scholarly journals Population III star explosions and Planck 2018 data

2021 ◽  
Vol 103 (12) ◽  
Author(s):  
Katsuya T. Abe ◽  
Hiroyuki Tashiro
Keyword(s):  
Population Iii

scholarly journals Multiple sclerosis patients have reduced resting and increased activated CD4+CD25+FOXP3+T regulatory cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nirupama D. Verma ◽  
Andrew D. Lam ◽  
Christopher Chiu ◽  
Giang T. Tran ◽  
Bruce M. Hall ◽  
...  
Keyword(s):  
T Cells ◽  
T Regulatory Cells ◽  
Mononuclear Cells ◽  
Effector Memory ◽  
Regulatory Cells ◽  
Peripheral Blood Mononuclear ◽  
Healthy Donors ◽  
Treg Population ◽  
Multiple Sclerosis Patients ◽  
Population Iii

AbstractResting and activated subpopulations of CD4+CD25+CD127loT regulatory cells (Treg) and CD4+CD25+CD127+ effector T cells in MS patients and in healthy individuals were compared. Peripheral blood mononuclear cells isolated using Ficoll Hypaque were stained with monoclonal antibodies and analysed by flow cytometer. CD45RA and Foxp3 expression within CD4+ cells and in CD4+CD25+CD127loT cells identified Population I; CD45RA+Foxp3+, Population II; CD45RA−Foxp3hi and Population III; CD45RA−Foxp3+ cells. Effector CD4+CD127+ T cells were subdivided into Population IV; memory /effector CD45RA− CD25−Foxp3− and Population V; effector naïve CD45RA+CD25−Foxp3−CCR7+ and terminally differentiated RA+ (TEMRA) effector memory cells. Chemokine receptor staining identified CXCR3+Th1-like Treg, CCR6+Th17-like Treg and CCR7+ resting Treg. Resting Treg (Population I) were reduced in MS patients, both in untreated and treated MS compared to healthy donors. Activated/memory Treg (Population II) were significantly increased in MS patients compared to healthy donors. Activated effector CD4+ (Population IV) were increased and the naïve/ TEMRA CD4+ (Population V) were decreased in MS compared to HD. Expression of CCR7 was mainly in Population I, whereas expression of CCR6 and CXCR3 was greatest in Populations II and intermediate in Population III. In MS, CCR6+Treg were lower in Population III. This study found MS is associated with significant shifts in CD4+T cells subpopulations. MS patients had lower resting CD4+CD25+CD45RA+CCR7+ Treg than healthy donors while activated CD4+CD25hiCD45RA−Foxp3hiTreg were increased in MS patients even before treatment. Some MS patients had reduced CCR6+Th17-like Treg, which may contribute to the activity of MS.

scholarly journals On Population III Star Formation

1983 ◽  
Vol 104 ◽  
pp. 119-120
Author(s):  
A. Kashlinsky ◽  
M. J. Rees
Keyword(s):  
Background Radiation ◽  
Free Fall ◽  
Compact Objects ◽  
Centrifugal Forces ◽  
Tidal Interactions ◽  
Geometrical Cross Section ◽  
Spin Parameter ◽  
Small Density ◽  
Major Factors ◽  
Population Iii

If primordial fluctuations were isothermal their amplitude at recombination would be non-linear on scales Mo ≃ 106÷9 M⊙. Since the Jeans mass after recombination is MJo ≃ 8 × 105 Ω−1/2 M⊙ the clouds of mass Mo would be able to form the first generation of compact objects, the so-called Population III. These clouds would acquire angular momentum via tidal interactions with their neighbours. The importance of rotation can be conveniently characterised by the spin parameter λ = Vrotation/Vfree-fall and tidal interactions lead to a spin λo = 0.07 ± 0.03. As the cloud collapses λ increases as r−1/2. Any fragment forming in a rotating cloud would have the same spin λ as the whole cloud. It could therefore collapse only by ≃ λo2 in radius before centrifugal forces intervened, thus leaving a large geometrical cross-section for coalescence to be important. At radii r ≲ λo8/5 (Mo/MJo)2/15 ro the coalescence time is shorter than the free-fall time and no fragmentation is possible below this radius. In the primordial clouds two major factors prevent fragmentation at larger radii. First, the background radiation is still ‘hot’ and the trapping of it would prevent fragmentation until the whole cloud has collapsed to a radius 10−2 x−2/3 ro. Here x = 10−2(M/107 M⊙)1/3 is the ionization fraction given by the balance between gravitational contraction and recombination cooling. Furthermore, any small density fluctuation would lead to fragmentation only after the paternal cloud had collapsed by a factor (δ/5)2/3 in radius. For these reasons fragmentation is unlikely until centrifugal forces halt the collapse and a disk forms. The disk will be initially at T ≃ 104K but after a small fraction of H2 forms it will cool to T3 ≃ T/103K ≃ 1 and the final fragments mass could be as low as ≃ 0.2(λo/0.07)4 T32(MJo/Mo)1/3 M⊙.

scholarly journals Gravitational Collapse and Neutrino Emission of Population III Massive Stars

2006 ◽  
Vol 31 ◽  
pp. 205-206
Author(s):  
Ken'ichiro Nakazato ◽  
Kohsuke Sumiyoshi ◽  
Shoichi Yamada
Keyword(s):  
Gravitational Collapse ◽  
Massive Stars ◽  
Neutrino Emission ◽  
Population Iii

Neutrino emission from the collapse of ∼104 M⊙ Population III supermassive stars

2021 ◽  
Vol 508 (1) ◽  
pp. 828-841
Author(s):  
Chris Nagele ◽  
Hideyuki Umeda ◽  
Koh Takahashi ◽  
Takashi Yoshida ◽  
Kohsuke Sumiyoshi
Keyword(s):  
Dark Matter ◽  
Massive Star ◽  
Direct Detection ◽  
Mass Range ◽  
Core Collapse ◽  
Low Density ◽  
Large Radius ◽  
Neutrino Luminosity ◽  
Neutrino Background ◽  
Population Iii

ABSTRACT We calculate the neutrino signal from Population III supermassive star (SMS) collapse using a neutrino transfer code originally developed for core-collapse supernovae and massive star collapse. Using this code, we are able to investigate the SMS mass range thought to undergo neutrino trapping (∼104 M⊙), a mass range which has been neglected by previous works because of the difficulty of neutrino transfer. For models in this mass range, we observe a neutrino sphere with a large radius and low density compared to typical massive star neutrino spheres. We calculate the neutrino light curve emitted from this neutrino sphere. The resulting neutrino luminosity is significantly lower than the results of a previous analytical model. We briefly discuss the possibility of detecting a neutrino burst from an SMS or the neutrino background from many SMSs and conclude that the former is unlikely with current technology, unless the SMS collapse is located as close as 1 Mpc, while the latter is also unlikely even under very generous assumptions. However, the SMS neutrino background is still of interest as it may serve as a source of noise in proposed dark matter direct detection experiments.

Long duration X-ray flash from low mass population III stars

2012 ◽  
Author(s):  
Daisuke Nakauchi ◽  
Yudai Suwa ◽  
Kazumi Kashiyama ◽  
Takashi Nakamura
Keyword(s):  
X Ray ◽  
Long Duration ◽  
Low Mass ◽  
Population Iii Stars ◽  
Population Iii

scholarly journals Effect of Population III multiplicity on dark star formation

2012 ◽  
pp. no-no ◽  
Author(s):  
Athena Stacy ◽  
Andreas H. Pawlik ◽  
Volker Bromm ◽  
Abraham Loeb
Keyword(s):  
Star Formation ◽  
Population Iii

scholarly journals The Persistence of Population III Star Formation

2018 ◽  
Vol 479 (4) ◽  
pp. 4544-4559 ◽  
Author(s):  
Richard H Mebane ◽  
Jordan Mirocha ◽  
Steven R Furlanetto
Keyword(s):  
Star Formation ◽  
Population Iii
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