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181. Cool stars chromospheric activity catalog
ID:
ivo://CDS.VizieR/J/A+A/616/A108
Title:
Cool stars chromospheric activity catalog
Short Name:
J/A+A/616/A108
Date:
21 Oct 2021
Publisher:
CDS
Description:
Chromospheric activity monitoring of a wide range of cool stars can provide valuable information on stellar magnetic activity and its dependence on fundamental stellar parameters such as effective temperature and rotation. We compile a chromospheric activity catalogue of 4454 cool stars from a combination of archival HARPS spectra and multiple other surveys, including the Mount Wilson data that have recently been released by the NSO. We explore the variation in chromospheric activity of cool stars along the main sequence for stars with different effective temperatures. Additionally, we also perform an activity-cycle period search and investigate its relation with rotation. The chromospheric activity index, S-index, was measured for 304 main-sequence stars from archived high-resolution HARPS spectra. Additionally, the measured and archived S-indices were converted into the chromospheric flux ratio logR'HK. The activity-cycle periods were determined using the generalised Lomb-Scargle periodogram to study the active and inactive branches on the rotation-activity-cycle period plane. The global sample shows that the bimodality of chromospheric activity, known as the Vaughan-Preston gap, is not prominent, with a significant percentage of the stars at an intermediate-activity level around logR'HK=-4.75. Independently, the cycle period search shows that stars can lie in the region intermediate between the active and inactive branch, which means that the active branch is not as clearly distinct as previously thought. The weakening of the Vaughan-Preston gap indicates that cool stars spin down from a higher activity level and settle at a lower activity level without a sudden break at intermediate activity. Some cycle periods are close to the solar value between the active and inactive branch, which suggests that the solar dynamo is most likely a common case of the stellar dynamo.
182. Corotation radii for 153 galaxies of OSUBSGS
ID:
ivo://CDS.VizieR/J/ApJS/182/559
Title:
Corotation radii for 153 galaxies of OSUBSGS
Short Name:
J/ApJS/182/559
Date:
21 Oct 2021
Publisher:
CDS
Description:
The potential-density phase-shift method (Zhang et al., 2007AJ....133.2584Z) is an effective new tool for investigating the structure and evolution of galaxies. In this paper, we apply the method to 153 galaxies in the Ohio State University Bright Galaxy Survey (OSUBGS) to study the general relationship between pattern corotation radii and the morphology of spiral galaxies. The analysis is based on near-infrared H-band images that have been deprojected and decomposed assuming a spherical bulge.
183. Cosmicflows-3 catalog (CF3)
ID:
ivo://CDS.VizieR/J/AJ/152/50
Title:
Cosmicflows-3 catalog (CF3)
Short Name:
J/AJ/152/50
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Cosmicflows database of galaxy distances that in the second edition contained 8188 entries is now expanded to 17669 entries. The major additions are 2257 distances that we have derived from the correlation between galaxy rotation and luminosity with photometry at 3.6{mu}m obtained with the Spitzer Space Telescope and 8885 distances based on the Fundamental Plane methodology from the Six Degree Field Galaxy Survey collaboration. There are minor augmentations to the Tip of the Red Giant Branch and Type Ia supernova compilations. A zero-point calibration of the supernova luminosities gives a value for the Hubble Constant of 76.2+/-3.4+/-2.7 (+/-rand.+/-sys.)km/s/Mpc. Alternatively, a restriction on the peculiar velocity monopole term representing global infall/outflow implies H_0_=75+/-2km/s/Mpc.
184. Cosmicflows-2 catalog (CF2)
ID:
ivo://CDS.VizieR/J/AJ/146/86
Title:
Cosmicflows-2 catalog (CF2)
Short Name:
J/AJ/146/86
Date:
21 Oct 2021
Publisher:
CDS
Description:
Cosmicflows-2 is a compilation of distances and peculiar velocities for over 8000 galaxies. Numerically the largest contributions come from the luminosity-line width correlation for spirals, the Tully-Fisher relation (TFR), and the related fundamental plane relation for E/S0 systems, but over 1000 distances are contributed by methods that provide more accurate individual distances: Cepheid, tip of the red giant branch (TRGB), surface brightness fluctuation, Type Ia supernova, and several miscellaneous but accurate procedures. Our collaboration is making important contributions to two of these inputs: TRGB and TFR. A large body of new distance material is presented. In addition, an effort is made to ensure that all the contributions, both our own and those from the literature, are on the same scale. Overall, the distances are found to be compatible with a Hubble constant H_0_=74.4+/-3.0km/s/Mpc. The great interest going forward with this data set will be with velocity field studies. Cosmicflows-2 is characterized by a great density and high accuracy of distance measures locally, falling to sparse and coarse sampling extending to z=0.1.
185. Cosmic web filaments in the SDSS
ID:
ivo://CDS.VizieR/J/MNRAS/438/3465
Title:
Cosmic web filaments in the SDSS
Short Name:
J/MNRAS/438/3465
Date:
21 Oct 2021
Publisher:
CDS
Description:
The main feature of the spatial large-scale galaxy distribution is its intricate network of galaxy filaments. This network is spanned by the galaxy locations that can be interpreted as a three-dimensional point distribution. The global properties of the point process can be measured by different statistical methods, which, however, do not describe directly the structure elements. The morphology of the large scale structure, on the other hand, is an important property of the galaxy distribution. Here we apply an object point process with interactions (the Bisous model) to trace and extract the filamentary network in the presently largest galaxy redshift survey, the Sloan Digital Sky Survey (SDSS). We search for filaments in the galaxy distribution that have a radius of about 0.5Mpc/h. We divide the detected network into single filaments and present a public catalogue of filaments. We study the filament length distribution and show that the longest filaments reach the length of 60Mpc/h. The filaments contain 35-40% of the total galaxy luminosity and they cover roughly 5-8% of the total volume, in good agreement with N-body simulations and previous observational results.
186. Cosmic web of galaxies in the COSMOS field
ID:
ivo://CDS.VizieR/J/ApJ/837/16
Title:
Cosmic web of galaxies in the COSMOS field
Short Name:
J/ApJ/837/16
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use a mass complete (log(M/M_{sun}_)>=9.6) sample of galaxies with accurate photometric redshifts in the COSMOS field to construct the density field and the cosmic web to z=1.2. The comic web extraction relies on the density field Hessian matrix and breaks the density field into clusters, filaments, and the field. We provide the density field and cosmic web measures to the community. We show that at z<~0.8, the median star formation rate (SFR) in the cosmic web gradually declines from the field to clusters and this decline is especially sharp for satellites (~1dex versus ~0.5dex for centrals). However, at z>~0.8, the trend flattens out for the overall galaxy population and satellites. For star-forming (SF) galaxies only, the median SFR is constant at z>~0.5 but declines by ~0.3-0.4dex from the field to clusters for satellites and centrals at z<~0.5. We argue that for satellites, the main role of the cosmic web environment is to control their SF fraction, whereas for centrals, it is mainly to control their overall SFR at z<~0.5 and to set their fraction at z>~0.5. We suggest that most satellites experience a rapid quenching mechanism as they fall from the field into clusters through filaments, whereas centrals mostly undergo a slow environmental quenching at z<~0.5 and a fast mechanism at higher redshifts. Our preliminary results highlight the importance of the large-scale cosmic web on galaxy evolution.
187. Cosmology from galaxy lensing and clustering
ID:
ivo://CDS.VizieR/J/A+A/627/A137
Title:
Cosmology from galaxy lensing and clustering
Short Name:
J/A+A/627/A137
Date:
21 Oct 2021
Publisher:
CDS
Description:
The combination of Galaxy-Galaxy Lensing (GGL) and Redshift Space Distortion of galaxy clustering (RSD) is a privileged technique to test General Relativity predictions, and break degeneracies between the growth rate of structure parameter f and the amplitude of the linear power-spectrum {sigma}8. We perform a joint GGL and RSD analysis on 250 sq. degrees using shape catalogues from CFHTLenS and CFHT-Stripe 82, and spectroscopic redshifts from the BOSS CMASS sample. We adjust a model that includes non-linear biasing, RSD and Alcock-Paczynski effects. We find f(z=0.57)=0.95+/-0.23, {sigma}8(z=0.57)=0.55+/-0.07 and {OMEGA}m=0.31+/-0.08, in agreement with Planck cosmological results 2018. We also estimate the probe of gravity E_G_=0.43+/-0.10 in agreement with {LAMBDA}CDM-GR predictions of E_G_=0.40. This analysis reveals that RSD efficiently decreases the GGL uncertainty on {OMEGA}m by a factor of 4, and by 30% on {sigma}8. We use an N-body simulation supplemented by an abundance matching prescription for CMASS to build a set of overlapping lensing and clustering mocks. Together with additional spectroscopic data, this helps us to quantify and correct several systematic errors, such as photometric redshifts. We make our mock catalogues available on the Skies and Universe database.
188. COSMOS2015 dataset machine learning photo-z
ID:
ivo://CDS.VizieR/J/MNRAS/507/5034
Title:
COSMOS2015 dataset machine learning photo-z
Short Name:
J/MNRAS/507/5034
Date:
03 Dec 2021 13:07:03
Publisher:
CDS
Description:
In order to answer the open questions of modern cosmology and galaxy evolution theory, robust algorithms for calculating photometric redshifts (photo-z) for very large samples of galaxies are needed. Correct estimation of the various photo-z algorithms' performance requires attention to both the performance metrics and the data used for the estimation. In this work, we use the supervised machine learning algorithm MLPQNA (Multi-Layer Perceptron with Quasi-Newton Algorithm) to calculate photometric redshifts for the galaxies in the COSMOS2015 catalogue and the unsupervised Self-Organizing Maps (SOM) to determine the reliability of the resulting estimates. We find that for z_spec_<1.2, MLPQNA photo-z predictions are on the same level of quality as spectral energy distribution fitting photo-z. We show that the SOM successfully detects unreliable zspec that cause biases in the estimation of the photo-z algorithms' performance. Additionally, we use SOM to select the objects with reliable photo-z predictions. Our cleaning procedures allow us to extract the subset of objects for which the quality of the final photo-z catalogues is improved by a factor of 2, compared to the overall statistics.
189. COSMOS Morphological Catalog (V1.1)
ID:
ivo://CDS.VizieR/VII/265
Title:
COSMOS Morphological Catalog (V1.1)
Short Name:
VII/265
Date:
21 Oct 2021
Publisher:
CDS
Description:
The zCOSMOS field benefits of high-resolution imaging in the F814W filter from the HST-ACS (Advanced Camera for Survey). We use standard morphology classifiers, optimised for being robust against band-shifting and surface brightness dimming, and a new, objective, and automated method to convert morphological parameters into early, spiral, and irregular types. We use about 10000 galaxies down to I(AB)=22.5mag with a spectroscopic sampling rate of 33% to characterise the environment of galaxies up to z~1 from the 100kpc scales of galaxy groups up to the 100Mpc scales of the cosmic web.
190. COSMOS photometric redshift catalog
ID:
ivo://CDS.VizieR/J/ApJ/690/1236
Title:
COSMOS photometric redshift catalog
Short Name:
J/ApJ/690/1236
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present accurate photometric redshifts (photo-z) in the 2-deg^2^ COSMOS field. The redshifts are computed with 30 broad, intermediate, and narrowbands covering the UV (Galaxy Evolution Explorer), visible near-IR (NIR; Subaru, Canada-France-Hawaii Telescope (CFHT), United Kingdom Infrared Telescope, and National Optical Astronomy Observatory), and mid-IR (Spitzer/IRAC). A {chi}^2^ template-fitting method (Le Phare) was used and calibrated with large spectroscopic samples from the Very Large Telescope Visible Multi-Object Spectrograph and the Keck Deep Extragalactic Imaging Multi-Object Spectrograph. We develop and implement a new method which accounts for the contributions from emission lines ([OII], H{beta}, H{alpha}, and Ly{alpha}) to the spectral energy distributions (SEDs). The treatment of emission lines improves the photo-z accuracy by a factor of 2.5. Comparison of the derived photo-z with 4148 spectroscopic redshifts (i.e., {Delta}z=zs-zp) indicates a dispersion of {sigma}_{Delta}z/(1+zs)_=0.007 at i^+^_AB_<22.5, a factor of 2-6 times more accurate than earlier photo-z in the COSMOS, CFHT Legacy Survey, and the Classifying Object by Medium-Band Observations-17 survey fields. At fainter magnitudes i^+^_AB_<24 and z<1.25, the accuracy is {sigma}_{Delta}z/(1+zs)_=0.012. The deep NIR and Infrared Array Camera coverage enables the photo-z to be extended to z~2, albeit with a lower accuracy ({sigma}_{Delta}z/(1+zs)_=0.006 at i^+^_AB_~24). The redshift distribution of large magnitude-selected samples is derived and the median redshift is found to range from z_m_= 0.66 at 22 <i^+^_AB_<22.5 to z_m_=1.06 at 24.5<i^+^_AB_<25. At i ^+^_AB_<26.0, the multiwavelength COSMOS catalog includes approximately 607,617 objects. The COSMOS-30 photo-z enables the full exploitation of this survey for studies of galaxy and large-scale structure evolution at high redshift.

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