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24831. z~6 galaxies UV luminosity function
ID:
ivo://CDS.VizieR/J/ApJ/653/53
Title:
z~6 galaxies UV luminosity function
Short Name:
J/ApJ/653/53
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have detected 506 i-dropouts (z~6 galaxies) in deep, wide-area HST ACS fields: HUDF, enhanced GOODS, and HUDF parallel ACS fields (HUDF-Ps). The contamination levels are <~8% (i.e., >~92% are at z~6). With these samples, we present the most comprehensive, quantitative analyses of z~6 galaxies yet and provide optimal measures of the UV luminosity function (LF) and luminosity density at z~6, and their evolution to z~3. We redetermine the size and color evolution from z~6 to z~3. Field-to-field variations (cosmic variance), completeness, flux, and contamination corrections are modeled systematically and quantitatively.
24832. z>1 galaxy clusters from IRAC Shallow Survey
ID:
ivo://CDS.VizieR/J/ApJ/684/905
Title:
z>1 galaxy clusters from IRAC Shallow Survey
Short Name:
J/ApJ/684/905
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have identified 335 galaxy cluster and group candidates, 106 of which are at z>1, using a 4.5um-selected sample of objects from a 7.25deg^2^ region in the Spitzer Infrared Array Camera (IRAC) Shallow Survey. Clusters were identified as three-dimensional overdensities using a wavelet algorithm, based on photometric redshift probability distributions derived from IRAC and NOAO Deep Wide-Field Survey data. We estimate only ~10% of the detections are spurious. To date 12 of the z>1 candidates have been confirmed spectroscopically, at redshifts from 1.06 to 1.41. Velocity dispersions of ~750km/s for two of these argue for total cluster masses well above 10^14^M_{sun}_, as does the mass estimated from the rest-frame near-infrared stellar luminosity. Although not selected to contain a red sequence, some evidence for red sequences is present in the spectroscopically confirmed clusters, and brighter galaxies are systematically redder than the mean galaxy color in clusters at all redshifts.
24833. 0.006<=z<=0.8 IR galaxies with AKARI
ID:
ivo://CDS.VizieR/J/PASJ/65/113
Title:
0.006<=z<=0.8 IR galaxies with AKARI
Short Name:
J/PASJ/65/113
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the 9 and 18um luminosity functions (LFs) of galaxies at 0.006<=z<=0.8 (with an average redshift of ~0.04) using the AKARI mid-infrared all-sky survey catalog. We selected 243 galaxies at 9um and 255 galaxies at 18um from the Sloan Digital Sky Survey (SDSS) spectroscopy region. These galaxies were then classified by their optical emission lines, such as the line width of H{alpha} or by their emission line ratios of [OIII]/H{beta} and [NII]/H{alpha} into five types: Type 1 active galactic nuclei (AGN) (Type 1); Type 2 AGN (Type 2); low-ionization narrow emission line galaxies (LINER); galaxies with both star formation and narrow-line AGN activity (composite galaxies); and star-forming galaxies (SF). We found that (i) the number density ratio of Type 2 to Type 1 AGNs is 1.73+/-0.36, which is larger than a result obtained from the optical LF and (ii) this ratio decreases with increasing 18um luminosity.
24834. ZJ VISTA photometry in NGC253 stellar halo
ID:
ivo://CDS.VizieR/J/A+A/562/A73
Title:
ZJ VISTA photometry in NGC253 stellar halo
Short Name:
J/A+A/562/A73
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use images obtained with the VISTA telescope in the Z and J bands to analyze the stellar content of NGC 253, a nearly edge on spiral galaxy in the Sculptor group. The very deep photometry, down to J~23.5, and the wide area covered allow us to trace the red giant branch and asymptotic giant branch (AGB) stars that belong to the outer disk and the halo of NGC 253, out to 50kpc along the galaxy minor axis. We confirm the existence of an extraplanar component, with a prominent southern shelf and detect for the first time a symmetrical feature on the north side. The star counts profile along the major axis show a clear break at 25kpc from the center, signalling the transition from the disk to the halo. The isodensity contours show a flat inner halo that blends with a more extended, diffuse, rounder outer halo. In such external structure, we detect an overdensity at about 28kpc from the plane and extending over 20kpc parallel with the disk of the galaxy. The spatially resolved color magnitude diagrams show a rather homogeneous stellar population across the tile. Particularly surprising is the presence of bright, intermediate age, AGB stars found scattered over a large volume.
24835. z=3.1 LAEs morphological properties
ID:
ivo://CDS.VizieR/J/ApJ/743/9
Title:
z=3.1 LAEs morphological properties
Short Name:
J/ApJ/743/9
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a morphological analysis of the rest-frame ultraviolet emission of 78 resolved, high signal-to-noise z~3.1 Ly{alpha} emitters (LAEs) in the Extended Chandra Deep Field-South. Using Hubble Space Telescope/Advanced Camera for Surveys V-band images taken as part of the Galaxy Evolution from Morphology and SEDs, Great Observatories Origins Deep Survey, and Hubble Ultra Deep Field surveys, we investigate both single-component and multi-component LAEs, and derive concentration indices, Sersic indices, ellipticities, and half-light radii for all resolved components and systems with a signal-to-noise >30. We show that, although the LAE population is heterogeneous in nature, most LAEs are highly concentrated, with a distribution of C values similar to that measured for field stars; this suggests that the diagnostic is a poor discriminator near the resolution limit. The LAEs also display a wide range of Sersic indices (0<n<12), similar to that seen for galaxies in the local neighborhood. However, the majority of LAEs have n<2, and a visual inspection of the images suggests that the small-n objects have extended or multimodal luminosity profiles, while the LAEs with n>2 have compact components surrounded by diffuse emission. Moreover, unlike nearby spiral galaxies, whose distribution of ellipticities is flat, the LAE ellipticity distribution peaks near 1-b/a~0.55. Thus, the population has more in common with z~3 Lyman-break galaxies than local star-forming objects.
24836. z-low satellite galaxies in COSMOS survey
ID:
ivo://CDS.VizieR/J/MNRAS/478/5336
Title:
z-low satellite galaxies in COSMOS survey
Short Name:
J/MNRAS/478/5336
Date:
10 Dec 2021 14:18:30
Publisher:
CDS
Description:
Faint dwarf satellite galaxies are important as tracers of small-scale structure, but remain poorly characterized outside the Local Group, due to the difficulty of identifying them consistently at larger distances. We review a recently proposed method for estimating the average satellite population around a given sample of nearby bright galaxies, using a combination of size and magnitude cuts (to select low-redshift dwarf galaxies preferentially) and clustering measurements (to estimate the fraction of true satellites in the cut sample). We test this method using the high-precision photometric redshift catalogue of the COSMOS survey, exploring the effect of specific cuts on the clustering signal. The most effective of the size-magnitude cuts considered recover the clustering signal around low-redshift primaries (z<0.15) with about two-thirds of the signal and 80 per cent of the signal-to-noise ratio obtainable using the full COSMOS photometric redshifts. These cuts are also fairly efficient, with more than one-third of the selected objects being clustered satellites. We conclude that structural selection represents a useful tool in characterizing dwarf populations to fainter magnitudes and/or over larger areas than are feasible with spectroscopic surveys. In reviewing the low-redshift content of the COSMOS field, we also note the existence of several dozen objects that appear resolved or partially resolved in the HST imaging, and are confirmed to be local (at distances of ~250Mpc or less) by their photometric or spectroscopic redshifts. This underlines the potential for future space-based surveys to reveal local populations of intrinsically faint galaxies through imaging alone.
24837. z~1 Ly{alpha} emitters. I. 135 candidates from GALEX
ID:
ivo://CDS.VizieR/J/ApJ/783/119
Title:
z~1 Ly{alpha} emitters. I. 135 candidates from GALEX
Short Name:
J/ApJ/783/119
Date:
21 Oct 2021
Publisher:
CDS
Description:
We construct a flux-limited sample of 135 candidate z~1 Ly{alpha} emitters (LAEs) from Galaxy Evolution Explorer (GALEX) grism data using a new data cube search method. These LAEs have luminosities comparable to those at high redshifts and lie within a 7Gyr gap present in existing LAE samples. We use archival and newly obtained optical spectra to verify the UV redshifts of these LAEs. We use the combination of the GALEX UV spectra, optical spectra, and X-ray imaging data to estimate the active galactic nucleus (AGN) fraction and its dependence on Ly{alpha} luminosity. We remove the AGNs and compute the luminosity function (LF) from 60 z~1 LAE galaxies. We find that the best-fit LF implies a luminosity density increase by a factor of ~1.5 from z~0.3 to z~1 and ~20 from z~1 to z~2. We find a z~1 volumetric Ly{alpha} escape fraction of 0.7%+/-0.4%.
24838. z=2.4 Ly{alpha} emitters in the 53W002 field
ID:
ivo://CDS.VizieR/J/ApJ/759/133
Title:
z=2.4 Ly{alpha} emitters in the 53W002 field
Short Name:
J/ApJ/759/133
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of our wide-field narrowband imaging of the field around the radio galaxy 53W002 at z=2.390 with Subaru/Suprime-Cam. A custom-made filter, NB413, centered at 4140{AA} with a width of 83{AA} is used to observe the 31'x24' area around the radio galaxy. We detected 204 Ly{alpha} emitters (LAEs) at z=2.4 with a rest-frame equivalent width larger than 25{AA} to the depth of 26 AB mag (in NB413). The entire LAE population in the 53W002 field has an average number density and distributions of equivalent width and size that are similar to those of other fields at z~2. We identify a significant high-density region (53W002F-HDR) that spreads over {approx}5'x4' near 53W002, where the LAE number density is nearly four times as large as the average of the entire field. Using the probability distribution function of density fluctuation, we evaluate the rareness probability of 53W002F-HDR to be 0.9^+2.4^_-0.62_%, which corresponds to a moderately rich structure. No notable environmental dependency at the comoving scale of 10Mpc is found for the distributions of the Ly{alpha} equivalent width and luminosity in the field. We also detected four Ly{alpha} blobs, one of which is newly discovered. They are all located in the rims of high-density regions. The biased location and unique morphologies in Ly{alpha} suggest that galaxy interaction plays a key role in their formation.
24839. z~4-7 Lyman break galaxies in Hubble deep fields
ID:
ivo://CDS.VizieR/J/ApJ/821/123
Title:
z~4-7 Lyman break galaxies in Hubble deep fields
Short Name:
J/ApJ/821/123
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present clustering analysis results from 10381 Lyman break galaxies (LBGs) at z~4-7, identified in the Hubble legacy deep imaging and new complimentary large-area Subaru/Hyper Suprime-Cam data. We measure the angular correlation functions of these LBGs at z~4, 5, 6, and 7 and fit these measurements using halo occupation distribution (HOD) models that provide an estimate of halo masses, M_h_~(1-20)x10^11^M_{sun}_. Our Mh estimates agree with those obtained by previous clustering studies in a UV-magnitude versus Mh plane and allow us to calculate stellar-to-halo mass ratios (SHMRs) of LBGs. By comparison with the z~0 SHMR, we identify evolution of the SHMR from z~0 to z~4 and from z~4 to z~7 at the >98% confidence levels. The SHMR decreases by a factor of ~2 from z~0 to 4 and increases by a factor of ~4 from z~4 to 7 at the dark matter halo mass of M_h_~10^11^M_{sun}. We compare our SHMRs with results of a hydrodynamic simulation and a semianalytic model and find that these theoretical studies do not predict the SHMR increase from z~4 to 7. We obtain the baryon conversion efficiency (BCE) of LBGs at z~4 and find that the BCE increases with increasing dark matter halo mass. Finally, we compare our clustering+HOD estimates with results from abundance matching techniques and conclude that the Mh estimates of the clustering+HOD analyses agree with those of the simple abundance matching within a factor of 3, and that the agreement improves when using more sophisticated abundance matching techniques that include subhalos, incompleteness, and/or evolution in the star formation and stellar mass functions.
24840. ZnI atomic data
ID:
ivo://CDS.VizieR/J/A+A/536/A51
Title:
ZnI atomic data
Short Name:
J/A+A/536/A51
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present our calculated data including energy levels of 235 bound terms, oscillator strength gf-values of E1 transitions between these bound states and photoionization cross sections of all the terms for Zn I. The energy levels are listed in the file "znibound.dat" by symmetries in Ry, and the oscillator strength gf-values are listed in the file "gfvalues.dat". The photoionization cross section of each bound states is listed in an individual file named by the corresponding state. In each file, the first column is the photon energy in Ry, and other columns are photoionization cross section in Mb.

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