scholarly journals The MUSE Extremely Deep Field: The cosmic web in emission at high redshift

2021 ◽  
Vol 647 ◽  
pp. A107
Author(s):  
R. Bacon ◽  
D. Mary ◽  
T. Garel ◽  
J. Blaizot ◽  
M. Maseda ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Brightness ◽  
Luminosity Function ◽  
Filling Factor ◽  
High Redshift ◽  
Large Population ◽  
Diffuse Emission ◽  
Average Surface ◽  
High Significance ◽  
Circumgalactic Medium

We report the discovery of diffuse extended Lyα emission from redshift 3.1 to 4.5, tracing cosmic web filaments on scales of 2.5−4 cMpc. These structures have been observed in overdensities of Lyα emitters in the MUSE Extremely Deep Field, a 140 h deep MUSE observation located in the Hubble Ultra-Deep Field. Among the 22 overdense regions identified, five are likely to harbor very extended Lyα emission at high significance with an average surface brightness of 5 × 10−20 erg s−1 cm−2 arcsec−2. Remarkably, 70% of the total Lyα luminosity from these filaments comes from beyond the circumgalactic medium of any identified Lyα emitter. Fluorescent Lyα emission powered by the cosmic UV background can only account for less than 34% of this emission at z ≈ 3 and for not more than 10% at higher redshift. We find that the bulk of this diffuse emission can be reproduced by the unresolved Lyα emission of a large population of ultra low-luminosity Lyα emitters (< 1040 erg s−1), provided that the faint end of the Lyα luminosity function is steep (α ⪅ −1.8), it extends down to luminosities lower than 1038 − 1037 erg s−1, and the clustering of these Lyα emitters is significant (filling factor < 1/6). If these Lyα emitters are powered by star formation, then this implies their luminosity function needs to extend down to star formation rates < 10−4 M⊙ yr−1. These observations provide the first detection of the cosmic web in Lyα emission in typical filamentary environments and the first observational clue indicating the existence of a large population of ultra low-luminosity Lyα emitters at high redshift.

scholarly journals The Galaxy UV Luminosity Function Before the Epoch of Reionization

2015 ◽  
Vol 11 (S319) ◽  
pp. 33-33 ◽  
Author(s):  
Charlotte A. Mason ◽  
Michele Trenti ◽  
Tommaso Treu
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Degrees Of Freedom ◽  
Luminosity Function ◽  
High Redshift ◽  
Dark Matter Halos ◽  
Redshift Surveys ◽  
The Galaxy ◽  
Mass Dependent

AbstractWe present a model for the evolution of the galaxy ultraviolet (UV) luminosity function (LF) where star formation is linked to the assembly of dark matter halos under the assumption of a mass dependent, but redshift independent, efficiency. With a calibration at a single redshift, and no further degrees of freedom, our model captures the evolution of the UV LF over all available observations (0≲ z ≲ 10). We make predictions for reionization and future high-redshift surveys with JWST and WFIRST.

scholarly journals A flexible analytic model of cosmic variance in the first billion years

2020 ◽  
Vol 499 (2) ◽  
pp. 2401-2415
Author(s):  
A C Trapp ◽  
Steven R Furlanetto
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Luminosity Function ◽  
Large Scale ◽  
High Redshift ◽  
Mass Function ◽  
Dark Matter Halo ◽  
Analytic Model ◽  
Stellar Feedback ◽  
High Redshift Universe

ABSTRACT Cosmic variance is the intrinsic scatter in the number density of galaxies due to fluctuations in the large-scale dark matter density field. In this work, we present a simple analytic model of cosmic variance in the high-redshift Universe (z ∼ 5–15). We assume that galaxies grow according to the evolution of the halo mass function, which we allow to vary with large-scale environment. Our model produces a reasonable match to the observed ultraviolet (UV) luminosity functions in this era by regulating star formation through stellar feedback and assuming that the UV luminosity function is dominated by recent star formation. We find that cosmic variance in the UV luminosity function is dominated by the variance in the underlying dark matter halo population, and not by differences in halo accretion or the specifics of our stellar feedback model. We also find that cosmic variance dominates over Poisson noise for future high-z surveys except for the brightest sources or at very high redshifts (z ≳ 12). We provide a linear approximation of cosmic variance for a variety of redshifts, magnitudes, and survey areas through the public python package galcv. Finally, we introduce a new method for incorporating priors on cosmic variance into estimates of the galaxy luminosity function and demonstrate that it significantly improves constraints on that important observable.

scholarly journals Galaxy Metabolism

2010 ◽  
Vol 27 (3) ◽  
pp. 233-233
Author(s):  
Andrew Hopkins
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Mass Density ◽  
High Redshift ◽  
Large Population ◽  
Star Formation History ◽  
Global Constraints ◽  
Great Success ◽  
Mass Dependent ◽  
Cosmic History

‘Galaxy Metabolism' was the second in the annual ‘Southern Cross Astrophysics Conference Series’ (http://www.aao.gov.au/AAO/southerncross/), supported by the Anglo-Australian Observatory and the Australia Telescope National Facility. It was held at the Australian National Maritime Museum in Darling Harbour, Sydney, from 22 to 26 June 2009, and was attended by 91 delegates from around the world.Over the past decade, both the star formation history and stellar mass density in galaxies spanning most of cosmic history have been well constrained. This provides the backdrop and framework within which many detailed investigations of galaxy growth are now placed. The mass-dependent and environment-dependent evolution of galaxies over cosmic history is now the focus of several surveys. Many studies are also exploring the role of gas infall and outflow in driving galaxy evolution, and the connection of these processes to massive star formation within galaxies.The aims of ‘Galaxy Metabolism’ were to bring together the global constraints on galaxy evolution, at both low and high redshift, with detailed studies of well-resolved systems, to define a clear picture of our understanding of galaxy metabolism: How do the processes of ingestion (infall), digestion (ISM physics, star formation) and excretion (outflow) govern the global properties of galaxies; how do these change over a galaxy's lifetime; and are the constraints from nearby well resolved studies consistent with those from large population surveys at low and high redshift?The conference was a great success, with an extensive variety of topics covered spanning many aspects of galaxy evolution, and brought together eloquently in a comprehensive conference summary by Warrick Couch. The four papers by De Lucia (2010), Cole (2010), Vlajić (2010) and Stocke et al. (2010) presented in this special collection of PASA are just a sampling of the depth and variety of the resentations given during the conference.

scholarly journals The Warps X-Ray Survey of Galaxies, Groups, and Clusters

1998 ◽  
Vol 179 ◽  
pp. 308-309
Author(s):  
D. Horner ◽  
C.A. Scharf ◽  
L.R. Jones ◽  
H. Ebeling ◽  
E. Perlman ◽  
...  
Keyword(s):  
Hierarchical Models ◽  
Surface Brightness ◽  
Luminosity Function ◽  
High Redshift ◽  
Field Of View ◽  
Archival Data ◽  
Wide Angle ◽  
X Ray ◽  
Fundamental Particles ◽  
Intracluster Gas

We have embarked on a survey of ROSAT PSPC archival data searching for all detected surface brightness enhancements due to sources in the innermost R ≤ 15′ of the PSPC field of view in the energy band 0.5–2.0 keV. This project is part of the Wide Angle ROSAT Pointed Survey (WARPS) and is designed primarily to measure the low luminosity, high redshift, X-ray luminosity function of galaxy clusters and groups. Accurate measurements of the high redshift XLF would allow the form of the XLF evolution to be determined via the position of the Schechter function break. This would help discriminate between luminosity and density evolution, and discriminate between different hierarchical models, e.g., those including a different mix of fundamental particles, a flat power spectrum of the initial fluctuations, and reheating of the intracluster gas at high redshifts.

scholarly journals Galaxy Formation: ISOCAM Counts

1996 ◽  
Vol 168 ◽  
pp. 109-116 ◽  
Author(s):  
C.J. Cesarsky ◽  
D. Elbaz
Keyword(s):  
Galaxy Formation ◽  
Luminosity Function ◽  
High Redshift ◽  
Large Population ◽  
Large Redshift ◽  
Blue Galaxies ◽  
Very High

Detailed observations in the optical do not allow to discriminate between the following scenarii of galaxy formation:- synchronous formation at large redshift (z &gt; 7).- hierarchical merging, down to z ≤ 1, of proto-galactic lumps formed at very high redshift (≈ 10).- galaxy formation at low z (≈ 2-5), but partially obscured by dust.More than 1500 galaxies in a field of 2.6′ × 4.6′ were detected by Tyson (1988) with CCD images in the B band. These deep counts of galaxies revealed the presence of an unexpectedly large population of blue galaxies, corresponding to a number excess of 3 to 5 times more galaxies at B &gt; 23 than one can expect from the local luminosity function. These objects lie apparently at moderate redshift (z = 0.3 for B = 23–24) as shown by spectroscopy of B-selected galaxies (Collesset al.1990).

scholarly journals The Imprints Of Galactic Environment On Cluster Formation and Evolution

2015 ◽  
Vol 12 (S316) ◽  
pp. 17-24
Author(s):  
Angela Adamo
Keyword(s):  
Star Formation ◽  
Formation Process ◽  
Globular Clusters ◽  
High Redshift ◽  
Cluster Formation ◽  
Large Population ◽  
Star Clusters ◽  
Young Star ◽  
Star Formation History ◽  
Formation History

AbstractYoung star clusters (YSCs) appear to be a ubiquitous product of star formation in local galaxies, thus, they can be used to study the star formation process at work in their host galaxies. Moreover, YSCs are intrinsically brighter that single stars, potentially becoming the most important tracers of the recent star formation history in galaxies in the local Universe. In local galaxies, we also witness the presence of a large population of evolved star clusters, commonly called globular clusters (GCs). GCs peak formation history is very close to the redshift (z ~ 2) when the cosmic star formation history reached the maximum. Therefore, GCs are usually associated to extreme star formation episodes in high-redshift galaxies. It is yet not clear whether YSCs and GCs share a similar formation process (same physics under different interstellar medium conditions) and evolution process, and whether the former can be used as progenitor analogs of the latter. In this invited contribution, I review general properties of YSC populations in local galaxies. I will summarise some of the current open questions in the field, with particular emphasis to whether or not galactic environments, where YSCs form, leave imprints on the nested populations. The importance of this rapidly developing field can be crucial in understanding GC formation and possibly the galactic environment condition where this ancient population formed.

scholarly journals The Faint End of the Galaxy Luminosity Function in Rich Clusters

1999 ◽  
Vol 171 ◽  
pp. 60-67
Author(s):  
R.M. Smith ◽  
S. Phillips ◽  
S.P. Driver ◽  
W.J. Couch
Keyword(s):  
Surface Brightness ◽  
Luminosity Function ◽  
Large Population ◽  
Low Surface Brightness ◽  
The Galaxy ◽  
Low Surface Brightness Galaxies ◽  
Galaxy Luminosity Function

AbstractRecent results on the determination of the shape of the faint end of the galaxy luminosity function in rich clusters are discussed. There is increasing evidence that in many cases the faint end of the function is steep, indicating a large population of dwarf, possibly low surface-brightness, galaxies. In addition, the magnitude at which the turn-up appears is approximately constant with richness and distance. However, it is clear that not all clusters show such a feature.

scholarly journals A physical model for [C ii] line emission from galaxies

2019 ◽  
Vol 489 (1) ◽  
pp. 1-12 ◽  
Author(s):  
A Ferrara ◽  
L Vallini ◽  
A Pallottini ◽  
S Gallerani ◽  
S Carniani ◽  
...  
Keyword(s):  
Star Formation ◽  
Surface Brightness ◽  
Star Formation Rate ◽  
High Redshift ◽  
Formation Rate ◽  
Line Emission ◽  
Emission Lines ◽  
Additional Information ◽  
Low Metallicity ◽  
Local Relation

ABSTRACT A tight relation between the [C ii] 158 $\mu$m line luminosity and star formation rate is measured in local galaxies. At high redshift (z > 5), though, a much larger scatter is observed, with a considerable (15–20 per cent) fraction of the outliers being [C ii]-deficient. Moreover, the [C ii] surface brightness ($\Sigma_{\rm [C\, \small {II}]}$) of these sources is systematically lower than expected from the local relation. To clarify the origin of such [C ii]-deficiency, we have developed an analytical model that fits local [C ii] data and has been validated against radiative transfer simulations performed with cloudy. The model predicts an overall increase of $\Sigma_{\rm [C\, \small {II}]}$ with ΣSFR. However, for ΣSFR ${\gtrsim} 1 \, \mathrm{M}_\odot \,{\rm yr}^{-1}\,{\rm kpc}^{-2}$, $\Sigma_{\rm [C\, \small {II}]}$ saturates. We conclude that underluminous [C ii] systems can result from a combination of three factors: (a) large upward deviations from the Kennicutt–Schmidt relation (κs ≫ 1), parametrized by the ‘burstiness’ parameter κs; (b) low metallicity; (c) low gas density, at least for the most extreme sources (e.g. CR7). Observations of [C ii] emission alone cannot break the degeneracy among the above three parameters; this requires additional information coming from other emission lines (e.g. [O iii]88 $\mu$m, C iii]1909 Å, CO lines). Simple formulae are given to interpret available data for low- and high-z galaxies.

scholarly journals The Tully-Fisher Relation as a Function of Redshift: Disentangling Galaxy Evolution and Selection Biases

2006 ◽  
Vol 2 (S235) ◽  
pp. 3-7
Author(s):  
Nicole P. Vogt
Keyword(s):  
Star Formation ◽  
Galaxy Evolution ◽  
Galaxy Formation ◽  
Surface Brightness ◽  
Velocity Structure ◽  
High Redshift ◽  
Selection Effects ◽  
Groups Of Galaxies ◽  
Wide Range ◽  
Fisher Relation

AbstractWe review the status of current observations of the fundamental parameters of intermediate redshift (z ≤ 1.2) disk galaxies. Advances in instrumentation of 8-10m class telescopes have made possible detailed measurements of galaxy luminosity, morphology, kinematics and mass, in both the optical and the infrared passbands. By studying such well known star formation indicators as [OII]3727A (in the optical) and Hα (redshifted to the infrared), the internal velocity structure and star formation rates of galaxies can be traced through this entire redshift regime. The combination of throughput and optimum seeing conditions yields spectra which can be combined with high resolution multiband imaging to explore the evolution of galaxies of various morphologies, and to place constraints on current models of galaxy formation and star formation histories.Out to redshifts of unity, these data form a high redshift Tully-Fisher relation that spans four magnitudes and extends to well below L*, with no obvious change in shape or slope with respect to the local relation. A comparison of disk surface brightness between local and high redshift samples yields an offset in accordance with distance-dependent surface brightness selection effects, as can the apparent change in disk size with redshift for disks of a given mass. These results support low Ω0 models of formation, and provide further evidence for modest increases in luminosity with lookback time for the bulk of the observed field spiral galaxy population.Finally, a comparison of spatially resolved spectra versus integrated emission line widths for distant galaxies suggests that observational constraints bias each type of observational sample toward different sub-groups of galaxies, with different evolutionary histories. Like varying selection effects, this will lead to a wide range of projected evolutionary trends.

scholarly journals Merger rates for early-type galaxies: combining clustering and luminosity function measurements

2012 ◽  
Vol 8 (S295) ◽  
pp. 184-184
Author(s):  
Nelson D. Padilla ◽  
Eric Gawiser ◽  
Daniel Christlein ◽  
Danilo Marchesini
Keyword(s):  
Star Formation ◽  
Luminosity Function ◽  
Rest Frame ◽  
High Redshift ◽  
Stellar Mass ◽  
Mass Selection ◽  
Early Type ◽  
Number Density ◽  
Unit Value

AbstractWe present a study of the evolution of early-type galaxies (ETGs) that combines luminosity function and clustering measurements. This technique shows that ETGs at a given redshift evolve into brighter galaxies in the rest-frame passively evolved optical at lower redshifts. Notice that this indicates that a stellar-mass selection at different redshifts does not necessarily provide samples of galaxies in a progenitor-descendant relationship. The comparison between high redshift ETGs and their likely descendants at z = 0 points to a higher number density for the progenitors by a factor 3 to 11, implying the need for mergers to decrease their number density by today. Because the progenitor-to-descendant ratios of luminosity density are consistent with the unit value, our results show no need for strong star-formation episodes in ETGs since z = 1, which indicates that the needed mergers are dry, i.e. gas free.

Sign in / Sign up

Export Citation Format

Share Document