scholarly journals Observing the tail of reionization: neutral islands in the z = 5.5 Lyman-α forest

2020 ◽  
Vol 494 (3) ◽  
pp. 3080-3094 ◽  
Author(s):  
Fahad Nasir ◽  
Anson D’Aloisio
Keyword(s):  
Free Path ◽  
Thermal History ◽  
Neutral Hydrogen ◽  
Mean Free Path ◽  
Common Assumption ◽  
Large Fluctuations ◽  
Independent Observations ◽  
The Common ◽  
Dark Pixel ◽  
Almost All

ABSTRACT Previous studies have noted difficulties in modelling the highest opacities of the z > 5.5 Ly α forest, epitomized by the extreme Lyα trough observed towards quasar ULAS J0148 + 0600. One possibility is that the most opaque regions at these redshifts contain significant amounts of neutral hydrogen. This explanation, which abandons the common assumption that reionization ended before z = 6, also reconciles evidence from independent observations of a significantly neutral Universe at z = 7.5. Here, we explore a model in which the neutral fraction is still ${\approx }10{{\ \rm per\ cent}}$ at z = 5.5. We confirm that this model can account for the observed scatter in Ly α forest opacities, as well as the observed Ly β transmission in the J0148 trough. We contrast the model with a competing ‘earlier’ reionization scenario characterized by a short mean free path and large fluctuations in the post-reionization ionizing background. We consider Ly α and Ly β effective optical depths, their correlations, trough size distributions, dark pixel fractions, the IGM thermal history, and spatial distributions of Lyman-α emitters around forest sightlines. We find that the models are broadly similar in almost all of these statistics, suggesting that it may be difficult to distinguish between them definitively. We argue that improved constraints on the mean free path and the thermal history at z > 5 could go a long way towards diagnosing the origin of the z > 5.5 opacity fluctuations.

Inelastic mean free path and phase-shift determinations in NiO, using EXELFS

1993 ◽  
Vol 3 (7) ◽  
pp. 1649-1659
Author(s):  
Mohammad A. Tafreshi ◽  
Stefan Csillag ◽  
Zou Wei Yuan ◽  
Christian Bohm ◽  
Elisabeth Lefèvre ◽  
...  
Keyword(s):  
Phase Shift ◽  
Free Path ◽  
Mean Free Path ◽  
Inelastic Mean Free Path

Fibrinolytic Activity of the Arterial Wall

1969 ◽  
Vol 21 (01) ◽  
pp. 001-011 ◽  
Author(s):  
K Onoyama ◽  
K Tanaka
Keyword(s):  
Carotid Artery ◽  
Fibrinolytic Activity ◽  
Arterial Wall ◽  
Aortic Wall ◽  
Internal Carotid ◽  
Atheromatous Plaque ◽  
Human Fibrinogen ◽  
The Media ◽  
The Common ◽  
Almost All

SummaryThe tissue fibrinolysis was studied in 550 specimens of 7 kinds of arteries from 80 fresh cadavers, using Astrup’s biochemical method and Todd’s histochemical method with human fibrinogen.In the microscopically normal aortic wall, almost all specimens had the fibrinolytic activity which was the strongest in the adventitia and the weakest in the media.The fibrinolytic activity seemed to be localized in the endothelium.The stronger activity lay in the adventitia of the aorta and the pulmonary artery and all layers of the cerebral artery.The activity of the intima and media of the macroscopically normal areas seemed to be stronger in the internal carotid artery than in the common carotid artery.Mean fibrinolytic activity of the macroscopically normal areas seemed to decrease with age in the intima and the media of the thoracic aorta and seemed to be low in the cases with a high atherosclerotic index.The fibrinolytic activities of all three layers of the fibrous thickened aorta seemed to decrease, and those of the media and the adventitia of the atheromatous plaque to increase.The fibrinolytic activity of the arterial wall might play some role in the progress of atherosclerosis.

Student Perceptions of Community: A Different Perspective

NASPA Journal ◽  
1998 ◽  
Vol 35 (4) ◽  
Author(s):  
Jackie Clark ◽  
Joan Hirt
Keyword(s):  
Student Perceptions ◽  
Large Scale ◽  
Research University ◽  
Small Scale ◽  
Social Environments ◽  
Common Assumption ◽  
Small Communities ◽  
Public Research University ◽  
The Common ◽  
Using Data

The creation of small communities has been proposed as a way of enhancing the educational experience of students at large institutions. Using data from a survey of students living in large and small residences at a public research university, this study does not support the common assumption that small-scale social environments are more conducive to positive community life than large-scale social environments.

The measurement of mean free path λs using a slowing down time lead spectrometer in the 1–10 eV energy region

1968 ◽  
Vol 22 (4) ◽  
pp. 261-262
Author(s):  
M.P. Navalkar ◽  
K. Chandramoleshwar ◽  
D.V.S. Ramkrishna
Keyword(s):  
Free Path ◽  
Energy Region ◽  
Mean Free Path ◽  
Slowing Down ◽  
Time Lead

scholarly journals Śaivism after the Śaiva Age: Continuities in the Scriptural Corpus of the Vīramāheśvaras

Religions ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 222
Author(s):  
Elaine M. Fisher
Keyword(s):  
Thirteenth Century ◽  
Common Assumption ◽  
Academic Practice ◽  
The Common ◽  
Popular Work ◽  
First Time

This article makes the case that Vīraśaivism emerged in direct textual continuity with the tantric traditions of the Śaiva Age. In academic practice up through the present day, the study of Śaivism, through Sanskrit sources, and bhakti Hinduism, through the vernacular, are generally treated as distinct disciplines and objects of study. As a result, Vīraśaivism has yet to be systematically approached through a philological analysis of its precursors from earlier Śaiva traditions. With this aim in mind, I begin by documenting for the first time that a thirteenth-century Sanskrit work of what I have called the Vīramāheśvara textual corpus, the Somanāthabhāṣya or Vīramāheśvarācārasāroddhārabhāṣya, was most likely authored by Pālkurikĕ Somanātha, best known for his vernacular Telugu Vīraśaiva literature. Second, I outline the indebtedness of the early Sanskrit and Telugu Vīramāheśvara corpus to a popular work of early lay Śaivism, the Śivadharmaśāstra, with particular attention to the concepts of the jaṅgama and the iṣṭaliṅga. That the Vīramāheśvaras borrowed many of their formative concepts and practices directly from the Śivadharmaśāstra and other works of the Śaiva Age, I argue, belies the common assumption that Vīraśaivism originated as a social and religious revolution.

scholarly journals Controllable transport mean free path of light in xerogel matrixes embedded with polystyrene spheres

2009 ◽  
Vol 17 (9) ◽  
pp. 6975 ◽  
Author(s):  
Boris P. Bret ◽  
Nuno J. Couto ◽  
Mariana Amaro ◽  
Eduardo J. Nunes-Pereira ◽  
Michael Belsley
Keyword(s):  
Free Path ◽  
Mean Free Path ◽  
Polystyrene Spheres
Sign in / Sign up

Export Citation Format

Share Document