- ID:
- ivo://CDS.VizieR/J/ApJ/791/128
- Title:
- Basic galaxy data for spiral-rich group members
- Short Name:
- J/ApJ/791/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope, the COS Science Team has conducted a high signal-to-noise survey of 14 bright QSOs. In a previous paper (Savage et al., 2014ApJS..212....8S), these far-UV spectra were used to discover 14 "warm" (T >= 10^5^ K) absorbers using a combination of broad Ly{alpha} and broad O VI absorptions. A reanalysis of a few of this new class of absorbers using slightly relaxed fitting criteria finds as many as 20 warm absorbers could be present in this sample. A shallow, wide spectroscopic galaxy redshift survey has been conducted around these sight lines to investigate the warm absorber environment, which is found to be spiral-rich groups or cluster outskirts with radial velocity dispersions {sigma}=250-750 km/s. While 2{sigma} evidence is presented favoring the hypothesis that these absorptions are associated with the galaxy groups and not with the individual, nearest galaxies, this evidence has considerable systematic uncertainties and is based on a small sample size so it is not entirely conclusive. If the associations are with galaxy groups, the observed frequency of warm absorbers (idN/dz = 3.5-5 per unit redshift) requires them to be very extended as an ensemble on the sky (~1 Mpc in radius at high covering factor). Most likely these warm absorbers are interface gas clouds whose presence implies the existence of a hotter (T ~ 10^6.5^ K), diffuse, and probably very massive (>10^11^ M_{sun}_) intra-group medium which has yet to be detected directly.
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- ID:
- ivo://CDS.VizieR/J/ApJS/252/29
- Title:
- BAT AGN Spectroscopic Survey. XX. Molecular gas
- Short Name:
- J/ApJS/252/29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the host-galaxy molecular gas properties of a sample of 213 nearby (0.01<z<0.05) hard-X-ray-selected active galactic nucleus (AGN) galaxies, drawn from the 70-month catalog of Swift's Burst Alert Telescope (BAT), with 200 new CO(2-1) line measurements obtained with the James Clerk Maxwell Telescope and the Atacama Pathfinder Experiment telescope. We find that AGN in massive galaxies (log(M_*_/M_{sun}_)>10.5) tend to have more molecular gas and higher gas fractions than inactive galaxies matched in stellar mass. When matched in star formation, we find AGN galaxies show no difference from inactive galaxies, with no evidence that AGN feedback affects the molecular gas. The higher molecular gas content is related to AGN galaxies hosting a population of gas-rich early types with an order of magnitude more molecular gas and a smaller fraction of quenched, passive galaxies (~5% versus 49%) compared to inactive galaxies. The likelihood of a given galaxy hosting an AGN (L_bol_>10^44^erg/s) increases by ~10-100 between a molecular gas mass of 10^8.7^M_{sun}_ and 10^10.2^M_{sun}_. AGN galaxies with a higher Eddington ratio (log(L/L_Edd_)>-1.3) tend to have higher molecular gas masses and gas fractions. The log(NH/cm^-2^)>23.4) of AGN galaxies with higher column densities are associated with lower depletion timescales and may prefer hosts with more gas centrally concentrated in the bulge that may be more prone to quenching than galaxy-wide molecular gas. The significant average link of host-galaxy molecular gas supply to supermassive black hole (SMBH) growth may naturally lead to the general correlations found between SMBHs and their host galaxies, such as the correlations between SMBH mass and bulge properties, and the redshift evolution of star formation and SMBH growth.
- ID:
- ivo://CDS.VizieR/J/AJ/141/99
- Title:
- BATC and SDSS photometry of A2589 cluster
- Short Name:
- J/AJ/141/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Smooth X-ray morphology and non-detection of a radio source at the center of A2589 indicate that it is a typical case of a well-relaxed regular galaxy cluster. In this paper, we present a multicolor photometry for A2589 (z=0.0414) with 15 intermediate bands in the Beijing-Arizona-Taiwan-Connecticut (BATC) system which covers an optical wavelength range from 3000{AA} to 10000{AA}. The spectral energy distributions (SEDs) for more than 5000 sources are achieved down to V~20mag in about a 1{deg}^2^ field. A2589 has also been covered by the Sloan Digital Sky Survey (SDSS) in photometric mode only. A cross-identification of the BATC-detected galaxies with the SDSS photometric catalog yields 1199 galaxies brighter than i=19.5mag, among which 68 member galaxies with known spectroscopic redshifts are found. After combining the SDSS five-band photometric data and the BATC SEDs, photometric redshift is applied to these galaxies to select faint member galaxies. The color-magnitude relation is taken as a further restriction of early-type cluster galaxies. As a result, 106 galaxies are newly selected as member galaxies.
- ID:
- ivo://CDS.VizieR/J/AJ/148/110
- Title:
- BATC ceimo light curves of 1ES 0806+52.4
- Short Name:
- J/AJ/148/110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the first systematic long-term multicolor optical monitoring of the BL Lacertae object 1ES 0806+52.4. The monitoring was performed in multiple passbands with a 60/90cm Schmidt telescope from 2005 December to 2011 February. The overall brightness of this object decreased from 2005 December to 2008 December but was regained after that. A sharp outburst probably occurred around the end of our monitoring program. Overlapping the long-term trend are some short-term small-amplitude oscillations. No intranight variability was found in the object, which is in accordance with the historical observations before 2005. By investigating the color behavior, we found a strong bluer-when-brighter chromatism for the long-term variability of 1ES 0806+52.4. The total amplitudes at the c, i, and o bands are 1.18, 1.12, and 1.02mag, respectively. The amplitudes tend to increase toward shorter wavelengths, which may be a major cause of the bluer-when-brighter chromatism. Such bluer-when-brighter chromatisms are also found in other blazars, such as S5 0716+714, OJ 287. The hard-X-ray data collected from the Swift/BAT archive was correlated with our optical data. No positive result was found, the reason for which may be that the hard-X-ray flux is a combination of the synchrotron and inverse Compton emission, but with different timescales and cadences under the leptonic synchrotron self-Compton model.
- 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
- 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.