from Fe Kβ, neutral Ni Kα, and ionized iron. We find no evidence for variability or relativistic effects acting on the emission lines, which indicates that they originate from distant material. In the joint analysis of XMM-Newton and NuSTAR data, a constant photon index is found (Γ = 1.78 ± 0.02) together with a high energy cut-off Ecut = 170−40+60 keV. Adopting a self-consistent Comptonization model, these values correspond to an average coronal electron temperature of kT = 45−12+15 keV and, assuming a spherical geometry, an optical depth τ = 2.6 ± 0.9. The reflection component is consistent with being constant and the reflection fraction is in the range R = 0.3−0.6. A prominent soft excess dominates the spectra below 4 keV. This is best fit with a second Comptonization component, arising from a warm corona with an average kT = 0.67 ± 0.03 keV and a corresponding optical depth τ = 9.2 ± 0.2.


2012 ◽  
Vol 3 (1) ◽  
pp. 1-19
Author(s):  
Giacaglia Giorgio Eugenio Oscare ◽  

1961 ◽  
Vol 75 (9) ◽  
pp. 3-59 ◽  
Author(s):  
N.G. Basov ◽  
Oleg N. Krokhin ◽  
A.N. Oraevskii ◽  
G.M. Strakhovskii ◽  
B.M. Chikhachev

2004 ◽  
Vol 174 (8) ◽  
pp. 861 ◽  
Author(s):  
Andrei I. Musienko ◽  
Leonid I. Manevich
Keyword(s):  

2014 ◽  
Vol 4 (2) ◽  
pp. 555-564
Author(s):  
A.M Aslam

On September 24, 2011 a solar flare of M 7.1 class was released from the Sun. The flare was observed by most of the space and ground based observatories in various wavebands. We have carried out a study of this flare to understand its causes on Sun and impact on earth. The flare was released from NOAA active region AR 11302 at 12:33 UT. Although the region had already produced many M class flares and one X- class flare before this flare, the magnetic configuration was not relaxed and still continued to evolve as seen from HMI observations. From the Solar Dynamics Observatory (SDO) multi-wavelength (131 Ã…, 171 Ã…, 304 Ã… and 1600Ã…) observations we identified that a rapidly rising flux rope triggered the flare although HMI observations revealed that magnetic configuration did not undergo a much pronounced change. The flare was associated with a halo Coronal Mass Ejection (CME) as recorded by LASCO/SOHO Observations. The flare associated CME was effective in causing an intense geomagnetic storm with minimum Dst index -103 nT. A radio burst of type II was also recorded by the WAVES/WIND. In the present study attempt is made to study the nature of coupling between solar transients and geospace.


1997 ◽  
Author(s):  
C. Winstead ◽  
W. Wang ◽  
R. Cook ◽  
G. Miller ◽  
C. Winstead ◽  
...  

2020 ◽  
Author(s):  
Peter Kraus ◽  
Daniel A. Obenchain ◽  
Sven Herbers ◽  
Dennis Wachsmuth ◽  
Irmgard Frank ◽  
...  

<div>The Xe···OCS complex is studied using microwave spectroscopy. Nine isotopologues are measured, and a mass-dependent rm(2) structure is presented. The experiments are supported with a wide array of calculations, including CCSD(T), SAPT, as well as double-hybrid DFT. Trends in the structures of six Rg···OCS complexes (He, Ne, Ar, Kr, Xe, and Hg) are investigated, with particular attention to the deformation of the OCS monomer and relativistic effects. The experimental near-equilibrium structure of Xe···OCS can be predicted to within 11 milliangstrom in the Xe···C distance by correlated wavefunction theory.<br></div>


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