- ID:
- ivo://CDS.VizieR/J/MNRAS/467/4220
- Title:
- Galaxies inside 120 arcsec of HE 0435-1223
- Short Name:
- J/MNRAS/467/4220
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on spectroscopy and multiband wide-field observations of the gravitationally lensed quasar HE 0435-1223, we determine the probability distribution function of the external convergence {kappa}_ext_ for this system. We measure the under/overdensity of the line of sight towards the lens system and compare it to the average line of sight throughout the Universe, determined by using the CFHTLenS (The Canada France Hawaii Lensing Survey) as a control field. Aiming to constrain {kappa}_ext_ as tightly as possible, we determine under/overdensities using various combinations of relevant informative weighting schemes for the galaxy counts, such as projected distance to the lens, redshift and stellar mass. We then convert the measured under/overdensities into a {kappa}_ext_ distribution, using ray-tracing through the Millennium Simulation. We explore several limiting magnitudes and apertures, and account for systematic and statistical uncertainties relevant to the quality of the observational data, which we further test through simulations. Our most robust estimate of {kappa}_ext_ has a median value {kappa}^med^_ext_=0.004 and a standard deviation {sigma}_{kappa}_=0.025. The measured {sigma}_{kappa}_ corresponds to 2.5 per cent relative uncertainty on the time delay distance, and hence the Hubble constant H_0_ inferred from this system. The median {kappa}^med^_ext_ value varies by ~0.005 with the adopted aperture radius, limiting magnitude and weighting scheme, as long as the latter incorporates galaxy number counts, the projected distance to the main lens and a prior on the external shear obtained from mass modelling. This corresponds to just ~0.5 per cent systematic impact on H_0_. The availability of a well-constrained {kappa}_ext_ makes HE 0435-1223 a valuable system for measuring cosmological parameters using strong gravitational lens time delays.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/640/A30
- Title:
- Galaxies in the Perseus cluster field
- Short Name:
- J/A+A/640/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the galaxies brighter than B~20 in the field of the Perseus cluster. The galaxies were selected on Schmidt CCD images in B and Halpha in combination with SDSS images. The survey field roughly covers the virial radius of the cluster. The galaxy sample is used for analysing cluster properties, such as radial profiles, indications of sub-structure, virial mass, and viral radius and is applied for a study of the cluster galaxy population with an emphasis on morphological types and peculiarities, star formation rates and active galactic nuclei.
- ID:
- ivo://CDS.VizieR/J/A+A/413/771
- Title:
- Galaxies in the Tycho-2 catalogue
- Short Name:
- J/A+A/413/771
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The accuracy of the link of the proper motion system of astrometric satellite missions like AMEX and GAIA is discussed. Monte-Carlo methods were used to simulate catalogues of positions and proper motions of quasars and galaxies to test the link. The main conclusion is, that future satellite missions like GAIA may be "self-calibrated" by their measurements of QSOs, while additional measurements from radio stars or HST-data are needed to calibrate the less deep reaching astrometric satellite missions of AMEX type.
- ID:
- ivo://CDS.VizieR/J/ApJ/816/98
- Title:
- Galaxies in X-ray clusters with DES. I. Stellar mass
- Short Name:
- J/ApJ/816/98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the science verification data of the Dark Energy Survey for a new sample of 106 X-ray selected clusters and groups, we study the stellar mass growth of bright central galaxies (BCGs) since redshift z~1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into an analysis of a redshift-dependent BCG-cluster mass relation, m_*_{propto}(M_200_/1.5x10^14^M_{sun}_)^0.24+/-0.08^(1+z)^-0.19+/-0.34, and compare the observed relation to the model prediction. We estimate the average growth rate since z=1.0 for BCGs hosted by clusters of M_200,z_=10^13.8^M_{sun}_; at z=1.0: m_*,BCG_ appears to have grown by 0.13+/-0.11dex, in tension at the ~2.5{sigma} significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the build-up of extended intracluster light after z=1.0 may alleviate this tension in BCG growth rates.
- ID:
- ivo://CDS.VizieR/J/ApJ/742/125
- Title:
- Galaxies in X-ray groups. I. COSMOS memberships
- Short Name:
- J/ApJ/742/125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Understanding the mechanisms that lead dense environments to host galaxies with redder colors, more spheroidal morphologies, and lower star formation rates than field populations remains an important problem. As most candidate processes ultimately depend on host halo mass, accurate characterizations of the local environment, ideally tied to halo mass estimates and spanning a range in halo mass and redshift, are needed. In this work, we present and test a rigorous, probabilistic method for assigning galaxies to groups based on precise photometric redshifts and X-ray-selected groups drawn from the COSMOS field. The groups have masses in the range 10^13^<~M_200c_/M_{sun}_<~10^14^ and span redshifts 0<z<1. We characterize our selection algorithm via tests on spectroscopic subsamples, including new data obtained at the Very Large Telescope, and by applying our method to detailed mock catalogs. We find that our group member galaxy sample has a purity of 84% and completeness of 92% within 0.5R_200c_. We measure the impact of uncertainties in redshifts and group centering on the quality of the member selection with simulations based on current data as well as future imaging and spectroscopic surveys. As a first application of our new group member catalog which will be made publicly available, we show that member galaxies exhibit a higher quenched fraction compared to the field at fixed stellar mass out to z~1, indicating a significant relationship between star formation and environment at group scales. We also address the suggestion that dusty star-forming galaxies in such groups may impact the high-l power spectrum of the cosmic microwave background and find that such a population cannot explain the low power seen in recent Sunyaev-Zel'dovich measurements.
- ID:
- ivo://CDS.VizieR/J/MNRAS/415/431
- Title:
- Galaxies with wide HI profiles
- Short Name:
- J/MNRAS/415/431
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the nature of objects in a complete sample of 28 galaxies selected from the first sky area fully covered by the Arecibo Legacy Fast ALFA (ALFALFA) survey, being well detected and having HI profiles wider than 550km/s. The selection does not use brightness, morphology or any other property derived from optical or other spectral bands. We investigate the degree of isolation, the morphology and other properties gathered or derived from open data bases and show that some objects have wide HI profiles probably because they are disturbed or are interacting, or might be confused in the ALFALFA beam.
- ID:
- ivo://CDS.VizieR/J/ApJS/144/21
- Title:
- Galaxy and Magellanic Clouds OB and WR stars
- Short Name:
- J/ApJS/144/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have generated a set of far-ultraviolet stellar libraries using spectra of OB and Wolf-Rayet stars in the Galaxy and the Large and Small Magellanic Cloud. The spectra were collected with the Far Ultraviolet Spectroscopic Explorer and cover a wavelength range from 1003.1 to 1182.7{AA} at a resolution of 0.127{AA}. The libraries extend from the earliest O to late-O and early-B stars for the Magellanic Cloud and Galactic libraries, respectively.
- ID:
- ivo://CDS.VizieR/J/MNRAS/413/971
- Title:
- Galaxy And Mass Assembly (GAMA) DR1
- Short Name:
- J/MNRAS/413/971
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galaxy and Mass Assembly (GAMA) survey has been operating since 2008 February on the 3.9-m Anglo-Australian Telescope using the AAOmega fibre-fed spectrograph facility to acquire spectra with a resolution of R~1300 for 120862 Sloan Digital Sky Survey selected galaxies. The target catalogue constitutes three contiguous equatorial regions centred at 9h (G09), 12h (G12) and 14.5h (G15) each of 12x4deg^2^ to limiting fluxes of r_pet_<19.4, r_pet_<19.8 and r_pet_<19.4 mag, respectively (and additional limits at other wavelengths). Spectra and reliable redshifts have been acquired for over 98 per cent of the galaxies within these limits. Here we present the survey footprint, progression, data reduction, redshifting, re-redshifting, an assessment of data quality after 3yr, additional image analysis products (including ugrizYJHK photometry, Sersic profiles and photometric redshifts), observing mask and construction of our core survey catalogue (GamaCore). From this we create three science-ready catalogues: GamaCoreDR1 for public release, which includes data acquired during year 1 of operations within specified magnitude limits (2008 February to April); GamaCoreMainSurvey containing all data above our survey limits for use by the GAMA Team and collaborators; and GamaCoreAtlasSV containing year 1, 2 and 3 data matched to Herschel-ATLAS science demonstration data. These catalogues along with the associated spectra, stamps and profiles can be accessed via the GAMA website: http://www.gama-survey.org/
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/2087
- Title:
- Galaxy And Mass Assembly (GAMA): DR2
- Short Name:
- J/MNRAS/452/2087
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galaxy And Mass Assembly (GAMA) survey is one of the largest contemporary spectroscopic surveys of low redshift galaxies. Covering an area of ~286deg^2^ (split among five survey regions) down to a limiting magnitude of r<19.8mag, we have collected spectra and reliable redshifts for 238000 objects using the AAOmega spectrograph on the Anglo-Australian Telescope. In addition, we have assembled imaging data from a number of independent surveys in order to generate photometry spanning the wavelength range 1nm-1m. Here, we report on the recently completed spectroscopic survey and present a series of diagnostics to assess its final state and the quality of the redshift data. We also describe a number of survey aspects and procedures, or updates thereof, including changes to the input catalogue, redshifting and re-redshifting, and the derivation of ultraviolet, optical and near-infrared photometry. Finally, we present the second public release of GAMA data. In this release, we provide input catalogue and targeting information, spectra, redshifts, ultraviolet, optical and near-infrared photometry, single-component Sersic fits, stellar masses, H{alpha}-derived star formation rates, environment information, and group properties for all galaxies with r<19.0mag in two of our survey regions, and for all galaxies with r<19.4mag in a third region (72225 objects in total). The data base serving these data is available at http://www.gama-survey.org/.
- ID:
- ivo://CDS.VizieR/J/MNRAS/474/3875
- Title:
- Galaxy And Mass Assembly (GAMA): DR3
- Short Name:
- J/MNRAS/474/3875
- Date:
- 19 Jan 2022 09:03:58
- Publisher:
- CDS
- Description:
- We describe data release 3 (DR3) of the Galaxy And Mass Assembly (GAMA) survey. The GAMA survey is a spectroscopic redshift and multiwavelength photometric survey in three equatorial regions each of 60.0deg^2^ (G09, G12, and G15), and two southern regions of 55.7deg^2^ (G02) and 50.6deg^2^ (G23). DR3 consists of: the first release of data covering the G02 region and of data on H-ATLAS (Herschel - Astrophysical Terahertz Large Area Survey) sources in the equatorial regions; and updates to data on sources released in DR2. DR3 includes 154809 sources with secure redshifts across four regions. A subset of the G02 region is 95.5 per cent redshift complete to r<19.8mag over an area of 19.5deg^2^, with 20086 galaxy redshifts, that overlaps substantially with the XXL survey (X-ray) and VIPERS (redshift survey). In the equatorial regions, the main survey has even higher completeness (98.5 per cent), and spectra for about 75 per cent of H-ATLAS filler targets were also obtained. This filler sample extends spectroscopic redshifts, for probable optical counterparts to H-ATLAS submillimetre sources, to 0.8mag deeper (r<20.6mag) than the GAMA main survey. There are 25814 galaxy redshifts for H-ATLAS sources from the GAMA main or filler surveys. GAMA DR3 is available at the survey website (www.gama-survey.org/dr3/).
