scholarly journals Predictions for the FAST telescope’s CRAFTS extragalactic H i survey

2020 ◽  
Vol 500 (2) ◽  
pp. 1741-1754
Author(s):  
Kai Zhang ◽  
Jingwen Wu ◽  
Di Li ◽  
Chao-Wei Tsai ◽  
Lister Staveley-Smith ◽  
...  
Keyword(s):  
Mass Velocity ◽  
Mass Function ◽  
Radio Frequency Interference ◽  
Local Universe ◽  
Galaxy Interactions ◽  
Technical Parameters ◽  
Simulation Based ◽  
Width Function ◽  
The Galaxy ◽  
Knee Mass

ABSTRACT The Five-hundred-meter Aperture Spherical radio Telescope (FAST) has started the Commensal Radio Astronomy FasT Survey (CRAFTS). In this paper, we use the technical parameters of FAST derived from commissioning observations to simulate the completeness function for extragalactic H i survey of CRAFTS, H i galaxies from two kinds of mock catalogues are selected. One is generated by Monte Carlo simulation based on the interpolated mass–velocity width function of the ALFALFA $100{{\ \rm per\ cent}}$ (a.k.a. α.100) catalogue. The other is constructed by semi-analytical N-body simulation based on the ΛCDM model. Our results suggest that a two-pass CRAFTS extragalactic H i survey will be able to detect nearly 4.8 × 105 galaxies, from which the ‘faint end’ slope of the H i mass function (HIMF) can be recovered to $\mathrm{10^{7}\, M_{\odot }}$ and the ‘knee mass’ of the HIMF can be measured to a redshift of 0.1. Considering the radio frequency interference status and sensitivity limitation, CRAFTS will be efficient in detecting H i galaxies at redshifts below 0.1, which implies a tremendous potential in exploring the galaxy interactions in different environments and the spatial distribution of H i galaxies in the local universe.

scholarly journals The H i mass function of group galaxies in the ALFALFA survey

2020 ◽  
Vol 494 (2) ◽  
pp. 2090-2108 ◽  
Author(s):  
Michael G Jones ◽  
Kelley M Hess ◽  
Elizabeth A K Adams ◽  
Lourdes Verdes-Montenegro
Keyword(s):  
Mass Function ◽  
Sloan Digital Sky Survey ◽  
Small Samples ◽  
Small Contribution ◽  
Galaxy Groups ◽  
Sky Survey ◽  
The Galaxy ◽  
Low Mass ◽  
Knee Mass ◽  
Group Galaxy

ABSTRACT We estimate the H i mass function (HIMF) of galaxies in groups based on thousands of ALFALFA (Arecibo Legacy Fast ALFA survey) H i detections within the galaxy groups of four widely used SDSS (Sloan Digital Sky Survey) group catalogues. Although differences between the catalogues mean that there is no one definitive group galaxy HIMF, in general we find that the low-mass slope is flat, in agreement with studies based on small samples of individual groups, and that the ‘knee’ mass is slightly higher than that of the global HIMF of the full ALFALFA sample. We find that the observed fraction of ALFALFA galaxies in groups is approximately 22 per cent. These group galaxies were removed from the full ALFALFA source catalogue to calculate the field HIMF using the remaining galaxies. Comparison between the field and group HIMFs reveals that group galaxies make only a small contribution to the global HIMF as most ALFALFA galaxies are in the field, but beyond the HIMF ‘knee’ group galaxies dominate. Finally, we attempt to separate the group galaxy HIMF into bins of group halo mass, but find that too few low-mass galaxies are detected in the most massive groups to tightly constrain the slope, owing to the rarity of such groups in the nearby Universe where low-mass galaxies are detectable with existing H i surveys.

scholarly journals Poor Groups Around Strong Gravitational Lenses

2006 ◽  
Vol 2 (S235) ◽  
pp. 230-230
Author(s):  
Ivelina Momcheva ◽  
Kurtis Williams ◽  
Ann Zabludoff ◽  
Charles Keeton
Keyword(s):  
Galaxy Evolution ◽  
Velocity Dispersion ◽  
Gravitational Lenses ◽  
Local Universe ◽  
Groups Of Galaxies ◽  
Hot Gas ◽  
Gas Kinematics ◽  
The Galaxy ◽  
Group Centroid ◽  
Group Galaxy

AbstractPoor groups are common and interactive environments for galaxies, and thus are important laboratories for studying galaxy evolution. Unfortunately, little is known about groups at z ≥ 0.1, because of the difficulty in identifying them in the first place. Here we present results from our ongoing survey of the environments of strong gravitational lenses, in which we have so far discovered six distant (z ≥ 0.5) groups of galaxies. As in the local Universe, the highest velocity dispersion groups contain a brightest member spatially coincident with the group centroid, whereas lower-dispersion groups tend to have an offset brightest group galaxy. This suggests that higher-dispersion groups are more dynamically relaxed than lower-dispersion groups and that at least some evolved groups exist by z ~ 0.5. We also compare the galaxy and hot gas kinematics with those of similarly distant clusters and of nearby groups.

scholarly journals The Bimodality of Galaxy Populations Revisited Through Spectral Synthesis

2006 ◽  
Vol 2 (S235) ◽  
pp. 139-139
Author(s):  
L. Sodré ◽  
A. Mateus ◽  
R. Cid Fernandes ◽  
G. Stasińska ◽  
W. Schoenell ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Spectral Synthesis ◽  
Synthesis Method ◽  
Local Universe ◽  
Massive Galaxies ◽  
Star Forming ◽  
The Galaxy ◽  
Galaxy Populations ◽  
Galaxy Population ◽  
Stellar Masses

AbstractWe revisit the bimodality of the galaxy population seen in the local universe. We address this issue in terms of physical properties of galaxies, such as mean stellar ages and stellar masses, derived from the application of a spectral synthesis method to galaxy spectra from the SDSS. We show that the mean light-weighted stellar age of galaxies presents the best description of the bimodality seen in the galaxy population. The stellar mass has an additional role since most of the star-forming galaxies present in the local universe are low-mass galaxies. Our results give support to the existence of a ‘downsizing’ in galaxy formation, where nowadays massive galaxies tend to have stellar populations older than those found in less massive objects.

scholarly journals Erratum: Deconstructing the Galaxy stellar mass function with UKIDSS and CANDELS: the impact of colour, structure and environment

2016 ◽  
Vol 458 (4) ◽  
pp. 3478-3478 ◽  
Author(s):  
Alice Mortlock ◽  
Christopher. J. Conselice ◽  
William G. Hartley ◽  
Ken Duncan ◽  
Caterina Lani ◽  
...  
Keyword(s):  
Mass Function ◽  
Stellar Mass ◽  
The Galaxy ◽  
The Impact

scholarly journals Spectral energy distribution similarity of the local galaxies and the 3.6 μm selected galaxies from the Spitzer Extended Deep Survey

2021 ◽  
Vol 21 (10) ◽  
pp. 260
Author(s):  
Cheng Cheng ◽  
Jia-Sheng Huang ◽  
Hai Xu ◽  
Gao-Xiang Jin ◽  
Chuan He ◽  
...  
Keyword(s):  
High Redshift ◽  
Spectral Energy Distribution ◽  
Mass Function ◽  
Spectral Energy ◽  
Energy Distributions ◽  
Mid Infrared ◽  
Redshift Galaxy ◽  
The Galaxy ◽  
Deep Survey ◽  
Multi Wavelength

Abstract The Spitzer Extended Deep Survey (SEDS) as a deep and wide mid-infrared (MIR) survey project provides a sample of 500 000+ sources spreading 1.46 square degree and a depth of 26 AB mag (3σ). Combining with the previous available data, we build a PSF-matched multi-wavelength photometry catalog from u band to 8 μm. We fit the SEDS galaxies spectral energy distributions by the local galaxy templates. The results show that the SEDS galaxy can be fitted well, indicating the high redshift galaxy (z ∼ 1) shares the same templates with the local galaxies. This study would facilitate the further study of the galaxy luminosity and high redshift mass function.

scholarly journals The Arches cluster revisited

2019 ◽  
Vol 623 ◽  
pp. A84 ◽  
Author(s):  
J. S. Clark ◽  
M. E. Lohr ◽  
L. R. Patrick ◽  
F. Najarro
Keyword(s):  
Main Sequence ◽  
Mass Function ◽  
Initial Mass Function ◽  
Galactic Centre ◽  
Complete Dataset ◽  
Subsequent Determination ◽  
The Galaxy ◽  
First Time ◽  
Massive Clusters

The Arches is one of the youngest, densest and most massive clusters in the Galaxy. As such it provides a unique insight into the lifecycle of the most massive stars known and the formation and survival of such stellar aggregates in the extreme conditions of the Galactic Centre. In a previous study we presented an initial stellar census for the Arches and in this work we expand upon this, providing new and revised classifications for ∼30% of the 105 spectroscopically identified cluster members as well as distinguishing potential massive runaways. The results of this survey emphasise the homogeneity and co-evality of the Arches and confirm the absence of H-free Wolf-Rayets of WC sub-type and predicted luminosities. The increased depth of our complete dataset also provides significantly better constraints on the main sequence population; with the identification of O9.5 V stars for the first time we now spectroscopically sample stars with initial masses ranging from ∼16 M⊙ to ≥120 M⊙. Indeed, following from our expanded stellar census we might expect ≳50 stars within the Arches to have been born with masses ≳60 M⊙, while all 105 spectroscopically confirmed cluster members are massive enough to leave relativistic remnants upon their demise. Moreover the well defined observational properties of the main sequence cohort will be critical to the construction of an extinction law appropriate for the Galactic Centre and consequently the quantitative analysis of the Arches population and subsequent determination of the cluster initial mass function.

The K-Band Luminosity Function of Galaxies

1998 ◽  
Vol 179 ◽  
pp. 278-280
Author(s):  
J. P. Gardner ◽  
R. M. Sharples ◽  
C. S. Frenk ◽  
B. E. Carrasco
Keyword(s):  
Luminosity Function ◽  
Near Infrared ◽  
Mass Function ◽  
Solar Mass ◽  
The Galaxy ◽  
Statistical Studies ◽  
The Absolute ◽  
Number Counts ◽  
Luminosity Evolution ◽  
K Band

The luminosity function of galaxies is central to many problems in cosmology, including the interpretation of faint number counts. The near-infrared provides several advantages over the optical for statistical studies of galaxies, including smooth and well-understood K-corrections and expected luminosity evolution. The K–band is dominated by near-solar mass stars which make up the bulk of the galaxy. The absolute K magnitude is a measure of the visible mass in a galaxy, and thus the K–band luminosity function is an observational counterpart of the mass function of galaxies.

scholarly journals Galactic starburst NGC 3603 from X-rays to radio

2003 ◽  
Vol 212 ◽  
pp. 515-522
Author(s):  
Anthony F.J. Moffat ◽  
Keyword(s):  
Mass Function ◽  
Initial Mass Function ◽  
X Rays ◽  
Stellar Content ◽  
Near Ir ◽  
The Galaxy ◽  
The Status ◽  
H Ii Region ◽  
Mass Segregation ◽  
Colliding Winds

While NGC 3603 is often quoted as the most massive visible Giant H ii Region in the Galaxy, there are other similar and even more massive regions now being found towards the inner Galaxy in the near-IR. Nevertheless, NGC 3603 still retains the status of clone to the dense core-object in 30 Dor, R 136 — but 7x closer and 49x less crowded! This paper summarizes the most recent findings concerning NGC 3603's color-magnitude diagram (CMD), initial mass function (IMF), mass segregation and stellar content — including its unusually luminous H-rich WNL members — down to its pre-main-sequence stars near the H-burning limit. Of special relevance are new high-resolution X-ray and radio images as related to merging/colliding winds and three massive proplyd-like objects. NGC 3603 is a somewhat younger, hotter, scaled-down version of typical starbursts found in other galaxies.

scholarly journals The XXL Survey

2018 ◽  
Vol 620 ◽  
pp. A7 ◽  
Author(s):  
V. Guglielmo ◽  
B. M. Poggianti ◽  
B. Vulcani ◽  
C. Adami ◽  
F. Gastaldello ◽  
...  
Keyword(s):  
Mass Function ◽  
Stellar Mass ◽  
X Ray ◽  
Field Versus ◽  
Final Sample ◽  
Wide Range ◽  
The Galaxy ◽  
Halo Masses ◽  
Stellar Masses ◽  
Physical Phenomena

Context. The fraction of galaxies bound in groups in the nearby Universe is high (50% at z ~ 0). Systematic studies of galaxy properties in groups are important in order to improve our understanding of the evolution of galaxies and of the physical phenomena occurring within this environment. Aims. We have built a complete spectrophotometric sample of galaxies within X-ray detected, optically spectroscopically confirmed groups and clusters (G&C), covering a wide range of halo masses at z ≤ 0.6. Methods. In the context of the XXL survey, we analyse a sample of 164 G&C in the XXL-North region (XXL-N), at z ≤ 0.6, with a wide range of virial masses (1.24 × 1013 ≤ M500,scal(M⊙) ≤ 6.63 × 1014) and X-ray luminosities ((2.27 × 1041 ≤ L500,scalXXL(erg s−1) ≤ 2.15 × 1044)). The G&C are X-ray selected and spectroscopically confirmed. We describe the membership assignment and the spectroscopic completeness analysis, and compute stellar masses. As a first scientific exploitation of the sample, we study the dependence of the galaxy stellar mass function (GSMF) on global environment. Results. We present a spectrophotometric characterisation of the G&C and their galaxies. The final sample contains 132 G&C, 22 111 field galaxies and 2225 G&C galaxies with r-band magnitude <20. Of the G&C, 95% have at least three spectroscopic members, and 70% at least ten. The shape of the GSMF seems not to depend on environment (field versus G&C) or X-ray luminosity (used as a proxy for the virial mass of the system). These results are confirmed by the study of the correlation between mean stellar mass of G&C members and L500,scalXXL. We release the spectrophotometric catalogue of galaxies with all the quantities computed in this work. Conclusions. As a first homogeneous census of galaxies within X-ray spectroscopically confirmed G&C at these redshifts, this sample will allow environmental studies of the evolution of galaxy properties.

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