- ID:
- ivo://CDS.VizieR/II/262
- Title:
- BATC Data Release One - BATC DR1
- Short Name:
- II/262
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multi-color photometry data of the project, "Large Field Multi-Color Sky Survey" supported by Beijing-Arizona-Taiwan-Connecticut (BATC) is presented. From 1995 to 2004, 110 58'x58' sky survey fields have been observed. First release of BATC catalog includes observation results for 511842 sources located in 70 sky survey fields. The whole release is divided into 70 files. Each file corresponds to one observation field. The BATC filter system includes 15 intermediate band filters, covering a range in optical wavelengths from 300 to 1000 nm. The telescope used is a 60/90 cm f/3 Schmidt telescope located at Xinglong Station of National Astronomical Observatories. A Ford Aerospace 2048x2048 CCD camera with 15 micron pixel size is mounted at the Schmidt focus of the telescope. The field of view of the CCD is 58'x58' with a plate scale of 1.7arcsec per pixel. The BATC magnitude system adopts the AB magnitude system, defining as M_batc_ = -2.5log(F_{nu}_) - 48.60 where F_{nu}_ is the flux per unit frequency in units of erg/s/cm^2^/Hz, and F_{nu}_={Sum}[d(log{nu})*f_{nu}_*R_{nu}_]/{Sum}[d(log{nu})*R_{nu}_] where R_{nu}_ represents the response of the system. Four Oke & Gunn (1983ApJ...266..713O) standards, HD 19445, HD 84937, BD+26 2606 and BD+17 4708 are observed in photometric nights for flux calibration. We provide catalogues down to i-band (666nm) about 20 mag with complete spectral energy distributions (SEDs) for each object. Typical error in photometry is about 0.02-0.05 mag. There is usually the deepest observation at i-band. Most of the catalogs use i-band data as their reference for coordinate calibration. While, "T0329","TA01" and "TA03" use j-band as reference. All colors in the "TA04" catalog have no photo calibration. For detailed information of the data reduction, please refer to: Zhou, X., Jiang, Z., Ma, J., et al. 2003, 2003A&A...397..361Z
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Search Results
- ID:
- ivo://CDS.VizieR/J/other/RAA/10.1
- Title:
- BATC photometry in A98 cluster
- Short Name:
- J/other/RAA/10.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An optical photometric observation with the Beijing-Arizona-Taiwan-Connecticut (BATC) multicolor system is carried out for A98 (z=0.104), a galaxy cluster with two large enhancements in X-ray surface brightness. Spectral energy distributions (SEDs) covering 15 intermediate bands are obtained for all sources detected down to V~20mag in a field of 58'x58'. After star-galaxy separation with color-color diagrams, a photometric redshift technique is applied to the galaxy sample for further membership determination. The color-magnitude relation is taken as a further restriction of the early-type cluster galaxies. As a result, a list of 198 faint member galaxies is achieved. Based
- ID:
- ivo://CDS.VizieR/J/other/RAA/12.1381
- Title:
- BATC photometry on A119
- Short Name:
- J/other/RAA/12.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents multicolor optical photometry of the nearby galaxy cluster Abell 119 (z=0.0442) with the Beijing-Arizona-Taiwan-Connecticut system of 15 intermediate bands. Within the BATC field of view of 58'x58', there are 368 galaxies with known spectroscopic redshifts, including 238 member galaxies (called sample I). Based on the spectral energy distributions of 1376 galaxies brighter than i_BATC_=19.5, the photometric redshift technique and the color-magnitude relation of early-type galaxies are applied to select faint member galaxies. As a result, 117 faint galaxies were selected as new member galaxies. Combined with sample I, an enlarged sample (called sample II) of 355 member galaxies is obtained. Spatial distribution and localized velocity structure for two samples demonstrate that A119 is a dynamically complex cluster with at least three prominent substructures in the central region within 1Mpc. A large velocity dispersion for the central clump indicates a merging along the line of sight. No significant evidence for morphology or luminosity segregations is found in either sample. With the PEGASE evolutionary synthesis model, the environmental effect on the properties of star formation is confirmed. Faint galaxies in the low-density region tend to have longer time scales of star formation, smaller mean stellar ages, and lower metallicities in their interstellar medium, which is in agreement with the context of the hierarchical cosmological scenario.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/2717
- Title:
- Bayesian analysis of resolved stellar spectra
- Short Name:
- J/MNRAS/448/2717
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce a Bayesian method for fitting faint, resolved stellar spectra in order to obtain simultaneous estimates of redshift and stellar-atmospheric parameters. We apply the method to thousands of spectra - covering 5160-5280{AA} at resolution R~20000 - that we have acquired with the MMT/Hectochelle fibre spectrograph for red giant and horizontal branch candidates along the line of sight to the Milky Way's dwarf spheroidal satellite in Draco. The observed stars subtend an area of ~4deg^2^, extending ~3 times beyond Draco's nominal 'tidal' radius. For each spectrum, we tabulate the first four moments - central value, variance, skewness and kurtosis - of posterior probability distribution functions representing estimates of the following physical parameters: line-of-sight velocity (v_los_), effective temperature (T_eff_), surface gravity (logg) and metallicity ([Fe/H]). After rejecting low-quality measurements, we retain a new sample consisting of 2813 independent observations of 1565 unique stars, including 1879 observations for 631 stars with (as many as 13) repeat observations. Parameter estimates have median random errors of v_los_=0.88km/s, T_eff_=162K, {sigma}logg=0.37dex and {sigma}[Fe/H]=0.20dex. Our estimates of physical parameters distinguish ~470 likely Draco members from interlopers in the Galactic foreground.
- ID:
- ivo://CDS.VizieR/J/ApJ/758/11
- Title:
- Bayesian distances to M31 satellites
- Short Name:
- J/ApJ/758/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In "A Bayesian Approach to Locating the Red Giant Branch Tip Magnitude (Part I)," a new technique was introduced for obtaining distances using the tip of the red giant branch (TRGB) standard candle. Here we describe a useful complement to the technique with the potential to further reduce the uncertainty in our distance measurements by incorporating a matched-filter weighting scheme into the model likelihood calculations. In this scheme, stars are weighted according to their probability of being true object members. We then re-test our modified algorithm using random-realization artificial data to verify the validity of the generated posterior probability distributions (PPDs) and proceed to apply the algorithm to the satellite system of M31, culminating in a three-dimensional view of the system. Further to the distributions thus obtained, we apply a satellite-specific prior on the satellite distances to weight the resulting distance posterior distributions, based on the halo density profile. Thus in a single publication, using a single method, a comprehensive coverage of the distances to the companion galaxies of M31 is presented, encompassing the dwarf spheroidals Andromedas I-III, V, IX-XXVII, and XXX along with NGC 147, NGC 185, M33, and M31 itself. Of these, the distances to Andromedas XXIV-XXVII and Andromeda XXX have never before been derived using the TRGB. Object distances are determined from high-resolution tip magnitude posterior distributions generated using the Markov Chain Monte Carlo technique and associated sampling of these distributions to take into account uncertainties in foreground extinction and the absolute magnitude of the TRGB as well as photometric errors. The distance PPDs obtained for each object both with and without the aforementioned prior are made available to the reader in tabular form. The large object coverage takes advantage of the unprecedented size and photometric depth of the Pan-Andromeda Archaeological Survey.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A81
- Title:
- Bayesian group finder applied to the 2MRS data
- Short Name:
- J/A+A/618/A81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We propose a probabilistic galaxy group detection algorithm based on marked point processes with interactions. The pattern of galaxy groups in a catalogue is seen as a random set of interacting objects. The positions and the interactions of these objects are governed by a probability density. The parameters of the probability density are chosen using a priori knowledge. The estimator of the unknown cluster pattern is given by the configuration of objects maximising the proposed probability density. Adopting the Bayesian framework, the proposed probability density is maximised using a simulated annealing (SA) algorithm. At fixed temperature, the SA algorithm is a Monte Carlo sampler of the probability density. Hence, the method provides "for free" additional information such as the probabilities that a point or two points in the observation domain belong to the cluster pattern, respectively. These supplementary tools allow the construction of tests and techniques to validate and to refine the detection result. To test the feasibility of the proposed methodology, we applied it to the well-studied 2MASS Redshift Survey (2MRS) data set. Compared to previously published Friends-of-Friends (FoF) group finders, the proposed Bayesian group finder gives overall similar results. However, for specific applications, like the reconstruction of the local Universe, the details of the grouping algorithms are important.
- ID:
- ivo://CDS.VizieR/J/A+A/560/A78
- Title:
- B-Band catalog of sources in Abell 3376
- Short Name:
- J/A+A/560/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The cluster Abell 3376 is a merging cluster of galaxies at redshift z=0.046. It is famous mostly for its giant radio arcs, and shows an elongated and highly substructured X-ray emission, but has not been analysed in detail at optical wavelengths. To improve our understanding of the effects of the major cluster merger on the galaxy properties, we analyse the galaxy luminosity function (GLF) in the B band in several regions as well as the dynamical properties of the substructures.
- ID:
- ivo://CDS.VizieR/J/MNRAS/453/1223
- Title:
- BCG high radio-frequency properties
- Short Name:
- J/MNRAS/453/1223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We consider the high radio-frequency (15-353GHz) properties and variability of 35 brightest cluster galaxies (BCGs). These are the most core-dominated sources drawn from a parent sample of more than 700 X-ray selected clusters, thus allowing us to relate our results to the general population. We find that >=6.0 percent of our parent sample (>=15.1 percent if only cool-core clusters are considered) contain a radio source at 150GHz of at least 3mJy (~1x10^23^W/Hz at our median redshift of z~0.13). Furthermore, >=3.4 percent of the BCGs in our parent sample contain a peaked component (Gigahertz Peaked Spectrum, GPS) in their spectra that peaks above 2GHz, increasing to >=8.5 percent if only cool-core clusters are considered. We see little evidence for strong variability at 15GHz on short (week-month) time-scales although we see variations greater than 20 percent at 150GHz over six-month time frames for 4 of the 23 sources with multi-epoch observations. Much more prevalent is long-term (year-decade time-scale) variability, with average annual amplitude variations greater than 1 percent at 15GHz being commonplace. There is a weak trend towards higher variability as the peak of the GPS-like component occurs at higher frequency. We demonstrate the complexity that is seen in the radio spectra of BCGs and discuss the potentially significant implications of these high-peaking components for Sunyaev-Zel'dovich cluster searches.
- ID:
- ivo://CDS.VizieR/J/A+A/649/A42
- Title:
- BCG up to z=1.80 physical properties
- Short Name:
- J/A+A/649/A42
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Brightest cluster galaxies (BCGs) have grown by accreting numerous smaller galaxies and can be used as tracers of cluster formation and evolution in the cosmic web. However, there is still a controversy on the main epoch of formation of BCGs, since some authors believe they have already formed before redshift z=2, while others still find them to evolve at more recent epochs. We aim to analyse the physical properties of a large sample of BCGs covering a wide redshift range up to z=1.8 and analysed in a homogeneous way, to see if their characteristics vary with redshift. As a first step, we also present a new tool to define for each cluster which galaxy is the BCG. For a sample of 137 clusters with HST images in the optical and/or infrared, we analyse the BCG properties by applying GALFIT with one or two Sersic components. For each BCG, we compute the Sersic index, effective radius, major axis position angle, surface brightness. We then search for correlations of these quantities with redshift. We find that BCGs follow the Kormendy relation (between the effective radius and the mean surface brightness), with a slope that remains constant with redshift, but with a variation with redshift of the ordinate at the origin. Although the trends are faint, we find that both the absolute magnitudes and effective radii tend to become respectively brighter and bigger with decreasing redshift. On the other hand, we find no significant correlation of the mean surface brightnesses or Sersic indices with redshift. The major axes of the cluster elongations and of the BCGs agree within 30 degrees for 73% of our clusters at redshift z<=0.9. Our results agree with the BCGs being mainly formed before redshift z=2. The alignment of the major axes of BCGs with their clusters agree with the general idea that BCGs form at the same time as clusters by accreting matter along the filaments of the cosmic web.
- ID:
- ivo://CDS.VizieR/J/AJ/148/75
- Title:
- Bent-tailed radio galaxies Chandra Deep Field South
- Short Name:
- J/AJ/148/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the 1.4GHz Australia Telescope Large Area Survey, supplemented by the 1.4GHz Very Large Array images, we undertook a search for bent-tailed (BT) radio galaxies in the Chandra Deep Field South. Here we present a catalog of 56 detections, which include 45 BT sources, 4 diffuse low-surface-brightness objects (1 relic, 2 halos, and 1 unclassified object), and a further 7 complex, multi-component sources. We report BT sources with rest-frame powers in the range 10^22^<=P_1.4 GHz_<=10^26^W/Hz, with redshifts up to 2 and linear extents from tens of kiloparsecs up to about 1Mpc. This is the first systematic study of such sources down to such low powers and high redshifts and demonstrates the complementary nature of searches in deep, limited area surveys as compared to shallower, large surveys. Of the sources presented here, one is the most distant BT source yet detected at a redshift of 2.1688. Two of the sources are found to be associated with known clusters: a wide-angle tail source in A3141 and a putative radio relic which appears at the infall region between the galaxy group MZ 00108 and the galaxy cluster AMPCC 40. Further observations are required to confirm the relic detection, which, if successful, would demonstrate this to be the least powerful relic yet seen with P_1.4GHz_=9x10^22^W/Hz. Using these data, we predict future 1.4GHz all-sky surveys with a resolution of ~10 arcsec and a sensitivity of 10{mu}Jy will detect of the order of 560,000 extended low-surface-brightness radio sources of which 440,000 will have a BT morphology.
