scholarly journals Evolution of Galaxy Luminosity in the CDM Model

1996 ◽  
Vol 168 ◽  
pp. 503-504
Author(s):  
Mirta Mosconi ◽  
Patricia Tissera ◽  
Diego Garcia Lambas

we analyze the evolution of the luminosity function of galaxies using the CDM model in numerical simulations. There is an observational excess in the number counts of galaxies per square degree in the blur band Nb(i.e. APM, Maddoxet al.1990). Several authors have tried to reproduce it trying to fit the observations. Our model assumes an instantaneous star formation rate (SFR) proportional to a power of the local density. A ‘single star burst’ is produced each time step and we follow the evolution of the luminosity and colour of each ‘stellar group’. The galaxies are identified with a density criterium. We compute U,V,B,K colours and Nband our results agree quite well with observations.

2019 ◽  
Vol 15 (S352) ◽  
pp. 70-70
Author(s):  
Rohan Potham Naidu

AbstractWe present an empirical model built on a high-resolution N-body dark matter simulation. We assume a redshift-independent star-formation efficiency for each halo to convert the accretion rate into a star-formation rate. Our model is calibrated using the z = 4 UV luminosity function (UVLF) and successfully predicts the observed UVLF at z = 5 – 10. We present predictions at z = 5 – 10 for UV luminosity and stellar mass functions, JWST number counts, the stellar-to-halo mass relation and star-formation histories. We combine this model with bleeding-edge reionization constraints (from z > 7 quasars, z ∼ 7 Ly α line-profiles, the updated Planck τ) to find new perspectives on the Epoch of Reionization (EoR). We find MUV < − 13.5 galaxies need an average fesc = 0.22 ± 0.05 to drive reionization and a highly compressed timeline: the IGM neutral fraction is [0.9, 0.5, 0.1] at z = [8.4 ± 0.2, 7.0 ± 0.2, 6.3 ± 0.2]. Inspired by the newly assembled sample of Lyman Continuum leakers that unanimously displays higher-than-average star-formation surface density (sigma), we fit a model tying fesc to sigma. Since sigma grows by > 2.5 dex over z = 0 – 8, our model explains the humble values of fesc at low-z. We find, strikingly, that < 5% of galaxies with MUV < − 18 account for > 80% of the reionization budget. We predict leakers like COLA1 (z = 6.6, MUV = − 21.5) become common towards the EoR and that the protagonists of reionization are not hiding across the faint-end of the luminosity function but are already known to us.


2020 ◽  
Vol 899 (1) ◽  
pp. 5
Author(s):  
Kei Ito ◽  
Nobunari Kashikawa ◽  
Jun Toshikawa ◽  
Roderik Overzier ◽  
Mariko Kubo ◽  
...  

2019 ◽  
Vol 488 (2) ◽  
pp. 2202-2221 ◽  
Author(s):  
Jason Jaacks ◽  
Steven L Finkelstein ◽  
Volker Bromm

ABSTRACT We utilize gizmo, coupled with newly developed sub-grid models for Population III (Pop III) and Population II (Pop II), to study the legacy of star formation in the pre-reionization Universe. We find that the Pop II star formation rate density (SFRD), produced in our simulation (${\sim } 10^{-2}\ \mathrm{M}_\odot \, {\rm yr^{-1}\, Mpc^{-3}}$ at z ≃ 10), matches the total SFRD inferred from observations within a factor of &lt;2 at 7 ≲ z ≲ 10. The Pop III SFRD, however, reaches a plateau at ${\sim }10^{-3}\ \mathrm{M}_\odot \, {\rm yr^{-1}\, Mpc^{-3}}$ by z ≈ 10, remaining largely unaffected by the presence of Pop II feedback. At z  = 7.5, ${\sim } 20{{\ \rm per\ cent}}$ of Pop III star formation occurs in isolated haloes that have never experienced any Pop II star formation (i.e. primordial haloes). We predict that Pop III-only galaxies exist at magnitudes MUV ≳ −11, beyond the limits for direct detection with the James Webb Space Telescope. We assess that our stellar mass function (SMF) and UV luminosity function (UVLF) agree well with the observed low mass/faint-end behaviour at z = 8 and 10. However, beyond the current limiting magnitudes, we find that both our SMF and UVLF demonstrate a deviation/turnover from the expected power-law slope (MUV,turn = −13.4 ± 1.1 at z  = 10). This could impact observational estimates of the true SFRD by a factor of 2(10) when integrating to MUV = −12 (−8) at z ∼ 10, depending on integration limits. Our turnover correlates well with the transition from dark matter haloes dominated by molecular cooling to those dominated by atomic cooling, for a mass Mhalo ≈ 108 M⊙ at z ≃ 10.


Author(s):  
Lucia Marchetti ◽  
Mattia Vaccari ◽  
Alberto Franceschini

AbstractWe exploit the Herschel Extragalactic Multi-Tiered Survey (HerMES) dataset along with ancillary multi-wavelength photometry and spectroscopy from the Spitzer Data Fusion to provide the most accurate determination to date of the local (0.02<z<0.5) Far-Infrared Luminosity and Star Formation Rate Function. We present and compare our results with model predictions as well as other multi-wavelength estimates of the local star formation rate density.


Author(s):  
James E. Upjohn ◽  
Michael J. I. Brown ◽  
Andrew M. Hopkins ◽  
Nicolas J. Bonne

AbstractWe measure the cosmic star formation history out to z = 1.3 using a sample of 918 radio-selected star-forming galaxies within the 2-deg2 COSMOS field. To increase our sample size, we combine 1.4-GHz flux densities from the VLA-COSMOS catalogue with flux densities measured from the VLA-COSMOS radio continuum image at the positions of I &lt; 26.5 galaxies, enabling us to detect 1.4-GHz sources as faint as 40 μJy. We find that radio measurements of the cosmic star formation history are highly dependent on sample completeness and models used to extrapolate the faint end of the radio luminosity function. For our preferred model of the luminosity function, we find the star formation rate density increases from 0.017 M⊙ yr−1 Mpc−3 at z ∼ 0.225 to 0.092 M⊙ yr−1 Mpc−3 at z ∼ 1.1, which agrees to within 40% of recent UV, IR and 3-GHz measurements of the cosmic star formation history.


2020 ◽  
Vol 494 (4) ◽  
pp. 5985-5991
Author(s):  
T Cheng ◽  
D L Clements ◽  
J Greenslade ◽  
J Cairns ◽  
P Andreani ◽  
...  

ABSTRACT We measure the 850-μm source densities of 46 candidate protoclusters selected from the Planck high-z catalogue (PHz) and the Planck Catalogue of Compact Sources (PCCS) that were followed up with Herschel-SPIRE and SCUBA-2. This paper aims to search for overdensities of 850-μm sources in order to select the fields that are most likely to be genuine protoclusters. Of the 46 candidate protoclusters, 25 have significant overdensities (&gt;5 times the field counts), 11 have intermediate overdensities (3–5 times the field counts), and 10 have no overdensity (&lt;3 times the field counts) of 850-μm sources. We find that the enhanced number densities are unlikely to be the result of sample variance. Compared with the number counts of another sample selected from Planck’s compact source catalogues, this [PHz + PCCS]-selected sample has a higher fraction of candidate protoclusters with significant overdensities, though both samples show overdensities of 850-μm sources above intermediate level. Based on the estimated star formation rate densities (SFRDs), we suggest that both samples can efficiently select protoclusters with starbursting galaxies near the redshift at which the global field SFRD peaks (2 &lt; z &lt; 3). Based on the confirmation of overdensities found here, future follow-up observations on other PHz targets may greatly increase the number of genuine dusty star-forming galaxy-rich clusters/protoclusters.


2013 ◽  
Vol 780 (2) ◽  
pp. 143 ◽  
Author(s):  
Anahita Alavi ◽  
Brian Siana ◽  
Johan Richard ◽  
Daniel P. Stark ◽  
Claudia Scarlata ◽  
...  

2007 ◽  
Vol 654 (1) ◽  
pp. 172-185 ◽  
Author(s):  
Tomas Dahlen ◽  
Bahram Mobasher ◽  
Mark Dickinson ◽  
Henry C. Ferguson ◽  
Mauro Giavalisco ◽  
...  

2019 ◽  
Vol 631 ◽  
pp. A10 ◽  
Author(s):  
Marina Ramón-Pérez ◽  
Ángel Bongiovanni ◽  
Ana María Pérez García ◽  
Jordi Cepa ◽  
Maritza A. Lara-López ◽  
...  

Aims. We take advantage of the capability of the OTELO survey to obtain the Hα luminosity function (LF) at z ∼ 0.40. Because of the deepest coverage of OTELO, we are able to determine the faint end of the LF, and thus better constrain the star formation rate and the number of galaxies at low luminosities. The AGN contribution to this LF is estimated as well. Methods. We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, which is unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification of emission lines and the discrimination of different types of objects. Results. The Hα luminosity function at z ∼ 0.40 is obtained, which extends the current faint end by almost 1 dex, reaching minimal luminosities of log10Llim = 38.5 erg s−1 (or ∼0.002 M⊙ yr−1). The AGN contribution to the total Hα luminosity is estimated. We find that no AGN should be expected below a luminosity of log10L = 38.6 erg s−1. From the sample of non-AGN (presumably, pure SFG) at z ∼ 0.40 we estimated a star formation rate density of ρSFR = 0.012 ± 0.005 M⊙ yr−1 Mpc−3.


2019 ◽  
Vol 15 (S352) ◽  
pp. 349-349
Author(s):  
Caitlin Casey

AbstractThough half of cosmic starlight is absorbed by dust and reradiated at long wavelengths (3μ m – 3 mm), constraints on the infrared through millimeter galaxy luminosity function (the ‘IRLF’) are poor in comparison to the rest-frame ultraviolet and optical galaxy luminosity function, particularly at z ⩾ 2.5. Here we present a backward evolution model for interpreting number counts, redshift distributions, and cross-band flux density correlations in the infrared and submillimeter sky, from 70μm – 2 mm, using a model for the IRLF out to the epoch of reionization. Mock submillimeter maps are generated by injecting sources according to the prescribed IRLF and flux densities drawn from model spectral energy distributions that mirror the distribution of SEDs observed in 0 < z 0 < 5 dusty star-forming galaxies (DSFGs). We explore two extreme hypothetical case-studies: a dust-poor early Universe model, where DSFGs contribute negligibly (< 10%) to the integrated star-formation rate density at z > 4, and an alternate dust-rich early Universe model, where DSFGs dominate > 90% of z > 4 star-formation. We find that current submm/mm datasets do not clearly rule out either of these extreme models. We suggest that future surveys at 2 mm – both from ALMA and single-dish facilities – will be crucial to measuring the IRLF beyond z > 4.


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