Beyond FIRST and Planck

2005 ◽  
Vol 201 ◽  
pp. 395-399
Author(s):  
Matt. Griffin
Keyword(s):  
Background Radiation ◽  
High Redshift ◽  
Wavelength Region ◽  
Cosmic Background Radiation ◽  
Detailed Examination ◽  
Energy Scale ◽  
High Redshift Galaxies ◽  
Cosmic Background ◽  
Imaging And Spectroscopy ◽  
Redshift Galaxies

Prospects for future satellite missions, operating in the FIR-mm wavelength region, to study the polarisation of the cosmic background radiation (CBR) and to carry out imaging and spectroscopy of high-redshift galaxies, are discussed. Full characterisation of the CBR polarisation offers the possibility of determining the energy scale of inflation and constraining the form of the inflaton potential. Current technology in FIR imaging and spectroscopy falls well short of matching capabilities in the optical/UV and the mm regions. Filling this gap is important to allow detailed examination of the physics and evolution of high-redshift galaxies, and will be possible with future FIR observatories which are now being studied.

scholarly journals Intensity Fluctuations of the Cosmic Background Radiation Due to Polarization Effects

1990 ◽  
Vol 139 ◽  
pp. 402-403
Author(s):  
Bronislaw Rudak
Keyword(s):  
Background Radiation ◽  
High Redshift ◽  
Cosmic Background Radiation ◽  
Blackbody Radiation ◽  
Polarization Effects ◽  
Cosmic Background ◽  
Intensity Fluctuations

The Nagoya-Berkeley experiment has revealed a substantial excess over the blackbody radiation in the submillimetre part of wavelengths. Its origin is unknown. The concept of high-redshift cosmological dust (e.g., Hayakawa et al., 1987), though not without problems, remains one of the simplest explanations. It is clear that other types of observations will be necessary to identify the source of the excess. Needless to say, searches for cosmic background radiation (CBR) intensity fluctuations on fine angular scales in the submillimetre region are especially desired.

scholarly journals Diffraction Limited Imaging of High Redshift Galaxies with Adaptive Optics

2001 ◽  
Vol 205 ◽  
pp. 455-456 ◽  
Author(s):  
R.I. Davies ◽  
M. Lehnert ◽  
A.J. Baker ◽  
S. Rabien
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
High Redshift ◽  
Diffraction Limit ◽  
High Redshift Galaxies ◽  
Distant Galaxies ◽  
Imaging And Spectroscopy ◽  
Intermediate Redshift ◽  
Initial Results ◽  
Redshift Galaxies

The major cornerstone of future ground-based astronomy is imaging and spectroscopy at the diffraction limit using adaptive optics. To exploit the potential of current AO systems, we have begun a survey around bright stars to study intermediate redshift galaxies at high resolution. Using ALFA to reach the diffraction limit of the 3.5-m telescope at Calar Alto allows us to study the structure of distant galaxies in the near-infrared at scales of 100-150 pc for z=0.05 and at scales 1.0-1.5 kpc at z=1. In this contribution we present the initial results of this project, which hint at the exciting prospects possible with the resolution and sensitivity available using an AO camera on the 8-m class VLT.

scholarly journals Exponential Growth of Distance between Nearby Rays Due to Multiple Gravitational Lensing

1996 ◽  
Vol 173 ◽  
pp. 93-94
Author(s):  
T. Fukushige ◽  
J. Makino
Keyword(s):  
Ray Tracing ◽  
Gravitational Lensing ◽  
Exponential Growth ◽  
Background Radiation ◽  
High Redshift ◽  
Cosmic Background Radiation ◽  
System Size ◽  
Cosmic Background

We have investigated multiple gravitational lensing by numerical “ray tracing” simulations. We have found that the distance between rays grows exponentially, on average, until it reaches the projected mean separation of lensing objects (∼ RV–1/2, where R is the system size and N is the number of scattering object). This nature may affect observations of high redshift objects or the anisotropy of the cosmic background radiation.

scholarly journals TRACING THE EVOLUTION OF HIGH-REDSHIFT GALAXIES USING STELLAR ABUNDANCES

2016 ◽  
Vol 820 (1) ◽  
pp. 71 ◽  
Author(s):  
Brian D. Crosby ◽  
Brian W. O’Shea ◽  
Timothy C. Beers ◽  
Jason Tumlinson
Keyword(s):  
High Redshift ◽  
Stellar Abundances ◽  
High Redshift Galaxies ◽  
Redshift Galaxies

scholarly journals Self-consistent proto-globular cluster formation in cosmological simulations of high-redshift galaxies

2020 ◽  
Vol 493 (3) ◽  
pp. 4315-4332 ◽  
Author(s):  
Xiangcheng Ma ◽  
Michael Y Grudić ◽  
Eliot Quataert ◽  
Philip F Hopkins ◽  
Claude-André Faucher-Giguère ◽  
...  
Keyword(s):  
High Pressure ◽  
Star Formation ◽  
High Redshift ◽  
Cluster Formation ◽  
Mass Function ◽  
Cosmological Simulations ◽  
High Redshift Galaxies ◽  
Cluster Mass ◽  
Formation Efficiency ◽  
Redshift Galaxies

ABSTRACT We report the formation of bound star clusters in a sample of high-resolution cosmological zoom-in simulations of z ≥ 5 galaxies from the Feedback In Realistic Environments project. We find that bound clusters preferentially form in high-pressure clouds with gas surface densities over $10^4\, \mathrm{ M}_{\odot }\, {\rm pc}^{-2}$, where the cloud-scale star formation efficiency is near unity and young stars born in these regions are gravitationally bound at birth. These high-pressure clouds are compressed by feedback-driven winds and/or collisions of smaller clouds/gas streams in highly gas-rich, turbulent environments. The newly formed clusters follow a power-law mass function of dN/dM ∼ M−2. The cluster formation efficiency is similar across galaxies with stellar masses of ∼107–$10^{10}\, \mathrm{ M}_{\odot }$ at z ≥ 5. The age spread of cluster stars is typically a few Myr and increases with cluster mass. The metallicity dispersion of cluster members is ∼0.08 dex in $\rm [Z/H]$ and does not depend on cluster mass significantly. Our findings support the scenario that present-day old globular clusters (GCs) were formed during relatively normal star formation in high-redshift galaxies. Simulations with a stricter/looser star formation model form a factor of a few more/fewer bound clusters per stellar mass formed, while the shape of the mass function is unchanged. Simulations with a lower local star formation efficiency form more stars in bound clusters. The simulated clusters are larger than observed GCs due to finite resolution. Our simulations are among the first cosmological simulations that form bound clusters self-consistently in a wide range of high-redshift galaxies.

scholarly journals Introductory Remarks

2001 ◽  
Vol 204 ◽  
pp. 5-15
Author(s):  
P. J. E. Peebles
Keyword(s):  
Star Formation ◽  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Morphological Type ◽  
Star Formation History ◽  
Cosmic Background ◽  
Formation History ◽  
Infrared Background

I review the assumptions and observations that motivate the concept of the extragalactic cosmic background radiation, and the issues of energy accounts and star formation history as a function of galaxy morphological type that figure in the interpretation of the measurements of the extragalactic infrared background.

scholarly journals New methods for identifying Lyman continuum leakers and reionization-epoch analogues

2020 ◽  
Vol 498 (1) ◽  
pp. 164-180 ◽  
Author(s):  
Harley Katz ◽  
Dominika Ďurovčíková ◽  
Taysun Kimm ◽  
Joki Rosdahl ◽  
Jeremy Blaizot ◽  
...  
Keyword(s):  
Emission Line ◽  
Galaxy Formation ◽  
Dwarf Galaxy ◽  
High Redshift ◽  
Indirect Methods ◽  
High Redshift Galaxies ◽  
Lyman Continuum ◽  
The Universe ◽  
Ionization Parameter ◽  
Redshift Galaxies

ABSTRACT Identifying low-redshift galaxies that emit Lyman continuum radiation (LyC leakers) is one of the primary, indirect methods of studying galaxy formation in the epoch of reionization. However, not only has it proved challenging to identify such systems, it also remains uncertain whether the low-redshift LyC leakers are truly ‘analogues’ of the sources that reionized the Universe. Here, we use high-resolution cosmological radiation hydrodynamics simulations to examine whether simulated galaxies in the epoch of reionization share similar emission line properties to observed LyC leakers at z ∼ 3 and z ∼ 0. We find that the simulated galaxies with high LyC escape fractions (fesc) often exhibit high O32 and populate the same regions of the R23–O32 plane as z ∼ 3 LyC leakers. However, we show that viewing angle, metallicity, and ionization parameter can all impact where a galaxy resides on the O32–fesc plane. Based on emission line diagnostics and how they correlate with fesc, lower metallicity LyC leakers at z ∼ 3 appear to be good analogues of reionization-era galaxies. In contrast, local [S ii]-deficient galaxies do not overlap with the simulated high-redshift LyC leakers on the S ii Baldwin–Phillips–Terlevich (BPT) diagram; however, this diagnostic may still be useful for identifying leakers. We use our simulated galaxies to develop multiple new diagnostics to identify LyC leakers using infrared and nebular emission lines. We show that our model using only [C ii]158 μm and [O iii]88 μm can identify potential leakers from non-leakers from the local Dwarf Galaxy Survey. Finally, we apply this diagnostic to known high-redshift galaxies and find that MACS 1149_JD1 at z = 9.1 is the most likely galaxy to be actively contributing to the reionization of the Universe.

South Pole studies of the anisotropy of the cosmic background radiation at one degree

1990 ◽  
Author(s):  
Peter R. Meinhold ◽  
Philip M. Lubin ◽  
Alfredo O. Chingcuanco ◽  
Jeff A. Schuster ◽  
Michael Seiffert
Keyword(s):  
Background Radiation ◽  
Cosmic Background Radiation ◽  
South Pole ◽  
Cosmic Background
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