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101. CALIFA galaxies O/H and N/O slopes
ID:
ivo://CDS.VizieR/J/A+A/595/A62
Title:
CALIFA galaxies O/H and N/O slopes
Short Name:
J/A+A/595/A62
Date:
21 Oct 2021
Publisher:
CDS
Description:
The study of the integrated properties of star-forming galaxies is central to understand their formation and evolution. Some of these properties are extensive and therefore their analysis require totally covering and spatially resolved observations. Among these properties, metallicity can be defined in spiral discs by means of integral field spectroscopy (IFS) of individual HII regions. The simultaneous analysis of the abundances of primary elements, as oxygen, and secondary, as nitrogen, also provides clues about the star formation history and the processes that shape the build-up of spiral discs. Our main aim is to analyse simultaneously O/H and N/O abundance ratios in HII regions in different radial positions of the discs in a large sample of spiral galaxies to obtain the slopes and the characteristic abundance ratios that can be related to their integrated properties. We analysed the optical spectra of individual selected HII regions extracted from a sample of 350 spiral galaxies of the CALIFA survey. We calculated total O/H abundances and, for the first time, N/O ratios using the semi-empirical routine HII-CHI-MISTRY, which, according to Perez-Montero (2014MNRAS.441.2663P), is consistent with the direct method and reduces the uncertainty in the O/H derivation using [NII] lines owing to the dispersion in the O/H-N/O relation. Then we performed linear fittings to the abundances as a function of the de-projected galactocentric distances.
102. CALIFA galaxies stellar angular momentum
ID:
ivo://CDS.VizieR/J/A+A/632/A59
Title:
CALIFA galaxies stellar angular momentum
Short Name:
J/A+A/632/A59
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the apparent stellar angular momentum over the optical extent of 300 galaxies across the Hubble sequence using integral-field spectroscopic (IFS) data from the CALIFA survey. Adopting the same {lambda}_R_ parameter previously used to distinguish between slow and fast rotating early-type (elliptical and lenticular) galaxies, we show that spiral galaxies are almost all fast rotators, as expected. Given the extent of our data, we provide relations for {lambda}_R_ measured in different apertures (e.g. fractions of the effective radius: 0.5R_e_, R_e_, 2R_e_), including conversions to long-slit 1D apertures. Our sample displays a wide range of {lambda}_Re_ values, consistent with previous IFS studies. The fastest rotators are dominated by relatively massive and highly star-forming Sb galaxies, which preferentially reside in the main star-forming sequence. These galaxies reach {lambda}_Re_ values of ~0.85, and they are the largest galaxies at a given mass, while also displaying some of the strongest stellar population gradients. Compared to the population of S0 galaxies, our findings suggest that fading may not be the dominant mechanism transforming spirals into lenticulars. Interestingly, we find that {lambda}_Re_ decreases for late-type Sc and Sd spiral galaxies, with values that occasionally set them in the slow-rotator regime. While for some of them this can be explained by their irregular morphologies and/or face-on configurations, others are edge-on systems with no signs of significant dust obscuration. The latter are typically at the low-mass end, but this does not explain their location in the classical (V/{sigma}, {epsilon}) and ({lambda}_Re_, {epsilon}) diagrams. Our initial investigations, based on dynamical models, suggest that these are dynamically hot disks, probably influenced by the observed important fraction of dark matter within R_e_.
103. CALIFA survey across the Hubble sequence
ID:
ivo://CDS.VizieR/J/A+A/581/A103
Title:
CALIFA survey across the Hubble sequence
Short Name:
J/A+A/581/A103
Date:
21 Oct 2021
Publisher:
CDS
Description:
Various different physical processes contribute to the star formation and stellar mass assembly histories of galaxies. One important approach to understanding the significance of these different processes on galaxy evolution is the study of the stellar population content of today's galaxies in a spatially resolved manner. The aim of this paper is to characterize in detail the radial structure of stellar population properties of galaxies in the nearby universe, based on a uniquely large galaxy sample, considering the quality and coverage of the data. The sample under study was drawn from the CALIFA survey and contains 300 galaxies observed with integral field spectroscopy. These cover a wide range of Hubble types, from spheroids to spiral galaxies, while stellar masses range from M_*_~10^9^ to 7x10^11^M_{sun}_. We apply the fossil record method based on spectral synthesis techniques to recover the following physical properties for each spatial resolution element in our target galaxies: the stellar mass surface density ({mu}_*_), stellar extinction (A_V_), light-weighted and mass-weighted ages (<logage>_L_, <logage>_M_), and mass-weighted metallicity (<logZ_*_>_M_). To study mean trends with overall galaxy properties, the individual radial profiles are stacked in seven bins of galaxy morphology (E, S0, Sa, Sb, Sbc, Sc, and Sd). We confirm that more massive galaxies are more compact, older, more metal rich, and less reddened by dust. Additionally, we find that these trends are preserved spatially with the radial distance to the nucleus. Deviations from these relations appear correlated with Hubble type: earlier types are more compact, older, and more metal rich for a given M_*_, which is evidence that quenching is related to morphology, but not driven by mass. Negative gradients of <logage>_L_ are consistent with an inside-out growth of galaxies, with the largest <logage>_L_ gradients in Sb-Sbc galaxies. Further, the mean stellar ages of disks and bulges are correlated and with disks covering a wider range of ages, and late-type spirals hosting younger disks. However, age gradients are only mildly negative or flat beyond R~2HLR (half light radius), indicating that star formation is more uniformly distributed or that stellar migration is important at these distances. The gradients in stellar mass surface density depend mostly on stellar mass, in the sense that more massive galaxies are more centrally concentrated. Whatever sets the concentration indices of galaxies obviously depends less on quenching/morphology than on the depth of the potential well. There is a secondary correlation in the sense that at the same M_*_ early-type galaxies have steeper gradients. The {mu}_*_ gradients outside 1HLR show no dependence on Hubble type. We find mildly negative <logZ_*_>_M_ gradients, which are shallower than predicted from models of galaxy evolution in isolation. In general, metallicity gradients depend on stellar mass, and less on morphology, hinting that metallicity is affected by both - the depth of the potential well and morphology/quenching. Thus, the largest <logZ_*_>_M_ gradients occur in Milky Way-like Sb-Sbc galaxies, and are similar to those measured above the Galactic disk. Sc spirals show flatter <logZ_*_>_M_ gradients, possibly indicating a larger contribution from secular evolution in disks. The galaxies from the sample have decreasing-outward stellar extinction; all spirals show similar radial profiles, independent from the stellar mass, but redder than E and S0. Overall, we conclude that quenching processes act in manners that are independent of mass, while metallicity and galaxy structure are influenced by mass-dependent processes.
104. CALIFA Survey DR3 list of galaxies
ID:
ivo://CDS.VizieR/J/A+A/594/A36
Title:
CALIFA Survey DR3 list of galaxies
Short Name:
J/A+A/594/A36
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper describes the third public data release (DR3) of the Calar Alto Legacy Integral Field Area (CALIFA) survey. Science-grade quality data for 667 galaxies are made public, including the 200 galaxies of the second public data release (DR2). Data were obtained with the integral-field spectrograph PMAS/PPak mounted on the 3.5m telescope at the Calar Alto Observatory. Three different spectral setups are available: i) a low-resolution V500 setup covering the wavelength range 3745-7500{AA} (4240-7140{AA} unvignetted) with a spectral resolution of 6.0{AA} (FWHM) for 646 galaxies, ii) a medium-resolution V1200 setup covering the wavelength range 3650-4840{AA} (3650-4620{AA} unvignetted) with a spectral resolution of 2.3{AA} (FWHM) for 484 galaxies, and iii) the combination of the cubes from both setups (called COMBO) with a spectral resolution of 6.0{AA} and a wavelength range between 3700-7500{AA} (3700-7140{AA} unvignetted) for 446 galaxies. The Main Sample, selected and observed according to the CALIFA survey strategy covers a redshift range between 0.005 and 0.03, spans the color-magnitude diagram and probes a wide range of stellar masses, ionization conditions, and morphological types. The Extension Sample covers several types of galaxies that are rare in the overall galaxy population and are therefore not numerous or absent in the CALIFA Main Sample. All the cubes in the data release were processed using the latest pipeline, which includes improved versions of the calibration frames and an even further improved image reconstruction quality. In total, the third data release contains 1576 datacubes, including ~1.5 million independent spectra.
105. Caltech Faint Galaxy Redshift Survey. XIV
ID:
ivo://CDS.VizieR/J/AJ/120/2190
Title:
Caltech Faint Galaxy Redshift Survey. XIV
Short Name:
J/AJ/120/2190
Date:
21 Oct 2021
Publisher:
CDS
Description:
Morphological classifications are reported for Hubble Space Telescope images of 241 galaxies in the Hubble Deep Field and its flanking fields with measured redshifts in the interval 0.25<z<1.2, drawn from a magnitude-limited redshift survey to R=24.0. The galaxies are divided into three groups with redshifts in the intervals 0.25-0.6, 0.6-0.8, and 0.8-1.2. R_606_ images from the first group and I814 images from the second and third groups are compared with B-band images of nearby galaxies. All classifications were therefore made at approximately the same rest wavelength. Selection biases are discussed.
106. Caltech Faint Galaxy Redshift Survey. XV.
ID:
ivo://CDS.VizieR/J/AJ/122/611
Title:
Caltech Faint Galaxy Redshift Survey. XV.
Short Name:
J/AJ/122/611
Date:
21 Oct 2021
Publisher:
CDS
Description:
To circumvent the spatial effects of resolution on galaxy classification, the images of 233 objects of known redshift in the Hubble Deep Field (HDF) and its flanking fields that have redshifts in the range 0.20<z<1.10 were degraded to the resolution that they would have had if they were all located at a redshift of z=1.00. As in Paper XIV (Cat. <J/AJ/120/2190>) of the present series, the effects of shifts in rest wavelength were mitigated by using R-band images for the classification of galaxies with 0.2<z<0.6 and I-band images for objects with redshifts 0.6<z<1.1. A special effort was made to search for bars in distant galaxies. The present data strongly confirm the previous conclusion that the Hubble tuning fork diagram only provides a satisfactory framework for the classification of galaxies with z<0.3. More distant disk galaxies are often difficult to shoehorn into the Hubble classification scheme. The paucity of barred spirals and grand-design spirals at large redshifts is confirmed. It is concluded that the morphology of disk galaxies observed at look-back times smaller than 3-4Gyr differs systematically from that of more distant galaxies viewed at look-back times of 4-8Gyr. The disks of late-type spirals at z>0.5 are seen to be more chaotic than those of their nearer counterparts. Furthermore, the spiral structure in distant early-type spirals appears to be less well developed than it is in nearby early galaxies.
107. CALYMHA survey. I.
ID:
ivo://CDS.VizieR/J/MNRAS/466/1242
Title:
CALYMHA survey. I.
Short Name:
J/MNRAS/466/1242
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the CAlibrating LYMan-{alpha} with H{alpha} (CALYMHA) pilot survey and new results on Lyman {alpha} (Ly{alpha}) selected galaxies at z~2. We use a custom-built Ly{alpha} narrow-band filter at the Isaac Newton Telescope, designed to provide a matched volume coverage to the z=2.23H{alpha} HiZELS survey. Here, we present the first results for the COSMOS and UDS fields. Our survey currently reaches a 3{sigma} line flux limit of ~4x10^-17^erg/s/cm^2^, and a Ly{alpha} luminosity limit of ~10^42.3^erg/s. We find 188 Ly{alpha} emitters over 7.3x10^5^Mpc^3^, but also find significant numbers of other line-emitting sources corresponding to HeII, CIII] and CIV emission lines. These sources are important contaminants, and we carefully remove them, unlike most previous studies. We find that the Ly{alpha} luminosity function at z=2.23 is very well described by a Schechter function up to L_Ly{alpha}_~=10^43^erg/s^ with L*=10^42.59(10^42.75^-10^42.01^)erg/s, {phi}*=10^-3.09^(10^-3.43^-10^2.95)Mpc^-3^ and {alpha}=-1.75+/-0.25. Above L_Ly{alpha}_~=10^43^erg/s, the Ly{alpha} luminosity function becomes power-law like, driven by X-ray AGN. We find that Ly{alpha}-selected emitters have a high escape fraction of 37+/-7 per cent, anticorrelated with Ly{alpha} luminosity and correlated with Ly{alpha} equivalent width. Ly{alpha} emitters have ubiquitous large (~=40kpc) Ly{alpha} haloes, ~2 times larger than their H{alpha} extents. By directly comparing our Ly{alpha} and H{alpha} luminosity functions, we find that the global/overall escape fraction of Ly{alpha} photons (within a 13kpc radius) from the full population of star-forming galaxies is 5.1+/-0.2 per cent at the peak of the star formation history. An extra 3.3+/-0.3 per cent of Ly{alpha} photons likely still escape, but at larger radii.
108. CANDELS galaxy structure classification
ID:
ivo://CDS.VizieR/J/MNRAS/458/963
Title:
CANDELS galaxy structure classification
Short Name:
J/MNRAS/458/963
Date:
21 Oct 2021
Publisher:
CDS
Description:
Important but rare and subtle processes driving galaxy morphology and star formation may be missed by traditional spiral, elliptical, irregular or Sersic bulge/disc classifications. To overcome this limitation, we use a principal component analysis (PCA) of non-parametric morphological indicators (concentration, asymmetry, Gini coefficient, M_20_, multimode, intensity and deviation) measured at rest-frame B band (corresponding to HST/WFC3 F125W at 1.4<z<2) to trace the natural distribution of massive (>10^10^M_{sun}_) galaxy morphologies. PCA quantifies the correlations between these morphological indicators and determines the relative importance of each. The first three principal components (PCs) capture ~75 per cent of the variance inherent to our sample. We interpret the first PC as bulge strength, the second PC as dominated by concentration and the third PC as dominated by asymmetry. Both PC1 and PC2 correlate with the visual appearance of a central bulge and predict galaxy quiescence. PC1 is a better predictor of quenching than stellar mass, as good as other structural indicators (Sersic-n or compactness). We divide the PCA results into groups using an agglomerative hierarchical clustering method. Unlike Sersic, this classification scheme separates compact galaxies from larger, smooth protoelliptical systems, and star-forming disc-dominated clumpy galaxies from star-forming bulge-dominated asymmetric galaxies. Distinguishing between these galaxy structural types in a quantitative manner is an important step towards understanding the connections between morphology, galaxy assembly and star formation.
109. CANDELS visual classifications for GOODS-S
ID:
ivo://CDS.VizieR/J/ApJS/221/11
Title:
CANDELS visual classifications for GOODS-S
Short Name:
J/ApJS/221/11
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have undertaken an ambitious program to visually classify all galaxies in the five CANDELS fields down to H<24.5 involving the dedicated efforts of over 65 individual classifiers. Once completed, we expect to have detailed morphological classifications for over 50000 galaxies spanning 0<z<4 over all the fields, with classifications from 3 to 5 independent classifiers for each galaxy. Here, we present our detailed visual classification scheme, which was designed to cover a wide range of CANDELS science goals. This scheme includes the basic Hubble sequence types, but also includes a detailed look at mergers and interactions, the clumpiness of galaxies, k-corrections, and a variety of other structural properties. In this paper, we focus on the first field to be completed --GOODS-S, which has been classified at various depths. The wide area coverage spanning the full field (wide+deep+ERS) includes 7634 galaxies that have been classified by at least three different people. In the deep area of the field, 2534 galaxies have been classified by at least five different people at three different depths. With this paper, we release to the public all of the visual classifications in GOODS-S along with the Perl/Tk GUI that we developed to classify galaxies. We present our initial results here, including an analysis of our internal consistency and comparisons among multiple classifiers as well as a comparison to the Sersic index. We find that the level of agreement among classifiers is quite good (>70% across the full magnitude range) and depends on both the galaxy magnitude and the galaxy type, with disks showing the highest level of agreement (>50%) and irregulars the lowest (<10%). A comparison of our classifications with the Sersic index and rest-frame colors shows a clear separation between disk and spheroid populations. Finally, we explore morphological k-corrections between the V-band and H-band observations and find that a small fraction (84 galaxies in total) are classified as being very different between these two bands. These galaxies typically have very clumpy and extended morphology or are very faint in the V-band.
110. CANDELS z~2 galaxy properties
ID:
ivo://CDS.VizieR/J/ApJ/793/101
Title:
CANDELS z~2 galaxy properties
Short Name:
J/ApJ/793/101
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use CANDELS imaging, 3D-HST spectroscopy, and Chandra X-ray data to investigate if active galactic nuclei (AGNs) are preferentially fueled by violent disk instabilities funneling gas into galaxy centers at 1.3<z<2.4. We select galaxies undergoing gravitational instabilities using the number of clumps and degree of patchiness as proxies. The CANDELS visual classification system is used to identify 44 clumpy disk galaxies, along with mass-matched comparison samples of smooth and intermediate morphology galaxies. We note that despite being mass-matched and having similar star formation rates, the smoother galaxies tend to be smaller disks with more prominent bulges compared to the clumpy galaxies. The lack of smooth extended disks is probably a general feature of the z~2 galaxy population, and means we cannot directly compare with the clumpy and smooth extended disks observed at lower redshift. We find that z~2 clumpy galaxies have slightly enhanced AGN fractions selected by integrated line ratios (in the mass-excitation method), but the spatially resolved line ratios indicate this is likely due to extended phenomena rather than nuclear AGNs. Meanwhile, the X-ray data show that clumpy, smooth, and intermediate galaxies have nearly indistinguishable AGN fractions derived from both individual detections and stacked non-detections. The data demonstrate that AGN fueling modes at z~1.85 - whether violent disk instabilities or secular processes - are as efficient in smooth galaxies as they are in clumpy galaxies.