scholarly journals A combined re-analysis of existing blank-field SCUBA surveys: comparative 850-μm source lists, combined number counts, and evidence for strong clustering of the bright submillimetre galaxy population on arcminute scales

2006 ◽  
Vol 370 (3) ◽  
pp. 1057-1105 ◽  
Author(s):  
S. E. Scott ◽  
J. S. Dunlop ◽  
S. Serjeant
Keyword(s):  
Blank Field ◽  
Galaxy Population ◽  
Number Counts

scholarly journals Binary fraction indicators in resolved stellar populations and supernova-type ratios

2020 ◽  
Vol 497 (2) ◽  
pp. 2201-2212 ◽  
Author(s):  
E R Stanway ◽  
J J Eldridge ◽  
A A Chrimes
Keyword(s):  
Massive Star ◽  
Stellar Population ◽  
Stellar Populations ◽  
Initial Mass ◽  
Core Collapse ◽  
Population Synthesis ◽  
Large Samples ◽  
Low Mass ◽  
Galaxy Population ◽  
Number Counts

ABSTRACT The binary fraction of a stellar population can have pronounced effects on its properties, and, in particular, the number counts of different massive star types, and the relative subtype rates of the supernovae (SNe) that end their lives. Here we use binary population synthesis models with a binary fraction that varies with initial mass to test the effects on resolved stellar pops and SNe, and ask whether these can constrain the poorly-known binary fraction in different mass and metallicity regimes. We show that Wolf–Rayet (WR) star subtype ratios are valuable binary diagnostics, but require large samples to distinguish by models. Uncertainties in which stellar models would be spectroscopically classified as WR stars are explored. The ratio of thermonuclear, stripped-envelope, and other core-collapse SNe may prove a more accessible test and upcoming surveys will be sufficient to constrain both the high- and low-mass binary fraction in the z < 1 galaxy population.

scholarly journals Constraints on submicrojansky radio number counts based on evolving VLA-COSMOS luminosity functions

2018 ◽  
Vol 614 ◽  
pp. A47 ◽  
Author(s):  
M. Novak ◽  
V. Smolčić ◽  
E. Schinnerer ◽  
G. Zamorani ◽  
I. Delvecchio ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Emission ◽  
Monte Carlo Algorithm ◽  
Very Large Array ◽  
Star Forming ◽  
Luminosity Functions ◽  
Radio Number ◽  
Galaxy Populations ◽  
Galaxy Population ◽  
Number Counts

We present an investigation of radio luminosity functions (LFs) and number counts based on the Karl G. Jansky Very Large Array-COSMOS 3 GHz Large Project. The radio-selected sample of 7826 galaxies with robust optical/near-infrared counterparts with excellent photometric coverage allows us to construct the total radio LF since z ~ 5.7. Using the Markov chain Monte Carlo algorithm, we fit the redshift dependent pure luminosity evolution model to the data and compare it with previously published VLA-COSMOS LFs obtained on individual populations of radio-selected star-forming galaxies and galaxies hosting active galactic nuclei classified on the basis of presence or absence of a radio excess with respect to the star-formation rates derived from the infrared emission. We find they are in excellent agreement, thus showing the reliability of the radio excess method in selecting these two galaxy populations at radio wavelengths. We study radio number counts down to submicrojansky levels drawn from different models of evolving LFs. We show that our evolving LFs are able to reproduce the observed radio sky brightness, even though we rely on extrapolations toward the faint end. Our results also imply that no new radio-emitting galaxy population is present below 1 μJy. Our work suggests that selecting galaxies with radio flux densities between 0.1 and 10 μJy will yield a star-forming galaxy in 90–95% of the cases with a high percentage of these galaxies existing around a redshift of z ~ 2, thus providing useful constraints for planned surveys with the Square Kilometer Array and its precursors.

scholarly journals ALMA twenty-six arcmin2 survey of GOODS-S at one millimeter (ASAGAO)

2019 ◽  
Vol 15 (S352) ◽  
pp. 239-240
Author(s):  
B. Hatsukade ◽  
K. Kohno ◽  
Y. Yamaguchi ◽  
H. Umehata ◽  
Y. Ao ◽  
...  
Keyword(s):  
Archival Data ◽  
Beam Size ◽  
Density Evolution ◽  
Extragalactic Background Light ◽  
Field Surveys ◽  
Blank Field ◽  
Background Light ◽  
Luminosity Functions ◽  
Number Counts ◽  
Luminosity Evolution

AbstractThe ALMA twenty-six arcmin2 survey of GOODS-S at one millimeter (ASAGAO) is a deep (1σ ∼ 61μJy/beam) and wide area (26 arcmin2) survey on a contiguous field at 1.2 mm. By combining with archival data, we obtained a deeper map in the same region (1σ ∼ 30μJy/beam−1, synthesized beam size 0.59″ × 0.53″), providing the largest sample of sources (25 sources at 5σ, 45 sources at 4.5σ) among ALMA blank-field surveys. The median redshift of the 4.5σ sources is 2.4. The number counts shows that 52% of the extragalactic background light at 1.2 mm is resolved into discrete sources. We create IR luminosity functions (LFs) at z = 1–3, and constrain the faintest luminosity of the LF at 2 < z < 3. The LFs are consistent with previous results based on other ALMA and SCUBA-2 observations, which suggests a positive luminosity evolution and negative density evolution.

The 2–8 [CLC]ke[/CLC]V X-Ray Number Counts Determined from [ITAL]Chandra[/ITAL] Blank Field Observations

2002 ◽  
Vol 566 (1) ◽  
pp. L5-L8 ◽  
Author(s):  
L. L. Cowie ◽  
G. P. Garmire ◽  
M. W. Bautz ◽  
A. J. Barger ◽  
W. N. Brandt ◽  
...  
Keyword(s):  
Field Observations ◽  
Blank Field ◽  
X Ray ◽  
Number Counts

scholarly journals The Evolution of Field Galaxies

1996 ◽  
Vol 171 ◽  
pp. 209-216 ◽  
Author(s):  
S.J. Lilly ◽  
O. Le Fevre ◽  
F. Hammer ◽  
D. Crampton ◽  
D.J. Schade ◽  
...  
Keyword(s):  
Luminosity Function ◽  
Statistical Weight ◽  
List Type ◽  
Type Number ◽  
Local Populations ◽  
Redshift Surveys ◽  
Different Types ◽  
The Galaxy ◽  
Galaxy Population ◽  
Number Counts

During the late 1980's, successively deeper redshift surveys carried out with multi-object spectrographs on 4-m class telescopes produced growing evidence for evolution in the galaxy population. While some evolution had been expected from analysis of the galaxy number counts, the surprising indication from the first deep redshift surveys was that this appeared to involve moderate luminosity galaxies lying at moderate redshifts (Broadhurst et al. 1988, Colless et al. 1990, Cowie et al. 1991). However, while the results were suggestive, these early surveys suffered a number of significant problems that hampered their interpretation: (a)the samples were small, especially at the faintest levels, so the statistical weight was limited and analysis was based on crude parameterizations of the data such as the median redshift of samples;(b)the typical redshifts were small (z << 0.5), so that evolutionary effects could only be seen against “local” populations whose selection was often quite different - indeed the local luminosity function of galaxies is still poorly defined (Loveday et al. 1992, Marzke et al. 1994);(c)the samples were selected in the observed B-band, so that comparison with local samples was based on the poorly constrained ultraviolet properties and relative numbers of galaxies of different types.

scholarly journals Radio continuum size evolution of star-forming galaxies over 0.35 < z < 2.25

2019 ◽  
Vol 625 ◽  
pp. A114 ◽  
Author(s):  
E. F. Jiménez-Andrade ◽  
B. Magnelli ◽  
A. Karim ◽  
G. Zamorani ◽  
M. Bondi ◽  
...  
Keyword(s):  
Star Formation ◽  
Formation Rate ◽  
Gaussian Model ◽  
Cosmic Time ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Selection Function ◽  
Star Forming ◽  
Size Evolution ◽  
Galaxy Population

To better constrain the physical mechanisms driving star formation, we present the first systematic study of the radio continuum size evolution of star-forming galaxies (SFGs) over the redshift range 0.35 <  z <  2.25. We use the VLA COSMOS 3 GHz map (noise rms = 2.3 μJy beam−1, θbeam = 0.75 arcsec) to construct a mass-complete sample of 3184 radio-selected SFGs that reside on and above the main sequence (MS) of SFGs. We constrain the overall extent of star formation activity in galaxies by applying a 2D Gaussian model to their radio continuum emission. Extensive Monte Carlo simulations are used to validate the robustness of our measurements and characterize the selection function. We find no clear dependence between the radio size and stellar mass, M⋆, of SFGs with 10.5 ≲ log(M⋆/M⊙) ≲ 11.5. Our analysis suggests that MS galaxies are preferentially extended, while SFGs above the MS are always compact. The median effective radius of SFGs on (above) the MS of Reff = 1.5 ± 0.2 (1.0 ± 0.2) kpc remains nearly constant with cosmic time; a parametrization of the form Reff ∝ (1 + z)α yields a shallow slope of only α = −0.26 ± 0.08 (0.12 ± 0.14) for SFGs on (above) the MS. The size of the stellar component of galaxies is larger than the extent of the radio continuum emission by a factor ∼2 (1.3) at z = 0.5 (2), indicating star formation is enhanced at small radii. The galactic-averaged star formation rate surface density (ΣSFR) scales with the distance to the MS, except for a fraction of MS galaxies (≲10%) that harbor starburst-like ΣSFR. These “hidden” starbursts might have experienced a compaction phase due to disk instability and/or a merger-driven burst of star formation, which may or may not significantly offset a galaxy from the MS. We thus propose to use ΣSFR and distance to the MS in conjunction to better identify the galaxy population undergoing a starbursting phase.

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